Power transmitting mechanism and power transmitting method
AssigneeCanon Kabushiki Kaisha
InventorsKaishi Ohashi, Takashi Maeno, Kenjiro Takemura, Tatsuya Koyama
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Abstract
A mechanism for mechanically coupling a driving source and a driven member. The mechanism includes a first member coupled to the driving source and a second member coupled to the driven member. A resilient member exerts a force to bring the first and second members into pressure contact at a contact surface. A vibration is excited in the contact surface of the first member to produce a levitation force, based on an ultrasonic levitation, acting upon the second member. Frictional force between the first member and the second member is changed depending on the levitation force, thereby changing power transmitted between the first member and the second member.
Claims11
A driving device comprising:
- a first member coupled to a first structure;
- a second member coupled to a second structure, the second member including a piezoelectric device;
- a contactor exerting a contact force to bring said first member into contact with said second member;
- a driving source coupled to at least one of the first member via the first structure and the second member via the second structure, wherein the driving source drives at least one of the first structure and the second structure;
- an electrical signal source supplying an electrical signal to the piezoelectric device;
- and
- a control circuit coupled to the electrical signal source and controlling the electrical signal supplied to the piezoelectric device so as to generate a levitation force,
- wherein the control circuit controls the electrical signal so that a frictional force generated between the first member and the second member continuously changes by the levitation force.
A method of controlling mechanical coupling of first and second structures into contact, said method comprising the following steps:
- coupling the first structure to a first member having a surface;
- coupling the second structure to a second member including a piezo electric device;
- pressing said first and second members together at said surface with a contact force such that a frictional force is generated between said first and second members;
- supplying an electrical signal to the piezoelectric device;
- and
- controlling the electrical signal supplied to the piezoelectric device so as to generate a levitation force and so that the frictional force generated between the first and second members continuously changes by the levitation force.
Dependencies are inferred from the claim text.