JP2544505Y2 - Ultrasonic motor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor, and more particularly to a structure for preventing slippage when a rotational force is externally applied to an output shaft while the motor is stopped.

[0002]

2. Description of the Related Art Conventionally, as this type of ultrasonic motor,
The cross section is, for example, as shown in FIG. In the figure, a stator 2 of an ultrasonic motor 1 is formed by forming an elastic body 3 such as a metal in an annular shape and joining a plurality of ultrasonic vibrators 4 thereto. It comprises an annular rotor portion 6 that frictionally slides on the surface of the elastic body 3 and an output shaft 7.

Reference numeral 8 denotes a dish-shaped spring, which is a sheet-shaped rubber plate 9.
, The annular rotor portion 6 of the rotor 5 is pressed against the elastic body 3 by a certain force. The annular rotor 6
A thin sheet-like slider (not shown) is inserted between the elastic member 3 and the elastic member 3. In addition, reference numeral 10 denotes a spring receiver of the disc spring 8, reference numeral 11 denotes a bearing, and reference numeral 12 denotes a casing.

When each element of the ultrasonic vibrator 4 is sequentially excited by a high frequency voltage having a certain phase difference, the longitudinal vibration and the horizontal vibration generated by each element are combined, and the elastic body 3
A traveling wave is generated in one direction on the surface of. For this reason, the annular rotor portion 6 of the rotor 5 is driven to slide by the frictional force with the elastic body 3, and mechanical output is taken out from the output shaft 7.

[0005]

However, in the conventional ultrasonic motor 1 described above, when a rotational force is applied to the output shaft 7 from the outside while the motor is stopped, the displacement gradually occurs. There was a problem. That is, when the load is raised or lowered by winding or unwinding a wire from the output shaft 7 via a pulley, the motor 1
When the position is held by its own static friction, the position may be gradually shifted.

[0006] This displacement is caused by the rotation of the rotor 5 and the rubber plate 9.
This is because slippage occurs between the three members of the disc-shaped spring 8, and when the slippage is repeated, the rubber plate 9 moves off the center of the rotating body and the disc-shaped spring 8 is moved. And the spring 8 may fall off from the spring receiver 10.

[0007] The present invention has been made in view of such a point,
An object of the present invention is to provide an ultrasonic motor which solves the above-mentioned problem and prevents a displacement between the rotor and the disc spring.

[0008]

In order to achieve the above object, the present invention comprises a stator in which an electro-ultrasonic conversion element is joined to the back surface of an annular elastic body, Pressed by a disc-shaped spring , an annular rotor
An output shaft with an axis at the center of the annular rotor
Rotor and the disk and the disc-shaped spring
It consists of a rubber plate, and exciting the transducer at a high frequency voltage to generate a traveling wave in the elastic body surface, the annular rotary
In the ultrasonic motor which frictionally slides children, the dish-shaped spring
A projection is provided on the disk side of
Lock holes are provided in the disc and rubber plate portions, and the protrusions are
And the disk-shaped spring and the annular rotor portion are locked .

[0009]

Since the present invention is constructed as described above, there is no displacement between the annular rotor and the rubber plate and the disc spring, and the annular rotor and the disc spring are fixed. It does not give adverse effect on the vibration and motor characteristics of the annular rotor so no. In addition, the rubber plate interposed between the annular rotor portion and the disc-shaped spring is the same as the conventional annular rotor.
It has the function of absorbing vibration of the part .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. FIG. 1 is a sectional view showing a first embodiment of the ultrasonic motor according to the present invention. 5, the same members as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1, an annular rotor of the rotor 5 is shown.
The part 16 includes a disk 19 and an annular rotor 20 provided around the disk 19.
Consists of The rubber plate 9 is disposed on the disk 19,
A disc-shaped spring 18 is pressed between the rubber plate 9 and the spring support 10.
It is provided in a contracted state. The portion close to the annular rotor 20 of the annular rotor portion 16 of the dish-shaped spring 18, provided eyelet
You. Then, a small screw 52 such as a round, flat, or round flat is inserted into the small hole so that the screw head faces the annular rotor portion 16 side.
Insert and fasten with the nut for small screw 51.
Attach to the spring 18 .

On the other hand, the disk 19 and the annular rotor portion 16
A through hole 16a is provided in the rubber plate 9 at a position facing a screw head which is a protrusion of the small screw 52, and the screw head of the small screw 52 is inserted into the through hole 16a. The annular rotor 16 and the rubber plate 9 are engaged with each other to
The spring 18 and the annular rotor 16 are locked.

FIG. 2 is a sectional view showing a second embodiment of the present invention, which is a modification of FIG. That is, a round rivet 53 is attached to a small hole provided in the dish-shaped spring 28 in the same manner as described above, with the rivet head facing the annular rotor portion 26 side, and the annular rivet 53 is opposed to the annular rotator portion 26 to face the rivet. The rivet head of the rivet 53 is engaged in the through hole 26a provided, so that the disc spring 28 and the annular rotor portion 26 are engaged.

FIGS. 3 (a) and 3 (b) are a plan view and a sectional view of a main part of a disk spring according to a third embodiment of the present invention. 4 (a) and 4 (b) are a plan view and a sectional view of an essential part of a dish-shaped spring showing a modification of the embodiment.

3 (a), 3 (b), 4 (a) and 4 (b), projections 38a formed by bending downwards are provided at portions near the outer peripheral edges of the disc-shaped springs 38 and 48. , 48
a, and opposed to the positions of the projections 38a, 48a,
Through holes 36a, 4
6a is provided. Then, the projections 38a, 48a are engaged with the through holes 36a, 46a, respectively, so that the disc-shaped springs 38, 48 and the annular rotor portions 36, 46 are engaged, respectively.

The technique of the present invention is not limited to the technique in the above-described embodiment, but may be implemented by means of another embodiment having the same function. Can be changed or added.

[0017]

As is clear from the above description, according to the ultrasonic motor of the present invention , a projection is provided on the disc-shaped spring, and
Part was engaged with the locking hole provided on the disc and rubber plate.
The role played by conventional rubber plates, for example, annular rotor and plate
When the spring is fixed, the components of each motor change over time.
It is possible to prevent a displacement between the rotor and the disc-shaped spring while keeping the occurrence of a change from occurring .

Therefore, wear of the rubber plate interposed between the rotor and the disc-shaped spring is extremely reduced, and it is possible to prevent the pressing force of the disc-shaped spring from being insufficient and from falling off from the spring receiver. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a first embodiment of an ultrasonic motor according to the present invention;

FIG. 2 is a sectional view illustrating a second embodiment of the present invention.

FIGS. 3 (a) and 3 (b) are a plan view and a sectional view of a main part of a disc spring showing a third embodiment of the present invention.

FIGS. 4 (a) and 4 (b) are a plan view and a sectional view of a main part of a dish-shaped spring showing a modification of the third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional ultrasonic motor.

[Explanation of symbols]

 2 Stator 3 Elastic body 4 Ultrasonic vibrator 5 Rotor 7 Output shaft 9 Rubber plate 16, 26, 36, 46 Annular rotor part 16a, 26a, 36a, 46a Through hole 18, 28, 38, 48 Disc spring 19 disk 20 annular rotor 38a, 48a bending projection 51 nut 52 machine screw 53 round rivet

Claims (1)

(57) [Scope of request for utility model registration] An electric-power- supplying device is provided on the back surface of an annular elastic body.
A stator 2 joined ultrasonic transducer 4, the elastic body 3
The ring-shaped rotor is pressed against the surface of the disk by springs 18, 28, 38, and 48, and is provided with an annular rotor 20 on the periphery of the disk 19.
Output having an axis at the center of the subunits 16, 26, 36, 46
Rotor 5 having shaft 7, disk 19 and disc spring 1
8, 28, 38, and 48, and the conversion element 4 is excited with a high-frequency voltage to generate a traveling wave on the surface of the elastic body 3 , and the annular rotor 20
An ultrasonic motor that frictionally slides the disc-shaped spring 1
8, 28, 38, 48, the projections 38a, 4
8a, 52, 53, and the projections 38a, 4
8a, 52, and 53 correspond to disk 19 and rubber plate 9
Are provided with locking holes 16a, 26a, 36a, 46a,
The projections 38a, 48a, 52, 53 are engaged with the locking holes 16a,
26a, 36a, and 46a, and a disc-shaped spring
18, 28, 38, 48 and annular rotor portions 16, 26, 3
An ultrasonic motor in which 6, 46 are locked .