JP2005176522A - Vibrating actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibrating actuator stabilized in performance from an initial stage of assembling, and reducible in cost. <P>SOLUTION: The vibrating actuator 10A comprises: a vibrator 11; a rotor 15A that pressure-contacts with the vibrator 11 and rotates; an elastic member 20 that rotates together with the rotor 15A and is arranged to a contact face between the vibrator 11 and the rotor 15A in parallel therewith; a shaft 18 that rotates together with the elastic member 20; and a pressurizing means 19 or the like that makes the rotor 15A pressure-contact with the vibrator 11. The rotor 15A has a sliding part 15a and an elastic member contact part 15b, the elastic member contact part 15b has the same radius as that of the sliding part 15a, and a position in the radial direction wherein the rotor 15A and the elastic member 20 contact with each other and a position in the radial direction wherein the vibrator 11 and the rotor 15A contact with each other are made to be almost equal. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vibration actuator having an improved structure of a rotating body (rotor) portion.

FIG. 5 is a diagram for explaining a conventional vibration actuator and its problems.
The vibration actuator 10 includes a vibrator 11 and a rotor 15, the vibrator 11 side is fixed, and the rotor 15 side is rotationally driven.

  The vibrator 11 includes a stator 12 and an electromechanical conversion element (hereinafter referred to as a piezoelectric body) 13 that is joined to the stator 12 and takes an example of a piezoelectric element or an electrostrictive element that converts electrical energy into mechanical energy. Has been. A traveling wave (for example, nine traveling waves) is generated in the vibrating body 11. In addition, a flexible printed circuit board (FPC) 14 for supplying a driving voltage is connected to the lower surface of the piezoelectric body 13.

  The stator 12 is made of a metal material having a high resonance sharpness, and has a ring shape. The stator 12 is provided with comb teeth 12a having grooves formed on the opposite surface to which the piezoelectric body 13 is joined. The tip surface serves as a driving surface and is in pressure contact with the rotor 15. The reason for forming the comb teeth 12a is to amplify the amplitude of the traveling wave on the driving surface by bringing the neutral surface of the traveling wave as close as possible to the piezoelectric body 13 side.

  The piezoelectric body 13 is divided into two phases (A phase and B phase) along the circumferential direction, and in each phase, the elements in which polarization is alternated every 1/2 wavelength are arranged, There is an interval of 1/4 wavelength between the A phase and the B phase.

  The rotor 15 is made of a light metal such as aluminum, and the surface of the sliding surface is subjected to a surface treatment for improving wear resistance.

  The stator 12 has a flange portion 12b formed on the inner periphery thereof, and is attached to the stator mount 16 with the flange portion 12b. A shaft 18 is rotatably attached to the stator mount 16 via a bearing 17. A rotor 15 is attached to the tip of the shaft 18.

  The pressurizing unit 19 is a unit that pressurizes the rotor 15 against the stator 12, and is provided on the shaft 18. The pressurizing means 19 is disposed in contact with the spring 19 a, the bearing 17, a press ring 19 b that presses one end of the spring 19 a, a press ring 19 c that presses the other end of the spring 19 a, and a groove formed in the shaft 18. And an E-ring 19b that regulates the position of the holding ring 19c.

  However, the conventional vibration actuator 10 described above has a problem that when the rotor 15 is brought into pressure contact with the vibrator 11, the surface pressure of the sliding portion 15a becomes non-uniform and the performance is not stable. In the example of FIG. 5, pressure is applied to the inside of the rotor 15, so that the surface pressure is higher on the inner side than on the outer side of the sliding portion 15 a. For this reason, the inner wear of the sliding portion 15a progresses quickly, and thereafter, the sliding portion 15a has a uniform surface pressure over the entire surface and the performance is stabilized.

In order to solve this problem, in Patent Document 1, the sliding surface is tapered by a surface grinder or the like in a state where a working pressure larger than the driving pressure is applied.
However, this method requires a tool for performing surface grinding while applying pressure, leading to an increase in cost.
Japanese Patent Laid-Open No. 11-113272

  An object of the present invention is to provide a vibration actuator that has stable performance from the initial stage of assembly and can reduce costs.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to the Example of this invention is attached | subjected and demonstrated, it is not limited to this.
According to the first aspect of the present invention, there is provided a vibrating body (11), a rotating body (15A) that rotates by being in pressure contact with the vibrating body, a rotating surface that rotates together with the rotating body, and a contact surface between the vibrating body and the rotating body. An elastic member (20) disposed in parallel with the elastic member, a rotating member (18) that rotates together with the elastic member, and a pressurizing member (19) that pressurizes and contacts the rotating body with the vibrating body, A vibration actuator characterized in that a radial position (15b) where the rotating body and the elastic member contact each other and a radial position (15a) where the vibrating body and the rotating body contact each other are substantially equal. is there.

  A second aspect of the present invention is the vibration actuator according to the first aspect, wherein the elastic member and the rotating member are integrated.

  A third aspect of the present invention is the vibration actuator according to the first or second aspect, further comprising a friction member (21) having a high friction coefficient disposed between the rotating body and the elastic member. This is a vibration actuator.

  According to a fourth aspect of the present invention, there is provided a vibrating body (11), a rotating body (15B) that rotates by being in pressure contact with the vibrating body, a rotating member (18) that rotates together with the rotating body, and the rotating body. A pressure member (19) that pressurizes and contacts the vibrating body, wherein the rotating body (15B) includes a sliding portion (15c) that contacts the vibrating body, and a contact between the sliding portion and the vibrating body. A disk-like elastic portion (15d) extending in a direction parallel to the surface, and a flexible portion (15e) formed between the sliding portion and the elastic portion, which is more flexible than the elastic portion. This is a characteristic vibration actuator.

As described above, according to the present invention, the radial position where the rotating body and the elastic member are in contact with the radial position where the vibrating body and the rotating body are in contact with each other is substantially equal. Even if the deformation due to pressurization is expanded, the deformation of the elastic member is not transmitted to the rotating body, and the contact surface pressure between the vibrating body and the rotating body becomes uniform immediately after assembly.
Further, since the rotating body is formed with a flexible part that is more flexible than the elastic part between the sliding part and the elastic part, the flexible part deforms like a hinge, and the inclination of the elastic part becomes the sliding part. Since it is difficult to transmit, the contact surface pressure between the vibrating body and the rotating body becomes uniform immediately after assembly.
For this reason, the performance is stabilized with a short aging time, and the aging time is shortened, so that the cost is reduced.

  The present invention aims to make the contact surface pressure between the vibrating body and the rotating body uniform, and separates the sliding portion constituting the rotor and the portion extending in the pressurizing direction from the portion parallel to the sliding surface. It is realized by applying pressure with a radius substantially equal to the sliding portion of the rotor, or by providing a portion of the rotor thinner than the disc portion.

Hereinafter, the present invention will be described in more detail with reference to the drawings and the like.
FIG. 1 is a cross-sectional view illustrating an assembled state of a vibration actuator according to a first embodiment of the present invention, and FIG. 2 is a diagram illustrating the operation of the vibration actuator according to the first embodiment.
In the following embodiments, an ultrasonic motor using an ultrasonic vibration region will be described as an example of a vibration actuator.
Moreover, in each Example shown below, the part which fulfill | performs the same function as the prior art example mentioned above attaches | subjects the same code | symbol or the code | symbol unified at the end, and abbreviate | omits the description and drawing which overlap suitably.

  The vibration actuator 10A according to the first embodiment is arranged in parallel with the vibrator 11, the rotor 15A that rotates by being in pressure contact with the vibrator 11, the rotor 15A, and the contact surface between the vibrator 11 and the rotor 15A. Provided with an elastic member 20, a shaft 18 that rotates together with the elastic member 20, and a pressurizing unit 19 that pressurizes and contacts the rotor 15 </ b> A with the vibrator 11.

  The rotor 15A includes a sliding portion 15a and an elastic member contact portion 15b, each having a step of about 0.2 mm. The elastic member contact portion 15b has the same radius as the sliding portion 15a. That is, in the vibration actuator 10A, the radial position where the rotor 15A and the elastic member 20 are in contact with the radial position where the vibrator 11 and the rotor 15A are in contact is approximately equal.

  As the material of the rotor 15A, a material obtained by blending fibers into PEEK resin or PPS resin is preferably used. In addition, aluminum may be alumite-treated, or other metal material may be Ni-plated as necessary. Further, the rotor 15A is preferably subjected to surface polishing before assembly in order to smooth the sliding portion 15a.

  The elastic member 20 is a member that rotates together with the rotor 15 </ b> A and is disposed in parallel to the contact surface between the stator 12 of the vibrating body 11 and the rotor 15 </ b> A, and is integrally provided at the upper end of the shaft 18. A friction member 21 having a high coefficient of friction such as rubber is sandwiched between the elastic member 20 and the rotor 15A, and the elastic member 20 and the shaft 18 together with the rotor 15A are generated by the frictional force generated by the pressing force of the pressurizing means 19. Rotates.

  The vibration actuator 10A according to the first embodiment becomes as illustrated in FIG. 2 when the deformation due to the pressurization of the pressurizing unit 19 is enlarged, and the deformation of the elastic member 20 is not transmitted to the rotor 15A, but the contact between the vibrator 11 and the rotor 15A. The surface pressure becomes uniform.

As described above, according to the first embodiment, since the contact surface pressure between the vibrator 11 and the rotor 15A becomes uniform immediately after assembly, the performance is stabilized in a short aging time, and the aging time is shortened. Can be planned.
In addition, since the amount of wear during planar polishing or aging can be reduced, the friction material (including surface treatment such as plating and alumite) of the rotor 15A can be made thin, so that the cost can be further reduced. is there.

FIG. 3 is a sectional view showing an assembled state of the vibration actuator according to the second embodiment of the present invention, and FIG. 4 is a diagram for explaining the operation of the vibration actuator according to the second embodiment.
The vibration actuator 10B according to the second embodiment includes the vibrator 11, the rotor 15B that rotates by being in pressure contact with the vibrator 11, the shaft 18 that rotates together with the rotor 15B, and the rotor 15B that is in pressure contact with the vibrator 11. Pressure means 19 and the like.

  The rotating body 15B includes a sliding portion 15c that contacts the vibrating body 11, a disk-shaped elastic portion 15d extending in a direction parallel to a contact surface between the sliding portion 15c and the vibrating body 11, a sliding portion 15c, and an elastic portion. 15d, and a flexible portion 15e that is more flexible than the elastic portion 15d.

  In the vibration actuator 10B according to the second embodiment, since the thin flexible portion 15e provided on the rotor 15B is deformed like a hinge, the inclination of the disk-like elastic portion 15d of the rotor 15B is not easily transmitted to the sliding portion 15c. Therefore, when the deformation due to the pressurization of the pressurizing means 19 is enlarged, the contact surface pressure between the vibrator 11 and the rotor 15B becomes uniform as shown in FIG.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention.
For example, in the first embodiment, a notch (not shown) is provided on the outer periphery of the elastic member 20 and is fitted with a protrusion provided on the rotor 15A so that the rotor 15A, the elastic member 20 and the shaft 18 rotate together. May be.

It is sectional drawing which shows the assembly state of Example 1 of the vibration actuator by this invention. It is a figure explaining operation | movement of the vibration actuator by Example 1. FIG. It is sectional drawing which shows the assembly state of Example 2 of the vibration actuator by this invention. It is a figure explaining operation | movement of the vibration actuator by Example 2. FIG. It is a figure for demonstrating the conventional vibration actuator and its problem.

Explanation of symbols

10A, 10B Vibration actuator 11 Vibrator 12 Stator 13 Piezoelectric body 14 Flexible printed circuit board (FPC)
15A, 15B Rotor 15a Sliding part 15b Elastic member contact part 15c Sliding part 15d Elastic part 15e Flexible part 16 Stator mount 17 Bearing 18 Axis 19 Pressing means 20 Elastic member 21 Friction member

Claims (4)

A vibrating body,
A rotating body that rotates in pressure contact with the vibrating body;
An elastic member that rotates together with the rotating body and is arranged in parallel to a contact surface between the vibrating body and the rotating body;
A rotating member that rotates with the elastic member;
A pressing member that pressurizes and contacts the rotating body with the vibrating body;
With
The radial position where the rotating body and the elastic member contact each other and the radial position where the vibrating body and the rotating body contact each other are substantially equal;
Vibration actuator characterized by The vibration actuator according to claim 1,
The elastic member and the rotating member are integral;
Vibration actuator characterized by The vibration actuator according to claim 1 or 2,
Comprising a friction member having a high coefficient of friction disposed between the rotating body and the elastic member;
Vibration actuator characterized by A vibrating body,
A rotating body that rotates in pressure contact with the vibrating body;
A rotating member that rotates together with the rotating body;
A pressure member that pressurizes and contacts the rotating body to the vibrating body,
The rotating body is
A sliding portion in contact with the vibrating body;
A disc-shaped elastic portion extending in a direction parallel to the contact surface between the sliding portion and the vibrating body;
A flexible part formed between the sliding part and the elastic part, which is more flexible than the elastic part;
A vibration actuator comprising:

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