JP5218493B2 - 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 present invention relates to an actuator, and includes a rotary drive unit having a first movable element provided rotatably and a first stator arranged concentrically on the outer periphery of the first movable element via a magnetic gap. A linear motion drive unit having a second mover provided so as to be linearly movable along the axial direction and a second stator disposed concentrically on the outer periphery of the second mover via a magnetic gap; The rotation drive unit and the linear motion drive unit are arranged in parallel to support the first movable element so as to be capable of linear movement, and to allow the rotation of the first movable element via the arm. The first mover is connected to the second mover, and the first mover is linearly rotated by linearly moving the first mover according to the linear movement of the second mover. Yes.
The present invention, in the actuator, and characterized by storing the linear drive unit and the rotary drive unit in the same case.
The present invention may be straight in the actuator, to both ends of said linear drive unit and the rotary drive unit, an output shaft which constitutes each mover of the drive unit so that each of the driving portion of the stator and concentrically A support mechanism for supporting the movement direction or the rotation direction is provided, and further includes a first detector for detecting an angle in the rotation direction of the output shaft of each of the drive units, and a displacement in the linear movement direction of the output shaft. A detector unit including a second detector for detection is provided.
The present invention, in the actuator, the support mechanism of the rotary drive unit, with a first bearing for rotatably supporting the output shaft to the frame is attached, via a collar on the inner peripheral surface of the first bearing A second bearing for supporting the output shaft so as to be linearly movable; and the second detector for detecting a displacement in the linear motion direction is provided on a non-load side of the rotational drive unit and The detector is provided with a hollow cylindrical member attached to an outer ring of a third bearing that rotatably supports the non-load side of the output shaft of the rotation drive unit in the radial direction. The hollow cylindrical member is connected to an output shaft of the linear motion drive unit by an arm.
The present invention, in the actuator, the support mechanism of the rotary drive unit, with a first bearing for rotatably supporting the output shaft to the frame is attached, via a collar on the inner peripheral surface of the first bearing A second bearing for supporting the output shaft so as to be linearly movable; the detector unit is provided between a support mechanism on a load side and an anti-load side of the rotation drive unit; are composed of, the the end of the output shaft of the rotary drive unit, provided with a third bearing for the shaft supporting rotatably in the radial direction, and the arms attached to the outer ring of the third bearing linear It is characterized in that it is linearly moved and rotated by connecting to the output shaft of the dynamic drive unit.
The present invention, in the actuator, the rotary drive and the linear drive unit comprises a field having a permanent magnet or core teeth to field, it is oppositely arranged with the field magnet and the magnetic air gap And an armature that generates a moving magnetic field.
The present invention, in the actuator, the field part of the motor portion of the rotary drive unit is characterized in that attached to the output shaft to the color provided in the second bearing for linearly movable supporting .
The present invention, in the actuator, both of the field part of the motor section of the said rotary drive unit and the object to be detected in the first detector, the second bearing supporting the output shaft linearly movable in It is characterized by being attached to the collar provided.
The present invention, in the actuator, the first detector for detecting the angle of rotation direction is composed of the detector and the object to be detected, the detected body supports the output shaft linearly movable in the It is characterized by being attached to a collar provided in the second bearing.
The present invention, in the actuator, the detector unit is characterized in that the at first the detector formed by integrating the functions of the second detector.
The present invention, in the actuator, is characterized by configuring the output shaft in a non-magnetic 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 Side sectional view of an actuator showing a second embodiment Side sectional view of an actuator showing a third 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 is composed of a rotation drive unit 200 and a linear motion drive unit 300, and each drive unit has an intermediate frame 102 in the center inside a motor frame 101. Are arranged in parallel in the left-right direction in the figure. Here, the rotation drive unit and the linear drive unit are configured to be stored in the same case (not shown). .
The actuator is installed such that the θ direction is the rotational direction so that the illustrated X direction is downward in the vertical direction.

First, the rotation drive unit 200 includes a θ-axis motor unit 202 on the load side, a rotation detector unit 208 that detects displacement in the rotation direction of the output shaft 201 on the non-load side, and a displacement in the linear motion direction of the output shaft 201. A linear motion detector unit 209 for detecting the above is disposed.
The θ-axis motor unit 202 generates a rotating magnetic field in the rotation direction and is disposed concentrically facing the θ armature winding 206 constituting the stator 200b and the θ armature winding 206 via a magnetic gap. A field portion 203 made of a permanent magnet 205 constituting the mover 200a is provided.
On the load side and the opposite load side of the θ-axis motor unit 202, a θX bearing unit 207 configured by one ball spline 207a and two bearings 207b is disposed. A collar 204 is attached between the load-side and anti-load-side ball splines 207 a, and the θ-axis motor unit 202 is fixed to the outer periphery of the collar 204. Under this state, the output shaft 201 is moved by the θX bearing unit 207. The magnetic field portion 203 constituting the θ-axis motor portion 202 is supported so as to move linearly in the longitudinal direction, and is rotated in the radial direction by a bearing 207b fixed to the outer periphery of the ball spline 207a via the collar 204. It is the structure which supports to.

The rotation detector unit 208 is provided in the vicinity of the θX bearing unit 207 located on the anti-load side of the θ-axis motor unit 202 (the anti-load side of the rotation drive unit in the figure), and is fixed to the outer periphery of the collar 204. Θ encoder 208a and a rotation sensor head 208b fixed to the motor frame 101.
Further, the linear motion detector unit 209 includes a linear scale 209a attached to a hollow cylindrical member 211 rotatably supported on the output shaft 201 via a bearing 207c, and a linear sensor head fixed to the inside of the motor frame 101. 209b .
The motor frame 101 is provided with a motor terminal (not shown) for supplying external power to the θ armature winding 206 and the X armature winding 306, and the motor frame 101 has a linear motion detector unit 209 and the like. A detector terminal (not shown) that supplies external power to the rotation detector unit 208 and outputs a detection signal of the position X and the angle θ is provided.
The output shaft 201 is made of stainless steel, which is a nonmagnetic material.

Next, the linear motion drive unit 300 is basically provided with an X-axis motor unit 302 and ball splines 307 that are provided at both ends of the X-axis motor unit 302 and support the output shaft 301.
The X-axis motor unit 302 generates a traveling magnetic field in the linear motion direction and is concentrically opposed to the X armature winding 306 constituting the stator 300b and the X armature winding 306 via a magnetic gap. In addition, a field portion 303 made of a permanent magnet attached to the output shaft 301 constituting the mover 300a is provided.
In this way, the ball spline 307a is arranged on the load side and the non-load side of the X-axis motor unit 302, and the output shaft 301 on which the X-axis motor unit 302 is arranged is supported at both ends by the ball spline 307a. However, it can move freely in the linear motion direction.

  Furthermore, the load side and the anti-load side of the output shaft 201 provided in the rotation drive unit 200 are each supported by an inner ring of a bearing 207b attached to a ball spline 207a outside the output shaft 201. The outer ring of the bearing 207 c supported on the load side of the output shaft 201 is connected to one end of an arm 309 provided on the load side of the output shaft 201 of the linear motion drive unit 300. The outer ring of the bearing 207c supported on the opposite side of the output shaft 201 by the load is held by a hollow cylindrical member 211 (corresponding to a scale holder). It is connected to one end of an arm 308 provided on the load side.

Next, the operation will be described.
In such a configuration, a current is supplied to the θ armature winding 206 of the rotary drive unit 200 to generate torque on the output shaft 201 by the action of the magnetic field created by the permanent magnet 205 of the field magnet unit 203, and linear motion By supplying a current to the X armature winding 306 of the drive unit 300, a thrust is generated on the output shaft 301 by the action of the magnetic field created by the permanent magnet of the field magnet unit 303.
When an electric current is supplied only to one rotary drive unit 200, the inner ring of the bearing 207b is fixed to the outer periphery of the ball spline 207a of the θX bearing provided with the output shaft 201 on the load side and the non-load side. The output shaft 201 provided with 203 rotates relative to the θ armature winding 206, and the θ encoder 208a fixed to the outside of the ball spline 207a rotates simultaneously. At this time, the linear scale 209a attached to the outer ring of the bearing 207c on the non-load side of the output shaft 201 via the hollow cylindrical member 211 is in a stopped state, but is disposed to face one of the θ encoders 208a. The rotation sensor head 208b detects the rotation operation of the output shaft 201 in the θ direction.
When supplying current only to the other linear motion drive unit 300, the output shaft 301 moves linearly in the ball spline 307 in the axial direction, and the arms 308 and 309 are connected to the load side and the anti-load side of the output shaft 301. The output shaft 201 of the rotational drive unit 200 connected via the linear movement of the ball spline 207a of the θX bearing of the rotational drive unit 200 moves linearly. At this time, in the linear motion detector unit 209, the linear sensor head 209b disposed to face the linear scale 209a detects the linear motion of the output shaft 201 in the X direction.
When current is supplied to both the rotation drive unit 200 and the linear motion drive unit 300, the output shaft 201 rotates at the same time as the output shaft 201 rotates, so that rotation detection and linear motion detection can be accurately performed.

Therefore, the actuator that performs the linear motion rotation according to the first embodiment is configured such that the rotation drive unit and the linear motion drive unit are arranged in parallel, and the load side and the anti-load side of the output shaft of the linear motion drive unit are connected to the ball spline. The output shaft on the load side and the opposite load side of the θ-axis motor part is supported by a θX bearing part composed of one ball spline and two bearings, and the output shaft of the linear motion drive part From the point that the arm provided at the end of the load side and the opposite side of the load is connected to the load side and the end of the load side of the output shaft of the rotary drive unit respectively, It is considered that the output per unit volume can be increased and the size can be reduced.
When current is supplied to the θ armature winding and the X armature winding, heat is generated in the rotary drive unit and the linear drive unit, respectively. Since the output shaft provided for each of the rotary drive unit and the linear drive unit is individually shortened, even if it is thermally expanded due to the heat generated from each armature winding, its thermal deformation is minimized. The position error in the linear motion direction of the output shaft and the angle error in the rotation direction can be reduced.
In addition, each 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 θ motor part and the rotation detector part arranged on the load side of the output shaft. As a result, it is possible to eliminate the play and eccentricity of the output shaft in the rotation detector section, and it is possible to improve the straightness of the output shaft and the accuracy of the runout. 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 particular, a collar is attached to the ball spline on the load side of the output shaft, a permanent magnet is attached to the cylindrical surface of the collar, and four pieces are arranged evenly on the circumference so as to face the permanent magnet through a gap. A magnetic detection element such as an MR element or a Hall element is arranged to constitute a so-called magnetic encoder. As described above, the permanent magnet is rotatably supported by the bearings on the load side and the non-load side of the output shaft, resulting in an average gap fluctuation of the radial gap of the bearing, and a fluctuation of the magnetic gap of several μm. Therefore, it is considered that the detection error of the magnetic encoder can be reduced.
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.

FIG. 2 is a side sectional view of an actuator showing a second embodiment. In addition, description is abbreviate | omitted about the same component as 1st Embodiment of 2nd Embodiment.
The actuator that performs linear motion rotation of the second embodiment is different from the first embodiment as follows.
In other words, the detector section of the actuator shown in the second embodiment basically comprises a linear motion rotation detector section 210 that integrates the functions of the linear motion detector section and the rotation detector section of the first embodiment. It is a point. A so-called linear rotation detector 210 is provided between the load-side and anti-load-side support mechanisms (ball spline 207a and bearing 207b) of the rotation drive unit, and is a cylindrical shape fixed to the outer periphery of the output shaft 201. The linear motion rotation scale 210a and the linear motion rotation sensor head 210b fixed to the inner periphery of the motor frame 101 are configured to detect displacement in the linear motion direction and the rotational direction.
In the rotation driving unit 200, the field unit 203 of the θ-axis motor unit 202 is attached to the outside of the collar 204 provided on the ball spline 207a on the non-load side of the output shaft 201, and the other θ armature winding. The wire 206 is attached to the motor frame 101 so as to be concentric with the field portion 203 .
Note that the configuration of the linear motion drive unit 300 of the second embodiment is basically the same as that of the first embodiment, and a description thereof will be omitted.

Next, the operation will be described.
In such a configuration, a current is supplied to the θ armature winding 206 of the rotary drive unit 200 to generate torque on the output shaft 201 by the action of the magnetic field created by the permanent magnet 205 of the field magnet unit 203, and linear motion By supplying a current to the X armature winding 306 of the drive unit 300, a thrust is generated on the output shaft 301 by the action of the magnetic field created by the permanent magnet of the field magnet unit 303.
When the current is supplied only to one rotary drive unit 200, the output shaft 201 is supported in the radial direction by the bearing 207b provided on the ball spline 207a of the θX bearing on the load side and the non-load side . Is rotated with respect to the θ armature winding 206. At this time, the linear motion rotation scale 210a of the linear motion rotation detector unit 210 fixed to the output shaft 201 rotates at the same time, and the linear motion rotation sensor head 210b arranged to face the linear motion rotation scale 210a becomes the output shaft 201. Rotating motion in the θ direction is detected.
Further, when the current is supplied only to the other linear motion drive unit 300, the output shaft 301 moves linearly in the ball spline 307 in the axial direction, and the arm 308, The output shaft 201 of the rotation drive unit 200 connected via the 309 linearly moves inside the ball spline 207 a of the θX bearing of the rotation drive unit 200. At this time, in the linear motion detector unit 209, the linear sensor head 209b disposed to face the linear scale 209a detects the linear motion of the output shaft 201 in the X direction.
When current is supplied to both the rotation drive unit 200 and the linear motion drive unit 300, the output shaft 201 rotates at the same time as the output shaft 201 rotates, so that rotation detection and linear motion detection can be accurately performed.

Therefore, in the second embodiment, a cylindrical linear motion rotation scale fixed on the outer periphery of the output shaft between the load side and the anti-load side of the output shaft, and a linear motion fixed on the inner periphery of the first frame. By providing a linear motion rotation detector unit consisting of a rotation sensor head and integrating 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. In addition to the reduction in size, it is possible to eliminate backlash and eccentricity of the output shaft in the detector section by further downsizing. 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.
Also, since the field part of the θ-axis motor is mounted outside the collar provided on the ball spline on the non-load side of the output shaft, the gap between the θ armature winding and the θ field part should be close Since the magnetic gap length is shortened, the output can be increased. The length of the θ-axis motor in the longitudinal direction is shortened, and the size can be reduced.

FIG. 3 is a sectional side 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 actuator that performs linear motion rotation of the third embodiment is different from the second embodiment as follows.
That is, the actuator detector section shown in the third embodiment basically includes the rotation detector section 208 and the linear motion detector section 209 separately. Among these, the θ encoder 208a constituting the rotation detector unit 208 is attached to the outside of the collar 212 provided on the ball spline 207a on the load side of the output shaft 201, and the other rotation sensor head 208b is attached to the motor frame 101. It is attached to detect the displacement in the rotational direction. The cylindrical linear scale 209a constituting the linear motion detector unit 209 is fixed between the load side and the non-load side of the output shaft 201, and the other linear sensor head 209b is attached to the motor frame 101. Yes.
In the rotation driving unit 200, the field unit 203 of the θ-axis motor unit 202 is attached to the outside of the collar 204 provided on the ball spline 207a on the non-load side of the output shaft 201, and the other θ armature winding. The wire 206 is attached to the motor frame 101 so as to be concentric with the field portion 203 .
Note that the configuration of the linear motion drive unit 300 of the third embodiment is basically the same as that of the second embodiment, and a description thereof will be omitted.
Further, the operation of the third embodiment is basically the same as that of the second embodiment, and the description thereof is omitted.

Therefore, in the third embodiment, the θ encoder constituting the rotation detector is attached to the collar provided on the ball spline on the load side of the output shaft, the rotation sensor head is attached to the motor frame, and the linear motion detection The linear scale that constitutes the detector section is fixed between the load side and the anti-load side of the output shaft, and the linear sensor head is attached to the motor frame. Can be eliminated. 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.
Also, the field part of the θ-axis motor is attached to the outside of the collar provided on the ball spline on the opposite side of the output shaft, and the θ armature winding is attached to the motor frame so as to be concentric with the θ field part. Since it is configured, the magnetic gap length is shortened by the close proximity of the gap between the θ armature winding and the θ field part, so that the output can be increased. The length of the θ-axis motor in the longitudinal direction is shortened, and the size can be reduced.

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.

  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 101 Motor frame 102 Intermediate frame 103 End bracket 200 Rotation drive part 200a Movable element 200b Stator 201 Output shaft 202 θ-axis motor part 203 Field part 204 Color 205 Permanent magnet 206 θ Armature winding 207 θX bearing part 207a Ball spline 207b Bearing 207c Bearing 208 Rotation detector section 208a θ encoder 208b Rotation sensor head 209 Linear motion detector section 209a Linear scale 209b Linear sensor head 210 Linear motion rotation detector section 210a Linear motion rotation scale 210b Linear motion rotation sensor head 211 , 212 hollow cylindrical member 300 linear motion drive unit 300a mover 300b stator 301 output shaft 302 X-axis motor unit 303 field unit 306 θ armature winding 307 ball spline 308 arm 3 09 Arm

Claims (11)

A rotation drive unit having a first movable element provided rotatably and a first stator arranged concentrically on the outer periphery of the first movable element via a magnetic gap;
A linear motion drive unit having a second movable element provided so as to be linearly movable along the axial direction and a second stator arranged concentrically on the outer periphery of the second movable element via a magnetic gap;
The rotation drive unit and the linear motion drive unit are arranged in parallel to support the first movable element so as to be linearly movable, and to allow the first movable element to rotate via the arm while allowing the first movable element to rotate. One movable element is connected to the second movable element, and the first movable element is linearly rotated by linearly moving the first movable element in accordance with the linear movement of the second movable element. Actuator.   The actuator according to claim 1, wherein the rotary drive unit and the linear motion drive unit are stored in the same case. The rotational drive unit and the linear motion drive unit support the linear motion direction or the rotational direction at both ends of the output shaft constituting the mover of each drive unit so as to be concentric with the stator of each drive unit. A support mechanism is provided,
A first detector, a detector unit and a second detector for detecting the linear direction of displacement of the output shaft is further provided for detecting the angle of the direction of rotation of the output shaft of each of the drive unit The actuator according to claim 1 or 2, wherein The support mechanism of the rotational drive unit is
A first bearing for rotatably supporting the output shaft is attached to the frame, and a second bearing for supporting the output shaft in a directly movable manner via a collar is provided on the inner peripheral surface of the first bearing. And
The second detector for detecting the displacement in the linear motion direction is provided on the opposite load side of the rotational drive unit and is composed of a detected object and a detector,
The object to be detected is provided in a hollow cylindrical member attached to an outer ring of a third bearing that rotatably supports a non-load side of the output shaft of the rotation drive unit in a radial direction.
4. The actuator according to claim 3, wherein the hollow cylindrical member is connected to an output shaft of the linear drive unit by an arm. The support mechanism of the rotational drive unit is
A first bearing for rotatably supporting the output shaft is attached to the frame, and a second bearing for supporting the output shaft in a directly movable manner via a collar is provided on the inner peripheral surface of the first bearing. And
The detector unit is provided between a support mechanism on the load side and the anti-load side of the rotation drive unit, and includes a detection object and a detector.
Wherein the end portion of the output shaft of the rotary drive unit, provided with a third bearing for the shaft supporting rotatably radially output shaft of said third of said arms attached to the outer ring of the bearing linear drive unit 4. The actuator according to claim 3, wherein the actuator is linearly moved and rotated by being connected to the actuator.   The rotary drive unit and the linear motion drive unit are arranged so as to face a field having a permanent magnet or iron core teeth as a field, and the field through a magnetic gap, and generate a moving magnetic field The actuator according to claim 1, wherein the actuator is provided. Field part of the motor portion of the rotary drive unit, No placement claim 4 or 5 SL, characterized in that the output shaft is attached to the color provided in the second bearing for linearly movable supporting Actuator. Both the detected object of the first detector and the field part of the motor part in the rotation drive part are attached to a collar provided in the second bearing that supports the output shaft so as to be movable linearly. The actuator according to claim 4 or 5, wherein The first detector for detecting an angle in the rotation direction is composed of a detected body and a detector, and the detected body is provided in the second bearing that supports the output shaft so as to be capable of linear movement. 6. The actuator according to claim 4 , wherein the actuator is attached to a collar. The detector unit, an actuator according to claim 3, characterized in that is formed by integrating the functions of the first detector and the second detector.   The actuator according to claim 3, wherein the output shaft is made of a nonmagnetic material.

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