Study On The Clamping Stepper Piezoelectric Linear Motor

With the development of science and technology, the precision driver requires not only high resolution but also enough output force with high stiffness. Traditional electromagnetic drivers can not meet these requirements. On the contrary, inchworm-type piezoelectric motor appear to meet these requirements, and it has been widespread concerned at home and abroad. Var ious piezoelectric inchworm-type drivers were successfully developed.Traditional piezoelectric inchworm-type linear motor has two clamping devices and one driving device, using bionic principle of movement clamp-drive-clamp, to achieve two-way and stepping motion. Because the deformation of the clamp device relative to the average processing tolerance is very small, it is difficult to ensure the gap keep the same when the moving part is moving. This is why the piezoelectric inchworm-type motor requires for high machining and assembly accuracy. This paper takes the research on the piezoelectric inchworm linear motor, in order to reduce the demands on the machining and assembly. The main research contents are as follows:The basic characteristics of piezoelectric stacks were presented. And the issues which should be noted in use were summarized. In order to obtain a basis for the design of motor, the dynamic characteristic experiments of two type piezoelectric stacks were carried out. And the relationship between applied pressure and generated voltage of the laminated piezoelectric based on the principle of positive piezoelectric effect measuring was tested.The clamping stepper piezoelectric linear motor is designed and the prototype is fabricated. the experiments on the prototype were carried out. Experimental results show that, the relationship curve between the no-load speed of the motor and driving voltage is linear, and the relationship with the frequency is nonlinear, the speed will be greatly decreased when the frequency increases to a certain extent, the maximum speed is 1.21mm/s; and the maximum output force is 1.8N.In view of the problem of insufficient output force of the motor, the motor is improved, and a new prototype is made. The experiment results proved the feasibility of the improvement scheme. The new structure of the motor has a litt le effect on the maximum speed, but it can effectively increase the adjusting scope of the frequency. Finally, the motor's maximum output pow er is increased to 4.5N.