The Research Of Kinematic Characteristics Of Balls And Their Influence Factors On The Rotated Dual-plates Lapping Platform

High precision ball, as one of the most important element of high precision bearing, roundness measuring equipment and other high precision machine apparatus, cann't be acquired at a high efficiency and a low cost because of limitations of traditional lapping process. Futhermore, the uniformity and stability of processing are low. In order to overcome these problems, Ultra-precision Machining Research Center of Zhejiang university of technology advanced a new type of high precision and efficiency method. It's called rotated dual-plates (RDP) lapping. Under this lapping mode, two down plates are driven to rotate respectively at designed speed to achieve better uniformity of lapping trace distribution on ball surface. This has improved lapping accuracy, sphericity error and effciency. However, the final processing precision is also affected by processing condition or structural failure of device, which result in the different motion of ball between reality and theory. In order to solve the problems above, this paper has analyzed the kinematic characteristics of ball and the effects of motion through numerical methods, simulation and experiments.Firstly, the ball's kinematic characteristics at different conditions is studied. By establishing equilibrium equations, the paper analyzes the phenomenon of skidding and rolling of the ball during processing, and also the cutoff between two states. Futhermore, the analyzed object is enlarged to more balls. And the forces equation are derived to know the motion of balls deeply. In order to analyze kinematic characteristics of ball and RDP lapping machine easily, compendious introducation of virtual prototype technology and ADAMS are been used to establish 3D simulation model based on the optimized equation of two down plates'rotation. The model has verified the kinematics model and the structure desige. Then influence factors of balls'motion are studied by the model, especially the variation of V-shaped groove and the error of incline of lapping plates.The second part is about lapping experiments. On RDP lapping platform, lapping trace distribution on ball surface is studied by establishing a simple method for detecting and calculating motion parameters. And by the way above, motion parameters of balls are aquired at different load and abrasive liquid to prove results of numerical model and simulation model. Moreover, the steel ball which has reacted with CuSO4 is processed to verify the better lapping uniformity of RDP lapping mode directly and effectively. While the processing precision of ball, as main research object, is affected by load, velocity, density of grinding fluid and so on. On the basis of Taguchi method, the processing parameters are studied for the balls'final precision and lapping efficiency by the same device, and the most effective processing condition is acquired. Amony parameters of the ball's precision, sphericity error is the most significant manifestation of ball's motion, so the weight of lapping parameters for sphericity error is studied by Variance. The results show that the influence of load is the most obvious, the next are velocity, unknown factors and abrasive concentration. This also reflects the degree of influence of processing parameters for ball's kinematic characteristics.