A bidirectional rotating ultrasonic motor driven by a single electrical signal

Abstract

The invention discloses a two-way rotary ultrasonic motor driven by single electrical signals. The ultrasonic motor comprises two same stators, a rotor and a set of positive-voltage pre-tightening adjusting mechanisms, wherein each stator comprises a mandrel, as well as a rear cover plate, a piezoelectric ceramic slice, an electrode slice and an elliptical vibration mode converter which are sleeved on the mandrel sequentially; the rotor comprises a friction disc and a bearing; and each positive-voltage pre-tightening adjusting mechanism comprises a spring and a support structure. By utilizing an elliptical vibration mode converter structure in special design, based on the longitudinal vibration of the piezoelectric ceramic slice, the elliptical trajectory movement of mass points on the end surface of a stator driving tooth is achieved, so that the rotor is driven to perform continuous two-way rotating motion when the two stators work respectively. The ultrasonic motor disclosed by the invention has the advantages of being simple in structure, easy to manufacture, easy to microminiaturize and integrate, low in cost, small in control difficulty and the like, thereby being broad 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 ...

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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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