JP6710055B2 - Scale integrated linear motor and linear motion unit equipped with the linear motor - Google Patents

Description

The present invention relates to a linear motor including a coil and a permanent magnet, and more particularly to a scale-integrated linear motor including a scale for position control and a linear motion unit including the scale-integrated linear motor.

By the action of a magnetic field generated from a permanent magnet body formed by combining a plurality of cylindrical permanent magnets in series, and an electric current applied to a cylindrical coil combined so as to concentrically include the permanent magnet body A coreless cylindrical linear motor that obtains thrust for driving a coil in the direction of the central axis of a permanent magnet is known (Patent Document 1). This linear motor is sometimes called a “shaft motor”.

As shown in FIG. 8, this type of linear motor has a rod-like structure in which a plurality of cylindrical permanent magnets 101 magnetized in the central axis direction are connected in series and a minute gap is formed around the cylindrical permanent magnet 101. It has a basic structure in which the above coils 102 are slidably combined. The plurality of permanent magnets 101 are combined with the same magnetic poles facing each other such that the N poles and the S poles are alternately arranged to form a shaft (fixed portion). In FIG. 8 , the coil 102 is composed of at least three U-phase, V-phase, and W-phase coils to form a three-phase linear motor, and each coil has a phase difference of 120° electrically. An electric current is passed through to become a mover (movable part). By controlling the energization of the coil 102, the mover can be moved linearly along the shaft.

JP, 10-313566, A JP, 2002-307360, A JP, 2005-165767, A

In order to drive this type of linear motor, it is necessary to perform feedback control using a linear encoder, a servo amplifier, etc. that detects the position of the mover. Therefore, in addition to the cost of the linear encoder itself, the cost of highly accurate machining for the mounting portion of the linear encoder and the cost of highly accurate mounting parts are incurred. This is because highly accurate flatness, parallelism, and the like are required for the part to which the linear encoder is attached. As a result, including the linear motor and its peripheral components often results in an expensive device. Further, due to these peripheral parts, the structure of the device is often restricted.

Generally, in order to perform highly accurate positioning in a linear motor, it is required to reduce the Abbe error and to reduce the moment generated in the movable part in order to stabilize the posture during driving. (Brian's alignment principle). In order to achieve this, it is desirable that the thrust generation position of the linear motor, the position of the linear encoder for detecting the position of the movable portion, and the work position are arranged as close as possible. However, the shape of the linear encoder is often restricted by the fact that it must be arranged on an axis having a center axis different from the center axis of movement of the movable portion of the linear motor (Patent Document 2).

In order to solve these problems, the magnetic field generated by the permanent magnet that constitutes the shaft (stator) of the linear motor is read by a sensor such as a Hall element installed in the movable part, and the position is detected as an alternative to the linear encoder. There are also things to do. However, since the permanent magnets forming the stator of the linear motor are not magnetized for the purpose of realizing the linear encoder, the signal output from the sensor contains ripple components. Therefore, the position information generated from the output signal of the sensor includes an error, and the reproducibility and absolute accuracy of the position are deteriorated when the actual driving is performed using a servo amplifier or the like.

Also, since the servo amplifier determines the three-phase drive current based on the position information of the linear encoder, if there is an error in the position information, the drive current will be disturbed and abnormal heating of the linear motor will occur. Is also connected.

In particular, in the case of a direct drive motor such as a linear motor, the drive current is equal to the drive thrust, so that it cannot be used in a device that requires precise thrust control.

As still another example of the linear motor, the coil side of the cylindrical linear motor is used as a fixed portion, the shaft side of the cylindrical linear motor is used as a movable portion that can move in the central axis direction, and then the shaft of the cylindrical linear motor is used. There is a system in which a rotary motor is connected to obtain both the linear motion and the rotary motion of the shaft. In this case, the weight of the rotary motor is added as a load to the linear motor, which makes it difficult to reduce the size. Further, since the control signal of the rotary motor and the power supply cable are pulled out from the movable portion, there are problems in the cable fixing method and the service life.

As another structure of the linear motor that realizes both linear and rotary movements of the shaft, the rotary motor and the linear motor are arranged on different axes, and the rotational force of the rotary motor is transferred to the shaft of the linear motor by gears, belts, pulleys, etc. There is also a transmission method (Patent Document 3), but the positioning accuracy often deteriorates due to wear of the transmission mechanism or the like.

For the above reasons, it has been difficult to construct a device that realizes space-saving and highly accurate linear motion and rotary motion.

In view of the above problems, it is an object of the present invention to provide a scale-integrated linear motor that solves any of the above problems.

According to the first aspect of the present invention, a magnet portion for a linear motor, in which a plurality of permanent magnets are connected in series and fixed to a supporting member longer than the connected plurality of permanent magnets to form a shaft, A linear motor having a tubular coil for linear motor, which is combined with the shaft in a concentric manner via a gap so as to be relatively movable along the axial direction of the shaft, A sensor head for a linear encoder is arranged at a position adjacent to one end side in the axial direction of the coil so as to be movable relative to the shaft together with the coil, and corresponds to a region including a relative movement range of the sensor head. There is provided a scale-integrated linear motor characterized in that a scale for a linear encoder is provided on the outer periphery of the support member.

According to a second aspect of the present invention, there is provided a linear motion unit including the scale-integrated linear motor according to the first aspect.

According to a third aspect of the present invention, a magnet portion for a linear motor, in which a plurality of permanent magnets are connected in series and fixed to a supporting member longer than the plurality of connected permanent magnets to form a shaft, , A cylindrical linear motor coil combined with the shaft so as to be relatively movable along the axial direction of the shaft while concentrically containing the shaft, and a plurality of the connected coils. In a linear motor provided with a rotation motor that is arranged at a position on one end side in the axial direction of the permanent magnet and that drives the shaft to rotate about the central axis thereof, in the axial direction of the plurality of connected permanent magnets. The position adjacent to the other end side, the position between one end side in the axial direction of the plurality of connected permanent magnets and the rotation motor, or the rotation opposite to the connected plurality of permanent magnets. A linear encoder sensor head and a rotary encoder sensor head are arranged at a position adjacent to the end of the motor for linear motor so as to be relatively movable with respect to the shaft together with the coil for the linear motor and the coil for the rotary motor. It is characterized in that a grid-like scale for linear encoders and rotary encoders is provided on the outer periphery of the support member corresponding to a common area including the relative movement range of the sensor head for linear encoder and the sensor head for rotary encoder. A scale-integrated linear motor is provided.

According to a fourth aspect of the present invention, there is provided a linear motion unit including the scale-integrated linear motor according to the third aspect.

According to the present invention, since a linear scale can be formed on the shaft of a linear motor to form a linear encoder, position and thrust control can be performed with high accuracy, and Abbe's error is small, thus saving space. It is possible to provide an inexpensive linear motor integrated with a scale.

It is a figure for demonstrating the main part of 1st Embodiment of the scale integrated linear motor which concerns on this invention about three examples. It is a figure for demonstrating an example of the three-phase rotary motor in the scale integrated linear motor shown in FIG. It is a figure for demonstrating an example of the multi-pole three-phase rotary motor in the scale integrated linear motor shown in FIG. FIG. 3 is a diagram showing a general drive circuit in the three-phase rotary motor shown in FIG. 2. FIG. 2 is a perspective view and a perspective sectional view showing an example in which the scale-integrated linear motor shown in FIG. 1 is unitized into a linear motion unit. FIG. 2 is a perspective view and a perspective sectional view showing an example of a case where the scale-integrated linear motor shown in FIG. 1 is unitized and the shaft is hollow to be a linear motion unit. It is a figure for demonstrating the principal part of 2nd Embodiment of the scale integrated linear motor which concerns on this invention. It is a perspective view for explaining the basic structure of a general cylindrical type linear motor.

A first embodiment of a scale-integrated linear motor according to the present invention will be described with reference to FIG. The scale-integrated linear motor according to the first embodiment includes a direct acting portion that functions as a three-phase linear motor that drives the shaft in the central axis direction and a rotating portion that functions as a rotary motor that rotates the shaft around the central axis. And a detection unit for detecting the position of the shaft in the direction of the central axis and the rotational position, so to speak, a direct-acting rotation integrated motor.

FIG. 1 is a partially cutaway view of a main part of the scale-integrated linear motor according to the first embodiment, that is, the linear motion part 100, the rotation part 200, and the detection part 300. In the first embodiment, the linear motion section 100 is realized by a three-phase linear motor, the rotation section 200 is realized by a three-phase rotation motor, and the detection section 300 is rotated by a linear encoder using a linear scale and a sensor and a rotation scale and a sensor. I am trying to realize it with an encoder. Note that FIG. 1 shows three examples (a), (b), and (c) in which the installation position of the detection unit 300 is different.

With reference to FIG. 1( a ), in the linear motion part 100, a shaft 10 which is a magnet part by accommodating a plurality of cylindrical (or ring) permanent magnets 3 connected in series in a pipe 1 is provided. It acts as a movable portion (movable element) of a three-phase linear motor that is movable in the central axis direction. The permanent magnet 3 is magnetized in the direction of its central axis, and is connected by facing the same magnetic pole so that the N pole and the S pole are alternately arranged. The pipe 1 is preferably made of a non-magnetic material and has a length that extends not only to the linear motion part 100 but also to the rotating part 200 and the detecting part 300. The permanent magnet 3 may be cylindrical. The stroke of the shaft 10 can be determined by the number of permanent magnets 3. The assembly of the plurality of permanent magnets 3 and the support structure of the shaft 10 will be described later.

A coil body 2 is assembled around the pipe 1 in the linear motion portion 100 so as to concentrically include the shaft 10 via a minute gap. The coil body 2 is fixed to a base (not shown) and acts as a fixed portion (stator) of the three-phase linear motor. The coil body 2 includes at least one set of three U-phase, V-phase, and W-phase coils. Here, two sets (six) of the coils are connected to each other in the central axis direction of the shaft 10. It becomes.

A three-phase linear motor having such a linear motion section 100, when a drive current having a phase difference of 120° is applied to the U-phase, V-phase, and W-phase of two coils from an external power source (not shown) A thrust in the central axis direction is generated between the permanent magnet 3 and the shaft 10 to move in the central axis direction, and the thrust can be taken out of the three-phase linear motor by the shaft 10. Since such a three-phase linear motor itself is known, detailed description thereof will be omitted.

The rotating unit 200 accommodates the cylindrical or cylindrical permanent magnet 5 in the pipe 1 as a movable unit (movable element), and encloses the pipe 1 concentrically around the pipe 1 via a minute gap. The coil 4 is combined. The coil 4 includes at least one set of three U-phase, V-phase, and W-phase coils, and the coil 4 is also fixed to a base (not shown) so as to be a fixed portion (stator) of the three-phase rotary motor. Acts as. As shown in FIG. 5B, which will be described later, the coil 4 has a length capable of generating a rotational driving force for rotating the shaft 10 and a load connected thereto within the stroke range of the shaft 10 together with the permanent magnet 5. have.

The permanent magnet 5 of the rotating unit 200 is magnetized in the radial direction and is arranged so as to be concentric with the permanent magnet 3 of the linear motion unit 100. Magnetization of the permanent magnet 5 may be a single pole having only N pole or S pole as shown in FIG. 2 or may be a plurality of poles (here, 2 poles) divided into a plurality in the circumferential direction as shown in FIG. .. The permanent magnet 5 may also be configured by dividing a ring-shaped permanent magnet into a plurality of pieces in the central axis direction.

In FIGS. 2 and 3, for example, the U-phase of the coil 4 will be described. The U-phase coil is a coil formed in a racetrack shape so as to extend in the central axis direction of the pipe 1 (FIG. 1) and has a minute gap. The cross section is formed into a saddle shape so as to extend along the outer periphery of the pipe 1 via the pipe.

FIG. 4 shows an example of a drive circuit for the three-phase rotary motor of the rotary unit 200. The drive circuit includes an inverter circuit 40, a control circuit 44, and a DC power supply 45. The inverter circuit 40 includes arms 41, 42, and 43 for exciting the U-phase winding U, the V-phase winding V, and the W-phase winding W of the three-phase rotary motor. The arm 41 is composed of upper and lower switching elements 41a and 41b in FIG. 4, the arm 42 is composed of upper and lower switching elements 42a and 42b in FIG. 4, and the arm 43 is composed of upper and lower parts in FIG. The switching elements 43a and 43b form a pair. Each switching element is composed of a transistor and a diode connected in parallel. The control circuit 44 outputs a PWM (Pulse Width Modulation) signal to control ON/OFF of each transistor and applies a three-phase AC voltage to the U-phase winding U, the V-phase winding V, and the W-phase winding W. The drive of the three-phase rotary motor is controlled by changing the pulse width of. As described above, the three-phase AC voltage applied to the U-phase winding U, the V-phase winding V, and the W-phase winding W has a phase difference of 120°. Such a drive circuit merely shows an example of a basic configuration for explaining a three-phase rotary motor, and in reality, a servo amplifier or the like is combined with an inverter circuit.

The rotation unit 200 is not limited to a three-phase rotation motor, and may be a single-phase motor, a DC motor, a pulse motor, or the like, as long as the rotation motor has a structure in which the torque does not change when the shaft 10 moves in the linear stroke direction. good. Since this type of rotary motor is well known including a three-phase rotary motor, detailed description thereof will be omitted.

The detection unit 300 forms a scale 8 on the outer circumference of the pipe 1 to serve as a scale for a linear encoder and a rotary encoder. A linear sensor for a linear encoder is provided around the pipe 1 in the region where the scale 8 is formed via a minute gap. A head 6 and a rotation sensor head 7 for a rotary encoder are arranged. The graduations 8 are linear encoder graduations (linear scales) formed in the circumferential direction at equal intervals in the central axis direction of the pipe 1, and the graduations 8 in the central axis direction at equal intervals in the circumferential direction of the pipe 1. A grid shape is formed by including the scale (rotary scale) for the rotary encoder formed so as to extend. The scale 8 is formed in a length range capable of covering a moving region corresponding to the stroke range of the shaft 10. It can be said that the length range capable of covering the movement area corresponding to the stroke range of the shaft 10 includes the movement area of the shaft 10 facing the linear sensor head 6 and the rotation sensor head 7. In other words, it can be said that the formation area of the scale 8 is the outer circumference of the shaft 10 corresponding to the common area including the relative movement range of the linear sensor head 6 and the rotation sensor head 7 with respect to the shaft 10. This also applies to the second embodiment described later. It goes without saying that the pitch of the linear scale and the pitch of the rotary scale are set so as to correspond to the detection accuracy of the linear sensor head 6 and the rotary sensor head 7. The combination of the linear scale and the linear sensor head, and the combination of the rotary scale and the rotary sensor head are preferably optical.

The scale 8 may be directly drawn on the surface of the pipe 1 with a laser or the like, or the scale may be prepared in advance on a film-like sheet and attached to the surface of the pipe 1. In the case of a sheet, the material is preferably a non-magnetic material in consideration of workability, but it is not limited to this.

FIG. 1A shows a configuration in which the linear motion unit 100-rotation unit 200-detection unit 300, that is, the detection unit 300 is disposed on one end side of the shaft 10 closer to the rotation unit 200. As shown in FIG. 1B, the detection unit 300 may be arranged between the linear motion unit 100 and the rotation unit 200. Further, as shown in FIG. 1C, the arrangement configuration of the detection unit 300-the linear movement unit 100-the rotation unit 200, that is, the configuration in which the detection unit 300 is arranged on the other end side of the shaft 10 remote from the rotation unit 200. But good.

1(b) and 1(c), the scale-integrated linear motor is different from the scale-integrated linear motor in FIG. 1(a) only in the position of the detection unit 300. Since the rotating unit 200 and the detecting unit 300 have the same configuration, the description of the configuration of each unit will be omitted.

As described above, the coil body 2 for the three-phase linear motor and the coil 4 for the three-phase rotary motor are each composed of three-phase windings of U-phase, V-phase and W-phase, and are star-connected or delta-connected. It is connected to a driving power source via an inverter, a servo amplifier or the like (not shown). The coil body 2 and the coil 4 each have one set of a combination of U phase, V phase, and W phase as a minimum unit, and can increase the number of sets of UVW according to required thrust or torque.

According to the first embodiment described above, the scale (linear scale) for the linear encoder in the linear motor and the scale (rotary scale) for the rotary encoder in the rotary motor having a rotary shaft concentric with the shaft of the linear motor are used as the shaft. In addition, compared to the example in which the scale is formed on a member different from the shaft directly and in a grid pattern in the common region, the Abbe's error is small and the position and thrust can be controlled with high accuracy. Compared to an example in which a linear scale and a rotary scale are provided in different places, cost reduction and space saving associated with scale production can be realized.

5A and 5B show an example of a case where a scale-integrated linear motor similar to that of the first embodiment is unitized into a linear motion unit. FIG. 5A is a perspective view and FIG. 5B is a perspective sectional view.

The scale-integrated linear motor in the linear motion unit shown in FIG. 5 is different from the scale-integrated linear motor described in FIG. 1, specifically showing the assembly structure of the plurality of permanent magnets 3 and the support structure of the shaft 10. The shaft 10 moves in the vertical direction, so to speak, it is a vertical type.

That is, the plurality of permanent magnets 3 are assembled by the center shaft 15 inserted into the hollow portions of the plurality of permanent magnets 3 and the holding portions 12 and 13 attached to both ends of the center shaft 15. Male screws are formed on at least both sides of the outer periphery of the center shaft 15 over a certain range, and the holding portions 12 and 13 are formed with female screws corresponding to these male screws. The holding portions 12 and 13 can tighten the permanent magnets 3 with a force larger than the repulsive force generated between the permanent magnets 3 to assemble the permanent magnets 3 as shown in FIG. 1. A cylindrical spacer 16 is interposed between the permanent magnet 5 for the rotary motor and the permanent magnet 3 closest to the permanent magnet 5. Similarly, a spacer 17 is also interposed between the permanent magnet 5 and the holding portion 12. The spacers 16 and 17 are preferably made of a non-magnetic material, but not limited to this.

A male screw may be formed over the entire length of the outer circumference of the center shaft 15. In this case, female screws can be formed on the inner circumferences of the permanent magnets 3 and 5 as well as on the inner circumferences of the spacers 16 and 17, as required, to facilitate the assembly to the center shaft 15.

The coil body 2 of the linear motion section 100, the coil 4 of the rotation section 200, and the linear sensor head 6 and the rotation sensor head 7 of the detection section 300 are integrally fixed to the base 9 by resin molding. Of course, the coil body 2 of the linear motion section 100, the coil 4 of the rotation section 200, and the linear sensor head 6 and the rotation sensor head 7 of the detection section 300 are integrally molded by resin molding. You can also do it.

Projections 9-1 and 9-2 are formed above and below the base 9 so as to project in a direction perpendicular to the main body of the base 9. Further, bearings 18 and 19 for supporting the holding portions 12 and 13 in a linearly movable and rotatable manner are provided on the projecting portions 9-1 and 9-2, respectively. An example of the structure for locking the shaft 10 at the lower limit position of its stroke will be described. For example, it can be realized by providing a stopper member (not shown) on at least one of the holding portions 12 and 13. The holding portions 12 and 13 in contact with the bearings 18 and 19 are preferably made of metal having excellent wear resistance, but can be made of other materials by using a resin such as a hydrostatic bearing or engineering plastic. .. It is also possible to extend both sides of the pipe 1 and use the extended portion as it is as a holding portion. In this case, as described above, the center shaft 15 is formed with a male screw over its entire length.

The linear motion unit of FIG. 5 has a structure in which the plurality of permanent magnets 3 are tightened by screwing the holding portions 12 and 13 from both ends through the center shaft 15, but the center shaft is eliminated and the holding portions 12 and 13 and the pipes are removed. It is also possible to form a shaft having a plurality of permanent magnets 3, permanent magnets 5 and the like built in the pipe 1 by caulking 1 and fixing them by welding, brazing or the like.

It is also possible to mold the coil body 2, the coil 4, the linear sensor head 6 and the rotation sensor head 7 individually with resin, and fix them separately to the base 9. In FIG. 5A, reference numeral 20 denotes a cable for supplying electric power to the coil body 2 and the coil 4, and a signal line for extracting a detection signal from the linear sensor head 6 and the rotation sensor head 7.

Although the shaft 10 side is the movable part and the coil side is the fixed part in the linear motion unit of the first embodiment shown in FIG. 1 and FIG. 5, the shaft 10 side is the fixed part and the coil side is the fixed part depending on the application. It can also be a movable part. In this case, to explain with reference to FIG. 5, the holding portions 12 and 13 are fixed at the projecting portions 9-1 and 9-2, and the shaft 10 serves as a fixed portion, so that the coil body 2, the coil 4, the linear sensor head 6, and the rotation sensor head. An integral molding of 7 and resin is made slidable in the direction of the central axis of the shaft 10 to form a movable part.

FIG. 6 shows a modification of the linear motion unit shown in FIG. As shown in FIG. 6, a through hole that communicates with each of the holding portions 12 and 13 and the center shaft 15 in FIG. 5 is provided to form a shape like the holding portions 12a, 13a, and 15a. Holes 21 can be made. As a result, the shaft 10 can be hollow, and by connecting a pneumatic device (not shown) to one end side (upper end side) of the shaft 10, the other end side (lower end side) of the shaft 10 is reduced in electronic component. Can be used as a means for adsorbing.

A second embodiment of the scale-integrated linear motor according to the present invention will be described with reference to FIG. 7. The scale-integrated linear motor according to the second embodiment includes a linear motion portion that functions as a three-phase linear motor that drives a shaft in the central axis direction thereof, and a detection portion that detects a position of the shaft in the central axis direction. have.

FIG. 7 is a partially cutaway view of a main part of the scale-integrated linear motor according to the second embodiment, that is, the linear motion part 400 and the detection part 500.

Since the linear motion section 400 may have the same structure as the linear motion section 100 described in FIG. 1, it will be briefly described. As described with reference to FIG. 1A, a shaft 10 that is a magnet portion by accommodating a plurality of cylindrical (or ring) permanent magnets connected in series in a pipe 1 is a central axis direction thereof. that act as a movable part of a three-phase linear motor movable (movable element) to. On the other hand, around the pipe 1 in the linear motion section 100, the coil body 2 is combined so as to concentrically include the shaft 10 via a minute gap. The coil body 2 is fixed to a base (not shown) and acts as a fixed portion (stator) of the three-phase linear motor. The coil body 2 includes at least one set of three U-phase, V-phase, and W-phase coils. Here, two sets (six) of the coils are connected to each other in the central axis direction of the shaft 10. It becomes.

As described above, the three-phase linear motor having the linear motion section 100 causes a drive current having a phase difference of 120° to flow from the unillustrated external power source to the U-phase, V-phase, and W-phase of the two coils. Then, a thrust in the central axis direction is generated between each coil and the permanent magnet 3 to move the shaft 10 in the central axis direction, and the thrust can be taken out of the three-phase linear motor by the shaft 10.

The detection unit 500 may have the same structure as the linear encoder in the detection unit 300 described with reference to FIG. That is, the scale 8A is formed on the outer periphery of the pipe 1 to form a linear encoder scale, and the linear sensor head 6 for the linear encoder is arranged around the pipe 1 in the region where the scale 8 is formed with a minute gap. The scales 8A are circumferentially formed at equal intervals in the central axis direction of the pipe 1. The scale 8A is formed over the entire length of the pipe 1 here, but it goes without saying that the scale 8A may be formed within a length range that can cover the movement region corresponding to the stroke range of the shaft 10. As described above, the pitch of the linear scale is set so as to correspond to the detection accuracy of the linear sensor head 6. Further, the combination of the linear scale and the linear sensor head is preferably an optical type.

The scale 8A may be directly drawn on the surface of the pipe 1 with a laser or the like, or the scale may be previously formed on a film-like sheet and attached to the surface of the pipe 1. In the case of a sheet, the material is preferably a non-magnetic material in consideration of workability, but it is not limited to this.

In the second embodiment, all the modifications described in the first embodiment can be applied to the same constituent elements as in the first embodiment. For example, as described with reference to FIG. 5, the coil body 2 and the linear sensor head 6 can be integrally or individually molded with resin to form a fixed portion, and the fixed portion is integrally molded with the base. You can also Also, in the second embodiment, the shaft 10 side is the movable part and the coil side is the fixed part. However, the shaft 10 side may be the fixed part and the coil side may be the movable part depending on the application.

According to the second embodiment described above, the scale (linear scale) for the linear encoder in the linear motor is formed directly on the shaft and in the region adjacent to the coil for the linear motor, so that it is different from the shaft. Compared to an example in which a scale is provided on a member, Abbe's error is small, position and thrust can be controlled with high accuracy, and space saving can be realized.

The scale-integrated linear motor according to the present invention is suitable for, but not limited to, a conveyance section of precision equipment, for example, a conveyance system of a semiconductor manufacturing machine.

1 pipe 2 coil body for linear motor 3 permanent magnet for linear motor 4 coil for rotary motor 5 permanent magnet for rotary motor 6 linear sensor head 7 rotary sensor head 8, 8A scale 9 base 10 shaft (stator)
12, 13 Holding part 18, 19 Bearing 100, 400 Linear motion part 200 Rotating part 300, 500 Detection part

Claims (4)

A magnet portion for a linear motor, in which a plurality of permanent magnets are connected in series and fixed to a supporting member that is longer than the connected plurality of permanent magnets to form a shaft, and the shaft are concentric with a gap therebetween. In a linear motor including a coil for a cylindrical linear motor, which is combined with the shaft so as to be relatively movable along the axial direction of the shaft,
A sensor head for a linear encoder is arranged at a position adjacent to one end side in the axial direction of the coil so as to be movable relative to the shaft together with the coil, and corresponds to a region including a relative movement range of the sensor head. the outer periphery of the support member, comprising a scale for a linear encoder,
The support member is a pipe, and the shaft is configured by accommodating the plurality of permanent magnets in such a manner that the same magnetic poles face each other and are connected in series so that the magnetic poles alternate, and the shaft is formed. A scale-integrated linear motor, characterized in that the scales are directly formed on the entire surface at equal intervals . A linear motion unit comprising the scale-integrated linear motor according to claim 1 . A magnet portion for a linear motor, in which a plurality of permanent magnets are connected in series and fixed to a supporting member that is longer than the connected plurality of permanent magnets to form a shaft, and the shaft are concentric with a gap therebetween. And a coil for a cylindrical linear motor, which is combined with the shaft so as to be relatively movable along the axial direction of the shaft, and at a position on the axial one end side of the connected permanent magnets. A linear motor provided with a rotation motor that rotates the shaft about its central axis.
A position adjacent to the other axial end of the plurality of joined permanent magnets, a position between one axial end of the joined plurality of permanent magnets and the rotation motor, or the joined A linear encoder that is movable relative to the shaft together with the linear motor coil and the rotary motor coil at a position adjacent to the end of the rotary motor on the side opposite to the plurality of permanent magnets. Place the sensor head and the sensor head for the rotary encoder,
On the outer periphery of the support member corresponding to a common area including the relative movement range of the sensor head for linear encoder and the sensor head for rotary encoder, a grid-like scale for linear encoder and rotary encoder is provided ,
The support member is a pipe, and the shaft is configured by accommodating the plurality of permanent magnets with the same magnetic poles facing each other and connected in series so that the magnetic poles are alternately arranged in the pipe. A scale-integrated linear motor, wherein the lattice-shaped scales are directly formed on the entire outer peripheral surface of the corresponding pipe . A linear motion unit comprising the scale-integrated linear motor according to claim 3 .

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