Axial Static Stiffness of Ball Screw Feed Drive System Incorporating Flexibility of Ball Screw and Rolling Bearing

Axial static stiffness is a main technical indicator for the ball screw feed drive system, and the elastic deformation outside the Hertz contact zone of the system affects its axial static stiffness. However, the influence of elastic deformation outside the Hertz contact zone on the axial stiffness has not been studied thoroughly. This study was to establish a flexible model of axial stiffness for the feeding system with considering the elastic deformation outside the Hertz contact zone. The axial stiffness of the feeding system was calculated using the proposed flexible model, and the model was verified by measuring the axial stiffness of the feeding system. The results show that the proposed flexible model can be more accurate compared with the conventional rigid model, and the method to analyze the elastic deformation outside the Hertz contact zone is practicable.