JPH01214272A - Piezoelectric motor - Google Patents

Abstract

PURPOSE:To provide a piezoelectric motor having a simple structure and a light weight by combining a piezoelectric element and springs. CONSTITUTION:A motor driver 6 is rotatably provided on a stationary shaft 3 in a housing 1. A rotor 7 is composed of a bottomed cylinder 7a and an output shaft 7b, and rotatably provided through bearings 2 in the housing 1. A piezoelectric element 8 is so provided as to connect the driver 6 to the rotor 7, and is telescopic radially of the housing 1. A piezoelectric element 9 applies a unidirectional rotary force to the driver 6, and is driven in the same frequency as that of the element 8. When power is supplied to the piezoelectric elements, the elements 8, 9 are elongated to connect the driver 6 to the rotor 7, and the driver 6 rotates against the elastic force of a spring 10. When the elements 8, 9 are contracted, the driver 6 is separated from the rotor 7, and the driver 6 is reset by the spring 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piezoelectric motor used as a rotational drive source.

[Conventional technology]

Conventionally, motors used as rotational drive sources utilize the magnetic attraction force generated by the magnetic field generated by energizing a coil! Magnetic two are known.

[Problem to be solved by the invention]

However, since this type of electromagnetic motor uses coils and magnets, it has a complex structure and is not only heavy, but also complicated to assemble, and it is difficult to use in precision electronic equipment where electromagnetic waves have a negative effect. There was a problem that it was not suitable for integration into.

The present invention was developed in view of the above circumstances, and is based on a novel system that can obtain rotational driving force by repeating the expansion and contraction motion of the piezoelectric element, thereby eliminating the problems caused by the electromagnetic motor described above. The present invention provides a piezoelectric motor.

[Means to solve the problem]

A piezoelectric motor according to the present invention includes a drive body that is rotatably provided in a bearing housing and has a base that extends in the axial direction, an arm that extends to the side of the base, and a drive body that is disposed on the same axis as the drive body. a rotating body having a body that is rotatably disposed on the body and has a body facing the base; a first piezoelectric element capable of connecting the rotating body and the driving body is provided between the base and the body; A second piezoelectric element that expands and contracts at the same frequency as the frequency is provided between the bearing housing and the arm, and the second piezoelectric element applies rotational force to the driving body, and a spring applies a restoring force. It is something.

[For production]

In the present invention, when a current having the same frequency is supplied to the first piezoelectric element and the second piezoelectric element, the rotating body and the driving body are connected by the expansion of the piezoelectric elements, and the driving body is moved by the elastic force of the spring. The rotating body rotates against the force, and the rotating body and the driving body are separated by the contraction of the piezoelectric element, and the driving body is returned to its initial position by the elastic force of the spring.

[Example] Hereinafter, the structure of the present invention will be explained in detail with reference to an example shown in the drawings.

FIGS. 1(a) and (bl are a cross-sectional view taken along the a-a line and a cross-sectional view taken along the b-b line in FIG. 2, and FIG. 2 is a vertical cross-sectional view showing the piezoelectric motor according to the present invention. In the same figure, Reference numeral 1 denotes a housing having a bearing 2, which is entirely formed of a step-shaped cylinder with a bottom, and a fixed shaft 3 extending in the axial direction is integrally provided at the center bottom. , the inner peripheral surface of this housing 1 has four grooves 4 that open toward the center.
are provided at intervals of 90''. 5 is the bearing 2
an annular lid that holds an opening 1 in the housing 1;
It is provided to block a. Reference numeral 6 denotes a motor drive body, which includes a base 6a extending in the axial direction and a base 6a extending in the axial direction.
The arm 6b is provided radially (on the side of the base 6a) and has its tip facing into the groove 4, and is rotatably provided on the fixed shaft 3 in the housing 1. Reference numeral 7 denotes a rotary body of a motor, which is composed of a bottomed cylinder 7a with a flange serving as a body portion from which a part of the base 6a faces, and an output shaft 7b provided at the center of this bottomed cylinder 7a. It is located on the same axis as the housing 1 and is rotatably provided in the housing 1 via the bearing 2. Reference numeral 8 denotes a first piezoelectric element capable of connecting the driving body 6 and the rotary body 7, and the base portion 6a
are provided at intervals of 90'' around the periphery of the housing 1, and are configured to expand and contract in the radial direction of the housing 1.
is a second piezoelectric element that expands and contracts at the same frequency as this piezoelectric element 8, is provided in the groove wall 4a of the groove 4, and is configured to apply rotational force in one direction to the drive body 6. There is. Reference numeral 10 denotes a spring that imparts a return behavior to the driving body 6, and is elastically loaded between the groove wall 4a of the groove 4 and the arm 6b.

In the piezoelectric motor configured in this way, when currents having the same frequency (same phase) are supplied to the first piezoelectric element 8 and the second piezoelectric element 9, the results shown in FIGS. 3(a) and (b)
), the piezoelectric element 8.9 extends to connect the driving body 6 and the rotating body 7, and the driving body 6 is connected to the spring 10.
rotates against the repulsive force of.

On the other hand, when the intervening piezoelectric elements 8 and 9 contract, the driving body 6 and the rotating body 7 are separated from each other, and the driving body 6 is returned to its initial position by the elastic force of the spring 10.

Therefore, in the present invention, rotational driving force in a fixed direction can be obtained by repeating the expansion and contraction operations of the first piezoelectric element 8 and the second piezoelectric element 9.

Note that the shape and number of each component of the piezoelectric motor in the present invention are not limited to the above-described embodiments, and may be modified or changed as appropriate depending on, for example, the equipment used.

〔Effect of the invention〕

As explained above, according to the present invention, there is provided a drive body that is rotatably provided in a bearing housing and has a base that extends in the axial direction and an arm that extends to the side of the base, and a drive body that is identical to the drive body. a rotating body that is rotatably provided on the axis of the rotor and has a body that faces the base; a first piezoelectric element that can connect the rotating body and the driving body is provided between the base and the body; A second piezoelectric element that expands and contracts at the same frequency as the first piezoelectric element is provided between the bearing housing and the arm, and the second piezoelectric element applies rotational force to the drive body, and the spring returns the drive body. Since a force is applied, when a current with the same frequency is supplied to the first piezoelectric element and the second piezoelectric element, the rotating body and the driving body are connected by the expansion of both piezoelectric elements, and the driving body is moved by the spring. The rotating body rotates against the force of the bullet 18, and when both piezoelectric elements contract, the rotating body and the driving body are separated from each other, and the driving body is returned to its initial position by the upward movement of the spring. Therefore, rotational driving force can be obtained by repeating the expansion and contraction operations of both piezoelectric elements, which simplifies the structure compared to conventional electromagnetic motors.

The overall weight can be reduced and assembly work can be simplified. Further, since the present invention does not obtain rotational driving force by generating a magnetic field, it is extremely effective when applied to precision electronic equipment where electromagnetic waves have an adverse effect.

[Brief explanation of the drawing]

Figure 1 (al and ka) is a sectional view taken along line a-a in Figure 2 and b.
2 is a longitudinal sectional view showing the piezoelectric motor according to the present invention, and FIGS. 3(a) and 3(b) are sectional views showing the piezoelectric motor in use. Housing, 6...Driver, 6a.
...base, 6b...arm, 7...rotating body, 7a...bottomed tube, 8...first piezoelectric element,
9...Second piezoelectric element, 10...Spring. Patent applicant: NEC Corporation

Claims (1)

[Claims] a driving body rotatably provided within a bearing housing and having a base extending in the axial direction and an arm extending laterally of the base; and a driving body rotatably provided on the same axis as the driving body. a rotating body having a body portion facing each other, a first piezoelectric element capable of connecting the rotating body and the driving body is provided between the body portion and the base portion, and a first piezoelectric element capable of connecting the rotating body and the driving body is provided between the body portion and the base portion; A second piezoelectric element that expands and contracts with frequency is provided between the bearing housing and the arm, and the piezoelectric element applies rotational force to the drive body, and a spring applies a return force. piezoelectric motor.