In this paper, we describe the most important steps in the development process of a new high-efficiencypiezomotor. The device utilizes one commercial piezoelectric element, a compliantcoupling structure and an output rotor mechanism which is of virtually unlimited travel range. Thecompliant structure serves as an interface between the piezoelectric element and an output shaft; itconverts the output motion of the piezoelectric element tip into driving motion of the output shaft.The output shaft activates a single step summing drive based on a stick-slip principle. We willpresent the basics behind coupling design, and then we will move into prototype fabrication andmeasurements. Since the performance of piezoelectric actuator is related to the load it drives, thedesign is prefaced with a load matching discussion based on an optimization study of the structuraldesign. The load matching conditions will be addressed in order to maximize the energy anddisplacement transfer from the piezoelectric bender to the output shaft. Based on these guidelines, anew piezoelectric drive was designed. The piezoelectric drive which has significantly betterperformance than a pure flexural amplification is presented. Detailed design description andtheoretical analysis of the output mechanism to accumulate the discrete steps in the rotationalelement is provided. Since the present device is not an "ultrasonic motor", there is no restriction onthe frequency of the input electric signal and the motor can be controlled by the input signalcharacteristics.
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