Ultrasonic motor and method of adjusting the same
AssigneeNEC Corporation
InventorsOsamu Ohnishi, Sadayuki Takahashi, Osamu Myohga, Tadao Uchikawa, Takeshi Inoue, Isao Kagaya, Sadayuki Ueha
Life of this patent
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Abstract
An ultrasonic motor has a longitudinal-torsional composite transducer, a stator constituted by an ultrasonic vibrator sandwiching the transducer, and a rotor urged against the stator. The stator excites longitudinal-torsional ultrasonic vibrations to rotate the rotor by a frictional force. The motor includes a vibration adjusting rod for matching resonance frequencies of longitudinal and torsional ultrasonic vibrations of the stator with each other.
Claims17
An ultrasonic motor comprising:
- a longitudinal-torsional composite transducer;
- a stator including an ultrasonic vibrator sandwiching said transducer;
- a rotor urged against said stator for causing said stator to excite longitudinal-torsional ultrasonic vibrations and for rotating said rotor by a frictional force;
- and
- adjusting means for matching resonance frequencies of longitudinal and torsional ultrasonic vibrations of said stator with each other;
- wherein said adjusting means comprises pressure adjusting means for adjusting the pressure of urging said rotor against said stator.
A method of adjusting an ultrasonic motor having a longitudinal-torsional composite transducer, a stator including an ultrasonic vibrator sandwiching the transducer, and a rotor urged against the stator for causing the stator to excite longitudinal-torsional ultrasonic vibrations and rotating the rotor by a frictional force comprising:
- matching resonance frequencies of longitudinal and torsional ultrasonic vibrations of said stator with each other by arranging pressure adjusting means for adjusting a pressure for urging the rotor against the stator and matching the resonance frequencies of longitudinal and torsional ultrasonic vibrations by adjusting the pressure adjusting means.
A method of adjusting an ultrasonic motor having a longitudinal-torsional composite transducer, a stator including an ultrasonic vibrator sandwiching the transducer, and a rotor urged against the stator for causing the stator to excite longitudinal-torsional ultrasonic vibrations and rotating the rotor by a frictional force comprising:
- matching resonance frequencies of longitudinal and torsional ultrasonic vibrations of said stator with each other;
- inserting a plate member for adjusting a frequency between the stator and the rotor;
- and
- matching the resonance frequencies of longitudinal and torsional ultrasonic vibrations by changing rigidity of the plate member.
A method according to claim 18 further comprising:
- arranging vibration adjusting means for matching a resonance frequency of axial vibrations as composite vibrations of longitudinal ultrasonic vibrations of the stator and flex vibrations of the ultrasonic vibrator with that of torsional ultrasonic vibrations, and
- matching the resonance frequency of axial vibrations as composite vibrations of longitudinal ultrasonic vibrations of the stator and flex vibrations of the ultrasonic vibrator with that of torsional ultrasonic vibrations by adjusting a notched portion of the vibration adjusting means.
Dependencies are inferred from the claim text.