Vibration wave motor

• US 20060267416A1
• Filed: 04/25/2006
• Published: 11/30/2006
• Est. Priority Date: 05/31/2005
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Suzuki, Masaharu
• Granted Patent: US 7,425,770 B2
• Time in Patent Office: Days
• US Class Current: 310/323.30
• CPC Class Codes: H02N 2/163 Motors with ring stator

Abstract

Provided is a vibration wave motor including a pressurizing mechanism and a guide mechanism which are used for a moving member and can be thinned. The influence of a restoring force can be eliminated. The vibration wave motor includes an elastic vibration member which is composed of a permanent magnet and a piezoelectric element which are fixed to each other, a plurality of motion extraction portions provided on the permanent magnet, and a moving member which is pressurized to be in contact with the plurality of motion extraction portions. A closed magnetic circuit of a magnetic flux is formed to connect between the elastic vibration member and the moving member through the plurality of motion extraction portions. A flow direction of the magnetic flux passing through the moving member is aligned with a moving direction of the moving member.

Claims

1. A vibration wave motor, comprising:

an elastic vibration member including a permanent magnet and an electro-mechanical energy conversion element which are fixed to each other;

a plurality of motion extraction portions provided on the elastic vibration member; and

a moving member pressurized to the plurality of motion extraction portions into contact therewith,

wherein;

a closed magnetic circuit of a magnetic flux is formed to connect between the elastic vibration member and the moving member through the plurality of motion extraction portions; and

a flow direction of the magnetic flux passing through the moving member is aligned with a moving direction of the moving member.

2. A vibration wave motor according to claim 1, wherein the elastic vibration member generates vibrations corresponding to a plurality of vibration modes to spheroidally move the plurality of motion extraction portions by synthesization of the vibrations.

3. A vibration wave motor according to claim 1, wherein contact widths between the moving member and the plurality of motion extraction portions in a direction orthogonal to the moving direction of the moving member are equal to each other to form a magnetic circuit in which the magnetic flux concentratedly flows through the moving member and the plurality of motion extraction portions.

4. A vibration wave motor according to claim 1, wherein the plurality of motion extraction portions are magnetized to alternately reverse poles.

5. A vibration wave motor according to claim 1, wherein:

the moving member is made of a grain-oriented magnetic steel sheet; and

the moving direction of the moving member is aligned with a direction of axis of easy magnetization to perform linear driving.

6. A vibration wave motor according to claim 1, wherein:

the moving member is made of a non-oriented magnetic steel sheet;

each of the moving member and the elastic vibration member is formed in a disk shape; and

the moving member is rotated by the elastic vibration member.

7. A vibration wave motor according to claim 1, wherein:

the permanent magnet included in the elastic vibration member is subjected to one-sided two-pole magnetization; and

the plurality of motion extraction portions are fixed to the permanent magnet corresponding to poles thereof.

8. A vibration wave motor according to claim 1, further comprising:

a soft magnetic member located between the permanent magnet included in the elastic vibration member and the electro-mechanical energy conversion element;

the permanent magnet subjected to two-pole magnetization in a thickness direction; and

a closed magnetic circuit of a magnetic flux which is formed to connect between the soft magnetic member and the moving member through the plurality of motion extraction portions and the permanent magnet.