## 1 Introduction
The ball screw is a typical high-friction pair, the contact between the ball and the raceway is a point contact, and the mechanical properties and contact characteristics are different from line contact and surface contact. At the same time, there are relatively few studies on the application of surface texture to the ball screws. Therefore, it is important to study the application of surface texture in ball screws and analyze the EHL and the contact characteristics between the ball and the textured raceway, which play an important role in improving the friction reduction, wear resistance, and service life of ball screws. Numerous researchers have studied the influence of surface texture on the EHL characteristics based on the smooth surface of the workpiece. Simultaneously, they believe that the contact pressure between the ball and screw is borne by the lubricating oil film, ignoring the influence of the rough and uneven surface topography on the EHL and contact characteristics. In practice, however, it is not possible for the raceway surface of the ball screws to be absolutely smooth. Simulations and experimental measurements show that surface roughness and lubricant film thickness are usually of the same order of magnitude. Therefore, it is necessary to consider the influence of the ground surface topography of the raceway on the EHL characteristics of the textured raceway of the ball screws. This paper attempts to apply the surface texture technology on the raceway surface of the ball screws to achieve the purpose of reducing the friction and wear of the ball screws, improving the efficiency and accuracy retention of the ball screws. The influence of the ground surface topography on the EHL of the textured raceway of the ball screws is considered. The grinding surface topography of the screw raceway is constructed according to the formation mechanism of the grinding surface and the geometric model of the raceway surface of the ball screws. Simultaneously, the surface topography of the machined screw is measured and compared with the theoretical simulation to verify the correctness of the surface topography model of the screw raceway. Considering the ground surface topography of the screw raceway and geometric features of the textures manufactured on the raceway surface, the EHL model of the textured raceway of the ball screws with point contact is established, and the finite difference method is used to solve the EHL characteristics of the textured raceway of the ball screws. The friction reduction mechanism of the textured raceway of the ball screws and the influence of the geometric features of the textures on the anti-friction properties of the ball screws under different axial loads and rotation speeds of the ball screws are investigated and discussed. In order to quickly reflect the anti-friction characteristics of the EHL of the textured raceway of the ball screws, the proof-of-principle experiments of the friction-reducing performances of the textured raceways of the ball screws are conducted based on the contact state and mechanical properties between the ball and the textured raceway of the ball screws. The effects of textured workpieces with different geometric features on the friction reduction performance of the EHL under different rotation speeds and axial loads of the ball screws are further analyzed and discussed. The experimental results verify the correctness of the EHL model of the textured raceway of the ball screws and the effectiveness of the anti-friction performance of the surface texture technology of the ball screws.