Analysis And Test Method Of Static And Dynamic Characteristics Of Linear Rolling Guideway Joints

Linear rolling guideway pair is an important feed motion functional component in CNC machine tools,which has the features of high guidance accuracy,sensitive response,and high precision assurance and is widely used in CNC machine tools and other fields.However,the linear rolling guideway components used in my country’s high-end CNC machine tools basically rely on foreign brands.In order to break the monopoly of foreign brands,the research and development of domestic high-end linear rolling guideway products has been highly valued by research institutions and business circles.The static and dynamic characteristics of linear rolling guideways directly affect the performance of CNC machine tools.Therefore,it is of great significance to study the static and dynamic characteristics modeling and test methods of linear rolling guideway joints to improve the design and development of domestic high-end linear rolling guideway products.This paper starts with the static and dynamic characteristic parameters of the joint surface and studies the static and dynamic characteristic modeling and experimental test methods of the ball-raceway joint surface,the static and dynamic characteristic modeling and experimental test methods of the linear rolling guideway joints,and the modeling and experimental test methods of oil film damping.The main research contents are as follows:(1)A test platform for the static and dynamic characteristics of the joint surface is designed,an experimental test model is established,the relationship data between the normal deformation of the joint surface per unit area and the surface pressure are obtained,and the characteristic parameter formula of the normal static stiffness of the joint surface per unit area is obtained.The calculation formulas of the characteristic parameters of the normal dynamic stiffness and damping of the joint surface per unit area with the normal surface pressure,excitation frequency and dynamic displacement amplitude arc fitted.(2)The static stiffness,dynamic stiffness and damping analytical models of the ball-raceway joint are established,and the corresponding test system is designed and developed.Based on the normal static and dynamic characteristic parameters of the joint surface,an analytical model for the static stiffness,dynamic stiffness and damping of the ball-raceway joint surface are established.The tests verify the validity of the established ball-raceway joint surface analytical model.The effects of static load,excitation frequency and dynamic displacement amplitude on the dynamic characteristics of the ball-raceway joint surface are simulated and analyzed.(3)The static stiffness,dynamic stiffness and damping analytical models of the linear rolling guideway joints are established,and the corresponding test system is designed and developed.Based on the static stiffness,dynamic stiffness and damping model of the ball-raceway joint surface,an analytical model of static stiffness,dynamic stiffness and damping of the linear rolling guideway joints is established considering the change of the contact angle and the influence of the off-sized ball.The static stiffness,dynamic stiffness and damping of lateral,normal,pitch,yaw and roll are solved.The test verifies the validity of the established analytical model for the static and dynamic characteristics of the linear rolling guideway joints and analyzes the changing law of the dynamic stiffness and damping of the linear rolling guideway joints with static load,excitation frequency and dynamic displacement amplitude.(4)Based on the Navier-Stokes equation of viscous fluid and the principle of damping energy dissipation,an analytical model of tangential oil film damping per unit area between plates with periodic oscillation is established.According to the dynamic model of tangential oil film damping,a method for identifying tangential oil film damping per unit area is proposed,and a tangential oil film damping test device is designed to conduct sinusoidal excitation tests for different oil film thicknesses and different types of mechanical oils.The established analytical model of tangential oil film damping per unit area is verified by tests,and the influence of oil film thickness and oil viscosity on the tangential oil film damping per unit area is analyzed.Through the test analysis of the tangential damping characteristics of INA’s damping slider,it not only verifies the validity of the established analytical model of tangential oil film damping per unit area,but also provides a basis for further application of oil film damping.