| The pretightening force of high speed ball screw can effectively improve the operating precision and the axial stiffness of the screw and increase the carrying capacity. However, the pretightening force will gradually lost, and the pretightening force will affect the comprehensive performance directly. It has become a very important problem for many domestic manufacturers to solve that how to improve the stability of the pretightening force.The main factors of the loss of the pretightening force were analyzed from the angle of wear by using Archard wear theory and Hertz contact theory. The main reason for the loss of the pretightening force when the ball screw is processed and used were determined after communicating with the manufacturer.The finite element model of ball screw were established using Pro/E and ABAQUS to be used to study the loss of pretighening force under different contact angles and different shim parallelism.Based on comprehensive performance test bench, ball screws with different materials and running speeds were experimented to compare the speed of loss of pretightening force. A ball screw made in foreign was experimented to compare with the domestic one to study the disparity between them.Using the theory of friction heat and heat convection, a model to calculate the temperature rise of ball screw under pretightening force was put forward. And the correctness of the model is verified by experiments. The formula for calculating the thermal elongation were analyzed, and experimental results were compared with formula to find out the deficiencies of the formula.From the perspective of ball’s energy, the main source of vibration and noise of ball screw is explored. According to the results of the analysis, the suppression measures were put forward. The vibration and noise with different speeds and different pretightening force are analyzed by experiments.
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