Piezoelectric driving device, motor, robot, and pump

Patent metadata

Field	Value
Publication number	US-10601345-B2
Application number	US-201615367553-A
Country	US
Kind code	B2
Filing date	Dec 2, 2016
Priority date	Dec 3, 2015
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A piezoelectric driving device includes: a substrate including a fixed portion, and a vibrating body portion which is provided with a piezoelectric element and is supported by the fixed portion; and a contact portion which comes into contact with a driven body, and transmits movement of the vibrating body portion to the driven body, the contact portion is provided at an end portion in the longitudinal direction of the vibrating body portion, and a difference between a distance between the end portion when the contact portion is not pressed against the driven body and a tip end of the contact portion, and a distance between the end portion when the contact portion is pressed against the driven body and the tip end, is smaller than a total amplitude in the longitudinal direction in a case where the vibrating body portion is driven.

First claim

What is claimed is:

1. A piezoelectric driving device comprising: a substrate including a fixed portion, and a vibrating body portion which is provided with a piezoelectric element and is supported by the fixed portion; and a contact portion which comes into contact with a driven body, and transmits movement of the vibrating body portion to the driven body, wherein the contact portion is provided at an end portion in the a longitudinal direction of the vibrating body portion, and wherein a difference between a distance between the end portion when the contact portion is not pressed against the driven body and a tip end of the contact portion, and a distance between the end portion when the contact portion is pressed against the driven body and the tip end, is smaller than a total amplitude in the a longitudinal direction in a case where the vibrating body portion is driven, wherein the contact portion includes a tip end portion which is configured of the tip end, and an adhesive portion, which is provided between the tip end portion and the vibrating body portion, and wherein, when a length in a longitudinal direction of the tip end portion is Ls, a length in a width direction orthogonal to a longitudinal direction of a contact surface between the tip end portion and the adhesive portion is Ws, a length in the direction orthogonal to a longitudinal direction and the width direction of the contact surface is Ts, Young's modulus of the tip end portion is Es, and a Young's modulus of the adhesive portion is Ea, the total amplitude is Xo and a pushing force of the driven body on the contact portion is Fo, a length La in a longitudinal direction of the adhesive portion satisfies a relationship of La<(Xo/Fo)×Ea×Ws×Ts−(Ls×Ea)/Es.

2. The piezoelectric driving device according to claim 1 , wherein, when the total amplitude is Xo and the pushing force of the driven body on the contact portion is Fo, a spring constant K in the a longitudinal direction of the contact portion satisfies a relationship of K>Fo/Xo.

3. A motor comprising:
the piezoelectric driving device according to claim 1 ; and
a rotor which is rotated by the piezoelectric driving device.

4. A motor comprising:
the piezoelectric driving device according to claim 2 ; and
a rotor which is rotated by the piezoelectric driving device.

5. A robot comprising:
a plurality of ring portions;
a joint which connects the plurality of ring portions to each other; and
the piezoelectric driving device according to claim 1 which rotates the plurality of ring portions by the joint.

6. A robot comprising:
a plurality of ring portions;
a joint which connects the plurality of ring portions to each other; and
the piezoelectric driving device according to claim 2 which rotates the plurality of ring portions by the joint.

7. A pump comprising:
the piezoelectric driving device according to claim 1 ;
a tube which transports liquid; and
a plurality of fingers which close the tube by driving of the piezoelectric driving device.

8. A pump comprising:
the piezoelectric driving device according to claim 2 ;
a tube which transports liquid; and
a plurality of fingers which close the tube by driving of the piezoelectric driving device.

Assignees

• Seiko Epson Corp

Inventors

• Takahashi Tomoaki
• Arakawa Yutaka

Classifications

• F04B43/095

  Piezoelectric drive · CPC title

• F04B17/003

  driven by piezoelectric means (F04B43/046 and F04B43/095 take precedence) · CPC title

• F04B23/02

  having reservoirs · CPC title

• F04B43/08

  having tubular flexible members (F04B43/12 takes precedence) · CPC title

• H02N2/004

  Rectangular vibrators · CPC title