Research On Piezoelectric Linear Motors Based On Displacement Amplification Structure

This project was granted by the project of the National Natural Science Foundation of China.(Contract No:50575103).Piezoelectric linear motors based on piezoelectric effect have advantages of high positioningaccuracy, power locking, high power density, and no electromagnetic interference, which werewidely applicated in the field of ultraprecision manufacturing and positioning.Piezoelectric stacks have advantages such as large vibration amplitude, low driving voltage,according which two types of non-resonant piezoelectric linear motors based on displacementamplification structure were proposed in this paper. Compared to thoses existed non-resonant linearmotors, the new proposed motors have better stability with good linearity between the output speedand driving frequency. The main research contents in this paper are briefed as follows:Introduced the types and application scope of displacement amplification structures, studiedthe deformation characteristics of the flexible hinge, and proposed a structure design method tokeep the piezoelectric stack from shear forces, which provides foundation of the stator and stackprestressing structure design of the motors.Working principle and design method of a piezoelectric linear motor based on leverage wasproposed, and its operating course was detailed. Using Finite Element Software ANSYS, theparametres of the stator were optimized. On the foundation of the prototype experiments, a newimproving scheme was established.On the basis of leverage and triangle amplification principle, a combination amplificationstructure was raised and designed, which was utilized in a new type of piezoelectric linear motor.The parameters of this motor was optimized by Finite Element Software ANSYS, meanwhile, theharmonic response analysis was carried out.Experiments on the two linear motors were done, the experimental results showed the motorbased on lever structure outputed steadly in low frequency without stagnation.The effect of drivingfoot elliptical track changes on the motor performance was studied by adjusting mechanism in thecombination motor and the linearity of output speed with driving frequency was better than existednon-resonant motors, which achieved the design objectives.