| To improve the sphericity and processing uniformity of precision ball, a new type of ball lapping method - Rotated Dual-Plates (RDP) lapping method was proposed. Under RDP lapping mode, two down plates are driven to rotate respectively in designed speed combination to achieve better uniformity of lapping trace distribution on ball surface, which will obtain a homogeneous, quick spherical deviation of the amendment, so as to improve machining precision and machining efficiency. Despite a lot of research has done on basic theory and key technology of RDP lapping method, but there has no exact description of the impact of errors on the ball machining. Based on this, the impact of mechanism errors on uniformity of ball lapping are studied in this paper. It is of great significance to perfect the theory of RDP lapping method and optimize the geometry mechanism of RDP device.When RDP lapping method is in the ideal and no mechanism error state, the relations between ball motion parameters in the lapping process are deduced through theoretical calculation and numerical simulation in geometry or kinematics model. The conditions and degree are studied to meet the probability of grinding cutting under RDP lapping mode. A uniformity valuation method for lapping trace is also put forward, and quantitative analysis of spherical uniform distribution of lapping trace is discussed through numerical calculation. Finally, the ideal combination of lapping plate speeds and other relevant parameters are fixed.In order to overcome the impact of RDP lapping mechanism error to precision ball, mainly study for the four kinds of errors that may exist, they are: 1) the inside down lapping plate occurs jump when in the lapping process; 2) the inside down plate tilt; 3) the outside down plate is not round, and exist two projections; 4) groove angles change. It can be get equations of grinding trace by calculating the ball motion parameters under various corresponding errors. The spherical lapping traces are simulated using MATLAB simulations in different values of related errors, and the distributions of ball motion traces are drawn. Then evaluate the trace uniformity according to the standard deviation SQ of the number of spherical lapping trace points. Use the ADAMS software to establish a virtual prototype model of RDP lapping mode, and through dynamic simulation, the changes of the ball rotation angleθ, rotation speedωb and revolution speedωin various forms of error conditions are analyzed and compared. The various error factors on the accuracy of ball lapping are judged in this paper.To verify the theoretical simulation results, select the radial error of the inside down plate for ball lapping experiment. Set the values of radial errorsΔhj were respectively 20μm, 50μm and 80μm when ball billet processing, and compared with the result under traditional V-groove lapping mode. The impact on processing results is obtained by comparing the sphericity and degree of lapping uniformity. The experimental results are generally consistent with the conclusions of the corresponding theoretical calculation and simulation.Finally, it can get the following conclusion through research: When the spherulization mechanism of RDP lapping method has tiny errors, it will cause certain effect on ball machining but little, and the effect is within the allowable range mostly. Compared with the traditional V-groove lapping method, its error factors on accuracy of ball machining can be neglected.
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