External-circulation ball screw

Abstract

An external-circulation ball screw comprises a screw body and a nut. The screw body is provided with a first rolling groove, the nut is provided with a second rolling groove, a circulating component comprises a first foot portion, a second foot portion and a connecting portion, the first foot portion is provided with a first inner end point and a first outer end point which are on a first end face, the second foot portion is provided with a second inner end point and a second outer end point which are on a second end face, a circulating passage forms a first inlet-outlet and a second inlet-outlet on the first end face and the second end face, first thickness is spaced between the first inlet-outlet and the first inner end point, second thickness is spaced between the first inlet-outlet and the first outer end point, the second thickness is more than three times of the first thickness, third thickness is spaced between the second inlet-outlet and the second inner end point, fourth thickness is spaced between the second inlet-outlet and the second outer end point, and the fourth thickness is more than three times of the third thickness. Consequently, the circumstance that a groove wall of the second rolling groove is occupied is reduced, and probability that a thread of the nut is damaged is lowered.

Description

technical field [0001] The present invention relates to a ball screw, in particular to an external circulation ball screw. Background technique [0002] By the way, the ball screw plays a very important role in the field of linear transmission. The balls set in it reduce the friction between the screw and the nut, so that the screw and the nut can move relative to each other quickly and accurately. [0003] As the mechanical structure becomes more and more refined, the volume of the ball screw also needs to be reduced due to the limited space of the application. Among many ball screw products, the external circulation ball screw is quite suitable for use in small space applications. Such as Figure 1-Figure 3 As shown, the circulating tube type ball screw apparatus includes a screw 1 with a spiral first rolling groove 2 on its surface and a nut 3 with a perforation 4 through which the perforation 4 is sleeved The screw 1 and the nut have a helical second rolling groove 5 o...

AI Technical Summary

Problems solved by technology

[0004] like figure 2 As shown, however, in the above-mentioned tubular external circulation ball screw, the circulation pipe 7 passes through the nut 3 and communicates with the load path, and the pipe wall of the circulation pipe 7 occupies part of the second rolling groove 5 in the effective tooth area in the nut 3 The position of the groove wall makes the groove wall thinner, which is easy to give way to the second rolling groove 5 in the effective tooth area. The groove wall collapses and causes the problem of nut broken teeth

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