JPS61191277A - Elastic wave motor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an elastic wave motor in which a rotor is driven by elastic waves generated in an elastic body.

[Summary of the invention]

The present invention is characterized by providing a human phase and a B phase having a phase difference of 7 from each other over substantially the entire circumference of a ring-shaped elastic body, and an elastic wave that increases the driving area and improves wavelength selectivity. It's a motor.

[Conventional technology]

Figures 6 and 7 are based on a rotary elastic wave motor, and the theoretical tζ
It shows.

In FIGS. 6 and 7, a ring-shaped elastic body 1 made of metal or the like has a ring-shaped rotor 2 on one side.
are in contact with each other, and piezoelectric bodies 31 to 31o are bonded to the other one. In addition, + attached to each piezoelectric body 31 to 31o,
- indicates the polarization direction in the thickness direction.

Piezoelectric bodies 31 to 35. A phase A is formed, and one pair is made up of a piezoelectric body of 10 and a piezoelectric body of -, and 2.5 pairs are provided in the illustrated case. The length λ of one period is selected to be equal to the wavelength λ of the drive signal So. The piezoelectric bodies 36 to 31o form the B phase and have the same configuration as the phase input described above. Also, the input phase and B phase are each 1
They are arranged with a mechanical phase difference of λ.

In the above configuration, the drive signal source 4 sends a drive signal SO having a frequency determined by the wavelength λ to the B-phase piezoelectric body 3.
6 to 31o, and a drive signal S1 obtained by shifting the phase of this drive signal So by 90 degrees by a phase shifter 5 is applied to the piezoelectric bodies 31 to 31o of the human phase.
Add to 35. As a result, vibrations of wavelength λ are generated in the part 1 corresponding to the human face of the elastic body 1 as shown by the solid line in FIG. A vibration with a wavelength λ and a phase difference between the A-phase vibration and Iλ is generated. This vibration causes the rotor 2 to rotate on the elastic body 1. If the drive signals So and 81 are interchanged, the phase relationship of the human-phase vibration and the B-phase vibration in FIG. 8 will be reversed as shown in FIG. 9, and the rotation direction of the rotor 2 will be reversed.

Additionally, the present applicant has specifically identified the invention related to the elastic wave motor as 1.
It has been proposed in Application No. 58-21206, etc.

[Problem that the invention seeks to solve]

In the case of the above-mentioned elastic wave motor shown in FIG. 6, the phase input drive area is only 5/12 of the entire piezoelectric adhesive surface of the elastic body 1, and the input area is small. This is the same even if the B phase 1 is stuck. In addition, the drive source from the above 5/12 part and the remaining 7
/12, the wavelength selectivity deteriorates, and as a result, unnecessary vibration components other than the target wavelength λ are mixed in the required vibration mode. Sometimes. As shown in Figure 6, enter phase and B.
An ineffective portion corresponding to two wavelengths, a portion of 4/3λ and a portion of 1/4λ, is formed between the phase and the phase.

For the above reasons, the required vibration is suppressed to a small level, and in order to obtain large power, it is necessary to increase the voltage applied to the piezoelectric body.

[Means for solving problems]

In the present invention, the in-phase and the B-phase are each provided over the entire circumference of the ring-shaped elastic body.

[Effect]

The larger the driving area, the better the wavelength selectivity.
)7 Become.

[Implementation row]

FIG. 1 shows a first embodiment of the present invention, and parts corresponding to those in FIGS. 6 and 7 are given the same reference numerals.

In FIG. 1, a piezoelectric material 31 is provided on one surface of the elastic body 1.
A phase B consisting of piezoelectric bodies 315 to 324 is provided over the entire circumference, and on the other surface opposite to the surface on which this human phase is provided, a phase B consisting of piezoelectric bodies 315 to 324 is provided with a phase difference of λ They are provided with a phase difference of . Further, a vibration transmitting portion 1a is formed with a predetermined width on the inner side of the elastic body 1.
``L, The rotor 2 is in contact with this vibration transmitting part 1a.The same drive circuit as the conventional one is used, and in this example, the drive signal SO is supplied to the input phase, and the drive signal SO is rotated by 90 degrees. The phase-shifted drive signal S1 is supplied to the B phase.

FIG. 2 shows a second embodiment, in which a vibration transmitting portion 1b of a predetermined width is provided on the outside of the elastic body 1, and the rotor 2 is brought into contact therewith. Note that the other parts are constructed the same as in FIG. 1.

FIG. 3 shows a third embodiment, in which the input phase and B phase are
A vibration transmitting portion 1C of a predetermined width is provided on one surface of the elastic body 1 over the entire circumference, and between the input phase and the B phase. It goes without saying that the vibration transmitting section may be provided inside the elastic body 1 as shown in FIG. 1, or may be provided outside as shown in FIG. In addition, on both sides of the elastic body 1, a human face and B
A phase can also be provided.

FIG. 4 shows a fourth embodiment, in which a first phase input and a second phase input are provided overlappingly on one surface of the elastic body 1, and
This is a case where the first B phase and the second B phase are provided on the other side. In addition, although the vibration transmission part 1a is provided on the inside in the illustration, it may be provided on the outside.

In addition, in the first to fourth embodiments, the vibration transmitting parts la, l
b. The IC may be omitted, the piezoelectric surface may be coated, and the rotor 2 may be brought into pressure contact with the piezoelectric surface through this coating layer.

In the first to fourth implementation rows described above, the A phase and B phase
Since each phase is provided over the entire circumference of the elastic body 1, the driving area is significantly larger than that of the conventional structure. Furthermore, since the driving sources formed by each piezoelectric body are distributed evenly over the entire circumference, the necessary vibration can be increased, and the wavelength selectivity is improved, so that unnecessary vibration components are reduced. Therefore, the shape output ratio of the motor can be increased and the motor can be driven efficiently with low voltage.

FIG. 5 shows a specific embodiment in which the elastic wave motor of FIG. 1 according to the first embodiment described above is made into a hollow cylindrical structure.

In FIG. 5, a ring-shaped frame 10 having seven flange 10a integrally formed at one end has seven flange ll
A cylindrical body 11 having an integrally formed body 11 is screwed together through a threaded portion 12 formed therebetween.

On the outside of the frame 10, a ring-shaped elastic r6s made of brass fathom is provided. On both upper and lower surfaces of this elastic body 1, there are three piezoelectric bodies forming a phase input and a piezoelectric body 3B forming a B phase.
are glued to each other. These three piezoelectric bodies 3n are composed of a plurality of piezoelectric bodies 31 to 312, 313 to
324 is arranged.

A damper 14 made of felt or the like is provided between the piezoelectric bodies 3A, 3n and the seven flange 10a. A parallel plate 15 with a smooth upper surface and a pressure member 16 made of rubber or the like are laminated. Further, a slider plate 11, a damper 18, a rotor 2, etc. are stacked between the elastic body 1 and the 7 flange lla, and the rotor 2 and the flange lla
A bearing 19 is interposed between the two. Therefore,
Due to the screw engagement between the frame body 10 and the cylinder body 11 and the elasticity of the pressure member 16, the gap between the seven flange 10a and lla is
Each of the above members is clamped with appropriate pressure.

The damper 18 is designed to prevent unnecessary vibrations from being transmitted to the rotor 2, and is designed to transmit only the driving force generated by the bending vibration of the elastic body 1 to the rotor 2I via the vibration transmitting portion 1a. There is. Further, the outer diameter of the five-rotor 2 is larger than the outer diameters of other members.

The above configuration constitutes a hollow Kawasaki type elastic wave motor.

By appropriately supplying the drive signal 80% S to the piezoelectric body 3M+3a of this motor in the manner described with reference to Fig. #11, vibration is generated in the elastic body 1, and this vibration is transmitted from the vibration transmitting part 1a. It is transmitted to the rotor 2 via the slider 17 and the damper 18. This rotating field force can be taken out from, for example, the outer peripheral edge portion of the rotor 2.

〔Effect of the invention〕

As the driving area becomes larger, the driving source increases over the entire circumference of the elastic body.
Since they are evenly distributed throughout, the necessary vibration can be increased, wavelength selectivity is improved, and unnecessary vibration components are reduced. Therefore, the motor output ratio can be increased and the motor can be driven efficiently with low voltage.

[Brief explanation of drawings]

1lc1 to 4 are diagrams showing a plane, a side surface, and a drive circuit of an elastic wave motor showing first to fourth embodiments of the present invention, respectively;
Fig. 5 is a side cross-sectional view showing an embodiment of a hollow cylindrical motor; Fig. 6 is a plan view showing the principle of a rotary acoustic wave motor; Fig. 7 is a side view of Fig. 6; 9 and 9 are vibration waveform diagrams. In addition, in the symbols used in the drawings, 1...
・・・・・・Ring-shaped elastic body 2 ・・・・・・・・・
...Rotor 3, -312...Piezoelectric bodies 313-32 constituting A@
4...Piezoelectric body 4 constituting phase B...
...Drive source 5 .........90° phase shifter.

Claims (1)

[Claims] A first phase in which a plurality of piezoelectric bodies are arranged so that the polarization directions in the thickness direction of two adjacent piezoelectric bodies are opposite to each other is provided over substantially the entire circumference of the ring-shaped elastic body. In addition, a second phase configured similarly to the first phase is provided over substantially the entire circumference of the elastic body with a mechanical phase difference of 90° with respect to the first phase. Features an elastic wave motor.