JP2016119780A - Actuator, machine tool, measuring apparatus, semiconductor manufacturing apparatus, and flat display manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator which prevents foreign objects from entering thereinto and prevents dust emission occurring therein from flowing out to an exterior part in a more secure manner.SOLUTION: An actuator 1 includes: a seal part 217 where an outer cylinder part 112 formed in a rotor housing 10 and an inner cylinder part 211 formed in a stator housing 20 overlap with each other in a radial direction through a first gap 218; and an exhaust hole 214 for suctioning/exhausting air in an interior space enclosed by the rotor housing 10 and the stator housing 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an actuator, a machine tool, a measuring apparatus, a semiconductor manufacturing apparatus, and a flat display manufacturing apparatus.

  For example, Patent Document 1 describes an actuator that can convert a rotary motion into a linear motion with a single motor having two rotors, and can transmit the rotary motion and the linear motion individually or both. The actuator described in Patent Document 1 can be reduced in size and improved in reliability, and can contribute to space saving and cost reduction.

  High reliability is required for actuators used in machine tools, measuring devices, semiconductor manufacturing devices, and flat panel display manufacturing devices. Further, in the manufacture of semiconductors, flat panel displays and the like, a manufacturing process in a clean environment is required in order to avoid dust contamination in the product. In order to ensure high reliability, an actuator used in such a clean environment must prevent foreign matter from entering the actuator and prevent dust generated inside the actuator from flowing out. is there.

  For example, in Patent Document 2, by sucking air from an air chamber between two flange portions, air is sucked from a gap between the flange portion and the operating shaft, and dust from a non-clean environment is contained in the clean environment. A sealing device is described which prevents the intrusion.

JP 2013-230076 A JP 09-29682 A

  The sealing device described in Patent Document 2 sucks air from both the gap between the clean environment side flange portion and the operating shaft and the gap between the non-clean environment side flange portion and the operating shaft. It is conceivable that pressure distribution is generated in the air chamber. Further, when there is a pressure difference between the clean environment side and the non-clean environment side, air may leak from the non-clean environment side to the clean environment side, which may contaminate the clean environment.

  The present invention has been made in view of the above, and provides an actuator that can prevent foreign matter from entering the interior and more reliably prevent dust generated inside from flowing out to the outside. With the goal.

  In order to solve the above-described problems and achieve the object, an actuator is provided with a stator including an exciting coil and a stator core, a stator housing that fixes the stator, and a radially inner side of the stator, and A first rotor that rotates relative to the first rotor; a rod-shaped member that is disposed at the center of rotation of the first rotor; a screw shaft that has a thread groove formed on at least a part of its surface; and the first rotor, A nut threadedly engaged with a thread groove of the screw shaft, which moves the screw shaft in a linear motion direction that is a direction parallel to the rotation center of the first rotor; and a radially outer side of the stator; A second rotor that rotates relative to the second rotor, and a rotor housing that rotates together with the second rotor, wherein the rotor housing rotates the second rotor. A substantially disk-shaped plate portion disposed on one end side of the screw shaft in the linear motion direction with the center as an axis, and extending in the linear motion direction from a radially outer end portion of the plate portion, the second An outer cylinder portion formed on the radially outer side of the rotor, and the stator housing is disposed on the other end side of the screw shaft in the linear direction with the rotation center of the second rotor as an axis. A substantially disk-shaped housing base portion, and a radially inner end of the outer base portion extending in a linear motion direction from a radially outer end portion of the housing base portion, and having a first gap therebetween, the outer case An inner cylindrical portion that forms a seal portion that overlaps the portion in the radial direction, and an exhaust hole that is formed in the housing base portion and that sucks and exhausts the air enclosed by the rotor housing and the stator housing. Have.

  With the above configuration, by connecting the suction / exhaust device to the exhaust hole formed in the housing base portion and operating the suction / exhaust device, the air inside the actuator is uniformly sucked from the throttle portion. Accordingly, it is possible to prevent foreign matter from entering the inside of the actuator and reliably prevent dust generated inside the actuator from flowing out to the outside.

  As a desirable mode, the stator housing includes a substantially annular groove formed on a surface of the housing base portion on the inner cylinder portion side with the rotation center of the second rotor as an axis, and an inner diameter of the groove housing portion. It is a substantially annular member having an outer diameter smaller than the inner diameter and larger than the outer diameter of the groove portion and covering the groove portion in the linear motion direction, and is located on the inner cylinder portion side of the housing base portion with a second gap therebetween And an annular member that forms a constricted portion that overlaps in the linear motion direction, and the exhaust hole extends in one radial direction from a wall surface on the outer diameter side of the groove portion, and the housing base portion It is preferable to be formed so as to pass through.

  With the above configuration, the seal portion can be effectively functioned with a small exhaust amount, and dust generated inside the actuator can be more reliably prevented from flowing out. Further, the number of management items for managing the accuracy of the second gap of the throttle portion is small, and as a result, the yield in manufacturing the actuator can be improved.

  The annular member may include a connection portion connected to the housing base portion along an inner diameter of the groove portion, and a non-connection portion not including the connection portion.

  The annular member may have a connection portion connected to the housing base portion along an outer diameter of the groove portion and a non-connection portion not including the connection portion.

  Further, the annular member may be provided with a step corresponding to the second gap between the connection portion and the non-connection portion on a surface facing the housing base portion.

  Further, the housing base portion has a surface facing the annular member between the second radially inner surface of the groove portion and the radially outer surface of the groove portion. A step corresponding to the gap may be provided.

  The connecting member further includes a connecting member that connects the annular member and the housing base portion along an inner diameter of the groove, and the connecting member has a configuration in which the width in the linear motion direction corresponds to the second gap. There may be.

  The connecting member further includes a connecting member that connects the annular member and the housing base portion along the outer diameter of the groove, and the connecting member has a configuration in which the width in the linear motion direction corresponds to the second gap. It may be.

  As a desirable mode, it is preferable that the seal portion has a maximum width in the linear motion direction larger than a movement range of the rotor housing in the linear motion direction.

  With the above configuration, the seal portion is formed in the entire movement range of the rotor housing in the linear movement direction.

  Further, as a desirable aspect, a first bearing that rotatably supports the first rotor with respect to the stator housing, and a second bearing that rotatably supports the second rotor with respect to the first rotor. In addition, it is preferable that the first bearing and the second bearing are rolling bearings or sliding bearings.

  With the above configuration, an external drive source for driving the first bearing and the second bearing becomes unnecessary.

  Further, as a desirable aspect, a first bearing that rotatably supports the first rotor with respect to the stator housing, and a second bearing that rotatably supports the second rotor with respect to the stator housing are further provided. In addition, the first bearing and the second bearing are preferably rolling bearings or sliding bearings.

  With the above configuration, an external drive source for driving the first bearing and the second bearing becomes unnecessary.

  In addition, as a desirable mode, it further includes a flange portion fixed to the screw shaft, and a third bearing that rotatably supports the second rotor with respect to the flange portion, and the third bearing is a rolling bearing. Or it is preferable that it is a slide bearing.

  With the above configuration, an external drive source for driving the third bearing becomes unnecessary.

  In order to solve the above-described problems and achieve the object, the machine tool includes the actuator described above. Thereby, a machine tool suitable for use in a clean environment can be obtained.

  In order to solve the above-described problems and achieve the object, the measurement apparatus includes the actuator described above. Thereby, a measuring device suitable for use in a clean environment can be obtained.

  In order to solve the above-described problems and achieve the object, a semiconductor manufacturing apparatus includes the actuator described above. Thereby, a semiconductor manufacturing apparatus suitable for use in a clean environment can be obtained.

  In order to solve the above-described problems and achieve the object, the flat display manufacturing apparatus includes the actuator described above. Thereby, a flat display manufacturing apparatus suitable for use in a clean environment can be obtained.

  According to the present invention, it is possible to provide an actuator that can prevent foreign matter from entering the interior and more reliably prevent dust generated inside from flowing out to the outside.

FIG. 1 is a schematic diagram illustrating a schematic configuration of the actuator device according to the first embodiment. FIG. 2 is a cross-sectional view schematically illustrating the configuration of the actuator according to the first embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 3 is a schematic diagram schematically illustrating a plane of the rotor housing of the actuator according to the first embodiment when viewed from a direction parallel to the rotation center. FIG. 4 is a schematic diagram schematically showing a plane in which the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the first embodiment shown in FIG. 2 are viewed from a direction parallel to the rotation center. FIG. 5 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 4 as viewed from a direction parallel to the rotation center. FIG. 6 is an enlarged view in the alternate long and short dash line frame in the actuator according to the first embodiment shown in FIG. FIG. 7 is a cross-sectional view schematically showing an example of the stator by cutting the configuration of the actuator shown in FIG. 2 along a virtual plane orthogonal to the rotation center. FIG. 8 is a cross-sectional view schematically showing another example of the stator by cutting the configuration of the actuator shown in FIG. 2 along a virtual plane orthogonal to the rotation center. FIG. 9 is an explanatory diagram for explaining the operation of the actuator according to the first embodiment. FIG. 10 is a cross-sectional view schematically illustrating the configuration of an actuator according to a modification of the first embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 11 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the first embodiment shown in FIG. 10 when viewed from a direction parallel to the rotation center. FIG. 12 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 11 when viewed from a direction parallel to the rotation center. FIG. 13 is an enlarged view within a one-dot chain line frame in an actuator according to a modification of the first embodiment shown in FIG. FIG. 14 is a cross-sectional view schematically illustrating the configuration of the actuator according to the second embodiment by cutting along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 15 is a schematic diagram schematically showing a plane in which the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the second embodiment shown in FIG. 14 are viewed from a direction parallel to the rotation center. FIG. 16 is a schematic view schematically showing a plane when the annular member attached to the housing base portion shown in FIG. 15 is viewed from a direction parallel to the rotation center. FIG. 17 is an enlarged view within a one-dot chain line frame in the actuator according to the second embodiment shown in FIG. 14. FIG. 18 is a cross-sectional view schematically showing a configuration of an actuator according to a modification of the second embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 19 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the second embodiment shown in FIG. 18 as seen from the direction parallel to the rotation center. FIG. 20 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 19 as seen from the direction parallel to the rotation center. FIG. 21 is an enlarged view in a one-dot chain line frame in an actuator according to a modification of the second embodiment shown in FIG. FIG. 22 is a cross-sectional view schematically illustrating the configuration of the actuator according to the third embodiment by cutting along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 23 is a schematic diagram schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the second embodiment shown in FIG. 22 as seen from the direction parallel to the rotation center. FIG. 24 is a schematic diagram schematically showing a plane view of the annular member attached to the housing base portion shown in FIG. 23 via a connection member from a direction parallel to the rotation center. FIG. 25 is an enlarged view in the alternate long and short dash line frame in the actuator according to the third embodiment shown in FIG. FIG. 26 is a cross-sectional view schematically illustrating the configuration of an actuator according to a modification of the third embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 27 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the third embodiment shown in FIG. 26 when viewed from the direction parallel to the rotation center. FIG. 28 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 27 as seen from a direction parallel to the rotation center. FIG. 29 is an enlarged view in a one-dot chain line frame in an actuator according to a modification of the third embodiment shown in FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments (embodiments) for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited by the contents described in the following embodiments. The constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be appropriately combined.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a schematic configuration of the actuator device according to the first embodiment. As shown in FIG. 1, the actuator device 100 includes an actuator 1 and a control device (motor control circuit) 90. In the actuator 1, a part of the housing (housing) (stator housing 20) is supported by the support portion 95 with a fastening member. The fastening member is a screw, bolt, pin or the like. Thereby, the actuator 1 is fixed to the support part 95. In the actuator 1, the rotating body (revolved body) 10 rotates about the rotation center ZR and linearly moves in the linear motion direction (Z direction parallel to the rotation center ZR). For example, the actuator 1 can move the rotating body 10 from the dotted line position to the solid line position. Conversely, the actuator 1 can move the rotating body 10 from the solid line position to the dotted line position. The configuration of the actuator 1 will be described later. The control device 90 is a device that controls driving of the actuator 1.

  The control device 90 controls the rotation direction and rotation speed of the actuator 1 by controlling the current, voltage magnitude, frequency, and waveform supplied to the actuator 1, and the linear movement of the mover that moves in the linear movement direction is controlled. Control the moving direction and moving speed in the direction. For example, when a rotation command i is input from an external computer, the control device 90 outputs a drive signal from a CPU (Central Processing Unit) 91 to a three-phase amplifier (AMP) 92 and is driven from the AMP 92 to the actuator 1. A current Mi is supplied. The actuator 1 is configured such that the loading table 96 is rotated by the drive current Mi and the workpiece 97 is moved. When the loading table 96 rotates, a detection signal (resolver signal) Sr is output from an angle detector such as a resolver that detects a rotation angle described later. The control device 90 digitally converts the detection signal Sr by a resolver digital converter (RDC: Resolver to Digital Converter) 93. Based on the digital information of the detection signal Sr from the RDC 93, the CPU 91 determines whether or not the work 97 has reached the command position, and when it reaches the command position, stops the drive signal to the AMP 92.

  The work 97 is disposed on the rotating body 10 via the loading table 96. The workpiece 97 may be disposed directly on the rotating body 10 without using the loading table 96. The actuator device 100 controls the operation of the actuator 1 by the control device 90, and moves the work 97 or the loading platform 96 by moving the rotating body 10 of the actuator 1 in the linear motion direction (the arrow Z direction in FIG. 1). be able to.

  Next, the configuration of the actuator 1 will be described with reference to FIGS. FIG. 2 is a cross-sectional view schematically illustrating the configuration of the actuator according to the first embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 3 is a schematic diagram schematically illustrating a plane of the rotor housing of the actuator according to the first embodiment when viewed from a direction parallel to the rotation center.

  As shown in FIG. 2, the actuator 1 is a so-called brushless motor, and is disposed so as to be rotatable with respect to the ball screw shaft 15, a stator (hereinafter referred to as “stator”) 30 that is kept stationary, and the stator 30. The first rotor 50 and the second rotor 40 that are the two rotors, the stator housing 20 that is fixed to the above-described support portion 95 with the stator 30 fixed thereto, the ball screw shaft 15 and the screw fixed to the first rotor 50. And a mating nut 52.

  In the actuator 1 according to the first embodiment, the first rotor 50 rotates about the rotation center Zr, and the second rotor 40 rotates about the rotation center ZR at a position parallel to the rotation center Zr and different from the rotation center Zr. To do. As described above, in the actuator 1, the rotation centers of the first rotor 50 and the second rotor 40 that are two rotors arranged to be rotatable with respect to the stator 30 are not coaxial, and the rotation center ZR of the second rotor 40. Is eccentric with respect to the rotation center Zr.

  The ball screw shaft 15 is a rod-shaped member disposed at the rotation center Zr of the first rotor 50. Specifically, it is a screw shaft in which screw grooves are formed in a direction parallel to the rotation center Zr (linear movement direction). A flange portion 14 </ b> A is fixed to one end of the ball screw shaft 15. The flange portion 14A moves in a direction parallel to the rotation center Zr (linear movement direction) following the movement of the ball screw shaft 15. The nut 52 fixed to the first rotor 50 and screwed with the ball screw shaft 15 rotates about the rotation center Zr. In the actuator 1, since the ball rolls between the ball screw shaft 15 and the nut 52, the friction is small and the efficiency of making the rotational motion linear motion can be increased.

  In the actuator 1 according to the first embodiment described above, the ball screw shaft 15 may be another type of screw shaft. Examples of other types of screw shafts include a trapezoidal screw shaft and a triangular screw shaft. When other screw shafts such as a trapezoidal screw shaft and a triangular screw shaft are applied instead of the ball screw shaft 15, a screw shaft is obtained by using a frictional force in which a screw groove of the trapezoidal screw shaft or the triangular screw shaft is screwed with a nut The reverse operation of can be suppressed. The actuator 1 can minimize the rotational torque generated in the first rotor 50 in order to suppress reverse operation. For example, the actuator 1 can maintain the position of the screw shaft even when the excitation of the excitation coil 32 </ b> A that applies rotational torque to the first rotor 50 is stopped.

  The actuator 1 also has a rotating body (hereinafter referred to as “rotor housing”) 10 that rotates together with the second rotor 40, a flange portion 14A fixed to the ball screw shaft 15, and the second rotor 40 with respect to the flange portion 14A. And a third bearing 61 that is rotatably supported. With this structure, the actuator 1 can be moved in the linear motion direction while rotating the rotor housing 10.

  In the ball screw shaft 15, a linear motion transmission member 14 </ b> B constituting a flange portion 14 </ b> A of the ball screw shaft 15 is fixed by an annular fixing member 14 </ b> C in the vicinity of the end portion in the linear motion direction. For this reason, when the ball screw shaft 15 moves in the linear motion direction, the linear motion transmission member 14 </ b> B also moves together with the ball screw shaft 15. The linear motion transmission member 14B is a disk-shaped plate member, and the ball screw shaft 15 passes through the linear motion transmission member 14B. As shown in FIG. 3, the radially outer periphery of the linear motion transmission member 14B is circular. The center of the outer periphery in the radial direction of the linear motion transmission member 14B coincides with the rotation center ZR of the second rotor 40. The linear motion transmission member 14B includes a third bearing 61 that rotatably supports the rotor housing 10 on the outer periphery on the radially outer side.

  As shown in FIG. 2, the stator 30 includes a cylindrical stator core 31 and an excitation coil 32. In the stator 30, an exciting coil 32 is wound around a stator core 31. The exciting coil 32 is a linear electric wire. The exciting coil 32 is wound around the outer periphery of the stator core 31 via an insulating coil insulator. The stator 30 is connected to wiring for supplying power from the power source, and power is supplied from the control device 90 to the exciting coil 32 through this wiring. The exciting coil 32 includes an exciting coil 32A wound around a radially inner tooth of the stator core 31, which will be described later, and an exciting coil 32B wound around a radially outer tooth of the stator core 31.

  The first rotor 50 includes a rotor core 51, a first rotor bracket 53, and a fixing member 54. The fixing member 54 is a substantially disk-shaped member that has a hole into which the ball screw shaft 15 can be inserted and closes one open end of the first rotor bracket 53. The first rotor bracket 53, The nut 52 is connected. The fixing member 54 may be a member integrated with the nut 52. The first rotor bracket 53 fixes the rotor core 51 to the outer periphery.

  The second rotor 40 includes a rotor core 41 and an inner cylinder member 115 that is a cylindrical member that covers the radially outer side of the rotor core 41. The inner cylinder member 115 includes a second rotor bracket 42 and a support member 45. The support member 45 is integrated with the second rotor bracket 42, and the second rotor bracket 42 and the support member 45 rotate in conjunction with the rotation of the rotor core 41. Further, an outer ring of a second bearing 62 that supports the second rotor 40 rotatably with respect to the stator 30 is fixed to the radially inner wall surface of the support member 45. The support member 45 is a separate member from the second rotor bracket 42 and may be connected. The second rotor bracket 42 includes guide rails 114 that are fixed to the outer peripheral side of the second rotor bracket 42 and that extend in the linear motion direction and are arranged in the circumferential direction. For example, four guide rails 114 are equally arranged in the circumferential direction. The number of the guide rails 114 in the circumferential direction is not limited to the number described above, and an appropriate number is appropriately arranged.

  The stator core 31, the rotor core 41, and the rotor core 51 are manufactured by laminating thin plates such as electromagnetic steel plates and cold rolled steel plates by means of adhesion, boss, caulking, or the like. The stator core 31, the rotor core 41, and the rotor core 51 are sequentially stacked in the mold and discharged from the mold. The stator core 31, the rotor core 41, and the rotor core 51 may be powder magnetic cores obtained by solidifying magnetic powder.

  The rotor housing 10 has a plate portion 111 disposed on one end side in the linear movement direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as an axis, and an approximately larger inner diameter than the rotor core 41 and the second rotor bracket 42. A cylindrical outer cylinder portion 112 is provided. The outer cylinder portion 112 is integrated with the plate portion 111, extends in the linear movement direction from the radially outer end portion of the plate portion 111, is formed on the radially outer side of the second rotor 40, and interlocks with the rotation of the rotor core 41. Then, the plate part 111 and the outer cylinder part 112 rotate. The rotor housing 10 includes a lid member 11 that prevents foreign matter from entering the actuator 1 and preventing dust generated inside the actuator 1 from flowing out. Further, in the rotor housing 10, a slider 116 that slides on the guide rail 114 is fixed to the inner periphery on the radially inner side of the outer cylindrical portion 112. A plurality of sliders 116 are arranged in the circumferential direction by the same number as the number of guide rails 114 arranged in the circumferential direction. The rotor housing 10 may have a configuration in which a substantially cylindrical member constituting the outer cylinder portion 112 and a substantially disc-like member constituting the plate portion 111 are combined.

  The guide rail 114 described above includes a ball rolling raceway groove along a rail longitudinal direction on a pair of side surfaces. The U-shaped slider 116 attached so as to straddle the guide rail 114 includes a ball rolling track groove facing the ball rolling track groove of the guide rail 114. The slider 116 places a large number of balls in an infinite circulation path including a ball return penetrating hole penetrating the slider 116 in the longitudinal direction of the rail and a semicircular arc path provided in an end cap fixed to the end face of the slider 116. In addition, a large number of balls are circulated through a rolling path between the guide rail 114 and the ball rolling raceway groove of the slider 116. Thereby, the slider 116 can freely move in the rail longitudinal direction of the guide rail 114.

  The slider 116 and the guide rail 114 are linear motion guide mechanisms, and the guide rail 114 is supported by the slider 116 even if a force is applied to the slider 116 and a rotational moment is applied around the guide rail 114. For this reason, when the outer cylinder part 112 moves relatively with respect to the inner cylinder member 115, the rigidity of the rotary body 10 is high, and the movement operation can be stabilized. In the linear motion guide mechanism of the first embodiment, the outer cylinder portion 112 includes the slider 116 and the inner cylinder member 115 includes the guide rail 114. However, the outer cylinder portion 112 includes the guide rail 114 and the inner cylinder member. 115 may be provided with a slider 116.

  A plurality of sliders 116 may be attached to the same guide rail 114. When a plurality of sliders 116 are attached to the same guide rail 114, the sliders 116 are arranged at different positions in the linear motion direction, and the moment applied to the guide rail 114 is dispersed and received. For this reason, the rigidity of the rotating body 10 when the outer cylinder part 112 moves relative to the inner cylinder member 115 can be increased, and the movement operation can be stabilized.

  The stator housing 20 has a housing base portion 21 and a substantially cylindrical inner tube portion 211 having an outer diameter smaller than that of the outer tube portion 112. The inner cylinder part 211 is integrated with the housing base part 21, extends in the linear movement direction from the radially outer end of the housing base part 21, and is formed on the radially inner side of the outer cylinder part 112. As a material for forming the housing base portion 21 and the outer cylinder portion 112, for example, a general steel material such as SPCC (Steel Plate Cold Commercial), electromagnetic soft iron, or the like can be applied. The stator housing 20 includes a housing inner 22 and an annular member 23. A support member 35 that fixes the stator 30 is connected to the housing inner 22. The housing base portion 21 fixes the stator 30 via the housing inner 22 and the support member 35.

  A first bearing 63 that rotatably supports the first rotor 50 and the first rotor bracket 53 with respect to the stator housing 20 is fixed to the radially inner wall surface of the housing inner 22. Alternatively, the first bearing 63 may be fixed to the radially inner wall surface of the support member 35. In addition, the 1st bearing 63 is comprised by 1st bearing 63A, 63B of a back surface combination.

  A second bearing 62 that rotatably supports the inner cylinder member 115 and the second rotor 40 with respect to the stator housing 20 is fixed to a wall surface on the radially outer side of the housing inner 22. Alternatively, the second bearing 62 may be fixed to the radially outer wall surface of the support member 35. As described above, the actuator 1 includes the first bearing 63 that rotatably supports the first rotor 50 with respect to the stator housing 20, and the second bearing 62 that rotatably supports the second rotor 40 with respect to the stator housing 20. And including. The second bearing 62 does not support the first rotor bracket 53. For this reason, when the second rotor 40 starts to rotate, the reaction force received from the second rotor 40 acts on the first rotor bracket 53 as the starting friction torque of the second bearing 62, causing unintended rotation of the first rotor 50. The possibility of causing it can be suppressed.

  In the example shown in FIG. 2, the first bearing 63B and the second bearing 62 are on the same plane obtained by cutting the configuration of the actuator 1 by a virtual plane orthogonal to the rotation center Zr (rotation center ZR). For this reason, the difference between the position supporting the first rotor 50 and the first rotor bracket 53 and the position supporting the inner cylinder member 115 and the second rotor 40 is reduced, and the height of the actuator 1 in the linear motion direction is reduced. be able to. The arrangement of the bearings such as the first bearing 63B and the second bearing 62 is not limited to this, and for example, the first rotor 50 and the second rotor 40 in the radial direction due to errors in the magnet mounting positions of the first rotor 50 and the second rotor 40, for example. It is preferable that the arrangement be such that moment force does not act on the bearing when the force that pulls the second rotor 40 is applied. For example, by disposing the bearings at both ends of the stator core 31 in the linear motion direction, the moment force acting on the bearing can be suppressed, and the rotation of the first rotor 50 and the second rotor 40 can be stabilized. Further, the center position in the linear motion direction between the bearings arranged at both ends of the stator core 31 in the linear motion direction and the central position in the linear motion direction of the magnets of the first rotor 50 and the second rotor 40 are the rotation center Zr (rotation center). ZR), the moment force acting on the bearing can be further suppressed and the rotation of the first rotor 50 and the second rotor 40 can be further stabilized. it can.

  Next, the rotor housing 10 and the stator housing 20 of the actuator 1 according to this embodiment will be described in detail with reference to FIGS. 1, 4, 5, and 6. FIG. 4 is a schematic diagram schematically showing a plane in which the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the first embodiment shown in FIG. 2 are viewed from a direction parallel to the rotation center. FIG. 5 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 4 as viewed from a direction parallel to the rotation center. FIG. 6 is an enlarged view in the alternate long and short dash line frame in the actuator according to the first embodiment shown in FIG.

  As shown in FIGS. 2 and 4, the stator housing 20 is a substantially disk-shaped housing base portion 21 that is disposed on the other end side in the linear motion direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as an axis. A substantially cylindrical inner cylindrical portion 211 whose outer diameter is smaller than the inner diameter of the outer cylindrical portion 112 of the rotor housing 10, a substantially annular convex portion 212 to which the housing inner 22 is connected, and an outer diameter of the convex portion 212. A substantially annular groove portion 213 formed on a surface of the housing base portion 21 on the inner cylinder portion 211 side with the rotation center of the second rotor 40 as an axis, and a wall surface on the outer diameter side of the groove portion 213. Exhaust air that extends in one direction in the radial direction, penetrates through the housing base portion 21 and is sucked and exhausted by the suction exhaust device 98 inside the air surrounded by the rotor housing 10 and the stator housing 20. And a hole 214. The surface 216 radially inward from the inner diameter of the groove 213 of the housing base 21 and the surface 215 radially outer than the outer diameter of the groove 213 are on the same plane at the same position in the linear motion direction.

  The inner cylinder portion 211 extends in the linear motion direction from the radially outer end of the housing base portion 21 and is formed on the radially inner side of the outer cylinder portion 112 of the rotor housing 10. A seal portion 217 is formed that overlaps with the inner cylinder portion 211 of the housing base portion 21 in a radial direction with a gap (hereinafter referred to as “first gap”) 218 of about 0.1 mm to 0.5 mm, for example.

  As shown in FIGS. 2 and 5, the annular member 23 is a substantially annular member whose inner diameter is smaller than the inner diameter of the groove portion 213 formed in the housing base portion 21 and whose outer diameter is larger than the outer diameter of the groove portion 213. It is.

  The annular member 23 has a substantially annular connecting portion 231 that contacts the housing base portion 21 along the inner diameter of the groove portion 213, and a non-connecting portion 232 that does not include the connecting portion 231. As shown in FIGS. 2 and 6, when the annular member 23 is combined with the housing base portion 21 and the annular member 23, the housing base portion 21 along the outer diameter of the annular member 23 and the groove portion 213 is used. A diaphragm portion 233 that overlaps with the surface 215 radially outside the outer diameter of the groove portion 213 in the linear motion direction with a gap (hereinafter referred to as “second gap”) 234 of, for example, about several μm to several tens μm. Is formed between the connection portion 231 and the non-connection portion 232 so as to correspond to the second gap 234.

  The housing base portion 21 and the annular member 23 may be connected using, for example, a plurality of fastening members such as screws, or the housing base portion 21 and the connecting portion 231 of the annular member 23 may be bonded or bonded. You may weld and connect.

  FIG. 7 is a cross-sectional view schematically showing an example of the stator by cutting the configuration of the actuator shown in FIG. 2 along a virtual plane orthogonal to the rotation center. The first rotor 50 is provided in a cylindrical shape so as to surround the ball screw shaft 15 on the rotation center Zr side. The stator 30 is provided in a cylindrical shape so as to surround the first rotor 50 on the rotation center Zr side. The second rotor 40 is provided in a cylindrical shape so as to surround the stator 30 on the rotation center Zr side.

  As described above, in the actuator 1, the first rotor 50 rotates around the rotation center Zr, and the second rotor 40 rotates around the rotation center ZR that is parallel to the rotation center Zr and different from the rotation center Zr. Therefore, in the stator core 31 of the stator 30, the center of the outer peripheral arc OT connecting the radially outermost positions of the outer teeth 36 in the circumferential direction is made to coincide with the rotation center ZR. Further, the stator core 31 has the center of the inner circumferential arc IT connecting the radially innermost position of the inner teeth 38 in the circumferential direction aligned with the rotation center Zr. The stator core 31 shown in FIG. 7 has a constant radial width BH of the annular back yoke 37, protrudes radially inward from the back yoke 37, and the protruding lengths of a plurality of inner teeth 38 provided in the circumferential direction. Are the same IH. The radial width SH of the slit portion 39A is the same in the slit portion 39A provided in the circumferential direction. The stator core 31 protrudes radially outward from the back yoke 37, and the protruding lengths of the plurality of outer teeth 36 provided in the circumferential direction are changed so that the center of the outer peripheral arc OT coincides with the rotation center ZR. , Different.

  As shown in FIG. 7, when the configuration of the actuator 1 is viewed on a virtual plane orthogonal to the rotation center Zr, the protruding length OH1 of the outer teeth 36 on the virtual straight line connecting the rotation center Zr and the rotation center ZR, and the outer teeth 36 The length differs from the protrusion length OH2. The protrusion length OH1 of the outer teeth 36 is the minimum length in the circumferential direction among the protrusion lengths of the outer teeth 36. Further, the protruding length OH2 of the outer teeth 36 is the maximum length in the circumferential direction among the protruding lengths of the outer teeth 36. With this structure, the stator core 31 decenters the center of the outer peripheral arc OT and the center of the inner peripheral arc IT. Then, the rotation center of the first rotor 50 and the rotation center of the second rotor 40 are in parallel and different positions, and the actuator 1 can suppress the rotation of the screw shaft accompanying the rotation of the second rotor 40.

  As a modification, the stator core 31 may have the same protruding length of the plurality of outer teeth 36 provided in the circumferential direction, and the center of the outer circumferential arc OT may be aligned with the rotation center Zr. In the case of this modification, the protruding lengths of the plurality of inner teeth 38 projecting radially outward from the back yoke 37 and the circumferential direction are set so that the center of the inner circumferential arc IT coincides with the rotation center ZR. Alternatively, the center of the outer circumference arc OT and the center of the inner circumference arc IT may be decentered. With this structure, in the actuator 1, the first rotor 50 rotates about the rotation center ZR, and the second rotor 40 rotates about the rotation center Zr.

  FIG. 8 is a cross-sectional view schematically showing another example of the stator by cutting the configuration of the actuator shown in FIG. 2 along a virtual plane orthogonal to the rotation center. The stator core 31 shown in FIG. 8 has the center of the outer circumferential arc 37OB on the radially outer side of the annular back yoke 37 aligned with the rotation center ZR, and the center of the inner arc 37IB on the radially inner side of the back yoke 37. The width in the radial direction of the back yoke 37 is changed to the circumferential direction so as to coincide with Zr. Viewing the configuration of the actuator 1 in a virtual plane orthogonal to the rotation center Zr, the radial width BH1 of the back yoke 37 on the virtual line connecting the rotation center Zr and the rotation center ZR, and the radial width BH2 of the back yoke 37 Is different in length. The radial width BH1 of the back yoke 37 is the smallest width in the circumferential direction of the radial width of the back yoke 37. Further, the radial width BH <b> 2 of the back yoke 37 is the maximum width in the circumferential direction among the radial widths of the back yoke 37.

  The radial width of the slit portion 39 </ b> A increases in accordance with the radial width of the back yoke 37. For example, the radial width SH1 of the slit portion 39A included in the radial width BH1 of the back yoke 37 is the smallest width in the circumferential direction among the radial widths of the slit portion 39A. Similarly, the radial width SH2 of the slit portion 39A included in the radial width BH2 of the back yoke 37 is the maximum width in the circumferential direction among the radial widths of the slit portion 39A. Since the radial width of the slit portion 39A changes according to the radial width of the back yoke 37, the distribution of the magnetic flux in the circumferential direction of the back yoke 37 can be made uniform. With this structure, the outer teeth 36 and the inner teeth 38 aligned on the radial extension line are magnetically separated by the gap of the slit portion 39A. The inner back yoke inside the radial direction of the slit portion 39A and the outer back yoke outside the radial direction of the slit portion 39A have the same radial width in the circumferential direction. It is magnetically separated by a gap of 39A. For this reason, possibility that the outer teeth 36 and the inner teeth 38 will affect each other is reduced, and the rotational accuracy of the first rotor 50 and the rotational accuracy of the second rotor 40 can be increased.

  The stator core 31 protrudes radially inward from the back yoke 37, and the protruding lengths of the plurality of inner teeth 38 provided in the circumferential direction have the same IH. The stator core 31 protrudes radially outward from the back yoke 37, and the protruding lengths of the plurality of outer teeth 36 provided in the circumferential direction have the same OH. Therefore, the outer circumference arc OT has a radius larger than that of the outer circumference side arc 37OB, and the centers of the outer circumference side arc 37OB and the outer circumference arc OT coincide with the rotation center ZR. Further, the inner circumferential arc IT has a radius smaller than the inner circumferential arc 37IB, and the centers of the inner circumferential arc 37IB and the inner circumferential arc IT coincide with the rotation center Zr. With this structure, the stator core 31 decenters the center of the outer peripheral arc OT and the center of the inner peripheral arc IT. Then, the rotation center of the first rotor 50 and the rotation center of the second rotor 40 are in parallel and different positions, and the actuator 1 can suppress the rotation of the screw shaft accompanying the rotation of the second rotor 40.

  The control device 90 of the actuator device 100 outputs a drive signal from a CPU (Central Processing Unit) 91 to a three-phase amplifier (AMP) 92, and the drive current Mi is supplied from the AMP 92 to the actuator 1. The actuator 1 independently drives the excitation coils 32A and 32B shown in FIG. 2 described above according to the drive current Mi. As a result, the control device 90 can control the driving or stopping of the first rotor 50 independently of the driving or stopping of the second rotor 40. Similarly, the control device 90 can control the driving or stopping of the second rotor 40 independently of the driving or stopping of the first rotor 50. And the control apparatus 90 can control the rotation speed and rotation direction of the 2nd rotor 40, and the rotation speed and rotation direction of the 1st rotor 50 mutually independently.

  The actuator 1 preferably includes angle detectors 71 and 74. The angle detectors 71 and 74 are, for example, resolvers. The angle detector 71 can detect the rotational position of the second rotor 40 with high accuracy. The angle detector 74 can detect the rotational position of the first rotor 50 with high accuracy. Hereinafter, although the case where the angle detectors 71 and 74 are resolvers will be described, the angle detector may be another sensor or encoder, and is not limited to the type of detector.

  Angle detectors 71 and 74 are resolver stators 72 and 75 that are kept stationary, and resolver rotors that are disposed to face resolver stators 72 and 75 with a predetermined gap therebetween and are rotatable with respect to resolver stators 72 and 75. 73 and 76 are provided. The resolver stators 72 and 75 are disposed on the housing base portion 21. The resolver rotor 73 is disposed on the support member 45 of the second rotor 40. The resolver rotor 76 is disposed on the first rotor bracket 53 of the first rotor 50.

  When the exciting coil 32 of the stator 30 is excited and the first rotor 50 and the second rotor 40 are rotationally driven, the resolver rotors 73 and 76 are rotationally driven simultaneously.

  The resolver stators 72 and 75 have an annular laminated core in which a plurality of stator magnetic poles are formed at equal intervals in the circumferential direction, and a resolver coil is wound around each stator magnetic pole. Each resolver coil is connected to a wiring for outputting a detection signal (resolver signal) Sr.

  The resolver rotors 73 and 76 are constituted by hollow annular laminated iron cores. The arrangement positions of the angle detectors 71 and 74 are not particularly limited as long as the rotations of the first rotor 50 and the second rotor 40 can be detected, and are arranged at arbitrary positions according to the shape of the stator housing 20. Can be set.

  In the angle detectors 71 and 74, the reluctance between the resolver rotors 73 and 76 and the resolver stators 72 and 75 changes continuously. The angle detectors 71 and 74 detect a change in reluctance, and the RDC 93 converts the detection signal Sr described above into a digital signal. The CPU 91 of the control device 90 that controls the actuator 1 can calculate the position and rotation angle of the rotating body 10 and the ball screw shaft 15 linked to the resolver rotors 73 and 76 per unit time based on the electrical signal of the RDC 93. it can. As a result, the control device 90 that controls the actuator 1 can measure the rotation state of the rotating body 10 (for example, the rotation speed, the rotation direction, or the rotation angle) and the movement position of the ball screw shaft 15 in the linear movement direction. Become.

  The angle detectors 71 and 74 described above output a unipolar resolver signal that outputs a single-pole resolver signal in which the fundamental wave component of the reluctance change is one cycle for each rotation of the first rotor 50 or the second rotor 40, It is preferable to combine with a so-called multipolar resolver that outputs a multipolar resolver signal in which the fundamental wave component of the reluctance change has multiple cycles per rotation of one rotor 50 or the second rotor 40.

  As described above, the actuator 1 includes the angle detectors having different periods of the fundamental wave component of the reluctance change for each rotation of the first rotor 50 or the second rotor 40, so that the first rotor 50 or the second rotor 40 The absolute position can be grasped, and the accuracy of measuring the rotation state (for example, the rotation speed, the rotation direction, or the rotation angle) of the first rotor 50 or the second rotor 40 can be improved. In addition, the actuator 1 can perform positioning without having to perform a pole detection operation by one-phase energization or an origin return operation.

  The exciting coil 32A described above may include a plurality of winding circuits, and the timing for driving each winding circuit may be changed by pulse driving. The exciting coil 32B described above may include a plurality of winding circuits, and the timing for driving each winding circuit may be changed by pulse driving. As a result, the rotor core 41 and the rotor core 51 are in a state where so-called stepping motors, in which the excitation coils 32A and 32B are pulse-driven and rotate independently in synchronization with the pulse drive, are arranged inside and outside. The control device 90 described above can control the drive or stop of the first rotor 50 independently of the drive or stop of the second rotor 40 by controlling the pulse of the drive current Mi. As a result, the actuator 1 can position the first rotor 50 and the second rotor 40 without providing the angle detectors 71 and 74. The actuator 1 can save space and reduce costs by reducing the number of parts. Moreover, the actuator 1 can improve reliability by reducing the number of parts.

  Next, the actuator device 100 and the actuator 1 will be described with reference to FIGS. 1, 2, 3, and 9. FIG. 9 is an explanatory diagram for explaining the operation of the actuator according to the first embodiment. The control device 90 of the actuator device 100 shown in FIG. 1 applies, for example, alternating current to the excitation coil 32 of the stator 30 and switches the voltage applied to the excitation coil 32 at a predetermined cycle, so that the first rotor is switched with respect to the stator 30. 50 and the second rotor 40 generate a driving force for rotation.

  When the first rotor 50 of the actuator 1 rotates, the nut 52 fixed to the first rotor bracket 53 also rotates. When the nut 52 rotates, the thread groove of the ball screw shaft 15 moves in the linear motion direction along the thread groove of the nut 52. Thereby, the ball screw shaft 15 moves in the linear motion direction relative to the nut 52 as the nut 52 rotates. As shown in FIGS. 2 and 9, the actuator 1 can move the ball screw shaft 15 from the bottom to the top on the front surface of the paper according to the rotation of the nut 52. Contrary to the operation shown in FIG. 9, the ball screw shaft 15 can be moved from the top to the bottom on the front surface of the paper according to the reverse rotation of the nut 52. As shown in FIGS. 2 and 9, the linear motion transmission member 14 </ b> B moves from the bottom to the top or from the top to the bottom on the front surface of the paper according to the movement of the ball screw shaft 15. The rotor housing 10 is rotatably supported by the linear motion transmission member 14 </ b> B by the third bearing 61. For this reason, according to the movement of the linear motion transmission member 14B, the rotor housing 10 moves up and down in the linear motion direction.

  The second rotor 40 also rotates independently of the rotation operation in which the first rotor 50 of the actuator 1 rotates. When the second rotor 40 rotates, the inner cylinder member 115, the second rotor bracket 42, and the support member 45 rotate in conjunction with the rotation of the rotor core 41. Further, the guide rail 114 slid on the slider 116 rotates together with the inner cylinder member 115 (the second rotor bracket 42 of the second rotor 40), whereby the rotor housing 10 rotates.

  As described above, the rotor housing 10 is rotatably supported by the linear motion transmission member 14 </ b> B by the third bearing 61. When the second rotor 40 rotates, in conjunction with the rotation of the rotor core 41, the rotor housing 10 shown in FIG. 2 rotates around the linear motion transmission member 14B around the rotation center ZR. The force with which the rotation of the rotor housing 10 rotates the linear motion transmission member 14B via the third bearing 61 attempts to rotate the linear motion transmission member 14B around the rotation center ZR. For this reason, a rotational force is applied to the ball screw shaft 15 fixed to the linear motion transmission member 14B to rotate about the rotation center ZR. Here, the rotation center of the nut 52 screwed with the ball screw shaft 15 coincides with the rotation center Zr. As the deviation between the rotation center Zr and the rotation center ZR is larger, the rotational force for rotating the ball screw shaft 15 around the rotation center ZR is not converted to the rotational force for rotating the ball screw shaft 15 and rotating the nut 52. A large resistance force is generated between the ball screw shaft 15 and the nut 52 to be screwed. As a result, the actuator 1 can suppress the rotation of the ball screw shaft 15 accompanying the rotation of the rotor housing 10.

  The actuator 1 according to the first embodiment described above is assumed to be used in, for example, a machine tool, a measuring device, a semiconductor manufacturing device, or a flat panel display manufacturing device. High reliability is required for the actuator 1 used in such applications. Further, in the manufacture of semiconductor elements, flat panel displays, etc., a manufacturing process in a clean environment is required in order to avoid dust contamination in the product. In order to ensure high reliability, an actuator used in such a clean environment must prevent foreign matter from entering the actuator and prevent dust generated inside the actuator from flowing out. is there.

  As the dust generation generated inside the actuator, the generation of lubricating grease generated from various bearings, linear motion guide mechanisms, ball screws, and the like can be considered. Dust particles generated from the lubricating grease become a source of contamination in the manufacturing process of semiconductor elements and flat panel displays in a clean environment, and cause defects that lose product value. For this reason, in actuators used in the manufacturing process of semiconductor elements, flat panel displays, etc., low dust generation grease with low dust generation properties is used as lubricating grease used for various bearings, linear motion guide mechanisms, ball screws, and the like. Is common.

  As described above, in the actuator 1 according to the first embodiment, the outer cylinder portion 112 of the rotor housing 10 and the inner cylinder portion 211 of the housing base portion 21 have a first diameter of about 0.1 mm to 0.5 mm, for example, in the radial direction. A seal portion 217 that overlaps with the gap 218 is formed. By forming the seal portion 217 in the entire movement range of the rotor housing 10 in the linear movement direction, foreign matter can be prevented from entering the actuator 1.

  As shown in FIGS. 2 and 9, the width of the seal portion 217 in the linear motion direction changes when the rotor housing 10 is moved up and down in the linear motion direction. In other words, when the rotor housing 10 is at the lowest position in the linear motion direction, the width of the seal portion 217 is maximized, and when the rotor housing 10 is at the uppermost portion in the linear motion direction, the linear motion of the seal portion 217 is achieved. The direction width is minimized.

  The moving range of the rotor housing 10 in the linear motion direction is regulated by the moving range of the slider 116 with respect to the guide rail 114. The moving range of the slider 116 with respect to the guide rail 114 is determined by the relative positional relationship of the linear motion transmission member 14B with respect to the nut 52 in the linear motion direction. That is, the range of movement of the rotor housing 10 in the linear motion direction is a range restricted by the minimum position and the maximum position in the linear motion direction that can be taken by the position of the linear motion transmission member 14B relative to the nut 52. Become.

  Here, when the maximum width of the seal portion 217 in the linear motion direction is smaller than the movement range of the rotor housing 10 in the linear motion direction, the outer cylinder portion of the rotor housing 10 is located at the uppermost position of the rotor housing 10 in the linear motion direction. 112 and the inner cylinder part 211 of the housing base part 21 do not overlap in the radial direction. Therefore, the actuator 1 according to this embodiment needs to be configured such that the maximum width of the seal portion 217 in the linear motion direction is larger than the movement range of the rotor housing 10 in the linear motion direction.

  As described above, in the actuator 1 according to the first embodiment, the housing base portion 21 includes the substantially annular groove portion 213 having the rotation center of the second rotor 40 as an axis, and the radial direction from the outer wall of the groove portion 213. And an exhaust hole 214 that is perforated through the housing base portion 21 is formed, the inner diameter is smaller than the inner diameter of the groove portion 213 formed in the housing base portion 21, and the outer diameter is the outer diameter of the groove portion 213. When the housing base portion 21 and the annular member 23 are combined, the annular member 23 and the groove portion 213 of the housing base portion 21 along the outer diameter of the groove portion 213 are provided. A diaphragm portion 233 is formed such that a surface 215 radially outside the outer diameter of the rotor housing 10 overlaps with the second gap 234 of about several μm to several tens of μm, for example, in the linear motion direction of the rotor housing 10. Has been.

  In the present embodiment, in the configuration described above, it is assumed that a suction exhaust device 98 such as a vacuum pump is connected to the exhaust hole 214 provided in the housing base portion 21. When the suction / exhaust device 98 is operated, the air inside the actuator 1 is sucked out through the exhaust hole 214, the groove 213, and the throttle 233.

  In the actuator 1 according to the first embodiment, the throttle portion 233 is formed over the entire circumference, and the second gap 234 of the throttle portion 233 is extremely small, about several μm to several tens μm. Even if the air suction force of the device 98 is small and the displacement is small, the pressure of the air in the groove 213 is smoothed. For this reason, the air inside the actuator 1 is uniformly sucked over the entire circumference of the throttle portion 233. Thereby, the pressure difference in the circumferential direction inside the actuator 1 is suppressed.

  As described above, in the actuator 1 according to the first embodiment, the first gap 218 of the seal portion 217 is, for example, about 0.1 mm to 0.5 mm, which is larger than the second gap 234 of the throttle portion 233. Since the pressure difference in the circumferential direction inside the actuator 1 is suppressed by the throttle portion 233 described above, even if the first gap 218 of the seal portion 217 is relatively large, for example, about 0.1 mm to 0.5 mm, the seal portion Air is uniformly sucked into the actuator 1 over the entire circumference of 217. In other words, in the actuator 1 according to the first embodiment, air uniformly flows into the inside of the actuator 1 over the entire circumference in the circumferential direction of the seal portion 217, so that the throttle portion 233 causes the circumferential in the actuator 1 to move in the circumferential direction. Since the pressure difference is suppressed, it is possible to reliably prevent the dust generated inside the actuator 1 from flowing out. Thus, the actuator 1 according to Embodiment 1 can effectively cause the seal portion 217 to function with a small displacement.

  Further, since it is possible to prevent dust generated inside the actuator 1 from flowing out from the seal portion 217, in the actuator 1 according to the first embodiment, the first bearing 63 (63A, 63B), the second As the bearing 62 and the third bearing 61, for example, a mechanical bearing that does not require an external power source such as a power source or compressed air, such as a rolling bearing or a sliding bearing, can be used.

  Further, the linear motion guide mechanism including the first bearing 63 (63A, 63B), the second bearing 62, the third bearing 61, the slider 116 and the guide rail 114, and the thread groove of the ball screw shaft 15 and the thread groove of the nut 52 It is not necessary to use a low dust generation grease having a low dust generation property as a lubrication grease for lubricating a movable portion such as a fitting portion, and an optimum lubrication grease can be used according to driving conditions.

  In the configuration of the actuator 1 according to the present embodiment, the groove portion 213 formed in the housing base portion 21, the exhaust hole 214, the outer cylinder portion 112 of the rotor housing 10, and the inner cylinder portion 211 of the stator housing 20 are formed. The configuration excluding the seal portion 217, the annular member 23, and the throttle portion 233 formed by the housing base portion 21 and the annular member 23 is not limited to the configuration described above, and other configurations are applicable. .

  Further, in the configuration of the actuator 1 according to the present embodiment, in order to manage the accuracy of the second gap 234 of the throttle portion 233, the flatness of the surface 215 and the surface 216 of the housing base portion 21, the flatness of the housing base portion 21, It is only necessary to provide the flatness and step of the surface of the connecting portion 231 and the surface of the non-connecting portion 232 of the annular member 23 facing the surface 215 and the surface 216 as management items, and the management items for component accuracy can be reduced. There are advantages. As a result, the yield is improved.

(Modification)
FIG. 10 is a cross-sectional view schematically illustrating the configuration of an actuator according to a modification of the first embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 11 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the first embodiment shown in FIG. 10 when viewed from a direction parallel to the rotation center. FIG. 12 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 11 when viewed from a direction parallel to the rotation center. FIG. 13 is an enlarged view within a one-dot chain line frame in an actuator according to a modification of the first embodiment shown in FIG. In addition, the same code | symbol is attached | subjected to the same component as the actuator 1 which concerns on Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  In the stator housing 20 of the actuator 1 according to the first embodiment described above, the surface of the annular member 23 facing the housing base portion 21 corresponds to the second gap 234 between the connection portion 231 and the non-connection portion 232. In the stator housing 20a of the actuator 1a according to the modification of the first embodiment, as shown in FIGS. 10 to 13, a step is provided between the connection portion 231a and the non-connection portion 232a. Without providing, a step corresponding to the second gap 234 is provided between the surface 216a radially inward from the inner diameter of the groove 213 of the housing base 21a and the surface 215a radially outer than the outer diameter of the groove 213, An aperture 233a is formed.

  In this modified example, in order to manage the accuracy of the second gap 234 of the throttle portion 233a, the flatness and level difference of the surface 215a and the surface 216a of the housing base portion 21a, the surface 215a and the surface 216a of the housing base portion 21a, The flatness of the connecting portion 231a surface and the non-connecting portion 232a surface of the facing annular member 23a only needs to be provided as management items, and the advantage that the number of component accuracy management items can be reduced as in the above-described example. There is. As a result, the yield is improved.

  The housing base portion 21a and the annular member 23a may be connected using, for example, a plurality of fastening members such as screws, as in the above-described example, or the housing base portion 21a and the annular member 23a may be connected to each other. The connection portion 231a may be bonded or welded.

  As described above, the actuator 1 according to the first embodiment includes the stator 30, the stator housing 20, the first rotor 50, the ball screw shaft 15, the nut 52, the second rotor 40, and the rotor housing 10. Including. The rotor housing 10 includes a substantially disc-shaped plate portion 111 disposed on one end side in the linear movement direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as an axis, and a radially outer end portion of the plate portion 111. And an outer cylindrical portion 112 formed on the radially outer side of the second rotor 40 and extending in the linear motion direction. The stator housing 20 includes a substantially disk-shaped housing base portion 21 disposed on the other end side in the linear movement direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as an axis, and a radially outer side of the housing base portion 21. An inner cylinder portion 211 that forms a seal portion 217 that extends in the linear motion direction from the end portion and is formed on the radially inner side of the outer cylinder portion 112 and that overlaps the outer cylinder portion 112 in the radial direction across the first gap 218; There is an exhaust hole 214 for sucking and exhausting the air enclosed by the rotor housing 10 and the stator housing 20 by the suction exhaust device 98.

  In this structure, by connecting the suction / exhaust device 98 to the exhaust hole 214 provided in the housing base portion 21 and operating the suction / exhaust device 98, the air inside the actuator 1 is uniformly sucked from the exhaust hole 214. The air is uniformly sucked into the actuator 1 from the seal portion 217. Thereby, it is possible to prevent foreign matter from entering the inside of the actuator 1 and reliably prevent dust generated inside the actuator 1 from flowing out to the outside.

  In addition, a substantially annular groove portion 213 formed on the surface of the housing base portion 21 on the inner cylinder portion 211 side with the rotation center of the second rotor 40 as an axis, an inner diameter is smaller than an inner diameter of the groove portion 213, and an outer diameter is It is a substantially annular member that is larger than the outer diameter of the groove portion 213 and covers the groove portion 213 in the linear motion direction, and in the linear motion direction with the surface on the inner tube portion 211 side of the housing base portion 21 across the second gap 234. The exhaust hole 214 is formed to extend from the outer diameter side wall surface of the groove portion 213 in one radial direction and penetrate the housing base portion 21. As a result, the seal portion 217 can be effectively functioned with a small displacement, and the dust generated inside the actuator 1 can be more reliably prevented from flowing out. Further, the number of management items for managing the accuracy of the second gap 234 of the aperture 233 is reduced, and as a result, the yield in manufacturing the actuator 1 can be improved.

  The actuator 1 may be a mechanical bearing that does not require an external power source such as a power source or compressed air, such as a rolling bearing or a sliding bearing.

  In addition, the actuator 1 does not need to use a low dust generation grease having a low dust generation property as a lubrication grease for lubricating the movable part, and can use an optimum lubrication grease according to driving conditions.

(Embodiment 2)
FIG. 14 is a cross-sectional view schematically illustrating the configuration of the actuator according to the second embodiment by cutting along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 15 is a schematic diagram schematically showing a plane in which the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the second embodiment shown in FIG. 14 are viewed from a direction parallel to the rotation center. FIG. 16 is a schematic view schematically showing a plane when the annular member attached to the housing base portion shown in FIG. 15 is viewed from a direction parallel to the rotation center. FIG. 17 is an enlarged view within a one-dot chain line frame in the actuator according to the second embodiment shown in FIG. 14. In addition, the same code | symbol is attached | subjected to the same component as embodiment mentioned above, and the overlapping description is abbreviate | omitted.

  As shown in FIGS. 14 and 15, the stator housing 20 b is a substantially circular shape that is disposed on the other end side in the linear movement direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as the axis, as in the first embodiment. A plate-shaped housing base portion 21b, a substantially cylindrical inner cylinder portion 211 whose outer diameter is smaller than the inner diameter of the outer cylinder portion 112 of the rotor housing 10, and a substantially annular convex portion 212 to which the housing inner 22 is connected; A substantially annular groove 213 formed on a surface of the housing base portion 21b on the side of the inner cylinder portion 211 with the rotation center of the second rotor 40 as an axis, and a groove portion 213. The inner wall surrounded by the rotor housing 10 and the stator housing 20b is sucked and exhausted by extending in one direction in the radial direction from the wall surface on the outer diameter side and penetrating through the housing base portion 21b. And an exhaust hole 214 for sucking exhaust by location 98. The surface 216b radially inward from the inner diameter of the groove portion 213 of the housing base 21b and the surface 215b radially outer than the outer diameter of the groove portion 213 are on the same plane where the positions in the linear motion direction are equal.

  The inner cylinder portion 211 extends in the linear motion direction from the radially outer end of the housing base portion 21 b and is formed on the radially inner side of the outer cylinder portion 112 of the rotor housing 10. A seal portion 217 that overlaps the inner cylinder portion 211 of the housing base portion 21b in the radial direction with a first gap 218 of about 0.1 mm to 0.5 mm, for example, is formed.

  As shown in FIGS. 14 and 16, the annular member 23b has an inner diameter smaller than the inner diameter of the groove portion 213 formed in the housing base portion 21b and an outer diameter smaller than the outer diameter of the groove portion 213, as in the first embodiment. It is a large substantially annular member.

  The annular member 23b has a substantially annular connecting portion 231b that contacts the housing base portion 21b along the outer diameter of the groove portion 213, and a non-connecting portion 232b that does not include the connecting portion 231b. As shown in FIGS. 14 and 17, when the annular member 23 b is combined with the annular base member 23 b, the annular annular member 23 b and the annular groove member 213 are formed on the housing base portion 21 b along the inner diameter of the groove portion 213. A connecting portion 231b is formed so that a constricted portion 233b is formed such that the surface 216b radially inward from the inner diameter of the groove portion 213 is overlapped in the linear motion direction with a second gap 234 of, for example, about several μm to several tens μm. And a non-connection portion 232b, a step corresponding to the second gap 234 is provided.

  The housing base portion 21b and the annular member 23b may be connected using a fastening member such as a plurality of screws, for example, as in the first embodiment, or the housing base portion 21b and the annular member 23b may be connected to each other. The connection portion 231b may be connected by bonding or welding.

  In the second embodiment, in order to manage the accuracy of the second gap 234 of the throttle portion 233b, the flatness of the surfaces 215b and 216b of the housing base portion 21b, and the surfaces 215b and 216b of the housing base portion 21b are opposed to each other. It is only necessary to provide the flatness and level difference between the surface of the connecting portion 231b and the surface of the non-connecting portion 232b of the annular member 23b to be managed, and the number of management items for component accuracy can be reduced as in the first embodiment. There are advantages. As a result, the yield is improved.

  The difference between the present embodiment and the first embodiment is that, in the first embodiment, the throttle portion 233 opens toward the radially outer side, whereas in the present embodiment, the throttle portion 233b faces the radially inner side. It is in the point that is open. In the configuration of the actuator 1b according to the present embodiment, a seal part formed by the groove part 213 formed in the housing base part 21b, the exhaust hole 214, the outer cylinder part 112 of the rotor housing 10, and the inner cylinder part 211 of the stator housing 20b. 217, the configuration excluding the annular member 23b, and the throttle portion 233b formed by the housing base portion 21b and the annular member 23b are not limited to the configuration described above, but are other configurations. Is also applicable, and the arrangement of the components excluding the groove portion 213, the exhaust hole 214, the seal portion 217, the annular member 23, and the throttle portion 233 in the first embodiment, or the groove portion 213, the exhaust hole 214 in the second embodiment, Arrangement of components excluding the seal part 217, the annular member 23b, and the throttle part 233b, more specifically, the generation factor of dust generation Various bearing that, the linear guide mechanism, and in accordance with the arrangement of the ball screw may be to select the opening direction of the throttle portion.

(Modification)
FIG. 18 is a cross-sectional view schematically showing a configuration of an actuator according to a modification of the second embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 19 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the second embodiment shown in FIG. 18 as seen from the direction parallel to the rotation center. FIG. 20 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 19 as seen from the direction parallel to the rotation center. FIG. 21 is an enlarged view in a one-dot chain line frame in an actuator according to a modification of the second embodiment shown in FIG. In addition, the same code | symbol is attached | subjected to the same component as the actuator 1b which concerns on Embodiment 2 mentioned above, and the overlapping description is abbreviate | omitted.

  In the stator housing 20b of the actuator 1b according to the second embodiment described above, the surface of the annular member 23b facing the housing base portion 21b corresponds to the second gap 234 between the connection portion 231b and the non-connection portion 232b. In the stator housing 20c of the actuator 1c according to the modification of the second embodiment, as shown in FIGS. 18 to 21, a step is provided between the connection portion 231c and the non-connection portion 232c. Without providing, a step corresponding to the second gap 234 is provided between the surface 216c radially inside the inner diameter of the groove 213 of the housing base 21c and the surface 215c radially outer than the outer diameter of the groove 213, An aperture 233c is formed.

  The housing base portion 21c and the annular member 23c may be connected using, for example, a plurality of fastening members such as screws, as in the above-described example, or the housing base portion 21c and the annular member 23c may be connected to each other. The connection portion 231c may be bonded or welded.

  In this modified example, in order to manage the accuracy of the second gap 234 of the throttle portion 233c, the flatness and level difference of the surface 215c and the surface 216c of the housing base portion 21c, the surface 215c and the surface 216c of the housing base portion 21c, The flatness of the connecting portion 231c surface and the non-connecting portion 232c surface of the facing annular member 23c only needs to be provided as management items, and the advantage that the number of component accuracy management items can be reduced as in the above example. There is. As a result, the yield is improved.

(Embodiment 3)
FIG. 22 is a cross-sectional view schematically illustrating the configuration of the actuator according to the third embodiment by cutting along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 23 is a schematic diagram schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the second embodiment shown in FIG. 22 as seen from the direction parallel to the rotation center. FIG. 24 is a schematic diagram schematically showing a plane view of the annular member attached to the housing base portion shown in FIG. 23 via a connection member from a direction parallel to the rotation center. FIG. 25 is an enlarged view in the alternate long and short dash line frame in the actuator according to the third embodiment shown in FIG. In the example shown in FIG. 25, an example is shown in which the housing base 21d, the connection member 24, and the annular member 23d are connected using, for example, a fastening member 25 that is a screw. In addition, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the actuator 1d according to the third embodiment, the annular member 23d is attached via a connection member 24 as shown in FIGS.

  As shown in FIGS. 22 and 23, the stator housing 20d is substantially circular arranged on the other end side in the linear movement direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as an axis, as in the first embodiment. A plate-shaped housing base portion 21d, a substantially cylindrical inner cylinder portion 211 whose outer diameter is smaller than the inner diameter of the outer cylinder portion 112 of the rotor housing 10, and a substantially annular convex portion 212 to which the housing inner 22 is connected. A substantially annular groove portion 213 formed on the surface of the housing base portion 21d on the side of the inner cylinder portion 211 with the rotation center of the second rotor 40 as an axis, and a groove portion 213. A suction exhaust device that extends in one direction in the radial direction from the wall surface on the outer diameter side of the inner surface of the outer periphery of the rotor base 10 and is pierced through the housing base portion 21 and surrounded by the rotor housing 10 and the stator housing 20. And an exhaust hole 214 for sucking exhaust by 8. The surface 216d radially inward from the inner diameter of the groove portion 213 of the housing base portion 21d and the surface 215d radially outer than the outer diameter of the groove portion 213 are on the same plane having the same position in the linear motion direction.

  The inner cylindrical portion 211 extends in the linear motion direction from the radially outer end of the housing base portion 21 d and is formed on the radially inner side of the outer cylindrical portion 112 of the rotor housing 10. A seal portion 217 that overlaps the inner cylinder portion 211 of the housing base portion 21d in the radial direction with a first gap 218 of about 0.1 mm to 0.5 mm, for example, is formed.

  As shown in FIGS. 22 and 24, the annular member 23d is a substantially annular member whose inner diameter is smaller than the inner diameter of the groove portion 213 formed in the housing base portion 21d and whose outer diameter is larger than the outer diameter of the groove portion 213. It is. The connecting member 24 is a substantially annular member whose outer diameter is along the inner diameter of the groove portion 213 of the housing base portion 21d. The connecting member 24 is combined with the connecting member 24 interposed between the housing base portion 21d and the annular member 23d. In this case, the second gap between the annular member 23d and the outer surface 215d of the housing base 21d along the outer diameter of the groove portion 213 in the radial direction from the outer diameter of the groove portion 213 is, for example, about several μm to several tens of μm. The width in the linear motion direction is set so that a throttle portion 233d that overlaps in the linear motion direction across 234 is formed.

  In the example shown in FIG. 25, the housing base portion 21d, the connecting member 24, and the annular member 23d are connected using the fastening member 25 that is, for example, a screw. 24 and the annular member 23d may be connected, for example, by bonding or welding, as in the other embodiments described above.

  Further, when a screw or a bolt is used as the fastening member 25 that connects the housing base portion 21d, the connection member 24, and the annular member 23d, the connection member 24 is a member having the same number of plain washers as the screw or bolt. Also good.

  In the third embodiment, in order to manage the accuracy of the second gap 234 of the throttle portion 233d, the flatness of the surfaces 215d and 216d of the housing base portion 21d and the housing base portion 21d of the annular member 23d are opposed. The flatness of the surface, the flatness of the surface facing the housing base portion 21d of the connecting member 24, and the flatness of the surface facing the annular member 23d and the width in the linear motion direction may be provided as management items. Similar to the configuration, there is an advantage that the number of component accuracy management items can be reduced. As a result, the yield is improved.

  In the configuration of the actuator 1d according to the present embodiment, the groove 213 formed in the housing base portion 21d, the exhaust hole 214, the outer cylindrical portion 112 of the rotor housing 10, and the inner cylindrical portion 211 of the stator housing 20d are formed. The configuration excluding the seal portion 217, the annular member 23d, and the throttle portion 233d formed by the housing base portion 21d and the annular member 23d is not limited to the configuration described above, as in the first and second embodiments. Even other configurations are applicable.

(Modification)
FIG. 26 is a cross-sectional view schematically illustrating the configuration of an actuator according to a modification of the third embodiment, taken along a virtual plane including the rotation center of the first rotor and the rotation center of the second rotor. FIG. 27 is a schematic view schematically showing a plane of the housing base portion and the inner cylinder portion of the stator housing of the actuator according to the modification of the third embodiment shown in FIG. 26 when viewed from the direction parallel to the rotation center. FIG. 28 is a schematic view schematically showing a plane of the annular member attached to the housing base portion shown in FIG. 27 as seen from a direction parallel to the rotation center. FIG. 29 is an enlarged view in a one-dot chain line frame in an actuator according to a modification of the third embodiment shown in FIG. In the example shown in FIG. 29, the housing base portion 21e, the connection member 24a, and the annular member 23e are connected by using, for example, a fastening member 25 that is a screw, like the actuator 1d according to the third embodiment described above. An example is shown. In addition, the same components as those of the actuator 1d according to the third embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  In the actuator 1e according to the modification of the third embodiment, the annular member 23e is attached via a connection member 24a as shown in FIGS.

  As shown in FIGS. 26 and 27, the stator housing 20e is the other end in the linear motion direction of the ball screw shaft 15 with the rotation center of the second rotor 40 as the axis, similarly to the stator housing 20d according to the third embodiment described above. The substantially disc-shaped housing base portion 21e disposed on the side, the substantially cylindrical inner cylinder portion 211 whose outer diameter is smaller than the inner diameter of the outer cylinder portion 112 of the rotor housing 10, and the housing inner 22 are connected. An annular convex portion 212 and a substantially annular shape having an inner diameter larger than the outer diameter of the convex portion 212 and formed on the surface of the housing base portion 21 on the inner cylinder portion 211 side with the rotation center of the second rotor 40 as an axis. The groove portion 213 and the outer wall surface of the groove portion 213 extend in one radial direction and penetrate through the housing base portion 21e, so that the rotor housing 10 and the stator housing 2 And an exhaust hole 214 for sucking exhaust by the air inside the suction exhaust device 98 surrounded by the. The surface 216e radially inward from the inner diameter of the groove 213 of the housing base 21e and the surface 215e radially outer than the outer diameter of the groove 213 are on the same plane with the same position in the linear motion direction.

  The inner cylinder portion 211 extends in the linear motion direction from the radially outer end of the housing base portion 21 e and is formed on the radially inner side of the outer cylinder portion 112 of the rotor housing 10. A seal portion 217 is formed that overlaps with the inner cylinder portion 211 of the housing base portion 21e in the radial direction with a first gap 218 of about 0.1 mm to 0.5 mm, for example.

  As shown in FIGS. 27 and 29, the annular member 23e has an inner diameter smaller than the inner diameter of the groove portion 213 formed in the housing base portion 21e, like the annular member 23d according to the third embodiment described above. This is a substantially annular member having a diameter larger than the outer diameter of the groove 213. The connecting member 24a is a substantially annular member whose inner diameter is along the outer diameter of the groove portion 213 of the housing base portion 21e, and is combined with the connecting member 24a interposed between the housing base portion 21e and the annular member 23e. In this case, the annular member 23e and the surface 216e radially inward from the inner diameter of the groove portion 213 of the housing base portion 21e along the inner diameter of the groove portion 213 form a second gap 234 of about several μm to several tens μm, for example. The width in the linear motion direction is set so that the narrowed portion 233e that overlaps in the linear motion direction is formed.

  In the example shown in FIG. 29, the housing base portion 21e, the connecting member 24a, and the annular member 23e are connected using the fastening member 25 that is, for example, a screw. However, the housing base portion 21e and the connecting member are connected. Similarly to the actuator 1d according to the third embodiment, the 24a and the annular member 23e may be connected, for example, by bonding or welding.

  Also in this modified example, in order to manage the accuracy of the second gap 234 of the throttle portion 233e, the flatness of the surface 215e and the surface 216e of the housing base portion 21e and the housing base portion 21e of the annular member 23e are opposed. The flatness of the surface, the flatness of the surface facing the housing base portion 21e of the connecting member 24a, and the flatness of the surface facing the annular member 23e and the width in the linear motion direction may be provided as management items. Similar to the configuration, there is an advantage that the number of component accuracy management items can be reduced. As a result, the yield is improved.

  Further, when a screw or a bolt is used as the fastening member 25 that connects the housing base portion 21e, the connection member 24a, and the annular member 23e, the number of the connection member 24a is the same as that of the screw or bolt as in the third embodiment. A flat washer-shaped member may be used.

  The difference between the modified example of the third embodiment and the third embodiment is that, in the third embodiment, the throttle portion 233d is opened outward in the radial direction, whereas in this embodiment, the throttle portion 233e is in the radial direction. It is in the point opening toward the inside. In the configuration of the actuator 1e according to the modification of the third embodiment, the groove 213 formed in the housing base 21e, the exhaust hole 214, the outer cylinder 112 of the rotor housing 10, and the inner cylinder 211 of the stator housing 20e are formed. The configuration excluding the seal portion 217, the annular member 23e, the connecting member 24a, and the throttle portion 233e formed by the housing base portion 21e, the connecting member 24a, and the annular member 23e is the same as that of the third embodiment. The present invention is not limited to the above-described configuration, and other configurations can also be applied. In the third embodiment, components other than the groove portion 213, the exhaust hole 214, the seal portion 217, the annular member 23d, the connection member 24, and the throttle portion 233d are applicable. Arrangement or groove portion 213, exhaust hole 214, seal portion 217, annular member 23e, connection in modification of embodiment 3 Selection of the opening direction of the throttle part according to the arrangement of the constituent parts excluding the material 24a and the throttle part 233e, more specifically, the various bearings, the linear motion guide mechanism, the ball screw, etc. that cause dust generation You should do it.

  The actuator according to the above-described embodiment is used in a machine tool, a measuring device, a semiconductor manufacturing device, and a flat panel display manufacturing device, so that it is suitable for use in a clean environment, a measuring device, a semiconductor manufacturing device, It is possible to obtain a flat panel display manufacturing apparatus.

1, 1a, 1b, 1c, 1d, 1e Actuator 10 Rotor housing (rotating body)
11 Lid member 14A Flange portion 14B Linear motion transmission member 14C Fixing member 15 Ball screw shaft 20, 20a, 20b, 20c, 20d, 20e Stator housing 21, 21a, 21b, 21c, 21d, 21e Housing base portion 22 Housing inner 23, 23a , 23b, 23c, 23d, 23e Ring members 24, 24a Connection member 25 Fastening member 30 Stator 31 Stator core 32, 32A, 32B Excitation coil 35 Support member 36 Outer teeth 37 Back yoke 38 Inner teeth 39A Slit portion 40 Second rotor 41 , 51 Rotor core 42 Second rotor bracket 45 Support member 50 First rotor 52 Nut 53 First rotor bracket 54 Fixed member 61 Third bearing 62 Second bearing 63, 63A, 63B First bearing 71, 7 Angle detectors 72, 75 Resolver stator 73, 76 Resolver rotor 90 Control device 95 Support unit 96 Loading platform 97 Work 98 Suction / exhaust device 100 Actuator device 111 Plate portion 112 Outer cylinder portion 114 Guide rail 116 Slider 211 Inner cylinder portion 212 Convex portion 213 Groove 214 Exhaust hole 215, 215a, 215b, 215c, 215d, 215e Surface 216, 216a, 216b, 216c, 216d, 216e Surface 217 Seal portion 218 First gap 231, 231a, 231b, 231c, 231d Connection portion 232, 232a, 232b, 232c, 232d Non-connected portion 233, 233a, 233b, 233c, 233d, 233e Throttle portion 234 Second gap IT Inner circular arc OT Outer circular arc Zr, ZR Rotation center

Claims (16)

A stator comprising an exciting coil and a stator core;
A stator housing for fixing the stator;
A first rotor that is disposed radially inward of the stator and rotates relative to the stator;
A rod-shaped member disposed at the rotation center of the first rotor, and a screw shaft having a thread groove formed on at least a part of a surface thereof;
A nut that rotates with the first rotor and moves the screw shaft in a linear motion direction that is parallel to the rotation center of the first rotor;
A second rotor that is disposed radially outside the stator and rotates relative to the stator;
A rotor housing that rotates with the second rotor,
The rotor housing is
A substantially disk-shaped plate portion disposed on one end side in the linear movement direction of the screw shaft with the rotation center of the second rotor as an axis;
An outer cylinder portion extending in the linear motion direction from the radially outer end portion of the plate portion and formed on the radially outer side of the second rotor,
The stator housing is
A substantially disc-shaped housing base portion disposed on the other end side in the linear movement direction of the screw shaft with the rotation center of the second rotor as an axis;
A seal portion that extends from the radially outer end of the housing base portion in the linear motion direction and is formed on the radially inner side of the outer cylinder portion and overlaps the outer cylinder portion in the radial direction with a first gap therebetween. An inner cylinder portion to be
An exhaust hole formed in the housing base portion for sucking and exhausting air inside the rotor housing and the stator housing;
An actuator. The stator housing is
A substantially annular groove formed on a surface of the housing base portion on the inner tube portion side with the rotation center of the second rotor as an axis;
An inner diameter is smaller than an inner diameter of the groove portion, an outer diameter is larger than an outer diameter of the groove portion, and is a substantially annular member that covers the groove portion in a linear motion direction. An annular member that forms a throttle portion that overlaps the surface of the inner cylinder portion in the linear motion direction;
Further comprising
2. The actuator according to claim 1, wherein the exhaust hole extends in one radial direction from a wall surface on the outer diameter side of the groove and extends through the housing base.   3. The actuator according to claim 2, wherein the annular member includes a connection portion connected to the housing base portion along an inner diameter of the groove portion, and a non-connection portion not including the connection portion.   3. The actuator according to claim 2, wherein the annular member includes a connection portion connected to the housing base portion along an outer diameter of the groove portion, and a non-connection portion not including the connection portion.   5. The step of the annular member is provided with a step corresponding to the second gap between the connection portion and the non-connection portion on a surface facing the housing base portion. Actuator.   In the surface facing the annular member, the housing base portion is provided in the second gap between a surface radially inward of the inner diameter of the groove and a surface radially outer of the outer diameter of the groove. The actuator according to claim 3 or 4, wherein a corresponding step is provided.   The connecting member for connecting the annular member and the housing base portion along the inner diameter of the groove portion further includes a width in the linear motion direction corresponding to the second gap. Actuator.   The connecting member for connecting the annular member and the housing base portion along an outer diameter of the groove portion further includes a width in the linear motion direction corresponding to the second gap. 2. The actuator according to 2.   The actuator according to any one of claims 1 to 8, wherein the seal portion has a maximum width in the linear motion direction that is greater than a range of movement of the rotor housing in the linear motion direction. A first bearing that rotatably supports the first rotor with respect to the stator housing; and a second bearing that rotatably supports the second rotor with respect to the first rotor;
The actuator according to any one of claims 1 to 9, wherein the first bearing and the second bearing are rolling bearings or sliding bearings.   A first bearing that rotatably supports the first rotor with respect to the stator housing; and a second bearing that rotatably supports the second rotor with respect to the stator housing; The actuator according to any one of claims 1 to 9, wherein the second bearing is a rolling bearing or a sliding bearing. A flange portion fixed to the screw shaft; and a third bearing that rotatably supports the second rotor with respect to the flange portion,
The actuator according to claim 11, wherein the third bearing is a rolling bearing or a sliding bearing.   A machine tool comprising the actuator according to any one of claims 1 to 12.   A measuring apparatus comprising the actuator according to any one of claims 1 to 12.   A semiconductor manufacturing apparatus comprising the actuator according to claim 1.   The flat display manufacturing apparatus provided with the actuator of any one of Claims 1 thru | or 12.

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