A Roller of Planetary Roller Screw Pair for Improving Roller Force

Abstract

A roller of a planetary roller screw pair for improving roller stress comprises gear section structures at the two ends and a middle thread section structure. The gear section structures at the two ends are helical tooth-shaped structures. For a standard planetary roller screw, the radius of addendum circles of the gear section structures at the two ends of the roller is reduced, the gear sectionstructures at the two ends are not in physical contact with a first lead screw, and the transmission ratio i of a roller gear to an inner gear ring accords with the kinematic relation of the roller, the first lead screw and a first nut of the planetary roller screw. In the same way, in a reverse planetary roller screw, the radius of addendum circles of the gear section structures at the two ends is reduced, the gear section structures at the two ends are not in physical contact with an internal thread of a second nut, and the transmission ratio i of a roller gear to a gear ring accords with the kinematic relation of the roller, a second lead screw and the second nut in the planetary roller screw. According to the roller, helical teeth at the two ends of the roller are only engaged with helical inner gear rings on the nuts or holder helical gears at the two ends of a short lead screw to do planetary motion, the axial force and axial deformation of the roller are reduced, the structure is simplified, and synchronous rolling forming is convenient.

Description

technical field [0001] The invention belongs to the technical field of mechanical transmission, and in particular relates to a roller of a planetary roller screw pair for improving the force on the roller. Background technique [0002] There are two types of traditional planetary roller screw structures: standard type and reverse type. The standard type planetary roller screw has a long screw and short nut structure, and there is no axial relative movement between the roller and the nut; reverse type The planetary roller screw has a short screw and long nut structure, and there is no axial relative movement between the roller and the screw. The standard and reverse planetary roller screws are mainly composed of a screw, a nut and many rollers. The roller structure is divided into a middle thread section and two end gear sections: the middle thread section, the screw thread section and the thread of the nut. The gear segments at both ends are in contact with each other to tr...

AI Technical Summary

Problems solved by technology

The standard and reverse planetary roller screws are mainly composed of a screw, a nut and many rollers. The roller structure is divided into a middle thread section and two end gear sections: the middle thread section, the screw thread section and the thread of the nut. The gear segments at both ends are in contact with each other to transmit power and bear the load; the gear segments at both ends mesh with the inner ring gear of the standard planetary roller screw pair or the gear ring of the reverse planetary roller screw pair to reduce the sliding of each roller , to maintain the consistency of planetary motion, and in addition, it needs to be in contact with the lead screw; the gear segments at both ends of the roller mesh with the inner ring gear of the standard planetary roller screw pair or the gear ring of the reverse planetary roller screw pair The degree of overlap affects the stability of the transmission system; in addition, during the transmission process, the axial force generated by the roller due to the load has axial deformation and Hertzian contact deformation, which affects the force on the roller and the transmission accuracy.

[0003] There are gears and threads at both ends of the planetary roller screw roller. At present, the cutting process is used, which has low efficiency and serious material waste; in addition, the threads are generally cut first, and then the tooth profile is processed. Among the rod rollers, there are special requirements for the phase of the thread and the gear segment. The rollers of the same planetary roller screw pair must be exactly the same, and the phase consistency between the gear and the thread must be ensured during processing, but it is difficult to ensure the phase of the roller by cutting. Phase consistency between columns requires additional tooling to ensure phase accuracy and increase manufacturing cycle

[0004] In Chinese patent ZL201310034355.8, a new processing method for synchronous rolling forming of shaft parts with thread and gear characteristics is proposed. Using the corresponding mold, one-time rolling forming of shaft parts with thread and gear can improve manufacturing efficiency and ensure thread The phase accuracy with the gear, but the original planetary roller screw roller has a special complex structure of gears and threads at both ends of the roller, which is not conducive to synchronous rolling and forming rollers

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