Ultrasonic motor
0301221-210
[DEFINITION]
A motor that uses ultrasonic vibration transmitted through the
elastic mechanical members.
[DESCRIPTION]
An ultrasonic motor stator is pressed to a rotor to transform
ultrasonic vibration to mechanical output motion. Ultrasonic motors have the following
characteristics: 1) a simple structure assisting miniaturization and light weight, 2) direct drive
capability with high torque in the low-speed range, 3) a high power-to-weight ratio, 4) quick
response, 5) good controllability, 6) the ability to maintain the rotor position because of a
self-holding force when the power supply is off, and 7) no magnetic noise. On the other hand,
problems include the friction and wear that occur between the stator and the rotor. Ultrasonic
motors can be driven by standing wave or progressive wave. The former offers high energy conversion
efficiency, while the latter gives excellent controllability because forward and reverse rotations
are possible. Generally, ultrasonic motors are used in direct drive applications requiring low
speed and high torque performance.
[References]
(4)(6)(8)(14)(15)
[Related Terms]
Piezoelectric linear actuator, Piezoelectric element