Electrostatic force-driven miniature ultrasonic motor

Abstract

The invention discloses an electrostatic force-driven miniature ultrasonic motor. The electrostatic force-driven miniature ultrasonic motor includes silicon-based stator, a rotor, a bearing and an elastic pre-pressure device, and an upper surface of the silicon-based stator is provided with a tooth-shaped protrusion; one end of the rotor sleeves in the bearing to perform rotational motion, and the stator is in contact with the tooth-shaped protrusion of the silicon-based stator; and the elastic pre-pressure device applies pre-pressure to the rotor along an axial direction, so that normal pressure is generated between the rotor and the silicon-based stator, the silicon-based stator generates ultrasonic vibration under the function of driving voltage, and the tooth-shaped protrusion of the silicon-based stator drives the rotor to rotate through frictional force. The electrostatic force-driven miniature ultrasonic motor provided by the invention satisfies the characteristics of small size, simple structure, mature materials and preparation technology and the like.

Description

technical field [0001] The invention belongs to the technical field of ultrasonic motors, in particular to a micro-ultrasonic motor based on electrostatic force excitation of ultrasonic vibration of a structure. Background technique [0002] Compared with conventional electromagnetic motors, especially in the small size (mm-cm) range, ultrasonic motors have shown many unique advantages, such as relatively high power density, large driving force, and relatively high efficiency. Traditional electromagnetic motors have become difficult to manufacture in the order of several millimeters, and its efficiency is only a few percent (<8%) at several millimeters, because it lacks a strong enough magnetic field . The ultrasonic motor uses the ultrasonic vibration of the structure (stator) and the interface friction to drive the movement of the rotor (mover), and its efficiency is basically independent of the size, and there is no magnetic field problem. Ultrasonic motors maintain ...

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Problems solved by technology

Although the above research work demonstrates the micro-ultrasonic motor based on PZT / Si composite diaphragm, it is difficult to obtain high-quality PZT piezoelectric film (the preparation process of PZT film requires high-temperature heat treatment in an oxygen-containing atmosphere, which is different from the silicon semiconductor process. Incompatibility, and PZT is difficult to control the performance and consistency of the film due to the complex composition and the volatility of the lead element. In addition, the etching process of the PZT film is also to be studied), and the performance and consistency of the ultrasonic motor are difficult to guarantee

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