KR20080108451A - Motor system - Google Patents

Abstract

Provided is a motor system, which can detect the angle of rotation of a rotor highly precisely while avoiding atmospheric contamination and which can adjust a detector easily. Two inner rotors (30 and 30') are arranged across two stators (29 and 29') on the outer sides of an axial direction so that they can arrange resolvers confronting the inner rotors (30 and 30'), individually on the outer sides of the axial direction. In the case of these arrangement, the adjusting operations can be performed from the two sides of the axial direction without separating direct drive motors (D1 and D2), so that the angles of the stators and the resolvers can be easily adjusted even with the two axes thereby to make the adjusting works efficient. Moreover, it is possible to prevent the angle positioning precision from being degraded, as might otherwise be caused by a commutation deviation, to enhance the interchangeability of a drive control circuit for a two-axis coaxial motor, and to suppress the total height of the motor system thereby to provide a compact constitution. ® KIPO & WIPO 2009

Description

Motor system {MOTOR SYSTEM}

The present invention relates to a motor system using a plurality of direct drive motors used in an atmosphere outside the atmosphere, for example, in a vacuum.

For example, in a semiconductor manufacturing apparatus or the like, the work to be processed is performed in an ultra-high vacuum atmosphere in a vacuum chamber in order to remove impurities as much as possible. As the actuator used in such a case, for example, in a drive motor of a workpiece positioning apparatus, since a lubricant containing volatile components such as grease common to a drive shaft cannot be used, bearing a soft metal such as gold or silver is used. It improves lubricity by plating on inner and outer rings. In addition, the coil insulation of the drive motor, the wiring covering and the adhesive of the laminated magnetic pole are also required to select a stable material having excellent heat resistance and low emission gas.

In particular, in recent years, the degree of integration of semiconductors has increased, and at the same time, a higher density has been developed due to the miniaturization of IC pattern width. In order to manufacture a wafer that can cope with this miniaturization, high uniformity with respect to wafer quality is required. In order to meet the demand, the reduction of the impurity gas concentration in the low pressure gas processing chamber of the wafer is more important. In addition, in order to perform fine processing as required, a very high precision positioning device is required. In view of the above, the conventional actuators point out various problems as follows.

That is, in the case of a drive motor used in a vacuum chamber having an ultra-vacuum atmosphere, even if a stable material having excellent heat resistance and low emission gas is selected for the coil insulation material or wiring coating of the drive motor, as long as it is an organic insulation material, it is microscopic. It is porous and has numerous holes on its surface. Once this is exposed to the atmosphere, gas, water molecules, etc. are put in the hole on the surface thereof to occlude. Since degassing which removes such occlusion impurity molecules by vacuum exhaust requires a long time, the fall of production efficiency is difficult to avoid. In addition, since there is no heat dissipation due to air convection in vacuum, when a local rise of the coil temperature is caused, the resistance of the portion increases, and heat generation is accelerated, leading to the loss of the coil insulation film. On the other hand, it is possible to reduce the adsorption impurity molecules by using an inorganic material for the coil insulation material and by using a sheath wire of a stainless steel pipe as the wiring. In this case, however, the cost is very expensive, and the proportion of conductors such as copper in the coil winding space is reduced, resulting in an increase in electrical resistance, resulting in a reduction in capacity of the motor.

In response to this problem, a direct drive for arranging a stator inside the vacuum encapsulation body, an output member outside thereof, and driving a frog leg arm using an output member, that is, a rotor, is used. The motor is described in Patent Document 1. According to the direct drive motor of patent document 1, since the coil insulation material, wiring coating, etc. which accompany a stator are arrange | positioned inside the vacuum sealing body hold | maintained at atmospheric pressure, the storage impurity molecule in the case of arrange | positioning them in a vacuum chamber Emission problems and heat generation problems can be avoided.

Patent Document 1: Japanese Unexamined Patent Publication No. 2000-69741

By the way, in order to perform a high precision drive, although it is necessary to use the high precision detector which detects the rotation angle position of a direct drive motor, there exists a request that it wants to simplify the adjustment work more. By the way, although there is no specification in patent document 1, it can be considered that in the direct drive motor of such a prior art, the detector which detects the rotation angle position of the lower ring-shaped boss is disassembled by disassembling the upper ring-shaped boss. . However, in order to adjust the detector which detects the rotation angle position of the lower ring-shaped boss, adjustment takes time when the upper ring-shaped boss is to be disassembled one by one.

In addition, when the multi-axis direct drive motors are stacked on the same axis, it is necessary to stack the motors for each axis, the height of each axis constituting the motor becomes thick, the layout of the wiring becomes complicated, and the number of parts also increases. In particular, in order to install the motor in a vacuum chamber in which the capacity is limited, it is necessary to limit the height of the motor, and separate the atmosphere environment in which the stator and the rotor are arranged in the air gap where the stator and the rotor face each other. In the case of constituting a nonmagnetic bulkhead and a motor magnetic coupling, there is a problem that it is difficult to arrange the motor wiring and the resolver wiring on the outer periphery of each axis.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and an object thereof is to provide a motor system capable of detecting a rotation angle of a rotor with high accuracy and easily adjusting a detector while avoiding atmospheric pollution.

[Invention 1]

The motor system of the first invention is a motor system coaxially combining a first direct drive motor and a second direct drive motor used in an atmosphere outside the atmosphere,

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The inner rotors of the first and second direct drive motors are arranged outside the axial direction with the stators of the first and second direct drive motors interposed therebetween.

Thereby, since the inner rotor of the said 1st and said 2nd direct drive motor makes the stator of the said 1st and said 2nd direct drive motor between, and is arrange | positioned outward in the axial direction, the said 1st And the detectors of the second direct drive motor can be arranged on both sides in the axial direction, and therefore, when adjusting them, the adjustment work can be performed from both sides in the axial direction without disconnecting the first and second direct drive motors. Since it can be performed, the angle of a stator and a resolver can be easily adjusted biaxially, and the adjustment work can be made more efficient. In addition, it is possible to provide a compact configuration by reducing the overall height of the motor system.

[Invention 2]

The motor system of invention 2 is a motor system of invention 1, wherein the detectors of the first and second direct drive motors are connected to both sides in the axial direction in a state in which the first and second direct drive motors are connected to each other. It is characterized in that the adjustment is possible from.

As a result, it is preferable that the detectors of the first and second direct drive motors are adjustable from both sides in the axial direction while the first and second direct drive motors are connected to each other.

[Invention 3]

In the motor system according to the third aspect of the invention, in the motor system according to the first or second aspect of the invention, at one end in the axial direction of the housing, a recess is fitted to the convex portion formed at the other end in the axial direction of the other housing, and the recess and the convex portion are formed. A plurality of pairs of the first and second direct drive motors are connected by fitting.

As a result, in a direct drive motor used in an atmosphere outside the atmosphere, a housing, a partition wall extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition wall, It has a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting the rotational position of the inner rotor, the stator drives the outer rotor, and the inner rotor co-rotates with the outer rotor, By placing the detector inside the partition wall, the storage impurity molecules of the wiring covering are prevented from contaminating the atmosphere outside the partition wall. In particular, when the magnetic shield is disposed between at least one of the outer rotors, the inner rotors, and the stators in the adjacent direct drive motors, the effects of leakage magnetic flux, electromagnetic noise, etc. generated from the rotor and the stator may be affected. Impact on the rotor and the stator in the adjacent direct drive motor can be suppressed. Therefore, the motor system can be thinned.

[Invention 4]

The motor system of the fourth invention is the motor system of the third invention, characterized in that a member extending between shafts is provided between the housing and the other housing.

Thereby, the recessed part which fits into the convex part formed in the axial direction other end of another housing is formed in the axial direction end of the said housing, and it fits the said recessed part and the said convex part, Since a plurality of pairs of direct drive motors are connected, for example, a plurality of pairs of frog leg arms can be driven.

[Invention 5]

The motor system according to the fifth aspect of the present invention is the motor system according to the first or second aspect of the invention, wherein a plurality of pairs of the first and second direct drive motors are connected by fastening end portions of the partition wall in the axial direction.

Thus, when connecting a plurality of pairs of the first and second direct drive motors, a member extending between shafts is provided between the housing and the other housing, or one end of the partition wall in the axial direction is connected. The range of leg arms can be extended to a point closer to the shaft.

[Invention 6]

The motor system of the sixth invention is the motor system according to any one of the inventions 1 to 5, wherein wiring in the stator of the first and second direct drive motors extends between the first and second direct drive motors. It is characterized by being.

Thereby, the wiring process is simplified if the wiring in the stator of the said 1st and said 2nd direct drive motor extends between the said 1st and said 2nd direct drive motor.

[Invention 7]

The direct drive motor of the seventh invention is a direct drive motor used in an atmosphere outside the atmosphere,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator and an inner rotor disposed on an atmospheric side with respect to the partition wall;

Having a detector for detecting the rotational speed of the inner rotor,

The stator is characterized in that for driving the outer rotor and the inner rotor at the same time.

Thereby, in a direct drive motor used in an atmosphere outside the atmosphere, the housing, a partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere, an outer rotor disposed outside the seat against the partition wall, And a stator and an inner rotor disposed on an atmospheric side with respect to the partition wall, and a detector for detecting a rotational speed of the inner rotor, and the stator drives the outer rotor and the inner rotor simultaneously, thereby providing the detector with By placing it on the atmosphere side, the storage impurity molecules of the wiring coating are prevented from contaminating the atmosphere outside the atmosphere than the partition wall, and the stator drives the outer rotor and the inner rotor simultaneously, thereby allowing the inner side to be detected by the detector. The rotation angle of the outer rotor is determined by detecting the rotation angle of the rotor. It can be obtained even allow.

[Invention 8]

The direct drive motor of the eighth aspect of the invention is the direct drive motor of the seventh aspect, wherein the number of magnetic poles is the same as that of the outer rotor and the inner rotor.

Thereby, when the number of magnetic poles is the same as the said outer rotor and the said inner rotor, since the rotation angles of the said outer rotor and the said inner rotor become the same, the rotation angle of the said outer rotor is detected by detecting the rotation angle of the said inner rotor. You can get the angle immediately. However, this invention is not limited to this, For example, you may make the number of poles of the said outer rotor and the number of poles of the said inner rotor of the said inner rotor be multiples of one or an integral number.

[Invention 9]

The direct drive motor of the ninth aspect of the invention is the direct drive motor of the seventh or eighth aspect of the invention, wherein the inner rotor is disposed radially inward of the stator.

Thereby, if an inner rotor is arrange | positioned inside the radial direction of the said stator, although driving of the said stator can be reliably performed, you may arrange | position so that it may shift to an axial direction.

[Invention 10]

The direct drive motor of the tenth invention is a direct drive motor used in an atmosphere outside the atmosphere,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition and a rotor for magnetic coupling integrally rotating with the outer rotor;

A stator disposed on the air side with respect to the partition wall and driving the outer rotor;

An inner rotor disposed on the atmosphere side with respect to the partition wall;

Having a detector for detecting the rotational speed of the inner rotor,

The rotor for magnetic coupling and the inner rotor rotate in synchronization with a magnetic coupling action.

As a result, in a direct drive motor used in an atmosphere outside the atmosphere, a housing, a partition wall extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition wall, and the outside Rotor for magnetic coupling that rotates integrally with the rotor, a stator disposed on the air side with respect to the partition wall, and driving the outer rotor, an inner rotor disposed on the air side with respect to the partition wall, and a rotational speed of the inner rotor. Has a detector for detecting the magnetic coupling rotor and the inner rotor in synchronism with the magnetic coupling action, so that the detector is placed on the air side rather than the partition wall. Contamination of the atmosphere outside the atmosphere than the partition wall is prevented, and by the magnetic coupling action Group magnetic couple the rotation of the inner rotor to rotate in synchronism with the rotor rings as detected by the detector can be determined so the precision rotation of the outer rotor.

In the present invention, the "outer rotor" and the "magnetic coupling rotor" are different in form, but for example, when a driving magnet and a magnet for magnetic coupling are provided in a single rotor, Since the part of the rotor provided with the magnet is the "outer rotor" and the part of the rotor provided with the magnet for magnetic coupling is called "the rotor for magnetic coupling", it is also included in this invention.

[Invention 11]

In the direct drive motor of the eleventh aspect of the invention, in the direct drive motor of the tenth aspect of the invention, the partition wall suppresses the peak value of the gain of the resonance frequency in the magnetic coupling system.

As a result, the partition wall between the atmospheric rotor and the atmospheric outer rotor enables positioning with less vibration due to the effect of suppressing the peak value of the gain of the resonance frequency in the magnetic coupling system.

[Invention 12]

In the direct drive motor of the twelfth aspect of the present invention, in the direct drive motor used in an atmosphere outside the atmosphere,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The partition has an attachment portion attached to the housing, a tubular portion and a bottom portion extending between the outer rotor, the stator and the inner rotor, and the bottom portion is axially with respect to the housing. It is characterized by not being constrained.

As a result, in a direct drive motor used in an atmosphere outside the atmosphere, a housing, a partition wall extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition wall, It has a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting the rotational position of the inner rotor, the stator drives the outer rotor, and the inner rotor co-rotates with the outer rotor, By placing the detector on the side of the partition wall, it is possible to prevent the storage impurity molecules in the wiring covering from contaminating the atmosphere outside the partition wall. In addition, the partition wall has an attachment portion attached to the housing, a tubular portion extending between the outer rotor, the stator and the inner rotor, and a bottom portion, the bottom portion being axially relative to the housing. Since the bottom is not pressed or pulled by the housing even when dimensional error or deformation occurs in the partition due to dimensional accuracy, mechanical accuracy, or temperature change, the axial stress or bending of the partition The stress can be relaxed, whereby seal failure, breakage, and the like can be prevented. Moreover, since the attachment part of the said partition and the said housing to which it is attached do not need to be processed with high precision, a direct drive motor of a lower cost can be provided.

[Invention 13]

The direct drive motor of the thirteenth invention is a direct drive motor used in an atmosphere outside the atmosphere,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The lump has an attachment portion attached to the housing, a tubular portion extending between the outer rotor, the stator and the inner rotor, and a connecting portion connecting the attachment portion and the normal portion, The thickness of the connection portion is characterized in that thinner than the thickness of the attachment portion.

Thereby, with respect to the effect of the twelfth aspect, the partition wall has an attachment portion attached to the housing, a tubular portion extending between the outer rotor, the stator and the inner rotor, and the attachment portion. Since the thickness of the said attachment part is thicker than the thickness of the said connection part, even if the deformation | transformation in the said partition is caused by dimensional precision, mechanical precision, and temperature change, the said thin part connection part has a connection part which connects the said cylindrical part. By deforming first, the axial stress and the bending stress of the partition wall can be alleviated, whereby seal failure, breakage, and the like can be prevented. Therefore, since the attachment part of the said partition and the said housing to which it is attached do not need to be processed with high precision, a direct drive motor of a lower cost can be provided.

[Invention 14]

The direct drive motor of the fourteenth aspect of the invention is the direct drive motor of the thirteenth aspect, wherein the connecting portion has a wave shape.

Thereby, as long as the said connection part is wave-shaped, such a site | part can achieve stress relaxation more effectively.

[Invention 15]

The motor system of the fifteenth aspect of the present invention provides a motor system in which a plurality of direct drive motors are coaxially coupled to each other in an atmosphere outside the atmosphere.

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

The outer rotor of at least one direct drive motor is supported by a bearing against the outer rotor of another direct drive motor.

As a result, in a motor system in which a plurality of direct drive motors are coaxially coupled to each other in an atmosphere outside the atmosphere, each direct drive motor extends from the housing, the housing, and partition walls separating the atmosphere side and the atmosphere outside. And an outer rotor disposed outside the atmosphere with respect to the partition wall, a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting a rotational position of the inner rotor, wherein the stator drives the outer rotor. In addition, since the inner rotor co-rotates with the outer rotor, placing the detector inside the partition wall prevents the storage impurity molecules of the wiring covering from contaminating the atmosphere outside the partition wall. In addition, since the outer rotor of at least one direct drive motor is supported by a bearing with respect to the outer rotor of another direct drive motor, the coaxiality between the outer rotors of a plurality of direct drive motors can be increased, and the prog When driving a leg arm, the operation precision can be improved. When the outer rotor of the one direct drive motor is removed, the bearing supporting the outer rotor can be exposed, so that the inspection and removal can be easily performed, thereby improving the maintainability. In addition, since only the outer rotor outside the partition wall needs to be removed, there is no need to remove the entire direct drive motor, so that a leak check or the like is unnecessary at the time of reassembly, thereby improving assembly performance.

[Invention 16]

The motor system of the sixteenth invention is characterized in that in the motor system of onset 15, the partition wall of one direct drive motor is common with the partition wall of another direct drive motor.

Thereby, since the partition of one direct drive motor is common with the partition of another direct drive motor, since the number of parts and a seal point can be reduced, it is preferable.

[Invention 17]

The motor system of the seventeenth aspect of the invention is the motor system of the sixteenth aspect, wherein the partition wall has a cup shape.

Thereby, if the said partition is cup-shaped, since the number of components will be small and a seal point will also decrease, it is preferable. However, the partition wall is not limited to the cup shape, and the cylinder and the disc may be combined to be integrated by welding or the like, or the truncated cone and the disc reduced in the direction of detaching the outer rotor may be combined.

[Invention 18]

In the motor system of the eighteenth aspect of the present invention, there is provided a motor system in which a plurality of direct drive motors are coaxially coupled to each other.

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer side disposed outside the atmosphere with respect to the partition wall,

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The outer rotor of one direct drive motor is supported by a bearing against one end of the housing, and the outer rotor of another direct drive motor is supported by a bearing against the other end of the housing. It is characterized by that.

As a result, in a motor system in which a plurality of direct drive motors are coaxially coupled to each other in an atmosphere other than the atmosphere, each direct drive motor extends from the housing, the housing, and partition walls separating the atmospheric side and the outside of the atmosphere, An outer rotor disposed outside the atmosphere with respect to the partition wall, a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting a rotational position of the inner rotor, the stator driving the outer rotor Since the inner rotor co-rotates with the outer rotor, placing the detector inside the partition wall prevents the occlusion molecules of the wiring covering from contaminating the atmosphere outside the partition wall. In addition, since the outer rotor of the direct drive motor is supported by bearings at both ends of the housing, it is difficult to affect the mechanical precision of each other. Therefore, it is possible to provide a motor system having a large load load and a large allowable moment.

(Invention 19)

The motor system of the nineteenth invention is characterized in that, in the motor system of the eighteenth invention, an end shape of one of the housings is capable of detaching the outer rotor of all the direct drive motors in the axial direction.

Thereby, if the end shape of one of the housing | casings which support a partition structure is able to remove the said outer rotor of a direct drive motor to an axial direction, all outer rotors can be removed from a partition and checked by it In addition, since the removal can be performed easily, the maintainability is also improved. In addition, since only the outer rotor outside the partition wall needs to be removed, the entire direct drive motor does not need to be removed, and a leak check or the like is unnecessary at the time of reassembly, thereby improving assembly performance.

[Invention 20]

The motor system of the 20th invention is the motor system of the 18th invention, wherein the partition wall of one direct drive motor is common with the partition wall of another direct drive motor.

Thereby, since the partition number of one direct drive motor is common with the said partition wall of another direct drive motor, since the number of components and a seal point can be reduced, it is preferable.

[Invention 21]

The motor system of the 21st aspect of the invention is the motor system of the 18th aspect, wherein the partition wall has a sealing mechanism with the housing at both ends.

Thereby, if the said partition has sealing mechanism (O-ring etc.) with the said housing in both ends, since the both ends of the said housing can be arrange | positioned outside air | atmosphere, the outer rotor of the said direct drive motor will be provided with respect to both ends of the said housing | casing. It can be supported by a bearing.

[Invention 22]

The motor system of the invention 22 is a motor system coaxially combining four or more direct drive motors used in an atmosphere outside the atmosphere,

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The outer rotor of one direct drive motor is supported by a bearing against one end of the housing, and the outer rotor of another direct drive motor is supported by a bearing against the other end of the housing. ,

The outer rotor of at least one direct drive motor is supported by a bearing with respect to each of the outer rotors of the two direct drive motors.

As a result, in a motor system in which four or more direct drive motors are coaxially coupled to each other in an atmosphere outside the atmosphere, each direct drive motor extends from the housing and the housing and partitions the atmosphere side and the atmosphere outside. And an outer rotor disposed outside the atmosphere with respect to the partition wall, a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting a rotational position of the inner rotor. Since the inner rotor rotates together with the outer rotor, the detector is placed inside the partition wall, thereby preventing the occlusion molecules of the wiring covering from contaminating the atmosphere outside the partition wall. In addition, the outer rotor of the direct drive motor is supported by bearings on both ends of the housing, and the outer rotor of another direct drive motor is supported by bearings on the outer rotor of each of the direct drive motors. Therefore, the same type of outer rotors connected by bearings can provide a motor system having high coaxiality with each other and a low mutual interference of mechanical precision with the same type of outer rotors coupled by bearings installed at the other housing end. have. Therefore, when applied to a biaxial coaxial leg arm robot, it is possible to increase the operation accuracy and increase the load.

[Invention 23]

The motor system of the twenty-third aspect of the invention is characterized in that, in the motor system of the twenty-second aspect, the end shape of any one of the housings is capable of detaching the outer rotors of all the direct drive motors in the axial direction.

As a result, one end shape of the housing supporting the partition structure allows the outer rotor of the direct drive motor to be removed in the axial direction, so that the outer rotors of all the direct drive motors can be removed from the partition wall. As a result, the inspection and detachment can be easily performed, thereby improving the maintainability. In addition, since only the outer rotor outside the partition wall needs to be removed, it is not necessary to remove the entire direct drive motor, and a leak check or the like is unnecessary at the time of reassembly, thereby improving assembly performance.

[Invention 24]

A motor system according to a twenty-fourth aspect of the invention is a motor system according to a twenty-second aspect, wherein the housing can be divided into units commonly used in two adjacent direct drive motors.

This is preferable because the housing can be divided into units commonly used in two adjacent direct drive motors because of excellent assembly performance and easy adjustment of phase matching between the motor and the detector.

[Invention 25]

The motor system of invention 25 is the motor system of invention 22, characterized in that the partition wall of one direct drive motor is common with the partition wall of another direct drive motor.

Thereby, since the partition of one direct drive motor is common with the partition of another direct drive motor, since the number of parts and a seal point can be reduced, it is preferable.

[Invention 26]

The motor system of the twenty-sixth aspect of the invention is the motor system of the twenty-second aspect of the present invention, wherein both ends of the partition wall have a sealing mechanism with the housing.

Thereby, if the said partition has sealing mechanism (O-ring etc.) with the said housing in both ends, since the both ends of the said housing can be arrange | positioned outside air | atmosphere, the outer rotor of the said direct drive motor will be provided with respect to both ends of the said housing | casing. It can be supported by a bearing.

[Invention 27]

The motor system of the present invention is a motor system in which a first direct drive motor and a second direct drive motor are coaxially coupled to each other in an atmosphere outside the atmosphere,

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The outer rotor of the second direct drive motor adjacent to the outer rotor of the first direct drive motor is supported via a second bearing,

The outer rotor of the first direct drive motor is supported via a first bearing by a bearing holder attached to the housing so as to be detachable from the housing.

As a result, in a motor system in which a first direct drive motor and a second direct drive motor which are used in an atmosphere outside the atmosphere are coaxially coupled, each direct drive motor extends from the housing and the housing, And a partition wall for extinguishing the outside of the atmosphere, an outer rotor disposed outside the atmosphere with respect to the partition wall, a stator disposed on the atmosphere side with respect to the partition wall, and a stator disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor It has an inner rotor and a detector for detecting the rotational position of the inner rotor, so that the detector is placed on the atmospheric side of the partition wall, so that the occlusion molecules of the wiring coating pollute the atmosphere outside the atmosphere of the partition wall Is prevented. In addition, the outer rotor of the second direct drive motor adjacent to the outer rotor of the first direct drive motor is supported via a second bearing, so that the outer rotor of the first direct drive motor The outer rotor is supported via a first bearing by a bearing holder attached to the housing so that the outer rotor can be detached from the housing so that the first direct drive motor is detached from the housing. It can be separated from, and the maintenance labor including inspection of the bearing attached to the bearing holder can be reduced.

[Invention 28]

The motor system of invention 28 is the motor system of invention 27, wherein the bearing holder is fixed to the housing by bolts, and the bolts are arranged outwardly from the outer rotor of the first direct drive motor. It features.

Thereby, if the said bearing holder is being fixed by the bolt with respect to the said housing, and the said bolt is arrange | positioned outside the said outer rotor of the said 1st direct drive motor, this outer rotor will not be removed and the said bolt will be removed. It is preferable because it can alleviate. In addition, "it arrange | positions outward from an outer rotor" means the state which does not interfere with a bolt or a tool and an outer rotor at least at the time of bolt detachment. Therefore, when the outer diameter of the outer rotor is non-circular, even if the bolt is inside the outer circumference depending on the rotational phase of the outer rotor, by rotating the outer rotor, when the bolt is outside the outer circumference, the bolt is outside It is assumed that it is disposed outside the rotor.

[Invention 29]

The motor system of invention 29 is the motor system of inventions 27 and 28, wherein the minimum inner diameter of the outer rotor of the first direct drive motor and the outer rotor of the second direct drive motor is greater than the maximum outer diameter of the partition wall. There is,

When the bearing holder is removed from the housing, the outer ring rotor of the first direct drive motor and the outer ring rotor of the second direct drive motor can be pulled out along the partition wall in the axial direction. It is characterized by being.

As a result, the minimum inner diameter of the outer rotor of the first direct drive motor and the outer rotor of the second direct drive motor is larger than the maximum outer diameter of the partition wall, and the bearing holder is removed from the housing. The outer ring rotor of the first direct drive motor and the outer ring rotor of the second direct drive motor can both be pulled out in the axial direction along the partition wall, so as to maintain both outer rings at the time of maintenance. It is preferable because the rotor can be disassembled integrally.

[Invention 30]

The motor system of the thirtieth invention is the motor system of the thirty-ninth invention, wherein the bolt for fixing the first bearing and the bearing holder is exposed when the bearing holder is removed from the housing.

As a result, when the bearing holder is removed from the housing, if the bolts fixing the first bearing and the bearing holder are exposed, such bolts can be relaxed, so that the first direct drive motor It is preferable because the outer rotor can be easily disassembled. Here, "exposed" means that the space which a tool can be hooked and a bolt can relieve generate | occur | produces.

[Invention 31]

The motor system of invention 31 is the motor system of invention 27, wherein the outer rotor of the second direct drive motor is formed by connecting a plurality of parts by bolts, and in the state where the motor system is assembled, By loosening the bolt connecting the plurality of parts, a part of the part can be removed, and the outer ring rotor of the second bearing and the first direct drive motor is fixed while the part of the part is removed. It is characterized in that the bolt is exposed.

Thereby, the said outer rotor of the said 2nd direct drive motor is made by connecting several components (for example, 2nd outer rotor 21b 'and cylindrical member 23' mentioned later) with a bolt, By loosening the bolt connecting the plurality of parts of the outer rotor with the motor system assembled, a part of the part (for example, the cylindrical member 23 ') can be removed and the part of the part When the bolts fixing the second bearing and the outer ring rotor of the first direct drive motor are exposed, the bolts can be relaxed, so that the outer rotor of the second direct drive motor is removed. It is preferable because it can be easily decomposed.

[Invention 32]

The motor system of the thirty-second aspect of the invention is the motor system of the thirty-first aspect, wherein in the motor system of the thirty-first aspect, the outer side of the second direct drive motor is relaxed by relaxing a bolt that fixes the outer ring rotor of the second bearing and the first direct drive motor. The remaining part of the rotor can be pulled out in the axial direction along the partition wall.

Thereby, the remaining parts in the said outer rotor of the said 2nd direct drive motor are alleviated by alleviating the bolt which fixes the outer bearing rotor of the said 2nd bearing and a said 1st direct drive motor (for example, For example, when the second outer rotor 21b ') can be pulled out in the axial direction along the partition wall, the outer rotor of the second direct drive motor can be easily disassembled.

[Invention 33]

The motor system of the thirty-third invention is the motor system according to any one of the twenty-seventh to twenty-third aspects, wherein each of the direct drive motors is common to the partition and the housing.

Thereby, in each direct drive motor, if the said partition is common with the said housing, the number of components can be reduced, and since the number of the sealing members sealing between members is also preferable, it is preferable.

[Invention 34]

The motor system of the thirty-fourth aspect of the present invention provides a motor system in which a plurality of direct drive motors are coaxially coupled to each other in an atmosphere outside the atmosphere.

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

The magnetic shield is arranged between at least one of the outer rotors, the inner rotors, and the stators in the adjacent direct drive motors.

As a result, in a direct drive motor used in an atmosphere outside the atmosphere, a housing, a partition wall extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition wall, It has a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting the rotational position of the inner rotor, the stator drives the outer rotor, and the inner rotor co-rotates with the outer rotor, By placing the detector inside the partition wall, it is prevented that the storage impurity molecules of the wiring covering contaminate the atmosphere outside the partition wall. In addition, since the magnetic shield is disposed between at least one of the outer rotors, the inner rotors, and the stators in the adjacent direct drive motors, leakage magnetic flux, electromagnetic noise, and the like generated from the rotor and the stator. Can be suppressed from affecting the rotor and the stator in the direct motor adjacent thereto. Therefore, the motor system can be thinned.

[Invention 35]

The motor system of the invention 35 is a motor system which coaxially combines a plurality of direct drive motors used in an atmosphere outside the atmosphere,

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

In addition, at least one of the outer rotors, the inner rotors, and the stators in the adjacent direct drive motors is characterized in that the number of magnetic poles is different from each other.

As a result, in a direct drive motor used in an atmosphere outside the atmosphere, a housing, a partition wall extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition wall, It has a stator and an inner rotor disposed on the atmosphere side with respect to the partition wall, and a detector for detecting the rotational position of the inner rotor, the stator drives the outer rotor, and the inner rotor co-rotates with the outer rotor, By placing the detector inside the partition wall, it is prevented that the storage impurity molecules of the wiring covering contaminate the atmosphere outside the partition wall. In addition, since at least one of the outer rotors, the inner rotors, and the stators in the adjacent direct drive motors has different magnetic poles from each other, leakage magnetic flux or electromagnetic noise generated from the rotor and the stator, The inconvenience of driving the rotor and the stator in the direct motor adjacent thereto can be suppressed. Therefore, the motor system can be thinned.

[Invention 36]

The motor system of the 36th invention is a motor system which coaxially combines a plurality of direct drive motors used in an atmosphere outside the atmosphere,

Each direct drive motor,

Housings,

A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere;

An outer rotor disposed outside the atmosphere with respect to the partition wall;

A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor;

It has a detector for detecting the rotation position of the inner rotor,

Moreover, the rotating wheel of the bearing apparatus which rotatably supports the said outer rotor is fitted to the rotor yoke, It is characterized by the above-mentioned.

Thereby, in a direct drive motor used in an atmosphere outside the atmosphere, a partition extending from the housing and separating the atmosphere side and the atmosphere outside, an outer rotor disposed outside the atmosphere relative to the partition wall, and the partition wall Has a stator and an inner rotor disposed on the standby side with respect to the air, and a detector for detecting a rotational position of the inner rotor, the stator drives the outer rotor, and the inner rotor co-rotates with the outer rotor. By placing the detector inside the partition wall, the storage impurity molecules of the wiring covering are prevented from contaminating the atmosphere outside the partition wall. In addition, the outer rotor and the rotating wheels of the bearing device rotatably supported are easy to achieve processing accuracy, and the linear expansion coefficient is fitted to the rotor yoke which is approximately the same as the drive wheels of the bearing device, thereby improving the rotational accuracy and changing the temperature. This can prevent the friction torque from fluctuating.

1 is a perspective view of a frog leg arm type conveying apparatus using the direct drive motor according to the present embodiment.

FIG. 2 is a view of the configuration of FIG. 1 taken along line II-II and viewed in the direction of the arrow. FIG.

3 is an exploded view showing the partition wall in the motor system according to the present embodiment.

4 is a diagram illustrating a resolver control circuit.

5 is a diagram illustrating a motor control circuit.

6 is a cross-sectional view showing the first modification of the present embodiment.

7 is a cross-sectional view showing a second modification of the present embodiment.

8 is a perspective view of a lock leg female conveying apparatus using the direct drive motor according to the present embodiment.

FIG. 9 is a view of the configuration of FIG. 8 taken along line II-II and viewed in the direction of the arrow. FIG.

FIG. 10 is a view of the configuration of FIG. 9 taken along line III-III and viewed in the direction of the arrow. FIG.

11 is a diagram illustrating a resolver control circuit.

12 is a diagram illustrating a motor control circuit.

13 is a diagram illustrating a modification of the present embodiment.

FIG. 14 is a sectional view similar to FIG. 9 of the direct drive motor according to the second embodiment which can be used for the conveying apparatus shown in FIG. 8.

15 is a schematic diagram showing a state in which eddy current damage occurs in the partition wall 113.

FIG. 16 is a schematic diagram as shown in FIG. 15 showing three magnets in a row direction.

Fig. 17 is a block diagram of the control system of the motor in the case where there is no partition.

18 is a control system block diagram of a motor in the case where a partition is present.

19 is a diagram illustrating the frequency characteristics of the transfer function G. FIG.

20 is a diagram illustrating frequency characteristics of the transfer function G. FIG.

21 is a diagram showing spring stiffness of magnetic coupling.

Fig. 22 is a perspective view of a lock leg female conveying apparatus using the direct drive motor according to the present embodiment.

FIG. 23 is a view of the configuration of FIG. 22 taken along line II-II and viewed in the direction of the arrow.

24 is a diagram illustrating a resolver control circuit.

25 is a diagram illustrating a motor control circuit.

It is sectional drawing which shows 2nd Embodiment.

27 is a cross-sectional view showing the third embodiment.

28 is a cross-sectional view showing the fourth embodiment.

Fig. 29 is a perspective view of a prog leg female transfer device using a motor system including a direct drive motor according to the present embodiment.

30 is a view, taken along the line II-II of FIG. 29 and viewed in the direction of the arrow.

31 is a diagram illustrating the resolver control circuit.

32 is a diagram illustrating a motor control circuit.

Fig. 34 is a perspective view of the flock leg female transfer device using the direct drive motor according to the present embodiment.

FIG. 35 is a view of the configuration of FIG. 34 taken along line II-II and viewed in the direction of the arrow. FIG.

36 is a diagram illustrating the resolver control circuit.

37 is a diagram illustrating a motor control circuit.

38 is a perspective view of a flock leg female transfer device using the direct drive motor according to the present embodiment.

FIG. 39 is a view of the configuration of FIG. 38 taken along line II-II and viewed in the direction of the arrow.

40 is a diagram illustrating the resolver control circuit.

41 is a diagram illustrating a motor control circuit.

42 is a perspective view showing a disassembly process of the motor system according to the present embodiment.

43 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

44 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

45 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

46 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

47 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

48 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

49 is a perspective view illustrating a disassembly process of the motor system according to the present embodiment.

50 is a diagram illustrating a modification of the present embodiment.

Fig. 51 is a perspective view of a lock leg female conveying apparatus using a direct drive motor according to a modification.

Fig. 52 is a perspective view of the flock leg female transfer device using the direct drive motor according to the present embodiment.

FIG. 53 is a view of the configuration of FIG. 52 taken along line II-II and viewed in the direction of the arrow.

54 is a diagram illustrating the resolver control circuit.

55 is a diagram illustrating the motor control circuit.

56 is a cross-sectional view showing a modification of the present embodiment.

※ Explanation of code ※

10... Disc 10... main body

101... Cover member 101... Inner rotor magnet for magnetic coupling

102... Magnetic shield plate 103. Magnetic shield plate

107... Bearing holder 108... Outer rotor magnet for coupling

109... Back yoke 10a... flange

11... Bolt 11... Small disc

11, 111... Bolt 110... Disc member

110... Upper disc portion 110... main body

110a... Flange 110b... Cylindrical attachment

111... Small disc 112... Stand disc

113... septum

113a... Bulkhead holder 113b... Thin cylinder

114... Four-point contact ball bearing 115... Inner holder

116... Outer rotor 117... Outer holder

118... Outer rotor magnet 19... Back york

12... Bulkhead 12. Stand disc

12... Body 12, 112... main body

121... Inner rotor 123... bearing

125... Back yoke 125... Magnetic shield plate

126... Detection rotor 127... Incremental resolver

128... Absolute resolver 129... Stator

12a... Flange portions 12a, 112a... Flange

12b... Outer periphery 12d... hole

12d... Guide hole 12e... Cutout

12e... Notation 13. septum

13, 113... Bulkheads 13, 113, 213, 313. septum

130... Magnetic shield plate 13a... Disc

13b... Cylindrical portion 14.. Four Point Contact Ball Bearing

15... Holder 15.. Inner ring holder

16... Bolt 16.. Outer rotor

17... Outer holders 17, 107... Bearing holder

17, 17 '... Bearing holder 18... Outer rotor magnet

18, 18 '... Bolt 19... Back york

19, 19 '... Four Point Contact Ball Bearing

19, 19 ', 119, 119'... Four Point Contact Ball Bearing

20... Stator holder 20, 20 '... volt

21... Inner rotor 21, 21 '... Outer rotor

21, 21 '... Outer rotor members 21, 21 ', 121, 121'... Outer rotor member

21a, 21a '... Permanent magnets 21b, 21b '... York

22... Resolver Holder 22, 22 '... volt

23... Cylindrical member 23... Ball bearing

23, 123... Cylindrical member 23 '... Ring shaped member

23 ', 123'... Ring shaped member

24... Inner rotor magnets 24, 24 '... volt

25... Back yoke 25, 25 '... Magnetic shield plate

26... Detection rotor 27... Incremental resolver

28... Absolute Resolver 29... Stator

29, 29 '... Stator 29, 29 ', 129, 129'... Stator

30... Magnetic shield plate 30, 30 '... Inner rotor

30, 30 ', 130, 130'... Inner rotor

30a, 30a '... Permanent magnets 30b, 30b '... Back york

32, 32 '... Resolver holder 32, 32 ', 132, 132'... Resolver holder

33, 33 '... Bearings 33, 33 ', 133, 133'... bearing

34, 34 '... Detection rotor 34a, 34a '... Incremental resolver rotor

34a, 34a ', 134a, 134a'... Incremental resolver rotor

34b, 34b '... Absolute resolver rotor

34b, 34b ', 134b, 134b'... Absolute resolver rotor

35, 35 '... Incremental resolver stator

35, 35 ', 135, 135'... Incremental resolver stator

36, 36 '... Absolute resolver stator

36, 36 ', 136, 136'... Absolute resolver stator

41... Magnetic shield plate

A1, A2... Arm A1, A2, A1 ', A2'... cancer

D1, D2... Direct drive motor

D1, D2, D3, D4... Direct drive motor

DMC1... Motor control circuit DMC2... Motor control circuit

G… Table HR… Resolver wiring

HS… Stator wiring L1, L2... link

L1, L2, L1 ', L2'... Link OR… O-ring

T… Table T, T '… table

[First embodiment]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view of a frog leg arm type conveying apparatus using the direct drive motor according to the present embodiment. In FIG. 1, two direct drive motors D1 and D2 are connected in series. The first arm A1 is connected to the rotor of the lower direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the upper direct drive motor D2, and the second link L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafer W is placed.

As apparent from Fig. 1, when the rotors of the direct drive motors D1 and D2 rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is the direct drive motor. (D1, D2) is approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches.

In this way, for example, in a device having a plurality of arms such as a wafer transport arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a flock leg type shown in the drawing, in particular, a plurality of rotary motors It becomes necessary. In a vacuum environment, it is necessary to make the contact surface area with the external world as small as possible, and to make the attachment holes such as a motor as small as possible in order to effectively utilize the space. Moreover, in order to convey the wafer W horizontally and to make the vibration small enough, it is necessary to firmly protect and hold the moment acting on the tip of the arm at the rotor support. Therefore, the direct drive motors D1 and D2 are coaxially connected in a plurality of housing parts, and the connecting parts are tightly joined by a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the space and housing where the motor rotor is installed. It is also necessary to space the outer space.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, in the case of arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized when the power is turned on, the arm A1 and A2 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber. The motor system which coaxially connects the direct drive motor which can satisfy such a requirement is demonstrated.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36 slot, has a small cogging force but generates a magnetic attraction force in the radial direction, so that vibration during rotation is four times larger than that of an 8-pole 9 slot slot combination. By setting it as 2 ⁿ times (n is an integer), since the magnetic attraction force in the radial direction is canceled, the vibration at the time of rotation can be reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts. As a result, the cogging is small, and thus a very smooth rotation can be obtained. On the other hand, by setting it as such a multipolar motor, since there are many electrical periods with respect to the period of a mechanical angle, positioning controllability is good. Therefore, it is very suitable for the direct drive motor which drives a robot apparatus without using a speed reducer like this invention. Moreover, since the thickness, the protrusion width | variety, and the yoke thickness of a rotor can be narrowed without lowering the total magnetic flux amount, it is suitable for the thin, large diameter, and narrow direct drive motor like this invention.

FIG. 2 is a view of the configuration of FIG. 1 taken along line II-II and viewed in the direction of the arrow. FIG. The internal structure of the two-axis motor system will be described in detail with reference to FIG. 2. First, the direct drive motor D1 will be described. The hollow cylindrical body 12, which is fitted to the central opening 10a of the disc 10 fixed to the surface plate G and fixed to each other by bolts 11, has a cup-shaped partition 13 attached to the upper end thereof. have. The center of the main body 12 can be used for passing through the wiring HS in the stator, the wiring HR in the resolver, and the like. The main body 12 and the disc 10 comprise a housing.

The partition 13 is made of stainless steel, which is a nonmagnetic material, and has a thick bottom portion 113a fitted to the main body 12, and a thin thickness extending through the direct drive motors D1 and D2 in the axial direction from its outer circumference. It consists of the cylindrical part 13b and the holder 15. Therefore, the partition 13 is commonly used for the direct drive motors D1 and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. By making the welded part of the cylindrical part 13b and the holder 15 into substantially the same thickness, it is suppressed that heat escapes only to the component in one side, and it is a structure which can weld a fitting part uniformly here. The joining surface of the holder 15 and the original plate 10 is grooved to insert the sealing member. After the sealing member OR is inserted into the groove, the holder 15 and the original plate 10 are bolted to each other. ), The fastening portions are separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the partition 13 and the holder 15 are hermetically bonded, and the holder 15 and the disc 10, and the disc 10 and the surface plate G are respectively sealed by an O-ring OR. . Therefore, it is hermetically sealed from the outside of the inner space surrounded by the disc 10 and the partition 13. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. Alternatively, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like instead of hermetically using the O-ring OR.

On the outer circumferential upper surface of the disc 10, the bearing holder 17 is fixed by the bolt 18. As shown in FIG. The outer ring of the four-point contact ball bearing 19 used in a vacuum is fitted to the bearing holder 17, and is fixed by the bolt 20. As shown in FIG. On the other hand, the inner ring of the bearing 19 is fitted to the outer circumference of the first outer rotor 21 and is fixed by the bolt 22. That is, the 1st outer rotor 21 is rotatably supported with respect to the partition 13, and the cylindrical member 23 which supports the arm A1 (FIG. 1) is fixed by the bolt 24. As shown in FIG. . The bolt 24 fixes the magnetic shield plate 25 extending radially inward to the cylindrical member 23 at the same time.

The disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance, and the disc 10 also serves as a fitting and sealing device with the base plate G, which is a chamber, and the bottom surface thereof. The groove 10b for fitting the O-ring OR is provided in the groove.

The magnetic shield plate 25 is nickel-plated in order to improve rust prevention and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The effect is mentioned later.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the two-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by hardening. The rolling element uses a ceramic ball and a lubricant grease for vacuum which does not solidify even in vacuum.

Further, the bearing 19 may be a metal lubrication without plating out of gas and silver by plating a soft metal such as gold or silver on the inner ring and the outer ring, and may be used as a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor 21 from A1) tilts can be received, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used, Alternatively, in order to improve lubricity, a fluorine-based coating treatment (DFO) may be performed.

The first outer rotor 21 mechanically fastens the permanent magnet 21a and the annular yoke 21b made of a magnetic body to form a magnetic path, and the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of nonmagnetic bodies for this purpose. The permanent magnet 21a is composed of 32 poles. The magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles, and are divided into segments, and each shape is linear. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge from the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetic properties, and nickel plating is applied to prevent corrosion and corrosion resistance after work forming and to prevent wear during bearing replacement.

Moreover, the 1st outer rotor 21 has the surface which fits and fixes the inner ring of the bearing 19, and the cylindrical member 23. As shown in FIG. The four-point contact ball bearing 19 is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the accuracy and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19, which is a rotating wheel, is easy to achieve the machining precision, and the gap is fitted to the yoke 21b having a linear expansion coefficient approximately equal to that of the track wheel material of the bearing without gaps or intermediate. By loosely fitting the outer ring of the bearing 19 which is a fixed wheel to the bearing holder made of austenitic stainless steel or the boss made of aluminum, the friction torque due to the decrease in the rotational accuracy of the bearing 19 or the temperature rise. It is a structure which prevents a raise.

In the radially inner side of the partition 13, the first stator 29 is disposed to face the inner circumferential surface of the first outer rotor 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the first stator 29 has a size substantially the same as or smaller than the inner diameter of the partition 13.

The first inner rotor 30 is disposed in the radially inner side of the first stator 29. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 that is bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the first inner rotor 30, a permanent magnet 30a is attached via a back yoke 30b. Like the permanent magnet 21a of the first outer rotor 21, the permanent magnet 30a has 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is a high energy neodymium (Nd-Fe-B) magnet, and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a and 34b are assembled on the inner circumference of the first inner rotor 30 as a detector for measuring the rotation angle, Although the resolver stators 35 and 36 are attached to the outer circumference of the resolver holder 32 in the form, in the present embodiment, the high resolution incremental resolver stator 35 and the position of the rotor at one rotation are determined. An absolute resolver stator 36 that can be detected is disposed on the second floor. Therefore, even when the power is turned on, the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known, so that the drive current of the direct drive motor D1 can be obtained. The rotation angle detection used for control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36, which are angle detectors. Later, chromate plating is performed for rust prevention.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and a rotation shaft is provided on the outer circumferential surface of the incremental resolver stator 35. In parallel with each other, a gear having a phase out of the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes, and the incremental resolver rotor 34a is rotated. Incremental resolver rotor by making the fundamental wave component of the magnetoresistance change to n cycles in one rotation of, detecting the magnetoresistance change, digitizing by the resolver control circuit illustrated in FIG. 4, and using it as a position signal. 34a), that is, the rotational angle (or rotational speed) of the first inner rotor 30 is detected. The detector is constituted by the resolver rotors 34a and 34b and the resolver stators 35 and 36.

According to this embodiment, since the 1st inner rotor 30 rotates at the same speed, ie, co-rotation, with respect to the 1st outer rotor 21, the 1st outer rotor 21 is rotated. Can be detected over the partition (13). In the present embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the eccentric adjustment and the position of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes or cutouts in the housing or both flanges. In addition, the rotating wheels of the bearing device 19 which rotatably supports the first outer rotor 21 are easy to achieve the machining precision, and the coefficient of linear expansion is applied to the rotor yoke 21b which is approximately the same as the drive wheel of the bearing device 19. By fitting, the rotational accuracy can be improved and frictional torque fluctuations can be prevented due to temperature change.

Next, although direct drive motor D2 is demonstrated, the main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and has the inner peripheral surface of the four-point contact ball bearing 19 'used for vacuum. The outer ring is fitted with a fitting and is fixed by the bolt 20 '. On the other hand, the inner ring of the bearing 19 'is fitted to the outer circumference of the second outer rotor 21' and is fixed by the bolt 22 '. The bolt 22 'and the magnetic shield plate 41 extending radially inward are simultaneously fixed. The second outer rotor 21 'is rotatably supported with respect to the partition wall 13, and the ring-shaped member 23' supporting the arm A2 (Fig. 1) is fixed by the bolt 24 '. Doing. In addition, the bolt 24 'fixes the magnetic shield plate 25' extending radially inward to the ring-shaped member 23 '.

The magnetic shield plates 41 and 25 'are nickel-plated in order to improve the rust prevention and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The magnetic shield plates 41 and 25 'form a magnetic shield between the first outer rotor 1 and the second outer rotor 21', and allow mutual rotation of each other by missing magnetic flux therefrom. It is preventing. That is, the magnetic shield plate 25 'is fastened to the yoke 21b' with the non-magnetic ring-shaped member 23 'interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated. Since the magnetic shield plates 41 and 25 'can prevent magnetic interference between the rotors, it is possible to configure a two-axis coaxial motor system with a reduced overall shaft length. The magnetic shield plate 41 prevents foreign material suction from the outside.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the two-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel which has high corrosion resistance and can be hardened by hardening. The rolling element uses a ceramic ball and a lubricant grease for vacuum which does not solidify even in vacuum.

Further, the bearing 19 'may be a plated soft metal such as gold or silver on the inner ring and the outer ring, and metal lubrication without outgassing may be used even in the case of vacuum, and since it is a four-point contact ball bearing, Although the moment in the direction in which the first outer rotor 21 'from the arm A1 is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross tapered bearing can be used, and a preload state Or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The second outer rotor 21 'mechanically fixes the permanent magnet 21' and the annular yoke 21b 'made of a magnetic body to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternation with each other, and are divided into segments and have a linear shape. The arc centers of the inner diameter and the outer diameter are the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a ', and the permanent magnet 21a' is screwed by screwing the wedge from the outer diameter side of the yoke 21b '. 21b '). With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel in order to increase corrosion resistance. The yoke 21b 'is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase the rust-prevention and corrosion resistance after work forming and to prevent wear during bearing replacement.

Moreover, the 2nd outer rotor 21 'has the surface which fits and fixes the inner ring of the bearing 19', and the ring-shaped member 23 '. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the precision and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19 'is easy to obtain the processing accuracy, and the linear expansion coefficient is fitted to the yoke 21b, which is approximately the same as the track wheel material of the bearing, without gaps or by intermediate fitting. The outer ring of the bearing 19 'is loosely fitted to an austenitic stainless steel bearing holder or an aluminum boss to reduce the rotational accuracy of the bearing 19' and increase the friction torque due to the temperature rise. It is made of a blocking structure.

In the radially inner side of the partition 13, the second stator 29 ′ is disposed to face the inner circumferential surface of the second outer rotor 21 ′. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. The motor coil is intensively wound after being inserted. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 30 'is disposed in the radially inner side of the second stator 29'. The second inner rotor 30 ′ is rotatably supported by the ball bearing 33 ′ against the resolver holder 32 ′ bolted to the outer circumferential surface of the main body 12. A permanent magnet 30a 'is attached to the outer circumferential surface of the second inner rotor 30' via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the first inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet 30a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34'a and 34b 'are assembled on the inner circumference of the second inner rotor 30' as a detector for measuring the rotational angle, and the stator is disposed on the outer circumference of the resolver holder 32 'in a form opposite thereto. (35 ', 36'), but in the present embodiment, a high resolution incremental resolver stator (35 ') and an absolute resolver stator (36) capable of detecting which of the dentures in one revolution are present. ') Is placed on the second floor. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b 'can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The relative rotation angle can be achieved without using a pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. The chromate plating is performed for rust prevention after work forming.

According to the present embodiment, the second inner rotor 30 'is rotated at the same speed, that is, accompanied by the magnetic coupling action, so that the second outer rotor 21' is rotated. The rotation angle of 21 'can be detected over the partition 13. In the present embodiment, the bearing 33 is formed by the resolver unit alone without using a part or a housing forming a motor. Therefore, the eccentric adjustment and the position of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes or cutouts in the housing or both flanges. In addition, the rotor wheel of the bearing device 19 'which rotatably supports the second outer rotor 21' is easy to achieve processing accuracy, and the rotor yoke (coefficient of linear expansion approximately equal to that of the drive wheel of the bearing device 19 ') 21b '), it is possible to improve the rotational accuracy and to prevent the frictional torque from fluctuating due to temperature change.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35'. The gears which are out of phase with respect to the incremental resolver rotor 34a 'at each magnetic pole are provided in parallel with the rotation axis, and the coil is wound for each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the second inner rotor 30', the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 'changes and the incremental resolver rotor In one rotation of 34a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 4, and used as a position signal. The rotational angle (or rotational speed) of the mental resolver rotor 34a ', that is, the second inner rotor 30' is detected. The detector is composed of resolver rotors 34a 'and 34b' and resolver stators 35 'and 36'.

According to the present embodiment, since the magnetic shield plates 25 and 41 are disposed between the first outer rotor 21 and the second outer rotor 21 ', mutual magnetic interference is suppressed, and The inconvenience of driving and accompanying rotation is avoided.

In the body 12 At least two guide holes 12d extending radially outward are formed so that the flange portion 12a extending between the direct drive motors D1 and D2 is radially penetrated, and the main body 12 is formed. The wiring HS inserted into the main body 12 from below is connected to the stators 29 and 29 'via the guide holes 12d. In this case, the inner rotors 30 and 30 'have an effect of electrostatic shielding.

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned inside the radial direction. On the other hand, at least one notch 12e, 12e is provided in the both ends of the main body 12, and it has a structure which draws the wiring HR in a resolver to the center of the main body 12 via these. By separating and treating the stator wiring HS and the resolver wiring HR well, it is possible to suppress the induction between the wirings.

3 is an exploded view of the lump in the motor system according to the present embodiment described above, but the outer rotor and the like are omitted. In the case of adjusting the resolver or the like, the partition 13 is removed from the original plate 10, and the main body 12 is removed from the original plate 10.

Here, in the direct drive motor D2, the resolver rotors 34a 'and 34b' and the resolver stators 35 'and 36' are adjusted by finely adjusting the phases of both gears. In the state, since the resolver rotors 34a 'and 34b' and the resolver stators 35 'and 36' are exposed on the upper side, they can be adjusted from the upper side. On the other hand, in the direct drive motor D1, since the resolver rotors 34a and 34b and the resolver stators 35 and 36 are exposed to the lower side, they can be adjusted from the lower side. After the adjustment, the main body 12 and the partition wall 13 are assembled again with the disc 10, and the outer rotor and the like which are other parts are assembled to bring the motor system into a movable state.

That is, according to the present embodiment, the second inner rotor 30 ', the second stator 29', the flange 12b, and the direct drive motor D1 of the direct drive motor D2 in order from the upper side in FIG. In order of the first stator 29, the first inner rotor 30, that is, the two inner rotors 30, 30 'sandwich the two stators 29, 29', Since it is arrange | positioned outside an axial direction, the resolver which opposes the inner rotors 30 and 30 'can be arrange | positioned outside an axial direction, respectively, and when matching these, it does not isolate | separate the direct drive motors D1 and D2. Since the adjustment work can be performed from both sides in the axial direction, the angles of the stator and resolver can be easily adjusted while being biaxial, and the adjustment work can be made more efficient. In addition, it is possible to prevent the deterioration of the angular positioning accuracy due to the commutation difference, and to improve the compatibility of the drive control circuit for the two-axis coaxial motor of the present invention. Configuration can be provided.

5 is a block diagram showing a drive circuit of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-phase amplifier from the CPU. The driving signal is output to the AMP, and the driving current is supplied from the three-phase amplifier AMP to the direct drive motors D1 and D2. As a result, the outer rotors 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1 and A2 (Fig. 1). When the outer rotors 21 and 21 'rotate, the resolver signals are output from the resolver stators 35, 36, 35', and 36 'that have detected the rotation angle as described above, so that they are converted to the resolver digital converter RDC. After the digital conversion, the input CPU determines whether the outer rotors 21 and 21 'have reached the command position, and when the command position reaches the command position, the outer rotor is stopped by stopping the drive signal from the three-phase amplifier AMP. The rotation of (21, 21 ') is stopped. This enables servo control of the outer rotors 21 and 21 '.

In the case of arm drive of a plurality of axes in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In this embodiment, a variable is composed of an absolute resolver stator (36 and 36 ') for detecting the absolute position of one rotation of the rotary shaft and an incremental resolver stator (35 and 35') for detecting a more precise rotational position. Since the magnetoresistive resolver is employed, the rotational position suppression of the outer rotors 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although a resolver is employed for rotation detection of the inner rotor 30 here, since the detector can be arranged on the atmospheric side of the partition 13, generally, a servo motor used for high-precision positioning is highly precise. An optical encoder adopted as a position detection means for smoothly driving, a magnetic encoder using a magnetoresistive element, or the like can also be used.

6 is a cross-sectional view showing a four-axis coaxial motor system according to a first modification of the present embodiment. In the modified example shown in FIG. 6, the direct drive motors D1 and D2 are arranged in two sets (four in total) directly, but the individual direct drive motors are the same as those shown in FIG. 2. Therefore, the same reference numerals are given to the main parts, and description thereof is omitted.

In the present embodiment, the annular concave portion 12h formed on the upper surface of one main body 12 is fitted with the annular convex portion 12k formed on the lower surface of the other main body 12. Two main bodies 12 are coaxially connected in series, and an upper disc member 110 is attached to an upper surface of the upper main body 12. The partition holder 113a is hermetically bonded to the upper disc member 110 via the O-ring OR, and the upper end of the thin cylinder 113b is welded to the outer circumferential surface thereof by TIG welding. The lower end of the thin cylinder 113b is TIG-welded to the holder 15 similarly to the above-mentioned embodiment. The partition wall is constituted by the partition holder 113a, the thin cylinder 113b, and the holder 15, but this is commonly used for four direct drive motors.

The upper surface of the disc member 110 is closed by the lid member 101, and the bearing holder 107 attached to the outer circumference thereof supports the bearing 19. The disc member 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.

The installation outer circumferential surface of the bearing holder 107 of the upper disc portion 110 is located radially inward in the thin cylindrical portion 113b, and thus, when the bearing holder 107 is removed from the upper disc portion 110, four The outer rotors 21 and 21 'can be detached to the upper side without disassembling the upper disc portion 110. Therefore, it is not necessary to disassemble the airtight structure at the time of maintenance and the like, and the operation can be facilitated.

In this embodiment, since the airtight shield plates 25 'and 25' are arrange | positioned with the 2nd outer rotor 21 'and 21' of the center, mutual magnetic interference is suppressed, and a misdrive and a companion are provided. Discomfort such as rotation is avoided. Moreover, between the main bodies 12 and 12, the airtight shield plate 125 extended radially from the outer periphery to the inner side of the thin cylindrical part 113b is arrange | positioned. The hermetic shield plate 125 is made of carbon steel, which is a magnetic material, and is interposed between the second stators 29 'and 29', so that the second outer rotors 21 'and 21' are affected by the leakage magnetic flux. It functions as an airtight shield that shields each other's magnetic fields so as not to generate thrust in the wrong rotational direction. In this manner, a configuration in which the entire axial length is suppressed while being four axes coaxial with the effects of the other airtight shields 25, 41 and 12b is possible. Moreover, between the main bodies 12 and 12, the extension member which is not shown in figure for extending the axial distance of a lower two axis | shaft (direct drive motor) and an upper two axis | shaft (direct drive motor) is provided, and a thin cylinder according to the thickness is provided. By extending the axial length of the part 113b, when the two coaxial prog leg female conveying apparatuses are comprised, the table T can be positioned near the outer diameter of the thin cylindrical part 113b, and the movable range becomes wider. Has the advantage.

In the present embodiment, it can be seen that the pair of direct drive motors D1 and D2 are combined up and down. Therefore, if the partition 13 is disassembled in order from the top in the drawing, the direct drive motors D1, Can be disassembled for each D2). In this case, the two inner rotors 30 and 30 'sandwich the two stators 29 and 29' and are arranged outside the axial direction. The resolver opposite to 30 ') can be disposed outside the axial direction, and in the case of adjusting them, adjustment can be performed on both sides of the axial direction without separating the direct drive motors D1 and D2. Even if it is more than an axis | shaft, angle adjustment of a stator and a resolver can be performed easily, and efficiency of adjustment operation can be aimed at. In addition, it is possible to prevent the deterioration of the angular positioning accuracy due to the commutation difference, and to improve the compatibility of the drive control circuit for the two-axis coaxial motor of the present invention. In addition, it is possible to provide a compact structure by suppressing the total height of the motor system. have. Moreover, although it is clear from the above, it is easy to form the motor system which combines 6-axis, 8-axis, 10-axis or more and direct drive motors D1 and D2 as long as space permits in this way.

7 is a cross-sectional view showing a four-axis coaxial motor system according to a second modification of the present embodiment. In the modified example shown in FIG. 7, the direct drive motors D1 and D2 are connected to each other via partition walls and arranged in pairs (four in total). However, the individual direct drive motors are shown in FIG. Since it is the same as the structure shown in 2, the same code | symbol is attached | subjected to a main component and description is abbreviate | omitted.

In this embodiment, the partition 13 is comprised from the holder 15, the partition holder 113a, and the thin cylindrical part 113b by which the one end was bent, and each is sealed by TIG welding. It is done in combination.

The main body 12 and the partition wall 13 fit the annular convex portions 113d formed on the atmospheric side of the partition holder 113a to the annular recesses 12h 'formed on the upper surface of one main body 12. And it is connected by the bolt 126 arrange | positioned at the atmospheric side of the o-ring 128.

In addition, the two main bodies 12 are coaxially connected in series via two partition holders 113a by bolts 127 arranged on the air side of the O-ring 128.

By adopting such a configuration, a finer tightening portion more finer than that of the first modification can be provided between the lower two axes (direct drive motor) and the upper two axes (direct drive motor). Therefore, in the case of configuring two coaxial prok leg female conveying apparatuses in which the table T, the links L1 and L2, and the arms A1 and A2 are attached to each of the lower two axes and the upper two axes, the table T ) Has the advantage that the positioning becomes possible near the outer diameter of the partition holder 113a, and the movable range is widened.

The upper surface of the disc member 110 is closed by the lid member 101 via the O-ring OR, and the bearing holder 107 attached to the outer circumference thereof supports the bearing 19. The disc member 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.

When the maintenance is performed, the lid member 101 and the bolt 127 are removed to separate the lower two shafts and the upper two shafts, and the airtight structure is disassembled. Since it is located in a small and easy to assemble point, there is a low possibility of causing airtight leakage.

Although the above embodiment has been described using an example using a surface magnet type 32 pole 36 slot out rotor brushless motor, the present invention is not limited to this type of motor and can be applied to a brushless motor. For example, it may be a permanent magnet embedded type, may be a different slot combination, or may be an inner rotor type.

As a countermeasure for each axis, the number of poles and the number of slots of the rotors of the axes adjacent to the axis direction may be different. For example, in the case of two-axis coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4-axis coaxials, the first and third axes are 32 poles 36 slots, the second axis. When the shaft and the fourth shaft have a configuration of 24 poles and 27 slots, mutual interference such as thrust generation in the rotational direction of the rotor and the magnetic coupling device due to the magnetic field of each shaft can be prevented .

In addition, the permanent magnet of the rotor is a neodymium (Nd-Fe-B) -based magnet, and as a coating for improving the corrosion resistance, it was described using an example in which nickel coating was applied. However, the material is not limited to this material and surface treatment. It is appropriately changed according to the environment, etc., for example, a samarium-cobalt (Sm · Co) -based magnet, which is difficult to be hot potato depending on the temperature conditions at the time of baking out, should be used. Titanium nitride coating with high gas barrier properties should be performed.

Although the yoke has been described using low carbon steel as a material and nickel plated, the material is not limited to the material and the surface treatment, and is appropriately changed according to the environment used. In particular, the surface treatment is ultra-vacuum. If it is to be used in the case that the pinhole is less carnigen plating, cleans plating, titanium nitride coating should be carried out.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed from the outer diameter side of the yoke. However, the permanent magnet is appropriately changed depending on the environment used, and may be appropriately bonded depending on the environment. It is good for method.

In addition, although the bearings 19 and 19 'demonstrated the example which used the four-point contact ball bearing for vacuum grease lubrication, it is not limited to this type, material, and lubrication method, According to the environment used, load conditions, rotation speed, etc. It may be changed appropriately, or may be a cross roller bearing. In the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, it may be a structure supported by a separate bearing. If not, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings, and when used in ultra vacuum, soft metals such as gold or silver may be used for the track wheels. Metal lubrication without gas release such as plating may be used.

In addition, although the inner rotor functioning as a magnetic coupling has been described in the form of using a permanent magnet and a back yoke, the materials and shapes of the permanent magnet and the back yoke are not limited thereto. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the outer rotor or may not be the same width. This can also be done with a permanent pole without a permanent magnet.

Moreover, although the example which used the resolver as an angle detector was demonstrated, it changes suitably according to manufacturing cost or resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33 and 33 'rotatably supporting the rotation side of an angle detector, it is not limited to this type and a lubrication method, If the multi-point contact bearing cannot be used, such as high speed rotation or lowering of friction torque, the angular bearing and the deep groove ball bearing are arranged in each axis to preload. Become .

In addition, the materials, shapes, and manufacturing methods of structural components and partitions arranged outside and inside other partitions are appropriately changed depending on manufacturing costs, the environment used, load conditions, and configurations.

The above-described motor system generates the thrust in the rotational direction to the magnetic coupling used in the rotor and rotation detection of each other by the magnetic flux leaking from the magnetic coupling used in the rotor, the rotor, and the resolver of each shaft. Magnetic shields for shielding each other's electromagnetic fields so as not to interfere with each other's resolvers by installing magnetic shields for shielding each other's magnetic fields between the rotors of each axis, or by electromagnetic fields generated from the rotors, stators, and resolvers of each axis. By installing the shield or changing the number of poles of the rotor and the number of slots of the stator between the axes adjacent to the axial direction, the magnetic interference occurring in each axis is prevented. Therefore, the axial length of each axis and the axis of each axis are prevented. The direction distance can be shortened. Therefore, the structure which restrained the whole axial length is possible, although it is a multi-axis coaxial motor system of 2 axis coaxial and 4 axis coaxial. In particular, in a system using a multi-axis direct drive motor called 4-axis coaxial, two prog leg arm robots can be installed that can be positioned with high precision without greatly changing the chamber structure, thereby increasing the performance and operation rate of the entire apparatus. Can be.

As mentioned above, although this invention was demonstrated with reference to embodiment, it should be understood that this invention is not limited to the said embodiment, Comprising: It is a matter of course that a change and deformation are possible suitably. For example, the direct drive motor of the present embodiment is not limited to the vacuum atmosphere, and can be used in an atmosphere outside the atmosphere. For example, in the case of a semiconductor manufacturing process, the reactive gas for etching may be introduce | transduced into a vacuum chamber after vacuum evacuation, but since the inside and the exterior are shielded by a partition in the direct drive motor of this embodiment, There is no possibility that a motor coil, an insulation material, etc. may be etched.

[2nd Embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. 8 is a perspective view of a lock leg female conveying apparatus using the direct drive motor according to the present embodiment. In FIG. 8, two direct drive motors D1 and D2 are connected in series. The first arm A1 is connected to the motor of the lower direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the motor of the upper direct drive motor D2, and the second link L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed.

As apparent from Fig. 8, when the rotors of the direct drive motors D1 and D2 rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is the direct drive motor. (D1, D2) is approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at an arbitrary angle, the wafer W can be conveyed at any two-dimensional position within the range where the table T touches.

In this way, for example, in a device having a plurality of arms such as a wafer carrier arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a prog leg type shown in the drawing, in particular, a plurality of rotary motors Is needed. In a vacuum environment, it is necessary to minimize the contact surface area with the outside world as much as possible and to make as small an attachment hole as possible for the motor or the like in order to effectively utilize the space. In addition, in order to convey the wafer W horizontally and with very small vibration, it is necessary to firmly protect and hold the moment acting on the tip of the arm at the rotor support. Therefore, the direct drive motors D1 and D2 are coaxially connected in plural and housing parts, and the connecting parts are tightly joined by a seal (tightly joined by welding, O-rings, metal gaskets, etc.) and the space where the motor rotor is installed. It is also necessary to space the outer space.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, during arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized when the power is turned on, the arms A1 and A2 may collide with the wall of the vacuum chamber or the shutter of the vacuum chamber. . A description will be given of a die drive motor capable of meeting these requirements.

FIG. 9 is a view of the configuration of FIG. 8 taken along line II-II and viewed in the direction of the arrow. FIG. FIG. 10 is a view of the configuration of FIG. 9 taken along line III-III and viewed in the direction of the arrow. FIG. The internal structure of the direct drive motor will be described with reference to FIGS. 9 and 10. In addition, since the basic structure of the direct drive motors D1 and D2 is the same, only the direct drive motor D1 will be described, and the description of the structure of the direct drive motor D2 will be omitted by the same reference numerals.

The hollow cylindrical body 10 in which the flange 10a is fixed to the surface plate G connects the small disk 11 to the upper end with a bolt. The large disk 12 is fixed to the upper surface of the small disk 11 by bolts (not shown). The center of the main body 10 can be used for making wiring through a stator. The housing is constituted by the main body 10, the small disc 11, and the large disc 12. On the upper surface of the large disc 12, a lid member 50 covering the opening of the main body 10 is bolted sealingly.

On the flange 10a of the main body 10, a cylindrical partition 13 made of stainless steel (SUS 304 or the like), which is a nonmagnetic material, is coaxially attached to the main body 10. The upper part of the partition 13 is thin, and the upper end is bent radially inward, and is attached in the form of being fitted to the small disk 11 by the disk 12. As shown in FIG. Moreover, the O-ring OR is arrange | positioned between each member of the direct drive motor D1 so that the flange 10a, the partition 13, and the small disc 11 of the main body 10 may be arranged. The enclosed internal space is hermetically sealed from the outside. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. Alternatively, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like instead of hermetically using the O-ring OR.

The inner ring of the four-point contact ball bearing 14 used in vacuum is fitted to the lower outer periphery of the partition 13, and the partition 13 is supported by the inner ring holder 15 which is bolted to the partition 13. Attached. On the other hand, the outer ring of the bearing 14 is fitted to the inner circumference of the outer rotor 16 and is attached to the outer rotor 16 by an outer holder 17 which is bolted to the outer rotor 16. That is, the outer rotor 16 is rotatably supported with respect to the partition 13. Bearing 14 is a plate made of metal lubrication with no outgassing in vacuum and plated with soft metals such as gold and silver on the inner and outer rings, and is a four-point contact ball bearing. Moment in the direction in which the outer rotor 16 from the tilt direction can be received, but not limited to the four-point contact type, cross rollers, cross balls, cross taper bearings can also be used, may be used in a preload state, and improved lubricity For this purpose, a fluorine-based coating treatment (DFO) may be performed.

An outer rotor magnet 18 is attached to the inner circumferential surface of the outer rotor 16. The outer rotor magnet 18 has a 24-pole configuration, and the magnets of the N pole and the S pole are made of magnetic metal in alternating twelve, and are assembled to the back yoke 19. The back yoke 19 may be made of magnetic stainless steel or nickel plated with iron. In the present embodiment, the outer rotor magnet 18 is formed by plating nickel on a magnet of neodymium iron boron. This outer rotor magnet 18 is fastened with a screw of a non-magnetic metal wedge against the outer rotor 16. Therefore, resins such as adhesives are not disposed, and even when the direct drive motor D1 is disposed in a vacuum, the discharge gas of the occlusion molecules can be extremely reduced. Moreover, the airtight shield plate 30 is attached to the outer rotor 16 so that the upper part of the outer rotor magnet 18 may be covered.

In the radially inner side of the partition 13, The stator 29 is arrange | positioned so that the inner peripheral surface of the outer rotor 16 may be opposed. The stator 29 is attached to the flange 10a of the main body 10 by the stator holder 20, and as shown in FIG. 10, each of the 12 phases in the order of U phase, V phase, and W phase in a cylindrical shape is shown. The coils are lined up, and thus, a total of 36 coils are included. This coil is molded from a mold material and integrated. Thus, since the stator 29 is arrange | positioned inside the partition 13, forced cooling, such as water cooling and air cooling, can be performed .

The inner rotor 21 is disposed in the radially inner side of the stator 29. The inner rotor 21 is rotatably supported by the ball bearing 23 with respect to the resolver holder 22 bolted to the outer circumferential surface of the main body 10. The inner rotor magnet 24 is attached to the outer circumferential surface of the inner rotor 21 via the back yoke 25. As with the outer rotor magnet 18, the inner rotor magnet 24 has a 24-pole configuration, and the magnets of the N pole and the S pole are made of magnetic metal in alternating angles of twelve, and are assembled to the back yoke 25. Therefore, the inner rotor 21 is rotationally driven by the stator 29 in synchronization with the outer rotor 16.

Although the detection rotor 26 for a detector which measures a rotation angle is assembled in the inner periphery of the inner rotor 21, the resolver 27 and 28 are attached to the outer periphery of the resolver holder 22 in the form which opposes it. In the present embodiment, the high resolution incremental resolver 27 and the absolute resolver 28 capable of detecting which position in one rotation are located on the second floor. Therefore, even when the power supply is turned on, the rotation angle of the detection rotor 26 can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known, so that the drive current of the direct drive motor D1 is controlled. Rotation angle detection used in the present invention can be performed without using a pole detection sensor.

In the high resolution variable magnetoresistive resolver used in the present embodiment, the detection rotor 26 has a plurality of slot teeth having a constant pitch, and is parallel to the rotation axis on the outer circumferential surface of the stator of the resolvers 27 and 28. In each stimulus, a gear having a phase out of the detection rotor 26 is provided, and a coil is wound around each stimulus. When the detection rotor 26 rotates integrally with the inner rotor 21, the magnetoresistance between the magnetic poles of the stator of the resolvers 27 and 28 changes, and the rotation of the magnetoresistance is changed by one rotation of the detection rotor 26. Rotation of the detection rotor 26, i.e., the inner rotor 21, by allowing the fundamental wave component to be n periods, detecting the change in magnetoresistance, digitizing it by the resolver control circuit illustrated in FIG. 11, and using it as a position signal. The angle (or rotational speed) is detected. The detector is constituted by the detection rotor 26 and the resolvers 27 and 28.

In the present embodiment, since the inner rotor 21 is driven to rotate in synchronization with the outer rotor 16 by the stator 29, if the rotation angle of the inner rotor 21 can be detected, therefrom. The angle of rotation of the outer rotor 16 can be immediately obtained, whereby driving control of the outer rotor 16 can be performed with high accuracy.

12 is a block diagram showing a drive circuit of the direct drive motor D1. When a rotation command is input from an external computer, the motor control circuit DMC outputs a drive signal from the CPU to the three-phase amplifier AMP, and the drive current from the three-phase amplifier AMP to the direct drive motor D1. Is supplied. As a result, the outer rotor 16 of the direct drive motor D1 rotates to move the arm A1. When the outer rotor 16 rotates, the resolver signal is output from the resolvers 27 and 28 that detect the rotation angle as described above. Therefore, the CPU input after digital conversion to the resolver digital converter RDC is the outer side. It is determined whether the rotor 16 has reached the command position, and when the command position is reached, the rotation of the outer rotor 16 is stopped by stopping the drive signal from the three-phase amplifier AMP. This enables servo control of the outer rotor 16.

In the present embodiment, since the absolute resolver 28 is used, the current flowing through the three-phase stator coil can be controlled according to the electric angle and the torque command of the detection rotor 26. If a current flows through the three-phase coils (U-phase, V-phase, W-phase) of the direct drive motor D1, it is a coreless motor structure, and according to the law of the left hand of Fleming, the outer rotor 16 and the inner rotor 21 Each will generate nearly identical torques. Originally, if the inner rotor 21 and the outer rotor 16 are not synchronized, they are supported by bearings free of rotation, respectively.

T _O : Generated torque at outer rotor 16

I _O : Inertia including load on the outer rotor 16 side

α _O : acceleration of outer rotor 16

T _I : Generated torque in the inner rotor 21

I _I : inertia of the inner rotor 21

α _I : acceleration of inner rotor 21

In this case, since the arm A1 is attached to the outer rotor 16, I _O : Since the inertia including the load on the outer rotor 16 side increases,

T _O = I _O × α _O

T _I = I _I × α _I

Try to rotate at different accelerations as

However, since the outer rotor 16 and the inner rotor 21 rotate in synchronization, a predetermined torque is generated by the displacement of the rotation angle. Therefore, the torque is transmitted from the inner rotor 21 to the outer rotor 16 in that the inner rotor 21 without the loading load advances in the direction in which the torque is generated with respect to the outer rotor 16. As a result, torque is transmitted so that the acceleration of the inner rotor 21 and the outer rotor 16 is the same, and the torque generated by the coil generates torque according to the inertia.

In the present embodiment described above, since the direct drive motor D1 supports the moment force by the multi-point contact bearing 14, the rigidity is high and the wafer W is horizontally conveyed evenly while the arm A1 is extended. can do. In addition Since the inner ring of the bearing 14 is assembled by the thickness member of the partition wall 13, since the acting force hardly acts on the partition wall 13 and is directly caught by the main body 10, the partition wall 13 is broken. The risk can be made extremely small.

Moreover, in the case of arm drive of multiple axes in a vacuum environment, if the current rotation position of the arm A1 is not recognized when the power is turned on, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber. In the embodiment, the variable magnetoresistive resolver composed of an absolute resolver 28 for detecting the absolute position of one rotation of the rotary shaft and an incremental resolver 27 for detecting the finer rotational position with a higher resolution is employed. Rotation position control of the rotor 16, that is, arm A1, can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 21 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

It is a figure which shows the modification of this embodiment. In the modified example shown in FIG. 13, the direct drive motors D1 and D2 are arranged in series (four in total), but the individual direct drive motors are the same as those shown in FIG. The same code | symbol is attached | subjected to a main component, and description is abbreviate | omitted.

Since the direct drive motor of this embodiment arrange | positions an inner rotor in the radial inside of a stator, since an axial dimension can be made small (thin), as shown in FIG. Moreover, a compact structure can be provided in the height direction. Further, because of the thin configuration, the rigidity can be increased to avoid the fear of resonance and the like, which is advantageous for multiaxialization and can reduce the difference in the control constants of the respective outer rotors. In addition, by stacking and using the same direct drive motor, in case of failure, only the direct drive motor needs to be replaced, which is excellent in maintainability and minimizes the inventory of the replacement parts.

FIG. 14 is a sectional view similar to FIG. 9 of the direct drive motor according to the second embodiment which can be used for the conveying apparatus shown in FIG. 8. FIG. In addition, since the direct drive motors D1 and D2 have the same basic configuration, only the direct drive motor D1 is described, and the configuration of the direct drive motor D2 is denoted by the same reference numerals, and description thereof is omitted.

In FIG. 14, the hollow cylindrical body 110 which fixed the flange 110a to the surface plate G is connected with the small disk 111 by the bolt at the upper end. On the outer circumferential side of the upper surface of the small disk 111, the large disk 112 is fixed by a bolt (not shown). The center of the main body 110 can be used in order to communicate with wiring to the stator. The housing is constituted by the main body 110, the small disc 111, and the large disc 112.

The lower end is press-fitted to the cylindrical attachment part 110b formed on the flange 110a of the main body 110, and the cylindrical partition 113 made of stainless steel (SUS 316L etc.) which is a nonmagnetic material is provided with respect to the main body 110. FIG. It is mounted coaxially. The upper part of the partition 113 is thin, and the upper end is bent radially inward, and is attached in the form which is simultaneously fixed to the small disk 111 by the disk 112. As shown in FIG. Moreover, the O-ring OR is arrange | positioned between each member of the direct drive motor D1 so that the flange 110a, the partition 113, and the small disc 111 of the main body 110 may be arranged. The enclosed interior space is hermetically sealed from the outside. In addition, the partition wall 113 does not necessarily need to be a nonmagnetic material. Alternatively, instead of hermetically using the O-ring OR, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like.

The inner wall of the four-point contact ball bearing 114 used in vacuum is fitted to the lower outer periphery of the partition 113, and the partition 113 is formed by the inner ring holder 115 which is bolted to the partition 113. It is attached to. On the other hand, the outer ring of the bearing 114 is fitted to the outer circumference of the outer rotor 116 by an outer holder 117 fitted to the inner circumference of the outer rotor 116 and bolted to the outer rotor 116. That is, the outer rotor 116 is rotatably supported with respect to the partition wall 113. The bearing 114 uses a metal lubrication plated with a soft metal such as gold or silver on the inner ring and the outer ring, and has no outgassing during vacuum, and is a four-point contact ball bearing. Moment in the direction in which the outer rotor 116 tilts from, but not limited to four-point contact, cross rollers, cross balls, cross taper bearings can also be used, may be used in a preload state, lubricity In order to improve, you may perform a fluorine-type coating process (DFO).

The outer rotor magnet 108 for magnetic coupling is attached to the center of the inner circumferential surface of the outer rotor 116. The outer rotor magnet 108 for magnetic coupling has a 32-pole configuration, and is made of a magnetic metal in which 16 magnets of N pole and S pole are alternately arranged, and are assembled to the back yoke 109. The back yoke 109, which is a rotor for magnetic coupling fitted to the outer rotor 116, may be magnetically stainless or nickel plated with iron. In this embodiment, the outer rotor magnet 108 for magnetic coupling uses the nickel plated thing with the magnet of neodymium iron boron. Moreover, the said outer rotor magnet 108 for magnetic coupling fastens the non-magnetic metal wedge against the outer rotor 116 with a screw. Therefore, even if resin, such as an adhesive agent, is not arrange | positioned, even when the direct drive motor D1 is arrange | positioned in a vacuum, the emission gas of occluded impurity molecule | numerator can be made extremely small. The magnetic shield plate 103 is attached to the outer rotor 116 so as to cover the upper portion of the outer rotor magnet 108 for magnetic coupling.

In addition, an outer rotor magnet 118 is attached to an upper portion of the inner circumferential surface of the outer rotor 116. The outer rotor magnet 118 is made of magnetic metal in which the magnets of the N pole and the S pole are alternately arranged in each of 32 poles, and are assembled to the back yoke 119. The back yoke 119 may be made of magnetic stainless steel or nickel plated with iron. In this embodiment, the outer rotor magnet 118 is nickel plated with a neodymium iron boron magnet. Moreover, the said outer rotor magnet 118 is fastening the wedge of a nonmagnetic metal with respect to the outer rotor 116 with a screw. Therefore, even if resin, such as an adhesive agent, is not arrange | positioned, even when the direct drive motor D1 is arrange | positioned in a vacuum, the emission gas of occluded impurity molecule | numerator can be made extremely small. The upper portion of the outer rotor magnet 118 is covered, and a magnetic shield plate 130 is attached to the lower surface of the disc 112.

In the radially inner side of the partition wall 113, the stator 129 is disposed to face the outer rotor magnet 118. The stator 129 is attached to the main body 110. Although not shown in the drawing, three coils of U slots, three slots of V phases, and three slots of W phases are arranged in four pairs of coils, that is, 36 slots in total. Is done. The magnetic shield plate 102 is attached to the outer rotor 116 so as to cover the top of the stator 129.

Since the 32-pole 36-slot motor has a slot structure four times larger than that of a conventional motor with a low cogging force of 8-pole 9 slots, similarly, a low cogging force can be realized. Moreover, since it is the structure of the even number of the 8-pole 9-slot motor, in-phase and the same pole are arrange | positioned at the diagonal of the outer rotor 116. As shown in FIG. In an 8-pole 9-slot motor, the unbalance of the magnet attraction force may generate a radial force in the bearing to support, and vibration may occur due to the rigidity of the bearing 114, but the unbalanced force is diagonal. Since it is canceled by the in-phase copper pole of the phase, the bearing 114 which supports the outer rotor 116 does not act, but has a characteristic which suppressed the generation | occurrence | production of a vibration.

Moreover, in the radially inner side of the partition 113, the inner rotor magnet 101 for magnetic coupling is arrange | positioned so that it may oppose the outer rotor magnet 108 for magnetic coupling. The inner rotor magnet 101 for magnetic coupling is connected to the inner rotor 121 rotatably supported via the bearing 123 with respect to the cylindrical attachment portion 110b of the flange 110a of the main body 110. It is attached via 125). The inner rotor magnet 101 for magnetic coupling has a configuration of 32 poles similarly to the outer rotor magnet 108 for coupling, and the magnets of the N pole and the S pole are alternately arranged in each of 16 pieces. Therefore, the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet 108 for magnetic coupling are fixed relative rotation by magnetic force pulling each other with the other pole facing each other via the partition 113, that is, both The inner rotor 121 rotates in synchronization with the back yoke 119, i.e., the outer rotor 116, based on the magnetic coupling force acting in a non-contact manner on the space.

Although the detection rotor 126 for a detector which measures a rotation angle is assembled in the inner periphery of the inner rotor 121, the resolver 127, 128 is attached to the outer periphery of the main body 110 in the form which opposes it. In this embodiment, a high resolution incremental resolver 127 and an absolute resolver 128 capable of detecting which position in one rotation are located on the second floor. For this reason, even when the power supply is turned on, the rotation angle of the detection rotor 126 can be known, the zero point return is not necessary, and the electrical phase angle of the magnet with respect to the coil can be known, so that the drive current of the direct drive motor D1. The rotation angle detection used for control is enabled without using a pole detection sensor.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the detection rotor 126 has a plurality of slot teeth having a constant pitch, and the magnetic pole outer peripheral surfaces of the resolvers 127 and 128 are parallel to the rotation axis. In each magnetic pole, a gear having a phase out of the detection rotor 126 is provided, and a coil is wound around each magnetic pole. When the detection rotor 126 rotates integrally with the inner rotor 121, the magnetoresistance between the magnetic poles of the stator of the resolvers 127 and 128 changes, and the rotation of the magnetoresistance is changed by one rotation of the detection rotor 126. Rotation of the detection rotor 126, i.e., the inner rotor 121, by allowing the fundamental wave component to have n periods, detecting the change in magnetoresistance, digitizing it by the resolver control circuit illustrated in FIG. 11, and using it as a position signal. The angle (or rotational speed) is detected. The detector is constituted by the detection rotor 126 and the resolvers 127 and 128.

In the present embodiment, since the inner rotor 121 is driven to rotate in synchronization with the outer rotor 116 via the magnetic coupling, if the rotation angle of the inner rotor 121 can be detected, and immediately the outer rotor ( The angle of rotation of 116 can be obtained. Moreover, the direct drive motor D1 of this embodiment is servo controlled by the drive circuit as shown in FIG.

In the present embodiment, the magnetic shield plates 102 and 103 have a magnetic field generated between the stator 129 and the outer rotor magnet 118, and the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet for magnetic coupling. It is provided so as to disturb the suction force between the 108 and not affect the magnetic coupling action. However, since the magnetic poles of the stator 129 and the outer rotor magnet 118 are 32 poles, the magnetic poles of the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet 108 for magnetic coupling are also 32 poles. Because of the number, even if the magnetic shield plates 102 and 103 are omitted, the suction force between the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet 108 for magnetic coupling is not particularly disturbed. Therefore, the magnetic shield plates 102 and 103 are used when the magnetic poles of the stator 129 and the outer rotor magnet 118 are different from the magnetic poles of the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet 108 for magnetic coupling. Especially valid.

However, when the outer rotor 116 vibrates by the action of the magnetic coupling, the inner rotor 121 also vibrates accordingly, and the resolvers 127 and 128 detect the angular position based on the direct drive motor D1. ), The rotational motion of the outer rotor 116 may be abnormal. This is called resonance of the magnetic coupling system. In this embodiment, the partition wall 113 is used to avoid such an operation abnormality.

The principle of reducing the gain peak value of the resonance frequency of the magnetic coupling system using the eddy current damage of the partition 113 is shown below. 15 is a schematic diagram showing a state in which eddy current damage occurs in the partition wall 113. In Fig. 15, the outer rotor 116 is attached with an N pole of the outer rotor magnet 108 for magnetic coupling, and the inner rotor 121 is attached with an S pole of the inner rotor magnet 101 for magnetic coupling. It is assumed that the silver partitions face each other with the partition wall 113 therebetween to form a magnetic coupling.

Here, in FIG. 15, when a predetermined electric power is supplied to a stator not shown, the outer rotor 116 rotates in the direction of the arrow in the drawing, but the inner rotor is caused by a magnetic coupling action based on the magnetic force passing through the partition wall 113. Reference numeral 121 also rotates in the same direction. At this time, the eddy current A generate | occur | produces in the a side (the side which magnetic flux density increases) of the partition 113 in the direction which weakens a magnetic flux. On the b side of the partition 113 (the side where the magnetic flux density decreases), an eddy current B of reverse rotation is generated in the direction of increasing the magnetic flux. This is the principle of eddy currents in which a current is generated so as to prevent a change in magnetic flux.

FIG. 16 is a schematic diagram as shown in FIG. 15 showing three magnets in a column direction, and shows a state in which a brake force for rotation is generated using an eddy current. When the outer rotor 116 rotates relatively in the direction indicated by the arrows in FIG. 16, eddy currents are generated in the partition wall 113 by the principle shown in FIG. 15 to generate magnetic flux. The magnetic flux generated by the eddy current generates a repulsive force with respect to the traveling direction of the magnet 108 provided in the outer rotor 116. Since the eddy current increases as the rate of change of the magnetic flux increases, the higher the magnetic permeability (透 磁 率, magnetic resistance) of the partition wall 113 and the magnetic flux density and frequency of the magnet 108 become. The partition 113 has an intrinsic magnetoresistance value and an electrical resistance value from its material and shape, and the product of the square of the electrical resistance value and the eddy current becomes the eddy current damage of the partition wall 113. Therefore, due to the eddy current damage of the partition wall 113 depending on the frequency, the dumping resistance of the outer rotor 116 is generated during the magnetic coupling action, for example, when the outer rotor 116 vibrates, this is attenuated. It has an effect.

Fig. 17 is a block diagram of the control system of the motor when there is no partition, and Fig. 18 is a block diagram of the control system of the motor when the partition is present. When there is no partition 113, as shown in FIG. 17, the outer rotor 116 receives reaction force only by the spring stiffness Kf of a magnetic coupling, and when there exists a partition 113, it shows in FIG. As can be seen, it is seen that the reaction force is received based on the spring stiffness Kf of the magnetic coupling and the dumping resistance Cf of the partition wall.

Here, in the control system shown in Fig. 18, the transfer function of the motor speed ωrm with respect to the motor torque Te becomes as shown in equation (1), and the resonance frequency and attenuation rate are expressed by equations (2), (3), It becomes as (4), (5). Where Jm is motor inertia, Jr is resolver inertia, Kf is spring coefficient of magnetic coupling, Cf is dumping resistance of magnetic coupling, ωa is resonance frequency, ωz is anti-resonant frequency, ξ _a , ξ _z is Attenuation rate.

The frequency characteristics of this transfer function G are shown in FIG. 19, FIG. Gain is only have a large peak at the resonance point (ωat), this is _a damping factor ξ: When the smaller (or Cf dumping resistance due to eddy current loss), the higher becomes smaller. In other words, it is understood that the smaller the eddy current loss with respect to the frequency, the larger the gain peak value of resonance becomes. If the resonance is large, the phase of the angle detection signal of the resolver and the phase of the outer rotor may be reversed, thereby causing the direct drive motor to oscillate. Not in order to avoid this well by increasing the damping factor ξ _a, in this case, it is possible to reduce the peak value by increasing the dump resistance consisting of an eddy current loss of the partition walls. In the past, oscillation has been prevented by using an angle signal using a notch filter for this resonance frequency in a motor control unit. However, if the characteristics of the notch filter are too strong, there is a possibility that the angle signal near the resonance frequency cannot be controlled. On the other hand, by using the eddy current damage of a partition, the peak value of a resonance frequency can be made small, and the vicinity of a resonance frequency can also be controlled. In addition, the spring stiffness of the magnetic coupling is shown in FIG.

The biaxial coaxial direct drive motor according to the present invention utilizes the eddy current loss of the partition wall, thereby making it possible to reduce the peak of the gain of the resonance frequency of the magnetic coupling. However, since the eddy current damage is connected to the heat generation of the partition wall, it is preferable to determine the material and shape of the partition wall in consideration of the heat generation. In addition, by determining the dumping resistance together with the effect of the weak notch filter, the heat generation is small and the control can be made possible.

As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is limited to the said embodiment and should not be interpreted, Of course, it can change and improve suitably. For example, the direct drive motor of this embodiment is not limited to a vacuum atmosphere, but can be used in an atmosphere outside the atmosphere. For example, in the semiconductor manufacturing process, the reactive gas for etching may be introduced into the vacuum chamber after vacuum evacuation, but in the direct drive motor of the present embodiment, since the inside and the outside are shielded by the partition wall, There is no possibility that a motor coil, an insulation material, etc. may be etched.

[Third embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. 22 is a perspective view of a frog leg female conveying apparatus using the direct drive motor according to the present embodiment. In Fig. 22, two direct drive motors D1 and D2 are connected in series. The first arm A1 is connected to the rotor of the lower direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the upper direct drive motor D2, and the second link L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed.

As apparent from Fig. 22, when the rotors of the direct drive motors D1 and D2 rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is a direct drive. The motors D1 and D2 are approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches.

In this way, for example, in a device having a plurality of arms, such as a wafer transfer arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a frog leg type shown in the drawing, a plurality of types are particularly preferable. Of rotation motor is required. In a vacuum environment, it is necessary to make the contact surface area with the outside world as small as possible, and in order to utilize the space effectively, the attachment holes of the motor and the like should be as small as possible. In addition, in order to convey the wafer W horizontally straight with the least vibration, it is necessary to firmly protect and maintain the moment acting on the tip of the arm at the rotor support. Therefore, the direct drive motors D1 and D2 are coaxially connected in a plurality of housing parts, and the connection parts are tightly joined (tightly joined by welding, O-ring, metal gasket, etc.) with a seal, and the motor rotor is installed. It is also necessary to separate the space from the space outside the housing.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, in the case of arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized at the time of power supply, the arms A1 and A2 may hit the walls of the vacuum chamber or the shutter of the vacuum chamber. A motor system that coaxially connects a direct drive motor capable of meeting these demands will be described.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36-slot, is four times the combination of 8-pole 9-slot and 7-slot combinations, which are generally known to have a small cogging force but generate magnetic attraction in the radial direction and a large vibration during rotation. Since the magnetic attraction force in the radial direction is canceled by setting it to 2 ⁿ times (n is an integer), the vibration at the time of rotation is reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts. In addition, since cogging is inherently small in structure, very smooth rotation can be obtained. On the other hand, as such a motor having many poles, since the period of the electric angle with respect to the period of the machine angle is large, the positioning controllability is good. Therefore, it is very suitable for the direct drive motor which drives a robot apparatus without using a speed reducer like this invention. In addition, since the thickness, protrusion width, and yoke thickness of the rotor can be narrowed without lowering the total amount of magnetic flux, it is very suitable for a thin, large diameter and narrow direct drive motor, as in the present invention.

FIG. 23 is a view of the configuration of FIG. 22 taken along line II-II and viewed in the direction of the arrow. With reference to FIG. 23, the internal structure of a two-axis motor system is demonstrated in detail. First, the direct drive motor D1 will be described. The hollow cylindrical body 12 fitted to the central opening 10a of the disc 10 fixed to the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition 13 attached to the upper end thereof. Doing. The center of the main body 12 can be used in order to communicate with wiring to the stator. The main body 12 and the disc 10 comprise a housing.

The partition 13 is made of stainless steel, which is a nonmagnetic material, and has a thick bottom portion 13a fitted to the main body 12, and a disc portion extending through the direct drive motors D1 and D2 in the axial direction from its outer circumference ( It consists of a cylindrical part (cylindrical part, 13b) thinner than 13a). Therefore, the partition 13 is commonly used for the direct drive motors D1 and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. Here, the welding part between the cylindrical part 13b and the holder 15 is made to be substantially the same thickness, and it is the structure which can suppress that a heat | fever escapes only to the component to one side, and can weld a fitting part uniformly. The contact surface of the holder 15 and the disc 10 is grooved to fit the seal member, and the holder 15 and the disc 10 are fastened by the bolt 16 after the seal member is inserted into the groove. As a result, the fastening portion is separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the main body 12 and the partition wall 13, and the partition wall 13 and the holder 15 are hermetically bonded, and the holder 15, the disc 10, the disc 10 and the surface plate G are Each is sealed by an O ring. Therefore, the inner space surrounded by the original plate 10, the main body 12, and the partition wall 13 is hermetically sealed from the outside thereof. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. Alternatively, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like instead of hermetically using the O-ring OR.

On the outer circumferential upper surface of the disc 10, the bearing holder 17 is fixed by the bolt 18. As shown in FIG. The outer ring of the four-point contact ball bearing 19 used in a vacuum is fitted to the bearing holder 17, and is fixed by the bolt 20. As shown in FIG. On the other hand, the inner ring of the bearing 19 is fitted to the outer circumference of the first outer rotor 21 and is fixed by the bolt 22. That is, the 1st outer rotor 21 is rotatably supported with respect to the partition 13, and the cylindrical member 23 which supports the arm A1 (FIG. 22) is fixed by the bolt 24. As shown in FIG. Here, the bolt 24 simultaneously fixes the magnetic shield plate 25 extending radially inwardly to the cylindrical member 23.

The disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance, and the disc 10 also serves as a fitting and sealing device with the base plate G, which is a chamber, and the bottom surface thereof. The groove 10b which fits the O-ring OR is provided in this.

The magnetic shield plate 25 is nickel-plated in order to improve antirust and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The effect is mentioned later.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the two-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify in vacuum. Doing.

In addition, the bearing 19 may use a metal lubrication which plated a soft metal such as gold or silver on the inner ring and the outer ring, and has no outgassing even in vacuum, and is a four-point contact ball bearing. Although the first outer rotor 21 from (A1) can receive the moment in the direction to tilt, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used, and are used in the preload state. In order to improve lubricity, a fluorine-based coating treatment (DFO) may be performed.

The first outer rotor 21 is a permanent magnet 21a, a ring-shaped yoke 21b made of magnetic material to form a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of these. The permanent magnet 21a is composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternating manner, and are divided into poles, and the individual shapes thereof are linear. to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge at the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is a neodymium (Nd-Fe-B) magnet having high energy [(BH) max] and is coated with nickel in order to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase the rust prevention and corrosion resistance after work forming and to prevent wear during bearing replacement.

Moreover, the 1st outer rotor 21 has the surface which fits and fixes the inner ring of the bearing 19, and the cylindrical member 23. As shown in FIG. The four-point contact ball bearing 19 is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the accuracy and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19, which is a rotating wheel, can easily be processed, and the gap between the inner ring of the bearing 19 can be easily fitted to the yoke 21b of which the coefficient of linear expansion is approximately the same as that of the track wheel of the bearing, And loosely fitting the outer ring of the bearing 19, which is a fixed wheel, to the bearing holder made of austenitic stainless steel or the boss made of aluminum, thereby increasing the friction torque due to the decrease in the rotational accuracy of the bearing 19 or the temperature rise. It is configured to prevent this.

In the radially inner side of the partition 13, the first stator 29 is disposed to face the inner circumferential surface of the first outer rotor 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, and is formed of a laminated material of an electromagnetic steel sheet, and is provided as an insulating treatment on each protrusion. After the bobbin is inserted, the motor coil is concentrated. The outer diameter of the first stator 29 is approximately equal to or smaller than the inner diameter of the partition 13.

The first inner rotor 30 is disposed radially inward of the first stator 29. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 which is bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the first inner rotor 30, a permanent magnet 30a is attached via a back yoke 30b. Like the permanent magnet 21a of the first outer rotor 21, the permanent magnet 30a is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a and 34b are assembled on the inner circumference of the first inner rotor 30 as detectors for measuring the rotation angle, and in the form opposite to the resolver holder 32, the resolver stators 35 and 36. In this embodiment, the high resolution incremental resolver stator 35 and the absolute resolver stator 36 capable of detecting which position of the rotor are located on the second floor are arranged in the second layer. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The rotation angle detection used for drive current control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36 which are angle detectors. Later, chromate plating is performed for rust prevention.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and the rotation axis and the outer peripheral surface of the incremental resolver stator 35 In parallel, a gear having a phase out of the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes, and the incremental resolver rotor 34a Incremental resolver rotor by making the fundamental wave component of the magnetoresistance change in n cycles by one rotation of the signal, detecting the magnetoresistance change, digitizing by the resolver control circuit illustrated in FIG. 34a), that is, the rotation angle (or rotation speed) of the first inner rotor 30 is detected. The detector is constituted by the resolver rotors 34a and 34b and the resolver stators 35 and 36.

According to the present embodiment, the first inner rotor 30 rotates at the same speed with the magnetic coupling action, that is, the co-rotation with respect to the first outer rotor 21, thereby rotating the first outer rotor 21. The angle can be detected over the partition 13. In the present embodiment, the resolver unit has a bearing 33 without using a component or a housing forming a motor. Therefore, the eccentric adjustment, the position adjustment of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes or cutouts in the housing or both flanges.

Next, although the direct drive motor D2 is demonstrated, the main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and has the inner peripheral surface of the four-point contact ball bearing 19 'used for vacuum. The outer ring is fitted with a fitting and is fixed by the bolt 20 '. On the other hand, the inner ring of the bearing 19 'is fitted to the outer circumference of the second outer rotor 21' and is fixed by the bolt 22 '. Here, the bolt 22 'and the magnetic shield plate 41 extending inward in the radial direction are simultaneously fixed. The second outer rotor 21 'is rotatably supported with respect to the partition wall 13, and the ring-shaped member 23' supporting the arm A2 (Fig. 22) is fixed by the bolt 24 '. have. In addition, the bolt 24 'fixes the magnetic shield plate 25' extending radially inward to the ring-shaped member 23 '.

The magnetic shield plates 41 and 25 'are nickel-plated in order to improve the rust prevention and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The magnetic shield plates 41 and 25 'form a magnetic shield between the first outer rotor 21 and the second outer rotor 21', and mutually rotate together by missing magnetic flux therefrom. Is preventing. That is, the magnetic shield plate 25 'is fastened to the yoke 21b' with the non-magnetic ring-shaped member 23 'interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated. Since the magnetic shield plates 41 and 25 'can prevent magnetic interference between the rotors, it is possible to have a structure in which the entire shaft length is reduced while being a two-axis coaxial motor system. The magnetic shield plate 41 prevents foreign material suction from the outside.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the two-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

The bearing 19 'may be made by plating a soft metal such as gold or silver on the inner ring and the outer ring, and using metal lubrication with no outgassing during vacuum. Since it is a contact ball bearing, the moment in the direction in which the first outer rotor 21 'from the arm A1 tilts can be received, but not only the four-point contact type but also the cross roller, cross ball, and cross taper bearing It may be used, may be used in a preload state, or may be subjected to fluorine-based coating treatment (DFO) for improving lubricity.

The second outer rotor 21 'mechanically fixes the permanent magnet 21a', a ring-shaped yoke 21b 'made of a magnetic body to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles. The permanent magnet 21a' is divided into poles, and the individual shapes thereof are linear. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential section is directed toward the permanent magnet 21a ', and the permanent magnet 21a' is yoked by screwing the wedge at the outer diameter side of the yoke 21b '. It is fastened to 21b '. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel in order to increase corrosion resistance. The yoke 21b 'is made of a low-carbon steel having high magnetic properties, and nickel plating is applied to prevent rust and corrosion resistance and to prevent wear during bearing replacement after work forming.

Moreover, the 2nd outer rotor 21 'has the surface which fits and fixes the inner ring of the bearing 19', and the ring-shaped member 23 '. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly affected by the difference in the precision and linear expansion coefficient of the member to be assembled. Therefore, in the present embodiment, the inner ring of the bearing 19 'is easy to achieve the machining accuracy, and the linear expansion coefficient is fitted to the yoke 21b, which is approximately the same as the track wheel material of the bearing, without gaps or intermediate fittings. The outer ring of the bearing 19 'is loosely fitted to an austenitic stainless steel bearing holder or an aluminum boss to reduce the rotational accuracy of the bearing 19' and to increase the friction torque due to the temperature rise. It is made of a blocking structure.

In the radially inner side of the partition 13, the second stator 29 ′ is disposed to face the inner circumferential surface of the second outer rotor 21 ′. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 30 'is disposed in the radially inner side of the second stator 29'. The second inner rotor 30 ′ is rotatably supported by the ball bearing 33 ′ against the resolver holder 32 ′ bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the second inner rotor 30 ', a permanent magnet 30a' is mounted via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Therefore, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the first inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet 30a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

The resolver rotors 34a 'and 34b are assembled on the inner circumference of the second inner rotor 30' as a detector for measuring the rotation angle, and in the form opposite to the resolver holder 32 ', the resolver stator ( 35 'and 36' are attached, but in this embodiment, the high resolution incremental resolver stator 35 'and the absolute resolver stator 36' capable of detecting which position of the rotor are located in one rotation are provided. It is located on the second floor. Therefore, even when the power is turned on, the rotation angle of the absolute resolver rotor 34b 'can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The relative rotation angle can be detected without using the pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of magnetic carbon steel as a material so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 30 'rotates at the same speed, ie co-rotation, with respect to the 2nd outer rotor 21' by a magnetic coupling action, the 2nd outer rotor 21 is carried out. The rotation angle of ') can be detected over the partition wall 13. In the present embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the eccentric adjustment and the position of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since the precision can be adjusted, there is no need to provide a hole or cutout for adjustment separately in the housing or both flanges.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and is provided on the outer circumferential surface of the incremental resolver stator 35'. The gears out of phase with respect to the incremental resolver rotor 34a 'at each magnetic pole are provided in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the second inner rotor 30', the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 'changes and the incremental resolver rotor At one rotation of 34a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 24, and used as a position signal. The rotation angle (or rotational speed) of the mental resolver rotor 34a ', that is, the second inner rotor 30' is detected. The resolver rotors 34a 'and 34b' and the resolver stators 35 'and 36' constitute a detector.

In the present embodiment, since the bottom portion 13a of the partition wall 13 is not restrained in the axial direction with respect to the main body 12, due to the dimensional accuracy, the mechanical accuracy, and the temperature change, the partition wall 13 has a dimensional error. Even when deformation occurs, since the bottom portion 13a is not pressed or pulled out by the main body 12, the axial stress and the bending stress of the partition wall 13 can be alleviated, whereby seal failure and breakdown, etc. can be eliminated. You can stop it. Moreover, since the depth of the bottom part 13a and the length dimension of the main body 12 do not need to be processed with high precision, a lower cost direct drive motor can be provided.

In addition, by making the cylindrical portion 13b thin, it is easy to secure the magnetic flux density amount between the rotor and the stator.

In addition, according to the present embodiment, since the magnetic shield plates 25 and 41 are disposed between the first outer rotor 21 and the second outer rotor 21 ', mutual magnetic interference is suppressed, and The inconvenience of driving and accompanying rotation is avoided. Moreover, the outer periphery 12b of the flange part 12a which extends between the direct drive motors D1 and D2 in the main body 12 is made of carbon steel which is a magnetic material, and the first stator 29 and the second Interfering with the stator 29 ', the magnetic field of each other so that they are affected by the missing magnetic flux so that thrust in the wrong rotational direction does not occur in the first outer rotor 21 or the second outer rotor 21'. Functions as a magnetic shield to block

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned inside the radial direction. The main body 12 has a hollow structure, and the flange portion 12a is provided with at least one radial guide hole 12d in communication with the center, and through this, the motor wiring is connected to the center of the main body 12. It is structured to draw out. On the other hand, at least one notch 12e, 12e is provided in the both ends of the main body 12, respectively, and it has a structure which draws the resolver wiring to the center of the main body 12 via these. Such a structure makes it possible to arrange the resolver of the direct motor D1, the stator 29, the stator 29 'of the direct motor D2, and the resolver in this order from the housing side, The angle of the stator and resolver can be easily adjusted. Therefore, by separately preparing a facility for rotationally driving the outer rotor as a reference, the main body 12 incorporating the stator and the resolver is set in the facility so that the angle of the resolver relative to the stator can be adjusted with high accuracy. The fall of the angular positioning accuracy by the commutation difference can be prevented, and the compatibility of the drive control circuit with respect to the two-axis coaxial motor of the present invention can be improved.

25 is a block diagram showing the drive circuits of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D1 and D2 from the three-layer amplifier AMP. As a result, the outer rotors 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1, A2, and FIG. When the outer rotors 21 and 21 'rotate, a resolver signal is output from the resolver stators 35, 36, 35', and 36 'that have detected the rotation angle as described above, so that the resolver digital converter RDC is output. The CPU input after the digital conversion determines whether the outer rotors 21 and 21 'have reached the command position, and when the command position reaches the command position, the outer rotor 21 is stopped by stopping the drive signal to the three-layer amplifier AMP. , 21 ') is stopped. Thereby, servo control of the outer rotors 21 and 21 'becomes possible.

In the case of arm drive in a multiple axis in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In the present embodiment, a variable magnetoresistance comprising an absolute resolver stator 36 and 36 'for detecting an absolute position of one rotation of the rotary shaft, and an incremental resolver stator 35 and 35' for detecting a finer rotational position with a higher resolution. Since the type resolver is adopted, the rotational position control of the outer rotors 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 30 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

FIG. 26 is a sectional view similar to FIG. 23 according to the second embodiment. FIG. This embodiment demonstrates another site | part about embodiment of FIGS. 23-25, and attaches | subjects the same code | symbol about the part which has the same function, and abbreviate | omits description. In addition, in the structure of FIG. 26, although the inner rotor, the stator, and the resolver are shown integrally, they are the same as the structure shown in FIG.

In this embodiment, the annular portion 113a is hermetically coupled to the end 110 of the upper disc portion 110 attached to the upper surface of the cylindrical main body 112 via the O-ring OR using a bolt. have. The lower portion of the annular portion 113a is a thin, radially outwardly flanged portion 113c, and is made by TIG welding the upper end of the thin cylindrical portion 113b to the bent outer edge. The thickness of the annular portion 113a attachment portion is thicker than that of the flange portion 113c and the thin cylindrical portion 113b. The lower end of the thin cylindrical part 113b is TIG-welded to the holder 15 similarly to embodiment mentioned above. The partition 113 is comprised by the annular part 113a, the flange part 113c, the thin cylindrical part 113b, and the holder 15. As shown in FIG. In addition, the housing is constituted by the disc part 110, the main body 112, and the disc 10.

In this embodiment, the upper surface of the upper disc part 110 is closed by the cover member 101, and the bearing holder 107 attached to the outer periphery supports the bearing 19 '. Therefore, the cylindrical member 123 of the direct drive motor D1 does not extend to the direct drive motor D2 side. The bearing holder 117 of the direct drive motor D1 is integrated with the disc 10. The upper disc portion 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.

The installation outer circumferential surface of the bearing holder 107 of the upper disc portion 110 is located radially inward in the thin cylindrical portion 113b, and thus, when the bearing holder 107 is removed from the upper disc portion 110, two The outer rotors 21 and 21 'can be detached to the upper side without disassembling the upper disc portion 110. Therefore, it is not necessary to disassemble an airtight structure at the time of maintenance, etc., and operation can be made easy.

In this embodiment, since the thickness of the flange part 113c (connection part) becomes thin with respect to the thickness of the annular part 113a (attachment part) of the partition 113, it is based on dimensional precision, a mechanical precision, and a temperature change, and a partition Even in the case where an axial stretching stress occurs in the 113, the flange portion 113c deforms, whereby the axial stress and the bending stress of the partition wall 113 can be alleviated, thereby preventing a seal failure or breakage. Can be. In addition, since the annular portion 113a and the upper disc portion 110 or the main body 12 to which the annular portion 113a is attached do not have to be processed with high precision, a lower cost direct drive motor can be provided.

FIG. 27 is a sectional view similar to FIG. 23 according to the third embodiment. FIG. This embodiment demonstrates another site | part about embodiment of FIG. 26, The same code | symbol is attached | subjected about the part which has the same function, and description is abbreviate | omitted. In addition, also in the structure of FIG. 27, although the inner rotor, the stator, and the resolver are shown integrally, they are the same as the structure shown in FIG.

In the present embodiment, the annular portion 213a is hermetically coupled to the end portion 110a of the upper disc portion 110 attached to the upper surface of the cylindrical body 112 through the O-ring OR using a bolt. have. The lower portion of the annular portion 213a has a thin plate shape and a flange portion 213c extending radially outward in a wave shape, and is made by TIG welding the upper end of the thin cylindrical portion 213b to the bent outer edge. The thickness of the annular portion 213a attachment portion is thicker than that of the flange portion 213c and the thin cylindrical portion 213b. The lower end of the thin cylindrical part 213b is TIG-welded to the holder 15 similarly to embodiment mentioned above. The partition wall 213 is comprised by the annular part 213a, the flange part 213c, the thin cylindrical part 213b, and the holder 15. As shown in FIG. In addition, the housing is constituted by the disc part 110, the main body 112, and the disc 10.

Also in this embodiment, the thickness of the flange part 213c (connection part) becomes thin with respect to the thickness of the annular part (attachment part, 213a) of the partition 213, Moreover, the annular part 213a and a thin cylindrical part ( Since the flange portion 213c connecting the 213b is corrugated, the flange portion 213c is deformed even when an expansion stress in the axial direction occurs in the partition wall 213 due to dimensional accuracy, mechanical accuracy, and temperature change. By doing so, the axial stress and the bending stress of the partition wall 213 can be alleviated, whereby a seal failure or breakage can be prevented. Further, since the annular portion 213a and the upper disc portion 110 or the main body 12 to which it is attached do not have to be processed with high precision, a lower cost direct drive motor can be provided.

FIG. 28 is a sectional view similar to FIG. 23 according to the fourth embodiment. FIG. This embodiment demonstrates another site | part about embodiment of FIG. 26, and attaches | subjects the same code | symbol about the part which has the same function, and abbreviate | omits description. In addition, also in the structure of FIG. 25, although the inner rotor, the stator, and the resolver are shown integrally, they are the same as the structure shown in FIG.

In the present embodiment, the annular portion 313a is hermetically sealed through the O-ring (OR) using a bolt to an end portion 110a of the upper disc portion 110 attached to the upper surface of the cylindrical body 112. Are combined. The cylindrical portion 313e has a shape in which a small cylindrical portion 313c and a large cylindrical portion 313b having almost the same thickness are connected by a flange portion 313d, and the upper portion of the cylindrical portion 313c has an annular portion 313a. TIG is welded to the inner circumferential surface of the shell). The thickness of the annular portion 313a is thicker than the thickness of the cylindrical portion 313e. The lower end of the large cylindrical portion 313b is TIG welded to the holder 15 similarly to the above-described embodiment. The partition 313 is comprised by the annular part 313a, the cylindrical part 313e, and the holder 15. As shown in FIG. In addition, the housing is constituted by the disc part 110, the main body 112, and the disc 10.

Also in this embodiment, since the thickness of the cylindrical part 313e becomes thin with respect to the thickness of the annular part 313a (attachment part) of the partition 313, a partition is due to dimensional accuracy, mechanical precision, and temperature change. The flange portion 313d deforms even in the case where an axial expansion stress occurs in the 313 so that the axial stress and the bending stress of the partition wall 313 can be alleviated, thereby preventing a seal failure or breakage. have. In addition, since the annular portion 313a and the upper disc portion 110 or the main body 12 to which it is attached do not have to be processed with high precision, a lower cost direct drive motor can be provided.

In the above embodiment, a surface magnet type 32 pole 36 slot out rotor type brushless motor has been described using an example. However, the present invention is not limited to this type of motor and can be applied to a brushless motor. For example, the permanent magnet embedded type may be sufficient, another slot combination may be sufficient, or an inner rotor type may be sufficient.

In addition, as a countermeasure for each axis, the number of poles and the number of slots of the rotors adjacent to each other in the axial direction may be different. For example, in the case of two-axis coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4-axis coaxials, the first and third axes are 32 poles 36 slots and the second axis. And if the 4th axis is comprised with 24 poles and 27 slots, mutual interference, such as thrust generation of the rotation direction to the rotor and the magnetic coupling device by the magnetic field of each axis, can be prevented.

In addition, although the permanent magnet of the rotor was explained using a neodymium (Nd-Fe-B) magnet and a nickel coating as a coating for improving the corrosion resistance, the material is not limited to this material and surface treatment. It is appropriately changed depending on the environment, for example, and it is necessary to use a magnet of samarium cobalt (Sm · Co) which is difficult to be hot potato depending on the temperature conditions at the time of baking out, and is used in ultra-vacuum. Titanium nitride coating with high outgas barrier property should be given.

In addition, although the yoke was demonstrated using the low carbon steel material and the example which carried out the nickel plating, it is not limited to this material and surface treatment, It changes suitably by the environment etc. used, and especially about surface treatment If it is used in a vacuum, it is necessary to perform carnizen plating, clean S plating, titanium nitride coating, etc., with less pinholes.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed on the outer diameter side of the yoke, but it is appropriately changed according to the environment used, and may be suitable for adhesion depending on the environment. Also good.

In addition, although the bearings 19 and 19 'demonstrated the example using the four-point contact ball bearing of vacuum grease lubrication, it is not limited to this form, material, and lubrication method, but it depends on the environment used, load conditions, rotation speed, etc. The cross-roller bearing may be changed as appropriate, and in the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, it may be referred to as a structure supported by a separate bearing, or a multi-point contact bearing such as when rotating at high speed. If not available, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings. It is also possible to use a metal lubrication without gas discharge, such as plating a soft metal.

In addition, although it demonstrated in the form which used a permanent magnet and a back yoke as an inner rotor which functions as a magnetic coupling, the material and shape of a permanent magnet and a back yoke are not limited to this. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the rotor, or may not be the same width. It is also good for rushing poles that do not use permanent magnets.

Moreover, although it demonstrated as an example using a resolver as an angle detector, it changes suitably by manufacturing cost or resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33 and 33 'rotatably supporting the rotation side of an angle detector, it is not limited to this type and a lubrication method, but it is installation space and friction If the multi-point contact bearing is not available, such as high speed rotation or reduction of friction torque, two angular bearings or deep groove ball bearings are arranged on each axis and preloaded. Also good as.

In addition, the materials, shapes, and manufacturing methods of the structural parts and the partitions arranged outside and inside the other partitions are appropriately changed depending on the production cost, the environment used, the load conditions, and the configuration.

As mentioned above, although this invention was demonstrated with reference to embodiment, it cannot be overemphasized that this invention is limited to the said embodiment, Of course, it can change and improve suitably. For example, the direct drive motor of the present embodiment can be used not only in a vacuum atmosphere but also in an atmosphere outside the atmosphere. For example, in the semiconductor manufacturing process, the reactive gas for etching may be introduced into the vacuum chamber after vacuum evacuation. However, in the direct drive motor of the present embodiment, since the inside and the outside are shielded by the partition wall, the motor There is no fear that the coil or insulating material will be etched.

[Fourth embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. Fig. 29 is a perspective view of a frog leg female conveying apparatus using a motor system comprising a direct drive motor according to the present embodiment. In Fig. 29, two direct drive motors D1 and D2 are connected in series. The first arm A1 is connected to the rotor of the lower direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the upper direct drive motor D2, and the second link L2 L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed.

As apparent from Fig. 29, when the rotors of the direct drive motors D1 and D2 each rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is a direct drive. The motors D1 and D2 are to be approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches.

Thus, for example, in a device having a plurality of arms such as a wafer transfer arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type and a frog leg type shown in the drawing, a plurality of You need a rotating motor. In a vacuum environment, it is necessary to make the contact surface area with the outside world as small as possible, and in order to utilize the space effectively, the attachment holes of the motor and the like should be as small as possible. In addition, in order to convey the wafer W horizontally straight with the least vibration, it is necessary to firmly protect and maintain the moment acting on the tip of the arm at the rotor support. Thus, a plurality of direct drive motors D1 and D2 are connected coaxially in the housing portion, and the connecting portion is tightly bonded (tight bonding by welding, O-ring, metal gasket, etc.) with a seal, and the motor rotor is installed. It is also necessary to separate the space from the space outside the housing.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, in the case of arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized when the power is turned on, the arms A1 and A2 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber. A motor system that coaxially connects a direct drive motor capable of meeting these demands will be described.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36 slot, has four times the configuration of a slot combination of 8-pole 9-slot, which is generally known to have a small cogging force but a magnetic attraction force in the radial direction and a large vibration during rotation. Since the magnetic attraction force in the radial direction is canceled out by 2 ⁿ times (n is an integer), the vibration at the time of rotation can be reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts, In addition, since cogging is inherently small, a very smooth rotation can be obtained. On the other hand, as such a motor having many poles, since the period of the electric angle with respect to the period of the machine angle is large, the positioning controllability is good. Therefore, like the present invention, it is very suitable for a direct drive motor such as driving a robot apparatus without using a speed reducer. In addition, since the thickness, the protrusion width, and the yoke thickness of the rotor can be narrowed without lowering the total magnetic flux amount, it is very suitable for a thin, large diameter and narrow direct drive motor as in the present invention.

FIG. 30 is a view of the configuration of FIG. 29 taken along line II-II and viewed in the direction of the arrow. FIG. With reference to FIG. 30, the internal structure of a two-axis motor system is demonstrated in detail. First, the direct drive motor D1 will be described. The hollow cylindrical body 12, which is coaxially connected to the central opening 10 of the disc 10 fixed to the surface plate G and fixed to each other by bolts 11, has a cup-shaped partition 13 at its upper end. I attach it. The center of the main body 12 can be used in order to communicate with wiring to the stator. The main body 12 and the disc 10 form a housing.

The partition wall 13 is made of stainless steel, which is a nonmagnetic material, and has a bottom portion 13a having a thickness to fit the main body 12, and a thin cylinder extending through the direct drive motors D1 and D2 in the axial direction from its outer circumference. It consists of a part 13b. Therefore, the partition 13 is commonly used for the direct drive motors D1 and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. Here, the welded portion of the cylindrical portion 13b is made to have substantially the same thickness, and the structure prevents heat from escaping only in the component on one side and allows the fitting portion to be welded uniformly. The contact surface between the holder 15 and the disc 10 is grooved to fit the seal member. After the seal member OR is inserted into the groove, the holder 15 and the disc 10 are attached to the bolt 16. By tightening, the fastening portion is separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the partition 13 and the holder 15 are hermetically bonded to each other, and the holder 15 and the disc 10 and the disc 10 and the base G are respectively sealed by an O-ring OR. . Therefore, the inner space surrounded by the disc 10 and the partition 13 is hermetically sealed from the outside. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. In place of hermetically using the O-ring OR, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like.

The bearing holder 17 is integrally formed in the outer peripheral upper surface of the original plate 10. The outer ring of the four-point contact ball bearing 19 used in vacuum is fitted to the bearing holder 17 and is fixed by the bolt 20. On the other hand, the inner ring of the bearing 19 is fitted to the two-ply cylindrical cylindrical member 23 fitted with the first outer rotor member 21, and the bolt 22 which fixes the first outer rotor member 21 simultaneously. It is fixed by). That is, the 1st outer rotor member 21 is rotatably supported with respect to the partition 13 by the cylindrical member 23 which supports arm A1 (FIG. 29). In addition, the outer rotor is constituted by the first outer rotor member 21 and the cylindrical member 23.

The disc 10 (including the bearing holder 17) is made of austenitic stainless steel having high corrosion resistance, and the disc 10 serves as a fitting and sealing device with the base plate G which is a chamber. In the lower surface, a groove 10b for fitting the O-ring OR is provided.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the two-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by quenching. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum. Doing.

In addition, the bearing 19 may use a metal lubrication which plated a soft metal such as gold or silver on the inner ring and the outer ring, and has no outgassing even in vacuum, and is a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor member 21 from (A1) tilts can be received, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used, and in a preloaded state. It may be used or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

Moreover, the cylindrical member 23 has the surface which fits and fixes the inner ring of the bearing 19. Moreover, as shown in FIG. The four-point contact ball bearing 19 is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the accuracy and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19, which is a rotating wheel, can easily be machined with accuracy, and the gap between the cylindrical member 23 is inserted into the cylindrical member 23 having a linear expansion coefficient of about the same as that of the bearing wheel material of the bearing. By loosely fitting the outer ring of the bearing 19 which is a fixed wheel to the bearing holder made of austenitic stainless steel or the holder 17 made of aluminum, it is possible to reduce the rotational accuracy of the bearing 19 and increase the temperature. It is a structure which prevents a raise of friction torque by this.

The first outer rotor member 21 is a permanent magnet 21a, a ring-shaped yoke 21b made of a magnetic body to form a magnetic path, and a non-magnetically fastening member for fastening the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of adults. The permanent magnet 21a is composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternating manner, and are divided into poles, and the individual shapes thereof are linear. to be. The arc centers of the inner diameter and the outer diameter are the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge at the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is an energetic neodymium (Nd-FeB) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase the rust prevention and corrosion resistance after work forming and to prevent wear during bearing replacement.

In the radially inner side of the partition 13, the first stator 29 is disposed to face the inner circumferential surface of the first outer rotor member 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, and is formed of a laminated material of an electromagnetic steel sheet, and is provided as an insulating treatment on each protrusion. After the bobbin is inserted, the motor coil is concentrated. The outer diameter of the first stator 29 is approximately equal to or smaller than the inner diameter of the partition 13.

Adjacent to and parallel to the first stator 29, a first inner rotor 30 is disposed. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 which is bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the first inner rotor 30, a permanent magnet 30a is attached via a back yoke 30b. Like the permanent magnet 21a of the first outer rotor member 21, the permanent magnet 30a is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor member 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a and 34b are assembled on the inner circumference of the first inner rotor 30, and the resolver stators 35 and 36 are disposed on the outer circumference of the resolver holder 32 in a form opposite thereto. Although attached, in this embodiment, the high resolution incremental resolver stator 35 and the absolute resolver stator 36 which can detect which position of a rotor exist in one rotation are arrange | positioned on 2nd floor. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The rotation angle detection used for drive current control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36 which are angle detectors. Later, chromate plating is performed for rust prevention.

In the high resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and is parallel to the rotation axis on the outer circumferential surface of the incremental resolver stator 35. For example, a gear that is out of phase with respect to the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes, and the incremental resolver rotor 34a In one rotation of, the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 31, and used as a position signal. The rotation angle (or rotation speed) of the rotor 34a, that is, the first inner rotor 30 is detected. The detector is constituted by the resolver rotors 34a and 34b and the resolver stators 35 and 36.

According to this embodiment, since the 1st inner rotor 30 by a magnetic coupling action rotates with the same speed, ie co-rotation, with respect to the 1st outer rotor member 21, the 1st outer rotor member 21 is carried out. Can be detected over the partition (13). In addition, in this embodiment, the bearing 33 is formed by the resolver unit without using the parts or housing which form a motor. Therefore, before it is incorporated into a housing, the eccentric adjustment and the resolver coil of the resolver unit are carried out. Since precision adjustment, such as position adjustment, can be performed, it is not necessary to provide a hole or cutout for adjustment in a housing or both flanges separately.

Next, although direct drive motor D2 is demonstrated, the main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and has the inner peripheral surface of the four-point contact ball bearing 19 'used in vacuum. The outer ring is fitted with a fitting and is fixed by the bolt 20 '. On the other hand, the inner ring of the bearing 19 'is fitted to the circumferential surface of the double cylindrical ring-shaped member 23' and is fixed by a bolt 22 'which simultaneously fixes the second outer rotor member 21'. have. That is, the 2nd outer rotor member 21 'is rotatably supported with respect to the partition 13 by the ring-shaped member 23' which supports arm A2 (FIG. 29). Moreover, an outer rotor is comprised by the 2nd outer rotor member 21 'and the ring-shaped member 23'.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the two-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

In addition, the bearing 19 'may be a metal lubrication with no outgassing in the vacuum by plating a soft metal such as gold or silver on the inner and outer rings, and is a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor member 21 'from the arm A1 is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross tapered bearing can be used, and a preload It may be used in a state, or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

Moreover, the ring-shaped member 23 'has the surface which fits and fixes the inner ring of the bearing 19'. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly affected by the difference in the precision and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19 'is easy to achieve the machining accuracy, and the linear expansion coefficient is fitted to the yoke 21b, which is approximately the same as the track wheel material of the bearing, without gaps or intermediate fittings. The outer ring of the bearing 19 'is loosely fitted to an austenitic stainless steel bearing holder or an aluminum boss to prevent the bearing 19' from decreasing the rotational accuracy and increasing the friction torque due to the temperature rise. It is composed.

The second outer rotor member 21 'mechanically forms a ring-shaped yoke 21b' made of a magnetic body to form a permanent magnet 21a 'and a magnetic path, and the permanent magnet 21a' and the yoke 21b 'mechanically. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles. The permanent magnet 21a' is divided into poles, and the individual shapes thereof are linear. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is toward the permanent magnet 21a ', and the permanent magnet 21a' is yoked by screwing the wedge at the outer diameter side of the yoke 21b '. It is fastened to 21b '. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel in order to increase corrosion resistance. The yoke 21b 'is made of a low-carbon steel having high magnetic properties, and nickel plating is applied to prevent rust and corrosion resistance and to prevent wear during bearing replacement after work forming.

In the radially inner side of the partition 13, the second stator 29 ′ is disposed so as to face the inner circumferential surface of the second outer rotor member 21 ′. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

Adjacent to and parallel to the second stator 29 ', a second inner rotor 30' is disposed. The second inner rotor 30 ′ is rotatably supported by the ball bearing 33 ′ against the resolver holder 32 ′ bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the second inner rotor 30 ', a permanent magnet 30a' is mounted via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor member 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Therefore, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor member 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the first inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet 30a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a 'and 34b' are assembled on the inner circumference of the second inner rotor 30 ', and the resolver stator 35 is disposed on the outer circumference of the resolver holder 32' in a form opposite thereto. In the present embodiment, the high resolution incremental resolver stator 35 'and the absolute resolver stator 36' capable of detecting where the rotor is located at one rotation are 2 in this embodiment. Placed on the floor. Therefore, even when the power is turned on, the rotation angle of the absolute resolver rotor 34b 'can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. Detection of the relative rotation angle is enabled without using the pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of magnetic carbon steel as a material so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 30 'rotates at the same speed, ie, co-rotates, with respect to the 2nd outer rotor member 21' by a magnetic coupling action, a 2nd outer rotor member The rotation angle of 21 'can be detected over the partition 13. Moreover, in this embodiment, the resolver unit | piece has a bearing 33 'instead of using the component and housing which form a motor, and therefore, before it is squeezed into a housing, the eccentric adjustment in a resolver unit, the position adjustment of a resolver coil, etc. Since precision can be adjusted, it is not necessary to separately provide adjustment holes or cutouts in the housing or both flanges.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and is provided on the outer circumferential surface of the incremental resolver stator 35'. The gears out of phase with respect to the incremental resolver rotor 34a 'at each magnetic pole are provided in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the second inner rotor 30', the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 'changes and the incremental resolver rotor At one rotation of 34a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 31, and used as a position signal. The rotation angle (or rotational speed) of the mental resolver rotor 34a ', that is, the second inner rotor 30' is detected. The detector is composed of resolver rotors 34a 'and 34b and resolver stators 35' and 36 '.

According to this embodiment, the outer rotor (1st outer rotor (1st outer rotor) of the direct drive motor D1 differs from the outer rotor (2nd outer rotor 21 'and ring-shaped member 23') of the direct drive motor D2. 21) and the cylindrical member 23) are supported by the bearing 19 ', so that when the outer rotor of the direct drive motor D2 is removed, the bearing 19' supporting the outer rotor can be exposed. Next, when the outer rotor of the direct drive motor D1 is removed, the bearing 19 supporting the outer rotor can be exposed, and such inspection and removal can be easily performed. Also improves. In addition, since only the outer rotor outside the partition 13 needs to be removed, there is no need to remove the partition structure, so that a leak check or the like is unnecessary at the time of reassembly, thereby improving assembly performance.

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned in the radial direction inner side. The main body 12 has a hollow structure, and the flange portion 12a is provided with at least one radial guide hole 12d in communication with the center, and the motor wiring of the main body 12 is interposed therebetween. It is structured to be drawn out to the center. On the other hand, at least one notch 12e, 12e is provided in the both ends of the main body 12, and it has a structure which draws the resolver wiring to the center of the main body 12 via these. With such a structure, it becomes possible to arrange | position in the order of the resolver of the direct motor D1, the stator 29, the stator 29 'of the direct motor D2, and the resolver in order from a housing side, The angle between the stator and resolver can be easily adjusted while being biaxial. Therefore, by separately preparing a facility for rotationally driving the outer rotor as a reference, the main body 12 incorporating the stator and the resolver is set in the facility so that the angle of the resolver with respect to the stator can be adjusted with high accuracy. The fall of the angular positioning accuracy by the difference of a tation can be prevented, and the compatibility of the drive control circuit with respect to the 2-axis coaxial motor of this invention can be improved.

32 is a block diagram showing a drive circuit of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D1 and D2 from the three-layer amplifier AMP. As a result, the outer rotor members 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1, A2 and FIG. 29. When the outer rotor members 21, 21 'rotate, the resolver signals are output from the resolver stators 35, 36, 35', 36 'that have detected the rotation angle as described above, so that the resolver digital converter RDC After digital conversion, the input CPU determines whether the outer rotor members 21 and 21 'have reached the command position, and when the command position reaches the command position, stops the drive signal to the three-layer amplifier AMP. The rotation of the members 21 and 21 'is stopped. Thereby, servo control of the outer rotor members 21 and 21 'becomes possible.

In the case of driving a plurality of arms in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In the present embodiment, a variable magnetoresistance comprising an absolute resolver stator 36 and 36 'for detecting an absolute position of one rotation of the rotary shaft, and an incremental resolver stator 35 and 35' for detecting a finer rotational position with a higher resolution. Since the type resolver is adopted, the rotation position control of the outer rotor members 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 30 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is smooth and high precision. An optical encoder adopted as a position detecting means for driving, a magnetic encoder using a magnetoresistive element, or the like can also be used.

33 is a cross-sectional view similar to FIG. 30 according to the second embodiment. This embodiment demonstrates another part about embodiment of FIGS. 30-32, and abbreviate | omits description by attaching | subjecting the same code | symbol about the part which has the same function.

In the present embodiment, the bolt is hermetically bolted to the end portion 110a of the upper disc portion 110 attached to the surface of the cylindrical main body 112 via an annular portion 113a via an O-ring OR. Doing. The lower part of the annular part 113a becomes a thin, radially outward flange part 113c, and is made by TIG welding the upper end of the thin cylindrical part 113b to the bent outer edge. The thickness of the annular portion 113a attachment portion is thicker than that of the flange portion 113c and the thin cylindrical portion 113b. The lower end of the thin cylindrical part 113b is TIG-welded to the holder 15 similarly to embodiment mentioned above. The partition 113 is comprised by the annular part 113a, the flange part 113c, the thin cylindrical part 113b, and the holder 15. As shown in FIG. In addition, the housing is constituted by the disc part 110, the main body 112, and the disc 10.

In this embodiment, the upper surface of the upper disc part 110 is closed by the cover member 101, and the bearing holder 107 attached to the outer periphery supports the bearing 19 '. Therefore, the cylindrical member 123 of the direct drive motor D1 does not extend to the direct drive motor D2 side. The upper disc portion 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.

The outer diameter part 110a of the seating surface of the attachment holder of the bearing holder 107 in the upper disc part 110 is located radially inward rather than the thin cylindrical part 113b, Therefore, the bearing holder 107 is attached to the upper disc part ( When detached from 110, the two outer rotor members 21 and 21 'can be detached upward without disassembling the upper disc part 110. As shown in FIG. Therefore, it is not necessary to disassemble an airtight structure at the time of maintenance, etc., and operation can be made easy. That is, the maximum outer diameter of the housing (main body 12 and the upper disc part 110) that supports the partition structure is the outer rotor (outer rotor members 21 and 21 ') and the ring shape of the direct drive motors D1 and D2. Since the bearing holder 107 is removed from the housing because it is smaller than the inner diameter of the members 23 and 23 ', the outer rotors of the direct drive motors D1 and D2 can be detached from the partition wall 13, thereby. Since inspection and removal can be performed easily, maintenance property is also improved. Furthermore, since only the bearing holder 107 needs to be removed, it is not necessary to remove the partition structure, and a leak check or the like is unnecessary at the time of reassembly, thereby improving the assemblability.

In addition, in this embodiment, since the thickness of the flange part 113c becomes thinner with respect to the thickness of the partition part 113 annular part 113a, the partition part 113 is due to dimensional accuracy, mechanical precision, and temperature change. Even when an axial stretching stress occurs, the thin flange portion 113c deforms, whereby the axial stress and the bending stress of the partition wall 113 can be alleviated, thereby preventing a seal failure or breakage. . In addition, since the annular portion 113a and the upper disc portion 110 or the main body 12 to which the annular portion 113a is attached do not have to be processed with high precision, a lower cost direct drive motor can be provided.

In the above embodiment, a surface magnet type 32 pole 36 slot out rotor type brushless motor has been described using an example. However, the present invention is not limited to this type of motor and can be applied to a brushless motor. For example, the permanent magnet embedded type may be sufficient, another slot combination may be sufficient, or an inner rotor type may be sufficient.

In addition, as a countermeasure for each axis, the number of poles and the number of slots of the rotors adjacent to each other in the axial direction may be different. For example, in the case of biaxial coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4 axes coaxials, the first and third axes are 32 poles 36 slots and the second axis. And if the 4th axis is set as a 24-pole 27 slot, mutual interference of the thrust generation of the rotation direction to the rotor and the magnetic coupling apparatus by the magnetic field of each axis can be prevented.

In addition, the permanent magnet of the rotor was described using a neodymium (Nd-Fe-B) magnet and an example in which nickel coating was used as a coating for improving corrosion resistance, but the material is not limited to this material and surface treatment. It is appropriately changed according to the environment and the like. For example, a samarium cobalt (Sm · Co) magnet that is difficult to be hot potato depending on the temperature conditions at the time of baking out should be used. Titanium nitride coating with high gas barrier properties should be applied.

In addition, although the yoke was demonstrated using the low carbon steel material and the example which performed nickel plating, it is not limited to this material and surface treatment, It changes suitably by the environment used, etc. Especially regarding surface treatment If it is used in ultra-vacuum, it is necessary to carry out a small number of pinholes, plating, cleansing, titanium nitride coating, and the like.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed from the outer diameter side of the yoke, but it is appropriately changed depending on the environment used, and may be bonded depending on the environment. It may be.

In addition, although the bearings 19 and 19 'demonstrated the example using the four-point contact ball bearing of vacuum grease lubrication, it is not limited to this form, material, and lubrication method, but it depends on the environment used, load conditions, rotation speed, etc. It may be changed appropriately, or may be a cross roller bearing, or in the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, it may be a structure supported by a separate bearing, or a multi-point contact bearing such as when rotating at high speed. If not available, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings. It is also possible to use a metal lubrication without gas discharge, such as plating a soft metal.

In addition, although it demonstrated in the form which used a permanent magnet and a back yoke as an inner rotor which functions as a magnetic coupling, the material and shape of a permanent magnet and a back yoke are not limited to this. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the rotor, or may not be the same width. It is also good for bumps that do not use permanent magnets.

Moreover, although the example which used the resolver as an angle detector was demonstrated, it changes suitably by manufacturing cost or resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33 and 33 'which rotatably support the rotation side of an angle detector, It is not limited to this type and a lubrication method, but it is installation space and friction If the multi-point contact bearing is not available, such as high speed rotation or reduction of friction torque, two angular bearings or deep groove ball bearings are arranged on each axis and preloaded. You may make it.

In addition, the materials, shapes, and manufacturing methods of the structural parts and the partitions arranged outside and inside the other partitions are appropriately changed depending on the production cost, the environment used, the load conditions, and the configuration.

As mentioned above, although this invention was demonstrated with reference to embodiment, it cannot be overemphasized that this invention is limited to the said embodiment, Of course, it can change and improve suitably. For example, the motor system of this embodiment is not limited to a vacuum atmosphere, but can be used in an atmosphere outside the atmosphere. For example, in the case of a semiconductor manufacturing process, the reactive gas for etching may be introduce | transduced into a vacuum chamber after vacuum evacuation, but since the inside and the exterior are shielded by the partition in the motor system of this embodiment, a motor coil There is no fear of etching or an insulating material.

[Fifth Embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. 34 is a perspective view of a frog leg female conveying apparatus using the direct drive motor according to the present embodiment. In Fig. 34, four direct drive motors D1, D2, D3, and D4 are connected in series. The first arm A1 is connected to the rotor of the lowermost direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the direct drive motor D2 thereon, and the second link L2 is pivotally connected to the tip of the second arm A2. Further, a first arm A1 'is connected to the rotor of the upper direct drive motor D3, and a first link L1' is pivotably connected to the tip of the first arm A1 '. Further, a second arm A2 'is connected to the rotor of the uppermost direct drive motor D4, and a second link L2' is pivotably connected to the tip of the second arm A2 '. The links L1 and L2 are pivotally connected to the table T on which the wafer W is placed, respectively, and the links L1 'and L2' are on a table T 'on which a separate wafer W is placed. Are pivotally connected to each other.

As apparent from Fig. 34, when the rotors of the direct drive motors D1 and D2 each rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is a direct drive. The motors D1 and D2 are approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches. On the other hand, when the rotors of the direct drive motors D3 and D4 rotate in the same direction, the table T 'also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T' is the direct drive motor ( D3, D4) are to be approached or spaced apart. Therefore, if the direct drive motors D3 and D4 are rotated at any angle, the wafer W can be conveyed to any two-dimensional position within the range where the table T 'touches.

In this way, for example, in a device having a plurality of arms, such as a wafer transfer arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a frog leg type shown in the drawing, a plurality of types are particularly preferable. Of rotation motor is required. In a vacuum environment, the contact surface area with the outside world is made extremely small, and in order to utilize the space effectively, it is necessary to make as few attachment holes as possible for the motor. In addition In order to convey the wafer W horizontally and with very little vibration, it is necessary to firmly protect and hold the moment acting on the tip of the arm at the rotor support. Thus, a plurality of direct drive motors D1, D2, D3, and D4 are coaxially connected in the housing part, and the connection part is tightly joined by a seal (dense joining by welding, O-ring, metal gasket, etc.) It is also necessary to separate the space between the installed space of the rotor and the space outside the housing.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment acting on the tip of arm A1, A2, A1 ', A2' by the rotor support part. In addition, when the arm is driven in a vacuum environment, the arm A1, A2, A1 ', A2', etc. are hit by the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arm is not recognized when the power is turned on. There is a possibility of discarding. A motor system that coaxially connects a direct drive motor capable of meeting these demands will be described.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36 slot, has four times the configuration of a slot combination of 8-pole 9-slot, which is generally known to have a small cogging force but generate magnetic attraction force in the radial direction and a large vibration during rotation. Since the magnetic attraction force in the radial direction is canceled out by 2 ⁿ times (n is an integer), the vibration at the time of rotation can be reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts, In addition, since cogging is inherently small, a very smooth rotation can be obtained. On the other hand, as such a motor having many poles, since the period of the electric angle with respect to the period of the machine angle is large, the positioning controllability is good. Therefore, like the present invention, it is very suitable for a direct drive motor such as driving a robot apparatus without using a speed reducer. In addition, since the thickness, the protrusion width, and the yoke thickness of the rotor can be narrowed without lowering the total magnetic flux amount, it is very suitable for a thin, large diameter and narrow direct drive motor as in the present invention.

FIG. 35 is a view of the configuration of FIG. 34 taken along line II-II and viewed in the direction of the arrow. FIG. With reference to FIG. 35, the internal structure of a four-axis motor system is demonstrated in detail. First, the direct drive motor D1 will be described. The first cylindrical body 12 of the hollow cylinder is fixed to each other by being fitted to the center opening 10a of the disc 10 fixed to the surface plate G by the bolt 11. The 1st main body 12 forms the shaft diameter part 12h in the outer periphery of the upper end. The 2nd main body 112 of the shape similar to the 1st main body 12 forms the large diameter part 112h in the lower end inner periphery. The 1st main body 12 and the 2nd main body 112 are coaxially connected by fitting the shaft diameter part 12h to the large diameter part 112h. The center of the main bodies 12 and 112 can be used in order to carry out wiring to a stator. The housing is constituted by the first main body 12, the disc 10, and the second main body 112.

On the upper surface of the second main body 112, a disc member 110 whose center opening is closed by the lid member 101 is attached. The disk member 110 bolts the upper end of the partition 13 to the lower surface, and attaches the bearing holder 107 to the outer circumference. The disc member 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance. The bearing holder 107 will be described later.

The partition wall 13 is made of stainless steel, which is a nonmagnetic material, and penetrates the disc portion 13a having a thickness attached to the disc member 110 and the direct drive motors D4, D3, D2, and D1 in the axial direction from the outer periphery thereof. It consists of a thin cylindrical portion 13b extending so as to extend. A flange 13c extending from the lower surface of the disk portion 13a is TIG welded to the upper end of the cylindrical portion 13b. That is, the partition 13 is commonly used for the direct drive motors D1 to D4.

The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. Here, the welded portion of the cylindrical portion 13b is made to have substantially the same thickness, and the structure prevents heat from escaping only in the component on one side and allows the fitting portion to be welded uniformly. The contact surface between the holder 15 and the disc 10 is grooved to fit the seal member. After the seal member OR is inserted into the groove, the holder 15 and the disc 10 are attached to the bolt 16. By tightening, the fastening portion is separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the disc member 110 and the partition wall 13, and the partition wall 13 and the holder 15 are hermetically bonded, and the holder 15 and the disc 10, the disc 10 and the surface plate G ) Are each sealed by an O-ring. Therefore, the inner space surrounded by the disc 10, the disc member 110, and the partition wall 13 is hermetically sealed from the outside. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. In place of hermetically using the O-ring OR, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like.

The bearing holder 17 is integrally formed in the outer peripheral upper surface of the original plate 10. The outer ring of the four-point contact ball bearing 19 used in a vacuum is fitted to the bearing holder 17, and is fixed by the bolt 20. As shown in FIG. On the other hand, the inner ring of the bearing 19 is fitted to a two-ply cylindrical cylindrical member 23 containing and fitting the first outer rotor member 21, and bolts for simultaneously fixing the first outer rotor member 21. It is fixed by 22. That is, the 1st outer rotor member 21 is rotatably supported with respect to the partition 13 by the cylindrical member 23 which supports arm A1 (FIG. 34).

In addition, the outer rotor is constituted by the first outer rotor member 21 and the cylindrical member 23.

The disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance, and the disc 10 also serves as a fitting and sealing device with the base plate G, which is a chamber, and the bottom surface thereof. The groove 10b which fits the O-ring OR is provided in this.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the four-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by quenching. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum. Doing.

In addition, the bearing 19 may use the metal lubrication which plated the soft metals, such as gold and silver, on the inner ring and outer ring, and does not have outgas discharge | emission in the vacuum, and since it is a four-point contact ball bearing, Although the first outer rotor member 21 from the arm A1 can receive a moment in the direction to tilt, not only the four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used, and a preload state Or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The first outer rotor member 21 is a ring-shaped yoke 21b made of a magnetic material to form a permanent magnet 21a and a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of these. The permanent magnet 21a is composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternating manner, and are divided into poles, and the individual shapes thereof are linear. to be. The arc centers of the inner diameter and the outer diameter are the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge at the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is an energetic neodymium (Nd-FeB) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetism, and is nickel-plated in order to increase corrosion resistance and corrosion resistance after work forming and to prevent wear during bearing replacement.

In the radially inner side of the partition 13, the first stator 29 is disposed to face the inner circumferential surface of the first outer rotor member 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, and is formed of a laminated material of an electromagnetic steel sheet, and is provided as an insulating treatment on each protrusion. After the bobbin is inserted, the motor coil is concentrated. The outer diameter of the first stator 29 is approximately equal to or smaller than the inner diameter of the partition 13.

Adjacent to and parallel to the first stator 29, a first inner rotor 30 is disposed. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 which is bolted to the outer circumferential surface of the main body 12. The permanent magnet 30a is mounted on the outer circumferential surface of the first inner rotor 30 via the back yoke 30b. The permanent magnet 30a has a 32-pole configuration similar to the permanent magnet 21a of the first outer rotor member 21, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor member 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a and 34b are assembled on the inner circumference of the first inner rotor 30, and the resolver stators 35 and 36 are disposed on the outer circumference of the resolver holder 32 in a form opposite thereto. Although attached, in this embodiment, the high resolution incremental resolver stator 35 and the absolute resolver stator 36 which can detect which position of a rotor exist in one rotation are arrange | positioned on 2nd floor. For this reason, even when the power is turned on, the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known, thereby driving the direct drive motor D1. The rotation angle detection used for current control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36 which are angle detectors. Later, chromate plating is performed for rust prevention.

For the high resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and the rotation axis and the outer peripheral surface of the incremental resolver stator 35 In parallel, a gear having a phase out of the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes, and the incremental resolver rotor 34a The fundamental wave component of the magnetoresistance change is n period in one rotation of, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 36, and used as a position signal. 34a), that is, the rotation angle (or rotation speed) of the first inner rotor 30 is detected. The detector is constituted by the resolver rotors 34a and 34b and the resolver stators 35 and 36.

According to this embodiment, the 1st outer rotor member 21 rotates with respect to the 1st outer rotor member 21 at the same speed, ie, co-rotation, by a magnetic coupling action. Can be detected over the partition (13). Moreover, in this embodiment, the bearing unit 33 is provided by the resolver unit without using the component or housing which forms a motor, and therefore, before it is squeezed into a housing, such as eccentricity adjustment in the resolver unit, position adjustment of a resolver coil, etc. Since precision can be adjusted, it is not necessary to separately provide adjustment holes and cutouts in the housing or both flanges.

Next, although the direct drive motor D2 is demonstrated, the 1st main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and the four-point contact ball bearing 19 'used in vacuum on the inner peripheral surface thereof. The outer ring is fitted in a fitting manner and is fixed by bolts 20 '. On the other hand, the inner ring of the bearing 19 'is fitted to the circumferential surface of the double cylindrical ring-shaped member 23' and is fixed by a bolt 22 'which simultaneously fixes the second outer rotor member 21'. have. That is, the 2nd outer rotor member 21 'is rotatably supported with respect to the partition 13 by the ring-shaped member 23' which supports arm A2 (FIG. 34). Moreover, an outer rotor is comprised by the 2nd outer rotor member 21 'and the ring-shaped member 23'.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the four-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

In addition, the bearing 19 'may be a metal lubrication with no outgassing in the vacuum by plating a soft metal such as gold or silver on the inner and outer rings, and is a four-point contact ball bearing. Although the moment in the direction in which the second outer rotor member 21 'from the arm A1 is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross tapered bearing can be used, and a preload It may be used in a state, or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

Moreover, the ring-shaped member 23 'has the surface which fits and fixes the inner ring of the bearing 19'. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly affected by the difference in the precision and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19 ', which is a rotating wheel, can be easily fitted with a ring-shaped member 23' having a linear expansion coefficient of approximately the same as the track wheel material of the bearing. Or intermediate fitting and loosely fitting the outer ring of the bearing 19 ', which is a fixed wheel, to the inner circumference of the cylindrical member 23, thereby reducing the frictional accuracy due to a decrease in the rotational accuracy of the bearing 19' or an increase in temperature. It is a structure which prevents a rise.

The second outer rotor member 21 'mechanically forms a ring-shaped yoke 21b' made of a magnetic body to form a permanent magnet 21a 'and a magnetic path, and the permanent magnet 21a' and the yoke 21b 'mechanically. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles. The permanent magnet 21a' is divided into poles, and the individual shapes thereof are linear. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a ', and the permanent magnet 21a' is screwed by screwing the wedge at the outer diameter side of the yoke 21b '. 21b '). With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b 'is made of a low-carbon steel having high magnetic properties, and nickel plating is applied to prevent rust and corrosion resistance and to prevent wear during bearing replacement after work forming.

In the radially inner side of the partition 13, the second stator 29 ′ is disposed so as to face the inner circumferential surface of the second outer rotor member 21 ′. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the first main body 12, formed of a laminated material of an electromagnetic steel sheet, and each protrusion After the bobbin is sandwiched as an insulation treatment, the motor coil is concentrated. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 30 'is disposed in the radially inner side of the second stator 29'. The second inner rotor 30 'is rotatably supported by the ball bearing 33' with respect to the resolver holder 32 'which is bolted to the outer circumferential surface of the first main body 12. As shown in FIG. A permanent magnet 30a 'is attached to the outer circumferential surface of the second inner rotor 30' via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor member 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Therefore, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor member 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the second inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet 30a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

A resolver rotor 34b 'is assembled on the inner circumference of the second inner rotor 30' as a detector for measuring the rotation angle, and in a form opposite to the resolver holder 32 ', on the outer circumference of the resolver holder 32'. 36 '), the present invention has two layers of high resolution incremental resolver stator 35' and an absolute resolver stator 36 'capable of detecting where the rotor is located at one rotation. Posted in Therefore, even when the power is turned on, the rotation angle of the absolute resolver rotor 34 'can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. Detection of the relative rotation angle is enabled without using the pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of magnetic carbon steel as a material so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 30 'rotates at the same speed, ie, co-rotates, with respect to the 2nd outer rotor member 21' by a magnetic coupling action, a 2nd outer rotor member The rotation angle of 21 'can be detected over the partition 13. In the present embodiment, the bearing 33 'is formed by the resolver unit alone without using a component or a housing forming the motor. Therefore, the eccentric adjustment and the position of the resolver coil in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes and cutouts in the housing or both flanges.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and is provided on the outer circumferential surface of the incremental resolver stator 35'. The gears out of phase with respect to the incremental resolver rotor 34a 'at each magnetic pole are provided in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35' changes, and the incremental resolver rotor ( 34a ') makes the fundamental wave component of the magnetoresistance change n cycles in one rotation, detects the magnetoresistance change, digitizes it by the resolver control circuit shown in FIG. 36, and uses it as a position signal. The rotation angle (or rotation speed) of the resolver rotor 34a ', that is, the first inner rotor 30 is detected. The detector is composed of resolver rotors 34a 'and 34b' and resolver stators 35 'and 36'.

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned inside the radial direction. 1st The main body 12 has a hollow structure, and the flange portion 12a is provided with at least one radial guide hole 12d in communication with the center, and through this, the motor wiring is connected to the first main body 12. It is structured to withdraw to the center of On the other hand, at both ends of the first main body 12, at least one notch 12e and 12e are provided, respectively, and the structure is such that the wiring of the resolver is led out to the center of the first main body 12 via these. have. With such a structure, it becomes possible to arrange | position in the order of the resolver of the direct motor D1, the stator 29, the stator 29 'of the direct motor D2, and the resolver in order from a housing side, The angle of the stator and resolver can be easily adjusted. Therefore, if a facility for rotationally driving the outer rotor serving as a reference is separately prepared, the first body 12 incorporating the stator and the resolver is set in the facility so that the angle of the resolver relative to the stator can be adjusted with high accuracy. Therefore, the fall of the angle positioning precision by the commutation difference can be prevented, and the compatibility of the drive control circuit with respect to the four-axis coaxial motor of this invention can be improved.

FIG. 37 is a block diagram showing a drive circuit of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D1 and D2 from the three-layer amplifier AMP. As a result, the outer rotor members 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1, A2 and Fig. 34. When the outer rotor members 21, 21 'rotate, the resolver signal is output from the resolver stators 35, 36, 35', 36 'which have detected the rotation angle as described above, so that the resolver digital converter RDC After digital conversion, the input CPU determines whether the outer rotor members 21 and 21 'have reached the command position, and when the command position reaches the command position, stops the drive signal to the three-layer amplifier AMP. The rotation of the members 21 and 21 'is stopped. Thereby, servo control of the outer rotor members 21 and 21 'becomes possible.

In the case of arm drive in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In the present embodiment, a variable magnetoresistance comprising an absolute resolver stator 36 and 36 'for detecting an absolute position of one rotation of the rotary shaft, and an incremental resolver stator 35 and 35' for detecting a finer rotational position with a higher resolution. Since the type resolver is adopted, the rotation position control of the outer rotor members 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 30 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

Next, the direct drive motor D4 will be described. The outer ring of the four-point contact ball bearing 119 used in vacuum is fitted to the bearing holder 107 bolted to be detachable from the disc member 110 attached to the second main body 112. It is attached to and fixed by the bolt (120). On the other hand, the inner ring of the bearing 119 is fitted to a two-ply cylindrical cylindrical member 123 containing and fitting the first outer rotor member 121, and bolts for simultaneously fixing the first outer rotor member 121. It is fixed by 122. That is, the 1st outer rotor member 121 is rotatably supported with respect to the partition 113 by the cylindrical member 123 which supports arm A2 '(FIG. 34). In addition, the outer rotor is constituted by the first outer rotor member 121 and the cylindrical member 123.

The bearing holder 107 is made of austenitic stainless steel having high corrosion resistance. The bearing 119 is a four-point contact ball bearing capable of loading radial, axial, and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D4 ends with one, the four-axis coaxial motor system of the present invention can be thinned. The bearing 119 is made of a martensitic stainless steel which has high corrosion resistance in both inner and outer rings and can be hardened by quenching. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum. Doing.

The bearing 119 may be formed by plating a soft metal such as gold or silver on the inner ring and the outer ring, and using metal lubrication without outgassing even in vacuum, and is a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor member 121 from the arm A2 'is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used, and a preload It may be used in a state, or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The first outer rotor member 121 is a ring-shaped yoke 121b made of a magnetic body to form a permanent magnet 121a and a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 121a and the yoke 121b. It is comprised by the wedge (not shown) which consists of these. The permanent magnet 121a is composed of 32 poles, and magnets of N pole and S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles, and is divided into poles, and the individual shapes thereof are linear. to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is toward the permanent magnet 121a, and the permanent magnet 121a is screwed on the yoke 121b by screwing the wedge at the outer diameter side of the yoke 121b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 121a is a high energy neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 121b is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase the rust prevention and corrosion resistance after work forming and to prevent wear during bearing replacement.

In the radially inner side of the partition 113, the first stator 129 is disposed to face the inner circumferential surface of the first outer rotor member 121. The first stator 129 is attached to a cylindrically deformed lower portion of the flange portion 112a extending radially from the center of the main body 112, and is formed of a laminated material of an electromagnetic steel sheet, and is provided as an insulating treatment on each protrusion. After the bobbin is inserted, the motor coil is concentrated. The outer diameter of the first stator 129 is approximately the same as or smaller than the inner diameter of the partition wall 13.

The first inner rotor 130 is disposed adjacent to and parallel to the first stator 129. The first inner rotor 130 is rotatably supported by the ball bearing 133 with respect to the resolver holder 132 that is bolted to the outer circumferential surface of the second main body 112. The permanent magnet 130a is mounted on the outer circumferential surface of the first inner rotor 130 via the back yoke 130b. The permanent magnet 130a has a 32-pole configuration like the permanent magnet 121a of the first outer rotor member 121, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 130 is co-rotated in synchronization with the first outer rotor member 121 driven by the first stator 129.

The bearing 133 rotatably supporting the first inner rotor 130 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D4 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 130a is adhesively fixed to the back yoke 130b. The permanent magnet 130a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 130b is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 134a and 134b are assembled on the inner circumference of the first inner rotor 130 and the resolver stators 135 and 136 are disposed on the outer circumference of the resolver holder 132 in a form opposite thereto. Although attached, in this embodiment, the high resolution incremental resolver stator 135 and the absolute resolver stator 136 which can detect which position of a rotor exist in 1 rotation are arrange | positioned in the 2nd floor. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 134b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The rotation angle detection used for drive current control is enabled without using a pole detection sensor.

The resolver holder 132 and the first inner rotor 130 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 135 and 136, which are angle detectors. Later, chromate plating is performed for rust prevention.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 134a has a plurality of slot teeth having a constant pitch, and the rotation axis and the outer peripheral surface of the incremental resolver stator 135 In parallel, a gear having a phase out of the incremental resolver rotor 134a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 134a rotates integrally with the first inner rotor 130, the magnetic resistance between the magnetic resolver of the incremental resolver stator 135 changes, and the incremental resolver rotor 134a is rotated. Incremental resolver rotor 134a by allowing the fundamental wave component of the magnetoresistance change to n cycles by one rotation of the signal, detecting the magnetoresistance change, digitizing by the resolver control circuit illustrated in FIG. 36, and using it as a position signal. That is, the rotation angle (or rotation speed) of the first inner rotor 130 is detected. The detector is constituted by the resolver rotors 134a and 134b and the resolver stators 135 and 136.

According to this embodiment, since the 1st inner rotor 130 rotates at the same speed, ie co-rotation, with respect to the 1st outer rotor member 121 by a magnetic coupling action, the 1st outer rotor member 121 is carried out. ) Can be detected over the partition wall (13). In addition, in this embodiment, the bearing 133 is provided by the resolver unit without using the component or housing which forms a motor. Therefore, before it is woven into a housing, the eccentric adjustment in the resolver unit, the position adjustment of a resolver coil, etc. are carried out. Since precision can be adjusted, it is not necessary to separately provide adjustment holes and cutouts in the housing or both flanges.

Next, although the direct drive motor D3 is demonstrated, the 2nd main body 112 comprises a housing here. The cylindrical member 123 of the above-mentioned direct drive motor D4 extends downward to the position to superpose | polymerize with the direct drive motor D3, and the four-point contact ball bearing 119 'which can be used in vacuum on the inner peripheral surface is provided. The outer ring is fitted with a fitting, and is fixed by the bolt 120 '. On the other hand, the inner ring of the bearing 119 'is fitted to the circumferential surface of the double cylindrical ring-shaped member 123', and is fixed by a bolt 122 'which simultaneously fixes the second outer rotor member 121'. have. That is, the 2nd outer rotor member 121 'is rotatably supported with respect to the partition 13 by the ring-shaped member 123' which supports arm A1 ', FIG.

Moreover, an outer rotor is comprised by the 2nd outer rotor member 121 'and the ring-shaped member 123'.

Bearing 119 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D3 ends with one, the four-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

In addition, the bearing 119 'may use the metal lubrication which plated soft metals, such as gold and silver, on the inner ring and outer ring, and does not discharge | emit outgassing in a vacuum, and since it is a four-point contact ball bearing, Although the moment in the direction in which the second outer rotor member 121 'tilts from the arm A1' can be received, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used. It may be used in a preloaded state, or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The second outer rotor member 121 'mechanically processes the permanent magnet 121a' and the ring-shaped yoke 121b 'made of a magnetic body to form a magnetic path, and the permanent magnets 121a' and the yoke 121b '. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening by the said structure. The permanent magnet 121a 'is composed of 32 poles, and magnets of N and S poles are made of magnetic metal in each of 16 alternations. The permanent magnets 121a' are divided into poles, each of which has a linear shape. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential section is directed toward the permanent magnet 121a ', and the permanent magnet 121a' is screwed by screwing the wedge from the outer diameter side of the yoke 121b '. 121b '). With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 121a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 121b 'is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase corrosion resistance and corrosion resistance after work forming and to prevent wear during bearing replacement.

In the radially inner side of the partition 13, the second stator 129 ′ is disposed to face the inner circumferential surface of the second outer rotor member 121 ′. The second stator 129 'is attached to a cylindrically deformed upper portion of the flange portion 112a extending radially from the center of the second main body 112, and formed of a laminated material of an electromagnetic steel sheet, and each protrusion After the bobbin is sandwiched as an insulation treatment, the motor coil is concentrated. The outer diameter of the second stator 129 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 130 ′ is disposed radially inward of the second stator 129 ′.

The second inner rotor 130 ′ is rotatably supported by the ball bearing 133 ′ against the resolver holder 132 ′ which is bolted to the outer circumferential surface of the second main body 112. A permanent magnet 130a 'is attached to the outer circumferential surface of the second inner rotor 130' via the back yoke 130b '. Like the permanent magnet 121a 'of the second outer rotor member 121', the permanent magnets 130a 'are composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternating manner. Therefore, the second inner rotor 130 'is driven to rotate in synchronization with the second outer rotor member 121' by the second stator 129 '.

The bearing 33 'rotatably supporting the second inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D3 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 130a 'is adhesively fixed to the back yoke 130b'. The permanent magnet 130a 'is a high energy neodymium (Nd-Fe-B) magnet, and is coated with nickel to prevent demagnetization due to rust. The yoke 130b 'is made of low-carbon steel having high magnetic properties, and chromate plating is performed for rust prevention after work forming.

Resolver rotors 134a 'and 134b' are assembled on the inner circumference of the second inner rotor 130 ', and the resolver stator 135 is disposed on the outer circumference of the resolver holder 132' in a form opposite thereto. 136 '), but in the present embodiment, the high resolution incremental resolver stator 135' and the absolute resolver stator 136 'capable of detecting which position of the rotor are located in one rotation are provided. It is located on the second floor. Therefore, even when the power supply is turned on, the rotation angle of the detection rotor 134 'can be known, the zero point return is not necessary, and the electrical phase angle of the magnet with respect to the coil can be known. Detection of the relative rotation angle is enabled without using the pole detection sensor.

The resolver holder 132 ′ and the second inner rotor 130 ′ are made of a magnetic material of carbon steel so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 135 ′ and 136 ′, which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 130 'rotates at the same speed, ie co-rotation, with respect to the 2nd outer rotor member 121' by a magnetic coupling action, a 2nd outer rotor member The rotation angle of 121 'can be detected over the partition 13. In this embodiment, the bearing 133 'is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the eccentric adjustment and the position of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes or cutouts in the housing or both flanges.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 134a 'has a plurality of slot teeth having a constant pitch, and the magnetic pole of the incremental resolver stator 135' The outer circumferential surface is provided with a tooth which is out of phase with respect to the incremental resolver rotor 134a 'at each magnetic pole in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 134a 'rotates integrally with the second inner rotor 130', the magnetic resistance between the magnetic resolver of the incremental resolver stator 135 'changes, and the incremental resolver rotor In one rotation of 134a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 36, and used as a position signal. The rotational angle (or rotational speed) of the elemental resolver rotor 134a ', that is, the second inner rotor 130' is detected. The detector is composed of resolver rotors 134a 'and 134b' and resolver stators 135 'and 136'.

Moreover, the 1st stator 129 and the 2nd stator 129 'are arrange | positioned up and down centering on the flange part 112a, and the resolver is arrange | positioned inside the radial direction. Moreover, the 2nd main body 112 is hollow structure, The flange part 112a is provided with at least 1 radial guide hole 112d which communicates to the center, and the motor wiring is connected 2nd through this. It is structured to be drawn out to the center of the main body 112 of the. On the other hand, at least one notch 112e, 112e is provided in the both ends of the 2nd main body 112, and it has a structure which draws the resolver wiring to the center of the 2nd main body 112 via these. With such a structure, the resolver of the direct motor D4, the stator 129, the stator 129 'of the direct motor D3, and the resolver can be arranged in this order from the housing side. The angle of the stator and resolver can be easily adjusted. Therefore, by separately preparing a facility for rotationally driving the outer rotor as a reference, the second body 112 incorporating the stator and the resolver is set in the facility so that the angle of the resolver relative to the stator can be adjusted with high accuracy. Therefore, the difference in commutation The fall of the angle positioning precision by this can be prevented, and the compatibility of the drive control circuit with respect to the 4-axis coaxial motor of this invention can be improved.

FIG. 37 is a block diagram showing a drive circuit of the direct drive motors D1 and D2. When the motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D3 and the motor control circuit DMC2 for the direct drive motor D4 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D3 and D4 from the three-layer amplifier AMP. As a result, the outer rotor members 121 and 121 'of the direct drive motors D3 and D4 rotate independently to move the arms A1', A2 ', and FIG. When the outer rotor members 121 and 121 'rotate, the resolver signals are output from the resolver stators 135, 136, 135', and 136 'that have detected the rotation angle as described above, and thus, the resolver digital converter RDC. After digital conversion, the input CPU determines whether the outer rotor members 121 and 121 'have reached the command position, and when the command position reaches the command position, stops the drive signal to the three-layer amplifier AMP. The rotation of the members 121 and 121 'is stopped. This enables servo control of the outer rotor members 121 and 121 '.

When the arm is driven in a vacuum environment, the arm A1 'may hit the wall of the vacuum chamber or the shutter of the vacuum chamber unless the current rotation position of the arms A1' and A2 'is recognized when the power is turned on. However, in the present embodiment, the absolute resolver stator 136 and 136 'for detecting the absolute position of one rotation of the rotary shaft and the incremental resolver stator 135 and 135' for detecting the finer rotational position with more resolution are provided. Since the variable magneto-resistive resolver is employed, the rotational position control of the outer rotor members 121, 121 ', that is, the arms A1', A2 'can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 130 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

The cylindrical member 123 constituting the outer rotor of the (first) direct drive motor D4 closest to the upper end of the motor system according to the present embodiment can be detached from the housing (here, the cylindrical member 110). The outer diameter part 110a of the mounting seat surface of the bearing holder 107 in the cylindrical member 110 is supported by the bearing 119 with respect to the bearing holder 107 attached | attached easily. Is located in the radial direction rather than). Therefore, when the bearing holder 107 is removed, the cylindrical member 123 'of the direct drive motor D3 supported by the bearing 119' together with the cylindrical member 123 of the direct drive motor D4 is removed. The outer rotor members 121 and 121 'can be detached from the partition 13 integrally, and then the direct drive motors D2 and D1 can be detached, thereby making it easy to check or remove them. Since it can be performed, maintainability also improves. In addition, since only the bearing holder 107 needs to be removed, the partition structure does not need to be removed, and a leak check or the like is unnecessary at the time of reassembly, thereby improving assembly performance.

In the housing of this embodiment, the 1st main body 12 and the 2nd main body 112 are connectable to an arbitrary phase in the axial direction, ie, the two adjacent direct drive motors D1, D2, and D3 are adjacent. , D4) is fixed by bolts so that it can be removed for every unit commonly used. The first main body 12 has an angle detector of the direct drive motor D1, a stator (stator) of the direct drive motor D1, a stator of the direct drive motor D2, and a direct drive in order from the disc 10 side. In order of the angle detector of the motor D2, and the 2nd main body 112 in order from the 1st main body 12 side, the angle detector of the direct drive motor D3 axis, and the stator of the direct drive motor D3 axis. The stator of the direct drive motor D4 and the angle detector of the direct drive motor D4 can be arranged in this order, and the angle detector can be easily adjusted for each axis with respect to the stator. Therefore, if a separate equipment for rotationally driving the motor rotor as a reference is prepared, the first body or the second body incorporating the motor stator and the rotation detector are set in the equipment, and the angle to the motor stator is individually set. Since the angle adjustment of the detector can be made with high accuracy, it is possible to prevent the deterioration of the angle positioning accuracy due to the commutation difference, and the adjustment after assembly is easy or unnecessary, and the compatibility of the drive control circuit with respect to the four-axis coaxial motor of the present invention. Can increase.

In the above embodiment, the surface magnet type 32 pole 36 slot out rotor brushless motor has been described using an example. However, the present invention is not limited to this type of motor and is applicable to a brushless motor. A magnetic pole type, for example, a permanent magnet embedded type, may be other slot combinations, or may be an inner rotor type.

In addition, as a countermeasure for each axis, the number of poles and the number of slots of the rotors adjacent to each other in the axial direction may be different. For example, in the case of 4-axis coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4-axis coaxials, the first and third axes are 32 poles 36 slots and the second axis. When the fourth axis has a configuration of 24 poles and 27 slots, mutual interference such as thrust generation in the rotational direction of the rotor and the magnetic coupling device due to the magnetic field of each axis can be prevented.

In addition, the permanent magnet of the rotor was described using an example in which nickel coating was used as a coating for enhancing corrosion resistance using a neodymium (Nd-Fe-B) magnet, but the material and the surface treatment are not limited thereto. The sagium cobalt (Sm · Co) magnet, which is difficult to reduce the high temperature depending on the temperature conditions at the time of baking out, should be used. Titanium nitride coating having high properties should be applied.

In addition, although the yoke was demonstrated using the example which made low carbon steel the material and performed nickel plating, it is not limited to this material and surface treatment, It changes suitably by the environment etc. used, Especially about surface treatment If it is used in a vacuum, it is necessary to carry out pinage less carnizen, plating or clean S plating, and titanium nitride coating.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed from the outer diameter side of the yoke, but it is appropriately changed according to the environment used, and may be suitable for adhesion depending on the environment. Also good for.

Although the bearings 19, 19 ', 119, 119' have been described using a four-point contact ball bearing with vacuum grease lubrication, they are not limited to this type, material, and lubrication method. , The cross roller bearing may be appropriately changed depending on the rotational speed or the like. In the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, a structure supported by a separate bearing may be used, or when rotating at a high speed. If a multi-point contact bearing is not available, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings. You may use the thing made into metal lubrication without gas release like plating a soft metal, such as gold and silver.

In addition, although it demonstrated in the form which used a permanent magnet and a back yoke as an inner rotor which functions as a magnetic coupling, the material and shape of a permanent magnet and a back yoke are not limited to this. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the outer rotor or may not be the same width. It is also good for rushing poles that do not use permanent magnets.

Moreover, although the example which used the resolver as an angle detector was demonstrated, it changes suitably by manufacturing cost and resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33, 33 ', 133, 133' rotatably supporting the rotation side of an angle detector, it is not limited to this form and a lubrication method. If the multi-point contact bearing cannot be used, such as high speed rotation or reduction of friction torque, two angular bearings or deep groove ball bearings should be arranged for each axis. The structure may be configured to apply a preload.

In addition, the materials, shapes, and manufacturing methods of the structural parts and the partitions arranged outside and inside the other partitions are appropriately changed depending on the production cost, the environment used, the load conditions, and the configuration.

The above-described motor system uses the magnetic flux leaked from the rotor, the stator, and the magnetic coupling used in the resolver of each axis so that the thrust in the rotational direction is not generated in the magnetic coupling used in the rotor or the rotation detector. Magnetic shields for shielding magnetic fields are installed between the rotors of each axis, or magnetic shields for shielding each other's electromagnetic fields so as not to interfere with each other's resolvers by electromagnetic fields generated from rotors, stators, and resolvers on each axis, or By changing the number of poles of the rotor and the number of slots of the stator between adjacent axes, it is possible to shorten the axial length of each axis and the axial distance of each axis. have. Therefore, the structure which suppressed the whole shaft length while being a multi-axis coaxial motor system called 4-axis coaxial and 4-axis coaxial is possible. In particular, in a system using a direct drive motor with a multi-axis configuration called 4-axis coaxial, two prog leg female robots can be installed, which can accurately position the chamber without greatly changing the chamber structure. Improve performance and uptime. It goes without saying that it can also be used for four or more motor systems.

As mentioned above, although this invention was demonstrated with reference to embodiment, this invention is not limited to the said embodiment, Of course, it can change and improve suitably. For example, the direct drive motor of the present embodiment can be used not only in a vacuum atmosphere but also in an atmosphere outside the atmosphere. For example, in the semiconductor manufacturing process, the reactive gas for etching may be introduced into the vacuum chamber after vacuum evacuation. However, in the direct drive motor of the present embodiment, since the inside and the outside are shielded by the partition wall, the motor There is no fear that the coil or the insulating material may be etched.

[Sixth Embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. 38 is a perspective view of a frog leg female conveying apparatus using the direct drive motor according to the present embodiment. In Fig. 38, two direct drive motors D1 and D2 are connected in series. A first arm A1 is connected to the rotor of the lower (first) direct drive motor D1, and a first link L1 is pivotably connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the upper (second) direct drive motor D2, and the second link L2 is pivotally connected to the distal end of the second arm A2. . The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed.

As apparent from FIG. 38, when the rotors of the direct drive motors D1 and D2 rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is a direct drive. The motors D1 and D2 are approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches.

In this way, for example, in a device having a plurality of arms, such as a wafer transfer arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a frog leg type shown in the drawing, a plurality of types are particularly preferable. Of rotation motor is required. In a vacuum environment, it is necessary to make the contact surface area with the outside world as small as possible, and to make as small an attachment hole as possible for the motor and the like in order to effectively utilize the space. In addition, in order to convey the wafer W horizontally straight with the least vibration, it is necessary to firmly protect and maintain the moment acting on the tip of the arm at the rotor support. Thus, a plurality of direct drive motors D1 and D2 are coaxially connected in the housing part, and the connecting part is tightly joined by a seal (dense joint by welding, O-ring, metal gasket, etc.), and the installed space of the motor rotor. It is also necessary to space the space outside the housing.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, in the case of arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized when the power is turned on, the arms A1 and A2 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber. A motor system that coaxially connects a direct drive motor capable of meeting these demands will be described.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36 slot, has four times the configuration of a slot combination of 8-pole 9-slot, which is generally known to have a small cogging force but generate magnetic attraction force in the radial direction and a large vibration during rotation. Since the magnetic attraction force in the radial direction is canceled out by 2 ⁿ times (n is an integer), the vibration at the time of rotation can be reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts, In addition, since cogging is inherently small, a very smooth rotation can be obtained. On the other hand, as such a motor having many poles, since the period of the electric angle with respect to the period of the machine angle is large, the positioning controllability is good. Therefore, like the present invention, it is very suitable for a direct drive motor such as driving a robot apparatus without using a speed reducer. Moreover, since the thickness, the protrusion width | variety, and the yoke thickness of a rotor can be narrowed without lowering the total magnetic flux amount, it is suitable for a thin, large diameter and narrow direct drive motor like this invention.

FIG. 39 is a view of the configuration of FIG. 38 taken along line II-II and viewed in the direction of the arrow. Referring to Fig. 39, the internal structure of the two-axis motor system will be described in detail. First, the direct drive motor D1 will be described. The hollow cylindrical bodies 12 fixed to each other by bolts 11 fitted to the central opening 10a of the disc 10 fixed to the surface plate G have a cup-shaped partition 13 attached to the upper end thereof. Doing. The center of the main body 12 can be used in order to communicate with wiring to the stator. The main body 12 and the disc 10 comprise a housing.

The partition 13 is made of stainless steel, which is a nonmagnetic material, and has a bottom portion 13a having a thickness to fit the main body 12 and a thin cylindrical portion extending through the direct drive motors D1 and D2 in the axial direction from its outer circumference. 13b and the holder 15. Therefore, the partition 13 is commonly used for the direct drive motors D1 and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. Here, the welded portions of the cylindrical portion 13b and the holder 15 are made to have approximately the same thickness, and the structure is such that the heat escapes only to the components on one side, and the fitting portion can be welded uniformly. The contact surface between the holder 15 and the disc 10 is grooved to fit the seal member. After the seal member OR is inserted into the groove, the holder 15 and the disc 10 are attached to the bolt 16. By tightening, the fastening portion is separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the partition 13 and the holder 15 are hermetically bonded, and the holder 15 and the disc 10, and the disc 10 and the surface plate G are respectively sealed by an O-ring OR. . Therefore, the inner space surrounded by the disc 10 and the partition 13 is hermetically sealed from the outside. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. In place of hermetically using the O-ring OR, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like.

On the outer circumferential upper surface of the original plate 10 serving as the atmospheric outer member, a bearing holder 17 which is separate from it is fixed by a bolt 18. The bolt 18 is disposed outside the cylindrical member 23 and exposes the head portion thereof. The outer ring of the four-point contact ball bearing (first bearing, 19) used in vacuum is fitted and fitted to the bearing holder 17, and is fixed by the bolt 20 via an annular bearing restraint (BH). It is. On the other hand, the inner ring of the bearing 19 is fitted to the outer circumference of the first outer rotor 21 and is fixed by the bolt 22 via the annular bearing restraint BH. That is, the 1st outer rotor 21 is rotatably supported by the bearing 19 with respect to the bearing holder 17 and the partition 13, and also has the cylindrical member which supports the arm A1 (FIG. 38) ( 23 is fixed to the upper surface by bolts 24. Here, the bolt 24 can fix the magnetic shield plate 25 (illustrated by the dotted line) which extends radially inward to the cylindrical member 23 simultaneously. The outer rotor is constituted by the first outer rotor 21 and the cylindrical member 23.

The disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance, and the disc 10 also serves as a fitting and sealing device with the base plate G, which is a chamber. The groove 10b for fitting the O-ring OR is provided.

The magnetic shield plate 25 is nickel-plated in order to improve antirust and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The effect is mentioned later.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the two-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by quenching. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum. Doing.

In addition, the bearing 19 may use a metal lubrication which plated a soft metal such as gold or silver on the inner ring and the outer ring, and has no outgassing even in vacuum, and is a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor 21 from (A1) tilts can be received, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used, and are used in a preload state. In order to improve lubricity, a fluorine-based coating treatment (DFO) may be performed.

The first outer rotor 21 is a permanent magnet 21a, a ring-shaped yoke 21b made of magnetic material to form a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of these. The permanent magnet 21a is composed of 32 poles, and the magnets of the N pole and the S pole are each made of magnetic metal in alternation with each other, and are divided into segments and have a linear shape. The arc centers of the inner diameter and the outer diameter are the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge at the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase the rust prevention and corrosion resistance after work forming and to prevent wear during bearing replacement.

Moreover, the 1st outer rotor 21 has the surface which fits and fixes the inner ring of the bearing 19, and the cylindrical member 23. As shown in FIG. The four-point contact ball bearing 19 is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the accuracy and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19, which is a rotating wheel, is easy to achieve the machining accuracy, and the gap is fitted to the yoke 21b having a linear expansion coefficient approximately equal to that of the bearing wheel material of the bearing without gaps or intermediate fittings. By loosely fitting the outer ring of the bearing 19 which is a fixed wheel to a bearing holder made of austenitic stainless steel or an boss made of aluminum, friction torque due to a decrease in the rotational accuracy of the bearing 19 and a temperature rise. It is a structure which prevents a raise.

In the radially inner side of the partition 13, the first stator 29 is disposed so as to face the inner circumferential surface of the first outer rotor 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, and is formed of a laminated material of an electromagnetic steel sheet, and each protrusion has an insulation treatment. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the first stator 29 is approximately equal to or smaller than the inner diameter of the partition 13.

The first inner rotor 30 is disposed in the radially inner side of the first stator 29. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 which is bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the first inner rotor 30, a permanent magnet 30a is attached via a back yoke 30b. Like the permanent magnet 21a of the first outer rotor 21, the permanent magnet 30a is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

As the detector for measuring the rotation angle on the inner circumference of the first inner rotor 30, the resolver rotors 34a and 34b are assembled, and on the outer circumference of the resolver holder 32 in a form opposite thereto, the resolver stators 35 and 36 In this embodiment, the high resolution incremental resolver stator 35 and the absolute resolver stator 36 capable of detecting which position of the rotor are located on the second floor are arranged in the second layer. For this reason, even when the power is turned on, the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known, thereby driving the direct drive motor D1. The rotation angle detection used for current control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36 which are angle detectors. Afterwards, chromate plating is performed to prevent rust .

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and the rotation axis and the outer peripheral surface of the incremental resolver stator 35 In parallel, a gear having a phase out of the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes and the incremental resolver rotor 34a In one rotation of), the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 40, and used as a position signal. The rotation angle (or rotation speed) of the resolver rotor 34a, that is, the first inner rotor 30 is detected. The detector is composed of resolver rotors 34a and 34b and resolver stators 35 and 36.

According to this embodiment, since the 1st inner rotor 30 rotates at the same speed, ie co-rotation, with respect to the 1st outer rotor 21 by a magnetic coupling action, The rotation angle can be detected over the partition wall 13. In the present embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the eccentric adjustment and the position of the resolver coil, etc., in the resolver unit are incorporated before being incorporated into the housing. Since precision can be adjusted, it is not necessary to separately provide adjustment holes and cutouts in the housing or both flanges. In addition, the rotor wheel of the bearing device 19 which rotatably supports the first outer rotor 21 is easy to achieve the machining precision, and the rotor yoke 21b having a linear expansion coefficient approximately equal to that of the drive wheel of the bearing device 19. It is possible to improve the rotational accuracy and to prevent the fluctuation of the frictional torque due to the temperature change by fitting in the.

Next, although direct drive motor D2 is demonstrated, the main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and the four-point contact ball bearing used in vacuum on the inner peripheral surface (2nd The outer ring of the bearing, 19 ') is fitted in a fitting manner, and is fixed by the bolt 20' via the annular bearing restraint BH '. On the other hand, the inner ring of the bearing 19 'is fitted to the outer circumference of the second outer rotor 21' and is fixed by the bolt 22 'via the annular bearing restraint BH'.

Here, the bolt 22 'and the magnetic shield plate 41 (illustrated by dotted lines) extending inward in the radial direction can be fixed at the same time. The second outer rotor 21 'is rotatably supported by the bearing 19' with respect to the cylindrical member 23 and the partition 13, and also has a ring-shaped member for supporting the arm A2 (Fig. 38). 23 'is fixed to the upper surface by the bolt 24'. In addition, the bolt 24 'fixes the magnetic shield plate 25' extending radially inward to the ring-shaped member 23 '. In this assembled state, the cylindrical member 23 'integrated with the second outer rotor 21' covers the bolt 20 'from the axial outward and the radial outward. The outer rotor is constituted by the second outer rotor 21 'and the cylindrical member 23'.

The magnetic shield plates 41 and 25 'can be nickel-plated in order to improve antirust and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The magnetic shield plates 41 and 25 'form a magnetic shield between the first outer rotor 21 and the second outer rotor 21', and mutually rotate together by missing magnetic flux therefrom. Has the function to prevent. That is, the magnetic shield plate 25 'is fastened to the yoke 21b' with the non-magnetic ring-shaped member 23 'interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated. Since the magnetic shield plates 41 and 25 'can prevent magnetic interference between the rotors, it is possible to configure a two-axis coaxial motor system with a reduced overall shaft length. The magnetic shield plate 41 can prevent foreign material suction from the outside.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the two-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

In addition, the bearing 19 'may be a metal lubrication with no outgassing in the vacuum by plating a soft metal such as gold or silver on the inner and outer rings, and is a four-point contact ball bearing. Although the moment in the direction in which the first outer rotor 21 'from the arm A1 is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used, and a preload state Or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The second outer rotor 21 'mechanically couples the ring-shaped yoke 21b' made of magnetic material to the permanent magnet 21a 'and the magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is comprised by the wedge (not shown) which consists of nonmagnetic bodies for this purpose. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles. The permanent magnets 21a' have a linear shape.扇形. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is toward the permanent magnet 21a ', and the permanent magnet 21a' is yoked (by screwing the wedge at the outer diameter side of the yoke 21b '). 21b '). With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel in order to increase corrosion resistance. The yoke 21b 'is made of a low-carbon steel having high magnetic properties, and nickel plating is applied to prevent rust and corrosion resistance and to prevent wear during bearing replacement after work forming.

Moreover, the 2nd outer rotor 21 'has the surface which fits and fixes the inner ring of the bearing 19', and the ring-shaped member 23 '. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly affected by the difference in the precision and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19 'is easy to achieve the machining accuracy, and the linear expansion coefficient is fitted to the yoke 21b, which is approximately the same as the track wheel material of the bearing, without gaps or intermediate fittings. The outer ring of the bearing 19 'is loosely fitted to an austenitic stainless steel bearing holder or an aluminum boss to reduce the rotational accuracy of the bearing 19' and to increase the friction torque due to the temperature rise. It is made of a blocking structure.

In the radially inner side of the partition wall 13, the 2nd stator 29 'is arrange | positioned so that it may oppose the inner peripheral surface of the 2nd outer rotor 21'. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 30 'is disposed in the radially inner side of the second stator 29'. The second inner rotor 30 ′ is rotatably supported by the ball bearing 33 ′ against the resolver holder 32 ′ bolted to the outer circumferential surface of the main body 12. On the outer circumferential surface of the second inner rotor 30 ', a permanent magnet 30a' is mounted via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Therefore, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the first inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet (30a ') is a high energy neodymium (Nd-Fe-B) -based magnet, and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a 'and 34b' are assembled on the inner circumference of the second inner rotor 30 ', and the resolver stator 35 is disposed on the outer circumference of the resolver holder 32' in a form opposite thereto. In the present embodiment, the high resolution incremental resolver stator 35 'and the absolute resolver stator 36' capable of detecting where the rotor is located at one rotation are 2 in this embodiment. Placed on the floor. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b 'can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The detection of the relative rotation angle of is possible without using the pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of magnetic carbon steel as a material so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 30 'rotates at the same speed, ie co-rotation, with respect to the 2nd outer rotor 21' by a magnetic coupling action, the 2nd outer rotor 21 is carried out. The rotation angle of ') can be detected over the partition wall 13. In this embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the precision such as eccentricity adjustment and the position of the resolver coil in the resolver unit is incorporated before being incorporated into the housing. Since adjustment can be performed, it is not necessary to provide a hole or cutout for adjustment separately in a housing or both flanges. In addition, the rotor wheel of the bearing device 19 'which rotatably supports the second outer rotor 21' is easy to achieve the machining precision, and the rotor yoke (coefficient of linear expansion approximately equal to that of the drive wheel of the bearing device 19 ') 21b '), it is possible to improve the rotational accuracy and to prevent the friction torque from changing due to temperature change.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and is provided on the outer circumferential surface of the incremental resolver stator 35'. A gear having a phase out of the incremental resolver rotor 34a 'at each magnetic pole is provided in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the second inner rotor 30', the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 'changes and the incremental resolver In one rotation of the rotor 34a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 40, and used as a position signal. The rotational angle (or rotational speed) of the elemental resolver rotor 34a ', that is, the second inner rotor 30' is detected. The detector is composed of resolver rotors 34a 'and 34b' and resolver stators 35 'and 36'.

According to this embodiment, the magnetic shield plates 25 and 41 are arrange | positioned between the 1st outer rotor 21 and the 2nd outer rotor 21 ', and mutual magnetic interference is suppressed and a misdrive is performed. And inconvenience such as accompanying rotation can be avoided. Moreover, the outer periphery 12b of the flange part 12a which extends between the direct drive motors D1 and D2 in the main body 12 is made of carbon steel that is a magnetic material, and the first stator 29 and the second stator ( 29 ') and interfering with each other's magnetic fields so that they are affected by the missing magnetic flux so that the first outer rotor 21 or the second outer rotor 21' does not generate a thrust in the wrong rotational direction. Function as a magnetic shield.

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned inside the radial direction. The main body 12 has a hollow structure, and the flange portion 12a is provided with at least one radial guide hole 12d in communication with the center, and through this, the motor wiring is connected to the center of the main body 12. It is structured to draw out. On the other hand, at least one notch 12e, 12e is provided in the both ends of the main body 12, respectively, and it has a structure which draws the resolver wiring to the center of the main body 12 via these. With such a structure, it becomes possible to arrange | position in the order of the resolver of the direct motor D1, the stator 29, the stator 29 'of the direct motor D2, and the resolver in order from a housing side, 2 The angle of the stator and resolver can be easily adjusted while being an axis. Therefore, by separately preparing a facility for rotationally driving the outer rotor as a reference, the main body 12 incorporating the stator and the resolver is set in the facility so that the angle of the resolver with respect to the stator can be adjusted with high accuracy. The fall of the angular positioning precision by the difference of a tation can be prevented, and the compatibility of the drive control circuit with respect to the 2-axis coaxial motor of this invention can be improved.

Fig. 41 is a block diagram showing the drive circuit of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D1 and D2 from the three-layer amplifier AMP. As a result, the outer rotors 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1, A2, and FIG. When the outer rotors 21 and 21 'rotate, a resolver signal is output from the resolver stators 35, 36, 35', and 36 'that have detected the rotation angle as described above, so that the resolver digital converter RDC is output. The CPU input after the digital conversion determines whether the outer rotors 21 and 21 'have reached the command position, and when the command position reaches the command position, the outer rotor 21 is stopped by stopping the drive signal to the three-layer amplifier AMP. , 21 ') is stopped. This enables servo control of the outer rotors 21 and 21 '.

In the case of driving a plurality of arms in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In the present embodiment, a variable magnetoresistance comprising an absolute resolver stator 36 and 36 'for detecting an absolute position of one rotation of the rotary shaft, and an incremental resolver stator 35 and 35' for detecting a finer rotational position with a higher resolution. Since the type resolver is adopted, the rotational position control of the outer rotors 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 30 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, generally, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

Next, the disassembly shape of the motor system which concerns on this embodiment is demonstrated. 42-45 is sectional drawing which shows the disassembly process of the motor system which concerns on this embodiment, and FIGS. 46-49 are perspective views which show the disassembly process of the motor system which concerns on this embodiment.

In the motor system according to the present embodiment, it is assumed that the inspection or replacement of the bearing 19 of the direct drive motor D1 is required. In this case, a tool (not shown) is engaged with the hexagonal bolt 18 where the head is exposed, thereby alleviating this. Then, as shown in FIG. 42, since the bearing holder 17 can be isolate | separated from the original plate 10, direct drive motors D1 and D2 can be pulled out integrally (refer FIG. 46). Here, since the partition 13 and the original plate 10 can be assembled, the airtightness does not decay, and it is not necessary to perform a leak check etc. at the time of reassembly.

At this time, since the lower surface of the direct drive motor D1 is exposed, the lubrication state of the bearing 19 can be checked. When it is judged that the bearing 19 has reached the replacement time by such a check, the bearing 19 needs to be replaced.

When the bearing 19 is replaced, as shown in FIG. 43, the bolt 22 is removed from the yoke 21b (see FIG. 47). Then, since the bearing restraint BH which fixed the inner ring of the bearing 19 can be isolate | separated, as shown in FIG. 44, the bearing 19 can be detached integrally with the bearing holder 17 (FIG. 48).

In this state, if the bolt 20 is removed from the bearing holder 17, the bearing restraint BH which has fixed the outer ring of the bearing 19 can be separated, so that the bearing 19 is removed from the bearing holder 17. Can be separated. The granulation may be performed in the above and reverse order.

When the bearing 19 'of the direct drive motor D2 needs to be inspected or replaced, the cylindrical member 23' is removed by removing the bolt 24 'from the yoke 21b' in FIG. It can be removed. At this time, since the bearing 19 'can be visually recognized, the lubrication state etc. can be checked.

When it is judged that the bearing 19 'is due to such a check, when the bolt 20' is removed from the cylindrical member 23, the bearing restraint BH 'which fixed the outer ring of the bearing 19' is fixed. ), The bearing 19 'can be separated integrally with the yoke 21b'.

In addition, when the bolt 22 'is removed from the yoke 21b', the bearing restraint BH 'which fixed the inner ring of the bearing 19 can be separated, and therefore, the bearing 19' from the yoke 21b '. Can be separated. The granulation may be performed in the above and reverse order. 45 and 12 show a state in which the direct drive motors D1 and D2 are completely disassembled.

According to this embodiment, the minimum inner diameter of the 1st outer rotor 21 of the direct drive motor D1 and the 2nd outer rotor 21 'of the direct drive motor D2 is larger than the maximum outer diameter of the partition 13, Further, the yoke 21b of the direct drive motor D1 is attached to the disc 10 by the bolt 18 via the bearing holder 17, and furthermore, the cylindrical member 23 of the direct drive motor D1. The yoke 21b 'of the direct drive motor D2 is attached to the direct drive motor D2 via the bearing 19', so that the direct drive motors D1 and D2 are removed for each bearing holder 17 by removing the bolt 18. It is separable from the original plate 10 and the partition 13, and it is not necessary to disassemble the airtight structure by the partition 13, and maintenance work of the direct drive motor D1 can be performed easily.

50 is a cross-sectional view showing a four-axis coaxial motor system according to a modification of the present embodiment. In the modification shown in FIG. 50, although the direct drive motors D1 and D2 are directly arranged in two sets (four in total), the individual direct drive motors are the same as the configuration shown in FIG. The same code | symbol is attached | subjected to a main component, and description is abbreviate | omitted.

In this embodiment, the partition holder 113a is hermetically coupled to the upper disc part 110 attached to the upper surface of the main body 12 connected in series via an O-ring OR, and a thin cylinder is formed on the outer circumferential surface thereof. The upper end of the 113b is made by TIG welding. The lower end of the thin cylinder 113b is TIG-welded to the holder 15 similarly to embodiment mentioned above. The partition wall is constituted by the partition wall holder 113a, the thin cylinder 113b, and the holder 15, but this is commonly used for four direct drive motors.

The upper surface of the disc part 110 is closed by the cover member 101, and the bearing holder 107 attached to the outer periphery supports the bearing 19. As shown in FIG. The disc part 110, the cover member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance. The housing is constituted by the main body 12, the disc 10, and the upper disc part 110.

In the lower direct drive motors D1 and D2, a separate bearing holder 17 is fixed to the outer circumferential upper surface of the disc 10, which is an atmospheric outer member, by a bolt 18. The first outer rotor 21 is supported by the bearing 19 with respect to the bearing holder 17. The second outer rotor 21 ′ is supported by the bearing 19 ′ against the cylindrical member 23.

On the other hand, in the upper direct drive motors D1 and D2, the bearing holder 107 is fixed by the bolt 118 to the outer circumferential upper surface of the upper disc portion 110 which is the atmospheric outer member. The first outer rotor 21 is supported by the bearing 19 with respect to the bearing holder 17. The second outer rotor 21 ′ is supported by the bearing 19 ′ against the first outer rotor 21.

The minimum inner diameter of the first outer rotor 21 of the direct drive motor D1 and the second outer rotor 21 'of the direct drive motor D2 is larger than the maximum outer diameter of the partition 13, and the upper disc The attaching outer circumferential surface of the bearing holder 107 of the separate body of the part 110 is located radially inward than the thin cylinder 113b, and therefore, when the bearing holder 107 is removed from the upper disc part 110, the upper two The outer rotors 21 and 21 'can be pulled out without disassembling the upper disc part 110, In addition, when the bearing holder 17 is removed from the disc 10, the lower two outer rotors 21 and 21 'can also be pulled out upward without disassembling the upper disc part 110. FIG. Therefore, it is not necessary to dismantle the airtight structure by the partition 13 at the time of maintenance, such as inspection of a bearing, replacement | exchange, etc., and maintenance work can be made easy.

In this embodiment, since magnetic shield plates 25 'and 25' are arrange | positioned between 2nd outer rotor 21 'and 21' of the center, mutual magnetic interference is suppressed and a misdrive and Discomforts such as accompanying rotations are avoided. Moreover, between the main bodies 12 and 12, the magnetic shield plate 125 extended in the radial direction is arrange | positioned from the outer periphery to the inside of the thin cylinder 113b. The magnetic shield plate 125 is made of carbon steel, which is a magnetic material, and is interposed between the second stators 29 ', 29', and is adjacent to the second outer rotors 21 ', 21 affected by the missing magnetic flux. It acts as a magnetic shield to block each other's magnetic fields so as not to generate thrust in the wrong rotational direction. In this manner, a configuration in which the entire axial length is suppressed while being four axes coaxial with the effects of the other magnetic shields 25, 41 and 12b is possible.

51 is a perspective view of a frog leg female conveying apparatus using the four-axis coaxial motor system according to the present embodiment. In FIG. 51, the 1st arm A1 is connected to the rotor of each direct drive motor D1, and the 1st link L1 is pivotally connected to the front-end | tip of the 1st arm A1. On the other hand, the second arm A2 is connected to the rotor of each direct drive motor D2, and the second link L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed. Each table T moves independently of each other.

In the above embodiment, a surface magnet type 32 pole 36 slot out rotor type brushless motor has been described using an example. However, the present invention is not limited to this type of motor and can be applied to a brushless motor. It may be a type, for example, a permanent magnet embedded type, another slot combination, or an inner rotor type.

In addition, as a countermeasure for each axis, the number of poles and the number of slots of the rotors adjacent to each other in the axial direction may be different. For example, in the case of biaxial coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4 axes coaxials, the first and third axes are 32 poles 36 slots and the second axis. When the fourth axis has a configuration of 24 poles and 27 slots, mutual interference such as thrust generation in the rotational direction of the rotor and the magnetic coupling device due to the magnetic field of each axis can be prevented.

In addition, although the permanent magnet of the rotor was explained using a nickel coating as a coating for enhancing corrosion resistance using a neodymium (Nd-Fe-B) magnet, the material is not limited to this material and surface treatment. It is appropriately changed according to the environment and the like. For example, a samarium cobalt (Sm Co) magnet that is difficult to be hot potato depending on the temperature conditions at the time of baking out should be used. Titanium nitride coating with high gas barrier properties should be applied.

In addition, although the yoke was demonstrated using the example which made low carbon steel the material and performed nickel plating, it is not limited to this material and surface treatment, It changes suitably by the environment etc. used, Especially about surface treatment If it is used in a vacuum, it is necessary to carry out Carnizen plating, clean S plating, titanium nitride coating, etc., with less pinholes.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed from the outer diameter side of the yoke, but it is appropriately changed according to the environment used, and may be suitable for adhesion depending on the environment. Also good for.

In addition, although the bearings 19 and 19 'demonstrated the example using the four-point contact ball bearing of vacuum grease lubrication, it is not limited to this form, material, and lubrication method, but it depends on the environment used, load conditions, rotation speed, etc. It may be appropriately changed, and may be a cross roller bearing, or in the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, it may be a structure supported by a separate bearing, or a multi-point contact bearing such as when rotating at high speed. If not available, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings. It is also possible to use a metal lubrication without gas discharge, such as plating a soft metal.

In addition, although it demonstrated in the form which used a permanent magnet and a back yoke as an inner rotor which functions as a magnetic coupling, the material and shape of a permanent magnet and a back yoke are not limited to this. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the outer rotor or may not be the same width. It is also good for rushes that do not use permanent magnets.

Moreover, although the example which used the resolver as an angle detector was demonstrated, it changes suitably by manufacturing cost or resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33 and 33 'rotatably supporting the rotation side of an angle detector, it is not limited to this type and a lubrication method, but it is installation space and friction If the multi-point contact bearing is not available, such as high speed rotation or reduction of friction torque, two angular bearings or deep groove ball bearings are arranged on each axis and preloaded. You may make it.

In addition, the materials, shapes, and manufacturing methods of the structural parts and the partitions arranged outside and inside the other partitions are appropriately changed depending on the production cost, the environment used, the load conditions, and the configuration.

The above-described motor system is mutually prevented from generating a thrust in the rotational direction by the magnetic flux leaking from the rotor, the stator, or the magnetic coupling used in the resolver, for each of the shafts. A magnetic shield for shielding a magnetic field is provided between the rotors of each axis, or a magnetic shield for shielding each other's electromagnetic fields is prevented from interfering with each other's resolvers by the electromagnetic fields generated from the rotor, the stator, and the resolver of each axis, By changing the number of poles of the rotor and the number of slots of the stator between the axes adjacent to each other in the axial direction, magnetic interference between each axis is prevented, so the axial length of each axis and the axial distance of each axis You can shorten it. Therefore, the structure which restrained the whole shaft length while being a multi-axis coaxial motor system called two-axis coaxial and four-axis coaxial is possible. In particular, in a system using a direct drive motor with a multi-axis configuration called 4-axis coaxial, two prog leg female robots can be installed, which can accurately position the chamber without greatly changing the chamber structure. Improve performance and uptime.

As mentioned above, although this invention was demonstrated with reference to embodiment, it cannot be overemphasized that this invention is limited to the said embodiment, Of course, it can change and improve suitably. For example, the direct drive motor of the present embodiment can be used not only in a vacuum atmosphere but also in an atmosphere outside the atmosphere. For example, in the semiconductor manufacturing process, the reactive gas for etching may be introduced into the vacuum chamber after vacuum evacuation. However, in the direct drive motor of the present embodiment, since the inside and the outside are shielded by the partition wall, the motor There is no fear that the coil or the insulating material may be etched.

[Seventh embodiment]

EMBODIMENT OF THE INVENTION Next, embodiment of this invention is described with reference to drawings. 52 is a perspective view of a frog leg female conveying apparatus using the direct drive motor according to the present embodiment. In Fig. 52, two direct drive motors D1 and D2 are connected in series. The first arm A1 is connected to the rotor of the lower direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1. On the other hand, the second arm A2 is connected to the rotor of the upper direct drive motor D2, and the second link L2 is pivotally connected to the tip of the second arm A2. The links L1 and L2 are pivotably connected to the table T on which the wafers W are placed.

As apparent from Fig. 52, when the rotors of the direct drive motors D1 and D2 rotate in the same direction, the table T also rotates in the same direction, and when the rotor rotates in the reverse direction, the table T is a direct drive. The motors D1 and D2 are approached or spaced apart. Therefore, if the direct drive motors D1 and D2 are rotated at any angle, the wafer W can be transported to any two-dimensional position within the range in which the table T touches.

In this way, for example, in a device having a plurality of arms such as a wafer transfer arm disposed in a vacuum chamber in a semiconductor manufacturing apparatus, for example, a scalar type or a frog leg type shown in the drawing, A plurality of rotary motors is needed. In a vacuum environment, it is necessary to make the contact surface area with the outside world as small as possible, and in order to utilize the space effectively, the attachment holes of the motor and the like should be as small as possible. In addition, in order to convey the wafer W horizontally straight with the least vibration, it is necessary to firmly protect and maintain the moment acting on the tip of the arm at the rotor support. Thus, a plurality of direct drive motors D1 and D2 are coaxially connected in the housing part, and the connecting part is tightly joined by a seal (dense joint by welding, O-ring, metal gasket, etc.), and the installed space of the motor rotor. It is also necessary to space the space outside the housing.

Moreover, in order to convey the wafer W horizontally straight and with less vibration, it is necessary to firmly protect and hold the moment which acts on the front-end | tip of arm A1, A2 at the rotor support part. In addition, in the case of arm drive of a plurality of axes in a vacuum environment, if the current rotation position of the arm is not recognized at the time of power supply, the arms A1 and A2 may hit the walls of the vacuum chamber or the shutter of the vacuum chamber. A motor system that coaxially connects a direct drive motor capable of meeting these demands will be described.

This embodiment uses the surface magnet type 32 pole 36 slot out rotor type brushless direct drive motor. The slot combination, called 32-pole 36 slot, has four times the configuration of a slot combination of 8-pole 9-slot, which is generally known to have a small cogging force but generate magnetic attraction force in the radial direction and a large vibration during rotation. Since the magnetic attraction force in the radial direction is canceled out by 2 ⁿ times (n is an integer), the vibration at the time of rotation can be reduced without increasing the roundness, coaxiality of the stator and the rotor, and the rigidity of the mechanical parts, In addition, since cogging is inherently small, a very smooth rotation can be obtained. On the other hand, as such a motor having many poles, since the period of the electric angle with respect to the period of the machine angle is large, the positioning controllability is good. Therefore, like the present invention, it is very suitable for a direct drive motor such as driving a robot apparatus without using a speed reducer. In addition, since the thickness, protrusion width, and yoke thickness of the rotor can be narrowed without lowering the total magnetic flux amount, it is very suitable for a thin, large diameter and narrow direct drive motor as in the present invention.

FIG. 53 is a view of the configuration of FIG. 52 taken along line II-II and viewed in the direction of the arrow. With reference to FIG. 53, the internal structure of a two-axis motor system is demonstrated in detail. First, the direct drive motor D1 will be described. The hollow cylindrical bodies 12 fixed to each other by bolts 11 fitted to the central opening 10a of the disc 10 fixed to the surface plate G have a cup-shaped partition 13 attached to the upper end thereof. have. The center of the main body 12 can be used in order to communicate with wiring to the stator. The main body 12 and the disc 10 comprise a housing.

The partition wall 13 is made of stainless steel, which is a nonmagnetic material, and has a bottom portion 13a having a thickness to fit the main body 12, and a thin cylinder extending through the direct drive motors D1 and D2 in the axial direction from its outer circumference. It consists of a part 13b and the holder 15. Therefore, the partition 13 is commonly used for the direct drive motors D1 and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 by bolts 16. Here, the welded portions of the cylindrical portion 13b and the holder 15 are made to have approximately the same thickness, and the structure is such that the heat escapes only to the components on one side, and the fitting portion can be welded uniformly. The contact surface between the holder 15 and the disc 10 is grooved to fit the seal member. After the seal member OR is inserted into the groove, the holder 15 and the disc 10 are attached to the bolt 16. By tightening, the fastening portion is separated and separated from the atmosphere side. The partition 13 is made of SUS 316 made of austenitic stainless steel having high corrosion resistance, particularly low magnetic properties, and the holder 15 is made of SUS 316 similarly in weldability with the partition 13.

In addition, the partition 13 and the holder 15 are hermetically bonded, and the holder 15 and the disc 10, and the disc 10 and the surface plate G are respectively sealed by an O-ring OR. . Therefore, the inner space surrounded by the disc 10 and the partition 13 is hermetically sealed from the outside. In addition, the partition 13 does not necessarily need to be a nonmagnetic material. In place of hermetically using the O-ring OR, the members may be hermetically sealed by electron beam welding, laser beam welding, or the like.

On the outer circumferential upper surface of the disc 10, the bearing holder 17 is fixed by the bolt 18. As shown in FIG. The outer ring of the four-point contact ball bearing 19 used in a vacuum is fitted to the bearing holder 17, and is fixed by the bolt 20. As shown in FIG. On the other hand, the inner ring of the bearing 19 is fitted to the outer circumference of the first outer rotor 21 and is fixed by the bolt 22. That is, the 1st outer rotor 21 is rotatably supported with respect to the partition 13, and the cylindrical member 23 which supports the arm A1 (FIG. 52) is fixed by the bolt 24. As shown in FIG. Here, the bolt 24 simultaneously fixes the magnetic shield plate 25 extending radially inwardly to the cylindrical member 23.

The disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance, and the disc 10 also serves as a fitting and sealing device with the base plate G, which is a chamber, and the bottom surface thereof. The groove 10b which fits the O-ring OR is provided in this.

The magnetic shield plate 25 is nickel-plated in order to improve antirust and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The effect is mentioned later.

The bearing 19 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D1 ends with one, the two-axis coaxial motor system of the present invention can be thinned. The bearing 19 is made of a martensitic stainless steel that has high corrosion resistance in both inner and outer rings and can be hardened by quenching. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum. Doing.

In addition, the bearing 19 may use metal lubrication which plate | plates soft metals, such as gold and silver, in the inner ring and outer ring, and has no outgas discharge | emission even in vacuum, and is a four-point contact ball bearing, Although the moment in the direction in which the first outer rotor 21 from (A1) tilts can be received, not only the four-point contact type but also cross rollers, cross balls, and cross taper bearings can be used, and are used in a preload state. In order to improve lubricity, a fluorine-based coating treatment (DFO) may be performed.

The first outer rotor 21 is a ring-shaped yoke 21b made of a magnetic material to form a permanent magnet 21a and a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is comprised by the wedge (not shown) which consists of. The permanent magnet 21a has a 32-pole configuration, and magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles, and are divided into segments and have a linear shape. The arc centers of the inner diameter and the outer diameter are the same, but the tangential intersection of the circumferential end faces toward the permanent magnet 21a, and the permanent magnet 21a is screwed on the yoke 21b by screwing the wedge at the outer diameter side of the yoke 21b. Fastening. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to increase corrosion resistance. The yoke 21b is made of low carbon steel having high magnetic properties, and is nickel-plated in order to increase corrosion resistance and corrosion resistance after work forming and to prevent wear during bearing replacement.

Moreover, the 1st outer rotor 21 has the surface which fits and fixes the inner ring of the bearing 19, and the cylindrical member 23. As shown in FIG. The four-point contact ball bearing 19 is a very thin bearing, and rotational precision and friction torque are greatly influenced by the difference in the accuracy and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19, which is a rotating wheel, is easily fitted to the yoke 21b, which has an easy processing accuracy, and whose linear expansion coefficient is approximately the same as that of the track wheel material of the bearing, or is intermediate. By loosely fitting the outer ring of the bearing 19, which is a fixed wheel, to the bearing holder made of austenitic stainless steel or the boss made of aluminum, friction torque due to a decrease in the rotational accuracy of the bearing 19 or an increase in temperature. It is a structure which prevents a raise.

In the radially inner side of the partition 13, the first stator 29 is disposed to face the inner circumferential surface of the first outer rotor 21. The first stator 29 is attached to a cylindrically deformed lower portion of the flange portion 12a extending radially from the center of the main body 12, and is formed of a laminated material of an electromagnetic steel sheet, and is provided as an insulating treatment on each protrusion. After the bobbin is inserted, the motor coil is concentrated. The outer diameter of the first stator 29 is approximately equal to or smaller than the inner diameter of the partition 13.

The first inner rotor 30 is disposed in the radially inner side of the first stator 29. The first inner rotor 30 is rotatably supported by the ball bearing 33 with respect to the resolver holder 32 which is bolted to the outer circumferential surface of the main body 12. The permanent magnet 30a is mounted on the outer circumferential surface of the first inner rotor 30 via the back yoke 30b. The permanent magnet 30a has a 32-pole configuration similar to the permanent magnet 21a of the first outer rotor 21, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Accordingly, the first inner rotor 30 is co-rotated in synchronization with the first outer rotor 21 driven by the first stator 29.

The bearing 33 rotatably supporting the first inner rotor 30 is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D1 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a is adhesively fixed to the back yoke 30b. The permanent magnet 30a is an energy-efficient neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b is made of low carbon steel having high magnetic properties and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a and 34b are assembled on the inner circumference of the first inner rotor 30, and the resolver stators 35 and 36 are disposed on the outer circumference of the resolver holder 32 in a form opposite thereto. Although attached, in this embodiment, the high resolution incremental resolver stator 35 and the absolute resolver stator 36 which can detect which position of a rotor exist in one rotation are arrange | positioned on the 2nd floor. Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b can be known, the zero point return is unnecessary, and the electrical phase angle of the magnet with respect to the coil can be known. The rotation angle detection used for drive current control is enabled without using a pole detection sensor.

The resolver holder 32 and the first inner rotor 30 are formed of carbon steel, which is a magnetic material, so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 and 36 which are angle detectors. Later, chromate plating is performed for rust prevention.

In the high-resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a has a plurality of slot teeth having a constant pitch, and the rotation axis and the outer peripheral surface of the incremental resolver stator 35 In parallel, a gear having a phase out of the incremental resolver rotor 34a is provided at each magnetic pole, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a rotates integrally with the first inner rotor 30, the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 changes, and the incremental resolver rotor 34a In one rotation of, the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 54, and used as a position signal. The rotation angle (or rotation speed) of the resolver rotor 34a, that is, the first inner rotor 30 is detected. The detector is composed of resolver rotors 34a and 34b and resolver stators 35 and 36.

According to this embodiment, since the 1st inner rotor 30 rotates at the same speed, ie co-rotation, with respect to the 1st outer rotor 21 by a magnetic coupling action, The rotation angle can be detected over the partition wall 13. In this embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the precision such as eccentricity adjustment and the position of the resolver coil in the resolver unit is incorporated before being incorporated into the housing. Since adjustment can be performed, it is not necessary to provide a hole or cutout for adjustment separately in a housing or both flanges. In addition, the rotating wheels of the bearing device 19 which rotatably supports the first outer rotor 21 are easy to achieve the machining accuracy, and the coefficient of linear expansion is applied to the rotor yoke 21b which is approximately the same as the drive wheel of the bearing device 19. By fitting, the rotational accuracy can be improved and the frictional torque caused by temperature change can be prevented.

Next, although direct drive motor D2 is demonstrated, the main body 12 comprises a housing here. The cylindrical member 23 of the above-mentioned direct drive motor D1 extends upwards to the position to superpose | polymerize with the direct drive motor D2, and the 4-point contact ball bearing 19 'used in vacuum on the inner peripheral surface The outer ring is fitted in a fitting manner and is fixed by bolts 20 '. On the other hand, the inner ring of the bearing 19 'is fitted to the outer circumference of the second outer rotor 21' and is fixed by the bolt 22 '. Here, the bolt 22 'and the magnetic shield plate 41 extending inward in the radial direction are simultaneously fixed. The second outer rotor 21 'is rotatably supported with respect to the partition wall 13, and the ring-shaped member 23' supporting the arm A2 (Fig. 52) is fixed by the bolt 24 '. have. In addition, the bolt 24 'fixes the magnetic shield plate 25' extending radially inward to the ring-shaped member 23 '.

The magnetic shield plates 41 and 25 'are nickel-plated in order to improve the rust prevention and corrosion resistance after press molding a SPCC steel plate which is a magnetic body. The magnetic shield plates 41 and 25 'form a magnetic shield between the first outer rotor 21 and the second outer rotor 21', and mutually rotate together by missing magnetic flux therefrom. Is preventing. That is, the magnetic shield plate 25 'is fastened to the yoke 21b' with the non-magnetic ring-shaped member 23 'interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated. Since the magnetic shield plates 41 and 25 'can prevent magnetic interference between the rotors, it is possible to configure a two-axis coaxial motor system with a reduced overall shaft length. The magnetic shield plate 41 prevents foreign material suction from the outside.

The bearing 19 'is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since the bearing of the direct drive motor D2 ends with one, the two-axis coaxial motor of the present invention can be thinned. Both inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by hardening. The rolling element uses ceramic grease and a vacuum grease that does not solidify even in vacuum.

In addition, the bearing 19 'may be made by plating a soft metal such as gold or silver on the inner ring and the outer ring, and using metal lubrication without outgas discharge even in vacuum. Although the moment in the direction in which the first outer rotor 21 'from the arm A1 is tilted can be received, not only the four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used, and a preload state Or a fluorine-based coating treatment (DFO) may be performed to improve lubricity.

The second outer rotor 21 'mechanically fixes the permanent magnet 21a', a ring-shaped yoke 21b 'made of a magnetic body to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is comprised by the wedge (not shown) which consists of a nonmagnetic body for fastening. The permanent magnet 21a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternating manner with each of 16 magnetic poles. The permanent magnet 21a' is divided into poles, and the individual shapes thereof are linear. )to be. The arc center of the inner diameter and the outer diameter is the same, but the tangential intersection of the circumferential cross section is directed toward the permanent magnet 21a ', and the permanent magnet 21a' is screwed by screwing the wedge at the outer diameter side of the yoke 21b '. 21b '). With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas such as an adhesive. The permanent magnet 21a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel in order to increase corrosion resistance. The yoke 21b 'is made of a low-carbon steel having high magnetic properties, and nickel plating is applied to prevent rust and corrosion resistance and to prevent wear during bearing replacement after work forming.

Moreover, the 2nd outer rotor 21 'has the surface which fits and fixes the inner ring of the bearing 19', and the ring-shaped member 23 '. The four-point contact ball bearing 19 'is a very thin bearing, and rotational precision and friction torque are greatly affected by the difference in the precision and linear expansion coefficient of the assembling member. Therefore, in the present embodiment, the inner ring of the bearing 19 'is easy to achieve the machining accuracy, and the linear expansion coefficient is fitted to the yoke 21b, which is approximately the same as the track wheel material of the bearing, without gaps or intermediate fittings. The outer ring of the bearing 19 'is loosely fitted to an austenitic stainless steel bearing holder or an aluminum boss to reduce the rotational accuracy of the bearing 19' and to increase the friction torque due to the temperature rise. It is configured to prevent this.

In the radially inner side of the partition 13, the second stator 29 ′ is disposed to face the inner circumferential surface of the second outer rotor 21 ′. The second stator 29 'is attached to a cylindrically deformed upper portion of the flange portion 12a extending radially from the center of the main body 12, formed of a laminated material of an electromagnetic steel sheet, and insulated on each protrusion. After the bobbin is inserted, the motor coil is intensively wound. The outer diameter of the second stator 29 'is approximately equal to or smaller than the inner diameter of the partition 13.

The second inner rotor 30 'is disposed in the radially inner side of the second stator 29'. The second inner rotor 30 ′ is rotatably supported by the ball bearing 33 ′ against the resolver holder 32 ′ bolted to the outer circumferential surface of the main body 12. A permanent magnet 30a 'is attached to the outer circumferential surface of the second inner rotor 30' via a back yoke 30b '. Like the permanent magnet 21a 'of the second outer rotor 21', the permanent magnet 30a 'is composed of 32 poles, and the magnets of the N pole and the S pole are made of magnetic metal in alternation with each of 16 pieces. Therefore, the second inner rotor 30 'is driven to rotate in synchronization with the second outer rotor 21' by the second stator 29 '.

The bearing 33 'rotatably supporting the first inner rotor 30' is a four-point contact ball bearing capable of loading radial, axial and moment loads into one bearing. By using this type of bearing, since it ends with one bearing, the direct drive motor D2 can be thinned. Since the inside of the partition 13 is an atmospheric environment, the bearing using grease lubrication based on general bearing steel and mineral oil can be applied.

Since the inside of the partition 13 is an atmospheric environment, the permanent magnet 30a 'is adhesively fixed to the back yoke 30b'. The permanent magnet 30a 'is an energetic neodymium (Nd-Fe-B) magnet and is coated with nickel to prevent demagnetization due to rust. The yoke 30b 'is made of low carbon steel having high magnetic properties, and is subjected to chromate plating for rust prevention after work forming.

Resolver rotors 34a 'and 34b' are assembled on the inner circumference of the second inner rotor 30 ', and the resolver stator 35 is disposed on the outer circumference of the resolver holder 32' in a form opposite thereto. 36 '), but in the present embodiment, the high resolution incremental resolver stator 35' is provided with two layers of the absolute resolver stator 36 'capable of detecting the position of the rotor in one rotation. Posted in Therefore, even when the power is turned on, since the rotation angle of the absolute resolver rotor 34b 'can be known, the origin return is not necessary, and the electrical phase angle of the magnet with respect to the coil can be known, so that the direct drive motor D2 can be obtained. The detection of the relative rotation angle of is possible without using the pole detection sensor.

The resolver holder 32 'and the second inner rotor 30' are made of magnetic carbon steel as a material so that electromagnetic noise from the field and the motor coil of the motor is not transmitted to the resolver stators 35 'and 36' which are angle detectors. And chromate plating is performed for rust prevention after work forming.

According to this embodiment, since the 2nd inner rotor 30 'rotates at the same speed, ie co-rotation, with respect to the 2nd outer rotor 21' by a magnetic coupling action, the 2nd outer rotor 21 is carried out. The rotation angle of ') can be detected over the partition wall 13. In this embodiment, the bearing 33 is formed by the resolver unit alone without using a component or a housing forming a motor. Therefore, the precision such as eccentricity adjustment and the position of the resolver coil in the resolver unit is incorporated before being incorporated into the housing. Since adjustment can be performed, it is not necessary to provide a hole or cutout for adjustment separately in a housing or both flanges. In addition, the rotor wheel of the bearing device 19 'which rotatably supports the second outer rotor 21' is easy to achieve the machining precision, and the rotor yoke (coefficient of linear expansion approximately equal to that of the drive wheel of the bearing device 19 ') 21b '), it is possible to improve the rotational accuracy and to prevent the friction torque from changing due to temperature change.

In the high resolution variable magnetoresistive resolver used in the present embodiment, the incremental resolver rotor 34a 'has a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35'. The gears which are out of phase with respect to the incremental resolver rotor 34a 'at each magnetic pole are provided in parallel with the axis of rotation, and a coil is wound around each magnetic pole. When the incremental resolver rotor 34a 'rotates integrally with the second inner rotor 30', the magnetic resistance between the magnetic resolver of the incremental resolver stator 35 'changes and the incremental resolver In one rotation of the rotor 34a ', the fundamental wave component of the magnetoresistance change is n periods, the magnetoresistance change is detected, digitized by the resolver control circuit illustrated in FIG. 54, and used as a position signal. The rotational angle (or rotational speed) of the elemental resolver rotor 34a ', that is, the second inner rotor 30' is detected. The detector is composed of resolver rotors 34a 'and 34b' and resolver stators 35 'and 36'.

According to this embodiment, since the magnetic shield plates 25 and 41 are arrange | positioned between the 1st outer rotor 21 and the 2nd outer rotor 21 ', mutual magnetic interference is suppressed and a misdrive is performed. And inconvenience such as companion rotation is avoided. In addition The outer periphery 12b of the flange portion 12a extending between the direct drive motors D1 and D2 with respect to the main body 12 is made of carbon steel, which is a magnetic material, and the first stator 29 and the second stator ( 29 ') and interfering with each other's magnetic fields so that they are affected by the missing magnetic flux so that the first outer rotor 21 or the second outer rotor 21' does not generate a thrust in the wrong rotational direction. Function as a magnetic shield.

Moreover, the 1st stator 29 and the 2nd stator 29 'are arrange | positioned up and down centering on the flange part 12a, and the resolver is arrange | positioned inside the radial direction. The main body 12 has a hollow structure, and the flange portion 12a is provided with at least one radial guide hole 12d in communication with the center, and the motor wiring is provided at the center of the main body 12 through the flange 12a. It is structured to draw out. On the other hand, at least one notch 12e, 12e is provided in the both ends of the main body 12, and it has a structure which draws the resolver wiring to the center of the main body 12 via these. With such a structure, it becomes possible to arrange | position in the order of the resolver of the direct motor D1, the stator 29, the stator 29 'of the direct motor D2, and the resolver in order from a housing side, The angle of the stator and resolver can be easily adjusted. Therefore, by separately preparing a facility for rotationally driving the outer rotor as a reference, the main body 12 incorporating the stator and the resolver is set in the facility so that the angle of the resolver with respect to the stator can be adjusted with high accuracy. The fall of the angular positioning accuracy by the difference of a tation can be prevented, and the compatibility of the drive control circuit with respect to the 2-axis coaxial motor of this invention can be improved.

55 is a block diagram showing a drive circuit of the direct drive motors D1 and D2. When a motor rotation command is input from an external computer, the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DMC2 for the direct drive motor D2 are each a three-layer amplifier from the CPU. The drive signal is output to the AMP, and the drive current is supplied to the direct drive motors D1 and D2 from the three-layer amplifier AMP. As a result, the outer rotors 21 and 21 'of the direct drive motors D1 and D1 rotate independently to move the arms A1, A2 and FIG. 52. When the outer rotors 21 and 21 'rotate, the resolver signal is output from the resolver stators 35, 36, 35', and 36 'that have detected the rotation angle as described above, so that the resolver digital converter RDC The CPU input after digital conversion determines whether the outer rotors 21 and 21 'have reached the command position, and when the command position reaches the command position, the outer rotor is stopped by stopping the drive signal to the three-layer amplifier AMP. The rotation of (21, 21 ') is stopped. This enables servo control of the outer rotors 21 and 21 '.

In the case of driving a plurality of arms in a vacuum environment, the arm A1 may hit the wall of the vacuum chamber or the shutter of the vacuum chamber if the current rotation position of the arms A1 and A2 is not recognized when the power is turned on. In the present embodiment, a variable magnetoresistance comprising an absolute resolver stator 36 and 36 'for detecting an absolute position of one rotation of the rotary shaft, and an incremental resolver stator 35 and 35' for detecting a finer rotational position with a higher resolution. Since the type resolver is adopted, the rotational position control of the outer rotors 21 and 21 ', that is, the arms A1 and A2 can be performed with high accuracy.

In addition, although the resolver was used for rotation detection of the inner rotor 30 here, since a detector can be arrange | positioned to the atmospheric side inside the partition 13, in general, the servomotor used for high-precision positioning is performed with high precision. Optical encoders employed as position detection means for smoothly driving, magnetic encoders using magnetoresistive elements, and the like can also be used.

56 is a cross-sectional view showing a four-axis coaxial motor system according to a modification of the present embodiment.

In the modified example shown in FIG. 56, the direct drive motors D1 and D2 are directly arranged in two sets (four in total). However, the individual direct drive motors are the same as those shown in FIG. The same code | symbol is attached | subjected to a main component, and description is abbreviate | omitted.

In the present embodiment, the partition holder 113a is hermetically coupled to the upper disc portion 110 attached to the surface of the main body 12 connected in series via an O-ring OR, and a thin cylinder is formed on the outer circumferential surface thereof. The upper end of the 113b is made by TIG welding. The lower end of the thin cylinder 113b is TIG-welded to the holder 15 similarly to embodiment mentioned above. The partition wall is constituted by the partition holder 113a, the thin cylinder 113b, and the holder 15, but this is commonly used for four direct drive motors.

The upper surface of the disc part 110 is closed by the cover member 101, and the bearing holder 107 attached to the outer periphery supports the bearing 19. As shown in FIG. The disc part 110, the cover member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.

The mounting outer circumferential surface of the bearing holder 107 of the upper disc part 110 is located radially inward than the thin cylinder 113b, and therefore, when the bearing holder 107 is removed from the upper disc part 110, four The outer rotors 21 and 21 'can be detached upward without disassembling the upper disc portion 110. Therefore, it is not necessary to disassemble an airtight structure at the time of maintenance, etc., and operation can be made easy.

In this embodiment, since magnetic shield plates 25 'and 25' are arrange | positioned between 2nd outer rotor 21 'and 21' of the center, mutual magnetic interference is suppressed and a misdrive is performed. And inconvenience such as companion rotation is avoided. Moreover, between the main bodies 12 and 12, the magnetic shield plate 125 extended in the radial direction is arrange | positioned from the outer periphery to the inside of the thin cylinder 113b. The magnetic shield plate 125 is made of carbon steel, which is a magnetic material, and is interposed between the second stators 29 ', 29', and is adjacent to the second outer rotors 21 ', 21' affected by the missing magnetic flux. It acts as a magnetic shield that blocks each other's magnetic fields so that thrust in the wrong rotational direction is not generated. In this manner, a configuration in which the entire axial length is suppressed while being four axes coaxial with the effects of the other magnetic shields 25, 41 and 12b is possible.

In the above embodiment, a surface magnet type 32 pole 36 slot out rotor type brushless motor has been described using an example. However, the present invention is not limited to this type of motor and can be applied to a brushless motor. For example, it may be a permanent magnet embedded type, may be other slot combinations, or may be an inner rotor type.

In addition, as a countermeasure for each axis, the number of poles and the number of slots of the rotors adjacent to each other in the axial direction may be different. For example, in the case of two-axis coaxial, the first axis is 32 poles 36 slots, the second axis is 24 poles 27 slots, and in the case of 4-axis coaxials, the first and third axes are 32 poles 36 slots and the second axis. When the fourth axis has a configuration of 24 poles and 27 slots, mutual interference such as thrust generation in the rotational direction of the rotor and the magnetic coupling device due to the magnetic field of each axis can be prevented.

In addition, the permanent magnet of the rotor was described using an example in which nickel coating was used as a coating for enhancing corrosion resistance using a neodymium (Nd-Fe-B) magnet, but the material is not limited to this material and surface treatment. It is appropriately changed according to the environment and the like. For example, a samarium-cobalt (Sm · Co) -based magnet, which is difficult to be hot potato depending on the temperature conditions at the time of baking out, should be used. Titanium nitride coating with high barrier properties should be applied.

In addition, although the yoke was demonstrated using the example which made low carbon steel the material and performed nickel plating, it is not limited to this material and surface treatment, It changes suitably by the environment etc. used, Especially about surface treatment If it is used in a vacuum, it is necessary to carry out Carnizen plating, clean S plating, titanium nitride coating, etc., with less pinholes.

In addition, the method of fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is screwed from the outer diameter side of the yoke, but it is appropriately changed according to the environment used, and may be suitable for adhesion depending on the environment. Also good for.

In addition, although the bearings 19 and 19 'demonstrated the example using the four-point contact ball bearing of vacuum grease lubrication, it is not limited to this form, material, and lubrication method, but it depends on the environment used, load conditions, rotation speed, etc. The cross roller bearing may be changed as appropriate, and in the case of a four-axis coaxial motor, in order to further increase mechanical rigidity, the structure may be supported by a separate bearing, or a multi-point contact bearing may be used. If it is not available, the bearing supporting the rotor of each shaft and a separate bearing may be preloaded as deep groove ball bearings or angular bearings. It is also possible to use a metal lubrication without gas release, such as plating a soft metal.

In addition, although it demonstrated in the form which used a permanent magnet and a back yoke as an inner rotor which functions as a magnetic coupling, the material and shape of a permanent magnet and a back yoke are not limited to this. For example, depending on the mass of the resolver and the friction torque of the bearing, the number of poles may not be the same as that of the outer rotor or may not be the same width. It is also good for bumps that do not use permanent magnets.

Moreover, although it demonstrated as an example using a resolver as an angle detector, it changes suitably by manufacturing cost or resolution, For example, it may be an optical rotary encoder.

Moreover, although the example which used the four-point contact ball bearing of grease lubrication was demonstrated as the bearings 33 and 33 'rotatably supporting the rotation side of an angle detector, it is not limited to this type and a lubrication method, but it is installation space and friction If the multi-point contact bearing is not available, such as high speed rotation or reduction of friction torque, two angular bearings or deep groove ball bearings are arranged on each axis and preloaded. You may make it.

In addition, the materials, shapes, and manufacturing methods of the structural parts and the partitions arranged outside and inside the other partitions are appropriately changed depending on the production cost, the environment used, the load conditions, and the configuration.

The above-described motor system is mutually prevented from generating a thrust in the rotational direction by the magnetic flux leaking from the rotor, the stator, or the magnetic coupling used in the resolver, for each of the shafts. Magnetic shields are provided between the rotors of each axis to shield the magnetic fields, or magnetic shields are used to shield each other's electromagnetic fields so as not to interfere with each other's resolvers by the electromagnetic fields generated from the rotors, stators, and resolvers on each axis. By changing the number of poles of the rotor and the number of slots of the stator adjacent to each other in the direction, the magnetic interference generated between each axis is prevented, so the axial length of each axis and the axial distance of each axis are shortened. can do. Therefore, the structure which restrained the whole shaft length while being a multi-axis coaxial motor system called two-axis coaxial and four-axis coaxial is possible. In particular, in a system using a direct drive motor with a multi-axis configuration called 4-axis coaxial, two prog leg female robots can be installed, which can accurately position the chamber without greatly changing the chamber structure. Improve performance and uptime.

As mentioned above, although this invention was demonstrated with reference to embodiment, it cannot be overemphasized that this invention is limited to the said embodiment, Of course, it can change and improve suitably. For example, the direct drive motor of the present embodiment can be used not only in a vacuum atmosphere but also in an atmosphere outside the atmosphere. For example, in the case of a semiconductor manufacturing process, although the reactive gas for etching is introduce | transduced into a vacuum chamber after vacuum exhaust, since the inside and the exterior are shielded by the partition in the direct drive motor of this embodiment, a motor coil There is no fear of etching or an insulating material.

The present invention relates to a motor system using a plurality of direct drive motors used in an atmosphere outside the atmosphere, for example, in a vacuum.

Claims (6)

In a motor system that coaxially combines a first direct drive motor and a second direct drive motor to be used in an atmosphere outside the atmosphere, Each direct drive motor, Housings, A partition wall extending from the housing and separating the atmosphere side and the outside of the atmosphere; An outer rotor disposed outside the atmosphere with respect to the partition wall; A stator disposed on the atmosphere side with respect to the partition wall, and an inner rotor disposed on the atmosphere side with respect to the partition wall and co-rotating with the outer rotor; It has a detector for detecting the rotation position of the inner rotor, The inner rotor of the first and second direct drive motors is disposed outside the axial direction with the stators of the first and second direct drive motors interposed therebetween. The method of claim 1, The detector of the said 1st and said 2nd direct drive motor is adjustable from both sides of an axial direction in the state which connected said 1st and said 2nd direct drive motors, The motor system characterized by the above-mentioned. The method according to claim 1 or 2, At one end in the axial direction of the housing, a concave portion is formed to fit into the convex portion formed at the other end in the axial direction of the other housing, and the first and second direct drive motors are fitted by A motor system characterized by connecting a plurality of pairs. The method of claim 3, wherein A motor system provided with a member extending between shafts between said housing and said other housing. The method according to claim 1 or 2, A plurality of pairs of the first and second direct drive motors are connected by fastening end portions of the partition walls in the axial direction. The method according to any one of claims 1 to 5, A wiring in the stator of the first and second direct drive motors extends between the first and second direct drive motors.

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