| 摘要 |
PURPOSE:To make an output torque variable and reduce an idling torque, by a method wherein either one of a holding member and an output member is provided with an electromagnetic member while both of the holding and output members are attracted by a magnetic force to adjust the abutting pressure between both members. CONSTITUTION:An ultrasonic motor consists of an ultrasonic oscillator 1, a holding member or a yoke 2, an output member 3, an elastic body 4 and an electromagnetic member 5. The output member 3 is formed by a disc type rotor 30, a central hole 31a, bored at the center of the rotor 3, and a pinion 31 having outer peripheral teeth 31b. The electromagnetic member 5 consists of a magnetic core 50, attached to a shaft 50a, and an electromagnetic coil 51, mounted on the magnetic core, while the eleotromagnetic member 5 is attached to the yoke 2. According to this method, an abutting pressure (pushing force) between the output member 3 and the elastic body 4 may be varied by the magnitude of a magnetic force generated in the electromagnetic member 5, therefore, the output torque of the output member 3 may be controlled. |
