JPH0787759A - Stator of ultrasonic motor - Google Patents

Abstract

PURPOSE:To obtain a motor which is easy of working operation, expands the vibrating amplitude of traveling waves generated at a stator, turns a rotor with high efficiency, shortens the working time of the stator, and reduces cost. CONSTITUTION:A stator 10 for an ultrasonic motor is constituted of piezoelectric elements 14a, 14b which are formed to be ring-shaped, of a vibration generation source which is composed of the piezoelectric elements 14a, 14b and of an elastic body 15 and of disk-shaped support plates 13a, 13b which support the vibration generation source and which produce traveling waves by the bend vibration of the vibration generation source. In the stator, grooves 30 which are passed in the thickness direction of the support plates 13a, 13b are formed in the radial direction of the support plates 13a, 13b, and elastic pieces 31 are installed.

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 stator capable of obtaining vibration efficiently at low cost.

[0002]

2. Description of the Related Art As a stator of a conventional ultrasonic motor,
For example, there is a vibration wave motor disclosed in Japanese Examined Patent Publication No. 4-77553.

Electrostrictive elements are provided on both sides of the vibrator of this vibration wave motor. Then, the moving body is pressed against the vibrator in the portion apart from the electrostrictive element. When a predetermined high frequency voltage is applied to the electrostrictive element, its electric energy is converted into vibration energy. Then, a unidirectional traveling wave is generated in the stator due to the vibration energy,
The moving body moves in the direction opposite to this traveling wave via frictional force.

Generally, in order to increase the torque of the motor, it is necessary to increase the vibration amplitude of the traveling wave generated in the stator and increase the pressing force of the moving body pressed by the stator.

Here, a stator of an ultrasonic motor for the purpose of enlarging the vibration amplitude of the traveling wave generated in the stator to increase the torque of the motor has been proposed as shown in FIGS. The stator 81 includes a support portion 82, a thin portion 83, a vibration generating portion 84, a protrusion 85, and a pair of piezoelectric elements 86a and 86b. That is, the thin portion 83 is formed on the outer peripheral surface of the support portion 82, and the vibration generating portion 84 is formed on the outer periphery of the thin portion 83. Further, a protrusion 85 protruding vertically is formed on the outer periphery of the vibration generating portion 84. In addition, the pair of piezoelectric elements 86a and 86b
Are attached to the upper and lower surfaces of the vibration generating portion 84.

Therefore, when a voltage is applied to the piezoelectric elements 86a and 86b to vibrate the vibration generating portion 84, the vibration is efficiently transmitted to the projection 85 because the thin portion 83 does not transmit the vibration to the supporting portion 82. Further, since the upper and lower amplitudes of the vibration are enlarged by the projection 85, the rotor (not shown) rotates and the output can be improved by the double vibration force.

[0007]

However, the projections 85 of the stator 81 are precisely formed by cutting, and
Since it is formed with high precision, there is a problem that the working time is very long and the processing cost increases. For example, the protrusion 85
There are 72 stators on one side of the stator 81, and these are at positions facing each other by 180 °. In this case, it takes about 3 minutes to move the end mill of the milling machine in the diametrical direction and make the projection 85. Therefore, the manufacturing time for forming the protrusions 85 on both surfaces of the stator 81 requires 72 × 3 = 216 minutes≈3 hours. Therefore, a huge amount of time and a processing machine are dedicated to manufacturing the stator 81 for a long time, which causes a problem of cost increase.

Further, even when the thin portion 83 is formed, it is precisely formed by cutting, which causes a problem that the processing cost is further increased. The present invention has been made to solve the above-mentioned problems, and its purpose is to facilitate the machining operation, expand the vibration amplitude of the traveling wave generated in the stator to rotate the rotor efficiently, and further reduce the machining time of the stator. It is an object of the present invention to provide a stator of an ultrasonic motor having a novel structure that can shorten the cost and reduce the cost.

[0009]

In order to solve the above problems, a first aspect of the present invention provides a piezoelectric element formed in an annular shape and a vibration source including the piezoelectric element and an elastic body.
In a stator of an ultrasonic motor configured to support the vibration source and a disc-shaped support member that generates a traveling wave by bending vibration of the vibration source, the support member is provided in the radial direction of the support member. The gist of the present invention is to form a groove penetrating in the thickness direction of the above and to provide an elastic piece.

According to a second aspect of the present invention, a vibration generating member having a disc shape, a circular pressure contact plate provided in pressure contact with an outer peripheral surface of the vibration generating member, and the vibration generating member and the pressure contact plate. In a stator of an ultrasonic motor composed of a ring-shaped piezoelectric element provided on a vibration generator other than a portion where the pressure contact plate is pressed, the pressure contact plate penetrates in the thickness direction of the pressure contact plate in the radial direction. The gist is that a groove is formed and an elastic piece is provided.

[0011]

According to the first aspect of the invention, since the elastic piece is provided by forming the groove penetrating in the thickness direction of the support member in the radial direction of the support member, the elastic piece is elastic by the bending vibration of the vibration source. A traveling wave is transmitted to the piece. Further, the elastic property of the elastic piece expands the vibration amplitude of the traveling wave.

The groove of the supporting member is easily formed by punching such as press working. According to the invention described in claim 2, since the elastic piece is provided by forming the groove penetrating in the thickness direction of the pressure contact plate in the radial direction of the pressure contact plate, the bending of the piezoelectric element attached to the vibration generator is provided. The traveling wave is transmitted to the elastic piece by the vibration. Further, the elastic property of the elastic piece expands the vibration amplitude of the traveling wave.

The groove of the pressure contact plate is easily formed by punching such as press working.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention is shown in FIG.
A description will be given based on FIG. As shown in FIG. 1, a main body case 1 constituting an ultrasonic motor is composed of a base 2 and an upper cover 3, and the base 2 and the upper cover 3 form a storage space portion 4. A cylindrical mounting portion 5 is formed on the upper surface of the center of the base 2 so as to project therefrom, and an insertion hole 6 is formed in the center of the base 2, and a base of the rotary shaft 7 is inserted through the insertion hole 6. The end is inserted into the storage space 4. or,
The rotating shaft 7 is rotatably supported by a bearing 8 arranged in the insertion hole 6. Furthermore, a cover recess 3a is formed in the upper cover 3. This cover recess 3a
A bearing 9 is disposed in the bearing 9, and the base end of the rotary shaft 7 is rotatably supported by the bearing 9. Further, a shaft fitting portion 7a having a flat surface portion formed on the surface of the rotating shaft 7.
And a flange 7b are formed.

The circular stator 1 is provided on the upper surface of the mounting portion 5.
0 is placed, and the stator 10 is fixedly attached to the placing portion 5 with screws 11. A through hole 12 is formed at the center of the stator 10, and the through hole 12
The rotary shaft 7 is inserted through the.

The stator 10 is made of chrome-molybdenum steel and has a pair of support plates 13a and 13b as support members, and a pair of ring-shaped piezoelectric elements 14a and 14b.
It is composed of a ring-shaped metallic elastic body 15 and an insulating plate 16 made of circular bakelite.

The pair of support plates 13a, 13b are base portions 17a, 17b placed on the placing portion 5, and vibrating portions 18a, 18 protruding on the outer circumferences of the base portions 17a, 17b.
b and. Also, a pair of support plates 13a, 1
Half of the radius of 3b is the radius of the base portions 17a and 17b. Further, in this embodiment, the vibrating parts 18a and 18b are used.
Is thinner than the bases 17a and 17b.

The pair of support plates 13a and 13b are superposed on each other, and the insulating plate 16 is disposed between the base portions 17a and 17b of the pair of support plates 13a and 13b.
The pair of support plates 13a and 13b are electrically insulated by the insulating plate 16.

An elastic body 15 having a pair of piezoelectric elements 14a and 14b attached to the upper and lower surfaces thereof is disposed on the outer periphery between the vibrating portions 18a and 18b of the pair of support plates 13a and 13b. An electrode layer (not shown) is formed on the upper surface of the piezoelectric element 14a. Similarly, an electrode layer (not shown) is formed on the lower surface of the piezoelectric element 14b. The elastic body 15 is grounded by a ground wire (not shown). Then, high frequency voltages having a 90 ° phase difference are applied to the respective electrode layers of the pair of piezoelectric elements 14a and 14b. Therefore, the piezoelectric element 14a,
A short circuit of the high frequency voltage applied to 14b is prevented.

A metallic rotor 20 made of aluminum or the like is mounted on the upper surface of the stator 10. That is, the ring-shaped pressure contact surface 2 that is in sliding contact with the outer peripheral surface of the support plate 13a of the stator 10 is provided on the outer periphery of the rotor 20.
1 is formed to project. A lining material (wear-resistant Teflon-based resin) 22 is provided on the pressure contact surface 21 on the lower surface side of the rotor 20. In addition, an insertion hole 23 is provided at the center of the rotor 20. The shaft fitting portion 7a of the rotary shaft 7 is inserted into the insertion hole 23. Further, the rotor 20 and the rotating shaft 7 are engaged with each other in the rotating direction, and when the rotor 20 is rotated, the rotating shaft 7 is integrally rotated.
The rotor 20 can move in the axial direction of the rotary shaft 7.

A pressing plate 24 abutting against the flange 7b is inserted into the shaft fitting portion 7a of the rotary shaft 7,
The rotating shaft 7 and the pressing plate 24 are fixed in the rotating direction. The pressing plate 24 is movable in the axial direction of the rotary shaft 7. An elastic member 25 is arranged on the lower surface of the pressurizing plate 24, and the elastic member 25 is in contact with the rotor 20 via a vibration-proof rubber 26. Further, a washer 27 is provided on the rotary shaft 7 to abut the flange 7b, and the washer 27 is abutted to the bearing 9.

Therefore, the pressurizing plate 24 has the elastic member 2
5, the rotor 20 is pressed downward via the rubber 5 and the anti-vibration rubber 26. Therefore, the rotor 20 is placed in a state of being pressed against the upper surface of the stator 10 via the lining material 22. Then, due to the bending vibrations of the piezoelectric elements 14a and 14b, the rotor 20 is subjected to frictional force in a direction opposite to the one-way traveling wave generated in the pair of support plates 13a and 13b.
Also, the rotary shaft 7 is adapted to rotate. The pressing force can be adjusted by changing the thickness of the washer 27.

As shown in FIGS. 1 and 2, a pair of support plates 1
The vibrating portions 18a and 18b of 3a and 13b are
Grooves 3 are formed at predetermined intervals so as to penetrate in the thickness direction of a and 18b.
0 is formed in the radial direction of the support plates 13a and 13b, and the groove 30 forms a plurality of elastic pieces 31.
Further, the number and width of the grooves 30 are determined so that 2 to 8 elastic pieces 31 are included in one wavelength of the traveling wave generated by the bending vibration of the piezoelectric elements 14a and 14b.

Further, since the groove 30 is formed in the vibrating portions 18a and 18b, the length of the elastic piece 31 in the radial direction is approximately half the length of the radius of the pair of support plates 13a and 13b. There is.

Since the pair of piezoelectric elements 14a and 14b are different from each other in position by 90 ° and are arranged in the elastic body 15 in a state where the phases are different by 90 ° from each other, when a high frequency voltage is applied, the piezoelectric elements 14a and 14b are arranged. 14a and 14b perform bending motion to convert electric energy into vibration energy. This vibration energy is transferred to the elastic piece 3 of the pair of support plates 13a and 13b.
Propagate to 1. Further, the elastic property of the elastic piece 31 expands the vibration amplitude, and the expanded vibration amplitude causes the rotor 20 to vibrate and rotate by receiving a frictional force.

Next, the operation of the ultrasonic motor configured as described above will be described. When a high-frequency voltage having a phase difference of 90 ° is applied to the piezoelectric elements 14a and 14b from a drive circuit (not shown), the piezoelectric elements 14a and 14b expand and contract to generate bending vibration. Therefore, the piezoelectric element 1
4a and 14b convert electric energy into vibration energy. The amplitude of the bending vibration of the piezoelectric elements 14a and 14b is expanded by the elastic body 15 and the vibrating portions 18a and 18b.
Due to this vibration, a unidirectional traveling wave is generated in the elastic piece 31 of the vibrating portions 18a and 18b. This traveling wave is transmitted to the pressure contact surface 21 of the rotor 20. Therefore, the rotor 20 rotates via frictional force in the direction opposite to the traveling wave in one direction.

Further, due to the elastic property of the elastic piece 31, the vibration amplitude of the traveling wave is expanded, the traveling wave allows the rotor 20 to rotate efficiently, and the output of the ultrasonic motor can be improved.

Further, the support plates 13a and 13b and the vibrating section 1
By devising the shapes of 8a and 18b, the base portion 1
Since the vibration can not be transmitted to 7a and 17b, the traveling wave generated in the support plates 13a and 13b can be efficiently transmitted to the rotor 20. As a result, the output of the ultrasonic motor 1 can be improved.

Further, even if an external force or a pressing force from the rotor 20 or the like is applied to the elastic piece 31 of the stator 10, the vibrating portions 18a and 18b absorb the unnecessary force due to the elastic property, so that the vibration is stable. Can be driven.

Further, the vibrating portion 18 of the support plates 13a and 13b.
The elastic piece 31 formed on a and 18b is formed by the groove 30. The groove 30 can be easily formed by punching such as pressing. That is, since the grooves 30 formed in the vibrating portions 18a and 18b can be formed at once by pressing, the support plates 13a and 13b having the elastic pieces 31 formed by the grooves 30 can be manufactured in a few minutes.

After that, if the surfaces of the support plates 13a and 13b having the grooves 30 formed by press working are finished with a polishing machine, it can be completed in a few minutes. As a result, unlike the prior art, it is possible to facilitate the manufacturing of the support plates 13a and 13b, shorten the manufacturing time, and suppress the cost.

Further, since the length of the radius of the elastic piece 31 formed on the support plates 13a, 13b is set to be approximately 1/2 of the radius of the support plates 13a, 13b, it is generated by the bending vibration of the piezoelectric elements 14a, 14b. The amplitude of the traveling wave can be efficiently expanded. That is, when the length of the elastic piece 31 in the radial direction is longer than 1/2 of the radius of the support plates 13a and 13b, unnecessary vibration irrelevant to the vibration amplitude received by the elastic piece 31 easily occurs. On the contrary, when the radial length of the elastic piece 31 becomes shorter than 1/2 of the radius of the support plates 13a and 13b, the elastic property of the elastic piece 31 decreases. Therefore, the vibration amplitude of the traveling wave cannot be efficiently expanded.

Incidentally, base portions 17a and 17b having a radius of 45 mm and a thickness of 2 mm are formed on a pair of support plates 13a and 13b having a radius of 60 mm, and vibrating portions 18a and 18b.
Thickness is 2 mm. Also, the thickness of the elastic body 15 is 2 mm.
The thickness of the piezoelectric elements 14a and 14b is set to 0.5 mm, and the width of the groove 30 is set to about 2 mm to form the sweater 10.

The dynamic admittance characteristic which is an electric characteristic of this stator 10 was measured. As a result, the value of dynamic admittance was 13 ms to 15 ms. On the other hand, the dynamic admittance characteristic of the conventional stator 81 having a diameter of 67 mm was measured. As a result, the value of dynamic admittance was 15 ms to 20 ms.

As a result, the characteristics of the conventional stator 81 are better, but the diameters of the stator 10 and the stator 81 are different, and the diameter of the stator 81 is larger. Therefore, it is considered that the value of the dynamic admittance is improved by the increase in the diameter of the stator 81. Therefore, if the stator 10 has the same diameter as the conventional stator, the stator 1
The characteristic of dynamic admittance of 0 can be improved.

Further, a double-exposure hologram is formed by using a double-pulse laser light source in which the rotor is in contact with the contact surface of the stator 10 of the present invention in a vibrating state and a stationary state, and an interference fringe corresponding to the vibration amplitude is obtained. The vibration appearance was observed.

From these results, it was confirmed that the vibration mode of the vibration wave was observed on the elastic piece 31, and that the vibration amplitude increased toward the outer circumference. Therefore, it was found that the vibrational amplitude of the traveling wave was surely expanded due to the elastic property of the elastic piece 31. Further, no striped pattern is seen on the base portions 17a and 17b, and the vibration from the elastic piece 31 is generated by the vibration portions 18a and 18b.
It was found that it was blocked by b so that it was not reliably transmitted.

The elastic force of the elastic piece 31 can be improved by subjecting the support plates 13a and 13b of this embodiment to heat treatment, surface treatment, shot peening (strain peening), or the like.

Further, although the support plates 13a and 13b are made of chromium molybdenum steel, in addition to this, for the purpose of further improving the elastic force of the elastic piece 31, spring steel, phosphor bronze, beryllium copper, constant elastic spring alloy, It is also possible to form the support plates 13a and 13b from stainless steel or the like.

Next, the stator 1 constructed as described above
It is also possible to change the various members forming 0 as follows. The same members as those in the above-mentioned embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 3, a pair of support plates 13a,
The thickness of the base portions 17a and 17b of 13b and the thickness of the elastic piece 31 formed by the groove 30 are made the same. In addition, a slanted portion 33 is formed in the elastic piece 31 substantially at the center thereof by expanding. Then, the elastic body 15 and the piezoelectric elements 14a and 14b attached to both surfaces of the elastic body 15 are arranged at the tips of the elastic pieces 31 expanded by the inclined portion 33. Then, the rotor 20 is pressed against the outer peripheral surface of the stator 10 whose thickness direction is increased.

In this case, since the thickness direction of the tip of the elastic piece 31 can be increased by the slanted portion 33 of the elastic piece 31, the thickness of the piezoelectric elements 14a, 14b and the elastic body 15 can be increased. . As a result, the piezoelectric elements 14a,
The traveling wave bending vibration based on the expansion and contraction of 14b can be expanded.

Further, since the slanted portion 33 can be formed during the punching press forming for forming the groove 30, the manufacturing time of the support plates 13a and 13b does not become long.
Further, as shown in FIG. 4, it is possible to form the crank portions 34 in the elastic pieces 31 in the direction away from each other so as to obtain the same effect as described above.

As shown in FIG. 5, a pair of support plates 13a,
The thickness of the base portions 17a and 17b of 13b and the thickness of the elastic piece 31 formed by the groove 30 are made the same. Further, the vibration suppressing plate 35 is provided on both upper and lower surfaces of the pair of support plates 17a and 17b.
Attach and fix a and 35b.

The support plate 13 is attached to the vibration suppressing plates 35a and 35b.
A groove 36 corresponding to the groove 30 formed in a and 13b is formed to form a suppressing piece 37. The radial length of the restraining piece 37 is shorter than the radial length of the elastic piece 31. Then, the rotor 20 is brought into pressure contact with the elastic piece 31 that is not covered by the suppressing piece 37.

With this configuration, the piezoelectric elements 14a, 14b
It is possible to reliably prevent the traveling-wave flexural vibration due to the expansion and contraction from being transmitted to the base portions 17a and 17b through the elastic piece 31. As a result, the vibration amplitude of the traveling wave generated in the elastic piece 31 can be efficiently expanded and transmitted to the rotor 20, so that the output of the ultrasonic motor can be improved.

In the present embodiment, the lining material 22 is provided on the pressure contact surface 21 on the lower surface side of the rotor 20, but as shown in FIG. 6, the lining material 22 is attached to the upper end surface of the elastic piece 31 of the support plate 13a. May be. Therefore, the vibration amplitude of the traveling wave can be expanded by the thickness of the lining material 22. It is also possible to provide an additional mass instead of the lining material 22 for increasing the amplitude.

Further, as shown in FIG. 7, a pair of support plates 1
The base portions 17a and 17b and the vibrating portions 18a and 18b in 3a and 13 have the same thickness. When the groove 30 is formed by press working, a recess 38 is formed on the base side of the elastic piece 31 on the upper surface side of the support plate 13a and on the base side of the elastic piece 31 on the lower surface side of the support plate 13b. A projection 39 in the thickness direction is formed at the tip of the.

Since the height of the elastic piece 31 can be increased by forming the protrusion 39, the vibration amplitude of the traveling wave can be increased. Further, traveling wave bending vibration is generated by the recess 38 formed in the elastic piece 31 in the bases 17a, 1a.
By providing an acoustic gap so as not to transmit to 7b, it can be surely prevented.

As a result, the flexural vibration of the traveling wave generated in the elastic piece 31 is surely expanded by the projection 39, and the vibration amplitude can be transmitted to the rotor 20 to improve the output of the ultrasonic motor. You can

As a modification of FIG. 7, as shown in FIG. 8, a recess 38 formed on the base side of the elastic piece 31 may be formed on the opposing surface side where the support plates 13a and 13b face each other. Good. Further, in FIG. 8, a slit 32 is provided in the traveling wave bending vibration transmitting portion of the elastic piece 31, and the elastic piece 31 is subdivided to improve vibration followability. The elastic pieces 31 are subdivided into the support plates 13a, 1 of all the embodiments of the present invention.
3b can be applied.

In this embodiment, since the processing width of the groove 30 is constant, the elastic piece 31 is made wider toward the outer periphery. However, as shown in FIG. By changing the width, all the elastic pieces 31 may have the same width, or as shown in FIG. 10, the elastic pieces 31 may be formed so that the width becomes smaller toward the outer circumference.

In addition to this, as a variation of a good shape, as shown in FIG. 11, bent portions 40 that are bent inward are formed on both sides in the center width direction of the elastic piece 31, or
As shown in FIG. 12, curved portions 41 that curve inward may be formed on both sides of the elastic piece 31 in the width direction. With this configuration, it is possible to prevent unnecessary vibration from being transmitted from the elastic piece 31 to the base portions 17a and 17b.

Further, as shown in FIGS. 13 and 14, the groove 3
The base portion of 0 may be formed with the arc portion 42, or the base portion of the groove 30 may be formed with the round hole 43. With this configuration, the elastic piece 31
It is possible to protect the support plates 13a and 13b and improve the reliability by preventing the stress of unnecessary vibration generated from the above from concentrating on the base of the groove 30.

In this embodiment, a pair of support plates 13
a, 13b, a pair of piezoelectric elements 14a, 14b, elastic body 1
5 and the insulating plate 16 constitute the stator 10. In addition to the above, as shown in FIG. 15, elastic elements in which piezoelectric elements 14a and 14b are attached to the upper and lower surfaces of the outer peripheral lower surface of one support plate 13a in which elastic pieces 31 are formed by the grooves 30 are provided as necessary. The rotor 10 may be configured to attach the body 15. Further, the vibration source does not have to be composed of the piezoelectric elements 14a and 14b and the elastic body 15, but may be one in which one piezoelectric element and a laminated body of piezoelectric elements are arranged.

Further, as shown in FIG. 16, a fixed portion 51,
A vibration generator 54 including a thin portion 52 provided on the outer periphery of the fixed portion 51 and a vibration expanding portion 53 provided on the outer periphery of the thin portion 52 is fixed to the mounting portion 5. Further, the piezoelectric elements 14a and 14b are attached to both upper and lower surfaces of the vibration enlarging portion 53. Further, the base portion 17a of the support plate 13a as a pressure contact plate is attached and fixed to the upper surface of the fixed portion 51 of the vibration generator 54. Grooves 30 are formed in the support plate 13a and elastic pieces 31 are formed. Further, the elastic piece 31 is formed with a slant portion 55 for avoiding interference with the piezoelectric element 14a. Further, a protrusion 56 is formed on the lower surface of the tip of the elastic piece 31, and the protrusion 56 is pressed against the upper surface of the vibration enlarging portion 53 to which the piezoelectric element 14a is not attached.

Also with this structure of the vibration generator 54, when the piezoelectric elements 14a and 14b expand and contract, the vibration amplitude of the bending vibration due to the expansion and contraction is expanded by the vibration expanding portion 53 and the projection 56. Further, the traveling wave due to the bending vibration is transmitted to the elastic piece 31, and the vibration amplitude thereof can be expanded by the elastic property of the elastic piece 31.

[0058]

As described in detail above, according to the present invention,
This has an excellent effect that the machining work is easy, the vibration amplitude of the traveling wave generated in the stator is expanded to rotate the rotor efficiently, and the machining time of the stator is short, so that the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an ultrasonic motor of the present invention.

FIG. 2 is a partial cross-sectional perspective view showing a stator of an ultrasonic motor according to the present invention.

FIG. 3 is a partial cross-sectional perspective view showing the structure of another example of a stator.

FIG. 4 is a partial cross-sectional perspective view showing a configuration of another example of a stator.

FIG. 5 is a partial cross-sectional perspective view showing the structure of another example of a stator.

FIG. 6 is a partial cross-sectional perspective view showing the structure of another example of a stator.

FIG. 7 is a partial cross-sectional perspective view showing the structure of another example of a stator.

FIG. 8 is a partial cross-sectional perspective view showing the structure of another example of a stator.

FIG. 9 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 10 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 11 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 12 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 13 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 14 is a partial plan view showing another example of the shape of the elastic piece formed by the groove on the support plate.

FIG. 15 is a partial cross-sectional perspective view showing a configuration of a stator of another example.

FIG. 16 is a partial cross-sectional cross-sectional view showing the structure of a stator of another example.

FIG. 17 is a perspective view showing a configuration of a conventional stator.

FIG. 18 is a cross-sectional view showing the structure of a conventional stator.

[Explanation of symbols]

10 ... Stator, 13a, 13b ... Support plate as a support member, 13a ... Support plate as a pressure contact plate, 14a, 14b
... Piezoelectric element that constitutes the vibration source, 15 ... Elastic body that constitutes the vibration source, 30 ... Groove, 31 ... Elastic piece, 54 ... Vibration generator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ayasu Kuwakazu, Nagakute-cho, Aichi-gun, Aichi Prefecture, Nagatoji, 1st 41st side street, Toyota Central Research Institute Co., Ltd. (72) Inventor Noboru Handa 390 Umeda, Kosai City, Shizuoka Prefecture Asmo stock company (72) Inventor Takashi Fukui 390 Umeda, Kosai city, Shizuoka prefecture Asmo stock company (72) Inventor Yoshihiro Adachi 390 Umeda city, Kosai city, Shizuoka prefecture Asmo stock company

Claims (2)

[Claims] 1. A piezoelectric element formed in an annular shape, a vibration source composed of the piezoelectric element and an elastic body, and a disc supporting the vibration source and generating a traveling wave by bending vibration of the vibration source. In a stator of an ultrasonic motor composed of a support member having a shape of a circular shape, an elastic piece is provided by forming a groove penetrating in a thickness direction of the support member in a radial direction of the support member. Sonic motor stator. 2. A disk-shaped vibration generating member, a circular pressure contact plate provided so as to press contact with an outer peripheral surface of the vibration generating member, and a portion where the vibration generator and the pressure contact plate are pressure contacted. In a stator of an ultrasonic motor composed of an annular piezoelectric element provided on a vibration generator other than the elastic piece, a groove penetrating in the thickness direction of the pressure contact plate is formed in the radial direction of the pressure contact plate. A stator of an ultrasonic motor, characterized by being provided with.