| 摘要 |
PURPOSE:To rotate an output shaft freely by hand by a method wherein an oscillator is provided with an instantaneously invertible signal to release the biting condition of mutual recessed and projected cam surfaces of first and second cams. CONSTITUTION:An ultrasonic motor rotates a cylindrical cam 10 by supplying a travelling wave generating signal to an oscillator 8 from a driving circuit to generate a travelling wave in a stator 6. A cylindrical cam 22, engaging with the cylindrical cam 10, is pushed by recessed and projected cam surfaces 14, 26 along an output shaft 4 and is rotated while abutting a friction member 28 against a rotor 18 with a pressure. Upon stopping the rotation, an instantaneous invertible signal is given from the driving circuit to the oscillator 8 to release the biting condition between said recessed and projected cam surfaces 14, 26. As a result, the cylindrical cam 22 becomes free of sliding movement along the output shaft 4 whereby the title motor is brought into a condition capable of being rotated by an external operating force. |
