Displacement member, driving member, actuator, and driving device

Patent metadata

Field	Value
Publication number	US-9455394-B2
Application number	US-201313948510-A
Country	US
Kind code	B2
Filing date	Jul 23, 2013
Priority date	Feb 7, 2011
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A displacement member with a driving element that includes first and second side surfaces that extend in a first direction and top and bottom surfaces that extend in a second direction perpendicular to the first direction. The driving element is a piezoelectric element that expands and contracts in the second direction when a pulsed voltage is applied. Further, an elastic conversion element is provided that contains the driving element and includes a first portion that is disposed adjacent the top surface of the driving element and that includes a displacement portion that is displaced downwardly and upwardly in the first direction when the driving element expands and contracts in the second direction, respectively.

First claim

The invention claimed is:

1. A displacement member comprising:
a driving element including first and second side surfaces extending in a first direction and top and bottom surfaces extending in a second direction perpendicular to the first direction, the driving element being configured to expand and contract in the second direction in response to a pulsed voltage; and
an elastic conversion element containing the driving element and including;
a first portion disposed above the top surface of the driving element and including a convex portion that is spaced apart from the top surface of the driving element,
a second portion coupled to one end of the first portion and contacting the first side surface of the driving element, and
a third portion coupled to a second end of the first portion directly and contacting the second side surface of the driving element,

wherein the first portion of the elastic conversion element comprises a displacement portion that moves downwardly and upwardly in the first direction when the driving element expands and contracts in the second direction, respectively.

2. The displacement member according to claim 1 ,
wherein the elastic conversion element further comprises:
a fourth portion extending perpendicularly to the second portion and fixed to at least a first portion of the bottom surface of the driving element, and
a fifth portion extending perpendicularly to the third portion and fixed to at least a second portion of the bottom surface of the driving element.

3. The displacement member according to claim 2 , wherein the fourth portion is directly coupled to the fifth portion and substantially all of the bottom surface of the driving element is fixed to the fourth and fifth portions.

4. The displacement member according to claim 3 , wherein the fourth portion and the fifth portion of the elastic conversion element are integrally formed.

5. The displacement member according to claim 2 , further comprising a resin adhesive layer configured to fix the fourth and fifth portions of the elastic conversion element to the first and second portions of the bottom surface of the driving element, respectively.

6. The displacement member according to claim 2 , wherein the second portion is fixed to the first side surface of the driving element and the third portion is fixed to the second side surface of the driving element.

7. The displacement member according to claim 2 , wherein the conversion element further comprises:
a sixth portion that couples the second portion to the fourth portion and is disposed above an end edge portion of the bottom surface adjacent the first side surface,
a seventh portion that couples the third portion to the fifth portion and is disposed above an end edge portion of the bottom surface adjacent the second side surface, and
wherein each of the sixth and seventh portions is spaced apart from the bottom surface of the driving element.

8. The displacement member according to claim 1 , wherein the driving element is fitted into the elastic conversion element.

9. The displacement member according to claim 1 , wherein the conversion element comprises a metal.

10. The displacement member according to claim 1 , wherein the driving element comprises a piezoelectric element having a plurality of first and second electrodes.

11. The displacement member according to claim 2 ,
wherein the displacement portion of the first portion of the elastic conversion element extends in the second direction, and
wherein the first portion of the elastic conversion element further comprises first and second planar side surfaces that extend from opposite ends of the displacement portion to the second and third portions of the elastic conversion element, respectively.

12. The displacement member according to claim 11 , wherein the first and second planar side surfaces each extend from the displacement portion at an angle between 15 degrees and 45 degrees.

13. The displacement member according to claim 11 ,
wherein the top and bottom surfaces of the driving element are disposed a first distance L 1 from each other,
wherein the first and second side surfaces of the driving element are disposed a second distance L 2 from each other, and
wherein the ratio of L 2 to L 1 is between 0.8 and 2.0.

14. The displacement member according to claim 13 ,
wherein the displacement portion of the first portion of the elastic conversion element extends a third distance L 3 , and
wherein the ratio of L 3 to L 2 is between 0.3 and 0.7.

15. An actuator comprising:
a displacement member including:
a driving element including first and second side surfaces extending in a first direction and top and bottom surfaces extending in a second direction perpendicular to the first direction, the driving element being configured to expand and contract in the second direction in response to a pulsed voltage; and
an elastic conversion element containing the driving element and including:
a first portion disposed above the top surface of the driving element,
a second portion coupled to one end of the first portion and contacting the first side surface of the driving element, and
a third portion coupled to a second end of the first portion and contacting the second side surface of the driving element,

wherein the first portion of the elastic conversion element comprises a displacement portion that move downwardly and upwardly in the first direction when the driving element expands and contracts in the second direction, respectively; and

a displaced member attached to the displacement member.

16. The actuator according to claim 15 , wherein the elastic conversion element further comprises:
a fourth portion extending perpendicularly to the second portion and fixed to at least a first portion of the bottom surface of the driving element, and
a fifth portion extending perpendicularly to the third portion and fixed to at least a second portion of the bottom surface of the driving element, and
wherein the displaced member is attached to at least one of the first portion, the fourth portion and the fifth portion of the elastic conversion element.

17. The actuator according to claim 15 , wherein the displaced member is attached to the displacement portion.

18. The actuator according to claim 15 ,
wherein the displaced member is a shaft, and
wherein the actuator further comprises a driven member coupled to the shaft that is configured to move in the first direction based on a frictional force with the shaft when the shaft is displaced in the first direction.

19. A driving device comprising:
the actuator according to claim 15 ; and
a control unit configured to control the actuator.

Assignees

• Murata Manufacturing Co

Inventors

• Inoue Jiro

Classifications

• H02N2/001

  Driving devices, e.g. vibrators · CPC title

• H02N2/025 Primary

  Inertial sliding motors · CPC title

• H02N2/043

  Mechanical transmission means, e.g. for stroke amplification · CPC title

• H01L41/042 Primary

  Electricity · mapped topic

• H02N2/04 Primary

  Constructional details · CPC title