Piezoelectric motor and a disk drive using same

摘要

A piezoelectric motor of a linear contact type contains one or more actuators placed about a rotor. Each actuator contains at least one piezoelectric vibrator with a working end urged against the rotor. Periodic oscillations of each vibrator cause compressions of the rotor not exceeding its natural elastic compression limit so after its compression the rotor fully restores its initial cylindrical shape. Such elastic compressions ensure longer operational life of the motor. In another embodiment, each actuator has a laminated design with at least two vibrators separated by an isolator. The isolator extends beyond the vibrators and has appropriate hardness to engage with the rotor. A rotor of laminated design is also described to achieve the optimum hardness relative to the hardness of the actuators. The hardness of the vibrator is about 5x107 N/cm2 and much higher than the hardness of the rotor being about 2x106 N/cm2. A disk drive is described as one of the most advantageous applications of the motor of the invention to drive optical and magnetic disks such as in a CD-ROM drive etc.