Electrical generator or motor structure – Non-dynamoelectric – Piezoelectric elements and devices
Reexamination Certificate
1999-06-02
2001-03-06
Mullins, Burton (Department: 2834)
Electrical generator or motor structure
Non-dynamoelectric
Piezoelectric elements and devices
C310S323040, C310S323050, C310S323080, C310S323090
Reexamination Certificate
active
06198201
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vibration wave motor or a vibration wave apparatus for driving a driven member with a vibration wave motor as a driving source.
2. Related Background Art
As a vibration wave apparatus, there has heretofore been put into practical use a travelling wave type vibration wave motor utilizing flexural vibration generated on an elastic member made of a metal or the like formed, for example, into a ring-like shape or the like, or a bar-like vibration wave motor utilizing the flexural vibration of a vibration member formed into a bar-like shape.
On the other hand, the technique of connecting a plurality of vibration wave motors together to make output torque great has also been proposed (Japanese Patent Application Laid-open No. 9-37573).
Now, a vibration wave motor has as a basic construction a vibration member in which driving vibration is generated, and a contacting member which is provided in press contact with the vibration member. When, for example, the vibration member is a stator, it becomes necessary in utilizing the vibration wave motor as a driving source to fix the vibration member to a fixed member such as a motor case by some method.
For example, in the case of a ring-like vibration wave motor, a ring-like vibration member as a stator is not fixed to a motor case in the outer peripheral portion thereof, and the meshing engagement between a projection formed on the outer diametrical portion of the stator and a groove formed in the inner side of the case provides a rotation stopping mechanism. It utilizes a so-called spline mechanism.
Therefore, the stator is freely movable in a gap formed in the meshing portion between the projection and the groove which constitutes spline coupling and, as a result, there has been a case where backlash occurs there.
Therefore, even if an attempt was made to accurately control the rotation of the contacting member as a rotor, the rotor could not be controlled with accuracy equal to or less than the error due to backlash in movement of the stator/vibration member.
Also, when the outer diametrical portion of the stator and the motor case are fixed, it is conceivable that of vibration in the stator will propagate to the motor case, energy loss will be increased, and the driving efficiency of the motor will deteriorate or the vibration which propagates to the motor case may adversely affect a sensor such as an encoder and surrounding instruments in the form of noise.
Also, there has heretofore been put into practical use as a vibration wave apparatus a travelling wave type vibration wave motor in which an electromechanical energy conversion element, such as a piezoelectric element, adhesively secured to an elastic member made of a metal formed, for example, into a ring-like shape or the like is used as a vibration member and which utilizes flexural vibration excited in the vibration member by a driving signal, such as an alternating signal, being applied to the piezoelectric element, or a bar-like vibration wave motor utilizing the flexural vibration of a vibration member formed into a bar-like shape.
As a system for supporting and fixing the vibration member in the ring-like travelling wave type vibration wave motor, there has been proposed structure in which the vibration member is supported on felt disposed in a motor case to thereby prevent the propagation of vibration to a fixed portion for fixing the vibration member to the case, or structure in which a vibration member itself is made into a ring-like shape and a fixed portion disposed inside it and the vibration member are connected together by a thin plate (sometimes the vibration member and the thin plate and further the fixed portion are made as a unit) to thereby prevent the propagation of vibration to the fixed portion.
On the other hand, with respect to the supporting and fixing features of the vibration member in the bar-like vibration wave motor, there has been proposed structure in which a thin bar (pin) is used coaxially with the bar-like vibration member to connect the vibration member and a fixed portion together and thereby prevent the propagation of vibration to the fixed portion.
SUMMARY OF THE INVENTION
One aspect of the invention is a vibration wave apparatus having a group of vibration members comprising a plurality of vibration members provided with driving portions in which driving waves are formed on the axially opposite sides, the vibration members being disposed coaxially with one another, a plurality of contacting members and a holding member for holding the group of vibration members, the plurality of vibration members and the plurality of contacting members being moved relative to each other in the same direction, and the durability of the apparatus can be improved.
One aspect of the invention is a vibration wave apparatus in which an electro-mechanical energy conversion element is sandwiched between a first elastic member and a second elastic member and a plate-like supporting member is provided at a symmetrical plane position axially intermediate of the first elastic member and the second elastic member, and the propagation of vibration to the supporting member can be minimized.
REFERENCES:
patent: 4580073 (1986-04-01), Okumura et al.
patent: 4587452 (1986-05-01), Okumura et al.
patent: 4678956 (1987-07-01), Izukawa et al.
patent: 4692650 (1987-09-01), Okumura et al.
patent: 4692651 (1987-09-01), Hiramatsu et al.
patent: 4734610 (1988-03-01), Okumuar et al.
patent: 4752711 (1988-06-01), Tsukimoto et al.
patent: 4763148 (1988-08-01), Tsukimoto et al.
patent: 4771203 (1988-09-01), Mukohjima et al.
patent: 4788468 (1988-11-01), Izukawa et al.
patent: 4810923 (1989-03-01), Tsukimoto et al.
patent: 4937488 (1990-06-01), Fujie et al.
patent: 5017823 (1991-05-01), Okumura
patent: 5032754 (1991-07-01), Iwao et al.
patent: 5099166 (1992-03-01), Hirano et al.
patent: 5172023 (1992-12-01), Kawai et al.
patent: 5300850 (1994-04-01), Okumura et al.
patent: 5554905 (1996-09-01), Gschwind et al.
patent: 5585685 (1996-12-01), Maeno et al.
patent: 5760529 (1998-06-01), Tamai et al.
patent: 5814919 (1998-09-01), Okumura et al.
patent: 5917270 (1999-06-01), Tsukimoto et al.
patent: 5949178 (1999-09-01), Tamai et al.
patent: 5952766 (1999-09-01), Mukohjima et al.
patent: 6-120580 (1994-04-01), None
patent: 9-37573 (1997-02-01), None
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Mullins Burton
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