Analysis Of Modal And Stiffness Characteristics Of Ball Screw Pair

Ball screw pair is widely used in various kinds of sophisticated industrial equipment and CNC machine tool because of its high precision, rigidity and stability characteristics of movement etc. However, with the need of the development of high speed cutting technology,the requirements for ball screw pair also increased. Ball screw pair also develops in the direction of high speed constantly, and generates the following problems about motion noise,vibration and motion reliability problems. So, in this thesis, ball screw pair of modal and axial contact stiffness should be researched and analyzed deeply.This thesis commences from the modal analysis of ball screw pair, the ball screw is analyzed respectively in free modal and constraint modal analysis. Achieves a more accurate frequency and amplitude parameters of each order of ball screw pair, The influence of the nut on the modal parameters of the nut on the screw is studied. The joint surface of the ball and the thread raceway is modeled. Gets the nut of axial displacement variation additional under the action of axial force. The axial stiffness of the ball screw is analyzed by ANSYS. The axial displacement of the ball screw is obtained by the axial load,and the axial stiffness is obtained.And the influence of the nut position on the side stiffiiess of the ball screw was obtained Build a test bench, The overall axial stiffness of the ball screw pair in the different position of the screw is measured, And the simulation results are experimentally verified.Through the analysis of the axial stiffness of the ball screw,the combination of simulation and experiment, the axial stiffness of the ball screw is accurately measured, and the influence of the nut on the stiffness value at different positions of the screw is explored, provides precise control parameters for NC machine tool control system.