Research Progress of the Rotating Ultrasonic Motors Based on In-plane Mode
The ultrasonic motor works based on the inverse piezoelectric effect of piezoelectric ceramics and mechanical resonance to obtain its motion and torque.It has a lot of excellent merits,such as fast response,high positioning accuracy and can be directly driven.It has unique application advantages in fields such as precision drives,aerospace,biomedicine,etc.Several mature products have been successfully applied and industrialized.Currently,micro ultrasonic motors based on in-plane vibration modes are the most prone to miniaturization,and have great potential and space for application in the field of micro-electromechanical systems.Firstly,the working principle of ultrasonic motors was introduced.Secondly,two types of in-plane driving rotary ultrasonic motors were reviewed in terms of two stator structural forms,namely sandwich type transducer stator structure and patch type stator structure.The new developments and achievements in relat-ed research were summarized from different structures,output performance,and application research.More-over,the main performance of several motor prototypes was compared and analyzed.Finally,several issues were pointed out that require further research and breakthroughs.