A linear piezoelectric motor and its driving method

Abstract

The invention discloses a linear piezoelectric motor. The linear piezoelectric motor comprises a rotor, a fixed block and a stator, the stator comprises a contact lever, a micrometric displacement amplification mechanism and a first piezoelectric stack, a first end of the contact lever is in friction contact with a rotor sliding block in the rotor and pushes the rotor sliding block to perform linear motion, a second end of the contact lever is in surface contact with the first piezoelectric stack, the other end of the first piezoelectric stack is fixed, a third end of the contact lever is fixedly connected with the fixed block, a fourth end of the contact lever contacts with a driving foot of the micrometric displacement amplification mechanism, and the micrometric displacement amplification mechanism is a piezoelectric driving mechanism; the first piezoelectric stack applies a normal preloading force on the rotor sliding block through the contact lever, and the micrometric displacement amplification mechanism applies a tangential force on the rotor sliding block of through the contact lever. According to the linear piezoelectric motor provided by the invention, output voltage of the piezoelectric stack is taken as a power source, and based on a non-resonant mode, the power source pushes motion of the rotor sliding block through displacement amplification output of the contactlever, and the linear piezoelectric motor has the advantages of simple and compact structure, excellent control performance, high motor movement precision, high motor reliability and wide applicationrange.

Description

Technical field [0001] The invention relates to the research field of piezoelectric motors, in particular to a linear piezoelectric motor and a driving method thereof. Background technique [0002] Ultrasonic motor is a new type of micro special motor that was developed in the 1980s. With the rapid development of precision machining, robots, optical instruments, and MEMS operations, research on ultrasonic motors has become more and more demanding. Ultrasonic motors have self-locking, fast response and high position resolution, which provide innate good conditions for precise positioning control. [0003] Linear ultrasonic motor is a classification of ultrasonic motor according to the movement of the mover. It has the characteristics of large thrust-to-weight ratio, fast response, low speed and large torque, good control performance, and self-locking when power off. It is used in the fields of robots, precision instruments, medical equipment, etc. It is widely used and can directl...

AI Technical Summary

Problems solved by technology

The stator of the traditional resonant piezoelectric linear motor generally works in the resonance state, and the amplitude of the driving foot is amplified by resonance, and the excitation signal amplitude, frequency, and phase difference applied to the piezoelectric material have certain strict requirements. When changing, it is also necessary to properly adjust the frequency of the excitation signal of the piezoelectric material to maintain the stability of the motor output performance, so the design circuit of the ultrasonic motor driver is more complicated

In addition, the resonance state is an unstable state. The operating frequency of the motor is easily affected by many factors, such as the precision error of the motor processing and assembly, and the frequency consistency adjustment problem, which is often difficult to optimize to improve the frequency consistency problem. , the result will cause the motor to deviate from the working resonance frequency, resulting in a decline in the output performance of the motor and even affecting the normal operation of the motor. The working environment is more serious when the temperature is high and the temperature is high, and the performance of the motor is degraded or even damaged.

[0005] In recent years, the development of non-resonant piezoelectric motors has been booming. Some researchers have proposed to use the characteristics of piezoelectric stacks under non-resonant conditions to develop piezoelectric motors with high positioning accuracy, but the current piezoelectric motors are generally There are disadvantages of small stroke and low precision

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