Vibration wave motor and driving apparatus using the vibration wave motor

Patent metadata

Field	Value
Publication number	US-10171008-B2
Application number	US-201514884190-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 27, 2014
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A vibration wave motor includes a vibrating plate having a rectangular surface; a piezoelectric device bonded to the vibrating plate, and configured to vibrate at high frequency; and a projection provided on the vibrating plate or the piezoelectric device. In the vibration wave motor, a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of torsional vibration in a natural vibration mode under a state in which the vibrating plate, the piezoelectric device, and the projection are integrated, is a natural vibration mode of bending vibration in a direction parallel to or orthogonal to a torsion center axis of the torsional vibration in the natural vibration mode. The projection is provided at a position closer to an antinode than to a node, which are in the direction orthogonal to the torsion center axis of the torsional vibration in the natural vibration mode.

First claim

What is claimed is:

1. A vibration wave motor, comprising:
a vibrating plate having a rectangular surface;
a piezoelectric device bonded onto the vibrating plate, and configured to vibrate at high frequency; and
a projection provided on one of the vibrating plate and the piezoelectric device, wherein
a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of torsional vibration in a natural vibration mode under a state in which the vibrating plate, the piezoelectric device, and the projection are integrated, is a natural vibration mode of bending vibration in one of a direction parallel to and a direction orthogonal to a torsion center axis of the torsional vibration in the natural vibration mode, and
the projection is provided at a position closer to an antinode than to a node, the node and the antinode being in the direction orthogonal to the torsion center axis of the torsional vibration in the natural vibration mode.

2. A vibration wave motor according to claim 1 , wherein
at least two projections are provided, and
an arbitrary two of the projections are prevented from sandwiching the node in the direction orthogonal to the torsion center axis of the torsional vibration in the natural vibration mode or sandwich an even number of the nodes.

3. A vibration wave motor according to claim 1 , wherein the natural vibration mode of the torsional vibration is a secondary natural vibration mode of the torsional vibration.

4. A vibration wave motor according to claim 1 , wherein the natural vibration mode of the bending vibration is a primary natural vibration mode of the bending vibration.

5. A vibration wave motor according to claim 1 , wherein
a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of the torsional vibration in a secondary natural vibration mode, is a primary natural vibration mode of bending vibration in a direction orthogonal to a torsion center axis of the torsional vibration in the secondary natural vibration mode, and
the projection is provided at a position closer to an antinode than to a node of the bending vibration in the primary natural vibration mode.

6. A vibration wave motor according to claim 1 , wherein
a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of the torsional vibration in a secondary natural vibration mode, is a primary natural vibration mode of bending vibration in a direction orthogonal to a torsion center axis of the torsional vibration in the secondary natural vibration mode; and
the projection is provided at a position closer to a node than to an antinode of the bending vibration in the primary natural vibration mode.

7. A vibration wave motor according to claim 1 , wherein
a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of the torsional vibration in a secondary natural vibration mode, is a primary natural vibration mode of bending vibration in a direction parallel to a torsion center axis of the torsional vibration in the secondary natural vibration mode; and
the projection is provided at a position closer to an antinode than to a node of the bending vibration in the primary natural vibration mode.

8. A vibration wave motor according to claim 1 , wherein the projection is provided on the rectangular surface of the vibrating plate.

9. A vibration wave motor according to claim 1 , further comprising a coupling portion to be directly or indirectly coupled to a holding member configured to hold a vibrator moving in synchronization with the vibrating plate, the coupling portion being provided at a side orthogonal to the torsion center axis of the rectangular surface of the vibrating plate.

10. A vibration wave motor according to claim 1 , further comprising a coupling portion to be directly or indirectly coupled to a holding member configured to hold a vibrator moving in synchronization with the vibrating plate, the coupling portion being provided at a side parallel to the torsion center axis of the rectangular surface of the vibrating plate.

11. A vibration wave motor according to claim 1 , wherein the vibrating plate includes a portion that is prevented from being covered with the piezoelectric device.

12. A vibration wave motor according to claim 9 , wherein the coupling portion to be directly or indirectly coupled to the holding member moving in synchronization with the vibrating plate is provided at a portion that is prevented from being covered with the piezoelectric device.

13. A vibration wave motor according to claim 1 , further comprising a friction member held in contact with the vibrating plate, to which the vibrating plate moves relatively due to the high-frequency vibration of the vibrating plate,
wherein the vibrating plate is configured to move relative to the friction member in a direction orthogonal to the torsion center axis of the rectangular surface of the vibrating plate.

14. A vibration wave motor according to claim 1 , further comprising a friction member configured to move along the fixed vibrating plate.

15. A vibration wave motor according to claim 1 , wherein the vibration wave motor comprises an ultrasonic motor in which the vibrating plate vibrates at an ultrasonic frequency.

16. A driving apparatus, comprising a vibration wave motor,
the vibration wave motor comprising:
a vibrating plate having a rectangular surface;
a piezoelectric device bonded to the vibrating plate, and configured to vibrate at high frequency;
a projection provided on one of the vibrating plate and the piezoelectric device, wherein

a natural vibration mode, which has a resonant frequency equal to or adjacent to a resonant frequency of torsional vibration in a natural vibration mode under a state in which the vibrating plate, the piezoelectric device, and the projection are integrated, is a natural vibration mode of bending vibration in one of a direction parallel to and a direction orthogonal to a torsion center axis of the torsional vibration in the natural vibration mode,
the projection is provided at a position closer to an antinode than to a node, the node and the antinode being in the direction orthogonal to the torsion center axis of the torsional vibration in the natural vibration mode, and
the direction orthogonal to the torsion center axis of the rectangular surface of the vibrating plate is used as a driving direction.

17. A driving apparatus according to claim 16 , wherein the vibration wave motor comprises an ultrasonic motor in which the vibrating plate vibrates at an ultrasonic frequency.

Assignees

• Canon Kk

Inventors

• Nishitani Hitoshi
• Ninomiya Shunsuke

Classifications

• H02N2/001 Primary

  Driving devices, e.g. vibrators · CPC title

• H02N2/026

  by pressing one or more vibrators against the driven body · CPC title

• H02N2/0015 Primary

  using only bending modes · CPC title