Design And Research Of Ultrasonic Vibration Grinding System For SiC Optical Elements

SiC materials,which have excellent material properties,of high hardness,large thermal conductivity,small thermal expansion coefficient and high chemical resistances.However,the special material performance of SiC sets higher requirements for processing method.Traditional processing methods have the defects of inefficient,easy to bring cracks and crumble.It not only increases the processing cost,but also brings greater burden to subsequent polishing.In this paper,the ultrasonic grinding system for processing SiC material optical elements is taken as the research object.The structure design,finite element simulation and non-contact electrical signal transmission of ultrasonic vibration grinding system are studied.The specific research contents of this paper is as follows.The components and functional requirements of ultrasonic vibration grinding system for SiC part are determined,and the structure of ultrasonic vibration grinding spindle is designed.The static and dynamic characteristics of the ultrasonic spindle are simulated and analyzed,and the maximum deformation and critical speed of the spindle are obtained.Designing the main shaft support mode and adopting series bearing group.According to the power required for ultrasonic grinding of ceramic parts,ultrasonic power supply and electroplated diamond grinding wheel are designed.The structure of piezoelectric transducer is designed based on full wavelength ultrasonic transducer theory.The simulation is conducted by used of finite element software Ansys,and the results demonstrate that the piezoelectric transducer is vibrating longitudinally,and the frequency and amplitude are up to the requirement.The ultrasonic grinding oscillator is processed,and the resonant frequency of ultrasonic vibrator is slightly lower than that of simulation.The maximum amplitude of the end face of the grinding wheel can meet the requirements of ultrasonic machining for ceramic parts.A new type of non-contact electrical signal transmission device considering the influence of distributed capacitance and leakage inductance is designed based on the electromagnetic induction principle to solve the problems of large friction,severe heat,large vibration and low speed in the traditional contact electric signal transmission mode.The structure size of the porcelain tank of the ultrasonic frequency electric signal non-contact transmission device is calculated,and the transmission theoretical model is established.The influence of measured distributed capacitance and leakage inductance on the transmission performance of electrical signal non-contact transmission device is studied.A solution to increase the air gap of porcelain tank and reduce the distribution capacitance and leakage inductance is put forward.The results show that the smaller the air gap of the porcelain tank,the higher the transmission efficiency,and the amplitude output can be stabilized at 8 m,which meet the requirement of ceramic parts ultrasonic vibration grinding.