Electromagnetic torque analysis for a non-contact piezoelectric motor modulated by an electromagnetic field

摘要

For a non-contact piezoelectric motor modulated by an electromagnetic field, the design scheme of a piezoelectric micro-displacement amplifying mechanism is described. The relation formula between the output displacement of piezoelectric stacks and the output angle of the mechanism are given. Using the theory of electromagnetism, the static output torque equation of electromagnetic coupling mechanism based on the output angle of the piezoelectric amplifying mechanism is established, and the effect of system parameters on the static output moment is analyzed. Considering this piezoelectric motor driven by a square wave signal, the dynamic output torque equation of the non-contact piezoelectric motor is established, and the effect of system design parameters on the dynamic output torque is revealed. The analysis results show that the different output step precisions of the piezoelectric motor can be obtained by adjusting the length of the bar 1. A reasonably selected output angle is beneficial to increase electromagnetic torque. When the air gap is reduced to improve the torque, a larger output torque can be obtained by designing a reasonable output angle. At a certain amplitude of modulation voltage, the reasonable combination of external resistance and modulation signal frequency is beneficial to the design of an ideal dynamic torque response waveform and larger dynamic torque amplitude. The above analysis results can lay a theoretical foundation for the design of a high-performance non-contact piezoelectric motor modulated by electromagnetic and the optimization of the drive scheme.