Study On Contact And Lubrication Characteristics Of Ball Screw Based On Surface Texture

For a country's manufacturing industry to develop in the direction of higher precision and higher speed,the ball screw is bound to play an important role.The ball screw is one of the important parts of the transmission system of CNC machine tools.The transmission precision and speed are closely related to the machining accuracy and efficiency of the CNC machine tools.The higher transmission precision and speed of it,the higher machining precision and speed of the CNC machine tool will be.However,the high speed of ball screw will lead to serious problems such as serious wear and large deformation.These will affect the accuracy and service life of ball screw transmission to a certain extent,and then affect the machining accuracy of CNC machine tools.So it is necessary to explore the performance of ball screw in various aspects.In this paper,the ball screw of the X axis feed system of GSCK200 A CNC machine of high speed and high precision are used as the research object,the contact and lubrication characteristics of ball screw with texture and non texture on the surface of the screw raceway are simulated and analyzed,and the analysis results of the two are compared,the aim is to investigate whether the friction and wear of the ball screw can be reduced when the surface of the screw raceway is textured.The main contents of this paper are as follows:(1)Through reading a lot of documents,the current research status of ball screw in the direction of friction reduction and lubrication is known,and the research status,research methods and achievements of surface texture is also known.(2)By using the Hertz contact theory,the contact stress and contact deformation are calculated for the ball screw without texture on the surface of the screw raceway.The relation schema of the axial force and the contact stress and the contact deformation is drawn.The surface texture of a parameter is designed on the surface of the screw raceway,and a contact stress calculation model for two contact surfaces with texture structure is given.(3)The contact analysis of the ball screw with non texture and have texture on the surface of the screw raceway under the different axial displacement is carried out by ANSYS,the analysis results of the two are compared and discussed;Changing the parameters of the texture of the screw raceway,the influence of the surface texture of different parameters(shape,size and position)on the contact stress of the ball screw is analyzed one by one.(4)The origin and the influencing factors of the friction and wear of the ball screw is described in detail.The existing antifriction measures of ball screw and antifriction mechanism of surface textureare are discussed too.(5)Basing on the Reynolds equation and the minimum oil film formula of Hamrock-Dowson,the expression of the minimum oil film thickness of the ball screw with non texture and have texture on the screw raceway surface is derived,and the lubrication state of the ball screw under the general rotational speed is obtained;The fluid lubrication simulation analysis is carried out on the simplified model of ball screw with non texture and have different parameter texture structure on the screw raceway surface by FLUEN T and the results of the analysis are compared and discussed,and the corresponding conclusions are obtained.