Theoretical And Experimental Study On Failure Form And Mechanism Of High Bearing Precision Ball Screw

Ball screw is an important linear transmission component for the space transmission system. Due to the particularity of working condition of the space, the workload of ball screw is often greater than the rated load, and the failure modes of ball screw will be different from the conventional failure modes. Therefore, the research on the failure modes and mechanism of ball screw on the high load condition is very importantIn view of the real deformation characteristics of material on the high load case, according to Hertz contact theory, the paper firstly established a kind of contact model and put forward the calculation method and solving process of the elastic-plastic deformation between the ball and the raceway surface. On the basis of these theories, the paper analyzed the plastic flow of raceway material and the characteristics of sliding friction under high load condition, and found that the ball screw may have four kinds of failure form due to the large plastic deformation at contact points, namely:the damage of raceway surface, such as micro cracks or abrasion of raceway surface; the fracture of screw gear; the ball locked; precision failure caused by axial large clearance. Finally, according to the principle of rolling strengthening of metal surface, in order to improve the axial stiffness and ultimate bearing capacity, the paper researched a kind of strengthening method suitable for the ball screw groove surface.On the basis of theoretical analysis, the paper have made a series of experimental research, and observed the appearance of the raceway surface after loading to verify the failure modes. Then the paper made the research on the results of the surface strengthening, the rationality of theoretical analysis was verified by the experiments, and the research results provide a theoretical and experimental basis for the design of ball screw on the high load condition.