JP5206749B2 - Actuator - Google Patents

Description

  The present invention relates to an actuator in which an output shaft performs two operations of rotation and linear motion.

  Conventionally, in order to realize the rotation operation and the linear motion operation, the present applicants overlap the armature windings of the rotary motor and the linear motor concentrically, and at the same time, the linear motion rotation scale and the stator at one end of the mover. An actuator that directly generates torque and thrust on the output shaft of the mover has been proposed (see, for example, Patent Document 1).

JP 2007-143385 A

The Applicant determined that it was necessary to tackle higher accuracy and higher output of the actuator adapted to market needs while further research and development.
Accordingly, an object of the present invention is to provide an actuator with high accuracy and high output.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 relates to an actuator, and is a support mechanism that is arranged at a plurality of locations in the longitudinal direction of the output shaft so as to be concentric inside the frame, and supports the linear motion direction and the rotational direction of the output shaft. And a motor unit that is concentrically disposed between the support mechanisms in the longitudinal direction of the output shaft, and that drives the output shaft in a linear motion direction and a rotational direction, and a rotation angle of the output shaft is detected. And a detector unit including a second detection unit that detects a displacement of the output shaft in the linear motion direction. The motor unit includes a permanent magnet as a field, and the field magnet. And an armature that is disposed opposite to the magnetic gap and generates a moving magnetic field, and the armature of the motor unit includes a first armature winding that drives the output shaft in a rotation direction; It overlaps with the first armature winding concentrically. Disposed, and a second armature winding for driving said output shaft in the linear motion direction, wherein the support mechanism includes a first bearing for rotatably supporting the output shaft, straight to the output shaft A second bearing that is movably supported, and the second bearing is connected to a collar protruding from an outer cylinder end of the second bearing along the longitudinal direction of the output shaft, the detection of the first detection unit is attached to the collar that protrudes from the outer cylinder end of the second bearing, the other detector is characterized in that attached to the frame.
The invention according to claim 2, in the actuator of claim 1, wherein the support mechanism, said first bearing is mounted for rotatably supporting the output shaft to the frame, of the first bearing the output shaft on the peripheral surface is characterized by having a second bearing for linearly movable support.
According to a third aspect of the present invention, in the actuator according to the first aspect, the detector unit is disposed on the load side of the output shaft, and the motor unit is disposed on the anti-load side of the output shaft. It is said.
According to a fourth aspect of the present invention, in the actuator according to the first aspect, the output shaft is made of a nonmagnetic material.

  According to the present invention, the output per unit volume is high, and a precise rotation operation and linear motion operation can be realized.

Side sectional view of the actuator showing the first embodiment, It is explanatory drawing of the magnetic field part of the needle | mover of FIG. 1, Comprising: (a) is sectional drawing seen from the side surface, (b) is sectional drawing seen from the X direction which follows the A cross section and B cross section of (a). , The expanded view which shows the arrangement | positioning relationship of the armature winding and permanent magnet in 1st Embodiment, Side sectional view of an actuator showing a second embodiment, Side sectional view of an actuator showing a third embodiment, Side sectional view of an actuator showing a fourth embodiment, Side sectional view of an actuator showing a fifth embodiment, Side sectional view of an actuator showing a sixth embodiment, Side sectional view of an actuator showing a seventh embodiment Side sectional view of an actuator showing an eighth embodiment

  Hereinafter, the present embodiment will be described with reference to the drawings.

FIG. 1 is a side sectional view of an actuator showing a first embodiment. The actuator will be described with reference to FIG.
In FIG. 1, the actuator that performs linear motion rotation according to the first embodiment includes a stator 100 and a mover 200, and the stator 100 and the mover 200 of the actuator include a detector on the load side of the output shaft 201. The part 100b and the motor part 100a are arranged on the side opposite to the load. The actuators shown in the first embodiment and other embodiments described later are installed so that the θ direction is the rotational direction so that the X direction shown in the drawing is downward in the vertical direction.

The motor unit 100a includes a cylindrical second frame 102 that also serves as an armature core on the stator 100 side, a θ armature winding 103 that generates a rotating magnetic field in the rotation direction, and an X electric machine that generates a traveling magnetic field in the linear motion direction. The child windings 104 are provided so as to overlap in a concentric manner. The second frame 102 is provided with a motor terminal (not shown) for supplying external power to the θ armature winding 103 and the X armature winding 104. On the other hand, on the side of the mover 200 of the motor unit 100a, a field unit 202 is provided on the output shaft 201 so as to be opposed to the inside of the X armature winding 104 via a magnetic gap. The output shaft 201 is made of stainless steel, which is a nonmagnetic material.
As described above, the motor unit 100a can shorten the length in the longitudinal direction of the actuator by arranging the θ armature winding 103 and the X armature winding 104 in a concentric manner so that the output per unit volume can be reduced. Can be increased.

The detector unit 100b includes a linear motion detector unit 300 that detects displacement of the output shaft 201 in the linear motion direction, and a rotation detector unit 400 that detects displacement of the output shaft 201 in the rotational direction.
The linear motion detector unit 300 includes a cylindrical optical linear scale 301 fixed to the outer periphery of the output shaft 201 and an optical linear sensor head 302 fixed to the inner periphery of the first frame 101. . The rotation detector unit 400 includes a θ encoder 401 fixed to a ball spline 106a of the θX bearing unit 106, which will be described later, via a collar 403, and a rotation sensor head 402 fixed to the first frame 101. A permanent magnet is used for the θ encoder 401 constituting the rotation detector 400, and the rotation sensor head 402 is equally arranged on the inner side of the first frame 101 so as to face the permanent magnet with a gap. Four magnetic detection elements such as MR elements and Hall elements are used to constitute a so-called magnetic encoder. The first frame 101 is provided with a detector terminal (not shown) that supplies power to the linear motion detector unit 300 and the rotation detector unit 400 from the outside and outputs detection signals of the position X and the angle θ. Yes.

The support mechanism includes a load-side bracket 107 on the load side of the first frame 101 where the detector unit 100b is disposed, and an anti-load-side bracket 108 on the non-load side. The load side bracket 107 and the anti-load side bracket 108 are respectively provided with θX bearing portions 106 each composed of one ball spline 106a and two bearings 106b. An end bracket 109 is provided on the anti-load side of the second frame 102 in which the motor unit 100a is disposed, and the inner periphery of the end bracket 109 is composed of one ball spline 106a and one bearing 106b. The θX bearing portion 106 is disposed.
As described above, the load side of the output shaft 201 is directly moved in the X direction by the ball splines 106a constituting the θX bearing portions 106 provided at the two positions of the load side bracket 107 and the anti-load side bracket 108 of the first frame 101, respectively. Since the output shaft 201 and the ball spline 106a are supported so as to be rotatable in the θ direction by two bearings 106b provided at the same location as the ball spline 106a, the output shaft 201 and the ball spline 106a are supported by the stator 100. The output shaft 201 on which the detector unit 100b is arranged is supported with respect to the portion of the first frame 101, and can be freely moved by rotating in the θ direction and linearly moving in the X direction. In addition, since the θ encoder 401 is provided at the part of the ball spline that constitutes the θX bearing portion 106 on the load side of the output shaft 201, the load side length of the output shaft 201 that constitutes the detector portion is shortened. Can do. A load (not shown) is provided at the tip of the output shaft end 201, and the load (not shown) can be freely moved in the θ direction and the X direction.
Further, the anti-load side of the output shaft 201 is controlled by the ball splines 106a constituting the θX bearing portions 106 provided at two locations of the anti-load side bracket 108 of the first frame 101 and the end bracket 109 of the second frame 102, respectively. The output shaft 201 and the ball spline 106a are supported so that they can be rotated in the θ direction by bearings 106b provided at two locations on the same part as the ball spline 106a. The output shaft 201 on which the motor unit 100a is disposed is supported by both ends with respect to the second frame 102 portion of the child 100, and is freely movable in the θ direction and the X direction.

2A and 2B are explanatory views of the field portion of the mover of FIG. 1, wherein FIG. 2A is a cross-sectional view seen from the side surface, and FIG. FIG. The arrow (→) in the figure represents the magnetization direction of the permanent magnet, and the polarity is S → N.
The field portion 202 is provided with a plurality of block-shaped permanent magnets (hereinafter referred to as block magnets) 204 a and 204 b on the outer periphery of a cylindrical field yoke 203. The block magnet 204a is magnetized to the outer peripheral side N pole and the inner peripheral side S pole, and the block magnet 204b is magnetized on the contrary. The block magnets 204a and 204b are opposed to the X armature winding 104 through a gap.

FIG. 3 is a development view showing an arrangement relationship between the armature winding and the permanent magnet in FIG.
Each of the block magnets 204a and 204b is composed of six pieces. The block magnets 204a are arranged every 2λ in the θ direction (λ is the pole pitch in the θ direction = electrical angle 180 degrees), and the block magnets 204b are also arranged every 2λ in the θ direction. Furthermore, the block magnets 204a and 204b are arranged so as to be shifted by λ in the θ direction and γ in the X direction (γ is the X-direction pole pitch = electrical angle 180 degrees). Therefore, the number of magnetic field poles is 12 in the θ direction and 2 in the X direction.
The θ armature winding 103 and the X armature winding 104 are arranged as schematically shown by the thick black lines through the block magnets 204a and 204b and the air gap. The θ armature winding 103 is composed of 12 concentrated winding coils (hereinafter referred to as saddle-shaped coils 103a) having a coil end portion having an arc shape, each including three U, V, and W phases. ing. The interval at which the saddle coils 103a are arranged in the θ direction is λ × 4/3 (electrical angle 240 degrees). Since the interval between the in-phase saddle coils 103a is 720 degrees in electrical angle, the three in-phase saddle coils 103a are connected so that all three currents have the same direction. On the other hand, the X armature winding 104 is composed of a total of 12 ring coils 104a concentrated in a cylindrical shape, each having four U, V, and W phases. The interval of the ring-shaped coil 104a arranged in the X direction is γ / 3 (electrical angle 60 degrees), and the entire length of the X armature winding 104 in the X direction is 4γ (= γ / 3 × 12). is there. Since the interval between the ring coils 104a of the in-phase is γ (electrical angle 180 degrees), the four in-phase ring coils 104a are wired so that the direction of the current is normal, reverse, normal, and reverse. Has been.

Next, the operation will be described.
The actuator configured in this manner generates torque in the mover 200 due to the action of the magnetic field generated by the block magnets 204 a and 204 b by passing a current through the θ armature winding 103, and the X armature winding 104. When a current is passed through the armature 200, a thrust is generated in the mover 200 by the action of the magnetic field generated by the block magnets 204a and 204b. FIG. 3 is a diagram in which current is supplied to the θ armature winding 103 and the X armature winding 104 at a phase where the U phase is maximum, and a Lorentz force is generated by the current flowing in the direction of the arrow shown in the figure. The mover 200 generates torque in the θ + direction and thrust in the X + direction. In this way, torque and thrust are directly generated in the mover 200 to perform the rotation operation and the linear motion operation.

  As described above, the feature of the first embodiment is that the detector unit 100b is arranged on the load side and the motor unit 100a is arranged on the non-load side, and each θX bearing unit 106 is replaced with one ball spline 106a. The load side and the anti-load side of the first frame 101 are constituted by two bearings 106b and support the θX bearing part 106 on both sides of the detector part 100b and on both sides of the motor part 100a. A configuration in which the θX bearing portion 106 is provided on the non-load side of the second frame 102, a θ encoder 401 attached to the load side ball spline 106a of the output shaft 201 via a collar 403, and a gap in the θ encoder 401 A portion having a configuration in which a rotation detector 400 including a rotation sensor head 402 arranged evenly on the circumference of the first frame 101 so as to face each other is provided. It is.

Therefore, in the first embodiment, the motor unit can shorten the length in the longitudinal direction of the actuator by arranging the θ armature winding and the X armature winding in a concentric manner so that the length per unit volume is reduced. Output can be increased, and a high output actuator can be provided.
In addition, the θX bearing part is composed of one ball spline and two bearings each, and the θX bearing parts are arranged on both the load side and the anti-load side of the detector part. The backlash and eccentricity of the output shaft can be eliminated, and the straightness of the output shaft and the accuracy of rotational runout can be improved. Since the straightness of the output shaft and the accuracy of rotational runout can be improved, the straightness of the linear scale of the linear motion detector placed on the output shaft and the rotational shake accuracy of the θ encoder of the rotational detector can be improved. And the angle in the rotation direction can be detected with high accuracy.
In addition, by arranging an end bracket on the anti-load side of the motor part and supporting the output shaft via the θX bearing part, the θX bearing part is arranged on both the load side and the anti-load side of the motor part. Since it is equivalent to the configuration, it is possible to eliminate the play and eccentricity of the field part, and hence the play and eccentricity of the output shaft can be eliminated, and the straightness of the output shaft and the accuracy of the rotational runout can be improved. .
In addition to the configuration in which the detector unit is arranged on the load side of the output shaft and the motor unit is arranged on the non-load side, a θ encoder is provided at the part of the ball spline that constitutes the θX bearing unit on the load side of the output shaft. Therefore, the distance between the load (not shown) provided at the tip of the output shaft constituting the detector unit and the detector unit can be shortened. For example, when current is supplied to the θ armature winding or the X armature winding, heat is generated in the motor unit, and even if the negative side of the output shaft is thermally expanded by the generated heat of the motor unit, the output shaft Since the distance between the load (not shown) on the load side and the detector section is shortened, thermal deformation in the linear motion direction of the output shaft can be reduced, and position errors in the linear motion direction of the output shaft can be reduced. .
A magnetic encoder comprising a θ encoder made of a permanent magnet provided at a ball spline portion on the load side of the output shaft, and a magnetic detecting element made of an MR element or the like provided through the θ encoder and a gap. Since the θ encoder is rotatably supported by the bearings on the load side and the anti-load side of the output shaft, the radial gap of the bearing becomes an average gap fluctuation, and a magnetic gap of several μm is obtained. The detection error of the magnetic encoder can be reduced.
Also, in the assembly of the field part, the block magnet is magnetized so that it needs to be handled with care. In the assembly of the output shaft, since it affects the detection accuracy of the linear motion rotation, care must be taken in attaching the linear scale. Since the output shaft and the field portion are divided, the assembly of the field portion and the assembly of the output shaft can be performed in separate processes, and the assembling work is facilitated.
Further, since the output shaft is constituted by a precisely processed ball spline shaft, the output shaft can be made inexpensive by reducing the length of the output shaft.
Further, since the output shaft is made of stainless steel, which is a non-magnetic material, the output shaft does not pass magnetic flux. Conventionally, the lines of magnetic force due to the magnetic flux leaking from the field part have a line of magnetic force that passes through the output shaft and continues to the detector part. Since the output shaft does not pass the magnetic flux, the leakage flux of the field part to the detector part can be reduced, and the detection error of the detector part generated by the leakage flux of the field part can be reduced.
As described above, the actuator according to the present embodiment minimizes the detection error of the position of the output shaft in the linear motion direction and the angle in the rotational direction and can accurately detect it. The operation can be realized with one actuator.

FIG. 4 is a side sectional view of the actuator showing the second embodiment. In addition, description is abbreviate | omitted about the same component as 1st Embodiment of 2nd Embodiment.
The features of the actuator that performs linear motion rotation according to the second embodiment will be described as follows.
That is, the detector unit of the first embodiment is composed of a linear motion detector unit that detects the displacement of the output shaft in the linear motion direction, and a rotation detector unit that detects the displacement of the output shaft in the rotational direction. On the other hand, the detector unit of the second embodiment basically constitutes a linear motion rotation detector unit 500 in which the functions of the linear motion detector unit and the rotation detector unit of the first embodiment are integrated. It is different. A so-called linear motion rotation detector unit 500 includes a cylindrical linear motion rotation scale 501 fixed to the outer periphery of the output shaft 201 and a linear motion sensor head 502 fixed to the inner periphery of the first frame 101. The displacement of the output shaft 201 in the linear motion direction and the rotational direction is detected.
The first frame 101 is provided with a detector terminal (not shown) that supplies power to the linear motion detector 500 from the outside and outputs a detection signal of the position X and the angle θ.
Further, the mover according to the second embodiment includes an output shaft, a detector unit, and a motor unit b, and the θ armature winding and the X armature winding of the motor unit are concentrically arranged in the longitudinal direction. Basically, the configuration in which the output shaft is supported between the load side and the anti-load side of the detector unit and between the load side and the anti-load side of the motor unit is basically the first implementation. Since it is the same as the form, the description is omitted.
Further, the operation of the second embodiment is basically the same as that of the first embodiment, and the description thereof is omitted.

  Therefore, the second embodiment includes a cylindrical linear motion rotation scale fixed to the outer periphery of the output shaft and a linear motion rotation sensor head fixed to the inner periphery of the first frame as the detector portion of the actuator. By providing a linear motion rotation detector unit that integrates the functions of the linear motion detector unit and the rotation detector unit, the number of parts can be further reduced compared to the first embodiment, and the size can be reduced. By further downsizing, it is possible to eliminate play and eccentricity of the output shaft in the detector section. As a result, the straightness of the output shaft and the accuracy of the rotational runout can be improved, so that the displacement in the linear motion direction and the rotational direction of the output shaft can be easily and accurately detected with a simple configuration.

FIG. 5 is a side sectional view of an actuator showing a third embodiment. Note that the description of the components of the third embodiment that are the same as those of the first embodiment will be omitted.
The features of the actuator that performs linear motion rotation according to the third embodiment will be described as follows, which are different from the first embodiment.
That is, the motor unit of the first embodiment has an armature part in which the θ armature winding and the X armature winding are concentrically overlapped in the second frame, and a field that is disposed opposite to the armature part. The motor unit 100a according to the third embodiment basically includes a θ motor unit composed of a θ armature winding 103 and a θ field unit 205, an X armature winding 104, and an X unit. The X motor part composed of the field part 207 is different in that it is arranged in series in the longitudinal direction of the output shaft 201 inside the second frame 102. In particular, the X field portion 207 of the X motor portion is attached to the output shaft 201, and the θ field portion 205 of the θ motor portion is on the outer periphery of the ball spline 106 a located on the side opposite to the load 108 on the output shaft 201. The other θ armature winding 103 is attached to the provided collar 206, and is attached to the second frame 102.
Note that the configuration in which the θX bearing portion of the third embodiment supports the output shaft between the load side and the anti-load side of the detector portion and between the load side and the anti-load side of the motor portion is basically the first embodiment. Since it is the same as the form, the description is omitted.
Further, the operation of the third embodiment is basically the same as that of the first embodiment, and the description thereof is omitted.

  Therefore, in the third embodiment, a θ motor unit composed of a θ armature winding and a θ field portion, and an X motor portion composed of an X armature winding and an X field portion are concentrically arranged in series in the longitudinal direction. And the field portion of the X motor portion is attached to the output shaft, and the θ field portion is attached to a collar provided on a ball spline located on the side opposite to the load side of the output shaft. Therefore, since the magnetic gap length is shortened when the gap between the X armature winding and the X field portion and the gap between the θ armature winding and the θ field portion are close to each other, the output can be increased. Although the length of the actuator in the longitudinal direction is somewhat longer, the output per unit volume can be increased because the output of the actuator is increased.

FIG. 6 is a side sectional view of an actuator showing a fourth embodiment. In addition, description is abbreviate | omitted about the same component of 4th Embodiment as 1st Embodiment-3rd Embodiment.
The features of the actuator that performs linear motion rotation according to the fourth embodiment will be described below as to differences from the first to third embodiments.
That is, with respect to the stator 100 and the mover 200 of the actuators shown in the first to third embodiments, the detector unit 100b that detects the displacement in the linear motion direction and the rotational direction is arranged on the load side of the output shaft 201 and is counteracted. In contrast to the configuration in which the linear motion and rotational drive motor units 100a are respectively arranged on the load side, the fourth embodiment basically includes a linear scale 301 and a linear sensor head 302 on the load side of the output shaft 201. A motion detector unit 300, an X motor unit comprising an X armature winding 104 and an X field magnet unit 207 are provided, and a θ armature winding 103 and a θ field magnet unit 205 are provided on the non-load side of the output shaft 201. The difference is in the configuration in which the θ motor unit and the rotation detector unit 400 including the θ encoder 401 and the rotation sensor head 402 are arranged. Here, the linear motion detector unit 300 and the X motor unit disposed on the load side of the output shaft 201 are supported at both ends by the θX bearing unit 106 and disposed on the opposite load side of the output shaft 201. The portions of the θ motor unit and the rotation detector unit 400 are configured such that both ends thereof are supported by the θX bearing unit 106.
Further, regarding the arrangement of the motor unit, the configurations of the fourth embodiment and the third embodiment are the same in that the θ armature winding and the X armature winding are arranged concentrically in the longitudinal direction. However, the fourth embodiment is different from the third embodiment in that the anti-load side bracket 108 in which the θ armature winding 103 and the X armature winding 104 are provided between the second frame 102 and the first frame 101 is provided. It differs in that it is provided on both sides.
Further, regarding the arrangement of the magnetic field portion of the θ motor portion, the third embodiment (FIG. 5) is attached to the collar provided on the outer periphery of the ball spline located on the side opposite to the load side of the output shaft. The field portion of the θ motor portion of the fourth embodiment includes the outer periphery of the ball spline 106a positioned on the side opposite to the load 108 on the output shaft 201 and the outer periphery of the ball spline 106a positioned on the end bracket 109 side of the output shaft 201. It is different in that it is attached to a collar 206 provided between the two.
Further, regarding the arrangement of the rotation detector unit 400, the third embodiment (FIG. 5) has a configuration in which a θ encoder is attached to the ball spline on the load side of the output shaft via a collar and a rotation sensor head is attached to the first frame. On the other hand, in the fourth embodiment, as shown in FIG. 6, the θ encoder 401 constituting the rotation detector unit 400 is attached to the collar 206 provided on the non-load side of the output shaft 201 and rotated to the second frame 102. The difference is in the configuration in which the sensor head 402 is attached.
The operation of the fourth embodiment is basically the same as that of the first to third embodiments, and the description thereof is omitted.

  Therefore, in the fourth embodiment, a θ motor unit composed of a θ armature winding and a θ field portion, and an X motor portion composed of an X armature winding and an X field portion are concentrically arranged in series in the longitudinal direction. In addition to being arranged side by side, the magnetic field part of the X motor part is attached to the output shaft, and the θ field magnetic part is located on the outer periphery of the ball spline located on the non-load side bracket side of the output shaft and on the end bracket side of the output shaft Since it is configured to be attached to the collar provided between the outer periphery of the ball spline, the gap between the X armature winding and the X field portion, and the gap between the θ armature winding and the θ field portion must be close to each other. Since the magnetic gap length is shortened, the output can be increased. Although the length of the actuator in the longitudinal direction is somewhat longer, the output per unit volume can be increased because the output of the actuator is increased.

FIG. 7 is a side sectional view of an actuator showing a fifth embodiment.
The features of the actuator that performs linear motion rotation of the fifth embodiment are as follows.
In FIG. 7, in the stator 100 and the mover 200 of the actuator that performs linear motion rotation according to the fifth embodiment, the detector unit 100 b is disposed on the load side of the output shaft 201, and the motor unit 100 a is disposed on the non-load side. ing.
The motor unit 100a includes a cylindrical second frame 102 that also serves as an armature core on the stator 100 side, a θ armature winding 103 that generates a rotating magnetic field in the rotation direction, and an X electric machine that generates a traveling magnetic field in the linear motion direction. The child windings 104 are provided so as to overlap in a concentric manner. The second frame 102 is provided with a motor terminal (not shown) for supplying external power to the θ armature winding 103 and the X armature winding 104. On the other hand, on the side of the mover 200 of the motor unit 100a, a field unit 202 is provided on the output shaft 201 so as to be opposed to the inside of the X armature winding 104 via a magnetic gap. The details of the field portion of the mover are the same as in FIG. 2, and the details of the arrangement relationship between the armature winding and the permanent magnet are the same as in FIG.

The detector unit 100b includes a linear motion detector unit 300 that detects the displacement of the output shaft 201 in the linear motion direction, and a rotation detector unit 400 that detects the displacement of the output shaft 201 in the rotational direction. The points of the above configuration are basically different from the first to fourth embodiments described above.
More specifically, a bearing 106b is provided on the outer periphery of the output shaft 201, and a hollow cylindrical member 210 (corresponding to a scale holder) that moves freely on the inner periphery of the first frame 101 via the ball spline 106a. It is fixed to the outer ring 106b. The rotation detector unit 400 includes a θ encoder 401 attached to the outer periphery of the output shaft 201, and a rotation sensor head 402 provided on the inner periphery of the hollow cylindrical member 210 so as to face the θ encoder 401. The linear motion detector unit 300 includes an optical linear scale 301 provided on the outer periphery of the hollow cylindrical member 210 and an optical linear sensor head 302 attached to the inner periphery of the first frame 101. .

  Further, as described above, the support mechanism is arranged through the ball spline 106a arranged at both ends of the first frame 101 where the detector unit 100b is arranged, and the inner periphery of the ball spline 106a via the hollow cylindrical member 210. The bearing 106b constitutes the θX bearing portion 106, and the ball spline 106a and the bearing 106b constitute the θX bearing portion 106 on the end bracket 109 positioned on the opposite side of the second frame 102 where the motor portion 100a is disposed. Yes. That is, the outer ring of the bearing 106b of the θX bearing 106 positioned in the detector 100b is fixed to the inner periphery of the hollow cylindrical member 210 that moves along the ball spline 106a on the inner periphery of the first frame 101, and the other bearing. The inner ring 106b is fixed to the outer periphery of the output shaft 201, and rotates with the output shaft 201 with respect to the hollow cylindrical member 210.

Next, the operation will be described.
The actuator configured in this manner generates torque in the mover 200 by the action of a magnetic field created by a permanent magnet in the field portion by causing a current to flow through the θ armature winding 103, and the X armature winding By causing a current to flow through 104, a thrust is generated in the mover 200 by the action of a magnetic field generated by a permanent magnet in the field part, and a rotating operation and a linear motion operation can be performed.
When a current is supplied to only one θ armature winding 103, the hollow cylinder that faces the output shaft 201 in a state where the output shaft 201 is supported in a radial direction by the bearing 106b of the θX bearing 106 located in the detector unit 100b. It rotates relative to the shaped member 210. At that time, the θ encoder 401 fixed to the outer periphery of the output shaft 201 rotates simultaneously, and the rotation position of the output shaft is adjusted by the rotation sensor head 402 provided on the inner periphery of the hollow cylindrical member 210 so as to face the θ encoder 401. Detected.
Further, when a current is supplied only to the other X armature winding 104, the hollow cylindrical member 210 linearly moves while being supported in the axial direction by the ball spline 106a of the θX bearing 106 located in the detector unit 100b. The output shaft 201 supported in the radial direction by the hollow cylindrical member 210 also moves linearly at the same time. At that time, the linear scale 301 attached to the outer periphery of the hollow cylindrical member 210 is linearly moved simultaneously, and the linear sensor head 302 provided on the inner periphery of the first frame 101 so as to face the linear scale 301 is used to directly adjust the output shaft. A moving position is detected.
When current is supplied to both the θ armature winding 103 and the X armature winding 104, the output shaft 201 rotates and at the same time, the hollow cylindrical member 210 moves linearly, and rotation detection and linear motion detection are accurately performed. It can be carried out.

Accordingly, in the fifth embodiment, the motor unit can shorten the length in the longitudinal direction of the actuator by arranging the θ armature winding and the X armature winding concentrically so as to be shortened per unit volume. Output can be increased, and a high output actuator can be provided.
Further, the θX bearing part is composed of one ball spline and two bearings each, and the θX bearing part is arranged on both sides of the detector part, and the rotation detector part constituting the detector part; By arranging the linear motion detector portions concentrically and overlappingly, the backlash and eccentricity of the output shaft at the detector portion can be further eliminated as compared with the first to fourth embodiments. Straightness and rotational shake accuracy can be further improved. Since the straightness of the output shaft and the accuracy of rotational runout can be further improved, the straightness of the linear scale of the linear motion detector placed on the output shaft and the rotational runout accuracy of the θ encoder of the rotational detector can be improved. The position in the direction and the angle in the rotation direction can be detected with high accuracy.
Also, by arranging the end bracket on the opposite side of the motor part and supporting the output shaft via the θX bearing part, it becomes equivalent to the configuration in which the θX bearing part is arranged on both sides of the motor part. The backlash and eccentricity of the field part can be eliminated, and consequently the backlash and eccentricity of the output shaft can be eliminated, and the straightness of the output shaft and the accuracy of the rotational runout can be improved.

FIG. 8 is a side sectional view of an actuator showing a sixth embodiment.
The features of the actuator that performs linear motion rotation in the sixth embodiment are as follows.
In FIG. 8, in the stator 100 and the mover 200 of the actuator that performs linear motion rotation of the sixth embodiment, a motor unit 100a is arranged on the load side of the output shaft 201, and a detector unit 100b is arranged on the non-load side. ing.

The motor unit 100a includes a cylindrical first frame 101 that also serves as an armature core on the stator 100 side, a θ armature winding 103 that generates a rotating magnetic field in the rotation direction, and an X electric machine that generates a traveling magnetic field in the linear motion direction. The child windings 104 are provided so as to overlap in a concentric manner. The first frame 101 is provided with a motor terminal (not shown) for supplying external power to the θ armature winding 103 and the X armature winding 104. On the other hand, on the side of the mover 200 of the motor unit 100a, a field unit 202 is provided on the output shaft 201 so as to be opposed to the inside of the X armature winding 104 via a magnetic gap. The output shaft 201 is made of stainless steel, which is a nonmagnetic material.
As described above, the motor unit 100a can shorten the length in the longitudinal direction of the actuator by arranging the θ armature winding 103 and the X armature winding 104 in a concentric manner so that the output per unit volume can be reduced. Can be increased.

The detector unit 100b includes a linear motion detector unit 300 that detects displacement of the output shaft 201 in the linear motion direction, and a rotation detector unit 400 that detects displacement of the output shaft 201 in the rotational direction.
The linear motion detector unit 300 includes a cylindrical optical linear scale 301 fixed to the outer periphery of the output shaft 201 and an optical linear sensor head 302 fixed to the inner periphery of the second frame 102. . The rotation detector unit 400 includes a θ encoder 401 fixed to a ball spline 106a of a θX bearing unit 106, which will be described later, via a collar 403, and a rotation sensor head 402 fixed to the second frame 102. A permanent magnet is used for the θ encoder 401 constituting the rotation detector 400, and the rotation sensor head 402 is evenly arranged on the inner side of the second frame 102 so as to face the permanent magnet through a gap. Four magnetic detection elements such as MR elements and Hall elements are used to constitute a so-called magnetic encoder. The first frame 102 is provided with a detector terminal (not shown) that supplies power to the linear motion detector unit 300 and the rotation detector unit 400 from the outside and outputs detection signals of the position X and the angle θ. Yes.

  The support mechanism includes a load-side bracket 107 on the load side of the first frame 101 where the motor unit 100a is disposed, and an anti-load-side bracket 108 on the non-load side. The load side bracket 107 and the anti-load side bracket 108 are respectively provided with θX bearing portions 106 each composed of one ball spline 106a and two bearings 106b. An end cap 110 is provided on the opposite side of the second frame 102 where the detector unit 100b is disposed.

Next, the operation will be described.
The actuator configured in this manner is configured such that the load side of the output shaft 201 is formed by the ball splines 106a constituting the θX bearing portions 106 provided at two locations of the load side bracket 107 and the anti-load side bracket 108 of the first frame 101, respectively. Since the output shaft 201 and the ball spline 106a are supported so as to be able to rotate in the θ direction by bearings 106b provided at two locations on the same part as the ball spline 106a. The output shaft 201 on which the motor unit 100a is disposed is supported by the both ends with respect to the first frame 101 portion of the stator 100, and the rotation in the θ direction and the direct movement in the X direction can be freely moved. In addition, since the θ encoder 401 is provided outside the ball spline 106a located on the side opposite to the load 108 on the output shaft 201 via the collar 403, the length on the side opposite to the load on the output shaft 201 constituting the detector unit 100b. The axis can be shortened. A load (not shown) is provided at the tip of the output shaft end 201, and the load (not shown) can be freely moved in the θ direction and the X direction.

Accordingly, in the sixth embodiment, the length of the actuator in the longitudinal direction can be shortened by arranging the motor armature coil and the X armature coil in a concentric manner so that the length per unit volume can be reduced. The output can be increased and a high output actuator can be provided.
In addition, each θX bearing part is composed of one ball spline and two bearings each, and the θX bearing parts are arranged on both sides of the motor part, so that the backlash and eccentricity of the output shaft in the motor part is reduced. The straightness of the output shaft and the accuracy of rotational runout can be improved. Since the straightness of the output shaft and the accuracy of rotational runout can be improved, the straightness of the linear scale of the linear motion detector placed on the output shaft and the rotational shake accuracy of the θ encoder of the rotational detector can be improved. And the angle in the rotation direction can be detected with high accuracy.
In addition to the configuration in which the motor unit is arranged on the load side of the output shaft and the detector unit is arranged on the anti-load side, the rotation detector unit is constructed on the ball spline part of the θX bearing unit in the anti-load side bracket Since the θ encoder is provided, the length of the output shaft constituting the detector section on the non-load side can be shortened, and the θ encoder can be rotatably supported by the bearing of the anti-load side bracket. Therefore, it is considered that the radial gap of the bearing is an average gap fluctuation and a magnetic gap fluctuation of several μm. In the case of a magnetic encoder using, for example, a permanent magnet for the θ encoder and a magnetic detection element such as an MR element or a Hall element for the rotation sensor head facing the θ encoder, the detection error of the magnetic encoder can be reduced. it can.

FIG. 9 is a side sectional view of an actuator showing a seventh embodiment.
The features of the actuator that performs linear motion rotation according to the seventh embodiment will be described below as to differences from the sixth embodiment.
That is, the actuator shown in the sixth embodiment is different from the actuator shown in the seventh embodiment in that the linear motion and rotational drive motor portions are concentrically arranged on the first frame side. Of the linear motion and rotational drive motor portions 100a disposed on the one frame 101 side, the field portion and the armature portion are arranged separately in concentric circles. More specifically, a bearing 106b is provided on the outer periphery of the output shaft 201, and a hollow cylindrical member 210 that moves freely on the inner periphery of the first frame 101 via the ball spline 106a is fixed to the outer ring of the bearing 106b. Has been provided. The θ motor unit includes a θ field magnet portion 205 attached to the outer periphery of the output shaft 201 and a θ armature winding 103 provided on the inner periphery of the hollow cylindrical member 210 so as to face the θ field magnet portion 205. Has been. The X motor unit includes an X field magnet part 207 provided on the outer periphery of the hollow cylindrical member 210 and an X armature winding 104 attached to the inner periphery of the first frame 101.
Further, in the configuration in which the sixth embodiment is arranged with a detector unit composed of a rotation detector unit and a linear motion detector unit for detecting displacements in the rotational direction and the linear motion direction on the second frame side, respectively. In the seventh embodiment, a linear motion rotation detector unit 500 including a linear motion rotation scale 501 and a linear motion rotation sensor head 502 is provided.

Next, the operation will be described.
The actuator configured as described above generates torque in the mover 200 by the action of a magnetic field generated by the permanent magnet of the θ field magnet portion 205 by passing a current through the θ armature winding 103, and the X armature By causing a current to flow through the winding 104, a thrust is generated in the mover 200 due to the action of the magnetic field generated by the permanent magnet of the X field magnet portion 207, and a rotating operation and a linear motion operation can be performed.
When a current is supplied only to one θ armature winding 103, the hollow cylindrical member 210 rotates while the output shaft 201 is supported in the radial direction by the bearing 106b of the θX bearing 106 positioned in the motor unit 100a. At that time, the linear motion rotation scale 501 fixed to the outer periphery of the output shaft 201 rotates at the same time, and the linear motion rotation sensor head 502 attached to the second frame 102 facing the linear motion rotation scale 501 causes the output shaft 201 of the output shaft 201 to rotate. The rotational position is detected.
Further, when a current is supplied only to the other X armature winding 104, the hollow cylindrical member 210 linearly moves while being supported in the axial direction by the ball spline 106a of the θX bearing 106 located in the motor unit 100a, The output shaft 201 supported in the radial direction by the hollow cylindrical member 210 also moves linearly at the same time. At that time, the linear motion rotary scale 501 attached to the outer periphery of the hollow cylindrical member 210 simultaneously moves linearly, and the linear motion sensor head 502 attached to the second frame 102 provided on the inner periphery of the output shaft 201 outputs the output shaft. The linear movement position 201 is detected.

Therefore, in the seventh embodiment, the linear motion and the armature portion in the motor unit 100a for linear motion and rotational drive disposed on the first frame 101 side are individually superimposed on each other in a concentric manner. Since the length of the actuator in the longitudinal direction can be shortened, the output per unit volume can be increased, and a high output actuator can be provided.
Further, each θX bearing portion is composed of one ball spline and two bearings, and the θX bearing portions are arranged on both sides of the motor portion, and the field portion and the armature that constitute the θ motor portion. And the field part and armature part which constitute the motor part and the X motor part are arranged separately and concentrically, so that the output shaft at the detector part is more eccentric and eccentric compared to the sixth embodiment. Thus, the straightness of the output shaft and the accuracy of the rotational runout can be further improved. Since the straightness of the output shaft and the accuracy of rotational runout can be further improved, the straightness of the linear scale of the linear motion detector placed on the output shaft and the rotational runout accuracy of the θ encoder of the rotational detector can be improved. The position in the direction and the angle in the rotation direction can be detected with high accuracy.
In addition, by arranging the end bracket on the non-load side of the detector unit and supporting the output shaft via the θX bearing unit, it is equivalent to the configuration in which the θX bearing unit is arranged on both sides of the detector unit. Thus, the backlash and eccentricity of the linear rotation scale can be eliminated, and consequently the backlash and eccentricity of the output shaft can be eliminated, and the straightness of the output shaft 201 and the accuracy of the rotational runout can be improved.

FIG. 10 is a side sectional view of the actuator showing the eighth embodiment.
The features of the actuator that performs linear motion rotation according to the eighth embodiment will be described as follows.
That is, in the detector section 100b of the actuator shown in the tenth embodiment, a hollow cylinder that is provided with a bearing 106b on the outer periphery of the output shaft 201 and moves freely on the inner periphery of the first frame 101 via the ball spline 106a. A member 210 (corresponding to a scale holder) is provided fixed to the outer ring of the bearing 106b. In such a configuration, the linear motion detector unit 300 includes an optical linear scale 301 provided on the outer periphery of the hollow cylindrical member 210 and an optical linear sensor head 302 attached to the inner periphery of the first frame 101. It is configured.

Next, the operation will be described.
The actuator configured in this manner generates torque in the mover 200 by the action of a magnetic field created by a permanent magnet in the field portion by causing a current to flow through the θ armature winding 103, and the X armature winding By causing a current to flow through 104, a thrust is generated in the mover 200 by the action of a magnetic field generated by a permanent magnet in the field part, and a rotating operation and a linear motion operation can be performed.
When current is supplied only to one of the θ armature windings 103, the output shaft 201 is supported in the radial direction by the bearing 106b of the θX bearing 106 located in the detector unit 100b, and the hollow facing the output shaft 201 It rotates relative to the cylindrical member 210. At this time, the hollow cylindrical member 210 does not rotate.
Further, when the current was supplied only to the other X armature winding 104, the output shaft 201 was supported in the axial direction by the ball spline 106a of the θX bearing 106 in which the hollow cylindrical member 210 was positioned in the detector unit 100b. At this time, the hollow cylindrical member 210 having the linear scale 301 attached to the outer periphery also moves linearly at the same time. The linear sensor head 302 provided on the inner periphery of the first frame 101 is opposed to the linear scale 301. Thus, the linear motion position of the output shaft is detected.
When current is supplied to both the θ armature winding 103 and the X armature winding 104, the output shaft 201 rotates and linearly moves at the same time, and rotation detection and linear motion detection can be accurately performed.

  Therefore, in the eighth embodiment, since the linear scale of the linear motion detector portion constituting the detector portion is attached to the hollow cylindrical member and directly rotated via the ball spline, the rotation is stopped. Compared with the embodiment, the backlash and eccentricity of the output shaft at the detector section can be eliminated, and the straightness of the output shaft and the accuracy of the runout can be further improved.

In the present embodiment, the optical linear sensor is used for detecting the linear movement displacement in the X direction. However, this is only an example for explaining the embodiment. For example, a sensor for detecting a magnetic change is used. May be. In addition, the magnetic sensor is used to detect the angle of rotation in the θ direction. However, this is merely an example for explaining the embodiment, and for example, a sensor that detects light reflection (or transmission) may be used. It is natural.
In addition, the ball spline and the ball bearing are used as the smooth support mechanism, but a rotary ball spline integrated with the ball spline may be used. Moreover, it is possible to change according to the required precision of a support part, and a slide bearing, a fluid bearing, etc. may be used.
In addition, the actuator described in the present embodiment realizes the operation in the linear movement direction and the rotation direction while narrowing the width direction, and is suitable for use in which a plurality of actuators are connected in the width direction or the depth direction. It is. In that case, it is considered that a plurality of actuators are coupled in the width direction or the depth direction so that the linear scale and the linear sensor for detecting the position in the linear motion direction are located on the front surface. It is considered that the interval in the width direction of the output shaft can be narrowed by connecting a plurality of actuators in the width direction or the depth direction in such a positional relationship.

  The present invention can provide a linear motion rotary actuator that precisely performs two operations of rotation and linear motion with one actuator. Therefore, the present invention can be applied to uses such as a mounter head of a chip mounter device and inspection heads of various inspection devices that require two-degree-of-freedom operation of linear motion and rotation.

100 Stator 100a Motor portion 100b Detector portion 101 First frame 102 Second frame 103, 103a θ armature winding, saddle coil 104, 104a X armature winding, ring coil 106 θX bearing portion 106a Ball spline 106b Bearing 106c Bearing 107 Load side bracket 108 Anti-load side bracket 109 End bracket 110 End cap 200 Movable element 201 Output shaft 202 Field part 203 Field yoke 204 Permanent magnet 204a, 204b Block magnet 205 θ field part 206 Collar 207 X field Magnetic part 210 Hollow cylindrical member 300 Linear motion detector part 301 Linear scale 302 Linear sensor head 400 Rotation detector part (magnetic encoder)
401 θ encoder (permanent magnet)
402 Rotation sensor head (magnetic detection element)
403 color 500 linear motion rotation detector unit 501 linear motion rotation scale 502 linear motion rotation sensor head

Claims (4)

A support mechanism that is arranged at a plurality of locations in the longitudinal direction of the output shaft so as to be concentric inside the frame, and supports the linear movement direction and the rotation direction of the output shaft;
A motor unit that is concentrically disposed between the support mechanisms in the longitudinal direction of the output shaft, and drives the output shaft in a linear motion direction and a rotational direction;
A detector unit including a first detection unit that detects an angle of the output shaft in a rotation direction and a second detection unit that detects a displacement of the output shaft in a linear motion direction;
With
The motor unit includes a permanent magnet as a field, and an armature that is disposed to face the field through a magnetic gap and generates a moving magnetic field,
The armature of the motor unit is disposed so as to be concentrically overlapped with a first armature winding that drives the output shaft in a rotation direction, and the first armature winding. A second armature winding that drives in a linear motion direction,
The support mechanism includes a first bearing that rotatably supports the output shaft, and a second bearing that supports the output shaft so as to freely move.
The second bearing is connected to a collar protruding from the outer cylinder end of the second bearing along the longitudinal direction of the output shaft,
The detection object of the first detection unit is attached to the collar protruding from the outer cylinder end of the second bearing , and the other detector is attached to the frame. The support mechanism is
It said frame said first bearing for rotatably supporting is attached to the output shaft, further comprising a second bearing supporting the output shaft linearly movable in the inner peripheral surface of the first bearing The actuator according to claim 1.   The actuator according to claim 1, wherein the detector unit is disposed on a load side of the output shaft, and the motor unit is disposed on a non-load side of the output shaft.   The actuator according to claim 1, wherein the output shaft is made of a nonmagnetic material.

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