JP5439663B2 - Electromagnetic actuator and joint device - Google Patents

Description

  The present invention relates to an electromagnetic actuator and a joint device that can be driven with multiple degrees of freedom.

  In recent years, a three-degree-of-freedom spherical electromagnetic actuator is known as an actuator that enables multi-degree-of-freedom driving. For example, Non-Patent Document 1 discloses a three-degree-of-freedom spherical electromagnetic actuator that can be driven in all directions on a spherical surface and is expected to be applied to driving a shoulder joint or eyeball of a robot.

  The electromagnetic actuator includes a mover and a stator that generates rotational torque about the mover around three axes (x-axis, y-axis, and z-axis). The mover includes four magnetic bodies divided along a circumferential direction parallel to the xy plane, and four permanent magnets inserted between these magnetic bodies at 90 ° intervals. The stator is disposed on the outer peripheral side of the mover via a predetermined air gap, and is divided into upper and lower parts along the z-axis direction. Each stator is formed of a magnetic material of the same material having six magnetic poles. By controlling the polarity of each magnetic pole, the movable element is rotated 360 ° around the z axis, the x axis and the y axis. Can be rotated around a predetermined angular range.

The Institute of Electrical Engineers of Japan LD-08-46 "Study on 3-DOF Spherical Electromagnetic Actuators" Toshihiro Kajima, Atsushi Yamamoto, Katsuhiro Hirata

  However, in the electromagnetic actuator having the above-described configuration, there is a limit on the rotation range of the mover about the x-axis and the y-axis. Therefore, when the mover is rotated beyond this limit, the mover returns to the initial position. There is an inconvenience that it cannot be restored.

  In particular, when the electromagnetic actuator is applied to a joint part of a transport robot or the like, it receives a moment resulting from the weight of the transported body or an external force applied to the arm, so that the x-axis, the y-axis, or a combination thereof is applied to the mover. A mechanical rotational torque acts around the shaft. When the mover rotates beyond the predetermined angle range due to this rotational torque, the mover may not be able to return to the return position by the electromagnetic torque generated by the stator. In this case, the intended function of the joint by the electromagnetic actuator cannot be performed, resulting in a malfunction of the transport robot.

  In view of the circumstances as described above, an object of the present invention is to provide an electromagnetic actuator and a joint device that can regulate the rotational movement of a mover caused by mechanical rotational torque.

  In order to achieve the above object, an electromagnetic actuator according to an embodiment of the present invention includes a mover, a stator, and a support mechanism.

  The mover has an output shaft. The stator generates a first electromagnetic torque centered on the output shaft and a second electromagnetic torque centered on an axis orthogonal to the output shaft, with respect to the mover. The support mechanism elastically supports rotational torque about an axis orthogonal to the output shaft that acts on the output shaft.

  The output shaft rotates around the output shaft by the first electromagnetic torque, and tilts by receiving a rotational force around an axis orthogonal to the output shaft by the second electromagnetic torque. The support mechanism elastically supports the rotational torque acting on the output shaft. Therefore, by setting the elastic force of the support mechanism to an appropriate value, it is possible to restrict or limit the tilting operation of the mover relative to the stator due to the mechanical rotational torque acting on the output shaft. In addition, the tilt angle of the mover can be controlled according to the magnitude of the rotational torque. Note that the output shaft may be formed integrally with the mover, or may be formed of a separate member from the mover.

  Further, the support mechanism supports not only the mechanical rotational torque acting on the output shaft but also the second electromagnetic torque generated by the magnetic interaction with the stator. Thereby, it becomes possible to position the mover at an arbitrary tilt angle position by utilizing a balance of forces between the second electromagnetic torque and the elastic force of the support mechanism. Further, based on the elastic force of the support mechanism, positioning of the movable element to an arbitrary tilt angle position can be realized by open loop control.

  The support mechanism may include a first support member, a second support member, and a coil spring. The first support member supports the output shaft. The second support member is attached to the stator. The coil spring is disposed concentrically with the output shaft between the first support member and the second support member.

  When the output shaft receives a rotational torque about an axial direction perpendicular thereto, the first support member tilts integrally with the output shaft. By the tilting of the first support member, a compressive force is applied to the coil spring. Therefore, the amount of tilt of the output shaft can be adjusted by setting the elastic force of the coil spring to an appropriate value. In addition, by pre-compressing the coil spring, it is possible to prevent the output shaft from tilting with respect to an external force equal to or less than the rotational torque corresponding to the compression force of the coil spring.

  The electromagnetic actuator may further include a support shaft including a spherical bearing that supports the mover.

  As a result, it is possible to stably and smoothly support the three-dimensional rotation of the mover.

  On the other hand, the support mechanism may include a bearing portion and a leaf spring. The bearing portion rotatably supports the output shaft. The leaf spring is bridged between the stator and the bearing portion.

  When the output shaft is tilted by receiving rotational torque about an axial direction perpendicular to the output shaft, the leaf spring is deformed, and an elastic force for returning the output shaft to the initial position appears. By setting the elastic force of the leaf spring to an appropriate value, the amount of tilt of the output shaft can be adjusted. In addition, it is possible to prevent the output shaft from tilting with respect to an external force equal to or less than the rotational torque corresponding to the mechanical force required for the deformation of the leaf spring.

  In the support mechanism having the above-described configuration, the mover is configured by first and second mover portions that are divided along the extending direction of the output shaft and are opposed to both main surfaces of the leaf spring via a gap. be able to. In this case, the stator can be constituted by first and second stator portions divided along the extending direction of the output shaft. The leaf spring can be configured to have a first end portion fixed between the first and second stator portions and a second end portion fixed to the bearing portion.

  Thereby, it becomes possible to implement | achieve the rotation control of the needle | mover about the axis | shaft orthogonal to an output shaft, without complicating the structure of a support mechanism.

  The electromagnetic actuator may further include an arm member attached to the output shaft.

  Thereby, for example, it is possible to configure a transport robot for transporting the transport target to a target position. In addition, it is possible to elastically support the mechanical rotational torque with respect to the mover due to the weight of the arm member and the load acting on the arm member by the support mechanism.

  Here, the mover can be composed of a plurality of magnetic bodies magnetized with alternating polarities in the circumferential direction. The stator can be composed of a first stator portion and a second stator portion. The first stator portion includes a plurality of first cores projecting toward the outer peripheral side of the mover, and a first electromagnetic coil wound around each of the plurality of first cores. The second stator portion includes a plurality of second cores protruding toward the outer peripheral side of the mover, and a second electromagnetic coil wound around each of the plurality of second cores, The first stator portion is laminated.

  With this configuration, it is possible to apply a first electromagnetic torque centered on the output shaft to the mover and a second electromagnetic torque centered on the axis orthogonal to the output shaft. Multi-degree-of-freedom driving is possible.

  A joint device according to one embodiment of the present invention includes a first member, a mover, a stator, a second member, and a support mechanism.

  The mover has an output shaft coupled to the first member. The stator is fixed to the second member, and with respect to the movable element, a first electromagnetic torque centered on the output shaft and a second centered on the axis orthogonal to the output shaft. The electromagnetic torque is generated. The support mechanism elastically supports a rotational torque about an axis orthogonal to the output shaft.

  The first member is rotated around the output shaft by the first electromagnetic torque. The first member is tilted by receiving a rotational force around an axis orthogonal to the output shaft by the second electromagnetic torque. The support mechanism elastically supports the tilting torque of the first member with respect to the second member. Therefore, by setting the elastic force of the support mechanism to an appropriate value, it is possible to restrict or limit the tilting operation of the mover relative to the stator due to the mechanical rotational torque acting on the output shaft. In addition, the tilt angle of the mover can be controlled according to the magnitude of the rotational torque.

  The first and second members include arm members and link levers of various robots to which the joint device is applied, and the shape and length thereof are not particularly limited.

  ADVANTAGE OF THE INVENTION According to this invention, the rotation operation | movement with respect to the stator of a needle | mover resulting from the mechanical rotational torque which acts on an output shaft can be controlled.

1 is a schematic configuration diagram of a transfer robot to which a joint device according to an embodiment of the present invention is applied. FIG. 6 is a plan view and a side view showing an example of operation of the transfer robot of FIG. 1. It is a sectional side view of the joint apparatus concerning one embodiment of the present invention. It is a whole perspective view of the actuator which constitutes the above-mentioned joint device. It is a schematic perspective view of the said actuator explaining the operating principle of the said actuator. It is a figure explaining the operating principle of the said actuator, (a) And (b) is a schematic side view of an actuator, (c) is a schematic plan view. (A) is a top view of the joint apparatus of FIG. 3, (b) is a top view of the electromagnetic actuator which comprises the said joint apparatus. It is a sectional side view explaining one effect | action of the said joint apparatus. It is a figure explaining the relationship between the tilt angle of the needle | mover of the said joint apparatus, and electromagnetic torque. It is a sectional side view of the joint apparatus which concerns on other embodiment of this invention. It is a top view of the leaf | plate spring member which comprises the support mechanism of the said joint apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)

  FIG. 1 is a perspective view showing a transport apparatus according to the first embodiment of the present invention. The illustrated conveying apparatus 100 includes a support shaft portion P and an articulated arm L. The multi-joint arm L includes a first arm member L1, a second arm member L2, and a third arm member L3. The first and second arm members L2 are constituted by link lever-type arms, and the third arm member L3 is constituted by a hand-type arm that holds a substrate W that is a transfer object. The substrate W is, for example, a semiconductor wafer, a glass substrate for display, or the like. The transfer apparatus 100 may be disposed in the vacuum processing chamber as a part of the substrate film forming unit, for example.

  2A is a plan view of the transport apparatus 100, and FIG. 2B is a side view of the transport apparatus 100. FIG. The support shaft portion P and the first arm member L1 are connected by the first drive portion D1, and the first arm member L1 and the second arm member L3 are connected by the second drive portion D2, and the second arm. The member L3 and the third arm member L3 are connected by a third drive unit D3. Each connection constitutes a joint part in which each member can relatively move (turn).

  The support shaft portion P is installed on a base (not shown) and supports the arm members L1 to L3 in a substantially horizontal posture. The support shaft portion P may also include a mechanism that moves up and down in the vertical direction (z-axis direction).

  The first drive unit D1 connects between the top of the support shaft part P and one end of the first arm member L1, and rotates the first arm member L1 with respect to the support shaft part P in the xy plane. A drive shaft is provided. The second driving unit D2 connects between the other end of the first arm member L1 and one end of the second arm member L2, and xy the second arm member L2 with respect to the first arm member L1. It has a drive shaft that turns in a plane. The third drive unit D3 connects between the other end of the second arm member L2 and one end of the third arm member L3. As will be described later, the third drive unit D3 has a function of rotating the third arm member L3 with respect to the second arm member L2 in the xy plane, and an axis parallel to the xy plane (hereinafter referred to as a horizontal axis). It is also composed of an electromagnetic actuator having a function of tilting the third arm member L3 around.

  The first drive unit D1 may include a first drive source that turns the first arm member L1 and a second drive source that turns the second arm member L2. In this case, the second drive unit D2 can be configured by a shaft (pulley) that transmits the driving force of the second drive shaft via a belt, a gear, or a link mechanism.

  The third arm member L3 may have a holding layer that holds the substrate W with a frictional force. In addition to this, the third arm member L3 may include a substrate holding mechanism such as a mechanical chuck mechanism, an electrostatic chuck mechanism, or a vacuum chuck mechanism.

  The transport apparatus 100 can rotate or extend / contract the articulated arm L in the xy plane by driving the first to third driving units D1 to D3 independently or synchronously. Accordingly, the substrate W can be supported by the third arm member L3 at an arbitrary position, or the substrate W can be transported to another arbitrary position. Further, as will be described later, the third drive unit D3 can tilt the third arm member L3 around the horizontal axis.

  Next, the configuration of the third drive unit D3 will be described. The third drive unit D3 is configured as a joint device that connects between the second arm member L2 and the third arm member L3.

  FIG. 3 is a side sectional view showing details of the drive unit D3. The third drive unit D3 includes a support mechanism D3S that elastically supports the third arm member L3, and an actuator D3M that rotates or tilts the third arm member L3.

  FIG. 4 is a perspective view of a main part of the actuator D3M. The actuator D3M includes a mover 1 and a stator 2. The mover 1 includes four permanent magnetic bodies 11 that are divided along the circumferential direction in the xy plane, and four permanent magnets inserted at equal pitches (90 ° intervals) between two adjacent magnetic bodies 11. And a magnet 12 (for example, residual magnetic flux density Br = 1.4T). That is, the mover 1 has two magnetic pole pairs in the circumferential direction. The permanent magnet 12 is magnetized in the direction of the arrow d.

  The stator 2 has a plurality of electromagnets 3 for driving the mover 1. These electromagnets 3 include a core 32 and a coil 31 wound around the core 32. Six electromagnets 3 are provided in each of the upper and lower stages. The plurality of upper electromagnets 3 and the plurality of lower electromagnets 3 are inner peripheral surfaces of the outer frame portions 21A and 21B of the stator 2 that are circumferentially shaped so as to protrude toward the outer peripheral side of the mover 1. It is attached to each side at an equal pitch (60 ° interval). The plurality of upper electromagnets 3 and the plurality of lower electromagnets 3 are arranged to correspond to each other so as to be symmetrical in the z-axis direction. The outer frame portions 21A and 21B are accommodated in a common stator case 20, and their relative positions are defined.

  The tip surface of the magnetic pole 321 that is the end portion of the core 32 faces the outer peripheral surface of the mover 1. Opposing surfaces of the mover 1 and the stator 2 are each cut into spherical surfaces and supported so as to have a predetermined gap (for example, 0.5 mm).

  The current supplied to each coil 31 can be controlled independently, and the amount of excitation in each of the 12 magnetic poles 321 can also be controlled independently. In the actuator D3M of this embodiment, four sets of coils 31 driven by three-phase (U, V, W) drive currents are configured. Which coil is driven in which phase can be arbitrarily set. The number of magnetic poles 321 is not limited to the above example, and can be set as appropriate according to the size of the actuator, the required rotational torque, and the like.

  In the actuator D3M, the stator 2 is disposed on the second arm member L2, the mover 1 is disposed on the third arm member L3, and the z-axis is in the vertical direction, and supports the third arm member L3. Via the mechanism D3S, the second arm member L2 is connected to be rotatable and tiltable.

  Next, the operating principle of the actuator D3M will be described with reference to FIGS. FIG. 5 is a perspective view for explaining the operating principle of the actuator D3M, and illustration of the coil 31 of the electromagnet 3 is omitted.

  First, the principle of operation for rotational movement around the x-axis will be described. FIG. 6A shows a cross section perpendicular to the x-axis shown in FIG. Here, four magnetic poles 321 exist in the cross section A. Further, the magnetic body 11 facing these four magnetic poles 321 exhibits S-pole magnetism depending on the magnetization direction of the permanent magnet 12.

  Now, when the coil 31 is excited so that the magnetic pole shown in FIG. 6A appears, the mover 1 can tilt by obtaining electromagnetic torque in the direction of the arrow in the figure. Further, when the current of the coil 31 is reversed, the mover 1 obtains electromagnetic torque in the direction opposite to that shown in FIG. The amount of torque in the rotation around the x axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32 existing in the cross section A.

  Note that when the amount of tilting of the mover 1 in the direction of the arrow in the figure becomes larger than a predetermined value, the electromagnetic torque acting on the mover 1 is weakened and the operation becomes unstable. Hereinafter, the rotation angle range of the movable element 1 exceeding the predetermined value is also referred to as “operation unstable region”. On the other hand, a rotation angle range in which the amount of tilt of the mover 1 is less than the predetermined value is set as an “operation stable region” of the mover 1.

  Next, the rotational movement around the y-axis will be described with reference to FIG. FIG. 6B shows a cross section obtained by rotating the cross section A by 60 ° around the z axis, that is, the cross section B or the cross section C. Here, also in the cross section B and the cross section C, the four magnetic poles 321 exist in the cross section. Further, the magnetic body 11 facing the four magnetic poles 321 exhibits N-pole magnetism depending on the magnetization direction of the permanent magnet 12.

  Now, when the coil 31 is excited so that the magnetic pole shown in FIG. 6B appears, the mover 1 can be tilted by obtaining electromagnetic torque in the direction of the arrow in the figure. Further, when the current of the coil 31 is reversed, the mover 1 obtains torque in the direction opposite to that in FIG. That is, if the same magnitude of torque is applied to both the cross section B and the cross section C by the same action, the resultant force acting on the mover becomes a rotational torque around the y axis. The amount of torque in the rotation around the y axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32 existing in the cross section B or C. Also in this case, there exists an “operation unstable region” of the mover 1 as described above.

  Finally, the operation principle of rotation around the z axis will be described with reference to FIG. FIG. 6C shows a cross-sectional view perpendicular to the z-axis. Now, when the coil 31 is excited so that the magnetic pole shown in FIG. 6C appears, the mover 1 can obtain electromagnetic torque in the direction of the arrow in the figure. If the same magnetic pole is generated for each of the two stators arranged along the z axis, no electromagnetic torque is generated on the axes other than the z axis. Further, when the current of the coil 31 is reversed, the mover 1 obtains electromagnetic torque in the opposite direction. The amount of torque in the rotation around the z axis can be controlled by adjusting the amount of current to the coil 31 wound around the core 32.

  The driving of the actuator D3M is controlled by a control unit (not shown) of the transport apparatus 100. This control unit can be composed of the same unit as the drive control system such as the other drive units D1 and D2.

  Furthermore, the transport apparatus 100 of the present embodiment includes a support shaft 4 that supports the mover 1 of the actuator D3M so as to be capable of rotating and tilting as described above. The support shaft 4 is a fixed shaft that extends in the z-axis direction and is connected to the second arm member L2. The support shaft 4 has a spherical bearing 41 attached to the center of the mover 1 at its upper end. Thereby, the mover 1 is rotated or tilted stably and smoothly.

  Subsequently, the support mechanism D3S constituting the third drive unit D3 will be described.

  FIG. 7A is a plan view of the drive unit D3 shown in FIG. 3, and FIG. 7B is a plan view when the support mechanism D3S is removed in FIG. 7A. The support mechanism D3S is for elastically supporting between the actuator D3M and the third arm member L3. The support mechanism D3S includes an upper support unit 5 (first support member), a coil spring 61, and a lower support unit 7 (second support member).

  The upper support unit 5 rotatably supports the drive shaft 8 (output shaft). The axis of the drive shaft 8 is arranged at the center of the mover 1. The lower end portion of the drive shaft 8 is fixed to a flange portion 81 that is integrally joined to the mover 1 of the actuator D3M, and the upper end portion of the drive shaft 8 is a pedestal portion 82 that supports the third arm member L3. It is fixed to. The upper support unit 5 is disposed between the annular member 51 that supports the upper end of the coil spring 61, the tubular member 53 that is fixed to the outer peripheral surface of the drive shaft 8, and the annular member 51 and the tubular member 53. Bearing member 52.

  The lower support unit 7 includes a disk member 71 that supports the lower end of the coil spring 61, and a pair of connecting members 72 that connect the disk member 71 to the stator 2 of the actuator D3M. The disc member 71 has a through hole 711 through which the drive shaft 6 is inserted at the center thereof. The through hole 711 has a hole diameter sufficiently larger than the shaft diameter of the drive shaft 8 and allows the drive shaft 8 to tilt over a predetermined angle range. As shown in FIGS. 7A and 7B, the connecting members 72 are fixed on the outer frame portion 21 </ b> A of the stator 2 so as to face each other with the drive shaft 8 interposed therebetween. The disc member 71 and the connecting member 72 are integrated using an appropriate fastener such as a bolt.

  The coil spring 61 is disposed concentrically with the drive shaft 8 between the upper support unit 5 and the lower support unit 7. By arranging the coil spring 61 concentrically with the drive shaft 8, an isotropic elastic restoring force can be obtained regardless of the tilting direction of the mover 1.

  The coil spring 61 is disposed in a compressed state. The magnitude of the pre-load applied to the coil spring 61 is set to a compressive load that can ensure the tilting operation of the drive shaft 8 by the electromagnetic torque of the actuator D3M, for example. Furthermore, the load is set such that the movable element 1 can regulate the rotation amount of the movable element 1 in the “operation stable region” with respect to a relatively large external force that can act on the arm member L3.

  In addition, the coil spring 61 is not restricted to the example arrange | positioned in a pre-load state. Further, instead of the coil spring 61, other elastic members can be employed. For example, a cylindrical rubber member or a coil molded body made of synthetic resin can be applied.

  In the transport device 100 of the present embodiment configured as described above, the third arm member L3 rotates by receiving electromagnetic torque around the drive shaft 8 by the third drive unit D3. In addition, the third arm member L3 is tilted by the actuator D3M in response to electromagnetic torque about an axis (x axis, y axis or their combined axis) orthogonal to the drive shaft 8. As a result, the transport apparatus 100 can perform the turning operation around the drive shaft 8 and the tilt operation with respect to the xy plane with respect to the substrate W supported by the third arm member L3.

  Here, in the actuator D3M having the above-described configuration, since the rotation range of the mover 1 around the x-axis and the y-axis is limited, the mover 1 rotates beyond the limit to the operation unstable region. In this case, the mover 1 may not be able to return to the initial position.

  In particular, in the present embodiment, the movable element 1 receives the moment caused by the weight of the substrate W that is the transported body and the excessive external force that acts on the arm member L3, so that the mover 1 has the x axis, the y axis, or a composite axis thereof. A mechanical rotational torque acts around. When the mover 1 rotates beyond the stable operation region to the unstable operation region due to the rotational torque, the mover 1 may not be returned to the return position by the electromagnetic torque generated by the stator 2. In this case, the intended function of the joint by the electromagnetic actuator cannot be performed, resulting in a malfunction of the transport robot.

  Therefore, the transport apparatus 100 of the present embodiment includes a support mechanism D3S. The support mechanism D3S elastically supports the tilting torque of the third arm member L3 with respect to the second arm member L2. Therefore, by setting the elastic support force by the support mechanism D3S to an appropriate value, the rotational operation of the mover 1 relative to the stator 2 due to the mechanical rotational torque acting on the drive shaft 8 is restricted or restricted. Is possible. Further, the rotation angle of the mover can be controlled according to the magnitude of the rotational torque.

  FIG. 8 is a principal side sectional view showing a state in which the third driving unit D3 receives a relatively large load P in the direction indicated by the arrow with respect to the third arm member L3. The mover 1 of the actuator D3M receives a mechanical torque (moment) caused by the load P via the drive shaft 8. Thereby, even when the stator 2 does not apply electromagnetic torque around the x axis to the mover 1, the mover 1 may tilt in the y-axis direction against the elastic force of the coil spring 1. is there. The amount of tilt of the mover 1 is determined by the size of the load P, the length of the drive shaft 8, the distance between the tilt center of the mover 1 and the point of action of the load P, and the like. At this time, the coil spring 61 generates a restoring force in a direction that cancels the compressive load applied by the upper support unit 5 and restricts the tilting of the movable element 1 beyond a predetermined level. As a result, the tilting of the mover 1 is stopped at a position where the mechanical torque acting on the mover 1 and the elastic force of the coil spring 61 are balanced. FIG. 8 shows a state where the mover 1 is stopped at a position inclined by the angle θ with respect to the drive shaft 8.

  As described above, the support mechanism D3S has a function of regulating the tilting of the drive shaft 8 and the mover 1. Therefore, according to this embodiment, even when a relatively large load P acts on the arm member L3, a large tilting operation of the mover 1 can be restricted. As a result, it is possible to avoid the tilting of the mover 1 to the “operation unstable region”, and by generating the required electromagnetic torque from the stator 2, the mover 1 can be stably returned to the initial horizontal position. To be able to.

  Further, according to the present embodiment, since the tilt angle of the mover 1 is determined by the balance position between the load P acting on the arm member L3 and the elastic force of the coil spring 61, if the tilt angle of the mover 1 is known, the stator It becomes possible to stably return the mover 1 to the original horizontal position by controlling the current to 1 (electromagnet 3) (FIG. 9).

  FIG. 9 is a diagram for explaining the above operation. As shown in FIG. 9A, consider a case where the drive shaft supported by a spring is driven and controlled by the actuator D3M. FIG. 9B shows the elastic force of the spring corresponding to the inclination angle of the arm and the load P when the load P is applied vertically upward (+ direction) and downward (− direction) to the arm. It shows the relationship with the amount of energization to the electromagnet necessary for canceling out. As is clear from FIG. 9B, the restoring force of the spring is generated regardless of which direction the load is applied to the arm.

  Therefore, it is necessary to return the arm to the horizontal position by detecting the arm tilt angle, drive shaft tilt angle, mover tilt angle, spring compression force, etc. electrically, mechanically or optically. The magnitude of the electromagnetic torque by the actuator, that is, the current values (i1, i2, i3,... [A]) supplied to the coils can be uniquely determined. The sensor for performing the detection may be built in the actuator D3M or may be arranged outside the actuator D3M.

  On the other hand, even when the arm is tilted at an arbitrary tilt angle from the horizontal position, the arm can be stably tilted at a desired tilt angle by supplying a current having a magnitude corresponding to the tilt angle to the electromagnet. It becomes possible. Furthermore, by preparing in advance a mapping showing the relationship between the tilt angle of the mover 1 and the coil current value, arm tilt angle control by open loop control can be realized. As a result, the control system of the actuator can be simplified and control can be facilitated.

(Second Embodiment)
FIG. 10 shows a third drive unit D3 ′ in the transport apparatus according to the second embodiment of the present invention. In the figure, parts corresponding to those in the first embodiment are given the same reference numerals. The drive unit D3 ′ includes an actuator D3M ′ and a support mechanism D3S ′.

  The actuator D3M ′ of the present embodiment includes a first movable part on the lower side in which the individual permanent magnets and magnetic materials constituting the movable element 1 are divided in the extending direction (z-axis direction) of the drive shaft 8, respectively. 1A and the upper-stage movable part 1B. A predetermined gap 1s is formed between the two movable parts 1A and 1B.

  The drive shaft 8 is integrated with the mover 1 via a fixed shaft portion 83 fixed to the center of the mover 1. The fixed shaft portion 83 is joined to the inner race portion 421 of the bearing member 42. The second movable part 1 </ b> B is supported by the inner race part 421 of the bearing member 42. The first mover portion 1 </ b> A is installed on a rotating disk 92 coupled around the fixed shaft portion 83.

The support mechanism D3S ′ includes a leaf spring member 62 that is bridged between the stator 2 and the fixed shaft portion 83 of the drive shaft 8. FIG. 11 is a plan view of the main part of the support mechanism D3S ′. The leaf spring member 62 includes an outer peripheral end portion 621 (first end portion) fixed between the outer frame portions 21A and 21B (first and second stator portions) of the stator 2 and the bearing member 42. And an inner peripheral end portion 622 (second end portion) fixed to the outer race portion 422.

  The leaf spring member 62 is fixed to the outer race portion of the bearing member 42 by being inserted into the gap 1s between the first movable portion 1A and the second movable portion 1B. The mover portions 1A and 1B are opposed to both main surfaces of the leaf spring member 62 through a gap, respectively. Thereby, the rotation operation of the mover 1 with respect to the leaf spring member 62 is ensured. The inner peripheral end portion 622 and the outer race portion 422 are connected via a connecting member 93. The connecting member 93 supports a sensor 91 that magnetically or optically detects the amount of rotation of the rotary disk 92. The sensor 91, the rotating disk 92, and the connecting member 93 constitute an angle detection mechanism 9 that detects the rotation angle of the mover 1.

  The leaf spring member 62 has a disc shape, and a plurality of arc-shaped openings or slits 623 are formed inside the surface. These slits 623 are intermittently formed in the circumferential direction, and connecting portions 624x and 624y for connecting the inner peripheral side region and the outer peripheral side region are respectively provided at the boundary portion. The connecting portion 624x allows the inner peripheral side of the leaf spring member 62 to be elastically deformed around the x axis with respect to the outer peripheral side, and the connecting portion 624y has the inner peripheral side of the leaf spring member 62 relative to the outer peripheral side. It can be elastically deformed around the y-axis. Thereby, the drive shaft 8 and the mover 1 can be tilted around the x-axis, the y-axis, and their combined axes with respect to the stator 2.

  In the drive unit D3 ′ of the present embodiment configured as described above, the mover 1 receives the electromagnetic torque from the stator 2 and rotates around the z axis and tilts around the x and y axes. Is possible. The mover 1 is composed of first and second mover portions 1A and 1B divided in the z-axis direction, and the leaf spring member 62 is disposed between them with a gap therebetween. Therefore, the rotation operation around the z-axis of the mover 1 is not hindered. Further, when the mover 1 is tilted, the leaf spring member 62 may be in contact with the first and second mover parts 1A and 1B, but not up and down so as not to contact the stator 2 (electromagnet 3). The distance between the electromagnet 3 of each stator and the leaf spring member 62 is defined.

  In the present embodiment, the mechanical torque around the horizontal axis acting on the drive shaft 8 and the mover 1 is supported by the elastic force of the leaf spring member 62. Therefore, as in the first embodiment described above, the amount of rotation of the mover 1 by the mechanical torque is restricted by the elastic restoring force of the leaf spring member 62, and the tilting operation of the mover 1 reaching the unstable operation region is performed. It can be avoided. Thereby, the stable drive control of the drive part D3 'can be ensured. The elastic force of the leaf spring member 62 can be arbitrarily adjusted according to the width, length, number, position, etc. of the thickness slit 623 of the spring material.

Further, according to the present embodiment, the tilt angle control of the mover 1 using the elastic force of the support mechanism D3S ′ can be performed stably and easily as in the first embodiment described above. The tilt angle control of the mover 1 may be performed by open loop control or feedback control. In the latter case, the angle detection mechanism 9 can also be used as the tilt angle sensor of the mover 1.

  In the present embodiment, the plate spring member 62 constituting the support mechanism D3S ′ is not limited to a disk shape. For example, it is also possible to use a plurality of strip-like leaf spring members that extend radially from the drive shaft 8 side toward the outer stator 2 side.

  As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.

  For example, in the above embodiment, the example in which the electromagnetic actuator and the joint device according to the present invention are applied to the third drive unit D3 of the transport device 100 has been described, but the first and second drive units D1 and D2 are also applied. A similar structure can be applied.

  Further, the present invention is not limited to the joint portion of the transfer robot, and the present invention can be applied to joint devices and driving sources of various robots that involve rotation and tilting operations such as a welding robot and a monitoring camera.

DESCRIPTION OF SYMBOLS 1 Movable element 1A, 1B Movable element part 2 Stator 3 Electromagnet 4 Support shaft 5 Upper support unit (equivalent to a 1st support member)
7 Lower support unit (equivalent to the second support member)
8 Drive shaft (equivalent to output shaft)
DESCRIPTION OF SYMBOLS 11 Magnetic body 12 Permanent magnet 31 Coil 32 Core 41 Spherical bearing 61 Coil spring 62 Leaf spring member 100 Conveyance apparatus D1-D3 Drive part L1-L3 Arm part D3M, D3M 'Actuator D3S, D3S' Support mechanism

Claims (8)

A mover having an output shaft;
A stator for generating a first electromagnetic torque centered on the output shaft and a second electromagnetic torque centered on the axis orthogonal to the output shaft, with respect to the mover;
An electromagnetic actuator comprising: an elastic member that is concentrically arranged with the output shaft, and a support mechanism that acts on the output shaft and supports rotational torque about an axis orthogonal to the output shaft. The electromagnetic actuator according to claim 1,
The support mechanism is
A first support member that pivotally supports the output shaft;
A second support member attached to the stator;
An electromagnetic actuator having a coil spring as the elastic member disposed concentrically with the output shaft between the first support member and the second support member. The electromagnetic actuator according to claim 2,
An electromagnetic actuator further comprising a support shaft including a spherical bearing that supports the mover. A mover having an output shaft;
A stator for generating a first electromagnetic torque centered on the output shaft and a second electromagnetic torque centered on the axis orthogonal to the output shaft, with respect to the mover;
A support mechanism that elastically supports rotational torque about an axis orthogonal to the output shaft that acts on the output shaft ;
The support mechanism is
A bearing portion for rotatably supporting the output shaft;
An electromagnetic actuator having an elastic member spanned between the stator and the bearing portion. The electromagnetic actuator according to claim 4,
The mover includes first and second mover portions that are divided along the extending direction of the output shaft and are opposed to both main surfaces of the leaf spring as the elastic member via a gap,
The stator has first and second stator parts divided along the extending direction of the output shaft,
The said leaf | plate spring is an electromagnetic actuator which has the 1st end part fixed between the said 1st and 2nd stator part, and the 2nd end part fixed to the said bearing part. The electromagnetic actuator according to any one of claims 1 to 5,
An electromagnetic actuator further comprising an arm member attached to the output shaft. The electromagnetic actuator according to any one of claims 1 to 6,
The mover has a plurality of magnetic bodies magnetized with alternating polarities in the circumferential direction,
The stator is
A first stator portion including a plurality of first cores projecting toward the outer peripheral side of the mover, and a first electromagnetic coil wound around each of the plurality of first cores;
A plurality of second cores projecting toward the outer peripheral side of the mover; and a second electromagnetic coil wound around each of the plurality of second cores, and laminated on the first stator portion An electromagnetic actuator having a second stator portion. A first member;
A second member;
A mover having an output shaft coupled to the first member;
A first electromagnetic torque centered on the output shaft and a second electromagnetic torque centered on the axis orthogonal to the output shaft is generated for the mover fixed to the second member. A stator to let
A joint device comprising: an elastic member disposed concentrically with the output shaft, and a support mechanism that acts on the output shaft and supports a rotational torque about an axis orthogonal to the output shaft.