JP2021101593A - Piezoelectric drive device, piezoelectric motor, and robot - Google Patents

Abstract

To suppress deflection in a direction intersecting a direction of elliptical motion in a piezoelectric drive device and to suppress deflection in driving force transmitted from the piezoelectric drive device to a driven device.SOLUTION: A piezoelectric drive device comprises: a first vibrator having a substrate and a piezoelectric element laminated on the substrate along a first axis; a supporting part for supporting the first vibrator; and a chip arranged at a tip in a direction following a second axis orthogonal to the first axis in the first vibrator. A first deflection prevention part is arranged on a first face orthogonal to the first axis in the first vibrator, and at least a part of the first deflection prevention part is disposed between the support part and the chip in a direction following the second axis, and a dimension following the second axis of the first deflection prevention part is larger than a dimension following a third axis orthogonal to the first axis and the second axis of the first deflection prevention part on the first face.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to piezoelectric drives, piezoelectric motors, and robots.

Patent Document 1 discloses a piezoelectric drive device including a piezoelectric body having a piezoelectric element and a friction member that makes an elliptical motion due to vibration generated in the piezoelectric body.

Japanese Unexamined Patent Publication No. 2008-99549

In a piezoelectric drive device such as Patent Document 1, for example, a friction member is repeatedly brought into contact with and separated from a driven portion by an elliptical motion, thereby transmitting a driving force to the driven portion and causing the driven portion to move. Drive. However, when transmitting the driving force, the piezoelectric body may bend due to the force in the direction intersecting the direction of elliptical motion from the driven portion, and the driving force transmitted to the driven portion may vary. there were.

According to the first aspect of the present disclosure, a piezoelectric drive device is provided. This piezoelectric drive device includes a first vibrating body having a substrate, a piezoelectric element laminated on the substrate along the first axis, a support portion for supporting the first vibrating body, and the first vibrating body. , A tip provided at the tip in a direction along a second axis orthogonal to the first axis. A first bending prevention portion is provided on the first surface of the first vibrating body that intersects the first axis, and at least a part of the first bending prevention portion is in a direction along the second axis. The dimensions of the first anti-deflection portion along the second axis, which are provided between the support portion and the tip, are the same as that of the first axis of the first anti-deflection portion. It is larger than the dimension along the third axis orthogonal to the second axis.

According to the second aspect of the present disclosure, a piezoelectric motor is provided. The piezoelectric motor includes the piezoelectric drive device according to the first embodiment.

According to the third aspect of the present disclosure, a robot is provided. The robot includes an arm and a piezoelectric drive device according to the first embodiment.

It is explanatory drawing which shows the schematic structure of the piezoelectric motor. It is explanatory drawing which shows the schematic structure of the piezoelectric motor. It is a front view of the piezoelectric drive device. It is explanatory drawing which shows the structure of the piezoelectric drive device. It is a side view of the piezoelectric drive device. FIG. 3 is a sectional view taken along line VI-VI of the piezoelectric drive device of FIG. It is explanatory drawing which shows the operation of a piezoelectric drive device. It is a front view of the piezoelectric drive device of 2nd Embodiment. It is a side view of the piezoelectric drive device of 2nd Embodiment. It is explanatory drawing which shows the structure of the piezoelectric drive device of 3rd Embodiment. It is sectional drawing of the piezoelectric drive device of 4th Embodiment. It is a side view of the piezoelectric drive device of 5th Embodiment. It is sectional drawing of the piezoelectric drive device of 5th Embodiment. It is a perspective view which shows the schematic structure of the robot as 6th Embodiment. It is a front view of the piezoelectric drive device as another embodiment. It is a front view of the piezoelectric drive device as another embodiment.

A. First Embodiment:
1 and 2 are explanatory views showing a schematic configuration of the piezoelectric motor 10 according to the first embodiment. The piezoelectric motor 10 in the present embodiment includes a case 20 that constitutes the outer shape of the piezoelectric motor 10, a rotor 60 housed inside the case 20, and a bearing 50 that rotatably supports the rotor 60 with respect to the case 20. It is provided with a piezoelectric drive device 30 that applies a driving force to the rotor 60. In this embodiment, the piezoelectric motor 10 includes a plurality of piezoelectric drive devices 30. Each piezoelectric drive device 30 includes a piezoelectric element 32, and uses a modification of the piezoelectric element 32 to generate a driving force for rotating the rotor 60. The rotation of the rotor 60 is transmitted to the outside of the piezoelectric motor 10 via the rotation shaft portion 70. The piezoelectric motor 10 may be referred to as an ultrasonic motor. Further, the piezoelectric drive device 30 may be referred to as a piezoelectric actuator. Further, an element to which a driving force is applied from the piezoelectric driving device 30 may be referred to as a driven portion. In the present embodiment, the rotor 60 corresponds to the driven portion.

The case 20 is composed of a lower case 29 and a lid portion 23. The lower case 29 includes a bottom surface portion 21 and a side surface portion 22 erected from the outer peripheral edge of the bottom surface portion 21 toward the lid portion 23. An opening through which the rotating shaft portion 70 penetrates is provided in the center of the bottom surface portion 21. A protrusion 24 to which the outer ring of the bearing 50 is connected is provided at a position recessed from the opening on the bottom surface 21. Inside the outer peripheral edge of the bottom surface portion 21, a step portion 25 to which the piezoelectric drive device 30 is connected is provided. The lid portion 23 is connected to the upper end portion of the side surface portion 22 of the lower case 29 by a screw after the bearing 50, the rotor 60, and the piezoelectric drive device 30 are connected to the lower case 29. The lid portion 23 may be provided with a through hole through which wiring or the like passes.

The piezoelectric drive device 30 is fixed to the stepped portion 25 of the case 20 via the fixing member 36. The specific configuration and operation of the piezoelectric drive device 30 will be described later.

FIG. 2 shows the configuration of the piezoelectric motor 10 when viewed from the lid portion 23 toward the bottom surface portion 21. Specifically, FIG. 2 shows the piezoelectric drive device 30 and the rotor 60. The piezoelectric motor 10 in this embodiment is provided with four piezoelectric drive devices 30. The four piezoelectric drive devices 30 are arranged at equal intervals. The number of the piezoelectric drive devices 30 provided in the piezoelectric motor 10 is not limited to four, and may be three or less, or five or more. Further, the piezoelectric drive devices 30 do not have to be arranged at equal intervals.

The rotor 60 has an output unit 41 and a transmission unit 45 arranged on the outer periphery of the output unit 41 and connected to the output unit 41. The rotor 60 has a hollow output unit 41. The rotation of the rotor 60 is transmitted to the rotation shaft portion 70 via the output portion 41. In this embodiment, the rotor 60 rotates about the rotation axis RX. The direction from the lower case 29 toward the lid 23 along the rotation axis RX of the output unit 41 of the rotor 60 is called the axial direction AD, which is orthogonal to the rotation axis RX of the output unit 41 and goes outward from the rotation axis RX. The direction is called the radial RD. Further, the rotation direction of the rotor 60 is called a circumferential CD. These directions AD, RD, and CD in FIG. 1 and the directions AD, RD, and CD in other figures represent the same direction. The rotor 60 may have a solid output unit 41 instead of being hollow.

The transmission unit 45 receives a driving force from the chip 33 of the piezoelectric drive device 30 and transmits this driving force to the output unit 41. On the surface of the transmission unit 45 facing the lid portion 23 of the case 20, a contact surface 46 with which the chip 33 of the piezoelectric drive device 30 contacts is provided so as to face the axial direction AD. As shown in FIGS. 1 and 2, the piezoelectric drive device 30 is arranged in contact with the contacted surface 46 from the axial direction AD. Specifically, the chip 33 of the piezoelectric drive device 30 is in contact with the contacted surface 46 from the axial direction AD.

The bearing 50 is provided between the output portion 41 of the rotor 60 and the protrusion 24 of the case 20. The bearing 50 rotatably supports the rotor 60 with respect to the case 20. In the present embodiment, as the bearing 50, a roller bearing having an annular shape centered on the rotating shaft RX is used. The bearing 50 does not have to be a roller bearing, and may be, for example, a ball bearing.

FIG. 3 is a front view of the piezoelectric drive device 30 as viewed from the + Z direction. FIG. 4 is an explanatory diagram showing the configuration of the piezoelectric drive device 30. In FIG. 4, a part of the portion of the piezoelectric drive device 30 that cannot be seen from the outside is indicated by a broken line. Specifically, a plurality of piezoelectric elements 32 are indicated by broken lines. Further, in FIG. 3, a support portion 35 and a first bending prevention portion 51, which will be described later, are shown, but in FIG. 4, the first bending prevention portion 51 is omitted in order to facilitate understanding of the structure. ..

3 and 4 show arrows along the X, Y, and Z directions that are orthogonal to each other. The X, Y, and Z directions are directions along the X-axis, Y-axis, and Z-axis, which are three spatial axes orthogonal to each other, and one direction along the X-axis, Y-axis, and Z-axis, respectively. Includes both opposite directions. The X-axis and the Y-axis are axes along the horizontal plane, and the Z-axis is an axis along the vertical line. In other figures as well, arrows along the X, Y, and Z directions are appropriately represented. The X, Y, Z directions in FIGS. 3 and 4 and the X, Y, Z directions in the other figures represent the same direction. The Z-axis may be referred to as a first axis, the Y-axis may be referred to as a second axis, and the X-axis may be referred to as a third axis. The second axis is an axis orthogonal to the first axis. The third axis is an axis orthogonal to the first axis and the second axis. In the present specification, orthogonality includes a range of 90 ° ± 10 °.

As shown in FIGS. 3 and 4, the piezoelectric drive device 30 includes the first vibrating body 31 and the chip 33 described above, and a support portion 35 for supporting the first vibrating body 31. Further, in the present embodiment, the piezoelectric drive device 30 includes an arm portion 37 that supports the support portion 35. The first vibrating body 31 has a substrate 34 and a piezoelectric element 32 laminated on the substrate 34. The substrate 34 of the present embodiment has a substantially rectangular plate-like shape. The tip 33 is provided at the tip 39 of the first vibrating body 31 in the Y direction.

As shown in FIGS. 3 and 4, the arm portion 37 is arranged so as to face the first vibrating body 31 from the −X direction, the + X direction, and the −Y direction. A space sp for the first vibrating body 31 to vibrate is provided between the arm portion 37 and the first vibrating body 31. The arm portion 37 is fixed to the fixing member 36 shown in FIG. 1 via an elastic member such as a spring (not shown).

The support portion 35 is provided so as to extend from the arm portion 37 toward the first vibrating body 31 in the X direction. The support portion 35 supports the first vibrating body 31 from the X direction at the central portion of the first vibrating body 31 in the Y direction. In the present embodiment, the support portion 35 is provided integrally with the substrate 34 and the arm portion 37 of the first vibrating body 31. In the present embodiment, the substrate 34, the support portion 35, and the arm portion 37 are made of silicon. In another embodiment, for example, the first vibrating body 31, the support portion 35, and the arm portion 37 may be provided separately.

FIG. 5 is a side view of the piezoelectric drive device 30 as viewed from the + X direction. In FIG. 5, the support portion 35 and the arm portion 37 are omitted in order to facilitate understanding of the structure. As described above, the first vibrating body 31 is provided with the first bending prevention portion 51. Specifically, the first vibrating body 31 has a first surface 61, and the first surface 61 is provided with a first bending prevention portion 51 having a substantially rectangular parallelepiped shape. In the present embodiment, the first bending prevention portion 51 is fixed to the first surface 61 by an adhesive. That is, the first bending prevention portion 51 and the first vibrating body 31 are formed as separate bodies. Further, in the present embodiment, the first vibrating body 31 has a second surface 62, and the second surface 62 is provided with a second bending prevention portion 52 having a substantially rectangular parallelepiped shape. In the present embodiment, the second bending prevention portion 52 is adhered to the second surface 62 by an adhesive. Both the first surface 61 and the second surface 62 are surfaces orthogonal to the Z axis. The second surface 62 is the surface of the first vibrating body 31 opposite to the first surface 61.

In the present embodiment, both the first bending prevention portion 51 and the second bending prevention portion 52 are formed of silicon. In another embodiment, the first bending prevention portion 51 and the second bending prevention portion 52 may be made of other materials, for example, stainless steel or ceramics.

As shown in FIG. 3, at least a part of the first bending prevention portion 51 is provided between the support portion 35 and the chip 33 in the Y direction. In the present embodiment, all of the first bending prevention portions 51 are provided between the support portion 35 and the chip 33 in the Y direction. The second bending prevention unit 52 is the same as the first bending prevention unit 51.

As shown in FIG. 3, on the first surface 61, the dimension d2 in the Y direction of the first bending prevention portion 51 is larger than the d3 in the X direction of the first bending prevention portion 51. In the present embodiment, the dimension d1 in the Z direction of the first bending prevention portion 51 shown in FIG. 5 is smaller than the dimension d2 and smaller than the dimension d3. If the dimension d2 is larger than the dimension d3, the dimension d1 may be set to an arbitrary size. Further, the second bending prevention portion 52 also has the same dimensions as the first bending prevention portion 51. That is, on the second surface 62, d2 in the Y direction of the second bending prevention portion 52 is larger than the dimension d3 in the X direction of the second bending prevention portion 52.

As shown in FIG. 3, the first bending prevention portion 51 of the present embodiment is a line with respect to L1 passing through the midpoint of the line segment ls along the X direction constituting the first surface 61 when viewed from the Z direction. It is provided symmetrically. Specifically, the first bending prevention portion 51 has a substantially rectangular shape that is line-symmetric with respect to the straight line L1 along the Y axis when viewed from the + Z direction. In the present embodiment, the straight line L1 is a straight line that bisects the first surface 61 in the X direction. The second bending prevention unit 52 is the same as the first bending prevention unit 51.

FIG. 6 is a VI-VI cross-sectional view of the piezoelectric drive device 30 of FIG. As shown in FIG. 6, the piezoelectric element 32 is laminated on the substrate 34 along the Z axis. Specifically, on the substrate 34, as the piezoelectric element 32, the first piezoelectric element 32A, the second piezoelectric element 32B, the third piezoelectric element 32C, the fourth piezoelectric element 32D, and the fifth piezoelectric element 32E are provided. It is laminated. As shown in FIG. 4, the first piezoelectric element 32A is arranged at the center of the first vibrating body 31 in the X direction. The second piezoelectric element 32B and the third piezoelectric element 32C are arranged in the −X direction of the first piezoelectric element 32A. Note that FIG. 6 shows the fourth piezoelectric element 32D and the fifth piezoelectric element 32E located on the front side of the paper surface of FIG. 6, but the other piezoelectric elements 32 are not shown. The second piezoelectric element 32B is arranged between the support portion 35 and the chip 33 in the Y direction. The third piezoelectric element 32C is arranged in the −Y direction of the support portion 35. The fourth piezoelectric element 32D and the fifth piezoelectric element 32E are arranged in the + X direction of the first piezoelectric element 32A. The fourth piezoelectric element 32D is arranged between the support portion 35 and the chip 33 in the Y direction. The fifth piezoelectric element 32E is arranged in the + Y direction of the support portion 35.

The piezoelectric element 32 of this embodiment is made of lead zirconate titanate. The piezoelectric element 32 and the substrate 34 are adhered to each other by an insulating adhesive. In another embodiment, the piezoelectric element 32 may be formed of, for example, barium titanate or quartz instead of lead zirconate titanate. Further, for example, the piezoelectric element 32 may be laminated on the substrate 34 by being formed on the substrate 34 by a semiconductor process.

As shown in FIG. 6, the first vibrating body 31 of the present embodiment is composed of two substrates 34 and a piezoelectric element 32 laminated on each substrate 34. Specifically, the first vibrating body 31 is configured so that the piezoelectric elements 32 are brought into contact with each other and the piezoelectric elements 32 are sandwiched between the two substrates 34 from the outside. Therefore, in the present embodiment, the first surface 61 and the second surface 62 described above are each composed of surfaces on which the piezoelectric elements 32 of the two substrates 34 are not laminated.

As shown in FIGS. 3 to 6, in the present embodiment, the chip 33 has a shape protruding in the + Y direction. The tip 33 is adhered to the tip 39 of the first vibrating body 31 in the Y direction by an adhesive. The chip 33 is made of alumina. The chip 33 does not have to be made of alumina, in which case it is preferably made of a material having excellent wear resistance. For example, the material forming the chip 33 may be selected depending on the material forming the driven portion. Further, the tip 33 may be fixed to the tip 39 by other than adhesion. Further, the chip 33 may have another shape. For example, it may have a spherical shape, or may have a trapezoidal cross section on an XY plane.

FIG. 7 is an explanatory diagram showing the operation of the piezoelectric drive device 30. The phase of the AC current supplied to the second piezoelectric element 32B and the fifth piezoelectric element 32E and the phase of the AC current supplied to the third piezoelectric element 32C and the fourth piezoelectric element 32D are different by 180 degrees, and the first 1 By making the phase of the AC current supplied to the piezoelectric element 32A different from the phase of the AC current supplied to the second piezoelectric element 32B and the fifth piezoelectric element 32E by 90 degrees, the first vibrating body 31 is divided into two. The chip 33 can be made to move in an elliptical manner by being dimensionally deformed. By repeating the elliptical movement of the tip 33, the tip 33 and the contacted surface 46 of the transmission portion 45 repeatedly come into contact with each other. When the chip 33 comes into contact with the contact surface 46, the chip 33 transmits a driving force along the circumferential direction CD to the transmission unit 45. Therefore, while the tip 33 repeats the elliptical movement, the rotor 60 rotates about the rotation axis RX. The rotor 60 can be rotated in the opposite direction by reversing the alternating current supplied to the above-mentioned piezoelectric elements 32A to 32E by 180 degrees.

When the tip 33 that moves in an elliptical manner comes into contact with a driven portion such as the rotor 60, the tip 33 may receive a force in a direction intersecting the direction of the elliptical movement from the driven portion. Specifically, in FIG. 7, the tip 33 may receive a force in the Z direction from the rotor 60. When the tip 33 receives a force in the Z direction from the rotor 60, this force in the Z direction is also transmitted to the first vibrating body 31. At this time, the portion of the first vibrating body 31 between the support portion 35 and the tip 33 in the Y direction is more susceptible to the force in the Z direction than the other portion of the first vibrating body 31. Easy to bend in the Z direction. In the present embodiment, since the first vibrating body 31 is provided with the first bending preventing portion 51 and the second bending preventing portion 52, the bending of the first vibrating body 31 is suppressed.

When the driving force is transmitted to the driven portion, the piezoelectric drive device 30 generates heat due to vibration and friction. The first bending prevention unit 51 and the second bending prevention unit 52 promote heat transfer and heat dissipation from the piezoelectric drive device 30 to the outside. Specifically, when the first deflection prevention unit 51 and the second deflection prevention unit 52 are provided, the piezoelectric drive is performed as compared with the case where the first deflection prevention unit 51 and the second deflection prevention unit 52 are not provided. Since the area of the portion exposed to the outside of the device 30 is large, heat transfer and heat dissipation from the piezoelectric drive device 30 to the outside are promoted. This heat transfer and heat dissipation are further promoted, for example, by forming the first bending prevention portion 51 and the second bending prevention portion 52 with a material having a higher thermal conductivity than that of the first vibrating body 31.

According to the piezoelectric drive device 30 of the present embodiment described above, the first surface 61 of the first vibrating body 31 is provided with a first bending prevention portion 51 having a dimension d2 larger than the dimension d3 to prevent the first bending. At least a part of the portion 51 is provided between the support portion 35 and the chip 33 in the direction along the second axis. As a result, even when the tip 33 receives a force in the direction intersecting the direction of elliptical motion from the driven portion, the first bending prevention portion 51 suppresses the bending of the first vibrating body 31. Therefore, the variation in the driving force transmitted to the driven portion is suppressed.

Further, in the present embodiment, the first bending prevention unit 51 is formed on a straight line L1 that takes the midpoint of the line segment ls along the third axis constituting the first surface 61 when viewed from the direction along the first axis. On the other hand, it is provided line-symmetrically. Therefore, the bending of the first vibrating body 31 is suppressed more effectively by the first bending preventing portion 51.

Further, in the present embodiment, the first bending prevention unit 51 is configured as a separate body from the first vibrating body 31. Therefore, the bending of the first vibrating body 31 is suppressed by a simple configuration.

Further, in the present embodiment, the second surface 62 on the side opposite to the first surface 61 of the first vibrating body 31 is also provided with the second deflection preventing portion 52 having the dimension d2 larger than the dimension d3 to prevent the second deflection. At least a part of the portion 52 is provided between the support portion 35 and the chip 33 in the direction along the second axis. Therefore, in addition to the first bending prevention unit 51, the second bending prevention unit 52 also suppresses the bending of the first vibrating body 31.

B. Second embodiment:
FIG. 8 is a front view of the piezoelectric drive device 30b of the second embodiment as viewed from the + Z direction. FIG. 9 is a side view of the piezoelectric drive device 30b as viewed from the + X direction. In FIG. 9, in order to facilitate understanding of the structure, a part of the support portion 35, the arm portion 37, the first bending prevention portion 51b and the second bending prevention portion 52b, which will be described later, is omitted. The piezoelectric drive device 30b is provided in the piezoelectric motor 10 as in the first embodiment. In the piezoelectric drive device 30b, the configurations of the chip 33b and the first bending prevention portion 51b are different from those of the first embodiment. The piezoelectric drive device 30b has the same configuration as that of the first embodiment except for points not particularly described.

As shown in FIG. 9, the piezoelectric drive device 30b of the present embodiment has a first bending prevention unit 51b and a second bending prevention unit 52b, similarly to the first embodiment. As shown in FIG. 8, the first bending prevention portion 51b is provided so as to be point-symmetric with respect to the center point P1 of the first bending prevention portion 51b when viewed from the X direction. Specifically, the first bending prevention portion 51b has a cross-shaped shape that is point-symmetric with respect to the center point P1 when viewed from the X direction. In the present embodiment, the first bending prevention portion 51b has a shape that is line-symmetrical with respect to the straight line L1 and line-symmetrical with respect to the center point P1 when viewed from the + X direction. The second bending prevention unit 52b is the same as the first bending prevention unit 51b.

As shown in FIG. 9, unlike the first embodiment, the tip 33b of the present embodiment is adhered not only to the first vibrating body 31 but also to the first bending prevention portion 51b. Specifically, the tip of the first bending prevention portion 51b and the tip 39 of the first vibrating body 31 are at substantially equal positions in the Y direction, and the tip 33b has the tip 39 and the first bending prevention portion 51b in the Z direction. It is glued over the tip of the. The tip 33b is also adhered to the second bending prevention portion 52b.

As shown in FIG. 8, a part of the first bending prevention portion 51b of the present embodiment is provided continuously from the first vibrating body 31 to the support portion 35, unlike the first embodiment. Further, in the present embodiment, a part of the first bending prevention portion 51b is continuously provided from the support portion 35 to the arm portion 37. Specifically, the first bending prevention portion 51b has a portion formed over the first vibrating body 31, the support portion 35, and the arm portion 37 in the + Z direction of the piezoelectric drive device 30. The first bending prevention portion 51b is also fixed to the support portion 35 and the arm portion 37 by an adhesive. In the present embodiment, the second bending prevention portion 52b is also provided so as to be continuous from the first vibrating body 31 to the support portion 35 and continuous from the support portion 35 to the arm portion 37. Also in this embodiment, the dimension d2b in the Y direction is larger than the dimension d3b in the X direction on the first surface 61 and the second surface 62. Further, in FIG. 9, the portions provided on the support portion 35 and the arm portion 37 of the first bending prevention portion 51b and the portions provided on the support portion 35 and the arm portion 37 of the second bending prevention portion 52b. Is omitted together with the support portion 35 and the arm portion 37.

Even with the piezoelectric drive device 30b of the second embodiment described above, when the chip 33b receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the first deflection prevention portion 51b vibrates first. In order to suppress the bending of the body 31, the variation in the driving force transmitted to the driven portion is suppressed. In particular, in the present embodiment, the first deflection prevention portion 51b is provided so as to be point-symmetrical with respect to the center point P1 when viewed from the direction along the first axis, so that the first is more effective. The bending of the vibrating body 31 is suppressed.

Further, in the present embodiment, the tip 33b is adhered to the first vibrating body 31 and the first bending prevention portion 51b. Therefore, the adhesive strength of the chip 33b is improved.

Further, in the present embodiment, a part of the first bending prevention portion 51b is continuously provided from the first vibrating body 31 to the support portion 35. Therefore, the bending of the first vibrating body 31 is suppressed more effectively. In addition, the efficiency of heat transfer and heat dissipation from the piezoelectric drive device 30b to the outside is further enhanced.

C. Third Embodiment:
FIG. 10 is an explanatory diagram showing the configuration of the piezoelectric drive device 30c according to the third embodiment. FIG. 10 is a side view of the piezoelectric drive device 30c as viewed from the + X direction. The piezoelectric drive device 30c is also provided in the piezoelectric motor 10 as in the first embodiment. In the piezoelectric drive device 30c, the configuration of the first bending prevention unit 51c is different from that of the first embodiment. The piezoelectric drive device 30c has the same configuration as that of the first embodiment except for points not particularly described.

The piezoelectric drive device 30c of the present embodiment has a first bending prevention unit 51c and a second bending prevention unit 52c, as in the first embodiment. The end of the first bending prevention portion 51c of the present embodiment near the tip 33 is arranged between the tip tip 38, which is the tip of the tip 33, and the tip of the first vibrating body 31 in the direction along the second axis. Has been done. Specifically, the first bending prevention portion 51c projects in the + Y direction from the tip 39 of the first vibrating body 31. Further, the first bending prevention portion 51c does not protrude from the tip of the tip 33 in the + Y direction. The second bending prevention unit 52c is the same as the first bending prevention unit 51c.

Even with the piezoelectric drive device 30c of the third embodiment described above, when the chip 33 receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the first deflection prevention portion 51c vibrates first. In order to suppress the bending of the body 31, the variation in the driving force transmitted to the driven portion is suppressed. In particular, in the present embodiment, the end portion of the first bending prevention portion 51c near the tip 33 is arranged between the tip tip 38 and the tip of the first vibrating body 31 in the direction along the second axis. Therefore, the first bending prevention portion 51c effectively suppresses the bending of the first vibrating body 31 without hindering the contact between the tip 33 and the driven portion.

D. Fourth Embodiment:
FIG. 11 is a cross-sectional view of the piezoelectric drive device 30d according to the fourth embodiment. The piezoelectric drive device 30d is also provided in the piezoelectric motor 10 as in the first embodiment. In the piezoelectric drive device 30d, the configuration of the first bending prevention unit 51d is different from that of the first embodiment. The piezoelectric drive device 30d has the same configuration as that of the first embodiment except for points not particularly described.

In the present embodiment, unlike the first embodiment, the first bending prevention unit 51d is integrally formed with the first vibrating body 31. That is, the first vibrating body 31 is a part of the first vibrating body 31 and has a first bending prevention portion 51d as a portion protruding from the first surface 61 in the Z direction. Specifically, the first bending prevention portion 51d is configured as a portion of the substrate 34d that protrudes in the + Z direction. The second bending prevention portion 52d, like the first bending prevention portion 51d, is also a part of the first vibrating body 31 and is configured as a portion of the substrate 34d protruding in the −Z direction. Further, in the present embodiment, the first bending prevention unit 51d and the second bending prevention unit 52d are integrated with the first vibrating body 31, but are distinguished from the first vibrating body 31 for convenience. Specifically, the term "first vibrating body 31" does not include the first anti-deflection unit 51d and the second anti-deflection unit 52d. In FIG. 11, the boundary between the first vibrating body 31 and the first bending prevention portion 51d and the boundary between the first vibrating body 31 and the second bending preventing portion 52d are shown by broken lines.

Even with the piezoelectric drive device 30d of the fourth embodiment described above, when the chip 33 receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the first deflection prevention portion 51d vibrates first. In order to suppress the bending of the body 31, the variation in the driving force transmitted to the driven portion is suppressed. Further, in the present embodiment, the first bending prevention portion 51d is integrally formed with the first vibrating body 31. Therefore, the followability of the first bending prevention unit 51d to the first vibrating body 31 is improved.

E. Fifth embodiment:
FIG. 12 is a side view of the piezoelectric drive device 30e of the fifth embodiment as viewed from the + X direction. FIG. 13 is a cross-sectional view of the piezoelectric drive device 30e. The piezoelectric drive device 30e is also provided in the piezoelectric motor 10 as in the first embodiment. Unlike the first embodiment, the piezoelectric drive device 30e includes a second vibrating body 31B in addition to the first vibrating body 31. Further, the piezoelectric drive device 30e includes a first bending prevention unit 51, but does not include a second bending prevention unit 52. Further, unlike the first embodiment, the first vibrating body 31 does not have the second surface 62. The piezoelectric drive device 30e has the same configuration as that of the first embodiment except for points not particularly described.

Like the first vibrating body 31, the second vibrating body 31B has a substrate 34 and a piezoelectric element 32 laminated on the substrate 34 along the first axis. The second vibrating body 31B is laminated on the first vibrating body 31. Specifically, the second vibrating body 31B is laminated on the first vibrating body 31 with the first bending prevention portion 51 sandwiched between the second vibrating body 31B and the first vibrating body 31. That is, the first bending prevention portion 51 is provided between the first vibrating body 31 and the second vibrating body 31B. The support portion 35 supports the second vibrating body 31B in the same manner as supporting the first vibrating body 31 in FIG. The portion of the support portion 35 that supports the first vibrating body 31 and the portion that supports the second vibrating body 31B may be integrally formed or may be formed separately. .. The tip 33e is provided over the first vibrating body 31 and the second vibrating body 31B. That is, the tip 33e is provided at the second tip 39B in the direction along the second axis of the second vibrating body.

Also in the piezoelectric drive device 30e of the fourth embodiment described above, when the chip 33e receives a force in the direction intersecting the direction of elliptical motion from the driven portion, the first deflection prevention portion 51e is the first vibrating body. In order to suppress the bending of 31, the variation in the driving force transmitted to the driven portion is suppressed. In particular, in the present embodiment, the first bending prevention unit 51 also suppresses the bending of the second vibrating body 31B laminated on the first vibrating body 31.

F. Sixth Embodiment:
FIG. 14 is a perspective view showing a schematic configuration of the robot 100 as the sixth embodiment. The robot 100 in the present embodiment can perform operations such as supplying, removing, transporting, and assembling precision equipment and parts constituting the precision equipment. The robot 100 is a 6-axis robot, and is rotatably connected to a base 101 fixed to a floor or a ceiling, a first arm 102 rotatably connected to the base 101, and a first arm 102. With respect to the second arm 103, the third arm 104 rotatably connected to the second arm 103, the fourth arm 105 rotatably connected to the third arm 104, and the fourth arm 105. Controls the drive of the fifth arm 106 rotatably connected to the fifth arm 106, the sixth arm 107 rotatably connected to the fifth arm 106, and the respective arms 102, 103, 104, 105, 106, 107. A robot control unit 108 is provided. The sixth arm 107 is provided with a hand connection portion, and the hand connection portion is equipped with an end effector 109 according to the work to be executed by the robot 100. The piezoelectric drive device 30 described in the first embodiment is mounted on all or a part of each joint portion, and the driving force of the piezoelectric drive device 30 is transmitted to each arm 102, 103. , 104, 105, 106, 107 rotate. The drive of each piezoelectric drive device 30 mounted on the robot 100 is controlled by the robot control unit 108.

The robot control unit 108 is composed of one or more processors, a main storage device, and a computer including an input / output interface for inputting / outputting signals to / from the outside. In the present embodiment, the robot control unit 108 controls the operation of the robot 100 by executing a program or instruction read on the main storage device by the processor. The robot control unit 108 may be configured by a combination of a plurality of circuits instead of a computer.

According to the robot 100 of the present embodiment described above, since the piezoelectric drive device 30 described in the first embodiment is used for the joint portion, each arm 102, 103, 104, 105, 106, 107 is driven. The variation of the driving force to be made is suppressed. The robot 100 may include the piezoelectric drive devices 30b, 30c, 30d, 30e of the second to fifth embodiments in place of the piezoelectric drive device 30 or in addition to the piezoelectric drive device 30. ..

G. Other embodiments:
(G-1) In the above embodiment, the first vibrating body 31 is provided with a second bending prevention portion 52. On the other hand, the first vibrating body 31 may not be provided with the second bending prevention portion 52. In this case, the first vibrating body 31 does not have to have the second surface 62.

(G-2) In the above embodiment, the first bending prevention portion 51 is provided line-symmetrically with respect to the straight line L1. On the other hand, the first bending prevention portion 51 may not be provided line-symmetrically with respect to the straight line L1. For example, as shown in FIGS. 15 and 16, the first bending prevention unit 51 may have a shape that is not line-symmetrical with respect to the straight line L1 but point-symmetrical with respect to the center point P1. In FIG. 15, the first bending prevention portion 51f of the piezoelectric drive device 30f has a rectangular shape along one diagonal line of the first surface 61 on the first surface 61. In FIG. 16, the first bending prevention portion 51g of the piezoelectric drive device 30g has a bent shape that is point-symmetric with respect to the center point P1 on the first surface 61. Even in such a form, the bending of the first vibrating body 31 is suppressed more effectively. Further, the first bending prevention portion 51 does not have to have a shape that is not line-symmetrical with respect to the straight line L1 and is not point-symmetrical with respect to the center point P1. In this case, it is preferable that the first bending prevention portion 51 has a shape that does not hinder the vibration of the first vibrating body 31. The second bending prevention portion 52 may not be line-symmetrical with respect to the straight line L1 or may not be point-symmetrical with respect to the center point P1 as in the case of the first bending prevention portion 51. Further, the first bending prevention portion 51 and the second bending prevention portion 52 do not have to have the same shape.

(G-3) In the above embodiment, the first surface 61 is composed of surfaces on which the piezoelectric elements 32 of the substrate 34 are not laminated. On the other hand, the first surface 61 does not have to be composed of the substrate 34. For example, the first surface 61 may be composed of surfaces that are not in contact with the substrate 34 of the piezoelectric element 32. When the first vibrating body 31 has the second surface 62, the second surface 62 may not be composed of the substrate 34 in the same manner.

(G-4) In the above embodiment, the second vibrating body 31B is laminated on the first vibrating body 31 with the first bending prevention portion 51 sandwiched between the second vibrating body 31B and the first vibrating body 31. On the other hand, the first bending prevention portion 51 may not be provided between the second vibrating body 31B and the first vibrating body 31. For example, the second vibrating body 31B may be directly laminated on the first vibrating body 31, and the first bending prevention portion 51 may be provided on the surface of the first vibrating body 31 that is not in contact with the second vibrating body 31B. .. Similarly, the first bending prevention portion 51 may be provided on the surface of the second vibrating body 31B that is not in contact with the first vibrating body 31. Further, two bending prevention portions may be provided so as to sandwich the first vibrating body 31 and the second vibrating body 31B which are in direct contact with each other in the first direction. Further, for example, even in the case where a plurality of vibrating bodies of three or more are laminated to form the piezoelectric drive device, it is sufficient that the plurality of vibrating bodies are laminated in the same manner as described above.

H. Other forms:
The present disclosure is not limited to the above-described embodiment, and can be realized in various forms without departing from the spirit thereof. For example, the present disclosure can also be realized in the following forms. The technical features in each of the embodiments described below correspond to the technical features in the above embodiments in order to solve some or all of the problems of the present disclosure, or some or all of the effects of the present disclosure. It is possible to replace or combine as appropriate to achieve the above. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

(1) According to the first aspect of the present disclosure, a piezoelectric drive device is provided. This piezoelectric drive device includes a first vibrating body having a substrate, a piezoelectric element laminated on the substrate along the first axis, a support portion for supporting the first vibrating body, and the first vibrating body. , A tip provided at the tip in a direction along a second axis orthogonal to the first axis. A first bending prevention portion is provided on the first surface of the first vibrating body orthogonal to the first axis, and at least a part of the first bending prevention portion is in a direction along the second axis. The dimensions of the first anti-deflection portion along the second axis, which are provided between the support portion and the tip, are the same as that of the first axis of the first anti-deflection portion. It is larger than the dimension along the third axis orthogonal to the second axis.
According to such a form, even when the tip receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the bending of the vibrating body is suppressed by the first bending preventing portion. Therefore, the variation in the driving force transmitted from the piezoelectric driving device to the driven portion is suppressed.

(2) In the piezoelectric drive device of the above embodiment, the first bending prevention portion is a midpoint of a line segment along the third axis constituting the first surface when viewed from a direction along the first axis. It may be provided line-symmetrically with respect to a straight line passing through. According to such a form, the bending of the first vibrating body is suppressed more effectively by the first bending preventing portion.

(3) In the piezoelectric drive device of the above embodiment, the first bending prevention portion is provided so as to be point-symmetric with respect to the center point of the first bending prevention portion when viewed from the direction along the first axis. It may have been. According to such a form, the bending of the first vibrating body is suppressed more effectively by the first bending preventing portion.

(4) In the piezoelectric drive device of the above-described embodiment, the first bending prevention unit may be integrally formed with the first vibrating body. According to such a form, the followability of the first bending prevention portion to the first vibrating body is improved.

(5) In the piezoelectric drive device of the above-described embodiment, the first bending prevention unit may be formed separately from the first vibrating body. According to such a form, the bending of the first vibrating body is suppressed by a simple configuration.

(6) In the piezoelectric drive device of the above embodiment, the chip may be adhered to the first vibrating body and the first bending prevention portion. According to such a form, the adhesive strength of the chip is improved.

(7) In the piezoelectric drive device of the above embodiment, the end portion of the first bending prevention portion close to the chip is such that the tip of the chip and the tip of the first vibrating body are formed in a direction along the second axis. It may be arranged between them. According to such a form, the first bending prevention portion can effectively suppress the bending of the first vibrating body without hindering the contact between the tip and the driven portion.

(8) In the piezoelectric drive device of the above embodiment, a part of the first bending prevention portion may be continuously provided from the first vibrating body to the support portion. According to such a form, the bending of the first vibrating body is suppressed more effectively. In addition, the efficiency of heat transfer and heat dissipation from the piezoelectric drive device to the outside is further enhanced.

(9) In the piezoelectric drive device of the above embodiment, the first vibrating body has a second surface opposite to the first surface, and the second surface is provided with a second bending prevention portion. At least a part of the second bending prevention portion is provided between the support portion and the tip in the direction along the second axis, and the dimension of the second bending prevention portion along the second axis is , The dimension of the second bending prevention portion may be larger than the dimension along the first axis and the third axis orthogonal to the second axis. According to such a form, the bending of the first vibrating body is suppressed by the second bending preventing portion in addition to the first bending preventing portion.

(10) The piezoelectric drive device of the above embodiment includes a second vibrating body having a substrate and a piezoelectric element laminated on the substrate along the first axis, and the second vibrating body is the first vibrating body. The support portion supports the second vibrating body, the tip is provided at the tip of the second vibrating body in the direction along the second axis, and the first bending prevention portion is provided. It may be provided between the first vibrating body and the second vibrating body. According to such a form, the bending of the second vibrating body laminated on the first vibrating body is also suppressed by the first bending preventing portion.

(11) According to the second aspect of the present disclosure, a piezoelectric motor is provided. The piezoelectric motor includes the piezoelectric drive device according to the first embodiment.
According to such a form, even when the tip receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the bending of the first vibrating body is suppressed by the first bending preventing portion. .. Therefore, the variation in the driving force transmitted from the piezoelectric driving device to the driven portion is suppressed.

(12) According to the third aspect of the present disclosure, a robot is provided. The robot includes an arm and a piezoelectric drive device according to the first embodiment.
According to such a form, even when the tip receives a force in a direction intersecting the direction of elliptical motion from the driven portion, the bending of the first vibrating body is suppressed by the first bending preventing portion. .. Therefore, the variation in the driving force transmitted from the piezoelectric driving device to the driven portion is suppressed.

The present disclosure is not limited to the above-mentioned piezoelectric drive device, piezoelectric motor and robot, and can be realized in various aspects. For example, other than the above, it can be realized as various devices using a piezoelectric drive device.

10 ... Piezoelectric motor, 20 ... Case, 21 ... Bottom part, 22 ... Side part, 23 ... Lid part, 24 ... Projection part, 29 ... Lower case, 30, 30b, 30c, 30d, 30e, 30f, 30g ... Piezoelectric drive Device, 31 ... 1st vibrating body, 31B ... 2nd vibrating body, 32 ... Piezoelectric element, 32A ... 1st piezoelectric element, 32B ... 2nd piezoelectric element, 32C ... 3rd piezoelectric element, 32D ... 4th piezoelectric element, 32E ... Fifth piezoelectric element, 33, 33b, 33e ... Chip, 34 ... Substrate, 35 ... Support, 36 ... Fixing member, 37 ... Arm, 38 ... Chip tip, 39 ... Tip, 39B ... Second tip, 41 ... Output unit, 45 ... Transmission unit, 46 ... Contacted surface, 50 ... Bearing, 51, 51b, 51c, 51d, 51f, 51g ... First deflection prevention unit, 52, 52b, 52c ... Second deflection prevention unit, 60 ... Rotor, 61 ... 1st surface, 62 ... 2nd surface, 70 ... Rotating shaft, 100 ... Robot, 101 ... Base, 102 ... 1st arm, 103 ... 2nd arm, 104 ... 3rd arm, 105 ... 4th Arm, 106 ... 5th arm, 107 ... 6th arm, 108 ... Robot control unit, 109 ... End effector

Claims (12)

A first vibrating body having a substrate and a piezoelectric element laminated on the substrate along the first axis.
A support portion that supports the first vibrating body and
A tip provided at the tip of the first vibrating body in a direction along a second axis orthogonal to the first axis is provided.
A first bending prevention portion is provided on the first surface of the first vibrating body, which is orthogonal to the first axis.
At least a part of the first bending prevention portion is provided between the support portion and the chip in the direction along the second axis.
On the first surface, the dimension of the first anti-deflection portion along the second axis is the dimension of the first anti-deflection portion along the first axis and the third axis orthogonal to the second axis. Larger, piezoelectric drive. The piezoelectric drive device according to claim 1.
The first bending prevention portion is provided line-symmetrically with respect to a straight line passing through the midpoint of a line segment along the third axis constituting the first surface when viewed from a direction along the first axis. Piezoelectric drive device. The piezoelectric drive device according to claim 1 or 2.
The first bending prevention portion is a piezoelectric drive device provided so as to be point-symmetrical with respect to the center point of the first bending prevention portion when viewed from a direction along the first axis. The piezoelectric drive device according to any one of claims 1 to 3.
The first bending prevention unit is a piezoelectric drive device integrally configured with the first vibrating body. The piezoelectric drive device according to any one of claims 1 to 4.
The first bending prevention unit is a piezoelectric drive device that is formed separately from the first vibrating body. The piezoelectric drive device according to any one of claims 1 to 5.
A piezoelectric drive device in which the tip is adhered to the first vibrating body and the first bending prevention portion. The piezoelectric drive device according to any one of claims 1 to 6.
A piezoelectric drive device in which an end portion of the first bending prevention portion close to the chip is arranged between the tip of the chip and the tip of the first vibrating body in a direction along the second axis. The piezoelectric drive device according to any one of claims 1 to 7.
A part of the first bending prevention portion is a piezoelectric drive device that is continuously provided from the first vibrating body to the support portion. The piezoelectric drive device according to any one of claims 1 to 8.
The first vibrating body has a second surface opposite to the first surface.
A second bending prevention portion is provided on the second surface.
At least a part of the second bending prevention portion is provided between the support portion and the chip in the direction along the second axis.
A piezoelectric drive device on the second surface, wherein the dimension of the second anti-deflection portion along the second axis is larger than the dimension of the second anti-deflection portion along the third axis. The piezoelectric drive device according to any one of claims 1 to 9.
A second vibrating body having a substrate and a piezoelectric element laminated on the substrate along the first axis is provided.
The second vibrating body is laminated on the first vibrating body.
The support portion supports the second vibrating body and supports the second vibrating body.
The tip is provided at the tip of the second vibrating body in a direction along the second axis.
The first bending prevention unit is a piezoelectric drive device provided between the first vibrating body and the second vibrating body. A piezoelectric motor comprising the piezoelectric drive device according to any one of claims 1 to 10. With the arm
A robot comprising the piezoelectric driving device according to any one of claims 1 to 10, which drives the arm.

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