The Research On The Application Of Piezoelectric Ceramic In Ultrasonic Motor

Ultrasonic motor using the inverse piezoelectric effect of piezoelectric ceramics change the electrical energy into mechanical energy, and change mechanical vibration energy into the motor rotation (straight line) movement through the frictional force, and then drive the load. Piezoelectric ceramics as the vibration device of Ultrasonic motor, its performance will directly affect the motor output. In this paper, the P-41 and PMnS-PZN-PZT piezoelectric ceramics are prepared through the conventional solid phase sintering in order to obtain the application of piezoelectric ceramics in ultrasonic motor and their correlation.We study the P-41 and PMnS-PZN-PZT piezoelectric ceramic materials structure, properties, frequency temperature stability and the effect of polarization manner on piezoelectric ceramics. It shows that they both have better dielectric temperature stability. P-41 has obvious characteristics of ferroelectric phase transition, PMnS-PZN-PZT has relaxor-ferroelectric phase transition. Using once polarization process at the same time will reduce the polarization time and improve the ultrasonic motor output performance, while the polarization regional of twice polarization process is uneven and d33 is lower due to geographical interface stress. P-41 ceramic polarization conditions are 3 kV/mm,120℃polarizing 15 min, PMnS-PZN-PZT ceramic polarization conditions are 3.5 kV/mm,140℃polarizing 15 min.The correlation between the P-41 and PMnS-PZN-PZT piezoelectric ceramic and ultrasonic motor is studied. And explore the admittance of the motor, load, start and shutdown and temperature characteristics. It indicates that two motor have good transient characteristics, start-up time<2 ms, off time<1 ms. The P-41 piezoelectric ceramic motor start and shutdown is faster than PMnS-PZN-PZT piezoelectric ceramic motor which due to P-41 piezoelectric ceramic with non-relaxation characteristics of the phase transition, indicating P-41 piezoelectric ceramic is more suitable for repeated switching of the ultrasonic motor needs. Meanwhile, P-41 motor have smaller Qm and larger keff (TRUM-60 I motor), and better load drive capability. Motor surface temperature increased rapidly with the running time, and eventually run at a stable operating temperature. Using PMnS-PZN-PZT piezoelectric ceramic motor'surface temperature is significantly lower than P-41 piezoelectric ceramic motor (TRUM60II motor)which due to PMnS-PZN-PZT piezoelectric ceramics with very low dielectric loss, and indicating it is suitable for the material needs of long-term operation of the ultrasonic motor. The effect of Pre-stress on the motor performance is very important. Different sizes of motors have different drive performances.