Cover type ball screw with double nut preload structure

Abstract

The invention discloses an end cover type ball screw with a double-nut pre-pressing structure. The end cover type ball screw comprises a long shaft, two nuts, four end covers and two pre-pressing pieces. Each of the nut is provided with a through hole allowing the long shaft to penetrate. The four end covers are respectively disposed on the two end faces of the two nuts. Each pre-pressing piece is provided with a mounting hole allowing the long shaft to penetrate. The axial direction of the each pre-pressing piece is provided with two end faces, one end face is provided a plurality of protruding columns, and the other end face is a plane. The planes of the two pre-pressing pieces are fitted to each other. The protruding columns penetrate to the end covers. The end faces of the protruding columns are in contact with the end faces of the nuts. By the structure, the double nuts can be adjusted conveniently for pre-pressing, the service life of the ball screw is further prolonged, and the positioning accuracy and rigidity of the ball screw are further increased.

Description

technical field [0001] The invention relates to a transmission assembly, in particular to an end cover type ball screw with double nut preloading structure. Background technique [0002] For example, China Taiwan Patent No. 201018812 discloses an end cap type ball screw, which includes: a screw with thread grooves on its outer periphery; a nut with inner holes running through both ends of the inner holes. There is a threaded groove, so that the threaded groove and the threaded groove are combined to form a load path; the nut is provided with two holes on both ends, and the surface of the nut is concentrically provided with a larger diameter on the edge of the hole. Assembly groove; two circulation end caps are respectively fixed on the two ends of the nut, which have an inner hole for the screw to pass through, and the end cap is provided with a return channel. The load channel, the return channel and the hole are matched to form a closed channel, so that the ball Through t...

AI Technical Summary

Problems solved by technology

[0003] The characteristic of this type of end cap ball screw is: it has a high lead, and the distance traveled by the nut after one rotation of the screw is large; it has multiple threads to increase its load; therefore, it is often used in transmission and high-feed industries, but it is the only one The disadvantage is that it cannot be combined with the preloading structure of the double nut type, and the preloading structure with double nuts will further improve the life, positioning accuracy and rigidity of the ball screw, and these functions are often the most concerned by users. The reason why the end cap type ball screw cannot make the preload structure of the double nut is that the preload structure of the double nut needs to be provided with a preload piece between the two nuts, so that the two nuts face the shafts in the same direction or in different directions. direction displacement, so that the balls in the two nuts are in two-point contact with the rolling groove and the groove, but because the end caps of the end cap type ball screw are installed on both ends of the nut, the pre-compression piece must be installed on both ends of the cap Between and in contact with the two end caps, and the end caps are provided with multiple return channels and meat escape parts (most end caps are all made of plastic injection molding, in order to prevent deformation after injection, multiple meat escape parts are set to allow the meat to The thickness is equal), so the end cover can be said to be a thin shell, and its strength is very low, so it cannot withstand the axial force generated when the preload of the two nuts is adjusted by the preloader. Often the two ends The cover thus ruptures or deforms the return channel, causing the balls to fail to circulate

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