JPH1141956A - Stator and vibration plate of ultrasonic motor, and ultrasonic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain required speed characteristics without requiring a complicated control of AC voltage by sloping at least one of two side surfaces in a direction of a traveling a moving body of a stator contact portion. SOLUTION: Both the side surfaces 4a in the peripheral direction of each projection 4 are sloped to one direction (counter-clockwise) and thus a vibration component of the vibration of a traveling wave in one direction at the side where the each projection 4 is sloped becomes larger. Thus, a rotor 5 rotates at the sloped side of the projection 4, that is, when it rotates counter-clockwise, the ultrasonic motor will have a high speed rotation. On the contrary, if the rotor 5 rotates in a direction opposite to the sloped side, that is in the clockwise, its vibration component becomes smaller compared to the rotation in one direction, and the ultrasonic motor will have a low speed rotation. Thus, even though the frequency variable control is not performed, the rotor 5 of the ultrasonic motor can be rotated at a high speed in one direction and rotated at a low speed in the reverse direction only by controlling the phase of a high frequency AC voltage without performing a frequency variable control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stator of an ultrasonic motor, and more particularly, to a structure of a diaphragm constituting the stator.

[0002]

2. Description of the Related Art A conventional ultrasonic motor stator is disclosed, for example, in Japanese Patent Application Laid-Open No. 8-298793. The stator includes a vibrating plate (vibrating body), a base ring (ring-shaped metal member) bonded to a lower surface of an outer peripheral portion of the vibrating plate, and a piezoelectric element (electric-mechanical energy conversion element) bonded to a lower surface of the base ring. It has. A plurality of projections are formed on the diaphragm as a stator contact portion which is bent in the radial direction and extended in the vertical direction by press working.

In such a stator, a plurality of electrode plates are bonded in a circumferential direction on a lower surface of the piezoelectric element. The plurality of electrode plates are polarized such that adjacent electrode plates have opposite polarities. When a high-frequency AC voltage is applied to the electrode plate, the piezoelectric element is driven based on the phase difference, frequency, and voltage value of the AC voltage, and a traveling vibration wave is generated at a stator contact portion of the diaphragm.

[0004]

By the way, depending on the place and application where the motor is used, for example, the motor is fast in the forward direction,
Various rotational speed characteristics are required, such as slow rotation in the reverse direction. However, in the above-described stator, since the speed of the traveling vibration wave is controlled based on the frequency of the applied AC voltage, in order to obtain a desired rotation speed characteristic, a phase difference for controlling the direction of rotation is obtained. In addition to the control, it is necessary to variably control the frequency of the AC voltage. Therefore,
The control device for controlling the AC voltage causes an increase in the cost of the entire ultrasonic motor device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an ultrasonic motor which can obtain a desired speed characteristic without complicated control of an AC voltage. It is to provide a stator, a diaphragm and an ultrasonic motor.

[0006]

According to a first aspect of the present invention, there is provided a diaphragm having a plurality of standing stator contact portions which come into contact with a movable body, and a stator provided below the diaphragm, A stator of an ultrasonic motor including a piezoelectric element that generates a vibration wave at a contact portion, wherein the stator contact portion has at least one of two side surfaces inclined in a direction in which the movable body is moved. The gist is that.

According to a second aspect of the present invention, in the ultrasonic motor stator according to the first aspect, the movable body, the vibration plate, and the piezoelectric element are formed in an annular shape.

[0008] The invention according to claim 3 is the invention according to claim 1 or 2.
Wherein the diaphragm having the stator contact portion is formed by press working.

The invention described in claim 4 is the first to third aspects of the present invention.
In the stator of the ultrasonic motor according to any one of the above, the vibration wave is a traveling wave. According to a fifth aspect of the present invention, in the ultrasonic motor stator according to any one of the first to third aspects, the vibration wave is a standing wave.

According to a sixth aspect of the present invention, there is provided a plurality of standing stator contact portions which come into contact with the movable body, and the stator contact portions are at least one of both side surfaces in the direction in which the movable body is moved. The gist is a diaphragm whose side surface is inclined.

[0011] The invention according to claim 7 is the invention according to claims 1 to 5.
An ultrasonic motor provided with the stator according to any one of the above aspects. According to the first aspect of the present invention, at least one of the two side surfaces of the stator contact portion of the diaphragm in the moving direction of the movable body is inclined. Therefore, when the piezoelectric element is driven, the vibration component of the vibration wave generated in the stator contact portion can be increased in one direction and reduced in the opposite direction due to the inclination of the side surface of the stator contact portion. As a result, the ultrasonic motor using this stator can control the speed characteristics such that the speed becomes high when the movable body is driven in one direction and becomes low when the movable body is driven in the opposite direction, without changing the frequency. Can do it.

According to the second aspect of the present invention, the movable body, the diaphragm and the piezoelectric element are formed in an annular shape. Therefore, the movable body is rotationally driven on the stator contact portion of the diaphragm.

According to the third aspect of the present invention, the diaphragm having the stator contact portion is formed by press working. Therefore, the production time can be reduced and the cost can be reduced as compared with the processing using cutting or grinding.

According to the present invention, the vibration wave of the stator is a traveling wave, and the stator is used for a traveling wave type ultrasonic motor. Therefore, even if the frequency is not changed, only by controlling the phase of the high-frequency AC voltage, it is possible to control the speed characteristics such that the speed becomes high when the movable body is driven in one direction and becomes low when the movable body is driven in the opposite direction. Can do it.

According to the fifth aspect of the present invention, the vibration wave of the stator is a standing wave, and this stator is used for a standing wave type ultrasonic motor. Therefore, even if the frequency is not changed, only by switching the supply destination of the high-frequency AC voltage, the speed characteristic becomes high when the movable body is driven in one direction and becomes low when the movable body is driven in the opposite direction. Control can be performed.

According to the sixth aspect of the invention, at least one of the side surfaces of the stator contact portion of the diaphragm in the moving direction of the movable body is inclined. Therefore, the vibration component of the vibration wave generated in the stator contact portion based on the driving of the piezoelectric element can be increased in one direction and reduced in the opposite direction due to the inclination of the side surface of the stator contact portion. As a result, the ultrasonic motor using this diaphragm can control the speed characteristics such that the speed becomes high when the movable body is driven in one direction and becomes low when the movable body is driven in the opposite direction, without changing the frequency. Can be performed.

According to the seventh aspect of the present invention, the ultrasonic motor has a high speed when the movable body is driven in one direction and a low speed when the movable body is driven in the opposite direction without changing the frequency. The following speed characteristics can be controlled.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment in which the present invention is embodied in a traveling wave type ultrasonic motor will be described below with reference to FIGS. As shown in FIG. 1, the stator 1 includes a vibration plate 2 and a piezoelectric element 3.

The diaphragm 2 is formed of an annular steel body, and the diaphragm 2 is formed with a plurality of protrusions 4 as stator contact portions in a comb-like shape. More specifically, as shown in FIG. 2, a plurality of projections 4 extending in the radial direction from the inner peripheral surface to the outer peripheral surface are formed on the diaphragm 2 in the circumferential direction by cutting or grinding. Then, as shown in the schematic diagram of FIG. 3, both side surfaces 4 a in the circumferential direction of each projection 4 viewed from the outer peripheral surface of the diaphragm 2.
Is inclined diagonally upward to the right in FIG.

An annular piezoelectric element 3 is fixed to the lower surface of the vibration plate 2. The piezoelectric element 3 is polarized by a known method for generating traveling wave vibration, and the piezoelectric element 3
Known electrode plates (not shown) are provided on the lower surface of each of the polarized portions in two groups. A voltage control device (not shown) for applying a high-frequency AC voltage is connected to the two sets of electrode plates.

A rotor 5 as a movable body is disposed above the stator 1. The rotor 5 includes an annular rotor body 6 and a lining material 7 fixed to a lower surface of the rotor body 6. The lower surface of the lining member 7 is pressed against the upper surface of each projection 4 of the diaphragm 2 so that the rotor 5 can slide and rotate on the stator 1.

The ultrasonic motor having the above-described structure is capable of controlling the two sets of electrode plates by 90 ° in time by the voltage control device.
When a high-frequency AC voltage having a phase difference is applied, the piezoelectric element 3 vibrates. This vibration is transmitted to the protrusions 4 of the diaphragm 2, and traveling wave vibration is generated on the upper surface of each protrusion 4, that is, the contact surface with the rotor 5. This traveling wave vibration causes the rotor 5
Rotates.

At this time, each of the projections 4 is formed on both sides 4 in the circumferential direction.
Since a is inclined in one direction (counterclockwise direction in FIG. 1), the traveling wave vibration has a large one-way vibration component on the side where each projection 4 is inclined. Accordingly, when the rotor 5 rotates in one direction on the side where the protrusion 4 is inclined, that is, when the rotor 5 rotates counterclockwise in FIG. 1, the ultrasonic motor rotates at high speed. Conversely, when the rotor 5 rotates in the other direction opposite to the inclined side, that is, when the rotor 5 rotates clockwise in FIG. 1, the vibration component is smaller than when the rotor 5 is rotated in the one direction. And the ultrasonic motor rotates at low speed. Therefore, the rotor 5 of the ultrasonic motor can be rotated at high speed in one direction and at low speed in the opposite direction only by controlling the phase of the high-frequency AC voltage without variably controlling the frequency.

Next, the features of the stator of the ultrasonic motor configured as described above will be described below. (1) In the first embodiment, each of the protrusions 4 has the circumferential side surfaces 4a inclined in one direction obliquely upward. Therefore,
The traveling wave vibration based on the driving of the piezoelectric element 3 has a large one-way vibration component on the side where the protrusion 4 is inclined. Therefore, when the rotor 5 rotates in one direction, the ultrasonic motor rotates at high speed, and when the rotor 5 rotates in the other direction, the ultrasonic motor rotates at low speed. As a result, even if the ultrasonic motor of the present embodiment cannot change the frequency, only by using a voltage control device that can control the phase of the high-frequency AC voltage, the motor rotates at high speed in one direction and rotates at low speed in the opposite direction. Become. As a result, when a motor having a rotation speed characteristic that is fast in one direction and slow in the reverse direction is required, the cost of the voltage control device can be reduced. Further, this ultrasonic motor can simply obtain high-speed rotation in one direction.

(Second Embodiment) A second embodiment in which the present invention is embodied in a traveling wave type ultrasonic motor will be described below with reference to FIGS. As shown in FIG. 4, the stator 11 includes a vibration plate 12, a base ring 13, and a piezoelectric element 14.

The diaphragm 12 is formed of an annular steel plate.
The diaphragm 12 has a plurality of protrusions 1 as a stator contact portion.
5 is formed in a comb shape. More specifically, the diaphragm 12
As shown in FIG. 5, by pressing a pair of comb-shaped press dies facing each other, and arranging and pressing each other so that the comb teeth are alternately arranged, a radial direction from the inner peripheral surface as shown in FIG. A plurality of protrusions 15 extending to the outer peripheral surface are formed in the circumferential direction, and a groove 16 is formed upward from a lower center of each protrusion 15. Then, as shown in the schematic diagram of FIG. 6, both circumferential side surfaces 1 of each projection 15 viewed from the outer circumferential surface of the diaphragm 12.
5a is slanted rightward and upward in FIG.

An annular base ring 13 is fixed to the lower surface of the diaphragm 12. An annular piezoelectric element 14 is fixed to the lower surface of the base ring 13. That is, the piezoelectric element 14 that generates vibration is hardly fixed to the vibration plate 12 in which the groove 16 is formed, so that it is fixed via the base ring 13. The piezoelectric element 14 is subjected to polarization processing by a known method for generating traveling wave vibration, and two sets of known electrode plates (not shown) are provided on the lower surface of each polarized portion of the piezoelectric element 14. They are provided in groups. A voltage control device (not shown) for applying a high-frequency AC voltage is connected to the two sets of electrode plates.

An annular rotor 1 is provided above the stator 11.
7 are provided. The rotor 17 includes an annular rotor body 18 and a lining material 19 fixed to the lower surface of the rotor body 18. The lower surface of the lining material 19 is pressed against the upper surface of each projection 15 of the vibration plate 12, and the rotor 17 can slide and rotate on the stator 11.

The ultrasonic motor having the above-described structure is capable of controlling the two sets of electrode plates by 90 ° in time by the voltage control device.
When a high-frequency AC voltage having a phase difference is applied, the piezoelectric element 14 vibrates. And this vibration is applied to the base ring 13
The traveling wave vibration is generated on the upper surface of each projection 15, that is, the contact surface with the rotor 17, via the projections 15 of the diaphragm 12. This traveling wave vibration causes the rotor 17 to rotate.

At this time, since each of the protrusions 15 has both circumferential side surfaces 15a inclined in one direction (counterclockwise direction in FIG. 4), traveling wave vibration is generated in one direction on the side where each protrusion 15 is inclined. Vibration component becomes large. Therefore, when the rotor 17 rotates in one direction on the side where the protrusion 15 is inclined,
When the rotor 17 rotates counterclockwise in FIG. 4, the ultrasonic motor rotates at high speed. Conversely, when the rotor 17 rotates in the other direction opposite to the inclined side, that is, when the rotor 17 rotates clockwise in FIG.
The vibration component is smaller than in the case of rotating in one direction, and the ultrasonic motor rotates at low speed. Accordingly, the rotor 17 of the ultrasonic motor can be rotated at a high speed in one direction and at a low speed in the opposite direction only by controlling the phase of the high-frequency AC voltage without variably controlling the frequency.

Next, the features of the stator of the ultrasonic motor configured as described above will be described below. (1) In the second embodiment, each of the protrusions 15 has both side surfaces 15a in the circumferential direction inclined in one direction. Therefore, the traveling wave vibration based on the driving of the piezoelectric element 14 has a large one-way vibration component on the side where the protrusion 15 is inclined. Therefore, when the rotor 17 rotates in one direction, the ultrasonic motor rotates at high speed, and when the rotor 17 rotates in the other direction, the ultrasonic motor rotates at low speed. As a result, even if the ultrasonic motor of the present embodiment cannot change the frequency, only by using a voltage control device that can control the phase of the high-frequency AC voltage, the motor rotates at high speed in one direction and rotates at low speed in the opposite direction. Become. as a result,
When a motor having a rotation speed characteristic that is fast in one direction and slow in the reverse direction is required, the cost of the voltage control device can be reduced. Further, this ultrasonic motor can simply obtain high-speed rotation in one direction.

(2) In the second embodiment, the plurality of projections 15 are formed by press working. Therefore, the production time can be reduced and the cost can be reduced as compared with the processing using cutting or grinding.

(3) In the second embodiment, each projection 15
A groove 16 is formed upward from the center of the lower part. Therefore, each projection 15 is further easily bent in the circumferential direction. As a result, each projection 15 can efficiently generate traveling wave vibration based on driving of the piezoelectric element 14.

(Third Embodiment) Next, a third embodiment in which the present invention is embodied in a standing wave type ultrasonic motor will be described with reference to FIGS. As shown in FIG. 7, the stator 21 includes a vibration plate 22 and a piezoelectric element 23.

The diaphragm 22 is formed of an annular steel body.
The diaphragm 22 has a plurality of protrusions 2 as stator contact portions.
4 are formed in a comb shape. More specifically, the diaphragm 22
In this example, twelve protrusions 24 extending from the inner peripheral surface to the outer peripheral surface in the radial direction are formed at equal intervals (each 30 ° interval) in the circumferential direction by cutting or grinding. Then, both side surfaces 24 a in the circumferential direction of each protrusion 24 as viewed from the outer peripheral surface of the diaphragm 22 are:
It is inclined to the upper right.

An annular piezoelectric element 2 is provided on the lower surface of the diaphragm 22.
3 is fixed. In the present embodiment, the piezoelectric element 23 is divided into twelve pieces and subjected to polarization processing in order to generate standing wave vibration. To be more specific, the piezoelectric element 23 is configured such that adjacent polarities are opposite to the first polarized region groups A1 to A5, which are polarized into five at equal intervals (each 30 ° interval) so that adjacent polarities are opposite. The second polarization region groups B1 to B5, which are polarized into five at equal intervals (each 30 ° interval), and the positions between both ends of the first polarization region groups A1 to A5 and the second polarization region groups B1 to B5, respectively. And the first and second feedback polarization regions F1 and F2. Note that the first feedback polarization region F1 has a wider circumferential interval than the second feedback polarization region F2.

The piezoelectric element 23 thus polarized
The positional relationship between the projections 24 and the projections 24 is as shown in the schematic diagram of FIG. FIG. 8A is a schematic diagram showing a circumferential interval of the piezoelectric element 23 developed on a straight line.
Each projection 24 corresponding to the first and second feedback polarization regions F1 and F2 is arranged at an intermediate position in each region. First and second polarization regions A1 to A
Each of the protrusions 24 corresponding to 5, B1 to B5 is arranged at a position closer to the first feedback polarization region F1 side than the intermediate position in each region.

An electrode plate (not shown) is provided on the lower surface of the piezoelectric element 23. Specifically, the first polarization region group A1
The first electrode plate is located at a position corresponding to .about.A5, the second electrode plate is located at a position corresponding to the second polarization region groups B1 to B5, and the feedback electrode plate is located at a position corresponding to the feedback polarization regions F1 and F2. Provided. A voltage controller (not shown) for applying a high-frequency AC voltage is connected to the first and second electrode plates. The feedback electrode plate is used for detecting information on the vibration generated in the piezoelectric element 23.

A rotor 25 as a movable body is disposed above the stator 21. The rotor 25 includes an annular rotor main body 26 and a lining material 27 fixed to the lower surface of the rotor main body 26. The lower surface of the lining material 27 is pressed against the upper surface of each projection 24 of the vibration plate 22 so that the rotor 25 can slide and rotate on the stator 21.

When the high frequency AC voltage is applied to the first electrode plate from the voltage control device, the ultrasonic motor having the above-described structure has the piezoelectric elements 23 at the positions of the first polarization region groups A1 to A5.
Vibrates, and the diaphragm 22 generates standing wave vibration as shown by the solid line and the broken line in FIG. Then, elliptical vibration occurs at the projection 24. Then, when the projection 24 comes into contact with the rotor 25 (when the peak of vibration occurs), the projection 24 acts to push the rotor 25 rightward in FIG. 8B. Therefore, the rotor 25 rotates counterclockwise.

At this time, each projection 24 is formed on both side surfaces 2 in the circumferential direction.
Since 4a is inclined in one direction (counterclockwise direction in FIG. 7), the elliptical vibration has a large horizontal vibration component when rotating in one direction. Accordingly, when the rotor 5 rotates in one direction on the side where the protrusion 24 is inclined, that is, when the rotor 25 rotates in the counterclockwise direction in FIG. 7, the ultrasonic motor rotates at high speed. In FIG. 8B, the vibration width of the vibration plate 22 is illustrated in a large scale for easy understanding of the operation.

Conversely, when a high-frequency AC voltage is applied to the second electrode plate from the voltage controller, the second polarization region groups B1 to B5
The piezoelectric element 23 at the position of FIG.
A standing wave vibration as shown by the solid line and the broken line in (C) is generated. Then, elliptical vibration occurs at the projection 24. And
When the projection 24 comes into contact with the rotor 25 (when the peak of vibration occurs), the projection 24 acts to push the rotor 25 leftward in FIG. 8C. Therefore, the rotor 2
5 rotates clockwise.

At this time, each projection 24 is formed on both side surfaces 2 in the circumferential direction.
Since 4a is inclined in one direction (counterclockwise direction in FIG. 7), the elliptical vibration has a smaller horizontal vibration component compared to the counterclockwise rotation. Therefore, when the rotor 5 rotates in the other direction opposite to the side where the protrusion 24 is inclined, that is, when the rotor 25 rotates clockwise in FIG. 7, the ultrasonic motor rotates at low speed. FIG. 8C
Here, the vibration width of the diaphragm 22 is illustrated in a large scale in order to easily explain the operation.

Next, features of the stator of the ultrasonic motor configured as described above will be described below. (1) In the third embodiment, each of the protrusions 24 has a circumferential side surface 24a which is inclined obliquely upward in one direction. Therefore, the elliptical vibration of the protrusion 24 based on the standing wave vibration is caused by the protrusion 2
The vibration component in the horizontal direction becomes larger when 4 is rotated to the inclined side. Therefore, when the rotor 25 rotates in one direction, the ultrasonic motor rotates at high speed, and when the rotor 25 rotates in the other direction, the ultrasonic motor rotates at low speed. As a result, even if the ultrasonic motor of the present embodiment cannot change the frequency, the ultrasonic motor in one direction can be used only by using the voltage control device capable of switching the supply destination (the first and second electrode plates) of the high-frequency AC voltage. High-speed rotation and low-speed rotation in the opposite direction are possible. As a result, when a motor having a rotation speed characteristic that is fast in one direction and slow in the reverse direction is required, the cost of the voltage control device can be reduced. Further, this ultrasonic motor can simply obtain high-speed rotation in one direction.

The above embodiment may be modified and implemented as follows. In the second embodiment, the vibration plate 12 has a plurality of projections 15 extending in the radial direction from the inner peripheral surface to the outer peripheral surface in the circumferential direction by press working. Grooves 16 are formed upward, and both circumferential side surfaces 15a of each projection 15 viewed from the outer circumferential surface of the diaphragm 12 are inclined counterclockwise in FIG.
It is not limited to this shape.

For example, as shown in FIGS. 9 to 11, the left side surface 32a in the circumferential direction of each projection 32 viewed from the outer peripheral surface of the diaphragm 31 is perpendicular, and the right side surface 32b is obliquely right upward. It may be inclined. With this configuration, it is possible to obtain the same effect as that of the second embodiment, and
Since the upper surface of the projection 32, that is, the contact surface with the rotor 17 is increased, the vibration of the stator 11 is efficiently transmitted to the rotor 17.

As shown in FIGS. 12 to 14, the right side surface 42a in the circumferential direction of each projection 42 as viewed from the outer peripheral surface of the diaphragm 41 is perpendicular, and the left side surface 42b is obliquely right upward. It may be inclined. According to this structure, the same effect as in the second embodiment can be obtained, and the press die can be easily pulled out in the press working, so that it can be easily manufactured.

In the first embodiment, the diaphragm 2
A plurality of projections 4 extending from the inner peripheral surface to the outer peripheral surface in the radial direction are formed in the circumferential direction by cutting or grinding, and the circumferential side surfaces 4a of the respective projections 4 as viewed from the outer peripheral surface of the diaphragm 2 are ,
Although it is assumed that it is inclined upward and obliquely to the right, it is not limited to this shape.

For example, as shown in the schematic diagram of FIG. 15, the left side surface 52a in the circumferential direction of each projection 52 viewed from the outer peripheral surface of the diaphragm 51 is perpendicular, and the right side surface 52b is obliquely right upward. It may be inclined. With this configuration, the first
The same effect as that of the first embodiment can be obtained, and the upper surface of the projection 52, that is, the contact surface with the rotor 5 is increased, so that the vibration of the stator 1 is efficiently transmitted to the rotor 5.

In the second embodiment, the diaphragm 12
The inclined projections 15 were formed by pressing a pair of comb-shaped press dies to face each other, and arranging and pressing the comb teeth alternately, as shown in FIG. First, by pressing, a projection 62 is formed vertically on the vibration plate 61, and after the press die is removed, the projection 62 is pressed from above to incline the circumferential side surface 62a of the projection 62. May be. When manufactured in this manner, the opening 6 of the groove 63 formed in the center of the lower portion of the projection 62
3a is crushed, the lower surface of the vibration plate 61 becomes substantially flat, and the piezoelectric element 14 can be directly adhered and fixed to the lower surface. Therefore, the base ring 13 becomes unnecessary,
Cost can be reduced. In FIG. 14, both side surfaces 62a are inclined in opposite directions. However, as described above, for example, only one side surface is inclined, and high-speed rotation is performed in one direction and low-speed rotation is performed in the opposite direction. You may do so.

In the third embodiment, the diaphragm 22
The shape of the projection 24 formed on the side surface is such that both side surfaces 24a in the circumferential direction are inclined in one direction, but at least one of the side surfaces 24a in the circumferential direction is inclined similarly to the traveling wave type ultrasonic motor. For example, each of the protrusions 1 described above may be used.
5, 32, 42, 52, and 62 may be protrusions having the same shape.

The standing-wave type ultrasonic motor according to the third embodiment is not limited to the above-described one, and may be one that generates an elliptical vibration on a projection by standing-wave vibration and moves a movable body. For example, any pattern such as a pattern having a different polarization processing of the piezoelectric element 23 may be used.

In the above embodiments, the vibration plates 2 and 1
Although 2, 22 are formed by any of cutting, grinding, and pressing, they may be formed by other manufacturing methods such as, for example, sintering.

In each of the above embodiments, the rotors 5, 17, and 25 and the stators 1, 11, and 21 as movable bodies are formed in an annular shape, and are ultrasonic motors that perform rotational motion. May be formed as a linear ultrasonic motor formed linearly. In this case, the projections formed on the diaphragm tilt the side surfaces in the direction in which the movable body is moved. In this way, even if a voltage control device that cannot change the frequency is used, the ultrasonic motor can move at high speed in one direction and move at low speed in the opposite direction. As a result, when a linear motor having a speed characteristic that is fast in one direction and slow in the reverse direction is required, the cost of the voltage control device can be reduced. Further, this linear ultrasonic motor can simply move the movable body in one direction at a high speed.

The technical ideas other than the claims that can be grasped from the above embodiments will be described below together with their effects. (A) In the stator of the ultrasonic motor according to any one of claims 1 to 5, the stator contact portion (15,
32. A stator for an ultrasonic motor, wherein grooves (16, 63) are formed in the lower part of (32, 42, 62). In this case, the stator contact portion is easily bent in the circumferential direction. Therefore, the stator contact portion can efficiently generate a vibration wave based on the driving of the piezoelectric element.

(B) In the stator of the ultrasonic motor according to (a), the groove (63) has an opening (6).
A stator for an ultrasonic motor, wherein 3a) is formed so as to be closed on the same plane as the lower surface of the diaphragm (61). This makes it possible to directly fix the piezoelectric element to the lower surface.

[0057]

As described in detail above, according to the present invention,
It is possible to provide an ultrasonic motor stator, a diaphragm, and an ultrasonic motor that can obtain desired speed characteristics without requiring complicated AC voltage control.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining an ultrasonic motor according to a first embodiment.

FIG. 2 is a perspective view of the stator according to the first embodiment with a part cut away.

FIG. 3 is a schematic view of the stator according to the first embodiment viewed from an outer peripheral surface.

FIG. 4 is an explanatory diagram for explaining an ultrasonic motor according to a second embodiment.

FIG. 5 is a perspective view of the stator according to the second embodiment with a part cut away.

FIG. 6 is a schematic view of a stator according to a second embodiment viewed from an outer peripheral surface.

FIG. 7 is an explanatory diagram for explaining an ultrasonic motor according to a third embodiment.

FIG. 8A is a schematic view of a stator according to a third embodiment developed in a circumferential direction. (B) Explanatory drawing for demonstrating operation | movement of the stator of 3rd Embodiment. (C) Similarly, explanatory drawing for demonstrating operation | movement of the stator of 3rd Embodiment.

FIG. 9 is an explanatory diagram for explaining another example of an ultrasonic motor.

FIG. 10 is a perspective view in which a stator of another example is partially cut away.

FIG. 11 is a schematic view of another example of a stator viewed from an outer peripheral surface.

FIG. 12 is an explanatory diagram for explaining another example of an ultrasonic motor.

FIG. 13 is a perspective view in which a stator of another example is partially cut away.

FIG. 14 is a schematic view of another example of a stator viewed from an outer peripheral surface.

FIG. 15 is a schematic view of another example of a stator viewed from an outer peripheral surface.

FIG. 16 is a schematic view of another example of a stator viewed from an outer peripheral surface.

[Explanation of symbols]

2, 12, 22, 31, 41, 51, 61 ... diaphragm
3, 14, 23 ... piezoelectric element, 4, 15, 24, 32, 4
2, 52, 62 ... projection, 5, 17, 25 ... rotor, 4
a, 15a, 24a, 32a, 32b, 42a, 42
b, 52a, 52b, 62a...

Claims (7)

[Claims] A plurality of standing stator contact portions (4, 15, 24, 3) that come into contact with a movable body (5, 17, 25).
2, 42, 52, 62)
2, 31, 41, 51, 61) and the diaphragm (2, 12, 22, 31, 41, 51, 6)
1), and is provided below the stator contact portion (4, 1).
5, 24, 32, 42, 52, 62) and a piezoelectric element (3, 14, 23) for generating a vibration wave, wherein the stator contact portion (4, 15, 24) is provided. , 32,42,5
2, 62) are both side surfaces (4a, 15a, 24a, 32a, 32b, 42a, 4a) in the direction in which the movable body is moved.
2b, 52a, 52b, 62a), wherein at least one side surface is inclined. 2. The stator for an ultrasonic motor according to claim 1, wherein said movable body (5, 17, 25) and said diaphragm (2, 1).
2, 22, 31, 31, 41, 51, 61) and the piezoelectric element (3, 14, 23) are formed in an annular shape. 3. The stator for an ultrasonic motor according to claim 1, wherein the diaphragm (12, 31, 41, 61) having the stator contact portion (15, 32, 42, 62) is An ultrasonic motor stator formed by press working. 4. The stator for an ultrasonic motor according to claim 1, wherein the vibration wave is a traveling wave. 5. The stator for an ultrasonic motor according to claim 1, wherein the vibration wave is a standing wave. 6. A plurality of standing stator contact portions (4, 15, 24, 3) which come into contact with a movable body (5, 17, 25).
2, 42, 52, 62), and the stator contact portions (4, 15, 24, 32, 42, 5)
2, 62) are both side surfaces (4a, 15a, 24a, 32a, 32b, 42a, 4a) in the direction in which the movable body is moved.
2b, 52a, 52b, 62a), wherein at least one side surface is inclined. 7. An ultrasonic motor comprising the stator according to claim 1. Description: