JP7301705B2 - Rotary Oscillatory Wave Drives, Optics, and Electronics - Google Patents

Description

The present invention relates to an ultrasonic motor having a vibrating body and a contact body and driving the contact body.

In general, an ultrasonic motor has a vibrating body in which driving vibration is generated and a contact body that press-contacts the vibrating body, and the vibrating body and the contact body are relatively moved by the driving vibration. By giving appropriate elasticity to the contact portion between the vibrating body and the contact body, it is possible to suppress the generation of abnormal noise and to improve the sliding efficiency because the force is properly transmitted. As the shape of the contact portion, for example, shapes such as those disclosed in Patent Documents 1 and 2 have been proposed.

In Japanese Unexamined Patent Application Publication No. 2002-100001, the contact portion is made of a nitrided stainless steel plate, and a part of the contact portion is removed by etching to form a spring portion, thereby imparting elasticity. A contact body is formed by joining this stainless steel plate to another member. However, the etching process has a problem that the time required for processing is long and the processing cost is high.

In Japanese Patent Laid-Open No. 2002-200013, in the contact portion that is responsible for contact between the vibrating body and the contact body, the contact portion on the contact body side is subjected to bending by press work or the like, and a ring formed so as to have a C-shaped cross section is formed as a main body of a separate member. Examples are described in which the parts are joined by means of adhesives, metal brazing, welding, or the like. By configuring in this way, it is possible to adopt bending work that requires less man-hour than cutting work, so that it is possible to significantly reduce the processing cost. However, the flatness of the member obtained by bending a part of the thin plate is deteriorated due to the influence of warping and the like, and the contact state between the ring and the main body changes depending on the position in the circumferential direction. As a result, the rigidity of the contact portion varies depending on the position in the circumferential direction, and the contact state between the contact body and the vibrating body becomes uneven, generating abnormal noise and reducing the sliding efficiency of the contact portion, resulting in poor performance. There was a problem of lowering

JP 2006-211755 JP 2010-263769

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rotary vibration wave driving device that suppresses abnormal noise and has stable performance.

A rotary vibration wave drive device of the present invention comprises a vibrating body having an annular elastic body and an electro-mechanical energy conversion element,
an annular contact body in contact with the vibrating body, wherein the contact body includes a main body, a planar section joined to the main body via a bonding layer, and the vibrating body provided at one end of the planar section. and a portion where the thickness of the bonding layer is thick from the one end to the other end.

According to the present invention, non-uniformity in the static rigidity of the contact portion is alleviated, a stable contact state between the contact body and the vibrating body is realized, and a rotary vibration wave drive device that suppresses the generation of abnormal noise is provided. do.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows sectional drawing of the rotary vibration wave drive device in Example 1 of this invention. It is a figure which shows the structure of the contact part of the rotary vibration wave drive device in Example 1 of this invention. It is a figure explaining the effect of the rotary vibration wave drive device in Example 1 of this invention. It is a figure which shows other structures of the contact part of the rotary vibration wave drive device in Example 1 of this invention. FIG. 8 is a diagram showing the structure of the contact portion of the rotary vibration wave drive device according to Embodiment 2 of the present invention; It is a figure which shows other structures of the contact part of the rotary vibration wave drive device in Example 2 of this invention. It is a figure which shows other structures of the contact part of the rotary vibration wave drive device in Example 2 of this invention.

A rotary vibration wave drive device of the present invention comprises a vibrating body having an annular elastic body and an electro-mechanical energy conversion element,
a ring-shaped contact body in contact with the vibrating body, the contact body comprising a main body, a planar section joined to the main body via a bonding layer, and a contact with the vibrating body provided at one end of the planar section. have an edge. A portion where the thickness of the bonding layer is thick is provided from the one end toward the other end. A detailed description will be given below with reference to the drawings.

Embodiment 1 FIG. 1 shows a cross-sectional view of a rotary vibration wave driving device according to Embodiment 1 of the present invention. A vibrating body 1 having an annular elastic body and an electro-mechanical energy conversion element 10 is adapted to excite traveling wave vibration by applying alternating current through electrodes (not shown). The electro-mechanical energy conversion element can be composed of a piezoelectric element or an electrostrictive element. When a piezoelectric element is used, PZT or a lead-free piezoelectric material such as barium titanate is used as the piezoelectric material for the piezoelectric element. you can

An annular contact member 2 is in contact with the vibrating member 1, and the vibrating member 1 and the contact member 2 are in contact with each other while being pressed by an urging member 3. As shown in FIG. The contact member 2 and the vibrating member 1 are configured to be relatively movable in the circumferential direction due to the traveling wave vibration that is excited in the vibrating member 1 and progresses in the circumferential direction. A pressure transmitting member 11 and a pressure receiving member 12 are interposed between the biasing member 3 and the electro-mechanical energy conversion element 10, so that the biasing force of the biasing member 3 is evenly applied. ing. As the biasing member 3, in this embodiment, a plurality of annular leaf springs are used, but a wave washer, a plurality of coil springs, or the like may be used. In addition to felt, rubber can also be used as the pressure transmitting member 11 .

The vibrating body 1 is supported by an anti-rotation member (not shown) so as not to rotate relative to the base member 4 . A weight 5 is attached via a rubber member 6 to a portion of the contact member 2 opposite to the portion in contact with the vibrating member 1, which is depicted in the upper part of FIG. As the material of the rubber member 6, silicon rubber or the like can be used in addition to butyl rubber. Also, in this embodiment, the rubber member 6 is used as a means for joining the contact member 2 and the weight 5, but the contact member 2 and the weight 5 may be fixed by means of adhesion, screw fastening, or the like without using rubber. The weight 5 is supported by the shaft 8 so as to rotate integrally therewith. The shaft 8 is relatively rotatably supported by the base member 4 via two rotary bearings 7a and 7b. In order to prevent the rotation bearing 7b from coming off from the shaft 8, it is positioned so that displacement in the vertical direction of the plane of FIG. Therefore, the vibrating body 1 and the contacting body 2 are adapted to rotate relative to each other about a predetermined rotation axis. Further, instead of the rotary bearing 7, a sliding bearing, a thrust bearing, or another type of bearing may be used.

The configuration of the contact member 2 will be described with reference to FIG. FIG. 2 is an enlarged view of a portion where the vibrating body 1 and the contact body 2 are in contact with each other from the sectional view shown in FIG. In FIG. 2, the contact member 2 includes a flat portion 201 and a body portion 202, which are contact portions, and a bonding layer 203 that bonds the two. The flat portion 201 has a contact end that is in contact with the vibrating body 1 forming one end of the flat portion 201 .

As the bonding layer 203, an adhesive such as a two-liquid epoxy adhesive or an anaerobic adhesive, a UV curable adhesive, an adhesive resin, or the like can be used. The joining layer should just contain these materials. That is, it may be a material that is both anaerobic and UV curable, or a mixture of anaerobic and UV curable adhesives.
The plane portion 201 is made of SUS material and is produced by punching out from a base material by press working. The body portion 202 is formed by cutting a metal material such as brass having excellent machinability.

Since the contact member 2 is in frictional contact with the vibrating member 1, a material with excellent wear resistance is required to achieve high durability. It is desirable to consist of However, materials with excellent wear resistance are poor in machinability, and if the same shape as the contact body 2 of the present embodiment is entirely formed by cutting, the machining cost will increase significantly. However, by joining the flat portion 201 formed by press working and the body portion 202 formed by cutting a material having excellent free-cutting properties as in this embodiment, the processing cost can be greatly reduced.

However, when the flat portion 201 is formed by pressing, there is a problem that warpage occurs during pressing or during quenching/annealing for increasing the surface hardness of the flat portion 201 . This problem will be described below.

In the vibration wave actuator, it is desirable that the contact portion that makes contact between the vibrating body 1 and the contact body 2 has some degree of elasticity. Due to the elasticity, it is possible to suppress the generation of unnecessary vibrations at the contact portion and to suppress the generation of abnormal noise. At this time, if there is a difference in static rigidity in the circumferential direction at the contact portion, the deformed shape of the contact portion will differ from place to place. As a result, a difference occurs in the contact state, causing problems such as the traveling wave vibration generated by the vibrating body not being transmitted uniformly, generating abnormal noise, and lowering the driving efficiency. In particular, when a contact member made up of a plurality of members such as the elastic portion and the main ring portion of this embodiment is used, unevenness in the thickness of the bonding layer occurs if the elasticity is warped or the flatness is poor. put away. As a result, the distribution of the static stiffness is greatly influenced by the stiffness of the bonding layer, and variations occur in the static stiffness distribution.

In order to solve the above problems, as shown in FIG. do. Furthermore, the flat portion 201 and the main body portion 202 are joined via the joining layer 203 in a state in which the inner edge A of the main body portion 202 and the flat portion 201 are in contact with each other. For this reason, the bonding layer 203 is inclined from the inner peripheral side to the outer peripheral side, whereby the thickness on the outer peripheral side is larger than that on the inner peripheral side. In this embodiment, the magnitude of the warp is assumed to be 0.1 mm to 0.2 mm, and if the warp is expressed as an inclination angle, it is assumed to be in the range of 1° to 4° with respect to the horizontal direction. The range is not limited.

Here, the effects of the configuration as described above will be described. FIG. 3(a) is a diagram showing the concept of when force F is applied to the vicinity of the contact portion of the contact body 2 in this embodiment. In FIG. 3A, when a force F is applied near the contact portion (contact end) between the plane portion 201 and the vibrating body (not shown), the plane portion 201 and the main body portion 202 move toward the inner peripheral side of the main body portion 202. Since they are in contact with each other at the edge A, a force F acts to displace the plane portion 201 with the edge A as a fulcrum. Therefore, when the flat portion 201 receives the force F and deforms, the range from the edge A to the inner peripheral side edge of the flat portion 201 acts as a spring. In contrast, as shown in FIG. 3B, consider the case where the plane portion 201 is warped in the opposite direction. In FIG. 3B, when a force F is applied near the contact portion between the flat portion 201 and the vibrating body (not shown), the flat portion 201 and the body portion 202 are in contact with each other at the edge A on the outer peripheral side of the flat portion 201. Similarly, a force F acts with the edge A as a fulcrum so as to displace the flat portion 201 and the bonding layer 203 . That is, in the vicinity of the contact portion (contact end), the combined static rigidity of the flat portion 201 and the static rigidity of the bonding layer 203 becomes an elastic portion, which acts as a spring. That is, the thickness of the bonding layer 203 has an effect. The thickness of the bonding layer 203 is determined by the warp of the flat portion 201, but the warp of the flat portion 201 formed by pressing is not uniform in the circumferential direction. Therefore, in the configuration of FIG. 3B, the static rigidity of the contact body 2 at the contact portion varies in the circumferential direction.

As described above, by configuring as shown in FIG. 3A, the flat portion 201 can be made to act predominantly as the elasticity of the contact body 2, and stable without being affected by the bonding layer. It becomes possible to provide a rotary drive device that exhibits performance. To give an example in adopting the configuration of FIG. 3A, attention is focused on three points equidistantly spaced in the circumferential direction of the annular contact body. At that time, the thickness of the bonding layer increases in the direction from one end to the other end with reference to the contact end with the vibrating body provided at one end of the flat portion formed in a shape with the top portion of a cone cut off. If the part is provided, the effect will be exhibited.

As another configuration of the present embodiment, as shown in FIG. 4, the body portion 205 may be provided with a portion having a thin wall thickness in a direction away from the center in the radial direction to achieve the same effect. By changing the thickness of the main body portion 205 in the radial direction, it is possible to bond the flat portion 204 without worrying about the direction of the warp, regardless of what kind of warpage occurs in the plane portion 204. Therefore, there is a difference in rigidity depending on the position in the circumferential direction. can be reduced.

FIG. 5 is a diagram showing the configuration around the contact portion in the second embodiment of the present embodiment. Since the basic configuration of the whole is the same as that of the first embodiment, the explanation is omitted and only the parts different from the first embodiment are explained.

In this embodiment, the shapes of the vibrating body 13 and contact body 22 are different from those of the first embodiment. The vibrating body 13, which has an annular elastic body and an electro-mechanical energy conversion element, has a cross section in the radial direction of the annular elastic body that approximates a trapezoid, and a planar contact surface. Therefore, the processing cost can be reduced more than the first embodiment. In addition, the cross-sectional shape is not limited to a trapezoid, and may be a quadrangle. The contact member 22 is composed of a main body portion 202 and a flat portion 207, and a raised portion 208 is integrally provided at the inner diameter side end portion of the flat portion 207. As shown in FIG. When forming the raised portion 208 on the plane portion 207, press working is preferable from the viewpoint of cost, but it may be formed by means such as cutting or etching. An end portion of the raised portion 208 is pressed against the vibrating body 13, and the vibrating body 13 and the contact body 22 are configured to move relative to each other.

Further, the planar portion 207 has a shape of a cone whose apex protrudes from the center of the annular elastic body toward the center of the annular contact body, with the apex notched, and the bonding layer 209 extends from the inner peripheral side. Also, the thickness on the outer peripheral side is increased.

With the configuration as described above, when the biasing force F is applied from the vibrating body 13 to the contact body 22 , the entire plane portion 207 is pressed against the main body portion 202 . At this time, the flat portion 207 and the rising portion 208 protrude from the main body portion 202 in the direction of the central axis of the vibrating body 1 . Therefore, a portion of the planar portion 207 that is not adhered to the body portion 202 acts as an elastic spring, and the portion of the planar portion 207 is elastically deformed with the edge A on the inner peripheral side of the body portion 202 as a fulcrum.

As in Example 1, the difference in thickness of the bonding layer is assumed to be 0.1 mm to 0.2 mm, but as long as sufficient elasticity is ensured, the difference may be any difference. As described above, it is important that the flat portion has a portion that contacts the main body portion on the one end side.

Further, as shown in FIG. 6, a flat portion 210 and a raised portion 212 integrally formed with the flat portion 210 are formed on the main body portion 205 having a thin portion extending radially from the center. May be joined. Even in this case, since the thickness of the bonding layer 211 is larger on the outer peripheral side, it is possible to provide an annular vibration wave driving device having the same effect. By changing the thickness of the main body portion 205 in the radial direction, it is possible to join the plane portion 210 without worrying about the direction of warping, regardless of what kind of warpage occurs in the plane portion 210, and the difference in rigidity depending on the position in the circumferential direction. can be reduced.

Furthermore, as shown in FIG. 7, a raised portion 214 may be provided at one end of the flat portion 213 and a second flat portion 216 may be provided at the other end. Even in this case, since the thickness of the bonding layer 211 is larger on the outer peripheral side, it is possible to provide an annular vibration wave driving device having the same effect. Furthermore, considering the specific configuration when forming the plane portion 213, which is the contact portion of the contact member 24 with the vibrating member 13, by bending using a press or the like, there are the following advantages. That is, even if the warp near the rising portion 214 is directed toward the vibrator 13 , the direction can be corrected by bending between the second flat portion 216 and the flat portion 213 .

With the configuration as described above, the width of the contact surface is narrower than that of the first embodiment, so that it is less susceptible to the flatness of the contact surface and the like, and more stable performance can be exhibited.

Further, the contact end may be configured by a curved portion curved in a direction from the center of the annular elastic body toward the center of the annular contact body, or a plurality of curved portions may be provided.

Further, as an application example of the present invention, an optical element, an imaging element, and the rotary vibration wave driving device described above are provided, and the relative position between the optical element and the imaging device is determined by driving the rotary vibration wave driving device. An optical instrument configured to change . Further, not limited to optical equipment, it has a rotary vibration wave driving device and a movable part connected to the rotary vibration wave driving device, and the movable part is driven by the rotary vibration wave driving device. An electronic device configured to be displaced may be configured.

INDUSTRIAL APPLICABILITY The present invention is applicable to vibration type driving devices such as ultrasonic motors.

REFERENCE SIGNS LIST 1 vibrating body 2 contacting body 3 biasing member 4 base member 5 weight 6 rubber member 7 rotary bearing 8 shaft 9 disengagement prevention member 10 electrical-mechanical energy conversion element 11 pressure transmitting member 12 pressure receiving member 13 vibrating body 201 plane portion 202 body part 203 joining layer 204 plane part 205 body part 207 plane part 208 rising part 209 joining layer 210 plane part 211 joining layer 212 rising part 213 plane part 214 rising part 215 joining layer 216 second plane part

Claims (13)

a vibrating body having an annular elastic body and an electro-mechanical energy conversion element;
an annular contact body in contact with the vibrating body,
The contact member has a body portion, a flat portion bonded to the body portion via a bonding layer, and a contact end with the vibrating body provided at one end of the flat portion,
A rotary vibration wave driving device in which a portion where the thickness of the bonding layer is thick is provided in a direction from the one end to the other end. 2. A rotary vibration wave driving device according to claim 1, wherein said contact end is a raised portion provided integrally with an end of said flat portion. 3. The rotary vibration wave driving device according to claim 1, wherein the joining layer is inclined from the one end to the other end. The rotary vibration wave driving device according to any one of claims 1 to 3, wherein the planar portion has a portion contacting the main body portion at the one end side. 5. The rotary vibration wave driving device according to claim 1, wherein the direction from the one end to the other end is the radial direction of the annular contact body. 6. The contact end according to claim 1, wherein the contact end protrudes from the body portion toward the center of the annular contact body in a radial direction of the annular contact body. A rotary oscillatory wave drive device as described. 7. The planar portion has a shape of a cone whose apex is notched and protrudes from the center of the annular elastic body toward the center of the annular contact body. 2. The rotary vibration wave driving device according to 1. 8. The contact end according to any one of claims 1 to 7, wherein the contact end is formed by a bent portion that warps in a direction from the center of the annular elastic body toward the center of the annular contact body. A rotary oscillatory wave drive device as described. 9. The rotary vibration wave driving device according to claim 8, comprising a plurality of said bent portions. 10. The rotary vibration wave driving device according to claim 1, wherein the planar portion is made of SUS material. The rotary vibration wave according to any one of claims 1 to 10, wherein the bonding layer contains an epoxy adhesive, an anaerobic adhesive, a UV curable adhesive, or a resin. drive. 12. The body portion according to any one of claims 1 to 11, wherein the main body portion has a thin portion in a direction away from the center of the annular contact body in a radial direction of the annular contact body. 1. A rotary vibration wave driving device according to claim 1. an optical element;
an imaging device;
Having the rotary vibration wave driving device according to any one of claims 1 to 12,
An optical apparatus configured such that a relative position between the optical element and the imaging element is changed by driving the rotary vibration wave driving device.

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