行星滚柱丝杠参数设计及静态力学性能分析

Abstract

As a relatively new servo transmission mechanism, the planetary roller screw has excellent performance. It has been widely used in aerospace, weaponry, and numerical control machine tools, and has rapidly replaced ball bearings in high-thrust applications. The bar linkage has become the main transmission mechanism of the linear servo system and it is believed that it will be more widely used in the future.However, the research on planetary roller screw is relatively late in China, and the basic design theory is not perfect. Therefore, the design of planetary roller screw parameters is studied in this paper, and its static mechanical properties are analyzed.

In this paper, the composition and working principle of the standard planetary roller screw are introduced briefly. Based on this, the kinematic model of the standard planetary roller screw pair is established based on the spatial cross thread engagement principle. The key thread parameter relationship was deduced. Based on the kinematics equations of the screw, roller and nut, the relative slipping speed of the contact point between the screw and the roller, the roller and the nut is solved, and the relative slippage of the contact point of the planetary roller screw is obtained. Transmission efficiency calculation formula. According to the technical requirements of this topic, the actual calculation of the key parameters of the thread of the planetary roller screw was performed.

The contact between the roller and the nut and screw in the planetary roller screw was briefly introduced. The spiral equation and the normal equation of the screw and roller in the planetary roller screw were solved. The numerical method is used to solve the actual contact point coordinates of the cross thread between the screw and the roller, and the screw thread is modified according to the calculation result. The section design of the roller thread diameter was calculated and numerically simulated. It was found that when the planetary roller screw was subjected to a rated axial static load of 100 kN, the bearing capacity of the planetary roller screw was greatly improved.

The load distribution of the screw contact points of the planetary roller screw was solved and numerical simulation analysis was performed. It was found that the axial forces borne by the roller were mainly distributed on the first few thread contact points on the side of the bearing end. Then calculate the axial deformation of the planetary

roller screw when the static load is 100kN, and get the axial static stiffness and Hertz contact stress of the screw contact point of the planetary roller screw. The influence of pitch and roller thread length on the bearing capacity of the planetary roller screw was analyzed. It was found that by increasing the pitch or changing the effective contact length of the roller thread, the bearing capacity of the planetary roller screw could not be significantly improved.

Based on GUI, MATLAB is used as a development platform to develop an integrated design and manufacturing simulation system for planetary roller screws integrating design, performance simulation, machining tool design and parameter measurement, including basic geometric parameters design, statics simulation, and measurement. The four system modules of parameter design and calculation and tool design can realize the rapid and accurate parameterized design and manufacture of planetary roller screw pairs, ensuring planetary roller screw transmission efficiency and bearing capacity.

Keywords:planetary roller screw;parameter design;repair design;static mechanical property analysis; development of simulation system