The Analysis And Research Of Stiffness And Efficiency For Planetary Roller Screw

Planetary roller screw with its characteristics of high speed,overloading,high efficiency,long life and so on, has been widely applied to a variety of the occasion of precision transmission linear and high-thrust, gradually has been the first choice of heavy and high precision line-transmission parts instead of ball screw. However, due to the basic theory of the Planetary roller screw was still in the initial stage in the domestic, and there weren't appropriate theoretical basis and calculation model on the importent performance indicators such as stiffness,friction,efficiency and so on. This paper mainly analyzed on these performance, and then studied on its main influencing factors. These all provides a good theoretical basis for the structure optimization and research and development of products of the planetary roller screw.Firstly, This paper built the mathematical model and numerical analysised on the contact deformation of the planetary roller screw followed by the Hertz theory and Fractal theory, and then the computing result were compared; Secondly, taken into consideration the factors of the torsional and axial tension and compression deformation of the screw, the axial tension and compression deformation,contacting deformation,thread deformation of the vice assembly, the mathematical model of load distribution for the planetary roller screw have been built and calculated, and then the axial static stiffness were analyzed and calculated, the influencing factors of the the axial static stiffness such as the manner and size of the preload,helix angle,contacting angle and so on were discussed and analyzed simultaneously; Then the generation mechanism of the friction for planetary roller screw, and the influencing factors such as preload,Processing error,Lubrication characteristics and so on were discussed and analyzed simultaneously; Lastly, the mathematical model of efficiency were built and calculated, the influencing factors such as helix angle,contacting angle were analyzed.The innovation is that as followed: built the mathematical modeling of the contact stiffness for planetary roller screw with the fractal theory, and then compared with the hertz theory. Then built numerical molding of the axial static stiffness,friction and efficiency for the planetary roller screw, and the influencing factors were analyzed and discussed. The result of the research provided a basis theory and reference value for the structure optimization, products research & development and application, and also laied a certain foundation for the further basic theory research of planetary roller screw.