JP2014075954A - Rotation driving device, robot device and exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation driving device which can efficiently perform rotation driving.SOLUTION: A rotation driving device comprises: a rotation axis 2 which is rotatably supported; a rotor 3 which includes a hole portion 3A having a larger diameter than that of the rotation axis 2 to have the rotation axis 2 penetrated through the hole portion 3A, and which rotates the rotation axis 2 around an axis line by revolving the rotor around the rotation axis 2 in a state that enables drive power to transmit between an inner peripheral surface of the hole portion 3A and an outer peripheral surface of the rotation axis 2; and a displacement drive unit 7 which is disposed at the position surrounding the rotor 3, and which displaces and drives the rotor 3 along at least two directions X, Y crossing each other in a plane orthogonal to the rotation axis 2. The displacement drive unit 7 includes: driving elements 5a-5d which vibrate in directions parallel to the displacement directions X, Y of the rotor 3; and coupling members 6a-6d which connect the driving elements 5a-5d with the rotor 3, which are elastically deformable between the driving elements 5a-5d and the rotor 3.

Description

  The present invention relates to a rotary drive device, a robot apparatus, and an exposure apparatus.

  Conventionally, a driving device such as an ultrasonic motor using a piezoelectric element (also referred to as a piezoelectric element) is known. For example, in a driving device using a piezoelectric element, a driving voltage is applied to the piezoelectric element, and the vibrating body is vibrated against the driven body while the vibrating body is vibrated by the piezoelectric element. There are those that rotate or linearly drive the body (see, for example, Patent Documents 1 and 2).

JP-A-7-9266 Japanese Patent Laying-Open No. 2005-6393

By the way, in the drive device described above, a d ₃₃ mode piezoelectric element as shown in FIG. 5A or a d ₁₅ mode piezoelectric element as shown in FIGS. 5B and 5C is used.

Among these, as shown in FIG. 5A, the d ₃₃ mode piezoelectric element undergoes thickness deformation that occurs in the piezoelectric body when a drive voltage (electric field) is applied in a direction parallel to the polarization direction of the piezoelectric body. It is used. The piezoelectric element of the d ₃₃ mode, by applying a driving voltage of one polarity (positive), it is possible to deform the piezoelectric element in the extension direction. On the other hand, in the piezoelectric element of the d ₃₃ mode, the other when applying the driving voltage polarity (negative), since the polarization direction and the opposite direction, smaller than a positive drive voltage so that the polarization characteristic is not extinguished (Including zero (0)).

In contrast, the piezoelectric element of d ₁₅ mode, upon application of a polarization direction perpendicular to the driving voltage of the piezoelectric body (electric field), is obtained by utilizing the shearing deformation generated in the piezoelectric body. The piezoelectric element of the d ₁₅ mode, as shown in FIG. 5 (b), by applying a driving voltage of one polarity (positive), be shear deformation toward the piezoelectric body on one side of the shear direction Is possible. On the other hand, in the piezoelectric element of the d ₁₅ mode, as shown in FIG. 5 (c), by applying the other of the drive voltage polarity (negative), to shear deformation toward the piezoelectric body on the other side of the shear direction It is possible.

Therefore, the d ₃₃ mode piezoelectric element is vibrated only by deformation in the extension direction while applying a drive voltage of one polarity (plus), whereas the d ₁₅ mode piezoelectric element is vibrated in both polarities ( It is possible to vibrate greatly toward both sides in the shearing direction while applying a sinusoidal driving voltage (AC voltage) having plus / minus).

Thus, the d ₁₅ mode piezoelectric element has a characteristic that the displacement amount with respect to the drive voltage can be increased. Furthermore, the d ₁₅ mode piezoelectric element that vibrates in the shearing direction is more advantageous for downsizing (particularly thinning) than the d ₃₃ mode piezoelectric element that vibrates in the extending direction.

However, in the conventional driving apparatus are often those using a piezoelectric element d ₃₃ mode, the piezoelectric element of the d ₁₅ mode, but there is used in combination with a piezoelectric element of d ₃₃ mode, d ₁₅ as described above There is no one that efficiently drives the driven body by effectively utilizing the characteristics of the mode.

  In view of the circumstances as described above, it is an object of the present invention to provide a rotary drive device capable of efficiently performing a rotary drive, and a robot apparatus and an exposure apparatus using such a rotary drive device.

  According to the first aspect of the present invention, the rotating shaft that is rotatably supported and the hole portion having a diameter larger than the rotating shaft are passed through the rotating shaft. In a state where the driving force can be transmitted between the inner peripheral surface and the outer peripheral surface of the rotating shaft, by rotating around the rotating shaft, the rotor that rotates the rotating shaft around the axis and the position surrounding the rotor A displacement drive unit that is disposed and that drives the rotor to be displaced in at least two intersecting directions within a plane orthogonal to the rotation axis, and the displacement drive unit includes a drive element that vibrates in a direction parallel to the direction in which the rotor is displaced. There is provided a rotary drive device characterized in that the drive element and the rotor are connected to each other, and a connecting member elastically deformable between the drive element and the rotor is provided.

  Further, according to the second aspect of the present invention, there is provided a robot apparatus including an actuator using the rotation driving device according to the first aspect of the present invention and an arm mechanism that is driven and controlled by the actuator.

  According to the third aspect of the present invention, there is provided an exposure apparatus including an actuator using the rotary drive device according to the first aspect of the present invention and a stage mechanism that is driven and controlled by the actuator.

  According to the present invention, it is possible to provide a rotation driving apparatus that can efficiently perform rotation driving, and a robot apparatus and an exposure apparatus using such a driving apparatus.

It is a schematic diagram which shows schematic structure of the rotational drive apparatus which concerns on 1st Embodiment. It is a schematic diagram for demonstrating operation | movement of the rotational drive apparatus which concerns on the said 1st Embodiment. It is a side view which shows schematic structure of the robot apparatus which concerns on 2nd Embodiment. It is a side view which shows schematic structure of the exposure apparatus which concerns on 3rd Embodiment. It is a schematic view for explaining a piezoelectric element d ₃₃ mode and the d ₁₅ mode.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings used in the following description, in order to make the features easy to understand, there are cases in which the portions that become the features are schematically shown for convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

(First embodiment)
First, a rotary drive device 1 shown in FIG. 1 will be described as a first embodiment.
FIG. 1 is a schematic diagram showing a schematic configuration of the rotary drive device 1.

  As shown in FIG. 1, the rotary drive device 1 includes a rotary shaft 2, a rotor 3 having a hole 3 </ b> A that penetrates the rotary shaft 2, a frame 4 surrounding the rotor 3, and a rotor 3 of the frame 4. A plurality of drive elements 5a to 5d attached to opposing surfaces and a plurality of connection members 6a to 6d for connecting the plurality of drive elements 5a to 5d and the rotor 3 are roughly provided.

  The rotating shaft 2 consists of a round shaft. The rotary shaft 2 is supported so as to be rotatable about an axis via a bearing (not shown).

  The rotor 3 is formed of a rectangular parallelepiped member that forms a square when viewed from the axial direction. The hole 3 </ b> A is a round hole having a diameter larger than that of the rotating shaft 2, and is provided so as to penetrate the central part of the rotor 3 in the axial direction. And the rotating shaft 2 is arrange | positioned inside this hole 3A.

  The frame 4 is made of a frame-shaped member that forms a square when viewed from the axial direction. The rotor 3 is disposed inside the frame 4.

  The plurality of drive elements 5a to 5d and the connecting members 6a to 6d are arranged between the frame 4 that is a fixed portion and the rotor 3 that is a movable portion. The plurality of drive elements 5a to 5d and the connecting members 6a to 6d have two directions orthogonal to each other in a plane orthogonal to the rotation axis 2 of the rotor 3 with respect to the frame 4, that is, the X direction shown in FIG. The displacement driving unit 7 is configured to drive the displacement in one direction) and the Y direction (the other direction).

  Specifically, the displacement drive unit 7 includes a first drive element 5a arranged along a surface 4a on one side in the Y direction among the four surfaces facing the rotor 3 of the frame 4, and the other in the Y direction. The second drive element 5b disposed along the surface 4b on the side, the third drive element 5c disposed along the surface 4c on the one side in the X direction, and the surface 4d on the other side in the X direction. And a fourth driving element 5d.

These first to fourth driving elements 5a to _5d, a piezoelectric element of _{d 15} mode is used. The piezoelectric element of the d ₁₅ mode, by applying a sine-wave driving voltage (AC voltage) having both polar (plus / minus), it is possible to vibrate toward both sides of the shear direction.

  The first and second drive elements 5a and 5b constitute one drive element that vibrates in the X direction in synchronization with each other at positions facing each other across the rotor 3. That is, the first drive element 5a and the second drive element 5b are arranged along the surfaces 4a and 4b on both sides in the Y direction of the frame 4 so that the respective shear directions are parallel to the X direction. Yes.

  On the other hand, the third and fourth drive elements 5c and 5d constitute the other drive element that vibrates in the Y direction while being synchronized with each other at positions facing each other with the rotor 3 interposed therebetween. That is, the third drive element 5c and the fourth drive element 5d are arranged along the surfaces 4a and 4b on both sides in the X direction of the frame 4 so that the respective shear directions are parallel to the Y direction. Yes.

  The first to fourth drive elements 5a to 5d are arranged in a plurality (two in the present embodiment) in the circumferential direction of the frame 4 on the respective surfaces 4a to 4d. Further, first to fourth plates 8a to 8d are attached to the surfaces of the first to fourth drive elements 5a to 5d, respectively. These first to fourth plates 8a to 8d are supported by a plurality of drive elements 5a to 5d disposed on the respective surfaces 4a to 4d. Note that the number of the drive elements 5a to 5d disposed on the respective surfaces 4a to 4d is not particularly limited, and is not limited to the above-described plural cases, and may be one.

  Of the four surfaces facing the frame 4 of the rotor 3, the displacement drive unit 7 includes a first connecting member 6a for connecting the surface 3a on one side in the Y direction and the plate 8a, and the other side in the Y direction. A second connecting member 6b that connects the surface 3b and the plate 8b, a third connecting member 6c that connects the surface 3c on one side in the X direction and the plate 8c, and a second connecting member 6c on the other side in the Y direction. A fourth connecting member 6d that connects the surface 3d and the plate 8d is provided.

  These first to fourth connecting members 6 a to 6 d are made of spring members (elastic members), and are arranged in a state where they can be expanded and contracted (elastically deformed) between the plates 8 a to 8 d and the rotor 3.

Next, the operation of the rotary drive device 1 will be described with reference to FIGS.
2A to 2D are schematic diagrams for explaining the operation of the rotary drive device 1.

  In the rotary drive device 1, when no drive voltage (AC voltage) is applied, the inner peripheral surface of the hole 3 </ b> A of the rotor 3 is not in contact with the outer peripheral surface of the rotating shaft 2 as shown in FIG. 1. It has become.

  In the rotary driving device 1, when a driving voltage (AC voltage) is applied, a driving voltage (AC voltage) having an opposite phase is applied between the first driving element 5a and the second driving element 5b. At the same time, a driving voltage (AC voltage) having an opposite phase is applied between the third driving element 5c and the second driving element 5d.

  Thereby, in the rotational drive device 1, the first drive element 5a and the second drive element 5b are vibrated in the X direction while being synchronized with each other at positions facing each other across the rotor 3. The third driving element 5c and the fourth driving element 5d can be vibrated in the Y direction while being synchronized with each other.

  In the rotary drive device 1, the phase of the drive voltage (AC voltage) is shifted by 90 ° between the first drive element 5 a and the third drive element 5 c. Similarly, the phase of the drive voltage (AC voltage) is shifted by 90 ° between the second drive element 5b and the fourth drive element 5d.

  In this case, as shown in the order of FIGS. 2A to 2D, the outer peripheral surface of the rotating shaft 2 and the hole portion according to the difference in the displacement amount in the shear direction that changes between the drive elements 5 a to 5 d. The rotor 3 can be turned (revolved) about the rotating shaft 2 in a state in which the inner peripheral surface of 3A is in frictional contact. In the rotary drive device 1, the rotary shaft 2 can be driven to rotate in the direction opposite to the rotor 3 while transmitting a driving force from the rotor 3 to the rotary shaft 2.

  Moreover, in the said rotational drive apparatus 1, it is preferable to vibrate the said 1st thru | or 4th contacts 5a-5d at the resonance point. Thereby, it is possible to drive the rotating shaft 2 more efficiently.

  In the rotation drive device 1, the rotation shaft 2 can be driven to rotate in the opposite direction by setting the phase of the drive voltage (AC voltage) applied to each of the drive elements 5a to 5d in the opposite direction. is there.

  Moreover, in the said rotational drive apparatus 1, while the said rotating shaft 2 is rotating, the outer periphery of the rotating shaft 2 is made by making the drive voltage (alternating current voltage) applied to each drive element 5a-5d non-apply. The inner peripheral surface of the hole 3A of the rotor 3 can be brought into a non-contact state with respect to the surface, and the rotary shaft 2 can be rotated with inertia.

(Second Embodiment)
Next, a robot apparatus 100 shown in FIG. 3 will be described as a second embodiment.
FIG. 3 is a side view showing a schematic configuration of the robot apparatus 100.

  As shown in FIG. 3, the robot device 100 includes a terminal node portion 101, a middle node portion 102, and a joint portion 103 as arm mechanisms, and the terminal node portion 101 and the middle node portion 102 are interposed via the joint portion 103. Connected to each other. The joint portion 103 is provided with a shaft support portion 103a and a shaft portion 103b. The shaft support portion 103 a is fixed to the middle joint portion 102. The shaft portion 103b is supported in a state of being fixed by the shaft support portion 103a.

  The end node portion 101 includes a connecting portion 101a and a gear 101b. The shaft portion 103b of the joint portion 103 is penetrated through the connecting portion 101a, and the end node portion 101 is rotatable with the shaft portion 103b as a rotation axis. The gear 101b is a bevel gear fixed to the connecting portion 101a. The connecting portion 101a rotates integrally with the gear 101b.

  The middle joint portion 102 includes a housing 102a and an actuator ACT. The rotary drive device 1 can be used for the actuator ACT. The actuator ACT is provided in the housing 102a. A rotary shaft member 104a is attached to the actuator ACT. A gear 104b is provided at the tip of the rotating shaft member 104a. The gear 104b is a bevel gear fixed to the rotating shaft member 104a. The gear 104b is in mesh with the gear 101b.

  In the robot apparatus 100 having the above-described configuration, the rotation shaft member 104a rotates by driving the actuator ACT, and the gear 104b rotates integrally with the rotation shaft member 104a.

  The rotation of the gear 104b is transmitted to the gear 101b meshed with the gear 104b, and the gear 101b rotates. As the gear 101b rotates, the connecting portion 101a also rotates, whereby the end node portion 101 rotates about the shaft portion 103b.

  In the robot apparatus 100, by using the rotary drive device 1 for the actuator ACT, the end node portion 101 can be directly rotated without using, for example, a speed reducer. Furthermore, since the robot apparatus 100 has a configuration capable of efficiently transmitting a driving force, stable operation can be performed.

(Third embodiment)
Next, an exposure apparatus 200 shown in FIG. 4 will be described as a third embodiment.
FIG. 4 is a side view showing a schematic configuration of the exposure apparatus 200.

  The exposure apparatus 200 performs exposure on a moving stage (stage mechanism) 201 on which a wafer (not shown) to be exposed is placed, and on the wafer placed on the moving stage 201. The optical system 202 is roughly provided.

  The moving stage 201 can move and operate the wafer in at least two directions orthogonal to each other in the plane, and the rotary driving device 1 can be used for the actuator ACT that drives the moving stage 201.

  In the exposure apparatus 200, the rotary drive device 1 is used as the actuator ACT, so that the wafer placed on the moving stage 201 can be moved. Further, since the exposure apparatus 200 is configured to be able to efficiently transmit driving force, a stable moving operation can be performed.

  The present invention is not necessarily limited to the first to third embodiments, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the driving device 1, the first driving element 5a and the third driving element 5c, and the second driving element 5b and the fourth driving element 5d, Although the phase of the drive voltage (AC voltage) is shifted by 90 °, the present invention is not necessarily limited to this case. That is, the phase of the drive voltage (alternating voltage) can be shifted within a range in which the rotor 3 can be swung (revolved).

  The displacement driving unit 7 is configured to drive the rotor 3 in two directions orthogonal to each other in a plane orthogonal to the rotation shaft 2, but is not necessarily limited to such a configuration. Instead, any configuration may be used as long as the rotor 3 is driven to be displaced in at least two intersecting directions within a plane orthogonal to the rotation shaft 2.

  Further, the drive device 1 has a configuration in which the displacement drive unit 7 is disposed between the rotor 3 and the frame 4 that form a square (regular tetragon) when viewed from the axial direction. Although not necessarily limited, for example, the displacement driving unit 7 may be arranged between the frame 3 and the rotor 3 that forms a regular polygon such as a regular triangle, a regular pentagon, a regular hexagon, or a regular octagon. It is.

  That is, in the displacement drive unit 7, it is possible to increase the number of drive elements and apply the drive voltage (AC voltage) with a phase difference between the drive elements. Generally, when the number of drive elements is increased, it is necessary to increase the number of drivers (amplifiers) for driving the drive elements. However, in the rotary drive device 1 to which the present invention is applied, the first and second The vibrations of the three driving elements 5a and 5c and the second and fourth driving elements 5b and 5d are synchronized with each other while a driving voltage (AC voltage) having an opposite phase is applied. Therefore, in this case, each of the drive elements 5a to 5d can be driven efficiently without increasing the number of drivers (amplifiers), so that the cost is very low.

  Further, in the rotary drive device 1, a plurality of the rotor 3 and the displacement drive unit 7 may be arranged side by side in the axial direction of the rotary shaft 2. In this case, it is possible to further increase the driving force for the rotating shaft 2 by increasing the number of the rotors 3 and the displacement driving units 7.

  Further, the rotary drive device 1 is configured to transmit the driving force from the rotor 3 to the rotary shaft 2 by frictional contact between the outer peripheral surface of the rotary shaft 2 and the inner peripheral surface of the hole 3A. However, it is not necessarily limited to such a configuration. That is, if the driving force can be transmitted between the outer peripheral surface of the rotating shaft 2 and the inner peripheral surface of the hole 3A, for example, the external teeth provided on the outer peripheral surface of the rotating shaft 2 and the hole 3A It is also possible to adopt a configuration in which a driving force is transmitted from the rotor 3 to the rotary shaft 2 in a state where the inner teeth provided on the inner peripheral surface of the rotor 3 are engaged.

  Further, in the rotary drive device 1, the phase of the drive voltage (AC voltage) applied to the drive elements 5 a to 5 d is reversed while the rotary shaft 2 is rotating, so that the rotary shaft 2 is reversed. It is possible to decelerate or stop the rotation of the rotating shaft 2 in a state in which the outer peripheral surface of the shaft and the inner peripheral surface of the hole 3A are in frictional contact. It is also possible to adopt a configuration in which a brake mechanism for stopping is separately provided.

  Further, in the rotary drive device 1, the rotary shaft 2 is arranged inside the hole 3 </ b> A in a state in which the central axes thereof coincide with each other, so that when the drive voltage (alternating voltage) is not applied, the rotary shaft 2. Although the inner peripheral surface of the hole 3A of the rotor 3 is in a non-contact state with respect to the outer peripheral surface, the configuration is not necessarily limited to such a configuration.

  For example, by disposing the rotating shaft 2 inside the hole 3A with the mutual center axes being shifted, the rotor with respect to the outer peripheral surface of the rotating shaft 2 even when no driving voltage (AC voltage) is applied. It is possible to make it the state which the inner peripheral surface of 3 hole part 3A contacted. In this case, when the drive voltage (AC voltage) is not applied, the stopped state of the rotating shaft 2 can be maintained.

As for the driving elements 5a to 5d, although the piezoelectric element d ₁₅ mode is preferably used, as long as it vibrates in the direction parallel to the direction in which the rotor 3 is displaced, in addition piezoelectric element described above However, for example, an electrostrictive element or a magnetostrictive element can also be used.

  Furthermore, the rotation drive device 1 can be widely used as a drive source for various purposes other than the actuator ACT provided in the robot device 100 and the exposure device 200.

  DESCRIPTION OF SYMBOLS 1 ... Rotary drive device 2 ... Rotating shaft 3 ... Rotor 3A ... Hole 4 ... Frame 5a ... 1st drive element 5b ... 2nd drive element 5c ... 3rd drive element 5d ... 4th drive element 6a ... 1st DESCRIPTION OF SYMBOLS 1 Connection member 6b ... 2nd connection member 6c ... 3rd connection member 6d ... 4th connection member 7 ... Displacement drive part 8a-8d ... Plate 100 ... Robot apparatus ACT ... Actuator 200 ... Exposure apparatus 201 ... Moving stage (Stage mechanism)

Claims (12)

A rotating shaft supported rotatably,
A hole having a diameter larger than that of the rotation shaft is provided, and the rotation shaft passes through the hole, and a driving force is transmitted between the inner peripheral surface of the hole and the outer peripheral surface of the rotation shaft. In a possible state, a rotor that revolves around the axis of rotation by revolving around the axis of rotation;
A displacement drive unit that is disposed at a position surrounding the periphery of the rotor and that drives the rotor to be displaced in at least two intersecting directions within a plane orthogonal to the rotation axis;
The displacement drive unit includes a drive element that vibrates in a direction parallel to a direction in which the rotor is displaced, and a connecting member that connects the drive element and the rotor.   The displacement drive unit includes a drive element on one side that vibrates in a direction parallel to one direction in which the rotor is displaced, and a drive element on the other side that vibrates in a direction parallel to the other direction in which the rotor is displaced. The rotation drive device according to claim 1, wherein the rotor is revolved around the rotation axis by shifting a phase of vibration between the rotation shafts.   The rotary drive device according to claim 2, wherein a phase difference of vibration between the one side drive element and the other side drive element is 90 °.   The rotation driving device according to claim 1, wherein the displacement driving unit drives the rotor to be displaced in two directions orthogonal to each other within a plane orthogonal to the rotation axis. The driving element on one side and / or the driving element on the other side has a configuration in which a pair of driving elements are arranged at positions facing each other across the rotor,
5. The rotation according to claim 2, wherein the pair of driving elements vibrate in one direction in which the rotor is displaced or in a direction parallel to the other direction while being synchronized with each other. Drive device.   The drive element on the one side and / or the drive element on the other side has a configuration in which a plurality of drive elements are arranged side by side in one direction in which the rotor is displaced and / or in a direction parallel to the other direction. The rotation drive device according to any one of claims 1 to 5. Wherein the driving element, the rotary drive device according to any one of claims 1 to 6, characterized in that a piezoelectric element which vibrates at a d ₁₅ mode.   The rotational driving apparatus according to claim 1, wherein the driving element is driven at a resonance point.   The rotary drive device according to any one of claims 1 to 8, wherein a plurality of the rotor and the displacement drive unit are arranged side by side in the axial direction of the rotary shaft. A frame surrounding the rotor,
The rotary drive device according to claim 1, wherein the drive element is attached to a surface side of the frame facing the rotor. An actuator using the rotational drive device according to any one of claims 1 to 10,
A robot apparatus comprising: an arm mechanism that is driven and controlled by the actuator. An actuator using the rotational drive device according to any one of claims 1 to 10,
An exposure apparatus comprising a stage mechanism that is driven and controlled by the actuator.

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