Simulation Design And Performance Study Of A Piezoelectric Ultrasonic Transducer For Bearing Fault Detection

Ultrasonic technology has developed rapidly in recent years,and ultrasonic transducers,as the core application of ultrasonic technology,have become more and more popular in the field of nondestructive testing.In order to make the structure and performance of ultrasonic transducer suitable for the overall inspection system,and design a signal conditioning circuit to amplify the signal collected by the transducer after processing,become a key problem to be solved.To overcome this difficulty,this paper develops and designs a piezoelectric ceramic ultrasonic transducer for bearing fault detection and a signal conditioning circuit for processing the collected signals.First,an ultrasonic transducer is developed for the shortcomings of some ultrasonic transducers such as narrow bandwidth,low sensitivity and low applicability.The structure of the transducer is constructed according to the working mechanism and application of the ultrasonic transducer.According to the theory related to the material and size of ultrasonic transducer,the core element piezoelectric ceramic piece is designed,and finite element model is created to determine the center frequency of the transducer through harmonic response analysis,and the working bandwidth of the transducer is determined by analyzing the transmit voltage response curve of the transducer,so as to complete the structural design and simulation analysis of the ultrasonic transducer.Secondly,a signal conditioning circuit for bearing fault detection is designed for the problems of high impedance of ultrasonic transducer and weak acquisition signal.The actual performance index of the ultrasonic transducer is combined with the application scenario,the circuit gain is set,and the op-amp is selected according to the influence of gain,noise and zero drift on the circuit.Combining circuit gain and transducer bandwidth range,the values of feedback capacitance and feedback resistance are determined,so as to achieve the main function of amplifying the collected signal of ultrasonic transducer with less error.Finally,the sample development and experimental verification of the piezoelectric ceramic ultrasonic transducer are carried out.The samples of the ultrasonic transducer structure design are developed,and the main performance parameters of the developed samples are tested to analyze whether the indexes meet the design requirements.By establishing a rotary bearing simulation platform,the ultrasonic data collected by the applied transducer is processed to obtain time domain maps of different operating conditions of the rotary bearing,thus verifying the usability of the piezoelectric ceramic ultrasonic transducer.