WO2008050418A1 - Dispositif de support de rotation - Google Patents

Dispositif de support de rotation Download PDF

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Publication number
WO2008050418A1
WO2008050418A1 PCT/JP2006/321276 JP2006321276W WO2008050418A1 WO 2008050418 A1 WO2008050418 A1 WO 2008050418A1 JP 2006321276 W JP2006321276 W JP 2006321276W WO 2008050418 A1 WO2008050418 A1 WO 2008050418A1
Authority
WO
WIPO (PCT)
Prior art keywords
rotor
bearing
direct drive
resolver
stator
Prior art date
Application number
PCT/JP2006/321276
Other languages
English (en)
Japanese (ja)
Inventor
Shigeru Endou
Shin Kumagai
Yusuke Ota
Kazuo Nagatake
Licheng Dong
Atsushi Horikoshi
Toshimasa Wada
Original Assignee
Nsk Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nsk Ltd. filed Critical Nsk Ltd.
Priority to PCT/JP2006/321276 priority Critical patent/WO2008050418A1/fr
Publication of WO2008050418A1 publication Critical patent/WO2008050418A1/fr

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K16/00—Machines with more than one rotor or stator
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
    • H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
    • H02K21/22—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating around the armatures, e.g. flywheel magnetos
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/08—Structural association with bearings
    • H02K7/086—Structural association with bearings radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
    • H02K7/088—Structural association with bearings radially supporting the rotor around a fixed spindle; radially supporting the rotor directly radially supporting the rotor directly
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/08—Structural association with bearings
    • H02K7/09—Structural association with bearings with magnetic bearings

Definitions

  • the present invention relates to a rotation support device suitable for use in a direct drive motor used in an atmosphere outside the atmosphere, for example, in a vacuum.
  • a workpiece is processed in an ultra-high vacuum atmosphere in a vacuum chamber in order to eliminate impurities as much as possible.
  • a lubricant containing a volatile component such as general grease for a drive shaft bearing. Because it is impossible, the lubricity is improved by plating soft metals such as gold and silver on the inner and outer rings of the bearing.
  • a stable material with excellent heat resistance and low emission gas is selected for the coil insulating material of the drive motor, the wiring coating material, and the adhesive of the laminated magnetic pole.
  • a direct drive motor in which a stator is arranged inside a vacuum sealing body and an output member is arranged outside thereof, and a frog redder arm is driven using an output member, that is, a rotor.
  • a direct drive motor in which a stator is arranged inside a vacuum sealing body and an output member is arranged outside thereof, and a frog redder arm is driven using an output member, that is, a rotor.
  • the coil insulating material, wiring coating, and the like attached to the stator are disposed inside the vacuum sealed body maintained at atmospheric pressure, so that they are disposed in the vacuum chamber. In this case, it is possible to avoid the problem of the storage of impure molecules and the generation of heat.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2000-69741
  • Patent Document 2 Japanese Patent Application Laid-Open No. 5-288570
  • the vacuum actuator in Patent Document 1 includes a rolling bearing that supports a ring-shaped boss that is connected to an arm and rotates in a vacuum atmosphere.
  • a rolling bearing that supports a ring-shaped boss that is connected to an arm and rotates in a vacuum atmosphere.
  • the former method has the problem that it is difficult to reduce the size of the device because the shaft length becomes longer by using two bearings, and the latter method causes a temperature difference between the inner ring and the outer ring due to temperature changes.
  • Patent Document 2 a spring member for applying a preload by urging an outer ring of a deep groove ball bearing supporting a rotor in an axial direction with respect to a stator By providing this, even when one deep groove ball bearing is used, there is no play and high-precision rotation is possible.
  • the technique disclosed in Patent Document 2 increases the number of parts by installing a spring member, which increases the shaft length and reduces the spring. Therefore, there is a problem that proper preload may not be applied.
  • a fixed ring of a rolling bearing that supports a rotating body is used as a clearance fit, and the fixed ring 20 is biased by a preload spring to apply preload.
  • the fixed ring is supported only by the preload spring, the rotational center of the rotating body is displaced and abnormal vibration occurs, resulting in poor rotational accuracy.
  • the present invention has been made in view of the problems of the prior art, and it is an object of the present invention to provide a rotation support device that can eliminate play of a rolling bearing without using a spring member.
  • the rotational support device of the invention 1 includes a housing,
  • a first rotating body that rotates relative to the housing
  • a first bearing that supports the first rotating body with respect to the housing
  • a second rotating body that rotates relative to the housing
  • the rotation support device of the invention 2 is the rotation support device of the invention 1, wherein the rotation support device is A stator disposed opposite to the first rotator, and a detector for detecting a rotational position of the second rotator, and the stator includes the first rotator and the second rotator. It is used for a direct drive motor that drives the at the same time.
  • the rotation support device includes a stator disposed to face the first rotating body, and a detector that detects a rotation position of the second rotating body, and the stator includes the aforementioned When used in a direct drive motor that drives the first rotating body and the second rotating body at the same time, high-precision rotation of the direct drive motor can be supported.
  • the rotation support device of the invention 3 is the rotation support device of the invention 2, wherein the direct drive motor is used in an atmosphere outside the atmosphere, extends the housing force, and separates the partition wall separating the atmosphere side and the atmosphere outside.
  • the first rotating body is arranged outside the atmosphere, and the stator and the second rotating body are provided on the atmosphere side.
  • the direct drive motor is used in an atmosphere outside the atmosphere, and the first rotating body is disposed outside the atmosphere with respect to the partition wall that extends the housing force and separates the atmosphere side and the atmosphere outside.
  • the stator and the second rotating body are provided on the atmosphere side, and by placing the detector on the atmosphere side with respect to the partition wall, the occluded impurity molecules of the wiring coating are in an atmosphere outside the atmosphere from the partition wall.
  • the stator detects the rotation angle of the second rotating body by the detector by simultaneously driving the first rotating body and the second rotating body, The rotation angle of the first rotating body can be obtained with high accuracy.
  • the direct drive motor of invention 4 is a direct drive motor used in an atmosphere outside the atmosphere.
  • a partition wall extending the housing force and isolating the atmosphere side and the atmosphere outside;
  • a stator and an inner rotor disposed on the atmosphere side with respect to the partition;
  • a detector for detecting the rotational speed of the inner rotor The stator is characterized in that the outer rotor and the inner rotor are driven simultaneously.
  • the housing in the direct drive motor used in an atmosphere outside the atmosphere, the housing, the partition that extends the housing force and separates the atmosphere side from the outside of the atmosphere, and the outside of the atmosphere with respect to the partition
  • An outer rotor disposed; a stator and an inner rotor disposed on the atmosphere side with respect to the partition; and a detector that detects a rotational speed of the inner rotor, wherein the stator includes the outer rotor and the inner rotor.
  • the rotor Since the rotor is driven at the same time, by placing the detector on the atmosphere side from the partition wall, the occlusion impurity molecules of the wiring coating are prevented from contaminating the atmosphere outside the atmosphere from the partition wall, and the stator is By detecting the rotation angle of the inner rotor by the detector by simultaneously driving the outer rotor and the inner rotor, The rotation angle can be obtained with high accuracy.
  • the direct drive motor of invention 5 is the direct drive motor of invention 4, characterized in that the outer rotor and the inner rotor have the same number of magnetic poles.
  • the rotation angles of the outer rotor and the inner rotor become equal, so the rotation angle of the inner rotor is detected.
  • the rotation angle of the outer rotor can be obtained immediately.
  • the present invention is not limited to this.
  • the number of magnetic poles in the outer rotor and the number of magnetic poles in the inner rotor may be a multiple or a fraction of an integer.
  • a direct drive motor according to a sixth aspect of the present invention is the direct drive motor according to the fourth or fifth aspect, wherein an inner rotor is disposed radially inward of the stator.
  • the stator when the inner rotor is arranged on the inner side in the radial direction of the stator, the stator can be driven reliably, but it may be arranged so as to be shifted in the axial direction.
  • the direct drive motor of invention 7 is a direct drive motor used in an atmosphere outside the atmosphere. Knowing and
  • a partition wall extending the housing force and isolating the atmosphere side and the atmosphere outside;
  • An outer rotor disposed outside the atmosphere with respect to the partition wall, and a magnetic coupling rotor that rotates integrally with the outer rotor;
  • a stator that is disposed on the atmosphere side with respect to the partition wall and drives the outer rotor; an inner rotor that is disposed on the atmosphere side with respect to the partition wall;
  • the magnetic coupling rotor and the inner rotor rotate in synchronization by a magnetic coupling action.
  • the housing, the partition extending the housing force, separating the atmosphere side and the outside of the atmosphere, and disposed outside the atmosphere with respect to the partition
  • An outer rotor and a rotor for magnetic coupling that rotates integrally with the outer rotor, a stator that is disposed on the atmosphere side with respect to the partition, and that is disposed on the atmosphere side with respect to the partition.
  • An inner rotor and a detector for detecting the rotational speed of the inner rotor, and the magnetic coupling rotor and the inner rotor rotate synchronously by a magnetic coupling action.
  • a force in which the “outer rotor” and the “magnetic coupling rotor” are different members in form for example, when a driving magnet and a magnetic coupling magnet are provided on a single rotor, It can be said that the partial force of the rotor provided with the driving magnet ⁇ outer rotor "and the portion of the rotor provided with the magnet for magnetic force coupling is the" magnetic coupling rotor ". included.
  • the direct drive motor of invention 8 is the direct drive motor of invention 7, wherein the peak value of the resonance frequency gain in the magnetic coupling system is suppressed by the partition wall. It is characterized by that.
  • the partition between the atmosphere-side rotor and the atmosphere-side rotor can be positioned with less vibration due to the effect of suppressing the peak value of the resonance frequency gain in the magnetic coupling system.
  • the direct drive motor of the invention 9 is a direct drive motor used in an atmosphere outside the atmosphere.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • the partition has an attachment portion attached to the housing, the outer rotor, a cylindrical portion extending between the stator and the inner rotor, and a bottom portion, and the bottom portion is attached to the housing. On the other hand, it is restricted in the axial direction.
  • the housing in the direct drive motor used in an atmosphere outside the atmosphere, the housing, the partition that extends the housing force and separates the atmosphere side from the outside of the atmosphere, and the outside of the atmosphere with respect to the partition wall.
  • An outer rotor disposed; a stator and an inner rotor disposed on the atmosphere side with respect to the partition; and a detector that detects a rotational position of the inner rotor, wherein the stator drives the outer rotor. Since the inner rotor is rotated together with the outer rotor, by placing the detector inside the partition wall, it is possible to prevent the impurity molecules stored in the wiring cover from contaminating the atmosphere outside the partition wall.
  • the partition wall includes an attachment portion attached to the housing, the outer rotor, a cylindrical portion extending between the stator and the inner rotor, and a bottom portion, and the bottom portion is Since the housing is not restrained in the axial direction, the bottom portion is pressed against the housing even when a dimensional error or deformation occurs in the partition wall due to dimensional accuracy, mechanical accuracy, or temperature change.
  • the axial direction of the bulkhead because it is not pulled or pulled Stress and bending stress can be relieved, which can prevent seal failure and breakage. Further, since it is not necessary to process the mounting portion of the partition wall and the housing to which the partition wall is mounted with high accuracy, a lower cost direct drive motor can be provided.
  • the direct drive motor of the invention 10 is a direct drive motor used in an atmosphere outside the atmosphere.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • the partition wall connects the mounting portion attached to the housing, the outer rotor, a cylindrical portion extending between the stator and the inner rotor, and the mounting portion and the cylindrical portion. And a thickness of the connecting portion is thinner than a thickness of the mounting portion.
  • the partition wall is attached to the housing, the outer rotor, the cylindrical portion extending between the stator and the inner rotor, and the A connecting portion that connects the mounting portion and the tubular portion, and the thickness of the mounting portion is thicker than the thickness of the connecting portion, resulting in dimensional accuracy, mechanical accuracy, and temperature changes.
  • the thin-walled connecting portion is deformed first, so that the axial stress and bending stress of the partition wall can be relieved, thereby preventing a seal failure or breakage. Can be prevented. Therefore, since it is not necessary to process the mounting portion of the partition wall and the housing to which the partition wall is mounted with high accuracy, a lower cost direct drive motor can be provided.
  • the direct drive motor of invention 11 is similar to the direct drive motor of invention 10,
  • the connecting portion is wavy.
  • the motor system of the invention 12 is a motor system in which a plurality of direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • the outer rotor force of at least one direct drive motor is supported by a bearing with respect to the outer rotor of another direct drive motor.
  • each direct drive motor force, udging, and the housing force extend, and the atmosphere side and the atmosphere
  • the stator drives the outer rotor and the inner rotor is rotated together with the outer rotor. Therefore, by placing the detector inside the partition wall, the wiring cover has an impure impurity. Molecules are prevented from contaminating the atmosphere outside the partition.
  • the outer rotor force of at least one direct drive motor is supported by a bearing with respect to the outer rotor of another direct drive motor, so that the outer rotors of a plurality of direct drive motors are coaxial with each other.
  • the operation accuracy can be increased.
  • the bearing supporting the powerful outer rotor can be exposed. Can be easily removed and removed, improving maintainability.
  • the motor system according to a thirteenth aspect of the present invention is the motor system according to the twelfth aspect of the present invention, wherein the partition wall force of one direct drive motor is common to the partition walls of another direct drive motor.
  • the partition wall force of one direct drive motor is the same as that of the partition wall of another direct drive motor, because the number of parts and seal locations can be reduced.
  • a motor system of an invention 14 is the motor system of the invention 13, characterized in that the partition wall has a cup shape.
  • the partition wall is cup-shaped because the number of parts is reduced and the number of sealed portions is also reduced.
  • the partition wall is not limited to a cup shape, and it may be combined with a cylinder and a disk and welded together, or a combination of a truncated cone and a disk whose diameter is reduced in the direction of removing the outer rotor. Also good.
  • a motor system according to a fifteenth aspect of the present invention is a motor system in which a plurality of direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • each direct drive motor force, udging, and the housing force extend, and the atmosphere side and the atmosphere
  • the stator drives the outer rotor and the inner rotor is rotated together with the outer rotor. Therefore, by placing the detector inside the partition wall, the wiring cover has an impure impurity. Molecules are prevented from contaminating the atmosphere outside the partition. Also, since the outer rotor of the direct drive motor is supported by bearings at both ends of the housing, the mechanical accuracy of each other is hardly affected. Therefore, it is possible to provide a motor system with a large load capacity and allowable moment V.
  • the motor system according to a sixteenth aspect of the present invention is the motor system according to the fifteenth aspect of the present invention, wherein the shape of one end of the V is shifted so that the outer rotor of all direct drive motors can be removed in the axial direction. It is characterized by that.
  • the rotor can also remove the bulkhead force, which can be easily inspected and removed, improving maintainability. Furthermore, since it is only necessary to remove the outer rotor outside the partition wall, it is not necessary to remove the entire direct drive motor, so that a leak check or the like is not required at the time of reassembly, and assemblability is improved.
  • the motor system according to a seventeenth aspect of the present invention is the motor system according to the fifteenth aspect of the present invention, wherein the bulkhead force of one direct live motor is common to the bulkheads of other direct drive motors. And features.
  • the partition wall force of one direct live motor is the same as that of the partition wall of another direct drive motor, because the number of parts and the seal location can be reduced.
  • the motor system according to an eighteenth aspect of the invention is the motor system according to the fifteenth aspect of the invention, wherein the partition wall has sealing mechanisms for the housing at both ends.
  • the partition wall has a sealing mechanism (O-ring or the like) with the housing at both end portions, the both end portions of the housing can be disposed outside the atmosphere, so that the direct drive motor
  • the outer rotor can be supported by bearings on both ends of the housing.
  • the motor system of the nineteenth aspect of the present invention is a motor system in which four or more direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • the outer rotor force of one direct drive motor is supported by a bearing against one of the ends of the housing, and the outer rotor of the other direct drive motor is connected to the other end of the housing.
  • the outer rotor force 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.
  • each direct drive motor force A partition extending from the housing and isolating the atmosphere side from the atmosphere outside, an outer rotor disposed outside the atmosphere with respect to the partition, a stator disposed on the atmosphere side with respect to the partition, and an inner side A rotor and a detector that detects a rotational position of the inner rotor, and the stator drives the outer rotor, and the inner rotor is rotated together with the outer rotor.
  • the impurities stored in the wiring cover from contaminating the atmosphere outside the partition wall.
  • the outer rotor of the direct drive motor is supported by bearings on both ends of the housing, and the outer rotor of each direct drive motor is connected to the outer side of another direct drive motor. Since the rotor is supported by the bearing, the same outer rotor connected by the bearing has a high degree of coaxiality with each other, and is installed at the end of the other housing.
  • a motor system can be provided with a small mutual interference of mechanical accuracy. Therefore, when applied to a 2-axis coaxial frog redder arm robot, it is possible to improve the operation accuracy and increase the load.
  • the motor system according to a twentieth aspect of the present invention is the motor system according to the nineteenth aspect of the present invention, wherein the shape of one end of the housing V is shifted so that the outer rotors of all the direct drive motors can be removed in the axial direction. It is characterized by being beaten!
  • one end shape of the housing supporting the partition wall structure is made detachable in the axial direction of the outer rotor of the direct drive motor, so that the outer side of all the direct drive motors
  • the rotor can also remove the bulkhead force, which can be easily inspected and removed, improving maintenance.
  • it is only necessary to remove the outer rotor on the outside of the partition wall so there is no need to remove the entire direct drive motor, so there is no need to check for leaks, etc., improving assembly.
  • a motor system according to a twenty-first aspect of the invention is the motor system according to the nineteenth aspect, wherein the housing can be divided into units commonly used in two adjacent direct drive motors. [0029] With this, if the housing can be divided into units commonly used in two adjacent direct drive motors, it is excellent in assemblability, and adjustments such as phase alignment between the motor and the detector are possible. Easy to do, so preferred.
  • the motor system of the invention 22 is the motor system of the invention 19 characterized in that the partition wall force of one direct live motor is common to the partition walls of other direct drive motors.
  • the partition force of one direct drive motor is the same as that of the partition wall of another direct drive motor, because the number of parts and the seal location can be reduced.
  • a motor system according to a twenty-third aspect of the present invention is the motor system according to the nineteenth aspect of the present invention, characterized in that both ends of the partition wall have a sealing mechanism with the housing.
  • the partition wall has a sealing mechanism (O-ring or the like) with the housing at both ends, the both ends of the housing can be disposed outside the atmosphere, so the direct drive motor
  • the outer rotor can be supported by bearings at both ends of the housing.
  • the motor system of the invention 24 is a motor system in which a first direct drive motor and a second direct drive motor used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • the outer rotor of the second 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 removably attached to the housing.
  • each direct drive motor includes a housing and the housing cover.
  • a partition wall that separates the atmosphere side from the atmosphere outside, 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 the atmosphere with respect to the partition wall
  • an inner rotor that rotates with the outer rotor, and a detector that detects the rotational position of the inner rotor.By placing the detector on the atmosphere side of the partition wall, It is possible to prevent the impure molecules of the wiring coating from contaminating the atmosphere outside the atmosphere of the partition wall.
  • 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, and the first rotor is supported by the first rotor. Since the outer rotor of the direct drive motor is supported via a first bearing by a bearing holder that is detachably attached to the housing, the first rotor can be removed by removing the bearing holder. The direct drive motor can be separated from the housing force, and maintenance work including inspection of the bearing attached to the bearing holder can be saved.
  • a motor system according to a twenty-fifth aspect of the present invention is the motor system according to the twenty-fourth aspect, wherein the bearing holder is fixed to the housing by a bolt, and the bolt is disposed outside the outer rotor of the first direct drive motor. It is characterized by.
  • the bearing holder is fixed to the housing by the bolt, and when the bolt is arranged outside the outer rotor of the first direct drive motor, the outer rotor to be applied is This is preferable because the bolt can be loosened without being removed.
  • “disposed outside the outer rotor” means at least the bolt removal In this case, it means that the bolt or tool and the outer rotor do not interfere with each other. Therefore, when the outer diameter of the outer rotor is non-circular, depending on the rotational phase of the outer rotor, even if the bolt is inside the outer periphery, the bolt is rotated by rotating the outer rotor. When going outside, the bolt shall be located outside the outer rotor.
  • the motor system of invention 26 is the motor system of inventions 24 to 25, 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 the maximum outer diameter of the partition wall. It ’s getting bigger,
  • 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 becoming.
  • 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
  • a motor system according to a twenty-seventh aspect is the motor system according to the twenty-sixth aspect, wherein a bolt for fixing the first bearing and the bearing holder is exposed when the housing force of the bearing holder is removed.
  • the forceful bolt can be loosened, and thus the first This is preferable because the outer rotor of the direct drive motor can be easily disassembled.
  • “exposed” means that a space is created in which a tool can be engaged and a bolt can be loosened.
  • a motor system according to a twenty-eighth aspect of the present invention is the motor system according to the twenty-fourth aspect of the present invention, wherein the outer rotor of the second direct drive motor is formed by connecting a plurality of parts with bolts, and the outer rotor is in a state where the motor system is assembled. By loosening the bolts that connect the multiple parts, it is possible to remove some of the parts. With the part removed, the second bearing and the first direct drive motor The bolt that fixes the outer ring rotor is exposed.
  • the outer rotor of the second direct drive motor is formed by connecting a plurality of parts (for example, a second outer rotor 21b ′ and a cylindrical member 23 ′ described later) with a bolt, and the motor system is In the assembled state, by loosening the bolt that connects the plurality of parts of the outer rotor, it is possible to remove some of the parts (for example, the cylindrical member 23 '), and remove the part of the parts.
  • the bolt for fixing the second bearing and the outer ring rotor of the first direct drive motor is exposed, the powerful bolt can be loosened. Therefore, the outer rotor of the second direct drive motor can be This is preferable because it can be easily disassembled!
  • a motor system according to a twenty-ninth aspect of the present invention is the motor system according to the twenty-eighth aspect, wherein the bolt of the second direct drive motor is loosened by loosening a bolt that fixes the second bearing and the outer ring rotor of the first direct drive motor. The remaining parts of the outer rotor can be pulled out in the axial direction along the partition wall.
  • a motor system according to a thirty-fifth aspect of the present invention is the motor system according to any one of the twenty-fourth to thirty-ninth aspects, wherein the partition wall and the housing are common to each direct drive motor. Accordingly, in each direct drive motor, it is preferable that the partition wall and the housing are in common because the number of parts can be reduced and the number of seal members for sealing between the members is also reduced.
  • a motor system according to a thirty-first aspect of the present invention is a motor system in which a plurality of direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • a magnetic shield is disposed between at least one of the stators.
  • the housing in the direct drive motor used in an atmosphere outside the atmosphere, the housing, the partition extending the housing force and separating the atmosphere side from the outside of the atmosphere, and the outside of the atmosphere with respect to the partition wall.
  • An outer rotor arranged; a stator and an inner rotor arranged on the atmosphere side with respect to the partition; and a detector that detects a rotational position of the inner rotor, and the stator drives the outer rotor. Since the inner rotor is rotated together with the outer rotor, by placing the detector inside the partition wall, it is possible to prevent the impurities stored in the wiring cover from contaminating the atmosphere outside the partition wall.
  • the magnetic shield is arranged between at least one of the outer rotors, the inner rotors, and the stators in adjacent direct drive motors, the rotor is affected by the leakage magnetic flux generated by the stator force and electromagnetic noise.
  • the direct motor adjacent to the rotor can be prevented from reaching the stator. Therefore, the motor system can be made thin.
  • the motor system of the invention 32 is a motor system in which a plurality of direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled.
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • At least one of the stators has a different number of magnetic poles.
  • the housing In a direct drive motor used in an atmosphere outside the atmosphere, the housing, the housing force extends, the partition that separates the atmosphere side and the outside of the atmosphere, and the outside of the partition wall are arranged outside the atmosphere.
  • the motor system can be made thin.
  • the motor system of the invention 33 is a motor system in which a plurality of direct drive motors used in an atmosphere outside the atmosphere are coaxially coupled. Each direct drive motor
  • a partition wall extending the housing force and isolating the atmosphere side from the atmosphere outside;
  • a stator disposed on the atmosphere side with respect to the partition; an inner rotor disposed on the atmosphere side with respect to the partition;
  • a rotating wheel of a bearing device that rotatably supports the outer rotor is fitted into a rotor yoke.
  • the housing in the direct drive motor used in an atmosphere outside the atmosphere, the housing, the partition extending the housing force and separating the atmosphere side from the outside of the atmosphere, and the outside of the atmosphere with respect to the partition wall.
  • An outer rotor disposed; a stator and an inner rotor disposed on the atmosphere side with respect to the partition; and a detector that detects a rotational position of the inner rotor, wherein the stator drives the outer rotor. Since the inner rotor is rotated together with the outer rotor, by placing the detector inside the partition wall, it is possible to prevent the impurity molecules stored in the wiring cover from contaminating the atmosphere outside the partition wall.
  • Rotational accuracy is achieved by fitting the rotating wheel of the bearing device that is rotatably supported with the outer rotor to a rotor yoke that is easy to obtain processing accuracy and has a linear expansion coefficient substantially the same as the driving wheel of the bearing device. And improvement of friction torque due to temperature change can be prevented.
  • FIG. 1 is a perspective view of a frog redder arm type transport device using a direct drive motor that is effective in the present embodiment.
  • FIG. 2 is a view of the configuration of FIG. 1 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 3 is an enlarged view showing an arrow III part in FIG.
  • FIG. 4 is a diagram illustrating an example of a resolver control circuit.
  • FIG. 5 is a diagram showing an example of a motor control circuit.
  • FIG. 6 is a cross-sectional view showing a modification of the present embodiment.
  • FIG. 7 Frog redder arm type using a direct drive motor that works well with this embodiment It is a perspective view of a conveying apparatus.
  • Fig. 8 is a view of the configuration of Fig. 7 taken along line ⁇ - ⁇ and viewed in the direction of the arrow.
  • FIG. 9 is a view of the configuration of FIG. 8 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 10 is a diagram illustrating an example of a resolver control circuit.
  • FIG. 11 is a diagram showing an example of a motor control circuit.
  • FIG. 12 is a diagram showing a modification of the present embodiment.
  • FIG. 9 is a cross-sectional view similar to FIG. 8 of a direct drive motor that can be used in the transport device shown in FIG.
  • FIG. 14 A schematic diagram showing a state in which eddy current loss occurs in the partition wall 113.
  • FIG. 15 is a schematic view similar to FIG. 14 showing three magnets arranged in a line.
  • FIG. 16 is a block diagram of a motor control system when there is no partition wall.
  • FIG. 17 is a block diagram of a motor control system when there is a partition wall.
  • FIG. 18 is a diagram showing frequency characteristics of a transfer function G.
  • FIG. 19 is a diagram showing frequency characteristics of a transfer function G.
  • FIG. 20 is a view showing the spring stiffness of the magnetic coupling.
  • FIG. 21 is a perspective view of a frog redder arm type transport device using a direct drive motor that works according to the present embodiment.
  • FIG. 22 is a view of the configuration of FIG. 21 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 23 is a diagram illustrating an example of a resolver control circuit.
  • FIG. 24 is a diagram showing an example of a motor control circuit.
  • ⁇ 25 It is a cross-sectional view showing a second embodiment.
  • FIG. 26 is a sectional view showing a third embodiment.
  • FIG. 28 is a perspective view of a frog redder arm type conveyance device using a motor system including a direct drive motor that is effective in the present embodiment.
  • FIG. 29 is a view of the configuration of FIG. 28 taken along the line ⁇ - ⁇ and viewed in the direction of the arrow.
  • FIG. 30 is a diagram illustrating an example of a resolver control circuit.
  • FIG. 31 is a diagram showing an example of a motor control circuit.
  • FIG. 32 is a cross-sectional view showing a second embodiment.
  • FIG. 33 is a perspective view of a frog redder arm type transfer device using a direct drive motor that works according to the present embodiment.
  • FIG. 34 is a view of the configuration of FIG. 33 taken along the line ⁇ - ⁇ and viewed in the direction of the arrow.
  • FIG. 35 is a diagram showing an example of a resolver control circuit.
  • FIG. 36 is a diagram showing an example of a motor control circuit.
  • FIG. 37 is a perspective view of a frog redder arm type conveyance device using a direct drive motor that works according to the present embodiment.
  • FIG. 38 is a view of the configuration of FIG. 37 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 39 is a diagram illustrating an example of a resolver control circuit.
  • FIG. 40 is a diagram showing an example of a motor control circuit.
  • FIG. 41 is a cross-sectional view showing a disassembling process of the motor system according to the present embodiment.
  • FIG. 42 is a cross-sectional view showing an exploded process of the motor system according to the present embodiment.
  • FIG. 43 is a cross-sectional view showing an exploded process of the motor system according to the present embodiment.
  • FIG. 44 is a cross-sectional view showing an exploded process of the motor system according to the present embodiment.
  • FIG. 45 is a perspective view showing an exploded process of the motor system according to the present embodiment.
  • FIG. 46 is a perspective view showing a disassembly process of the motor system according to the present embodiment.
  • FIG. 47 is a perspective view showing an exploded process of the motor system according to the present embodiment.
  • FIG. 48 is a perspective view showing a disassembly process of the motor system according to the present embodiment. 49] A sectional view showing a modification of the present embodiment.
  • FIG. 50 is a perspective view of a frog redder arm type transfer device using a direct drive motor that is powerful in a modified example.
  • FIG. 51 is a perspective view of a frog redder arm type conveyance device using a direct drive motor that works according to the present embodiment.
  • FIG. 52 is a view of the configuration of FIG. 51 taken along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 53 is a diagram showing an example of a resolver control circuit.
  • FIG. 54 is a diagram showing an example of a motor control circuit.
  • FIG. 55 is a cross-sectional view showing a modification of the present embodiment. Explanation of symbols
  • FIG. 1 is a perspective view of a frog redder arm type transfer device using a direct drive motor that works in this embodiment.
  • two direct drive motors Dl 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.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed.
  • a device having a plurality of arms such as a scalar type or a frog redder type shown in the figure requires a plurality of rotary motors.
  • the surface area of contact with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc., should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space.
  • a surface magnet type 32-pole 36-slot outer rotor brushless type direct drive motor is used.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good.
  • FIG. 2 is a view of the configuration of FIG. 1 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow. With reference to Fig. 2, the internal structure of a two-axis motor system with a direct drive motor connected directly will be described in detail. First, a direct drive motor D1 using a rotation support device that is powerful in the present embodiment will be described.
  • a hollow cylindrical main body 12 fitted into the central opening 10a of the disk 10 installed on the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition wall 13 attached to the upper end thereof.
  • the center of the main body 12 can be used to pass wiring to the stator.
  • the main body 12 and the disc 10 constitute a housing.
  • the partition wall 13 is made of stainless steel, which is a non-magnetic material, and extends from the peripheral edge of the thick bottom portion 13a fitted to the main body 12 to the direct drive motors Dl and D2 in the axial direction. It consists of an existing thin cylindrical portion 13 b and a holder 15. Therefore, the partition wall 13 is commonly used for the direct drive motors Dl and D2.
  • the lower end of the cylindrical portion 13b is joined to a holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 with bolts 16.
  • the contact surface between the holder 15 and the disc 10 is provided with a groove force that fits the seal member. After the seal member OR is fitted into the groove, the holder 15 and the disc 10 are fastened by the bolt 16. As a result, the fastening part is isolated from the atmospheric force.
  • the partition wall 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance, and is particularly magnetic.
  • the holder 15 is also made of SUS316 because of its weldability with the partition wall 13.
  • the partition wall 13 and the holder 15 are airtightly joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are hermetically sealed by O-rings OR, respectively. Therefore, the internal space surrounded by the disk 10 and the partition wall 13 is also hermetically sealed.
  • the partition wall 13 is not necessarily made of a nonmagnetic material. Further, instead of using an O-ring OR, the members may be hermetically sealed by electron beam welding or laser beam welding.
  • a bearing holder 17 is fixed by bolts 18 on the outer peripheral upper surface of the disk 10.
  • the bearing holder 17 is fitted with an outer ring of a four-point contact ball bearing 19 that is used in a vacuum, and is fixed by bolts 20.
  • the inner ring of the bearing 19 is fitted to the outer periphery of the first outer rotor 21 and is fixed by bolts 22. That is, the first outer rotor 21 is A cylindrical member 23 that is rotatably supported with respect to the partition wall 13 and supports the arm Al (FIG. 1) is fixed by a bolt 24.
  • the bolt 24 fastens the magnetic shield plate 25 extending inward in the radial direction together with 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 fixing device with the surface plate G that is a chamber, and a lower surface thereof.
  • a groove 10b is provided to fill the O-ring OR.
  • the magnetic shield plate 25 is subjected to nickel plating in order to enhance the anti-corrosion and corrosion resistance after press-forming the SPCC steel plate, which is a magnetic material.
  • the bearing 19, which is the first bearing is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing of the direct drive motor D 1 is required, so that the two-axis coaxial motor system of the present invention can be made thinner.
  • Bearing 19 is made of martensitic stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even in a vacuum.
  • the bearing 19 may be made of a metal lubricated material in which a soft metal such as gold or silver is plated on the inner ring and the outer ring so as not to release outgas even in a vacuum, or a four-point contact ball. Because it is a bearing, it can receive a moment in the direction in which the first outer rotor 21 tilts from the arm A1, but it is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. Yes, it can be used under preload conditions, or fluorine film treatment (DFO) can be performed to improve lubricity! ⁇ .
  • DFO fluorine film treatment
  • the first outer rotor 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material for forming a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It consists of a wedge (not shown).
  • Permanent magnet 21a has a configuration of 32 poles, each of which has 16 poles of N poles and S poles alternately made of magnetic metal, and is divided into segments. Each of the permanent magnets 21a has a sector shape.
  • the permanent magnet 21a is a neodymium (Nd—Fe—B) based magnet having a high energy product, and has a nickel coating to enhance corrosion resistance.
  • the yoke 21b is made of a low-carbon steel having high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the first outer rotor 21 has a surface for fitting and fixing the inner ring of the bearing 19 and the cylindrical member 23.
  • the four-point contact ball bearing 19 is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the parts to be assembled. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 that is a rotating ring is tightly fitted to the yoke 21b that is easy to achieve machining accuracy and the linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring of the bearing 19, which is a fixed ring, is fitted into the austenitic stainless steel bearing holder or aluminum boss so that the rotational accuracy of the bearing 19 decreases and the friction torque increases due to temperature rise. Is configured to prevent.
  • a first stator 29 is arranged on the inner side in the radial direction of the partition wall 13 so as to face the inner peripheral surface of the first outer rotor 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12.
  • the first stator 29 is formed of a laminated material of electromagnetic steel plates and is insulated from each salient pole. As a process, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a first inner rotor 30 is disposed on the radially inner side of the first stator 29.
  • the first inner rotor 30 is rotatably supported by a deep groove ball bearing 33 that is a second bearing with respect to a resolver holder 32 that is bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock yoke 30b.
  • the permanent magnet 30a has a configuration of 32 poles, and each of 16 magnets of N poles and S poles is made of a magnetic metal alternately. Accordingly, the first inner rotor 30 is rotated along with the first outer rotor 21 driven by the first stator 29.
  • FIG. 3 is a partially simplified view showing an enlarged view of an arrow III part in FIG. Figure
  • the bearing 33 that rotatably supports the first inner rotor 30 is a deep groove ball bearing.
  • a deep groove ball bearing is inexpensive, but to ensure high-precision rotation, backlash is eliminated.
  • a preload device is required, which may increase the size and cost of the device. Therefore, in the present embodiment, the permanent magnet (first magnet) 21a of the first outer rotor 21 that is the first rotating body is used.
  • a preload is applied to the bearing 33 using a magnetic force acting between the permanent magnet (second magnet) 30a of the first inner rotor 30 serving as the second rotating body. More specifically, as shown in FIG.
  • the axial center B of the permanent magnet 30a of the first inner rotor 30 is set in the axial direction with respect to the axial center A of the permanent magnet 21a of the first outer rotor 21.
  • the layout is shifted to the bottom (lower side in the figure).
  • the permanent magnet 21a is an S pole and the permanent magnet 30a is an N pole, as schematically shown in FIG. 4, the lines of magnetic force are directed from the permanent magnet 30a to the permanent magnet 21a, so that Therefore, the permanent magnet 30a is biased in the axial direction (upward in the figure).
  • the outer ring of the bearing 33 is biased upward via the first inner rotor 30, while the axial position of the inner ring of the bearing 33 is fixed.
  • the backlash of the bearing 33 is eliminated by the strong biasing force.
  • the direct drive motor D1 can be thinned because only one deep groove ball bearing is required without using an expensive four-point contact ball bearing. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on a general bearing steel and mineral oil can be applied.
  • the permanent magnet 30a is bonded and fixed to the back yoke 3 Ob.
  • the permanent magnet 30a is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b is made of low-carbon steel with high magnetism and is chromate-plated to prevent fouling after machining.
  • a resolver rotor is used as a detector for measuring the rotation angle.
  • 34a and 34b are assembled in such a manner that the resolver stators 35 and 36 are attached to the outer periphery of the resolver holder 32 so as to face each other.
  • the high-resolution incremental resolver stator 35 and 1 The absolute resolver stator 36, which can detect where the rotor is located, is arranged in two layers.
  • the resolver holder 32 and the first inner rotor 30 are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35, 36 that are angle detectors. In order to prevent fouling after processing and molding, it is chromated.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Are provided with teeth shifted in phase with respect to the incremental resolver rotor 34a at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the incremental resolver rotor 34a rotates together with the first inner rotor 30, the reluctance between the incremental resolver stator 35 and the magnetic pole changes, and the fundamental wave component of the change in reluctance becomes n cycles in one revolution of the incremental resolver rotor 34a.
  • the change in reluctance is detected, digitalized by the resolver control circuit shown in FIG. 3 and used as a position signal, so that the incremental resolver port 34a, that is, the rotation of the first inner rotor 30 is rotated.
  • the angle (or rotation speed) is detected.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor 21, that is, rotates with the first outer rotor 21, so that the first outer rotor 21 rotates.
  • the corner can be detected through the bulkhead 13.
  • the resolver alone has the bearing 33 without using the parts forming the motor and the uzing. Therefore, the eccentricity adjustment with the resolver alone is performed before the resolver coil is assembled into the housing. Position Since it is possible to adjust the accuracy such as adjustment, there is no need to provide adjustment holes or notches on both flanges of the housing.
  • the main body 12 constitutes a housing.
  • the cylindrical member 23 of the direct drive motor D1 described above extends upward to a position where it is superimposed on the direct drive motor D2, and the inner peripheral surface thereof is a four-point contact ball bearing 19 'used in a vacuum.
  • the outer ring is fitted and fitted with bolts 20 '.
  • the inner ring of the bearing 19 ′ is fitted to the outer periphery of the second outer rotor 21 ′ and is fixed by the bolt 22 ′.
  • the bolt 22 'and the magnetic shield plate 41 extending inward in the radial direction are fastened together.
  • the second outer rotor 21 ′ is rotatably supported with respect to the partition wall 13, and a ring-shaped member 23 ′ that supports the arm A2 (FIG. 1) is fixed by a bolt 24 ′. Further, the bolt 24 'fastens the magnetic shield plate 25, which extends radially inward, to the ring-shaped member 23'.
  • the magnetic shield plates 41, 25 are subjected to nickel plating in order to enhance anti-corrosion and corrosion resistance after press molding the SPCC steel plate, which is a magnetic material.
  • the magnetic shield plates 41 and 25 are interposed between the first outer rotor 21 and the second outer rotor 21 to form a magnetic shield and prevent mutual rotation due to magnetic flux leakage from them. . That is, the magnetic shield plate 25 ′ is fastened to the yoke 21b ′ with the ring-shaped member 23 ′, which is a non-magnetic material, interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated.
  • the magnetic shield plates 41 and 25 can prevent magnetic interference between the rotors, it is possible to achieve a configuration in which the overall shaft length is suppressed while being a biaxial coaxial motor system.
  • the magnetic shield plate 41 prevents foreign matter from being attracted from the outside.
  • the bearing 19 ' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the biaxial coaxial motor of the present invention can be made thinner.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • Roll The moving body uses ceramic balls, and the lubricant uses vacuum grease that does not solidify even under vacuum.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing.
  • a four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used. It can be used under preload conditions, or it can be treated with fluorine coating (DFO) to improve lubricity! ⁇ .
  • DFO fluorine coating
  • the second outer rotor 21 ' mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is made up of a wedge (not shown).
  • Permanent magnet 21a ' is a segment type with a configuration of 32 poles, with 16 N-pole and S-pole magnets alternately made of magnetic metal and divided into poles, each of which has a sector shape.
  • the center of the arc of the inner and outer diameters is the same force.By making the tangent intersection of the circumferential end face closer to the permanent magnet 21a ', the wedge is tightened from the outer diameter side of the yoke 21b' by screwing the permanent magnet 21a ' It is fastened to the yoke 21b '. With this configuration, the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • Permanent magnet 21a ' is a high energy product neodymium (Nd-Fe-B) based magnet, which is coated with nickel to enhance corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel with high magnetism and is plated with nickel in order to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the second outer rotor 21 ' has a surface for fitting and fixing the inner ring of the bearing 19' and the ring-shaped member 23 '.
  • the deep groove ball bearing 19 ' is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′ is tightly fitted or intermediately fitted to the yoke 21b, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • a second stator 29 ' is disposed so as to face the inner peripheral surface of the second outer rotor 21'.
  • the second stator 29 ′ is attached to the upper part of the flange 12 a that extends in the radial direction in the center of the main body 12, and is formed of a laminated material of electromagnetic steel sheets, and each salient pole is insulated. As shown, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the second stator 29 ′ is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is disposed radially inward of the second stator 29'.
  • the second inner rotor 30 ′ is rotatably supported by a deep groove ball bearing 33 ′ with respect to a resolver holder 32 ′ that is bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a knock yoke 30b ′.
  • the permanent magnet 30a ′ has a configuration of 32 poles, like the permanent magnet 21a ′ of the second outer rotor 21 ′, and has 16 magnetic poles each having N poles and S poles alternately. Accordingly, the second inner rotor 30 ′ is rotationally driven by the second stator 2 9 ′ in synchronization with the second outer rotor 21 ′.
  • the axial center of the permanent magnet 30a 'of the first inner rotor 30' is the axial direction with respect to the axial center of the permanent magnet 21a of the first outer rotor 21.
  • the permanent magnet 30a ′ is biased in the axial direction (downward in FIG. 2).
  • the outer ring of the bearing 33 ′ is biased downward via the first inner rotor 30 ′, while the inner ring of the bearing 33 ′ is axially positioned. Therefore, the backlash of the bearing 33 ′ is eliminated by the biasing force.
  • the direct drive motor D2 can be thinned because only one deep groove ball bearing is required without using an expensive four-point contact ball bearing. Since the inside of the partition wall 13 is an atmospheric environment, bearings using grease lubrication based on general bearing steel and mineral oil can be applied.
  • the permanent magnet 30a ' Since the inside of the partition wall 13 is in an atmospheric environment, the permanent magnet 30a 'is bonded and fixed to the back yoke 30b'.
  • the permanent magnet 30a ' is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a 'and 34b' are assembled as detectors for measuring the rotation angle on the inner circumference of the second inner rotor 30 ', and in the form opposite to them, the resolver holder 32' is placed on the outer circumference of the resolver holder 32 '.
  • a high-resolution incremental resolver stator 35 and an absolute resolver stator 36 ′ that can detect the position of the rotor in one rotation are divided into two. Arranged in layers. For this reason, even when the power is turned on, the rotational angle of the absolute resolver rotor 34b 'is known, no return to origin is required, and the electrical phase angle of the magnet with respect to the coil is different. This is possible without using a pole detection sensor.
  • the resolver holder 32 'and the second inner rotor 30' are magnetic bodies so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 ', 36' that are angle detectors. Carbon steel is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor 21 ′, that is, rotates with the rotation angle of the second outer rotor 21 ′.
  • the parts forming the motor, the bearing 33 is provided as a single resolver without using uzing, and therefore, the eccentricity adjustment with the single resolver is performed before being incorporated into the housing. Since it is possible to adjust the accuracy of the resolver coil position, etc., there is no need to provide separate adjustment holes or cutouts on both flanges of the housing.
  • the rotating wheel of the bearing device 19 ′ that is rotatably supported by the second outer rotor 21 ′ is fitted to the rotor yoke 21 b ′, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the driving wheel of the bearing device 19 ′.
  • the incremental resolver rotor 34a ′ has a plurality of slot tooth rows having a constant pitch, and the outer circumference of the incremental resolver stator 35. On the surface, teeth that are out of phase with respect to the incremental resolver rotor 34a ′ at each magnetic pole in parallel with the rotation axis are provided, and a coil is wound around each magnetic pole.
  • Incremental resolver port integrated with second inner rotor 30 ' When the motor 34a rotates, the reluctance with the magnetic pole of the incremental resolver stator 35 changes, and the fundamental wave component of the change in reluctance becomes n cycles in one rotation of the incremental resolver rotor 34a.
  • the rotational angle (or rotational speed) of the incremental resolver rotor 34a ' that is, the second inner rotor 30' Is supposed to be detected.
  • the resolver rotors 34a, 34b and the resolver stators 35, 36 constitute a detector.
  • the magnetic shield plates 25 and 41 are arranged between the first outer rotor 21 and the second outer rotor 21 ', mutual magnetic interference is suppressed. However, it avoids malfunctions such as erroneous driving and rotation.
  • the outer peripheral edge 12b of the flange portion 12a extending between the direct drive motors Dl and D2 in the main body 12 is made of carbon steel, which is a magnetic material, between the first stator 29 and the second stator 29 ′.
  • the magnetic fields that shield each other's magnetic field are included. Functions as a shield.
  • first stator 29 and the second stator 29 ′ are arranged vertically with the flange portion 12 a as the center, and a resolver is arranged on the inside in the radial direction.
  • the main body 12 has a hollow structure, and the flange portion 12a has at least one radial through hole 12d communicating with the center through which the motor wiring is drawn out to the center of the main body 12. It has a structure.
  • at least one notch 12e, 12e is provided at each end of the main body 12, and the resolver wiring is drawn out to the center of the main body 12 through these.
  • FIG. 5 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • the motor control circuit DMC1 for the direct drive motor D1 and the motor control circuit DM C2 for the direct drive motor D2 are each driven from the CPU to a three-layer amplifier (AMP).
  • the signal is output and the drive current is supplied to the direct drive motors Dl and D2 with the three-layer amplifier (AMP) power.
  • the outer rotors 21, 21 ′ of the direct drive motors Dl, D1 rotate independently to move the arms A1, A2 (FIG. 1).
  • the resolver stator 35, 36, 35', 36 'force resolver signal whose rotation angle has been detected as described above is output, which is output to the resolver digital converter (RDC).
  • the CPU that is input after digital conversion in step 1 judges whether or not the outer rotor 21, 21 'has reached the command position, and if it reaches the command position, stops the drive signal to the 3-layer amplifier (AMP). To stop the rotation of the outer rotor 2 1, 21 '. This allows servo control of the outer rotors 21, 21 '.
  • AMP 3-layer amplifier
  • the arm A1 or the like is attached to the wall of the vacuum chamber or the shatter of the vacuum chamber.
  • the absolute resolver stators 36 and 36 'that detect the absolute position of one rotation of the rotating shaft, and the incremental resolver stator 35 and that detect a rotational position with finer resolution are used in this embodiment.
  • a variable reluctance resolver is used, so that the rotational position of the outer rotors 21 and 21, that is, the arms Al and A2, can be controlled with high accuracy.
  • a force detector employing a resolver for detecting the rotation of the inner rotor 30 can be disposed on the atmosphere side inside the partition wall 13, so that a servo motor generally used for high-precision positioning is highly accurate and smooth.
  • 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.
  • FIG. 6 is a cross-sectional view showing a four-axis coaxial motor system that works on a modification of the present embodiment.
  • partition wall holder 113a is hermetically coupled to upper disk portion 110 attached to the upper surface of main body 12 connected in series via O-ring OR, and the outer peripheral surface thereof.
  • the upper end of thin cylinder 113b is TIG welded.
  • the lower end of the thin-walled cylinder 113b is TIG welded to the holder 15 as in the above-described embodiment.
  • the partition wall holder 113a, the thin cylinder 113b and the holder 15 constitute a partition wall. This is commonly used for the four direct drive motors.
  • the upper surface of the disc portion 110 is closed by the lid member 101, and the bearing holder 107 attached to the outer periphery thereof supports the bearing 19.
  • the disk part 110, the lid member 101, and the bearing holder 107 have high corrosion resistance! Use austenitic stainless steel as the material! /
  • the outer peripheral surface of the upper disk part 110 where the bearing holder 107 is attached is located radially inward of the thin cylinder 113b. Therefore, if the bearing holder 107 is removed from the upper disk part 110, the four outer rotors 21, 21 ′ can be removed upward without disassembling the upper disk part 110. Therefore, it is possible to facilitate work that does not require disassembly of the airtight structure during maintenance.
  • the magnetic shield plates 25 'and 25' are arranged between the second outer rotors 21 and 21 at the center, so that mutual magnetic interference is suppressed. This avoids malfunctions such as erroneous driving and companionship.
  • a magnetic shield plate 125 whose outer peripheral force extends in the radial direction to the inside of the thin cylinder 113b is disposed.
  • the magnetic 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 adjacent second outer rotor 21 ′ is affected by the leakage magnetic flux.
  • the force described using the example using the surface magnet type 32-pole 36-slot outer rotor brushless motor is not limited to this type of motor.
  • Applicable, other magnetic pole types such as permanent magnet embedded type, other slot combinations, or in-line It may be a narotor type.
  • a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles and 36 slots
  • the second axis is 24 poles and 27 slots
  • the first axis and the third axis are 32 poles and 3 6 slots. If the two axes and the fourth axis are configured with 24 poles and 27 slots, mutual interference such as generation of thrust in the rotational direction to the rotor and magnetic coupling device due to the magnetic field of each axis can be prevented.
  • Ni-Fe-B neodymium magnet
  • Ni-Fe-B nickel coating
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high temperature demagnetization depending on the temperature conditions during beta-out.
  • System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the force described with reference to the example in which the yoke is made of low-carbon steel and nickel-plated is appropriately changed depending on the material and the environment in which the material is not limited to the surface treatment. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method for fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw, but it may be changed as appropriate depending on the environment in which it is used. May be bonded or other fastening methods.
  • the bearings 19 and 19 have been described using an example of grease grease lubrication for a four-point contact type, but this is not limited to the type, material and lubrication method. It can be changed according to the conditions, rotational speed, etc.In the case of a 4-axis coaxial motor, in order to further increase mechanical rigidity, it may be supported by another bearing or used in an ultra vacuum. In this case, it is possible to use a metal lubricated material that does not emit gas, such as gold or silver plated on the raceway.
  • grease lubrication is provided as bearings 33 and 33 'that rotatably support the rotation side of the angle detector.
  • the bearings 19 and 19 ' may be configured as deep groove ball bearings that similarly apply preload using magnetic force.
  • the inner rotor functioning as a magnetic coupling has been described in the form of using a permanent magnet and a back yoke, but the material and shape of the permanent magnet and the back yoke are not limited to this.
  • the number of poles may not be the same as that of the outer rotor, or the width may not be the same.
  • a salient pole that does not use a permanent magnet is also acceptable.
  • a resolver is used as an angle detector
  • an optical rotary encoder may be used.
  • the material, shape, and manufacturing method of the structural parts and partition walls arranged in and out of the other partition walls are appropriately changed depending on the manufacturing cost, the environment used, the load conditions, the configuration, and the like.
  • the magnetic force coupling used in each rotor and rotation detector generates a thrust in the rotational direction by the magnetic flux that also leaks the magnetic coupling force used in the rotor, stator, and resolver of each axis.
  • magnetic shields for shielding each other's magnetic field are arranged between the rotors of the respective shafts, and the rotors, stators, and resolver forces of the respective shafts interfere with each other's resolvers.
  • the present invention has been described above with reference to the embodiment. However, the present invention should not be construed as being limited to the above-described embodiment, and can be appropriately changed or improved.
  • the direct drive motor of the present embodiment is not limited to a vacuum atmosphere, Can be used in the outside atmosphere.
  • a reactive gas for etching may be introduced into the vacuum chamber after evacuation, but in the direct drive motor of this embodiment, the inside and outside are shielded by the partition walls. Therefore, there is no possibility that the motor coil or the insulating material will be etched.
  • FIG. 7 is a perspective view of a frog redder arm type transport device using a direct drive motor that works in this embodiment.
  • two direct drive motors Dl 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.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed.
  • a wafer transfer arm placed in a vacuum chamber in a semiconductor manufacturing apparatus for example, an apparatus having a plurality of arms such as a scalar type or a frog redder type shown in the figure, particularly requires a plurality of rotary motors. It becomes.
  • the surface area of contact with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc., should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space. [0088] Further, in order to convey the wafer W straight horizontally and with less vibration, it is necessary to firmly hold the moment acting on the tips of the arms Al and A2 by the rotor support portion. In addition, when driving multiple axes in a vacuum environment, if the current rotation position of the arm is not recognized when the power is turned on, the arm Al, A2, etc. will be hit against the wall of the vacuum chamber or the shatter of the vacuum chamber. There is a possibility. A direct drive motor that can meet these requirements will be described.
  • FIG. 8 is a view of the configuration of FIG. 7 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • FIG. 9 is a view of the configuration of FIG. 8 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the internal structure of the direct drive motor will be described in detail with reference to Figs. Since the direct drive motors D1 and D2 have the same basic configuration, only the direct drive motor D1 will be described, and the description of the configuration of the direct drive motor D2 will be omitted by attaching the same reference numerals.
  • a hollow cylindrical main body 10 in which a flange 10a is installed on a surface plate G has a small circular plate 11 connected to its upper end by a bolt.
  • a large disk 12 is fixed by a bolt (not shown).
  • the center of the main body 10 can be used to pass wiring to the stator.
  • the main body 10, small disk 11, and large disk 12 constitute the housing.
  • a lid member 50 covering the opening of the main body 10 is hermetically bolted to the upper surface of the large circular plate 12.
  • the upper part of the partition wall 13 is thin, and the upper end is bent inward in the radial direction, and is attached so as to be sandwiched by the small disk 11 by the disk 12.
  • an O-ring OR is arranged between the members of the direct drive motor D1 as shown in the figure, and therefore the internal space surrounded by the flange 10a of the main body 10, the partition wall 13 and the small disk 11 is External force is also airtight.
  • the partition wall 13 is not necessarily made of a nonmagnetic material.
  • the members may be hermetically sealed by electron beam welding or laser beam welding.
  • the inner ring of a four-point contact ball bearing 14 used in vacuum is fitted to the lower outer periphery of the partition wall 13, and is attached to the partition wall 13 by an inner ring holder 15 fixed to the partition wall 13 with bolts. Yes.
  • the outer ring of the bearing 14 is attached to the outer rotor 16 by an outer holder 17 that fits to the inner periphery of the outer rotor 16 and is bolted to the outer rotor 16.
  • the outer rotor 16 is supported rotatably with respect to the partition wall 13.
  • the bearing 14 is a four-point contact ball bearing that uses a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring to prevent outgassing even in a vacuum.
  • Force that can receive moment in the tilting direction of the outer rotor 16 from the arm A1 Not limited to the contact type, cross rollers, cross balls, cross taper bearings can also be used, and they may be used in a preload state
  • fluorine-based coating DFO may be performed to improve lubricity.
  • An outer rotor magnet 18 is attached to the inner peripheral surface of the outer rotor 16.
  • the outer rotor magnet 18 is composed of 24 poles and 12 magnets of N poles and S poles alternately with magnetic metal force and assembled to the back yoke 19.
  • the back yoke 19 may be made of magnetic stainless steel or iron-plated.
  • the outer rotor magnet 18 is a nickel-plated magnet made of neodymium iron boron. Further, the outer rotor magnet 18 is fastened to the outer rotor 16 with a nonmagnetic metal wedge. Therefore, no resin such as adhesive is disposed, and even when the direct drive motor D1 is disposed in a vacuum, the released gas of the occluded impure molecules can be extremely reduced.
  • a magnetic shield plate 30 is attached to the outer rotor 16 so as to cover the upper part of the outer rotor magnet 18.
  • a stator 29 is disposed on the inner side in the radial direction of the partition wall 13 so as to face the inner peripheral surface of the outer rotor 16.
  • the stator 29 is attached to the flange 10a of the main body 10 by the stator holder 20, and as shown in FIG. 9, 12 coils in each phase are arranged in a cylindrical shape in the order of U phase, V phase, and W phase. Lined up, so it contains a total of 36 coils. This coil is molded by a molding material and integrated. Since the stator 29 is thus arranged on the inner side of the partition wall 13, forced cooling such as water cooling or air cooling can be performed against coil heat generation or the like.
  • the inner rotor 21 is disposed on the radially inner side of the stator 29.
  • the inner rotor 21 is rotatably supported by ball bearings 23 with respect to a resolver holder 22 that is bolted to the outer peripheral surface of the main body 10.
  • An inner rotor magnet 24 is attached to the outer peripheral surface of the inner rotor 21 via a knock yoke 25.
  • the inner rotor magnet 24 is the outer rotor magnet 18
  • 12 magnets with N poles and S poles each having 12 poles, each with magnetic metal force are assembled to the back yoke 25. Accordingly, the inner rotor 21 is rotationally driven by the stator 29 in synchronization with the outer rotor 16.
  • a detection rotor 26 for a detector that measures a rotation angle is assembled on the inner periphery of the inner rotor 21, and resolvers 27 and 28 are attached to the outer periphery of the resolver holder 22 so as to face the rotor.
  • Force In this embodiment, a high-resolution incremental resolver 27 and an absolute resolver 28 capable of detecting the position of the rotor at one rotation are arranged in two layers. For this reason, even when the power is turned on, the rotation angle of the detection rotor 26 can be known, it is not necessary to return to the origin, and the electrical phase angle of the magnet with respect to the coil is ineffective. Rotation angle detection force to be used It is possible to use without using a pole detection sensor.
  • the detection rotor 26 has a plurality of slot tooth rows having a constant pitch, and the outer periphery of the magnetic poles of the stators of the resolvers 27 and 28 The surface is provided with teeth that are shifted in phase with respect to the detection rotor 26 at each magnetic pole in parallel with the rotation axis, and a coil is wound around each magnetic pole.
  • the change in reluctance is detected, digitized by the resolver control circuit shown in FIG. 10 and used as a position signal, so that the rotation angle (or rotation speed) of the detection rotor 26, that is, the inner rotor 21 is detected.
  • the detection rotor 26 and the resolvers 27 and 28 constitute a detector.
  • the inner rotor 21 is rotationally driven by the stator 29 in synchronism with the outer rotor 16. Therefore, if the rotation angle of the inner rotor 21 can be detected, the inner rotor 21 is immediately started. The rotation angle of the outer rotor 16 can be obtained, whereby the drive control of the outer rotor 16 can be performed with high accuracy.
  • FIG. 11 is a block diagram showing a drive circuit of the direct drive motor D1.
  • the motor control circuit DMC outputs a drive signal from the CPU to the three-phase amplifier (AMP), and the three-phase amplifier (AMP) force is also directly driven.
  • the drive current is supplied to the eve motor Dl.
  • the outer rotor 16 of the direct drive motor D1 rotates to move the arm A1.
  • resolver signals are output from the resolvers 27 and 28 that have detected the rotation angle as described above. It is determined whether or not the outer rotor 16 has reached the command position. When the command position is reached, the rotation of the outer rotor 16 is stopped by stopping the drive signal to the three-phase amplifier (AMP). This allows servo control of the outer rotor 16.
  • the current flowing through the three-phase stator coil can be controlled according to the electrical angle of the detection port 26 and the torque command. If a current is passed through the three-phase coils (U phase, V phase, W phase) of the direct drive motor D1, the structure of the coreless motor is used. Therefore, according to Fleming's left-hand rule, the outer rotor 16 and the inner motor 21 are Each can generate substantially the same torque. Originally, if the inner rotor 21 and the outer rotor 16 are not synchronized, each is supported by a rotatable bearing.
  • the direct drive motor D1 supports the moment force with the multipoint contact bearing 14, the wafer W is straightened horizontally even when the highly rigid arm A1 is extended. Can be transported. Since the inner ring of the bearing 14 is assembled to the thick member of the partition wall 13, the acting force hardly acts on the partition wall 13 and is directly applied to the main body 10, so that the risk of the partition wall 13 being broken is extremely high. Can be small.
  • the arm A1 or the like may hit the wall of the vacuum chamber or the shatter of the vacuum chamber.
  • a variable reluctance resolver consisting of an absolute resolver 28 that detects the absolute position of one rotation of the rotating shaft and an incremental resolver 27 that detects a more precise rotational position is adopted. Therefore, the rotational position of the outer rotor 16, that is, the arm A 1 can be controlled with high accuracy.
  • FIG. 12 is a diagram showing a modification of the present embodiment.
  • the force obtained by arranging two sets (four in total) of direct drive motors Dl and D2 in series is the same as the configuration shown in FIG.
  • the same parts are denoted by the same reference numerals, and description thereof is omitted.
  • the direct drive motor of the present embodiment since the inner rotor is arranged on the radially inner side of the stator, the dimension in the axial direction can be reduced (thin), so four pieces are conveyed in series as shown in FIG. Even if the apparatus is configured, a compact configuration in the height direction can be provided. In addition, the thin structure increases rigidity and avoids the risk of resonance, etc., which is advantageous for multi-axis use and can reduce the difference in the control constant of each outer rotor. Furthermore, by using a stack of direct drive motors of the same shape, it is possible to replace only the direct drive motor in the event of a failure, and the maintenance is good. In addition, the inventory of replacement parts can be minimized. FIG.
  • FIG. 13 is a cross-sectional view similar to FIG. 8 of a direct drive motor that can be used in the transport device shown in FIG. 7 and that works on the second embodiment. Since the direct drive motors Dl and D2 have the same basic configuration, only the direct drive motor D1 will be described, and the description of the configuration of the direct drive motor D2 will be omitted by attaching the same reference numerals.
  • a hollow cylindrical main body 110 in which a flange 110a is installed on a surface plate G has a small disc 111 connected to its upper end by a bolt.
  • a large circular plate 112 is fixed to the outer peripheral side of the upper surface of the small circular plate 111 with a bolt (not shown).
  • the center of the main body 110 can be used to pass wiring to the stator.
  • the main body 110, the small disk 111, and the large disk 112 constitute a housing.
  • the cylindrical partition wall 113 made of stainless steel (SUS316L, etc.), which is a non-magnetic material, is inserted into the cylindrical mounting portion 110b formed on the flange 110a of the main body 110 so that the non-magnetic material is made of stainless steel. It is attached coaxially.
  • the upper part of the partition wall 113 is thin, and the upper end is bent inward in the radial direction, and is attached to the small disk 111 together with the disk 112.
  • an O-ring OR is arranged between the members of the direct drive motor D1 as shown in the figure, and therefore the internal space surrounded by the flange 110a of the main body 110, the partition wall 113, and the small disk 111 is External force is also airtight.
  • the partition wall 113 is not necessarily made of a nonmagnetic material.
  • the members may be hermetically sealed by electron beam welding or laser beam welding.
  • the inner ring of a four-point contact ball bearing 114 used in vacuum is fitted to the lower outer periphery of the partition wall 113, and is attached to the partition wall 113 by an inner ring holder 115 fixed to the partition wall 113 with bolts.
  • the outer ring of the bearing 114 is attached to the outer rotor 116 by an outer holder 117 that fits to the inner periphery of the outer rotor 116 and is fixed to the outer rotor 116 with a bolt. That is, the outer rotor 116 is supported rotatably with respect to the partition wall 113.
  • the bearing 114 is a four-point contact ball bearing that uses soft metal such as gold and silver plated on the inner ring and outer ring to release metal even in vacuum, and is a four-point contact ball bearing. Force that can receive moment in the tilting direction of the outer rotor 116 from the arm A1 Not limited to the four-point contact type, cross rollers, cross balls, and cross taper bearings can also be used and may be used in a preload state Fluorine-based coating treatment for improving lubricity ( DFO) may be performed.
  • DFO lubricity
  • An outer rotor magnet 108 for magnetic coupling is attached to the center of the inner peripheral surface of the outer rotor 116.
  • the outer rotor magnet 108 for magnetic coupling has a structure of 32 poles, and has a magnetic metal force in which 16 pieces of N pole and S pole magnets are alternately arranged, and is assembled to the knock yoke 109.
  • the back yoke 109 which is a magnetic coupling rotor fitted and fixed to the outer rotor 116, may be magnetic stainless steel or iron-plated nickel.
  • the outer rotor magnet 108 for magnetic coupling uses a nickel-plated magnet made of neodymium iron boron.
  • the outer rotor magnet 108 for magnetic coupling has a non-magnetic metal wedge fastened to the outer rotor 116 with a screw. Therefore, no grease such as adhesive is disposed, and even when the direct drive motor D1 is disposed in a vacuum, the released gas of the occluded impure molecules can be extremely reduced.
  • a magnetic shield plate 103 is attached to the outer motor 116 so as to cover the upper part of the outer rotor magnet 108 for magnetic coupling.
  • an outer rotor magnet 118 is attached to the upper part of the inner peripheral surface of the outer rotor 116.
  • the outer rotor magnet 118 is composed of a magnetic metal in which 16 poles of N poles and S poles are alternately arranged in a 32 pole configuration, and is assembled to the back yoke 119.
  • the back yoke 119 may be magnetic stainless steel or iron plated with nickel.
  • the outer rotor magnet 118 uses a nickel-plated magnet made of neodymium iron boron. Further, the outer rotor magnet 118 has a non-magnetic metal wedge fastened to the outer rotor 116 with screws.
  • a magnetic shield plate 130 is attached to the lower surface of the disc 112 so as to cover the upper portion of the outer rotor magnet 118.
  • a stateer 129 is arranged on the inner side in the radial direction of the partition wall 113 so as to face the outer rotor magnet 118.
  • the stator 129 is attached to the main body 110.
  • the stator 129 has a cylindrical shape with 3 slots for the U phase, 3 slots for the V phase, and 3 slots for the W phase. Slots are arranged.
  • a magnetic shield plate 102 is attached to the outer rotor 116 so as to cover the top of the stator 129.
  • This 32-pole 36-slot motor has a slot configuration that is four times that of a known technology motor with a small number of 8-poles and 9-slots.
  • the in-phase and the same pole are arranged on the diagonal line of the outer rotor 116.
  • the magnetic attraction force is unbalanced. 1S Radial force is generated in the bearing that supports it, and vibration may occur due to the rigidity of the bearing 114. Since the unbalanced force is canceled by the same homologous poles on the diagonal line, the bearing 114 that supports the outer rotor 116 has a feature that suppresses the occurrence of vibration without using the unbalanced force.
  • the magnetic coupling inner rotor magnet 101 is disposed on the radially inner side of the partition wall 113 so as to face the magnetic coupling outer rotor magnet 108.
  • the inner rotor magnet 101 for magnetic coupling is attached via a back yoke 125 to an inner rotor 121 that is rotatably supported via a bearing 123 with respect to a cylindrical mounting portion 110b of the flange 110a of the main body 110.
  • the inner rotor magnet 101 for magnetic coupling has a configuration of 32 poles as in the case of the outer rotor magnet 108 for coupling, and 16 magnets each having N poles and S poles are alternately arranged.
  • the inner rotor magnet 101 for magnetic coupling and the outer rotor magnet 108 for magnetic coupling are fixed in relative rotation by the magnetic force attracting each other with the opposite poles facing each other with the partition wall 113 interposed therebetween, that is, between the two magnets.
  • the inner rotor 121 rotates in synchronization with the knock yoke 119, that is, the outer rotor 116, based on the magnetic coupling force acting in a non-contact manner.
  • a detection rotor 126 for a detector for measuring a rotation angle is assembled on the inner periphery of the inner rotor 121, and resolvers 127 and 128 are mounted on the outer periphery of the main body 110 so as to face the rotor.
  • the high-resolution incremental resolver 127 and the absolute resolver 128 that can detect the position of the rotor in one rotation are arranged in two layers.
  • detection The rotor 126 has a plurality of slot tooth rows having a constant pitch, and the magnetic poles of the stators of the resolvers 127 and 128 are shifted in phase with respect to the detection rotor 126 by each magnetic pole in parallel with the rotation axis. Teeth are provided and a coil is wound around each magnetic pole.
  • the change in reluctance is detected, digitized by the resolver control circuit shown in FIG. 10 and used as a position signal, so that the rotation angle (or rotation speed) of the detection rotor 126, that is, the inner rotor 121 is determined. It comes to detect.
  • the detection rotor 126 and the resolvers 127 and 128 constitute a detector.
  • the inner rotor 121 is rotationally driven in synchronization with the outer rotor 116 via a magnetic coupling. Therefore, if the rotation angle of the inner rotor 121 can be detected, That force can also immediately determine the rotation angle of the outer rotor 116. Further, the direct drive motor D1 of the present embodiment is servo-controlled by a drive circuit as shown in FIG.
  • the magnetic shield plates 102 and 103 are configured so that the magnetic field generated between the stator 129 and the outer rotor magnet 118 is attracted between the magnetic coupling inner rotor magnet 101 and the magnetic coupling outer rotor magnet 108. It is provided so as not to disturb the force and affect the magnetic coupling action.
  • the stator 129 and the outer rotor magnet 118 have 32 magnetic poles, and the magnetic coupling inner rotor magnet 101 and the magnetic coupling outer rotor magnet 108 also have 32 magnetic poles, each has the same number of magnetic poles.
  • the magnetic shield plates 102 and 103 are particularly effective when the magnetic poles of the stator 129 and the outer rotor magnet 118 are different from the magnetic poles of the magnetic coupling inner rotor magnet 101 and the magnetic coupling outer rotor magnet 108. is there.
  • the resolver 127, 128 detects the angular position and controls the drive of the direct drive motor D1. Will cause the outer rotor 116 to rotate abnormally. There is a risk. This is called resonance of the magnetic coupling system.
  • the partition 113 is used to avoid an abnormal operation.
  • FIG. 14 is a schematic diagram showing a state where eddy current loss occurs in the partition wall 113.
  • the outer rotor 116 is attached with the north pole of the outer magnet 108 for magnetic coupling
  • the inner rotor 121 is fitted with the south pole of the inner magnet 101 for magnetic coupling. It is assumed that a magnetic coupling is formed by being opposed to each other with the partition wall 113 therebetween.
  • FIG. 15 is a schematic diagram similar to FIG. 14 showing three magnets arranged in the direction, and shows a state in which a braking force against rotation is generated using eddy current.
  • an eddy current is generated in the partition wall 113 to generate a magnetic flux according to the principle shown in FIG.
  • the magnetic flux generated by the eddy current generates a repulsive force in the traveling direction of the magnet 108 provided in the outer rotor 116.
  • This eddy current increases as the rate of change of magnetic flux increases. Therefore, the eddy current increases as the magnetic permeability (magnetic resistance) of the partition wall 113 and the magnetic flux density and frequency of the magnet 108 increase.
  • the partition wall 113 has a magnetic resistance value and an electrical resistance value specific to the material and shape force, and the product of the square of the electrical resistance value and the eddy current is the eddy current loss of the partition wall 113. Therefore, due to the eddy current loss of the partition wall 113 depending on the frequency, a damping resistance of the outer rotor 116 occurs during the magnetic coupling operation. For example, when the outer rotor 116 vibrates, it has an effect of attenuating this.
  • FIG. 16 is a block diagram of the motor control system when there is no partition
  • FIG. 17 is a block diagram of the motor control system when there is a partition.
  • the outer rotor 116 receives a reaction force only by the spring stiffness Kf of the magnetic coupling, and when there is a partition 113, the spring stiffness Kf of the magnetic coupling and the damping of the partition are shown in Fig. 17. It can be seen that the reaction force is based on the resistance Cf.
  • the transfer function of the motor speed co rm with respect to the motor torque Te is expressed by the equation (1), and the resonance frequency and the attenuation rate thereof are expressed by the equations (2), (3), (4 ), (5).
  • Jm is the motor inertia
  • Jr is the resolver inertia
  • Kf is the spring force of the magnetic force coupling
  • Cf is the damping resistance of the magnetic coupling
  • ⁇ a is the resonance frequency
  • ⁇ ⁇ is the anti-resonance frequency
  • ⁇ and ⁇ are the damping rates is there.
  • the peak value can be made small by making it. Conventionally, this is done by the motor controller. Oscillation could be prevented by using an angle signal that uses a notch filter for the resonance frequency. However, if the characteristics of the notch filter are too strong, the angle signal in the vicinity of the resonance frequency may not be controlled. On the other hand, by using the eddy current loss of the partition wall, the resonance frequency peak value can be controlled by reducing the peak value of the resonance frequency.
  • the spring stiffness of the magnetic coupling is expressed as shown in Fig. 20.
  • the biaxial coaxial direct drive motor according to the present invention can reduce the gain peak of the resonance frequency of the magnetic coupling by utilizing the eddy current loss of the partition wall.
  • eddy current loss leads to heat generation of the partition wall, it is desirable to determine the material and shape of the partition wall considering heat generation.
  • damping resistance together with the effect of the weak notch filter, it is possible to enable control with less heat generation.
  • 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.
  • reactive gas for etching may be introduced into the vacuum chamber after evacuation, but in the direct drive motor of this embodiment, the inside and outside are shielded by the partition walls. Therefore, there is no possibility that the motor coil or the insulating material will be etched.
  • FIG. 21 is a perspective view of a frog redder arm type conveyance device using a direct drive motor that works in this embodiment.
  • two direct drive motors Dl 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.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed.
  • a wafer transfer arm placed in a vacuum chamber in a semiconductor manufacturing apparatus for example, an apparatus having a plurality of arms such as a scalar type or a frog redder type shown in the figure, particularly requires a plurality of rotary motors. It becomes.
  • the surface area of contact with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc., should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space.
  • a surface magnet type 32-pole 36-slot outer rotor brushless type direct drive motor is used.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good.
  • FIG. 22 is a view of the configuration of FIG. 21 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the internal structure of the two-axis motor system will be described in detail with reference to FIG. First, the direct drive motor D1 will be described.
  • a hollow cylindrical main body 12 fitted in the central opening 10a of the disk 10 installed on the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition wall 13 attached to the upper end thereof.
  • the center of the main body 12 can be used to pass wiring to the stator.
  • the main body 12 and the disk 10 constitute a housing.
  • the partition wall 13 is made of stainless steel, which is a non-magnetic material, and extends from the peripheral edge of the partition wall 13 through the direct drive motors Dl and D2 in the axial direction. It consists of a cylindrical part (tubular part) 13b that is thinner than the existing disk part 13a. Therefore, the partition wall 13 is commonly used for the direct drive motors Dl and D2. The lower end of the cylindrical portion 13b is joined to the holder 15 so that it can be sealed by TIG welding, and the holder 15 is fixed to the disc 10 with bolts 16.
  • the contact surface between the holder 15 and the disk 10 is provided with a groove force that fits the seal member. After the seal member is fitted into the groove, the holder 15 and the disk 10 are fastened by the bolt 16. , Atmospheric side force is separated from the fastening part.
  • the partition wall 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance, and has a low magnetic property, and the holder 15 is made of SUS316 as well because of its weldability with the partition wall 13.
  • the main body 12 and the partition wall 13, the partition wall 13 and the holder 15 are hermetically joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are respectively O-ring OR. Is airtight. Therefore, the internal space surrounded by the disc 10, the main body 12, and the partition wall 13 is airtight from the outside.
  • the partition wall 13 is not necessarily made of a nonmagnetic material. Also, instead of using O-ring OR to seal the air, the parts may be sealed by electron beam welding or laser beam welding.
  • a bearing holder 17 is fixed with bolts 18 on the outer peripheral upper surface of the disc 10.
  • the bearing holder 17 is fitted with an outer ring of a four-point contact ball bearing 19 that is used in a vacuum, and is fixed by bolts 20.
  • the inner ring of the bearing 19 is fitted to the outer periphery of the first outer rotor 21 and is fixed by bolts 22. That is, the first outer rotor 21 is rotatably supported with respect to the partition wall 13, and a cylindrical member 23 that supports the arm A 1 (FIG. 21) is fixed by the bolt 24.
  • the bolt 24 fastens the magnetic shield plate 25 extending inward in the radial direction together with the cylindrical member 23.
  • the disc 10 and the bearing holder 17 are made of austenitic stainless steel having high corrosion resistance.
  • the disc 10 also serves as a fitting and fixing device with the surface plate G that is a chamber, and has a sealing device on its lower surface.
  • a groove 10b is provided to fill the O-ring OR.
  • the magnetic shield plate 25 is subjected to nickel plating in order to enhance the anti-corrosion and corrosion resistance after press-forming the SPCC steel plate, which is a magnetic material.
  • the effect of the bearing 19, which will be described later, is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing for the direct drive motor D1 is required, so the two-axis coaxial motor system of the present invention can be made thinner.
  • the bearing 19 is made of martensite stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so as not to release outgas even in vacuum, or a four-point contact ball. Because it is a bearing, it can receive a moment in the direction in which the first outer rotor 21 tilts from the arm A1, but it is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. Yes, it can be used under preload conditions, or fluorine film treatment (DFO) can be performed to improve lubricity! ⁇ .
  • DFO fluorine film treatment
  • the first outer rotor 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material for forming a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It consists of a wedge (not shown).
  • Permanent magnet 21a is composed of 32 poles, N poles, Each of the 16 S-pole magnets is made of magnetic metal, and is divided into segments. The individual shape is a sector.
  • the permanent magnet 21a is a neodymium (Nd—Fe—B) based magnet having a high energy product, and has a nickel coating to enhance corrosion resistance.
  • the yoke 21b is made of a low-carbon steel having high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the first outer rotor 21 has a surface for fitting and fixing the inner ring of the bearing 19 and the cylindrical member 23.
  • the four-point contact ball bearing 19 is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 which is a rotating ring is an interference fit or an intermediate fit to the yoke 21b which is easy to obtain processing accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring of the bearing 19, which is a fixed ring, is fitted to the austenitic stainless steel bearing holder or aluminum boss to prevent the bearing 19 from rotating and the friction torque from increasing due to temperature rise. ing.
  • the first stator 29 is disposed so as to face the inner peripheral surface of the first outer rotor 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12.
  • the first stator 29 is formed of a laminated material of electromagnetic steel plates and is insulated from each salient pole. As a process, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • the first inner rotor 30 is disposed on the radially inner side of the first stator 29.
  • the first inner rotor 30 is rotatably supported by a ball bearing 33 with respect to a resolver holder 32 that is bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock 30b.
  • Permanent magnet 30a is composed of 32 poles in the same way as permanent magnet 21a of first outer rotor 21. 16 N pole and S pole magnets are alternately magnetized. Made of metal. Accordingly, the first inner rotor 30 is rotated in synchronism with the first outer rotor 21 driven by the first stator 29.
  • the bearing 33 that rotatably supports the first inner rotor 30 is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D1 because only one bearing is required. Since the interior of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a is bonded and fixed to the back yoke 30b.
  • Permanent magnet 30a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 30b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a and 34b are assembled as detectors for measuring the rotation angle on the inner periphery of the first inner rotor 30, and the resolver stator 35 is disposed on the outer periphery of the resolver holder 32 so as to face it.
  • the high-resolution incremental resolver stator 35 and the absolute resolver stator 36 that can detect the position of the rotor in one rotation are arranged in two layers. /!
  • the resolver holder 32 and the first inner rotor 30 are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35, 36 that are angle detectors. In order to prevent fouling after processing and molding, it is chromated.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Incremental with each magnetic pole parallel to the rotation axis Teeth that are out of phase with respect to the mental resolver rotor 34a are provided, and a coil is wound around each magnetic pole.
  • the incremental resolver rotor 34a rotates together with the first inner rotor 30, the reluctance between the incremental resolver stator 35 and the magnetic pole changes, and the fundamental wave component of the change in reluctance is n cycles in one revolution of the incremental resolver rotor 34a.
  • the change in reluctance is detected, digitalized by the resolver control circuit shown in FIG. 23, and used as a position signal, so that the rotational angle of the incremental resolver rotor 34a, that is, the first inner rotor 30 is (Or rotation speed) is detected.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor 21, that is, rotates with the first outer rotor 21, so that the first outer rotor 21 rotates.
  • the corner can be detected through the bulkhead 13.
  • the resolver alone has the bearing 33 without using the parts forming the motor and the uzing, and therefore, the eccentricity adjustment with the resolver alone is performed before the resolver coil is assembled into the housing. Since accuracy adjustment such as position adjustment can be performed, there is no need to provide adjustment holes or notches on both flanges of the housing.
  • the main body 12 constitutes a housing.
  • the cylindrical member 23 of the direct drive motor D1 described above extends upward to a position where it is superimposed on the direct drive motor D2, and the inner peripheral surface thereof is a four-point contact ball bearing 19 'used in a vacuum.
  • the outer ring is fitted and fitted with bolts 20 '.
  • the inner ring of the bearing 19 ′ is fitted to the outer periphery of the second outer rotor 21 ′ and is fixed by the bolt 22 ′.
  • the bolt 22 'and the magnetic shield plate 41 extending inward in the radial direction are fastened together.
  • the second outer rotor 21 ′ is rotatably supported with respect to the partition wall 13, and a ring-shaped member 23 ′ that supports the arm A 2 (FIG. 21) is fixed by a bolt 24 ′. Further, the bolt 24 'fastens the magnetic shield plate 25 extending inward in the radial direction together with the ring-shaped member 23'.
  • the magnetic shield plates 41 and 25 ' are subjected to nickel plating in order to enhance the anti-corrosion and corrosion resistance after press molding the SPCC steel plate, which is a magnetic material.
  • Magnetic shield plate 41, 2 5 a magnetic shield is formed between the first outer rotor 21 and the second outer rotor 21 to prevent mutual rotation due to magnetic flux leakage from them. That is, the magnetic shield plate 25 ′ is fastened to the yoke 21b ′ with the ring-shaped member 23 ′, which is a non-magnetic material, interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated.
  • the magnetic shield plates 41 and 25 can prevent magnetic interference between the rotors, it is possible to achieve a configuration in which the overall shaft length is suppressed while being a biaxial coaxial motor system.
  • the magnetic shield plate 41 prevents foreign matter from being attracted from the outside.
  • Bearing 19 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing.
  • a four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used. It can be used under preload conditions, or it can be treated with fluorine coating (DFO) to improve lubricity! ⁇ .
  • DFO fluorine coating
  • the second outer rotor 21 ' mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is made up of a wedge (not shown).
  • Permanent magnet 21a ' is a segment type with a configuration of 32 poles, with 16 N-pole and S-pole magnets alternately made of magnetic metal and divided into poles, each of which has a sector shape. The center of the arc of the inner and outer diameter is the same. It is fastened to the yoke 21b '. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • Permanent magnet 21a has a high energy product, neodymium (N d-Fe-B) magnet with nickel coating to enhance corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel with high magnetism and is plated with nickel in order to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the second outer rotor 21 ' has a surface for fitting and fixing 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 its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′ is tightly fitted or intermediately fitted to the yoke 21b, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring is made into a clearance fit with a bearing holder made of austenitic stainless steel or an aluminum boss, thereby preventing a decrease in rotational accuracy of the bearing 19 'and an increase in friction torque due to a temperature rise.
  • a second stator 29 ' is disposed so as to face the inner peripheral surface of the second outer rotor 21'.
  • the second stator 29 ' is attached to the upper part of the flange 12a that extends in the radial direction in the center of the main body 12, and is formed of a laminated material of electromagnetic steel plates, and each salient pole is insulated. As shown, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the second stator 29 ' is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is arranged on the radially inner side of the second stator 29'.
  • the second inner rotor 30 ′ is rotatably supported by a ball bearing 33 ′ with respect to a resolver holder 32 ′ bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a back yoke 30b ′.
  • the permanent magnet 30a ′ has a configuration of 32 poles, like the permanent magnet 21a ′ of the second outer rotor 21 ′, and has 16 magnetic poles each having N poles and S poles alternately. Accordingly, the second inner rotor 30 ′ is rotationally driven by the second stator 29 ′ in synchronization with the second outer rotor 21 ′.
  • the bearing 33 'that rotatably supports the first inner rotor 30' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D2 because only one bearing is required. Since the interior of the partition wall 13 is an atmospheric environment, grease lubrication is performed using a base oil of general bearing steel and mineral oil. Can be used.
  • the permanent magnet 30a ′ Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a ′ is bonded and fixed to the back yoke 30b ′.
  • the permanent magnet 30a ' is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a 'and 34b are assembled as detectors for measuring the rotation angle on the inner circumference of the second inner rotor 30', and are arranged opposite to the outer circumference of the resolver holder 32 '.
  • the resolution of the resolver stator 35 ′, 36 ′ is high resolution incremental resolver stator 35, and the absolute resolver stator 36 ′ that can detect the position of the rotor in one rotation.
  • the rotational angle of the absolute resolver rotor 34b ' is known, no return to origin is required, and the electrical phase angle of the magnet with respect to the coil is different. This is possible without using a pole detection sensor.
  • the resolver holder 32 'and the second inner rotor 30' are magnetic bodies so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 'and 36' which are angle detectors. Carbon steel is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor 21 ′, that is, rotates with the rotation angle of the second outer rotor 21 ′.
  • the parts forming the motor, the bearing 33 is provided as a single resolver without using uzing, and therefore, the eccentricity adjustment with the single resolver is performed before being incorporated into the housing. Since it is possible to adjust the accuracy of the resolver coil position, etc., there is no need to provide separate adjustment holes or cutouts on both flanges of the housing.
  • the incremental resolver rotor 34a ′ has a plurality of slot tooth rows having a constant pitch.
  • teeth that are shifted in phase with respect to the incremental resolver rotor 34a 'by each magnetic pole in parallel with the rotation axis are provided, and the coil is wound around each magnetic pole.
  • the incremental resolver rotor rotor 34a rotates together with the second inner rotor 30 ', the reluctance between the magnetic poles of the incremental resolver stator 35 changes, and the fundamental wave component of the reluctance change is changed by one rotation of the incremental resolver rotor 34a'.
  • the change in reluctance is detected so that there are n cycles, digitalized by the resolver control circuit shown in FIG. 23 and used as a position signal, so that the incremental resolver rotor 34a ′, that is, the second inner rotor 30
  • the rotation angle (or rotation speed) of ' is detected.
  • the magnetic shield plates 25 and 41 are arranged between the first outer rotor 21 and the second outer rotor 21 ', so that mutual magnetic interference is prevented. Suppresses and avoids malfunctions such as erroneous driving and surroundings.
  • the outer peripheral edge 12b of the flange portion 12a extending between the direct drive motors D1 and D2 in the main body 12 is made of carbon steel, which is a magnetic material, between the first stator 29 and the second stator 29 ′. So that the first outer rotor 21 or the second outer rotor 21 does not generate a thrust in the wrong rotation direction due to the influence of the leakage magnetic flux! / Functions as a magnetic shield.
  • the first stator 29 and the second stator 29 ' are vertically arranged around the flange portion 12a, and the resolver is arranged radially inward thereof.
  • the body 12 has a hollow structure.
  • the flange portion 12a is provided with at least one radial through hole 12d communicating with the center through which the motor wiring is drawn out to the center of the main body 12.
  • at least one notch 12e, 12e is provided at each end of the main body 12, and the resolver wiring is drawn out to the center of the main body 12 through these.
  • the angle of the stator and resolver can be adjusted. Therefore, if a separate facility for rotationally driving the reference outer rotor is prepared, the angle of the resolver relative to the stator can be adjusted with high accuracy by setting the main body 12 incorporating the stator and resolver in the facility. Therefore, it is possible to prevent the angle positioning accuracy from being lowered due to the deviation of the commutation, and to improve the compatibility of the drive control circuit with the two-axis coaxial motor of the present invention.
  • FIG. 24 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • the drive signal is output, and the drive current is supplied to the direct drive motors Dl and D2 with a three-layer amplifier (AMP) force.
  • AMP three-layer amplifier
  • the resolver signal is output from the resolver stator 35, 36, 35, 36, which has detected the rotation angle as described above, and is output to the resolver digital converter (RDC).
  • the CPU input after digital conversion judges whether or not the outer rotor 21, 21 'has reached the command position, and when it reaches the command position, it stops the drive signal to the 3-layer amplifier (AMP). Stop rotation of outer ports 21, 21 '. This enables servo control of the outer rotors 21, 21 '.
  • FIG. 25 is a cross-sectional view similar to FIG. 22 that works on the second embodiment. With respect to the present embodiment, different parts from those of the embodiments of FIGS. 22 to 24 will be described, and parts having similar functions will be denoted by the same reference numerals and description thereof will be omitted. In the configuration shown in FIG. 25, the inner rotor, the stator, and the resolver are shown as a simple integrated force. These are the same as those shown in FIG.
  • bolts are used for stepped portion 11 Oa of upper disc portion 110 attached to the upper surface of cylindrical main body 112, and annular portion 113a is hermetically sealed via O-ring OR.
  • the lower portion of the annular portion 113a is a flange portion 113c that is thin and extends radially outward.
  • the upper end of the thin cylindrical portion 113b is TIG welded to the bent outer edge.
  • the thickness of the attachment portion of the annular portion 113a is thicker than the thickness of the flange portion 113c and the thin cylindrical portion 113b.
  • the lower end of the thin cylindrical portion 113b is TIG welded to the holder 15 in the same manner as in the above embodiment.
  • the annular portion 113a, the flange portion 113c, the thin cylindrical portion 113b, and the holder 15 constitute a partition wall 113.
  • the disc part 110, the main body 112 and the disc 10 constitute a nosing.
  • the upper surface of the upper disc part 110 is closed by the lid member 101, and the bearing holder 107 attached to the outer periphery thereof 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 disk 10.
  • the upper disk portion 110, the lid member 101, and the bearing holder 107 are made of high corrosion resistant V-austenite stainless steel.
  • the mounting outer peripheral surface of the upper disc portion 110 of the bearing holder 107 is located on the inner side in the radial direction from the thin cylindrical portion 113b. The two outer rotors 21 and 21 ′ can be removed upward without disassembling the upper disk part 110. Therefore, it is possible to facilitate work that does not require disassembly of the airtight structure during maintenance.
  • the thickness of the flange portion (connecting portion) 113c is thinner than the thickness of the annular portion (attachment portion) 113a of the partition wall 113, so that the dimensional accuracy, mechanical accuracy, and temperature change Even if an axial expansion / contraction stress is generated in the partition wall 113 due to the deformation, the flange portion 113c can be deformed to relieve the axial stress and bending stress of the partition wall 113, thereby causing a seal failure or breakage. Etc. can be prevented. Further, since it is not necessary to process the annular portion 113a and the upper disk portion 110 and the main body 12 to which the annular portion 113a is attached with high precision, a lower cost direct drive motor can be provided.
  • FIG. 26 is a cross-sectional view similar to FIG. 22 that works on the third embodiment. With respect to the present embodiment, different parts from the embodiment of FIG. 25 will be described, and parts having similar functions will be denoted by the same reference numerals and description thereof will be omitted.
  • the inner rotor, the stator, and the resolver are shown as a simple integrated force. These are the same as those shown in FIG.
  • the annular portion 213a is hermetically coupled to the step portion 11 Oa of the upper disc portion 110 attached to the upper surface of the cylindrical main body 112 through an O-ring OR using bolts. is doing.
  • the lower portion of the annular portion 213a is a thin plate-like flange portion 213c extending radially outward in a wave shape, and is formed by TIG welding the upper end of the thin cylindrical portion 213b to the bent outer edge.
  • the thickness of the attachment portion of the annular portion 213a is thicker than the thickness of the flange portion 213c and the thin cylindrical portion 213b.
  • the lower end of the thin-walled cylindrical portion 213b is TIG welded to the holder 15 as in the above-described embodiment.
  • the annular portion 213a, the flange portion 213c, the thin cylindrical portion 213b, and the holder 15 constitute a partition wall 213. Further, the disk part 110, the main body 112, and the disk 10 constitute a housing.
  • the thickness of the flange portion (connecting portion) 213c is thinner than the thickness of the annular portion (attachment portion) 213a of the partition wall 213, and further, the annular portion 213a Thin cylinder Since the flange portion 213c that connects the portion 213b has a waveform, the flange portion 213c does not move even when axial expansion and contraction stress occurs in the partition wall 213 due to dimensional accuracy, mechanical accuracy, and temperature change. By deforming, the axial stress and bending stress of the partition wall 213 can be relaxed, thereby preventing a seal failure or breakage. Further, since it is not necessary to process the annular portion 213a and the upper disk portion 110 and the main body 12 to which the annular portion 213a is attached with high accuracy, a lower cost direct drive motor can be provided.
  • FIG. 27 is a cross-sectional view similar to FIG. 22 that works on the fourth embodiment.
  • FIG. 25 different parts from the embodiment of FIG. 25 will be described, and parts having similar functions will be denoted by the same reference numerals and description thereof will be omitted.
  • the inner rotor, the stator, and the resolver are shown as a simple integrated force. These are the same as those shown in FIG.
  • the annular portion 313a is hermetically coupled to the step portion 11 Oa of the upper disk portion 110 attached to the upper surface of the cylindrical main body 112 through an O-ring OR using bolts. is doing.
  • the cylindrical portion 313e has a shape in which a small cylindrical portion 313c and a large cylindrical portion 313b having substantially the same thickness are connected by a flange portion 313d.
  • the upper portion of the cylindrical portion 313c is an inner peripheral surface of the annular portion 313a. TIG welded.
  • 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 as in the above-described embodiment.
  • the annular portion 313a, the tubular portion 313e, and the holder 15 constitute a partition wall 313.
  • the disk portion 110, the main body 112, and the disk 10 constitute a housing.
  • the thickness of the cylindrical portion 313e is thinner than the thickness of the annular portion (attachment portion) 313a of the partition wall 313, which causes dimensional accuracy, mechanical accuracy, and temperature change. Therefore, even when an axial expansion / contraction stress is generated in the partition wall 313, the flange portion 313d is deformed, so that the axial stress and bending stress of the partition wall 313 can be relaxed. Destruction can be prevented. Further, since it is not necessary to process the annular portion 313a and the upper disk portion 110 and the main body 12 to which the annular portion 313a is attached with high accuracy, a lower cost direct drive motor can be provided.
  • the force described using the example using the surface magnet type 32-pole 36-slot outer rotor brushless motor is not limited to this type of motor. Any brushless motor can be applied, and other magnetic pole types, for example, a permanent magnet embedded type, other slot combinations, or an inner rotor type may be used. Further, as a countermeasure against interference of each axis, a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles and 36 slots
  • the second axis is 24 poles and 27 slots
  • the first and third axes are 32 poles and 3 6 slots. If the two axes and the fourth axis are configured to have 24 poles and 27 slots, mutual interference such as generation of thrust in the rotational direction to the rotor and magnetic coupling device due to the magnetic field of each axis can be prevented.
  • a neodymium (Nd-Fe-B) magnet was used as the rotor permanent magnet, and nickel coating was used as an example for coating to improve corrosion resistance.
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high temperature demagnetization depending on the temperature conditions during beta-out System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the yoke is made of low-carbon steel and explained with an example in which nickel plating is applied.
  • This material is not limited to the surface treatment and is appropriately changed depending on the environment used. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method for fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw, but it may be changed as appropriate depending on the environment in which it is used. May be bonded or other fastening methods.
  • bearings 19 and 19 have been described using an example of grease grease lubrication for four-point contact ball bearings.
  • this is not limited to this type, material, and lubrication method. It can be changed as appropriate depending on conditions, rotational speed, etc., and it can be a cross roller bearing.
  • it can be supported by another bearing to further increase mechanical rigidity. Good and cannot use multi-point contact bearings when rotating at high speed.
  • bearings that support the rotor of each shaft and other bearings may be structured to apply preload as deep groove ball bearings as angular bearings. It is also possible to use a metal-lubricated material that does not release gas, such as plating a soft metal.
  • the inner rotor functioning as a magnetic coupling has been described as using a permanent magnet and a back yoke
  • the material and shape of the permanent magnet and the back yoke are not limited to this.
  • the number of poles may not be the same as that of the rotor, or may not be the same.
  • a salient pole that does not use a permanent magnet may be used.
  • a resolver is used as an angle detector
  • it can be appropriately changed depending on manufacturing cost and resolution, and for example, an optical rotary encoder may be used.
  • the material, shape, and manufacturing method of the structural parts and partition walls arranged in and out of the other partition walls are appropriately changed depending on the manufacturing cost, the environment used, the load conditions, the configuration, and the like.
  • the present invention has been described above with reference to the embodiment. However, the present invention should not be construed as being limited to the above embodiment, and can be appropriately changed or improved.
  • 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.
  • reactive gas for etching may be introduced into the vacuum chamber after evacuation, but in the direct drive motor of this embodiment, the inside and outside are shielded by the partition walls. Therefore, there is no possibility that the motor coil or the insulating material will be etched.
  • FIG. 28 shows the present embodiment. It is a perspective view of a frog redder arm type conveying apparatus using a motor system composed of a powerful direct drive motor.
  • two direct drive motors Dl and D2 are connected in series.
  • a first arm A1 is connected to the rotor of the lower direct drive motor D1, and a first link L1 is pivotally connected to the tip of the first arm A1.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed.
  • a wafer transfer arm placed in a vacuum chamber in a semiconductor manufacturing apparatus for example, a device having a plurality of arms such as a scalar type or a frog redder type shown in the figure, particularly requires a plurality of rotary motors. It becomes.
  • the contact surface area with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc. should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good. Therefore, it is suitable for a direct drive motor that drives a robot apparatus without using a speed reducer as in the present invention.
  • the direct drive motor having a thin and large diameter and narrow width as in the present invention is used. Is preferred.
  • FIG. 29 is a view of the configuration of FIG. 28 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the internal structure of the two-axis motor system will be described in detail.
  • the direct drive motor D1 will be described.
  • a hollow cylindrical main body 12 joined coaxially to the central opening 10a of the disk 10 installed on the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition wall 13 attached to the upper end thereof.
  • the center of the main body 12 can be used for wiring to the stator.
  • the main body 12 and the disk 10 constitute a housing.
  • the partition wall 13 is made of stainless steel, which is a non-magnetic material, and extends from the peripheral edge of the wall portion 13a fitted in the main body 12 to the direct drive motors Dl and D2 in the axial direction. It consists of a thin cylindrical portion 13b. Accordingly, the partition wall 13 is commonly used for the direct drive motors Dl and D2.
  • the lower end of the cylindrical portion 13b is joined to a holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 with bolts 16.
  • TIG welding a holder 15
  • the contact surface between the holder 15 and the disk 10 is grooved so that the seal member is inserted into the groove. After the seal member OR is inserted into the groove, the holder 15 and the disk 10 are tightened with the bolt 16. Is the part on the atmosphere side Are isolated from each other.
  • the partition wall 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance, and is less magnetic.
  • the holder 15 is also made of SU S316 because of its weldability with the partition wall 13.
  • the partition wall 13 and the holder 15 are airtightly joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are hermetically sealed by O-rings OR, respectively. Therefore, the internal space surrounded by the disk 10 and the partition wall 13 is also hermetically sealed.
  • the partition wall 13 is not necessarily made of a nonmagnetic material. Further, instead of using an O-ring OR, the members may be hermetically sealed by electron beam welding or laser beam welding.
  • a bearing holder 17 is formed on the outer peripheral upper surface of the disc 10 in a body-like manner.
  • the bearing holder 17 is fitted with an outer ring of a four-point contact ball bearing 19 used in a vacuum and fixed by a bolt 20.
  • the inner ring of the bearing 19 is fixed to a double cylindrical cylindrical member 23 fitted with the first outer rotor member 21 and fixed by a bolt 22 that fastens the first outer rotor member 21 together.
  • the first outer rotor member 21 is rotatably supported with respect to the partition wall 13 by the cylindrical member 23 that supports the arm A1 (FIG. 28).
  • the first outer rotor member 21 and the cylindrical member 23 constitute an outer rotor.
  • the disc 10 (including the bearing holder 17) is made of austenitic stainless steel having high corrosion resistance.
  • the disc 10 also serves as a fitting and fixing device with the surface plate G, which is a chamber, and a sealing device.
  • a groove 10b for inserting the O-ring OR is provided on the lower surface thereof.
  • Bearing 19 is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing for the direct drive motor D1 is required, so the two-axis coaxial motor system of the present invention can be made thinner.
  • the bearing 19 is made of martensite stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so as not to release outgas even in vacuum, or a four-point contact ball. Because it is a bearing, the force that can receive the moment in the direction of tilting of the first outer rotor member 21 from the arm A1 A bearing can also be used, and it may be used in a preloaded state, or fluorine film treatment (DFO) may be performed to improve lubricity.
  • DFO fluorine film treatment
  • the cylindrical member 23 has a surface for fitting and fixing the inner ring of the bearing 19.
  • the four-point contact ball bearing 19 is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 which is a rotating ring is tightly fitted or intermediately fitted to the cylindrical member 23 which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring of the bearing 19, which is a fixed ring, is fitted to the austenitic stainless steel bearing holder or aluminum holder 17 so that the friction torque due to a decrease in the rotational accuracy of the bearing 19 or a rise in temperature is reduced. It is configured to prevent the rise.
  • the first outer rotor member 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material to form a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is made up of a wedge (not shown) that also has power.
  • Permanent magnet 21a has a configuration of 32 poles, each of which has 16 poles of N poles and S poles, each of which is a magnetic metal cage, and is divided into segments, each of which has a fan shape. .
  • Permanent magnet 21a is a high energy product, neodymium (Nd-Fe-B) based magnet, which is nickel-coated to enhance corrosion resistance.
  • the yoke 21b is made of low-carbon steel with high magnetism, and is nickel-plated to improve wear resistance and corrosion resistance after machining and to prevent wear during bearing replacement.
  • the first stator 29 is disposed so as to face the inner peripheral surface of the first outer rotor member 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12, and is formed of a laminated material of electromagnetic steel plates. After the bobbin is fitted, the motor coil is concentrated.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a first inner rotor 30 is disposed adjacent to and parallel to the first stator 29.
  • the first inner rotor 30 is rotatably supported by ball bearings 33 with respect to a resolver holder 32 bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock 30b.
  • the permanent magnet 30a has a 32-pole configuration, and each of 16 N-pole and S-pole magnets alternately has a magnetic metal force. Accordingly, the first inner rotor 30 is rotated in synchronism with the first outer rotor member 21 driven by the first stator 29.
  • the bearing 33 that rotatably supports the first inner rotor 30 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D1 because only one bearing is required. Since the interior of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a is bonded and fixed to the back yoke 30b.
  • Permanent magnet 30a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 30b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a and 34b are assembled as detectors for measuring the rotation angle on the inner periphery of the first inner rotor 30, and the resolver stator 35 is disposed on the outer periphery of the resolver holder 32 so as to face the rotor rotors 34a and 34b.
  • the high-resolution incremental resolver stator 35 and the absolute resolver stator 36 that can detect the position of the rotor in one rotation are arranged in two layers. /!
  • the resolver holder 32 and the first inner rotor 30 are magnetic so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35 and 36, which are angle detectors.
  • the body is made of carbon steel and is chromate-plated to prevent fouling after processing and molding.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Are provided with teeth shifted in phase with respect to the incremental resolver rotor 34a at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the incremental resolver rotor 34a rotates together with the first inner rotor 30, the reluctance between the incremental resolver stator 35 and the magnetic pole changes, and the fundamental wave component of the change in reluctance is n cycles in one revolution of the incremental resolver rotor 34a.
  • the change in reluctance is detected, digitalized by the resolver control circuit shown in FIG. 30 and used as a position signal, so that the rotational angle of the incremental resolver rotor 34a, that is, the first inner rotor 30 is (Or rotation speed) is detected.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor member 21, that is, the first outer rotor member 21 rotates.
  • the resolver alone has the bearing 33 without using any part of the motor that forms the motor. Therefore, the eccentricity of the resolver alone can be adjusted before the resolver coil is assembled into the housing. Since accuracy adjustment such as position adjustment can be performed, it is not necessary to provide adjustment holes and notches on both flanges of the housing.
  • the main body 12 constitutes a housing.
  • the above-described cylindrical member 23 of the direct drive motor D1 extends upward to a position where it overlaps with the direct drive motor D2, and has a four-point contact ball bearing 19 ′ used in vacuum on its inner peripheral surface.
  • the outer ring is fitted and fitted with bolts 20 '.
  • the inner ring of the bearing 19 ′ is fixed by a bolt 22 ′ that fits around the circumferential surface of the double cylindrical ring-shaped member 23 ′ and fastens the second outer rotor member 21 ′ together.
  • the second outer rotor member 21 ′ is a ring-shaped member 23 ′ that supports the arm A2 (FIG. 28). Thus, it is rotatably supported with respect to the partition wall 13.
  • the second outer rotor member 21 ′ and the ring-shaped member 23 ′ constitute an outer rotor.
  • Bearing 19 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing. Therefore, the force that can receive the moment in the tilting direction of the first outer rotor member 21 from the arm A1 is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. It can be used in the state, or fluorine coating (DFO) can be applied to improve lubricity.
  • DFO fluorine coating
  • the ring-shaped member 23 ' has a surface for fitting and fixing the inner ring of the bearing 19'.
  • the four-point contact ball bearing 19 ' is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in the accuracy of the assembled parts and the linear expansion coefficient. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′ has an interference fit or an intermediate fit on the yoke 21b which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring is fitted with an austenitic stainless steel bearing holder or aluminum boss to prevent a decrease in rotational accuracy of the bearing 19 'and an increase in friction torque due to temperature rise.
  • the second outer rotor member 21 ' mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is composed of a wedge (not shown) that also has non-magnetic force.
  • Permanent magnet 21a ' is a segment type with a configuration of 32 poles, each consisting of 16 magnets of N poles and S poles alternately made of magnetic metal and divided into poles, each of which has a sector shape.
  • the inner and outer diameter arc centers are the same, but the tangent intersection of the circumferential end face is closer to the permanent magnet 21a ', so that the wedge 2 lb 'The permanent magnet 21a' is fastened to the yoke 21b 'by tightening with a screw from the outer diameter side.
  • 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 with a high energy product, and has a nickel coating to improve corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel, which has high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance after machining and to prevent wear during bearing replacement.
  • the second stator 29 ' is disposed so as to face the inner peripheral surface of the second outer rotor member 21'.
  • the second stator 29 ′ is attached to the upper part of the flange 12 a that extends in the radial direction in the center of the main body 12, and is formed of a laminated material of electromagnetic steel sheets, and each salient pole is insulated. After the bobbin is fitted, the motor coil is concentrated.
  • the outer diameter of the second stator 29 ′ is substantially the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is disposed adjacent to and parallel to the second stator 29'.
  • the second inner rotor 30 ′ is rotatably supported by a ball bearing 33 ′ with respect to a resolver holder 32 ′ that is bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a knock yoke 30b ′.
  • the permanent magnet 30a ′ has a configuration of 32 poles, like the permanent magnet 21a ′ of the second outer rotor member 21 ′, and 16 magnets of N poles and S poles are alternately made of magnetic metal. Accordingly, the second inner rotor 30 ′ is driven to rotate in synchronization with the second outer rotor member 21 ′ by the second stateer 29 ′.
  • the bearing 33 'that rotatably supports the first inner rotor 30' is a four-point contact ball bearing that can carry radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing is required, so the direct drive motor D2 can be made thinner. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a ′ Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a ′ is fixed to the back yoke 30b ′.
  • Permanent magnet 30a ' is a high energy product neodymium (Nd-Fe-B) magnet It has a nickel coating to prevent demagnetization due to wrinkles.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a 'and 34b' are assembled on the inner circumference of the second inner rotor 30 'as detectors for measuring the rotation angle, and the outer circumference of the resolver holder 32' is opposed to it.
  • the resolution of the resolver stator 35 ', 36' is high resolution incremental resolver stator 35, and the absolute resolver stator 36 'that can detect the position of the rotor in one rotation.
  • the rotational angle of the absolute resolver rotor 34b ' is known, no return to origin is required, and the electrical phase angle of the magnet with respect to the coil is different. This is possible without using a pole detection sensor.
  • the resolver holder 32 'and the second inner rotor 30' are magnetic bodies so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 'and 36' which are angle detectors. Carbon steel is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor member 21 ′. Can be detected through the partition wall 13.
  • the resolver alone has the bearing 33 ′ without using the parts forming the motor, and therefore the eccentricity adjustment with the resolver alone is not performed before the housing is assembled. Because it is possible to adjust the accuracy of the housing position, etc., it is not necessary to provide a separate adjustment hole or notch on both flanges of the housing.
  • the incremental resolver rotor 34a ′ has a plurality of slot tooth rows having a constant pitch, and the outer circumference of the incremental resolver stator 35.
  • the surface is provided with teeth that are shifted in phase with respect to the incremental resolver rotor 34a 'at each magnetic pole in parallel with the rotation axis, and a coil is wound around each magnetic pole.
  • Incremental resolver port integrated with second inner rotor 30 ' When the motor 34a rotates, the reluctance with the magnetic pole of the incremental resolver stator 35 changes, and the fundamental wave component of the change in reluctance becomes n cycles in one rotation of the incremental resolver rotor 34a.
  • the rotational angle (or rotational speed) of the incremental resolver rotor 34a ' Is detected.
  • the resolver rotors 34a, 34b and the resolver stators 35, 36 constitute a detector.
  • the outer rotor of the direct drive motor D2 (the second outer rotor 21 and the ring-like member 23), the outer rotor of the other direct drive motor D1 (the first outer rotor 21 and The cylindrical member 23) is supported by the bearing 19 ', so if the outer rotor of the direct drive motor D2 is removed, the powerful outer rotor can be supported! If the outer rotor of the direct drive motor D1 is removed, the bearing 19 supporting the powerful outer rotor can be exposed, and these can be easily inspected and removed, thus improving maintainability. Furthermore, since only the outer rotor outside the partition wall 13 has to be removed, a leak check or the like is not required at the time of reassembly without the need to remove the partition wall structure, thereby improving the assemblability.
  • the first stator 29 and the second stator 29 ' are vertically arranged around the flange portion 12a, and the resolver is arranged radially inward thereof.
  • the main body 12 has a hollow structure, and the flange portion 12a has at least one radial through hole 12d communicating with the center through which the motor wiring is drawn out to the center of the main body 12. It has a structure.
  • at least one notch 12e, 12e is provided at each end of the main body 12, and the resolver wiring is drawn out to the center of the main body 12 through these.
  • the angle of the stator and resolver can be adjusted. Therefore, if a separate facility for rotationally driving the reference outer rotor is prepared, the angle of the resolver relative to the stator can be adjusted with high accuracy by setting the main body 12 incorporating the stator and resolver in the facility. Can reduce the accuracy of angular positioning due to misalignment. In addition, the compatibility of the drive control circuit with the biaxial coaxial motor of the present invention can be improved.
  • FIG. 31 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • the drive signal is output, and the drive current is supplied to the direct drive motors Dl and D2 with a three-layer amplifier (AMP) force.
  • AMP three-layer amplifier
  • the absolute resolver stators 36 and 36 ' that detect the absolute position of one rotation of the rotating shaft and the incremental resolver stators 35 and 35' that detect the rotational position with finer resolution are used in this embodiment. Since the variable reluctance resolver is used, the rotational position control of the outer rotor members 21 and 21, that is, the arms Al and A2, can be performed with high accuracy.
  • FIG. 32 is a cross-sectional view similar to FIG. 29 that is helpful for the second embodiment.
  • FIG. 29 different parts from the embodiment of FIGS. The parts having functions are denoted by the same reference numerals and the description thereof is omitted.
  • an annular portion 113a is bolted in an airtight manner via an O-ring OR to a step portion 11Oa of the upper disc portion 110 attached to the upper surface of the cylindrical main body 112. ing.
  • the lower portion of the annular portion 113a is a thin flange portion 113c extending radially outward, and the upper end of the thin cylindrical portion 113b is TIG welded to the bent outer edge.
  • the thickness of the attachment portion of the annular portion 113a is thicker than the thickness of the flange portion 113c and the thin cylindrical portion 113b.
  • the lower end of the thin cylindrical portion 113b is TIG welded to the holder 15 in the same manner as in the above-described embodiment.
  • the annular portion 113a, the flange portion 113c, the thin cylindrical portion 113b, and the holder 15 constitute a partition wall 113.
  • the disc portion 110, the main body 112, and the disc 10 constitute a nosing.
  • the upper surface of the upper disc portion 110 is closed by the lid member 101, and the bearing holder 107 attached to the outer periphery thereof 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 disk part 110, the lid member 101, and the bearing holder 107 have high corrosion resistance and are made of austenitic stainless steel.
  • the outer diameter portion 110a of the mounting seat surface of the bearing holder 107 in the upper disc portion 110 is located radially inward from the thin cylindrical portion 113b. Therefore, if the bearing holder 107 is removed from the upper disc portion 110, 2
  • the two outer rotor members 21 and 21 ′ can be removed upward without disassembling the upper disk portion 110. Therefore, it is possible to facilitate work that does not require disassembly of the airtight structure during maintenance. That is, the maximum outer diameter portion of the housing (main body 12 and upper disc portion 110) supporting the partition wall structure is the outer rotor of the direct drive motors D1 and D2 (the outer rotor members 21 and 21 ′ and the ring-shaped member 23).
  • the outer rotor of the direct drive motors D1 and D2 can be removed from the bulkhead 13 by removing the bearing holder 107 from the housing, which facilitates inspection and removal. , Maintenance is also improved. Furthermore, since only the bearing holder 107 need be removed, there is no need to check for leaks when reassembling without the need to remove the bulkhead structure, and assemblability is improved.
  • a flange is formed against the thickness of the annular portion 113a of the partition wall 113. Since the thickness of the portion 113c is thin, the thin flange portion 113c is deformed even when axial expansion and contraction stress occurs in the partition wall 113 due to dimensional accuracy, mechanical accuracy, and temperature change. In addition, axial stress and bending stress of the partition wall 113 can be relieved, thereby preventing a seal failure or breakage. Further, since it is not necessary to process the annular portion 113a and the upper disk portion 110 and the main body 12 to which the annular portion 113a is attached with high accuracy, a lower cost direct drive motor can be provided.
  • the force described using the example using the surface magnet type 32-pole 36-slot outer rotor brushless motor is not limited to this type of motor.
  • any brushless motor can be used, and other magnetic pole types such as a permanent magnet embedded type, other slot combinations, or an inner rotor type may be used.
  • a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles and 36 slots
  • the second axis is 24 poles and 27 slots
  • the first axis and the third axis are 32 poles and 3 6 slots. If the two axes and the fourth axis are configured with 24 poles and 27 slots, mutual interference such as generation of thrust in the rotational direction to the rotor and magnetic coupling device due to the magnetic field of each axis can be prevented.
  • the rotor permanent magnet is a neodymium (Nd-Fe-B) -based magnet, and nickel coating is used as an example for coating to improve corrosion resistance.
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high-temperature demagnetization depending on the temperature conditions during beta-out.
  • System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the yoke is made of low carbon steel and explained with an example of nickel plating.
  • This material is not limited to the surface treatment, and is appropriately changed depending on the environment used. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method of fastening the permanent magnet to the yoke has been described using an example in which the non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw. May be bonded or other fastening methods.
  • bearings 19 and 19 have been described using an example of grease grease lubrication for four-point contact ball bearings. However, this is not limited to this type, material, and lubrication method. It can be changed as appropriate depending on conditions, rotational speed, etc., and it can be a cross roller bearing. In the case of a 4-axis coaxial motor, it can be supported by another bearing to further increase mechanical rigidity. If a multi-point contact bearing cannot be used, such as when rotating at high speeds, a bearing that supports the rotor of each shaft and another bearing may be configured to apply preload as deep groove ball bearings or angular bearings. When used in an ultra-vacuum, it is possible to use a metal-lubricated material that does not emit gas, such as a metal ring plated with a soft metal such as gold or silver.
  • the inner rotor functioning as a magnetic coupling has been described as using a permanent magnet and a back yoke.
  • the material and shape of the permanent magnet and the back yoke are not limited thereto.
  • the number of poles may not be the same as that of the rotor, or may not be the same.
  • a salient pole that does not use a permanent magnet may be used.
  • a resolver is used as an angle detector
  • it can be appropriately changed depending on manufacturing cost and resolution, and for example, an optical rotary encoder may be used.
  • the material, shape, and manufacturing method of the structural parts and partition walls arranged in and out of the other partition walls are appropriately changed depending on the manufacturing cost, the environment used, the load conditions, the configuration, and the like.
  • the present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above embodiment. Of course, it should be understood that modifications and improvements can be made as appropriate, which should not be construed as limited to the above.
  • the motor system of the present embodiment can be used not only in a vacuum atmosphere but also in an atmosphere outside the atmosphere.
  • a reactive gas for etching may be introduced into the vacuum chamber after evacuation.
  • the inside and the outside are shielded by the partition walls. Also, there is no risk of the motor coil or insulation material being etched.
  • FIG. 33 is a perspective view of a frog redder arm type transport device using a direct drive motor that works in the present embodiment.
  • four direct drive motors Dl, 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.
  • 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.
  • first arm A1 is connected to the rotor of the upper direct drive motor D3, and a first link L1 'is pivotally connected to the tip of the first arm A1.
  • second arm A2 is connected to the rotor of the uppermost direct drive motor D4, and the second link L2 ′ is pivotally connected to the tip of the second arm A2.
  • the links LI and L2 are pivotally connected to the table T on which the wafer W is placed, and the links Ll 'and L2' are pivoted to the table T 'on which another wafer W is placed. It is linked movably.
  • the table T also rotates in the same direction. It approaches or separates from motors Dl and D2. Therefore, if the direct drive motors Dl and D2 are rotated at an arbitrary angle, the wafer W can be transferred to an arbitrary two-dimensional position within a range where the table T can reach.
  • the table T ' also rotates in the same direction, and if the powerful rotor rotates in the opposite direction, the table T' becomes a direct drive motor. It approaches or separates from D3 and D4. Therefore, If the direct drive motors D3 and D4 are rotated at an arbitrary angle, the wafer W can be transferred to an arbitrary two-dimensional position within the range that the table T ′ can reach.
  • a plurality of rotations are particularly required.
  • a motor is required.
  • the contact surface area with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc. should be minimized to make effective use of space.
  • This embodiment uses a surface magnet type 32-pole 36-slot outer rotor brushless direct drive motor.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good.
  • the direct drive motor that drives a robot apparatus without using a speed reducer as in the present invention. is there.
  • the direct drive motor having a thin and large diameter and narrow width as in the present invention is used. Is preferred.
  • FIG. 34 is a diagram of the configuration of FIG. 33 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the hollow cylindrical first main bodies 12 are fixed to each other by bolts 11 fitted into the central opening 10a of the disc 10 installed on the surface plate G.
  • the first body 12 has a reduced diameter portion 12h on the outer periphery of its upper end.
  • the second main body 112 having a shape similar to that of the first main body 12 has a large-diameter portion 112h on the inner periphery of the lower end thereof.
  • the first main body 12 and the second main body 112 are connected coaxially.
  • the center of the main bodies 12 and 112 can be used to pass wiring to the stator.
  • the first main body 12, the disc 10 and the second main body 112 constitute a housing.
  • a disc member 110 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 disc member 110 is bolted to the lower surface of the upper end of the partition wall 13 and has a bearing holder 107 attached to the outer periphery.
  • 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 non-magnetic material, and passes through the direct-drive motors D4, D3, D2, and D1 in the axial direction from the periphery of the thick disk portion 13a attached to the disk member 110. And a thin cylindrical portion 13b extending. 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 wall 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 with bolts 16.
  • the contact surface between the holder 15 and the disk 10 is provided with a groove force to fit the seal member. After the seal member OR is fitted into the groove, the holder 15 and the disk 10 are fastened by the bolt 16. , Atmospheric side force is also separated from the fastening part.
  • Bulkhead 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance and is particularly low in magnetism.
  • the holder 15 is also made of SUS316 because of its weldability with the partition wall 13.
  • the disk member 110 and the partition wall 13, and the partition wall 13 and the holder 15 are hermetically joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are respectively O- Airtight by ring OR. Therefore, the external force of the internal space surrounded by the disk 10, the disk member 110, and the partition wall 13 is also airtight.
  • the partition wall 13 is not necessarily made of a nonmagnetic material. Further, instead of using an O-ring OR to seal the air, the members may be sealed by electron beam welding or laser beam welding.
  • the bearing holder 17 On the outer peripheral upper surface of the disc 10, the bearing holder 17 is formed in a body-like manner. An outer ring of a four-point contact ball bearing 19 used in a vacuum is fitted to the bearing holder 17 in a fitting manner and fixed with bolts 20. On the other hand, the inner ring of the bearing 19 is fixed to a double cylindrical cylindrical member 23 including the first outer rotor member 21 and is fixed by a bolt 22 that fastens the first outer rotor member 21 together. Yes. That is, the first outer rotor member 21 is rotatably supported with respect to the partition wall 13 by the cylindrical member 23 that supports the arm A1 (FIG. 33).
  • the first outer rotor member 21 and the cylindrical member 23 constitute an outer rotor.
  • the disc 10 and the bearing holder 17 are made of austenitic stainless steel, which has high corrosion resistance.
  • the disc 10 also serves as a fitting and fixing device with the surface plate G that is a chamber, and a lower surface thereof.
  • a groove 10b is provided to fill the O-ring OR.
  • Bearing 19 is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing.
  • the direct drive motor D1 requires only one bearing, so the four-axis coaxial motor system of the present invention can be made thinner.
  • the bearing 19 is made of martensite stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so as not to release outgas even in vacuum, or a four-point contact ball. Since this is a bearing, the moment in the direction in which the first outer rotor member 21 tilts from the arm A1 is Force that can be received Not only the four-point contact type, but also cross rollers, cross balls, and cross taper bearings can be used, and they can be used in a preload state, or fluorine film treatment (DFO) to improve lubricity You can go!
  • DFO fluorine film treatment
  • the first outer rotor member 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material to form a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It is made up of a wedge (not shown) that also has power.
  • Permanent magnet 21a has a configuration of 32 poles, each of which has 16 poles of N poles and S poles, each of which is a magnetic metal cage, and is divided into segments, each of which has a fan shape. .
  • Permanent magnet 21a is a high energy product, neodymium (Nd-Fe-B) based magnet, which is nickel-coated to enhance corrosion resistance.
  • the yoke 21b is made of low-carbon steel with high magnetism, and is nickel-plated to improve wear resistance and corrosion resistance after machining and to prevent wear during bearing replacement.
  • a first stator 29 is arranged on the radially inner side of the partition wall 13 so as to face the inner peripheral surface of the first outer rotor member 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12, and is formed of a laminated material of electromagnetic steel plates. After the bobbin is fitted, the motor coil is concentrated.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • the first inner rotor 30 is disposed adjacent to and parallel to the first stator 29.
  • the first inner rotor 30 is rotatably supported by ball bearings 33 with respect to a resolver holder 32 bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock 30b.
  • the permanent magnet 30a has a 32-pole configuration, and each of the 16 N-pole and S-pole magnets alternately has a magnetic metal force. Accordingly, the first inner rotor 30 is rotated in synchronism with the first outer rotor member 21 driven by the first stator 29.
  • the bearing 33 that rotatably supports the first inner rotor 30 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the direct drive motor D1 can be made thinner because only one bearing is required. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a is bonded and fixed to the back yoke 30b.
  • Permanent magnet 30a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 30b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a and 34b are assembled on the inner periphery of the first inner rotor 30 as detectors for measuring the rotation angle, and the resolver stator 35 is disposed on the outer periphery of the resolver holder 32 so as to face it.
  • the high-resolution incremental resolver stator 35 and the absolute resolver stator 36 that can detect the position of the rotor in one rotation are arranged in two layers. /!
  • the resolver holder 32 and the first inner rotor 30 are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35, 36 that are angle detectors. In order to prevent fouling after processing and molding, it is chromated.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Are provided with teeth shifted in phase with respect to the incremental resolver rotor 34a at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • Incremental resolver rotor integrated with first inner rotor 30 34 When a rotates, the reluctance with the magnetic pole of the incremental resolver stator 35 changes, and the fundamental wave component of the reluctance change becomes n periods in one rotation of the incremental resolver rotor 34a, and the change in the reluctance is detected.
  • the resolver control circuit shown in FIG. 35 shows an example in which the resolver control circuit shown in FIG. 35 is used as a position signal to detect the rotation angle (or rotation speed) of the incremental resorno rotor 34a, that is, the first inner rotor 30. Yes.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor member 21, that is, the first outer rotor member 21 rotates.
  • the resolver alone has the bearing 33 without using any part of the motor that forms the motor. Therefore, the eccentricity of the resolver alone can be adjusted before the resolver coil is assembled into the housing. Since accuracy adjustment such as position adjustment can be performed, it is not necessary to provide adjustment holes and notches on both flanges of the housing.
  • the first main body 12 constitutes housing.
  • the cylindrical member 23 of the direct drive motor D1 described above extends upward to a position where it overlaps with the direct drive motor D2, and the four-point contact ball bearing used in the vacuum on the inner peripheral surface 19
  • the outer ring of ' is fitted in and fitted with bolts 20'.
  • the inner ring of the bearing 19 ' is fixed by a bolt 22' that fits around the circumferential surface of a double cylindrical ring-shaped member 23 'and fastens the second outer rotor member 21' together.
  • the second outer rotor member 21 ′ is rotatably supported with respect to the partition wall 13 by the ring-shaped member 23 ′ that supports the arm A2 (FIG. 33).
  • the second outer rotor member 21 ′ and the ring-shaped member 23 ′ constitute an outer rotor.
  • Bearing 19 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the direct drive motor D2 requires only one bearing, so the four-axis coaxial motor of the present invention can be made thinner.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even in vacuum. ing.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing. Therefore, the force that can receive the moment in the tilting direction of the second outer rotor member 21 from the arm A1 is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. It can be used in the state, or fluorine coating (DFO) can be applied to improve lubricity.
  • DFO fluorine coating
  • the ring-shaped member 23 ' has a surface for fitting and fixing the inner ring of the bearing 19'.
  • the four-point contact ball bearing 19 ' is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in the accuracy of the assembled parts and the linear expansion coefficient. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′, which is a rotating ring, is tightly fitted or intermediately fitted to a ring-shaped member 23 ′ that is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as that of the bearing ring material.
  • the second outer rotor member 21 ' mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is made up of a wedge (not shown) that also has non-magnetic strength.
  • Permanent magnet 21a ' is a segment type with a configuration of 32 poles, each consisting of 16 magnets of N poles and S poles alternately made of magnetic metal and divided into poles, each of which has a sector shape.
  • the inner and outer diameter arc centers are the same, but the tangential intersection of the circumferential end face is closer to the permanent magnet 21a ', so that the wedge is tightened from the outer diameter side of the yoke 2 lb' by tightening the screw with the permanent magnet 21a.
  • the permanent magnet 21a ' is a neodymium (Nd-Fe-B) magnet with a high energy product, and has a nickel coating to improve corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel with high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after machining.
  • the second stator 29 ' is disposed so as to face the inner peripheral surface of the second outer rotor member 21'.
  • the second stator 29 ′ is attached to a cylindrically deformed upper portion of the flange portion 12 a extending in the radial direction at the center of the first main body 12, and is formed of a laminated material of electromagnetic steel plates, and is attached to each salient pole. In this case, the motor coil is concentrated after the bobbin is fitted as an insulation treatment.
  • the outer diameter of the second stator 29 is substantially the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is arranged on the radially inner side of the second stator 29'.
  • the second inner rotor 30 ′ is rotatably supported by a ball bearing 33 ′ with respect to a resolver holder 32 ′ bolted to the outer peripheral surface of the first main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a back yoke 30b ′.
  • the permanent magnet 30a ′ has a configuration of 32 poles, like the permanent magnet 21a ′ of the second outer rotor member 21 ′, and is composed of 16 magnetic poles of N poles and S poles alternately made of magnetic metal. Accordingly, 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 'that rotatably supports the second inner rotor 30' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing is required, so the direct drive motor D2 can be made thinner. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • the permanent magnet 30a ′ Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a ′ is bonded and fixed to the back yoke 30b ′.
  • the permanent magnet 30a ' is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • a resolver rotor 34b ' is assembled on the inner circumference of the second inner rotor 30' as a detector for measuring the rotation angle.
  • the resolver stator 32 ' is arranged on the outer circumference of the resolver holder 32' so as to face it. In this embodiment, it is possible to detect the high-resolution incremental resolver stator 35 and the position of the rotor in one rotation.
  • the absolute resolver stator 36 ' is arranged in two layers.
  • the resolver holder 32 'and the second inner rotor 30' are magnetic bodies so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 'and 36' which are angle detectors. Carbon steel is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor member 21 ′. Can be detected through the partition wall 13.
  • the resolver alone has the bearing 33 ′ without using the parts forming the motor, and therefore the eccentricity adjustment with the resolver alone is not performed before the housing is assembled. Because it is possible to adjust the accuracy of the housing position, etc., it is not necessary to provide a separate adjustment hole or notch on both flanges of the housing.
  • the incremental resolver rotor 34a ′ has a plurality of slot tooth rows having a constant pitch, and the outer circumference of the incremental resolver stator 35.
  • the surface is provided with teeth that are shifted in phase with respect to the incremental resolver rotor 34a ′ at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the reluctance change is detected so that it becomes n cycles, digitalized by the resolver control circuit shown in Fig. 35, and used as a position signal, so that the incremental resolver rotor 34a ', that is, the first inner
  • the rotation angle (or rotation speed) of the rotor 30 is detected.
  • the resolver rotors 34a, 34b and the resolver stators 35, 36 constitute a detector.
  • a resolver is arranged on the radially inner side.
  • the first body 12 has a hollow structure, and the flange portion 12a has at least one radial through hole 12d communicating with the center, through which the motor wiring is routed.
  • the structure is drawn out to the center of
  • at least one notch 12e, 12e is provided at each end of the first main body 12, and the resolver wiring is drawn out to the center of the first main body 12 through these notches.
  • the housing side force can also be arranged in the order of the direct motor D 1 resolver, the stator 29, the direct motor D2 stator 29, and the resolver in this order, making it easy to use two axes.
  • the angle of the stator and resolver can be adjusted. Therefore, if a facility for rotating the reference outer rotor is prepared separately, the angle of the resolver relative to the stator can be adjusted with high accuracy by setting the first main body 12 incorporating the stator and resolver in the facility. Therefore, it is possible to prevent the angle positioning accuracy from being lowered due to the deviation of the commutation, and to improve the compatibility of the drive control circuit with the four-axis coaxial motor of the present invention.
  • FIG. 36 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • the drive signal is output, and the drive current is supplied to the direct drive motors Dl and D2 with a three-layer amplifier (AMP) force.
  • AMP three-layer amplifier
  • the resolver signal is output from the resolver stators 35, 36, 35', 36 'that detected the rotation angle as described above.
  • the CPU input after digital conversion at (RDC) determines whether or not the outer rotor member 21, 21 'has reached the command position, and if it reaches the command position, the drive signal to the 3-layer amplifier (AMP) To stop the rotation of the outer rotor members 21, 21 '.
  • AMP 3-layer amplifier
  • the absolute resolver stators 36 and 36 ' that detect the absolute position of one rotation of the rotating shaft and the incremental resolver stators 35 and 35 that detect the rotational position with finer resolution are used in this embodiment. Since the variable reluctance resolver consisting of 'is used, the rotational position control of the outer rotor members 21 and 21, that is, the arms Al and A2, can be performed with high accuracy.
  • a force detector that employs a resolver for detecting the rotation of the inner rotor 30 can be arranged on the atmosphere side inside the partition wall 13, so that a servo motor generally used for high-precision positioning is highly accurate and smooth.
  • 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.
  • the direct drive motor D4 will be described.
  • the outer ring of the four-point contact ball bearing 119 that is used in the vacuum is fitted into the bearing holder 107 that is bolted to the disc member 110 attached to the second body 112 so as to be detachable. It is attached and fixed with bolts 120.
  • the inner ring of the bearing 119 is fixed by a bolt 122 that is fitted into a double cylindrical cylindrical member 123 including the first outer rotor member 121 and is fastened together with the first outer rotor member 121. . That is, the first outer rotor member 121 is rotatably supported with respect to the partition wall 113 by the cylindrical member 123 that supports the arm A2 ′ (FIG. 33).
  • the first outer rotor member 121 and the cylindrical member 123 constitute an outer rotor.
  • the bearing holder 107 has high corrosion resistance and is made of austenitic stainless steel.
  • Bearing 119 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing of the direct drive motor D4 is required, so the four-axis coaxial motor system of the present invention can be made thinner.
  • Bearing 119 is made of martensitic stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 119 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so that no outgassing occurs even in a vacuum, or a four-point contact ball. Since this is a bearing, the moment in the direction in which arm A2, the first outer rotor member 121 of the force is tilted Force that can be received Not only the four-point contact type, but also cross rollers, cross balls, and cross taper bearings can be used, and they can be used in a preload state, or fluorine film treatment (DFO) to improve lubricity You can go!
  • DFO fluorine film treatment
  • the first outer rotor member 121 is composed of a permanent magnet 121a, an annular yoke 121b made of a magnetic material to form a magnetic path, and a nonmagnetic material for mechanically fastening the permanent magnet 121a and the yoke 121b. It is composed of a wedge (not shown) that also has physical strength.
  • the permanent magnet 121a is a segment type in which each of the N poles and S poles has a configuration of 32 poles, each consisting of 16 magnetic poles, each of which is divided into poles, each of which has a fan shape.
  • the inner and outer diameter arc centers are the same, but the tangent intersection of the circumferential end face is closer to the permanent magnet 121a, so that the wedge is tightened with a screw from the outer diameter side of the yoke 121b, and the permanent magnet 121a is yoked. It is signed to 121b.
  • the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • the permanent magnet 121a is a neodymium (Nd—Fe-B) magnet with a high energy product, and is nickel-coated to enhance corrosion resistance.
  • the yoke 12 lb is made of low-carbon steel with high magnetic properties, and is plated with nickel to improve wear resistance and corrosion resistance after machining and to prevent wear during bearing replacement.
  • a first stator 129 is disposed on the inner side in the radial direction of the partition wall 113 so as to face the inner peripheral surface of the first outer rotor member 121.
  • the first stator 129 is attached to a cylindrically deformed lower portion of a flange portion 112a extending in the radial direction at the center of the main body 112.
  • the first stator 129 is formed of a laminated material of electromagnetic steel plates, and each salient pole is insulated. After the bobbin is fitted, the motor coil is concentrated.
  • the outer diameter of the first stator 129 is substantially 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 ball bearings 133 with respect to a resolver holder 132 that is bolted to the outer peripheral surface of the second main body 112.
  • a permanent magnet 130a is attached to the outer peripheral surface of the first inner rotor 130 via a knock yoke 130b.
  • the permanent magnet 130a has a configuration of 32 poles as in the case of the permanent magnet 121a of the first outer rotor member 121, and 16 magnets of N poles and S poles alternately have a magnetic metal force. Therefore, the first inner rotor 130 is The first outer rotor member 121 driven by the first stator 129 is rotated in synchronization.
  • the bearing 133 that rotatably supports the first inner rotor 130 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing is required, so the direct drive motor D4 can be made thinner. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 130a is bonded and fixed to the back yoke 130b.
  • Permanent magnet 130a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 130b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 134a and 134b are assembled as detectors for measuring the rotation angle on the inner periphery of the first inner rotor 130, and the resolver stator 135 is disposed on the outer periphery of the resolver holder 132 so as to face the rotor.
  • a high-resolution incremental resolver stator 135 and an absolute resolver stator 136 capable of detecting whether the rotor is in one rotation are arranged in two layers.
  • the resolver holder 132 and the first inner rotor 130 are made of carbon steel, which is a magnetic body, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 135 and 136 that are angle detectors. As a material, it is chromate-plated to prevent fouling after processing and molding.
  • the high-resolution variable reluctance resolver used in this embodiment has an incremental resolver rotor 134a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 135. Includes magnetic poles parallel to the axis of rotation. Teeth that are out of phase with the resolver rotor 134a are provided, and a coil is wound around each magnetic pole.
  • the incremental resolver port 134a rotates integrally with the first inner rotor 130, the reluctance between the magnetic poles of the incremental resolver stator 135 changes, and the fundamental wave component of the reluctance change is changed by one rotation of the incremental resolver rotor 134a.
  • Incremental resolver rotor 134a that is, first inner rotor 130 is detected by detecting the change in reluctance so that there are n cycles, digitalizing it by the resolver control circuit shown in FIG. 35 and using it as a position signal. Rotation angle (or rotation speed) is detected.
  • the detector is composed of the Resonore rotors 134a and 134b and the Resonore stators 135 and 136.
  • the first inner rotor 130 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor member 121, that is, rotates with the first outer rotor member 121.
  • the rotation angle can be detected through the partition wall 13.
  • the parts forming the motor have the bearing 133 as a single resolver without using the nosing, so the eccentricity adjustment with the resolver alone can be performed before the resolver is assembled. Since accuracy adjustment such as position adjustment can be performed, it is not necessary to provide a separate adjustment hole or notch on both flanges of the housing.
  • the second main body 112 constitutes a housing.
  • the cylindrical member 123 of the direct drive motor D4 described above extends downward to a position where it overlaps with the direct drive motor D3, and the inner peripheral surface of the four-point contact ball bearing 119 ′ used in vacuum is used.
  • the outer ring is fitted and fixed by bolt 120 '.
  • the inner ring of the bearing 119 ′ is fixed by a bolt 122 ′ that fits around the circumferential surface of the double cylindrical ring-shaped member 123 ′ and fastens the second outer rotor member 121 ′ together. That is, the second outer rotor member 121 ′ is rotatably supported with respect to the partition wall 13 by the ring-shaped member 123 ′ that supports the arm A 1 ′ (FIG. 33).
  • the second outer rotor member 121 ′ and the ring-shaped member 123 ′ constitute an outer rotor.
  • Bearing 119 ' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing for the direct drive motor D3 is required, so the four-axis coaxial motor of the present invention can be made thinner.
  • Both inner and outer rings are corrosion resistant Made of martensitic stainless steel, which has high properties and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 119 ' is a four-point contact ball bearing that can be made by using a metal lubrication that does not emit outgas even in a vacuum by plating a soft metal such as gold or silver on the inner and outer rings. Therefore, the force that can receive the moment in the tilting direction of the arm A1 and the second outer rotor member 121 ′ of force is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. It can be used in a pre-loaded state, or fluorine-based film treatment (DFO) can be performed to improve lubricity.
  • DFO fluorine-based film treatment
  • the second outer rotor member 121 mechanically fastens the permanent magnet 121a', the annular yoke 121b 'made of a magnetic material to form a magnetic path, and the permanent magnet 121a' and the yoke 121b '. It is made up of a wedge (not shown) that also has a non-magnetic force.
  • Permanent magnet 121a ' is a segment type with 32 poles and 16 N pole and S pole magnets, each of which is divided into magnetic poles, each of which has a sector shape. is there.
  • the inner and outer diameter arc centers are the same, but the tangential intersection of the circumferential end face is closer to the permanent magnet 121a ', so that the wedge is tightened with a screw from the outer diameter side of the yoke 121b'.
  • 121a ' is fastened to yoke 1 21b'.
  • the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • Permanent magnet 121a ' is a neodymium (Nd-Fe-B) magnet with high energy accumulation, and has a nickel coating to enhance corrosion resistance.
  • Yoke 121b ' is made of low-carbon steel with high magnetism, and after molding, it is plated with nickel to improve fouling and corrosion resistance and prevent wear during bearing replacement.
  • the second stator 129 ' is disposed so as to face the inner peripheral surface of the second outer rotor member 121'.
  • the second stator 129 ′ is attached to the cylindrically deformed upper portion of the flange portion 112a that extends in the radial direction at the center of the second main body 112, and is formed of a laminated material of electromagnetic steel sheets. After the bobbin is fitted into the salient pole as an insulation treatment, the motor coil is concentrated.
  • the outer diameter of the second stator 129 ' is approximately the same as or smaller than the inner diameter of the partition wall 13!
  • a second inner rotor 130 ' is disposed on the radially inner side of the second stator 129'.
  • the second inner rotor 130 ′ is rotatably supported by a ball bearing 133 ′ with respect to a resolver holder 132 ′ bolted to the outer peripheral surface of the second main body 112.
  • a permanent magnet 130a ' is attached to the outer peripheral surface of the second inner rotor 130' via a knock yoke 130b '! /.
  • the permanent magnet 130a ′ has a configuration of 32 poles as in the case of the permanent magnet 121a ′ of the second outer rotor member 121 ′, and 16 magnets of N poles and S poles are alternately made of magnetic metal. Accordingly, the second inner rotor 130 'is driven to rotate in synchronization with the second outer rotor member 121' by the second stator 129 '! / Speak.
  • the bearing 33 'that rotatably supports the second inner rotor 30' is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D3 because only one bearing is required. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • the permanent magnet 130a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 130a 'is fixedly bonded to the back yoke 130b'.
  • the permanent magnet 130a is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 130b ' is made of low-carbon steel with high magnetism and is chromate-plated for protection after machining.
  • resolver rotors 134a, 134b are assembled as detectors for measuring the rotation angle, and on the outer periphery of the resolver holder 132, facing each other.
  • the resolver stators 135 'and 136' are attached to a high-resolution incremental resolver stator 135, and an absolute resolver stator 136 'that can detect the position of the rotor in one rotation. Arranged in two layers.
  • the resolver holder 132 and the second inner rotor 130 do not transmit the electromagnetic noise of the motor field and the motor coil force to the resolver stators 135 'and 136' which are angle detectors.
  • carbon steel which is a magnetic material, is used as a material, and chromate plating is applied to prevent fouling after processing and molding.
  • the second inner rotor 130 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor member 121 ′.
  • the rotation angle can be detected through the partition wall 13.
  • the resolver alone has the bearing 133 ′ without using the parts forming the motor, and therefore the eccentricity adjustment of the resolver alone before the assembly into the housing is performed. Since accuracy adjustment such as position adjustment can be performed, there is no need to provide adjustment holes or notches on both flanges of the housing.
  • the incremental resolver rotor 134a ′ has a plurality of slot teeth having a constant pitch, and the magnetic poles of the incremental resolver stator 135.
  • teeth whose phases are shifted with respect to the incremental resolver rotor 134a ′ at each magnetic pole in parallel with the rotation axis are provided, and a coil is wound around each magnetic pole.
  • Incremental resolver rotor 134a that is, the second inner side is detected by detecting the change in reluctance so that the wave component has n cycles, digitizing it by the resolver control circuit shown in FIG. 35 and using it as a position signal.
  • the rotation angle (or rotation speed) of the rotor 130 ' is detected.
  • the resolver rotors 134a and 134b and the resolver stators 135 and 136 constitute a detector.
  • the second body 112 has a hollow structure, and the flange portion 112a has at least one radial through hole 112d communicating with the center, through which the motor wiring is connected to the second wire 112d. It is structured to be pulled out to the center of the main body 112.
  • at least one notch 112e, 112e force is provided at both ends of the second main body 112, and the resolver wiring is drawn out to the center of the second main body 112 via these.
  • Direct motor D4 resorno, stator 129, direct motor D3 stator 129, and resolver can be arranged in this order, and the angle between the stator and resolver can be adjusted easily even though it is two axes. Therefore, if a separate facility for rotationally driving the reference outer rotor is prepared, the angle of the resolver with respect to the stator can be adjusted with high accuracy by setting the second body 112 incorporating the stator and resolver into the facility. Therefore, it is possible to prevent the angle positioning accuracy from being lowered due to the deviation of the com- mission, and to improve the compatibility of the drive control circuit with the four-axis coaxial motor of the present invention.
  • FIG. 36 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • Drive signal is output, and drive current is supplied to the three-layer amplifier (AMP) force direct drive motors D3 and D4.
  • AMP three-layer amplifier
  • the resolver signal is output from the resolver stator 135, 136, 135', 136 'whose rotation angle is detected as described above.
  • the CPU input after digital conversion at) determines whether or not the outer rotor member 121, 121 'has reached the command position, and if it reaches the command position, stops the drive signal to the 3-layer amplifier (AMP) As a result, the rotation of the outer rotor members 121 and 121 ′ is stopped. As a result, servo control of the outer rotor members 121 and 121 ′ becomes possible.
  • arm A1' When driving multiple axes in a vacuum environment, if the current rotation position of arms A1 and A2 'is not recognized when the power is turned on, arm A1'
  • the absolute resolver stators 136 and 136 that detect the absolute position of one rotation of the rotating shaft, and the incremental resolver stator that detects a rotational position with finer resolution are used in this embodiment. Since the variable reluctance resolver consisting of 135 and 135 is employed, the rotational position control of the outer rotor members 121 and 121, that is, the arms Al and A 2 'can be performed with high accuracy.
  • the detector is a partition wall. Since the servo motor generally used for high-accuracy positioning uses an optical encoder or magnetoresistive element that is used as a position detection means for smooth driving with high accuracy. A magnetic type encoder can be used.
  • the cylindrical member 123 that constitutes the outer rotor of the (first) direct drive motor D4 closest to the upper end of the motor system that works in this embodiment is detachably attached to the housing (here, the cylindrical member 110).
  • the outer diameter portion 110a of the mounting seat surface of the bearing holder 107 in the cylindrical member 110 is positioned in the radial direction from the thin cylindrical portion 13b. .
  • the bearing holder 107 if the bearing holder 107 is removed, the cylindrical member 123 of the direct drive motor D4 and the cylindrical member 123 of the direct drive motor D3 supported by the bearing 119 ′ are connected to the outer rotor members 121 and 121 ′.
  • the direct drive motors D2 and D1 can be withdrawn from the bulkhead 13 in an integrated manner, so that inspection and removal can be easily performed, thereby improving maintainability.
  • a leak check or the like is not required at the time of reassembly without the need to remove the partition wall structure, and assemblability is improved.
  • the first main body 12 and the second main body 112 are connectable in an arbitrary phase in the axial direction, that is, two adjacent direct drive motors Dl, D2, and D3 , Removably bolted to each unit used in D4.
  • the first main body 12 includes, in order from the disk 10, the angle detector of the direct drive motor D1, the stator of the direct drive motor D1, the stator of the direct drive motor D2, and the angle of the direct drive motor D2.
  • the first main body 12 side force is also in order, the direct drive motor D3 axis angle detector, direct drive motor D3 axis stator, direct drive motor D4 stator
  • the angle detectors of the direct drive motor D4 can be arranged in this order, and the angle of the angle detector with respect to the stator can be easily adjusted for each axis. Therefore, if a facility for rotating the reference motor rotor is prepared separately, the first main body or the second main body incorporating the motor stator and the rotation detector can be set in that equipment, so that the individual In addition, the angle of the angle detector with respect to the motor stator can be adjusted with high accuracy.
  • the surface magnet type can be improved. 32 poles 36 slots outer rotor type brushless motor explained with an example using motors Not limited to this type of motor
  • Any brushless motor can be used, and other magnetic pole types such as a permanent magnet embedded type, other slot combinations, or an inner rotor type may be used.
  • a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles, 36 slots
  • the second axis is 24 poles, 27 slots
  • the first axis and the third axis are 32 poles, 36 slots
  • the rotor permanent magnet is a neodymium (Nd-Fe-B) -based magnet, and nickel coating is used as an example of coating to improve corrosion resistance.
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high temperature demagnetization depending on the temperature conditions during beta-out System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the yoke is made of low-carbon steel and explained with an example of nickel plating.
  • This material is not limited to the surface treatment, and is appropriately changed depending on the environment used. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method for fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw, but it may be changed as appropriate depending on the environment in which it is used. May be bonded or other fastening methods.
  • bearings 19, 19 ', 119, 119' are examples using 4-point contact ball bearings with grease lubrication for vacuum
  • the structure may be supported by another bearing to further increase the mechanical rigidity, or when a multipoint contact bearing cannot be used, such as when rotating at high speed
  • a bearing that supports the rotor and another bearing may be preloaded as a deep groove ball bearing or an anguilla bearing, and when used in ultra-vacuum, a soft metal such as gold or silver is used for the bearing ring.
  • metal lubrication that does not emit gas, such as
  • the inner rotor functioning as a magnetic coupling has been described as using a permanent magnet and a back yoke.
  • the material and shape of the permanent magnet and the back yoke are not limited thereto.
  • the number of poles may not be the same as that of the outer rotor, or the width may not be the same.
  • a salient pole that does not use a permanent magnet is also acceptable.
  • a resolver is used as an angle detector
  • it can be appropriately changed depending on manufacturing cost and resolution, and for example, an optical rotary encoder may be used.
  • the magnetic force coupling used in each rotor and rotation detector generates a thrust in the rotational direction by the magnetic flux leaking the magnetic coupling force used in the rotor, stator, and resolver of each axis.
  • magnetic shields for shielding each other's magnetic fields are arranged between the rotors of the respective shafts, and the rotor, stator, and resolver force of each shaft are generated.
  • a magnetic shield is provided to shield each other's electromagnetic field so that the generated electromagnetic field does not interfere with each other's resolver, or the number of poles of the rotor between adjacent shafts in the axial direction.
  • a multi-axis coaxial motor system such as 4-axis coaxial or 4-axis coaxial can be configured with a reduced overall axial length.
  • a multi-axis direct drive motor such as a 4-axis coaxial system
  • two frog redder arm robots that can be positioned with high accuracy without greatly changing the chamber structure can be installed. Performance and availability can be increased. Needless to say, it can also be used for motor systems with four or more axes.
  • 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.
  • reactive gas for etching may be introduced into the vacuum chamber after evacuation, but in the direct drive motor of this embodiment, the inside and outside are shielded by the partition walls. Therefore, there is no possibility that the motor coil or the insulating material will be etched.
  • FIG. 37 is a perspective view of a frog redder arm type transfer device using a direct drive motor that works in this embodiment.
  • two direct drive motors Dl 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 pivotally connected to the tip of the first arm A1.
  • 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 tip of the second arm A2.
  • the links LI and L2 are pivotally connected to a table T on which Ueno and W are placed.
  • a wafer transfer arm placed in a vacuum chamber in a semiconductor manufacturing apparatus for example, an apparatus having a plurality of arms such as a scalar type or a frog redder type shown in the figure, particularly requires a plurality of rotary motors. It becomes.
  • the surface area of contact with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc., should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space.
  • a surface magnet type 32-pole 36-slot outer rotor brushless type direct drive motor is used.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good.
  • FIG. 38 is a diagram of the configuration of FIG. 37 cut along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the internal structure of the two-axis motor system will be described in detail with reference to FIG. First, the direct drive motor D1 will be described.
  • a hollow cylindrical main body 12 fitted in the central opening 10a of the disk 10 installed on the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition wall 13 attached to the upper end thereof.
  • the center of the main body 12 can be used to pass wiring to the stator.
  • the main body 12 and the disk 10 constitute a housing.
  • the partition wall 13 is made of stainless steel, which is a non-magnetic material, and extends from the peripheral edge of the partition wall 13 to the main body 12 so as to penetrate the direct drive motors Dl and D2 in the axial direction. It consists of an existing thin cylindrical portion 13 b and a holder 15. Therefore, the partition wall 13 is commonly used for the direct drive motors Dl and D2.
  • the lower end of the cylindrical portion 13b is joined to a holder 15 so as to be sealed by TIG welding, and the holder 15 is fixed to the disc 10 with bolts 16.
  • the contact surface between the holder 15 and the disc 10 is provided with a groove force that fits the seal member. After the seal member OR is fitted into the groove, the holder 15 and the disc 10 are fastened by the bolt 16. As a result, the fastening part is isolated from the atmospheric force.
  • the partition wall 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance, and is particularly magnetic.
  • the holder 15 is also made of SUS316 because of its weldability with the partition wall 13.
  • the partition wall 13 and the holder 15 are hermetically joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are hermetically sealed by O-rings OR, respectively. Therefore, the internal space surrounded by the disk 10 and the partition wall 13 is also hermetically sealed.
  • the partition wall 13 is not necessarily made of a nonmagnetic material. Further, instead of using an O-ring OR, the members may be hermetically sealed by electron beam welding or laser beam welding.
  • Bearing holder 1 which is a separate member from the upper surface of the outer periphery of the disk 10 which is an atmospheric outer member 1 7 is fixed by bolts 18.
  • the bolt 18 is disposed outside the cylindrical member 23 and exposes its head.
  • An outer ring of a four-point contact ball bearing (first bearing) 19 used in a vacuum is fitted to the bearing holder 17 in a fitting manner, and is fixed by a bolt 20 via an annular bearing restraint BH.
  • the inner ring of the bearing 19 is fitted to the outer periphery of the first outer rotor 21 and is fixed by a bolt 22 via an annular bearing restraint BH.
  • the first outer rotor 21 is rotatably supported by the bearing 19 and the partition wall 13 by the bearing 19, and a cylindrical member 23 that supports the arm A1 (FIG. 37) is formed on the upper surface thereof. It is fixed by 24.
  • the bolt 24 can fasten a magnetic shield plate 25 (indicated by a dotted line) extending radially inward to the cylindrical member 23 together.
  • the first outer port 21 and the cylindrical member 23 constitute an outer rotor.
  • 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 fixing device with the surface plate G, which is a chamber, on the lower surface thereof.
  • a groove 10b is provided to fill the O-ring OR.
  • the magnetic shield plate 25 is subjected to nickel plating in order to enhance the anti-corrosion and corrosion resistance after press-forming the SPCC steel plate, which is a magnetic material.
  • the effect of the bearing 19, which will be described later, is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing for the direct drive motor D1 is required, so the two-axis coaxial motor system of the present invention can be made thinner.
  • the bearing 19 is made of martensite stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so as not to release outgas even in vacuum, or a four-point contact ball. Because it is a bearing, it can receive a moment in the direction in which the first outer rotor 21 tilts from the arm A1, but it is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. Yes, it can be used under preload conditions, or fluorine film treatment (DFO) can be performed to improve lubricity! ⁇ .
  • DFO fluorine film treatment
  • the first outer rotor 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material to form a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It consists of a wedge (not shown).
  • Permanent magnet 21a has a configuration of 32 poles, each of which has 16 poles of N poles and S poles alternately made of magnetic metal, and is divided into segments. Each of the permanent magnets 21a has a sector shape.
  • the permanent magnet 21a is a neodymium (Nd—Fe—B) based magnet having a high energy product, and has a nickel coating to enhance corrosion resistance.
  • the yoke 21b is made of a low-carbon steel having high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the first outer rotor 21 has a surface for fitting and fixing the inner ring of the bearing 19 and the cylindrical member 23.
  • the four-point contact ball bearing 19 is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 which is a rotating ring is an interference fit or an intermediate fit to the yoke 21b which is easy to obtain processing accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring of the bearing 19, which is a fixed ring, is fitted to the austenitic stainless steel bearing holder or aluminum boss to prevent the bearing 19 from rotating and the friction torque from increasing due to temperature rise. ing.
  • the first stator 29 is disposed so as to face the inner peripheral surface of the first outer rotor 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12.
  • the first stator 29 is formed of a laminated material of electromagnetic steel plates and is insulated from each salient pole. As a process, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • the first inner rotor 30 is disposed on the radially inner side of the first stator 29.
  • the first inner rotor 30 has a ball shaft with respect to the resolver holder 32 bolted to the outer peripheral surface of the main body 12. It is rotatably supported by a receiver 33.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock 30b.
  • the permanent magnet 30a is composed of 32 poles in the same manner as the permanent magnet 21a of the first outer rotor 21, and 16 magnets of N poles and S poles are alternately made of magnetic metal. Accordingly, the first inner rotor 30 is rotated in synchronism with the first outer rotor 21 driven by the first stator 29.
  • the bearing 33 that rotatably supports the first inner rotor 30 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D1 because only one bearing is required. Since the interior of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a is bonded and fixed to the back yoke 30b.
  • Permanent magnet 30a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 30b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a and 34b are assembled as detectors for measuring the rotation angle on the inner periphery of the first inner rotor 30, and the resolver stator 35 is disposed on the outer periphery of the resolver holder 32 so as to face it.
  • the high-resolution incremental resolver stator 35 and the absolute resolver stator 36 that can detect the position of the rotor in one rotation are arranged in two layers. /!
  • the resolver holder 32 and the first inner rotor 30 are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35, 36 that are angle detectors. In order to prevent fouling after processing and molding, chromate plating is applied.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Are provided with teeth shifted in phase with respect to the incremental resolver rotor 34a at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the reluctance between the incremental resolver stator 35 and the magnetic pole changes, and the fundamental wave component of the change in reluctance is n cycles in one revolution of the incremental resolver rotor 34a.
  • the change in reluctance is detected, digitalized by the resolver control circuit shown in FIG. 39, and used as a position signal, so that the rotational angle of the incremental resolver rotor 34a, that is, the first inner rotor 30 is (Or rotation speed) is detected.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor 21, that is, rotates with the first outer rotor 21, so that the first outer rotor 21 rotates.
  • the corner can be detected through the bulkhead 13.
  • the resolver alone has the bearing 33 without using the parts forming the motor and the uzing, and therefore, the eccentricity adjustment with the resolver alone is performed before the resolver coil is assembled into the housing. Since accuracy adjustment such as position adjustment can be performed, there is no need to provide adjustment holes or notches on both flanges of the housing.
  • the rotating wheel of the bearing device 19 that is rotatably supported by the first outer rotor 21 is fitted into a rotor yoke 21b that is easy to obtain machining accuracy and has the same linear expansion coefficient as the driving wheel of the bearing device 19.
  • the rotation accuracy can be improved and the friction torque can be prevented from changing due to temperature changes.
  • the main body 12 constitutes a housing.
  • the above-described cylindrical member 23 of the direct drive motor D1 extends upward to a position where it overlaps with the direct drive motor D2, and has a four-point contact ball bearing (no. 2 bearing)
  • the outer ring of 19 ' is fitted in a fitting manner, and is fixed by a bolt 20' via an annular bearing restraint BH '.
  • the inner ring of the bearing 19 ' is fitted to the outer periphery of the second outer rotor 21, and is attached to the bolt 22 via the annular bearing restraint BH. It is more fixed.
  • the bolt 22 'and the magnetic shield plate 41 (indicated by a dotted line) extending radially inward can be fastened together.
  • the second outer rotor 21 ′ is rotatably supported by the bearing 19 ′ with respect to the cylindrical member 23 and the partition wall 13, and the ring-shaped member 23 ′ supporting the arm A 2 (FIG. 37) is It is fixed on the top surface with bolts 24 '.
  • the bolt 24 ' has a magnetic shield plate 25' extending radially inward and fastened together with the ring-shaped member 23 '.
  • the cylindrical member 23 ′ integrated with the second outer rotor 21 ′ covers the bolt 20 ′ with axial outward force and radial outward force.
  • the second outer rotor 21 ′ and the cylindrical member 23 ′ constitute an outer rotor.
  • the magnetic shield plates 41, 25 can be plated with nickel in order to increase the anti-corrosion and corrosion resistance after press molding the SPCC steel plate, which is a magnetic material.
  • the magnetic shield plates 4 1 and 25 are interposed between the first outer rotor 21 and the second outer rotor 21 to form a magnetic shield, and each other due to magnetic flux leakage from them! Has a function to prevent the bag from being carried around. That is, the magnetic shield plate 25 ′ can be fastened to the yoke 21b ′ with the ring-shaped member 23 ′, which is a nonmagnetic material, interposed therebetween, thereby preventing generation of an unnecessary magnetic circuit. Since the magnetic shield plates 41 and 25 can prevent magnetic interference between the rotors, the overall axial length can be reduced even though it is a two-axis coaxial motor system.
  • the magnetic shield plate 41 can prevent external force from attracting foreign matter.
  • Bearing 19 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing.
  • the first outer rotor 21 from the arm A1 can receive a moment in the tilting direction, but it is not limited to the four-point contact type, but a cross roller, a cross ball, and a cross taper shaft.
  • the second outer rotor 21 ' mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is made up of a wedge (not shown).
  • Permanent magnet 21a ' is a segment type with a configuration of 32 poles, with 16 N-pole and S-pole magnets alternately made of magnetic metal and divided into poles, each of which has a sector shape.
  • the center of the arc of the inner and outer diameters is the same force.By making the tangent intersection of the circumferential end face closer to the permanent magnet 21a ', the wedge is tightened from the outer diameter side of the yoke 21b' by screwing the permanent magnet 21a ' It is fastened to the yoke 21b '. With this configuration, the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • Permanent magnet 21a ' is a high energy product neodymium (Nd-Fe-B) based magnet, which is coated with nickel to enhance corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel with high magnetism and is plated with nickel in order to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the second outer rotor 21 ' has a surface for fitting and fixing 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 its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′ is tightly fitted or intermediately fitted to the yoke 21b, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring is made into a clearance fit with a bearing holder made of austenitic stainless steel or an aluminum boss, thereby preventing a decrease in rotational accuracy of the bearing 19 'and an increase in friction torque due to a temperature rise.
  • a second stator 29 ' is disposed so as to face the inner peripheral surface of the second outer rotor 21'.
  • the second stator 29 ' is attached to the upper part of the flange 12a that extends in the radial direction in the center of the main body 12, and is formed of a laminated material of electromagnetic steel sheets, and each salient pole is insulated. As shown, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the second stator 29 ' is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is arranged inside the second stator 29' in the radial direction.
  • the second inner rotor 30 ′ is rotatably supported by a ball bearing 33 ′ with respect to a resolver holder 32 ′ bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a back yoke 30b ′.
  • the permanent magnet 30a ' has a 32-pole configuration, like the permanent magnet 21a' of the second outer rotor 21 ', and has 16 magnetic poles each having N poles and S poles alternately. Accordingly, the second inner rotor 30 ′ is rotationally driven by the second stator 29 ′ in synchronization with the second outer rotor 21 ′.
  • the bearing 33 'that rotatably supports the first inner rotor 30' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing is required, so the direct drive motor D2 can be made thinner. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • the permanent magnet 30a ′ Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a ′ is bonded and fixed to the back yoke 30b ′.
  • the permanent magnet 30a ' is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • resolver rotors 34a' and 34b ' are assembled as detectors for measuring the rotation angle, and the outer periphery of the resolver holder 32' is opposed to the detector.
  • the resolution of the resolver stator 35 ', 36' is high resolution incremental resolver stator 35, and the absolute resolver stator 36 'that can detect the position of the rotor in one rotation.
  • the resolver holder 32 and the second inner rotor 30 are configured so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 'and 36' that are angle detectors.
  • Carbon steel, which is a magnetic material, is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor 21 ′, that is, rotates with the rotation angle of the second outer rotor 21 ′.
  • the parts forming the motor, the bearing 33 is provided as a single resolver without using uzing, and therefore, the eccentricity adjustment with the single resolver is performed before being incorporated into the housing. Since it is possible to adjust the accuracy of the resolver coil position, etc., there is no need to provide separate adjustment holes or cutouts on both flanges of the housing.
  • the rotating wheel of the bearing device 19 ′ that is rotatably supported by the second outer rotor 21 ′ is fitted to the rotor yoke 21 b ′, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the driving wheel of the bearing device 19 ′.
  • the incremental resolver rotor 34a ′ has a plurality of slot tooth rows having a constant pitch, and the outer circumference of the incremental resolver stator 35.
  • the surface is provided with teeth that are shifted in phase with respect to the incremental resolver rotor 34a ′ at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the reluctance change is detected so that the wave component has n cycles, is digitalized by the resolver control circuit shown in FIG. 39, and is used as a position signal, so that the incremental resolver rotor 34a ′, that is, the first 2The rotation angle (or rotation speed) of the inner rotor 30 'is detected.
  • the resolver rotors 34a, 34b and the resolver stators 35, 36 constitute a detector.
  • the magnetic shield plates 25, 41 are arranged between the first outer rotor 21 and the second outer rotor 21 'to suppress mutual magnetic interference. , Malfunctions such as erroneous driving and accompanying people can be avoided.
  • the outer peripheral edge 12b of the flange portion 12a extending between the direct drive motors Dl and D2 in the main body 12 is made of carbon steel, which is a magnetic material.
  • the first stator 29 and the second stator 29 ′ are interposed between the first stator 29 and the second stator 29 ′, and they are affected by the leakage magnetic flux, thereby generating a thrust in the wrong rotation direction on the first outer rotor 21 or the second outer rotor 21 ′.
  • it functions as a magnetic shield that shields each other's magnetic field.
  • the first stator 29 and the second stator 29 ' are vertically arranged around the flange portion 12a, and the resolver is arranged radially inside thereof.
  • the main body 12 has a hollow structure, and the flange portion 12a has at least one radial through hole 12d communicating with the center through which the motor wiring is drawn out to the center of the main body 12. It has a structure.
  • at least one notch 12e, 12e is provided at each end of the main body 12, and the resolver wiring is drawn out to the center of the main body 12 through these.
  • the angle of the stator and resolver can be adjusted. Therefore, if a separate facility for rotationally driving the reference outer rotor is prepared, the angle of the resolver relative to the stator can be adjusted with high accuracy by setting the main body 12 incorporating the stator and resolver in the facility. Therefore, it is possible to prevent the angle positioning accuracy from being lowered due to the deviation of the commutation, and to improve the compatibility of the drive control circuit with the two-axis coaxial motor of the present invention.
  • FIG. 40 is a block diagram showing a drive circuit of the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • the drive signal is output, and the drive current is supplied to the direct drive motors Dl and D2 with a three-layer amplifier (AMP) force.
  • AMP three-layer amplifier
  • the resolver signal is output from the resolver stator 35, 36, 35, 36, which has detected the rotation angle as described above.
  • the CPU input after digital conversion judges whether or not the outer rotor 21, 21 'has reached the command position, and when it reaches the command position, it stops the drive signal to the 3-layer amplifier (AMP). Outside mouth Stop rotation of data 21, 21 '. This enables servo control of the outer rotors 21, 21 '.
  • FIGS. 41 to 44 are cross-sectional views illustrating the disassembly process of the motor system according to the present embodiment
  • FIGS. 45 to 48 are perspective views illustrating the disassembly process of the motor system according to the present embodiment. It is a figure.
  • the cylindrical member 23' can be separated by removing the bolt 24 'from the yoke 21b' in FIG. At this time, since the bearing 19 'can be visually confirmed, its lubrication state and the like can be inspected.
  • the minimum inner diameter force 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 wall 13.
  • the yoke 21b of the direct drive motor D1 is attached to the disk 10 by the bolt 18 via the bearing holder 17, and further, the direct drive motor D1 is connected to the cylindrical member 23 of the direct drive motor D1 via the bearing 19 '. Since the yoke 21b 'of D2 is installed, the direct drive motor Dl and D2 can be separated from the disk 10 and the bulkhead 13 together with the bearing holder 17 by removing the bolt 18, and the airtight structure of the bulkhead 13 must be disassembled. hardly perform maintenance work on the direct drive motor D1
  • FIG. 49 is a cross-sectional view showing a four-axis coaxial motor system that works on a modification of the present embodiment.
  • two sets of direct drive motors Dl and D2 (total 4 1) Directly arranged force
  • the individual direct drive motors have the same configuration as shown in FIG.
  • a partition wall holder 113a is hermetically coupled to the upper disk 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 peripheral surface thereof.
  • the upper end of 113b is TIG welded.
  • the lower end of the thin-walled cylinder 113b is TIG welded to the holder 15 as in the above-described embodiment.
  • the partition wall holder 113a, the thin cylinder 113b and the holder 15 constitute a partition wall. This is commonly used for the four direct drive motors.
  • the upper surface of the disc part 110 is closed by the lid member 101, and a bearing holder 107 attached to the outer periphery thereof supports the bearing 19.
  • the disc portion 110, the lid member 101, and the bearing holder 107 are made of austenitic stainless steel having high corrosion resistance.
  • the main body 12, the disc 10, and the upper disc portion 110 constitute a housing.
  • a separate bearing holder 17 is fixed by bolts 18 on the outer peripheral upper surface of the disk 10 which is an 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 ′ with respect to the cylindrical member 23.
  • a bearing holder 107 is fixed by bolts 118 on the outer peripheral upper surface of the upper disk part 110 which is an atmospheric outer member.
  • the first outer rotor 21 is supported by the bearing 19 with respect to the bearing holder 17.
  • the second outer port 21 ′ is supported by the bearing 19 ′ with respect to 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 wall 13, and the upper disk part 110 is separated.
  • the mounting outer peripheral surface of the bearing holder 107 is located on the inner side in the radial direction from the thin cylinder 113b.
  • the upper disk part 110 can be extracted upward without disassembling, and if the bearing holder 17 is further removed from the disk 10, the lower two outer rotors 21, 21 ' Can be extracted upward without disassembling. Therefore, when performing maintenance such as inspection and replacement of the bearing, the airtight structure using the partition wall 13 Maintenance work that does not require disassembly can be facilitated.
  • the magnetic shield plates 25 'and 25' are arranged between the second outer rotors 21 and 21 at the center, so that mutual magnetic interference is suppressed. This avoids malfunctions such as erroneous driving and companionship.
  • a magnetic shield plate 125 whose outer peripheral force extends in the radial direction to the inside of the thin cylinder 113b is disposed.
  • the magnetic 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 adjacent second outer rotor 21 ′ is affected by the leakage magnetic flux.
  • FIG. 50 is a perspective view of a frog-leg-game transport apparatus using a four-axis coaxial motor system that is effective in the present embodiment.
  • the first arm A1 is connected to the port of each direct drive motor D1, and the first link L1 is pivotally connected to the tip of the first arm A1.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed. Each table T moves independently.
  • the force described using the example using the surface magnet type 32-pole 36-slot outer rotor brushless motor is not limited to this type of motor.
  • any brushless motor can be applied, and other magnetic pole types such as a permanent magnet embedded type, other slot combinations, or an inner rotor type may be used.
  • a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles and 36 slots
  • the second axis is 24 poles and 27 slots
  • the first and third axes are 32 poles and 3 6 slots.
  • the two axes and the fourth axis are configured to have 24 poles and 27 slots, mutual interference such as generation of thrust in the rotational direction to the rotor and magnetic coupling device due to the magnetic field of each axis can be prevented.
  • the neodymium (Nd-Fe-B) magnet was used as the permanent magnet of the rotor, and an example in which nickel coating was applied as a coating for enhancing corrosion resistance was described.
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high-temperature demagnetization depending on the temperature conditions during beta-out.
  • System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the yoke is made of low-carbon steel and explained with an example of nickel plating.
  • This material is not limited to the surface treatment, and is appropriately changed depending on the environment used. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method for fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw, but it may be changed as appropriate depending on the environment in which it is used. May be bonded or other fastening methods.
  • bearings 19 and 19 have been described using an example of grease grease lubrication for four-point contact ball bearings.
  • this is not limited to this type, material, and lubrication method. It can be changed as appropriate depending on conditions, rotational speed, etc., and it can be a cross roller bearing. In the case of a 4-axis coaxial motor, it can be supported by another bearing to further increase mechanical rigidity.
  • a bearing that supports the rotor of each shaft and another bearing may be configured to apply preload as deep groove ball bearings or angular bearings.
  • a metal-lubricated material that does not emit gas, such as a metal ring plated with a soft metal such as gold or silver.
  • the inner rotor functioning as the magnetic coupling has been described as a form using a permanent magnet and a back yoke
  • the material and shape of the permanent magnet and the back yoke are not limited to this.
  • the number of poles may not be the same as that of the outer rotor, or the width may not be the same.
  • a salient pole that does not use a permanent magnet is also acceptable.
  • the angle detector is appropriately changed depending on the manufacturing cost and resolution, and for example, an optical rotary encoder may be used.
  • the material, shape, and manufacturing method of the structural parts and partition walls arranged in and out of the other partition walls are appropriately changed depending on the manufacturing cost, the environment used, the load conditions, the configuration, and the like.
  • the thrust in the rotational direction is applied to the magnetic force coupling used for each rotor and rotation detector by the magnetic flux that leaks the magnetic coupling force used for the rotor, stator, and resolver of each axis.
  • magnetic shields for shielding each other's magnetic field are arranged between the rotors of each axis, or the electromagnetic fields generated by the rotor, stator and resolver force of each axis
  • a magnetic shield is provided to shield each other's electromagnetic field, or the number of rotor poles and the number of stator slots in the axially adjacent axes are changed.
  • 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.
  • a reactive gas for etching is introduced into the vacuum chamber.
  • the direct drive motor of this embodiment the interior and the exterior are shielded by the partition wall, so that the motor coil, insulating material, etc. There is also no risk of being etched.
  • FIG. 51 is a perspective view of a frog redder arm type transfer device using a direct drive motor that works in the present embodiment.
  • two direct drive motors Dl 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.
  • 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 LI and L2 are pivotally connected to a table T on which the wafer W is placed.
  • a wafer transfer arm placed in a vacuum chamber in a semiconductor manufacturing apparatus for example, a device having a plurality of arms such as a scalar type or a frog redder type shown in the figure, particularly requires a plurality of rotary motors. It becomes.
  • the contact surface area with the outside world should be minimized, and at the same time, the number of mounting holes for motors, etc. should be minimized to make effective use of space.
  • a plurality of direct drive motors Dl and D2 are connected coaxially at the housing part, and the connection part is tightly joined with a seal (tightly joined by welding, O-ring, metal gasket, etc.), and the motor rotor is arranged. It is necessary to separate the open space from the housing external space.
  • This embodiment uses a surface magnet type 32-pole 36-slot outer rotor brushless type direct drive motor.
  • the slot combination of 32 poles and 36 slots is generally known to have a large magnetic attraction force in the radial direction and large vibration during rotation. is there . 2 n times (n is an integer) cancels out the magnetic attractive force in the radial direction. Therefore, vibration during rotation can be achieved without increasing the roundness and coaxiality of the stator and rotor and the rigidity of the mechanical parts. Can be made small and cogging is inherently small, so that a very smooth rotation can be obtained.
  • the electrical angle cycle is greater than the mechanical angle cycle, so positioning controllability is good.
  • the direct drive motor that drives a robot apparatus without using a speed reducer as in the present invention.
  • the direct drive motor having a thin and large diameter and narrow width as in the present invention is used. Is preferred.
  • FIG. 52 is a view of the configuration of FIG. 51 taken along the ⁇ - ⁇ line and viewed in the direction of the arrow.
  • the internal structure of the two-axis motor system will be described in detail.
  • the direct drive motor D1 will be described.
  • a hollow cylindrical main body 12 fitted in the central opening 10a of the disk 10 installed on the surface plate G and fixed to each other by bolts 11 has a cup-shaped partition wall 13 attached to the upper end thereof.
  • the center of the main body 12 can be used to pass wiring to the stator.
  • the main body 12 and the disk 10 constitute a housing.
  • the partition wall 13 is made of stainless steel, which is a non-magnetic material.
  • the partition wall 13 extends from the peripheral edge of the partition wall 13 through the direct drive motors Dl and D2 in the axial direction. It consists of an existing thin cylindrical portion 13 b and a holder 15. Therefore, the partition wall 13 is commonly used for the direct drive motors Dl and D2.
  • the lower end of the cylindrical part 13b can be sealed by TIG welding
  • the holder 15 is fixed to the disk 10 with bolts 16.
  • the welded portions of the cylindrical portion 13b and the holder 15 to substantially the same thickness, it is possible to prevent heat from escaping only to the components on one side and to weld the fitting portions uniformly.
  • the contact surface between the holder 15 and the disc 10 is provided with a groove force that fits the seal member. After the seal member OR is fitted into the groove, the holder 15 and the disc 10 are fastened by the bolt 16. As a result, the fastening part is separated from the atmospheric force.
  • the partition wall 13 is made of austenitic stainless steel SUS316, which has high corrosion resistance, and is particularly magnetic.
  • the holder 15 is also made of SUS316 because of its weldability with the partition wall 13.
  • the partition wall 13 and the holder 15 are hermetically joined, and the holder 15 and the disk 10 and the disk 10 and the surface plate G are hermetically sealed by O-rings OR, respectively. Therefore, the internal space surrounded by the disk 10 and the partition wall 13 is also hermetically sealed.
  • the partition wall 13 is not necessarily made of a nonmagnetic material.
  • the members may be hermetically sealed by electron beam welding or laser beam welding.
  • a bearing holder 17 is fixed with bolts 18 on the outer peripheral upper surface of the disk 10.
  • the bearing holder 17 is fitted with an outer ring of a four-point contact ball bearing 19 that is used in a vacuum, and is fixed by bolts 20.
  • the inner ring of the bearing 19 is fitted to the outer periphery of the first outer rotor 21 and is fixed by bolts 22.
  • the first outer rotor 21 is rotatably supported with respect to the partition wall 13, and a cylindrical member 23 that supports the arm A 1 (FIG. 51) is fixed by the bolt 24.
  • the bolt 24 fastens the magnetic shield plate 25 extending inward in the radial direction together with 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 fixing device with the surface plate G that is a chamber, and a lower surface thereof.
  • a groove 10b is provided to fill the O-ring OR.
  • the magnetic shield plate 25 is subjected to nickel plating in order to improve the anti-corrosion and corrosion resistance after press forming the SPCC steel plate, which is a magnetic material.
  • the effect of the bearing 19, which will be described later, is a four-point contact ball bearing that can apply radial, axial, and moment loads with a single bearing.
  • the direct drive motor D1 Since only one bearing is required, the thickness of the biaxial coaxial motor system of the present invention can be reduced.
  • the bearing 19 is made of martensite stainless steel, which has high corrosion resistance for both the inner and outer rings and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even under vacuum.
  • the bearing 19 may be made of metal lubricated by plating a soft metal such as gold or silver on the inner ring and the outer ring so as not to release outgas even in vacuum, or a four-point contact ball. Because it is a bearing, it can receive a moment in the direction in which the first outer rotor 21 tilts from the arm A1, but it is not limited to the four-point contact type, and cross rollers, cross balls, and cross taper bearings can also be used. Yes, it can be used under preload conditions, or fluorine film treatment (DFO) can be performed to improve lubricity! ⁇ .
  • DFO fluorine film treatment
  • the first outer rotor 21 includes a permanent magnet 21a, an annular yoke 21b made of a magnetic material to form a magnetic path, and a non-magnetic material for mechanically fastening the permanent magnet 21a and the yoke 21b. It consists of a wedge (not shown).
  • Permanent magnet 21a has a configuration of 32 poles, each of which has 16 poles of N poles and S poles made of magnetic metal alternately, and is divided into segments. Each of the permanent magnets 21a has a sector shape.
  • the inner and outer diameter arc centers are the same, but the tangent intersection of the circumferential end face is closer to the permanent magnet 21a, so that the wedge is tightened from the outer diameter side of the yoke 21b by screwing the permanent magnet 21a to the yoke. Signed to 21b.
  • 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) based magnet having a high energy product, and is coated with nickel to enhance corrosion resistance.
  • the yoke 21b is made of a low-carbon steel having high magnetism, and is plated with nickel to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the first outer rotor 21 has a surface for fitting and fixing the inner ring of the bearing 19 and the cylindrical member 23.
  • the four-point contact ball bearing 19 is a very thin bearing, and its rotational accuracy and friction torque are greatly affected by differences in accuracy and linear expansion coefficient of the parts to be assembled. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 which is a rotating ring is an interference fit or an intermediate fit to the yoke 21b which is easy to obtain processing accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring of bearing 19, which is a fixed ring, is made of austenitic stainless steel bearing. By adopting a clearance fit between the holder and aluminum boss, the bearing 19 is prevented from lowering the rotational accuracy and preventing the friction torque from increasing due to temperature rise.
  • a first stator 29 is arranged on the inner side in the radial direction of the partition wall 13 so as to face the inner peripheral surface of the first outer rotor 21.
  • the first stator 29 is attached to a cylindrically deformed lower portion of a flange portion 12a extending in the radial direction at the center of the main body 12.
  • the first stator 29 is formed of a laminated material of electromagnetic steel plates and is insulated from each salient pole. As a process, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the first stator 29 is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • the first inner rotor 30 is disposed on the radially inner side of the first stator 29.
  • the first inner rotor 30 is rotatably supported by a ball bearing 33 with respect to a resolver holder 32 that is bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a is attached to the outer peripheral surface of the first inner rotor 30 via a knock 30b.
  • the permanent magnet 30a is composed of 32 poles in the same manner as the permanent magnet 21a of the first outer rotor 21, and 16 magnets of N poles and S poles are alternately made of magnetic metal. Accordingly, the first inner rotor 30 is rotated in synchronism with the first outer rotor 21 driven by the first stator 29.
  • the bearing 33 that rotatably supports the first inner rotor 30 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, it is possible to reduce the thickness of the direct drive motor D1 because only one bearing is required. Since the interior of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • Permanent magnet 30a Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a is bonded and fixed to the back yoke 30b.
  • Permanent magnet 30a is a high energy product neodymium (Nd-Fe-B) magnet with nickel coating to prevent demagnetization due to defects.
  • the yoke 30b is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • Resolver rotors 34a and 34b are assembled as detectors for measuring the rotation angle on the inner circumference of the first inner rotor 30, and the resolver stator 35 is disposed on the outer circumference of the resolver holder 32 so as to face the rotor rotors 34a and 34b.
  • a high resolution Arrange the resolver stator 35 and the absolute resolver stator 36 that can detect the position of the rotor in one rotation in two layers.
  • the resolver holder 32 and the first inner rotor 30 are made of carbon steel, which is a magnetic material, so that electromagnetic noise from the motor field and motor coil is not transmitted to the resolver stators 35, 36 that are angle detectors. In order to prevent fouling after processing and molding, it is chromated.
  • the high-resolution variable reluctance resolver used in the present embodiment has an incremental resolver rotor 34a having a plurality of slot teeth having a constant pitch, and the outer peripheral surface of the incremental resolver stator 35. Are provided with teeth shifted in phase with respect to the incremental resolver rotor 34a at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the incremental resolver rotor 34a rotates together with the first inner rotor 30, the reluctance between the incremental resolver stator 35 and the magnetic pole changes, and the fundamental wave component of the change in reluctance is n cycles in one revolution of the incremental resolver rotor 34a.
  • the change in reluctance is detected, digitized by the resolver control circuit shown in FIG. 53, and used as a position signal, so that the rotational angle of the incremental resolving rotor 34a, that is, the first inner rotor 30 is obtained. (Or rotation speed) is detected.
  • the resolver rotors 34a and 34b and the resolver stators 35 and 36 constitute a detector.
  • the first inner rotor 30 rotates at the same speed by the magnetic coupling action with respect to the first outer rotor 21, that is, rotates with the first outer rotor 21, so that the first outer rotor 21 rotates.
  • the corner can be detected through the bulkhead 13.
  • the resolver alone has the bearing 33 without using the parts forming the motor and the uzing, and therefore, the eccentricity adjustment with the resolver alone is performed before the resolver coil is assembled into the housing. Since the position adjustment and other precision adjustments can be made, the housing has holes for adjustment and cutouts on both flanges. There is no need to provide it separately.
  • the rotating wheel of the bearing device 19 that is rotatably supported by the first outer rotor 21 is fitted into a rotor yoke 21b that is easy to obtain machining accuracy and has the same linear expansion coefficient as the driving wheel of the bearing device 19. Therefore, it is possible to improve the rotational accuracy and prevent the friction torque from fluctuating due to temperature changes.
  • the main body 12 constitutes a housing.
  • the cylindrical member 23 of the direct drive motor D1 described above extends upward to a position where it is superimposed on the direct drive motor D2, and the inner peripheral surface thereof is a four-point contact ball bearing 19 'used in a vacuum.
  • the outer ring is fitted and fitted with bolts 20 '.
  • the inner ring of the bearing 19 ′ is fitted to the outer periphery of the second outer rotor 21 ′ and is fixed by the bolt 22 ′.
  • the bolt 22 'and the magnetic shield plate 41 extending inward in the radial direction are fastened together.
  • the second outer rotor 21 ′ is rotatably supported with respect to the partition wall 13, and a ring-shaped member 23 ′ that supports the arm A2 (FIG. 51) is fixed by a bolt 24 ′. Further, the bolt 24 'fastens the magnetic shield plate 25 extending inward in the radial direction together with the ring-shaped member 23'.
  • the magnetic shield plates 41 and 25 ' are subjected to nickel plating in order to enhance anti-corrosion and corrosion resistance after press molding the SPCC steel plate, which is a magnetic material.
  • the magnetic shield plates 41 and 25 are interposed between the first outer rotor 21 and the second outer rotor 21 to form a magnetic shield and prevent mutual rotation due to magnetic flux leakage from them. . That is, the magnetic shield plate 25 ′ is fastened to the yoke 21b ′ with the ring-shaped member 23 ′, which is a non-magnetic material, interposed therebetween, thereby preventing unnecessary magnetic circuits from being generated.
  • the magnetic shield plates 41 and 25 can prevent magnetic interference between the rotors, it is possible to achieve a configuration in which the overall shaft length is suppressed while being a biaxial coaxial motor system.
  • the magnetic shield plate 41 prevents foreign matter from being attracted from the outside.
  • Bearing 19 is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing.
  • the inner and outer rings are made of martensitic stainless steel, which has high corrosion resistance and can be hardened by quenching.
  • the rolling elements are ceramic balls, and the lubricant is vacuum grease that does not solidify even in vacuum. ing.
  • the bearing 19 ' may be made of a metal lubrication that is plated with a soft metal such as gold or silver on the inner ring and the outer ring and does not release outgas even in vacuum, or a four-point contact ball bearing.
  • a four-point contact type but also a cross roller, a cross ball, and a cross taper bearing can be used. It can be used under preload conditions, or it can be treated with fluorine coating (DFO) to improve lubricity! ⁇ .
  • DFO fluorine coating
  • the second outer rotor 21 mechanically fastens the permanent magnet 21a', the annular yoke 21b 'made of a magnetic material to form a magnetic path, and the permanent magnet 21a' and the yoke 21b '. It is made up of a wedge (not shown).
  • the permanent magnet 21a ' has a configuration of 32 poles, each of which has 16 poles of N poles and S poles made of magnetic metal, and is divided into poles, each of which has a sector shape.
  • the center of the arc of the inner and outer diameters is the same force.By making the tangent intersection of the circumferential end face closer to the permanent magnet 21a ', the wedge is tightened from the outer diameter side of the yoke 21b' by screwing the permanent magnet 21a ' It is fastened to the yoke 21b '. With such a configuration, the permanent magnet can be fastened without using a fixing member that generates outgas, such as an adhesive.
  • Permanent magnet 21a ' is a high energy product neodymium (Nd-Fe-B) based magnet, which is coated with nickel to enhance corrosion resistance.
  • Yoke 21b ' is made of low-carbon steel with high magnetism and is plated with nickel in order to improve wear resistance and corrosion resistance and prevent wear during bearing replacement after processing and molding.
  • the second outer rotor 21 ' has a surface for fitting and fixing 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 its rotational accuracy and friction torque are greatly affected by differences in the accuracy and linear expansion coefficient of the assembled parts. Therefore, in the case of the present embodiment, the inner ring of the bearing 19 ′ is tightly fitted or intermediately fitted to the yoke 21b, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the bearing ring material of the bearing.
  • the outer ring is made into a clearance fit with a bearing holder made of austenitic stainless steel or an aluminum boss, thereby preventing a decrease in rotational accuracy of the bearing 19 'and an increase in friction torque due to a temperature rise.
  • the second stator 29 ′ is arranged on the radially inner side of the partition wall 13 so as to face the inner peripheral surface of the second outer rotor 21 ' Then, the second stator 29 ′ is arranged.
  • the second stator 29 ′ is attached to the upper part of the flange 12 a that extends in the radial direction in the center of the main body 12, and is formed of a laminated material of electromagnetic steel sheets, and each salient pole is insulated. As shown, the motor coil is concentrated after the bobbin is fitted.
  • the outer diameter of the second stator 29 ′ is approximately the same as or smaller than the inner diameter of the partition wall 13.
  • a second inner rotor 30 ' is arranged on the radially inner side of the second stator 29'.
  • the second inner rotor 30 ′ is rotatably supported by a ball bearing 33 ′ with respect to a resolver holder 32 ′ bolted to the outer peripheral surface of the main body 12.
  • a permanent magnet 30a ′ is attached to the outer peripheral surface of the second inner rotor 30 ′ via a back yoke 30b ′.
  • the permanent magnet 30a ′ has a configuration of 32 poles, like the permanent magnet 21a ′ of the second outer rotor 21 ′, and has 16 magnetic poles each having N poles and S poles alternately. Accordingly, the second inner rotor 30 ′ is rotationally driven by the second stator 29 ′ in synchronization with the second outer rotor 21 ′.
  • the bearing 33 'that rotatably supports the first inner rotor 30' is a four-point contact ball bearing that can load radial, axial, and moment loads with a single bearing. By using this type of bearing, only one bearing is required, so the direct drive motor D2 can be made thinner. Since the inside of the partition wall 13 is an atmospheric environment, a bearing using grease lubrication based on general bearing steel and mineral oil can be applied.
  • the permanent magnet 30a ′ Since the inside of the partition wall 13 is an atmospheric environment, the permanent magnet 30a ′ is bonded and fixed to the back yoke 30b ′.
  • the permanent magnet 30a ' is a neodymium (Nd-Fe-B) magnet with a high energy product and is coated with nickel to prevent demagnetization due to defects.
  • Yoke 30b ' is made of low-carbon steel with high magnetism, and is chromated to prevent fouling after machining.
  • the resolver rotors 34a 'and 34b' are assembled as detectors for measuring the rotation angle on the inner periphery of the second inner rotor 30 ', and the outer periphery of the resolver holder 32' is opposed to the detector.
  • the resolution of the resolver stator 35 ', 36' is high resolution incremental resolver stator 35, and the absolute resolver stator 36 'that can detect the position of the rotor in one rotation.
  • the resolver holder 32 'and the second inner rotor 30' are magnetic bodies so that electromagnetic noise from the motor field and the motor coil is not transmitted to the resolver stators 35 'and 36' which are angle detectors. Carbon steel is used as a material, and chromate plating is applied after processing to prevent fouling.
  • the second inner rotor 30 ′ rotates at the same speed by the magnetic coupling action with respect to the second outer rotor 21 ′, that is, rotates with the rotation angle of the second outer rotor 21 ′.
  • the parts forming the motor, the bearing 33 is provided as a single resolver without using uzing, and therefore, the eccentricity adjustment with the single resolver is performed before being incorporated into the housing. Since it is possible to adjust the accuracy of the resolver coil position, etc., there is no need to provide separate adjustment holes or cutouts on both flanges of the housing.
  • the rotating wheel of the bearing device 19 ′ that is rotatably supported by the second outer rotor 21 ′ is fitted to the rotor yoke 21 b ′, which is easy to obtain machining accuracy and whose linear expansion coefficient is substantially the same as the driving wheel of the bearing device 19 ′.
  • the incremental resolver rotor 34a ' has a plurality of slot tooth rows having a constant pitch, and the outer circumference of the incremental resolver stator 35.
  • the surface is provided with teeth that are shifted in phase with respect to the incremental resolver rotor 34a ′ at each magnetic pole parallel to the rotation axis, and a coil is wound around each magnetic pole.
  • the reluctance change is detected so that the wave component has an n period, is digitalized by the resolver control circuit shown in FIG. 53, and is used as a position signal, so that the incremental resolver rotor 34a ′, that is, the first 2The rotation angle (or rotation speed) of the inner rotor 30 'is detected.
  • Resolver rotors 34a, 34b, and resolver stators 35, 36, and The detector is configured with.
  • the magnetic shield plates 25 and 41 are arranged between the first outer rotor 21 and the second outer rotor 21 ', mutual magnetic interference is suppressed. However, it avoids malfunctions such as erroneous driving and rotation.
  • the outer peripheral edge 12b of the flange portion 12a extending between the direct drive motors Dl and D2 in the main body 12 is made of carbon steel, which is a magnetic material, between the first stator 29 and the second stator 29 '.
  • the magnetic fields that shield each other's magnetic field are included. Functions as a shield.
  • the first stator 29 and the second stator 29 ' are vertically arranged around the flange portion 12a, and the resolver is arranged radially inside thereof.
  • the main body 12 has a hollow structure, and the flange portion 12a has at least one radial through hole 12d communicating with the center through which the motor wiring is drawn out to the center of the main body 12. It has a structure.
  • at least one notch 12e, 12e is provided at each end of the main body 12, and the resolver wiring is drawn out to the center of the main body 12 through these.
  • the angle of the stator and resolver can be adjusted. Therefore, if a separate facility for rotationally driving the reference outer rotor is prepared, the angle of the resolver relative to the stator can be adjusted with high accuracy by setting the main body 12 incorporating the stator and resolver in the facility. Therefore, it is possible to prevent the angle positioning accuracy from being lowered due to the deviation of the commutation, and to improve the compatibility of the drive control circuit with the two-axis coaxial motor of the present invention.
  • FIG. 54 is a block diagram showing a drive circuit for the direct drive motors Dl and D2.
  • 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 sent from the CPU to the three-layer amplifier (AMP).
  • the drive signal is output, and the drive current is supplied to the direct drive motors Dl and D2 with a three-layer amplifier (AMP) force.
  • AMP three-layer amplifier
  • the resolver signal is output from the resolver stator 35, 36, 35, 36, which has detected the rotation angle as described above, and is output to the resolver digital converter (RDC).
  • the CPU input after digital conversion judges whether or not the outer rotor 21, 21 'has reached the command position, and when it reaches the command position, it stops the drive signal to the 3-layer amplifier (AMP). Stop rotation of outer ports 21, 21 '. This enables servo control of the outer rotors 21, 21 '.
  • FIG. 55 is a cross-sectional view showing a four-axis coaxial motor system that works on a modification of the present embodiment.
  • the partition wall holder 113a is airtightly coupled to the upper disc portion 110 attached to the upper surface of the main body 12 connected in series via the O-ring OR, and the outer peripheral surface thereof.
  • the upper end of thin cylinder 113b is TIG welded.
  • the lower end of the thin-walled cylinder 113b is TIG welded to the holder 15 as in the above-described embodiment.
  • Bulkhead holder 113a and thin-walled cylinder 113b and holder 15 constitute a partition wall. Used in common.
  • the upper surface of the disc part 110 is closed by the lid member 101, and a bearing holder 107 attached to the outer periphery thereof supports the bearing 19.
  • the disk part 110, the lid member 101, and the bearing holder 107 have high corrosion resistance! Use austenitic stainless steel as the material! /
  • the outer peripheral surface of the upper disk part 110 where the bearing holder 107 is attached is located radially inward of the thin cylinder 113b. Therefore, if the bearing holder 107 is removed from the upper disk part 110, the four outer rotors 21, 21 ′ can be removed upward without disassembling the upper disk part 110. Therefore, it is possible to facilitate work that does not require disassembly of the airtight structure during maintenance.
  • the magnetic shield plates 25 'and 25' are arranged between the second outer rotors 21 and 21 at the center, so that mutual magnetic interference is suppressed. This avoids malfunctions such as erroneous driving and companionship.
  • a magnetic shield plate 125 whose outer peripheral force extends in the radial direction to the inside of the thin cylinder 113b is disposed.
  • the magnetic 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 adjacent second outer rotor 21 ′ is affected by the leakage magnetic flux.
  • the force described using the example using the surface magnet type 32-pole 36-slot outer rotor brushless motor is not limited to this type of motor.
  • any brushless motor can be applied, and other magnetic pole types such as a permanent magnet embedded type, other slot combinations, or an inner rotor type may be used.
  • a configuration may be adopted in which the number of rotor poles and the number of slots of adjacent axes in the axial direction are different.
  • the first axis is 32 poles and 36 slots
  • the second axis is 24 poles and 27 slots
  • the first and third axes are 32 poles and 3 6 slots. If the 2nd and 4th axes are configured as 24 poles and 27 slots, mutual generation of thrust in the rotational direction to the rotor and magnetic coupling device by the magnetic field of each axis will occur. Interference can be prevented.
  • the rotor permanent magnet is a neodymium (Nd-Fe-B) -based magnet, and nickel coating is used as an example of coating to improve corrosion resistance.
  • This material is not limited to the surface treatment, but is changed as appropriate depending on the environment in which it is used.
  • samarium-cobalt (Sm'Co) is less susceptible to high temperature demagnetization depending on the temperature conditions during beta-out System magnets should be used, and if used in ultra-vacuum, a titanium nitride coating with a high outgas barrier should be applied.
  • the yoke is made of low-carbon steel and explained with an example of nickel plating.
  • This material is not limited to surface treatment, and is appropriately changed depending on the environment used. Especially for surface treatment, if it is used in ultra-vacuum, it should be applied with force with few pinholes such as Zen plating, clean soldering, and titanium nitride coating.
  • the method for fastening the permanent magnet to the yoke has been described using an example in which a non-magnetic wedge is tightened from the outer diameter side of the yoke with a screw, but it may be changed as appropriate depending on the environment in which it is used. May be bonded or other fastening methods.
  • bearings 19 and 19 have been explained using examples of vacuum grease lubricated 4-point contact ball bearings, but this is not limited to this type, material, and lubrication method. It can be changed as appropriate depending on conditions, rotational speed, etc., and it can be a cross roller bearing. In the case of a 4-axis coaxial motor, it can be supported by another bearing to further increase mechanical rigidity. If a multi-point contact bearing cannot be used, such as when rotating at high speeds, a bearing that supports the rotor of each shaft and another bearing may be configured to apply preload as deep groove ball bearings or angular bearings. When used in an ultra-vacuum, it is possible to use a metal-lubricated material that does not emit gas, such as a metal ring plated with a soft metal such as gold or silver.
  • the inner rotor functioning as a magnetic coupling has been described as using a permanent magnet and a back yoke.
  • the material and shape of the permanent magnet and the back yoke are not limited thereto.
  • the number of poles may not be the same as that of the outer rotor, or the width may not be the same. Even salient poles without permanent magnets are acceptable. Yes.
  • a resolver is used as an angle detector
  • it can be appropriately changed depending on manufacturing cost and resolution, and for example, an optical rotary encoder may be used.
  • the material, shape, and manufacturing method of the structural parts and partition walls arranged in and out of the other partition walls are appropriately changed depending on the manufacturing cost, the environment used, the load conditions, the configuration, and the like.
  • the thrust in the rotation direction is applied to the magnetic force coupling used for each rotor and rotation detector by the magnetic flux that leaks the magnetic coupling force used for the rotor, stator, and resolver of each axis.
  • magnetic shields for shielding each other's magnetic field are arranged between the rotors of each axis, or the electromagnetic fields generated by the rotor, stator and resolver force of each axis.
  • a magnetic shield is provided to shield each other's electromagnetic field, or the number of rotor poles and the number of stator slots in the axially adjacent axes are changed.
  • the direct drive motor of the present embodiment is not limited to a vacuum atmosphere, Can be used in the outside atmosphere.
  • a reactive gas for etching may be introduced into the vacuum chamber after evacuation, but in the direct drive motor of this embodiment, the inside and outside are shielded by the partition walls. Therefore, there is no possibility that the motor coil or the insulating material will be etched.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)
  • Motor Or Generator Frames (AREA)

Abstract

Dispositif de support de rotation dans lequel le jeu du roulement est éliminé sans recours à un élément à ressort. Les lignes de flux magnétique s'écoulant d'un aimant permanent (30a) vers un aimant permanent (21a) génèrent une force d'attraction électromagnétique propre à déplacer l'aimant permanent (30a) à force vers son axe. Lorsque cet aimant (30a) est déplacé vers son axe, la bague intérieure du roulement (33) est déplacée à force dans le sens de l'axe via un premier moteur intérieur (30), ce qui élimine le jeu du roulement (33).
PCT/JP2006/321276 2006-10-25 2006-10-25 Dispositif de support de rotation WO2008050418A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2006/321276 WO2008050418A1 (fr) 2006-10-25 2006-10-25 Dispositif de support de rotation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2006/321276 WO2008050418A1 (fr) 2006-10-25 2006-10-25 Dispositif de support de rotation

Publications (1)

Publication Number Publication Date
WO2008050418A1 true WO2008050418A1 (fr) 2008-05-02

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106998128A (zh) * 2016-01-26 2017-08-01 刘凯平 一种调速装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006109655A (ja) * 2004-10-07 2006-04-20 Nsk Ltd ダイレクトドライブモータ
JP2006109654A (ja) * 2004-10-07 2006-04-20 Nsk Ltd モータシステム
JP2006254605A (ja) * 2005-03-11 2006-09-21 Nsk Ltd ダイレクトドライブモータ及びモータシステム
JP2006254604A (ja) * 2005-03-11 2006-09-21 Nsk Ltd モータシステム

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006109655A (ja) * 2004-10-07 2006-04-20 Nsk Ltd ダイレクトドライブモータ
JP2006109654A (ja) * 2004-10-07 2006-04-20 Nsk Ltd モータシステム
JP2006254605A (ja) * 2005-03-11 2006-09-21 Nsk Ltd ダイレクトドライブモータ及びモータシステム
JP2006254604A (ja) * 2005-03-11 2006-09-21 Nsk Ltd モータシステム

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106998128A (zh) * 2016-01-26 2017-08-01 刘凯平 一种调速装置

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