Bidirectional Rotary Ultrasonic Motor Driven by Single Electric Signal

Abstract

The invention discloses a single-electric-signal driving bidirectional rotating ultrasonic motor. The single-electric-signal driving bidirectional rotating ultrasonic motor comprises two same stators, a rotor and a set of positive-pressure prestressing force adjusting mechanism. Each stator comprises a mandrel, a rear cover plate, a piezoelectric ceramic piece, an electrode plate and an elliptic vibration mode converter, wherein the mandrel is sequentially sleeved with the rear cover plate, the piezoelectric ceramic piece, the electrode plate and the elliptical vibration mode converter. The rotor comprises a friction plate and a bearing. The positive-pressure prestressing force adjusting mechanism comprises a spring and a supporting structure. Through the structure of the elliptic vibration mode converter with the special design, the elliptic track motion of mass points on a driving tooth end face of each stator is achieved through longitudinal vibration of the piezoelectric ceramic pieces, and the rotor is driven by one of the stators to continuously rotate when the two stators work individually. The single-electric-signal driving bidirectional rotating ultrasonic motor has the advantages of being simple in structure, easy to manufacture, prone to microminiaturization and integration, low in cost, low in control difficulty and wide in application prospect.

Description

technical field [0001] The invention relates to the field of ultrasonic motors utilizing the inverse piezoelectric effect of piezoelectric ceramics, in particular to a bidirectional rotating ultrasonic motor driven by a single electric signal. Background technique [0002] The rotary ultrasonic motor is a new type of micro-motor developed and applied rapidly in the 1980s. It is an electromechanical coupling device that uses the inverse piezoelectric effect of piezoelectric materials to convert electrical energy to mechanical energy. Through the friction between the stator and the rotor, the The micro-vibration of the elastomer is converted into the macro-rotational motion of the rotor, which directly drives the load. In the existing rotary ultrasonic motors, there are generally problems such as small driving torque, large axial volume, large wear difference between the inner and outer diameter contact areas of the stator and rotor, and low working reliability. [0003] The ...

AI Technical Summary

Problems solved by technology

Although the motor has the advantages of large output torque, etc., its structure is complicated, and the screw movement (rotation force) of the compression nut during the compression process of the piezoelectric ceramic sheets is very easy to cause misalignment between the piezoelectric ceramic sheets, which is difficult to achieve. The technical requirement to ensure a 60-degree misalignment between adjacent piezoelectric ceramic sheets; in addition, there is no positioning device between the stator and the rotor of the motor, which affects the accuracy of the contact position between the stator and the rotor, thereby affecting the motor. Stability of torque and speed; this type of rotating ultrasonic motor has complex structure, difficult manufacturing and installation, high cost, poor stability of motor torque and speed, etc.

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