A differential planetary roller screw nut annular groove plastic forming device and process

Abstract

A differential planetary roller screw nut annular groove plastic forming device and process, the device includes an eccentric system and a rolling system, the eccentric system is composed of a bracket, a wedge block and a slider, the bracket is connected with a wedge block, the wedge block above A slider is connected to the bracket; the rolling system includes a support shaft, a sliding bearing, a rolling mold and a retaining ring, one end of the supporting shaft is fixedly connected with the slider, a sliding bearing is installed on the supporting shaft, and a rolling bearing is installed on the sliding bearing. The axial direction of the die, the sliding bearing and the rolling die is positioned through the shoulder of the supporting shaft and the retaining ring; the process is to clamp the workpiece first to ensure that the axis of the workpiece coincides with the axis of the rolling die; then the workpiece or the rolling die is sent axially Advance, the wedge block moves in the axial direction, the workpiece rotates, and the annular groove on the inner surface of the nut is formed; the wedge block moves back in the axial direction, the slider moves downward, and the material is unloaded; the invention can reduce material waste, improve processing efficiency and anti-fatigue of parts performance and surface quality.

Description

technical field [0001] The invention belongs to the technical field of advanced material forming and manufacturing, and in particular relates to a differential planetary roller screw nut annular groove plastic forming device and process. Background technique [0002] In 1942, the Swedes invented the planetary roller screw pair, and the planetary roller screw has been widely recognized and applied for its high load, impact resistance, high precision and many other advantages. However, the structure of the roller screw is complex, and the requirements for machining accuracy are high, especially the roller structure includes a thread and a gear structure. In 1993, the German Aerospace Center developed the PWG differential planetary roller screw. The PWG differential planetary roller screw is based on the principle of the planetary roller screw and combines planetary transmission and screw transmission. Nuts, screws, rollers All are annular groove structures. [0003] However,...

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Problems solved by technology

[0003] However, at present, the cutting process is generally used in the inner ring groove of the nut, which causes waste of materials and has the problem of low efficiency; at the same time, the cutting process cuts off the metal fiber, which reduces the strength of the material and reduces the fatigue resistance of the parts.

[0004] In terms of plastic forming of the inner surface of the workpiece, the axial feed rolling forming process can be used for internal threads with large inner diameters (Shuowen Zhang, Dawei Zhang, Yongfei Wang, et al. The planetary rolling process of forming the internal thread. International Journal of Advanced Manufacturing Technology,2020,107:3543-3551.), the structure of the inner annular groove of the PWG differential planetary roller screw nut is similar to that of the internal thread, but the inner ring groove of the PWG differential planetary roller screw nut The annular groove has no lead angle and cannot be formed by axial rolling; in addition, the diameter of the annular groove nut in the PWG differential planetary roller screw nut is usually small, requiring a very small diameter of the rolling die, which It will increase the difficulty of thread rolling wheel manufacturing while reducing the rigidity of the mold support shaft and reduce the precision of nut manufacturing

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