设计了一种超声悬浮轴承用新型径向挤压式压电换能器, 用于验证超声波轴承径向共振频率理论计算的正确性。基于弹性理论、压电方程和机电类比原理, 建立压电换能器机电等效电路图, 理论推导出了压电换能器径向振动的共振频率方程; 然后, 应用Matlab软件计算出了压电换能器的共振频率。采用有限元软件对已知结构尺寸的换能器进行模态分析, 计算出压电换能器所需振型及该振型下的共振频率, 数值仿真分析了换能器结构尺寸对换能器共振频率和径向振幅的影响。最后, 设计了 一台样机, 从理论、仿真及实验三方面对其共振频率进行验证。实验结果显示: 换能器径向振动共振频率的理论值与实验结果相对误差为5.89%, 仿真值与实验结果误差为3.53%。实验结果证明了理论计算方法的正确性, 为压电挤压换能器的设计提供了理论依据。

A new type radial extrusion type piezoelectric transducer for ultrasonic levitation bearings was designed to verify the correctness of the theoretical calculation of ultrasonic bearing radial resonance frequency. Based on the basic theory of elastic, piezoelectric equation, and the electromechanical analogy principle, the mechanical and electrical equivalent circuit diagram for the piezoelectric transducer was established, and the resonance frequency equation of the radial vibration of the piezoelectric transducer was deduced. Then, MATLAB software was applied to calculation of the resonant frequency of piezoelectric transducer, and the finite element software was used to analyze the modal of the known structure size of transducer, calculate the resonance frequency of the piezoelectric transducer under the required vibration mode and simulate and analyze the impact of transducer structure size on resonance frequency and radial amplitude of the transducer. A prototype was designed and its resonant frequency was verified on the basis of theory, simulations and experiments. Result shows that the relative errors of theoretical and experimental results and simulation and experiment results for the radial vibration resonance frequency are 589%, and 353%, respectively. These results verify the correctness of the theoretical calculation method and provide theoretical basis for the design of extruded piezoelectric transducers.