Mechanism Study And Simulation Analysis On The Lapping Of Precise Resin Ball

Precise resin ball is an important part of fine measuring equipment, such as navigation system, medical B-instrument. In order to obtain high precise resin ball, lapping is the most commonly used method. Because of the special mechanical characteristics of the resin ball, such as viscoelastic, low friction coefficient, low elastic modulus and so on, the movement of the balls are not ideally during the lapping process. It's easy to slip and wear.As a result, the spherical deviation can't be improved, the application of resin balls is limited.In order to solve the above issue, this paper has analysed the characteristics of the lapping movement of the balls and it's affecting processing parameters by theoretical analysis and simulation.An improvement is put forward based on the above analysis, and verified by an observed experiment.The processing factors impacted the movement of the balls in lapping are analyzed by studying the process of lapping balls and the influence parameters of the tribology of resin. The removal model is related with the movement of the balls during the lapping. Analysis on the influence parameters of the single point wear of rolling ball and sliding ball by plane lapping experiment of the ball. Then the parameters impacted to the movement of the balls are obtained, and the reasons caused the sliding of the balls are came to a dicision.Based on the traditional V-shaped groove lapping, this paper has established the mathematical model of the motion characteristics of the balls. The concept of sliding is introduced in order to evaluate the level of the sliding of three contacting points. The impact of sliding to spin, revolution and spin angle of the sphere is analysed. The dynamic equilibrium equations of force and torque have been established, and the impact of lapping pressure, plate speed and lapping conditions to the movement state of the balls, which are rolling and sliding, is analysed. An improvement is put forward and analysed by simulation. This method doesn't change three contact and lapping points, and a friction pad is added at the bottom of V-shaped groove to increase the revolution friction force, which can prevent sliding; the ball's spin angle direction is changed by a device independently so as to solve the problem of"no change of spin angle"in traditional V-shaped groove lapping method.In order to verify the theoretical analysis of the processing parameters and improved methods, observation experiments of the movement of the balls is designed. Single-factor experiment is used to analyse the impact of the processing parameters on the movement of the balls by observing the scale engraved on the ball and V-rail. At last, the effect of new lapping method is verified by comparing with the original method with experiment.