CN114060486B - External circulation ball screw and its return pipe structure - Google Patents

Abstract

The invention discloses an external circulation ball screw and a return pipe structure thereof. The screw cap is sleeved on the screw rod and provided with a plurality of spiral grooves, and one side surface of the screw cap is provided with a reflux channel communicated with the spiral grooves. The return pipe structure comprises an inner housing seat arranged on the return passage and an outer housing seat combined on the inner housing seat. The shell seat is provided with an outer reflux groove and a pair of outer positioning blocks arranged at two ends of the outer reflux groove, each outer positioning block stretches into the reflux channel and is communicated with the spiral groove, each outer positioning block is provided with a guide joint surface, and the guide joint surface extends from the inner wall surface of the outer reflux groove and is formed with a sharp tail end to be connected with the arc-shaped inner wall surface of the spiral groove; thereby, the balls of the external circulation ball screw are smoother in the circulation movement process.

Description

External circulation ball screw and its return pipe structure

Technical Field

The invention relates to a ball screw, and in particular to an external circulation ball screw and a return pipe structure thereof.

Background technique

The traditional external circulation ball screw is composed of a screw, a nut, a ball and a return pipe. The nut is set on the screw, the return pipe is installed on the outside of the nut, and finally the ball is set in the screw and the nut; thereby, the ball will enter the curved pipe from the spiral groove of the nut, and then return to the spiral groove through the return pipe to perform an infinite circulation motion.

Furthermore, the return pipe of the known external circulation ball screw is mostly formed by plastic integral injection molding or by upper and lower half return housings, and the two ends of the return pipe are connected to the load path formed by the screw and the nut to form a circulation path. However, the existing return pipe structure needs to be chamfered on the nut to accommodate the return housing that extends into the nut; however, there is often a tolerance between the chamfer and the return housing to form a step difference surface, which will cause the ball to be blocked during the circulation process, thereby affecting the smoothness of the circulation and needs to be improved.

In view of this, the inventor has devoted himself to studying the above-mentioned prior art and has applied the theory to try his best to solve the above-mentioned problems, which has become the research motivation of the inventor.

Summary of the invention

An object of the present invention is to provide a return pipe structure of an external circulation ball screw, so that the balls of the external circulation ball screw can move more smoothly during the circulation motion.

One object of the present invention is to provide a return pipe structure of an external circulation ball screw, wherein the outer shell seat and the nut have a larger combination tolerance in combination, thereby improving the yield of the nut and the return pipe structure.

In order to achieve the above-mentioned purpose, the present invention is a reflux pipe structure of an external circulation ball screw, which is used to be combined on a screw with a nut. The nut has a spiral groove and a reflux channel connected to the spiral groove, and the reflux pipe structure includes an inner shell seat and an outer shell seat. The inner shell seat is arranged on the reflux channel. The outer shell seat is correspondingly combined with the inner shell seat, and the outer shell seat has an outer reflux groove and a pair of outer positioning blocks arranged at both ends of the outer reflux groove. Each outer positioning block extends into the reflux channel and connects the spiral groove. Each outer positioning block has a guide surface, which extends from the inner wall surface of the outer reflux groove and is formed with a pointed end to connect with the arc-shaped inner wall surface of the spiral groove.

In order to achieve the above-mentioned purpose, the present invention is an external circulation ball screw, including a screw, a nut and a return pipe structure. The nut is sleeved on the screw, and the nut has a plurality of spiral grooves and a return channel connected to the spiral grooves is provided on one side. The return pipe structure includes an inner shell seat and an outer shell seat. The inner shell seat is arranged on the return channel. The outer shell seat is correspondingly combined with the inner shell seat, and the outer shell seat has an external return groove and a pair of external positioning blocks arranged at the two ends of the external return groove. Each external positioning block extends into the return channel and connects the spiral groove. Each external positioning block has a guide surface, which extends from the inner wall surface of the external return groove and is formed with a pointed end to connect the arc-shaped inner wall surface of the spiral groove.

Compared with the known, the outer shell seat of the return pipe structure of the external circulation ball screw of the present invention has an external return groove and a pair of external positioning blocks, each of which has a guiding surface and is formed with a pointed end to connect with the arcuate inner wall surface of the spiral groove; accordingly, the outer shell seat is in contact with the arcuate inner wall surface of the spiral groove through the guiding surface and its pointed end, thereby eliminating the traditional procedure of setting a chamfer on the inner wall surface of the nut and requiring secondary processing, and making the outer shell seat and the spiral groove continuously connected without the occurrence of a step surface, providing the ball with smooth rolling during the circulation process; in addition, the present invention can provide the outer shell seat and the nut with a larger combined tolerance in combination through the setting of the pointed end, thereby improving the yield of the nut and the return pipe structure and increasing the practicality of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective exploded schematic diagram of an external circulation ball screw of the present invention;

FIG2 is a perspective exploded schematic diagram of a reflux pipe structure of the present invention;

FIG3A is a cross-sectional view of a nut of the present invention;

FIG3B is a planar exploded view of the return pipe structure of the present invention;

FIG4 is a schematic diagram of the combination of the housing seat and the nut of the present invention;

FIG5 is a cross-sectional view of the combination of the housing seat and the nut of the present invention;

FIG6 is a partial cross-sectional view of the nut and reflux pipe structure of the present invention;

FIG7 is a combined cross-sectional view of the outer circulation ball screw and the return pipe structure of the present invention;

FIG. 8 is a partial enlarged schematic diagram of FIG. 7 .

Explanation of symbols in the accompanying drawings:

1: External circulation ball screw;

10: screw;

11: shaft;

20: Nut;

21: reflux channel;

22: spiral groove;

23: Mounting hole;

230: bevel;

30: reflux pipe structure;

40: inner shell seat;

41: internal reflow groove;

411: positioning bump;

42: internal positioning block;

420: oblique profile;

50: housing seat;

501: plane;

51: external reflux tank;

511: positioning groove;

52: external positioning block;

520: oblique profile;

521: guide surface;

522: pointed end;

523: Notch.

Detailed ways

The detailed description and technical contents of the present invention are described as follows with reference to the accompanying drawings. However, the accompanying drawings are only provided for reference and description and are not intended to limit the present invention.

Please refer to Figures 1 and 2, which are respectively a three-dimensional exploded schematic diagram of the external circulation ball screw of the present invention and a three-dimensional exploded schematic diagram of the return pipe structure. The present invention is an external circulation ball screw 1, comprising a screw 10, a nut 20 and a return pipe structure 30. The nut 20 is sleeved on the screw 10, and the return pipe structure 30 is assembled on the screw 10 sleeved with the nut 20, thereby forming the return pipe structure of the external circulation ball screw 1. The structure of the external circulation ball screw 1 is described in more detail as follows.

As shown in Fig. 1, the screw rod 10 has a shaft 11. The nut 20 is sleeved on the screw rod 10, and the inner wall of the nut 20 is formed with a plurality of spiral grooves 22 facing the shaft 11 and a reflux channel 21 communicating with the spiral grooves 22 is provided on one side.

Furthermore, the reflux pipe structure 30 is combined with the reflux channel 21 of the nut 20, and includes an inner shell seat 40 and an outer shell seat 50. The inner shell seat 40 and the outer shell seat 50 are positioned and covered with each other and assembled on the reflux channel 21 of the nut 20.

The inner shell seat 40 is disposed on the reflux channel 21. Specifically, the inner shell seat 40 has an inner reflux groove 41 and a pair of inner positioning blocks 42 disposed at two ends of the inner reflux groove 41. In this embodiment, the inner reflux groove 41 extends to the inner positioning blocks 42 at two ends.

Furthermore, the outer shell seat 50 is correspondingly combined with the inner shell seat 40. The outer shell seat 50 has an outer reflux groove 51 and a pair of outer positioning blocks 52 arranged at two ends of the outer reflux groove 51. Each of the outer positioning blocks 52 extends into the reflux channel 21 and communicates with the spiral grooves 22. Preferably, the outer reflux groove 51 extends to each of the outer positioning blocks 52 at two ends. In addition, the outer shell seat 50 has a plane 501 on a side away from the outer reflux groove 51, but this is not limited to the actual implementation.

In more detail, the outer housing 50 is formed with a plurality of positioning grooves 511 on both sides of the outer reflux groove 51. In addition, the inner housing 40 is formed with a plurality of positioning protrusions 411 on a side facing the outer housing 50. The inner housing 40 is positioned on the outer housing 50 by the positioning protrusions 411 being locked in the positioning grooves 511.

Please continue to refer to Figures 3A and 3B, which are respectively a cross-sectional view of the nut of the present invention and a planar exploded view of the reflux pipe structure. As shown in Figure 3A, in the present embodiment, the spiral groove 22 has two mounting holes 23 corresponding to the reflux channel 21 (see Figure 1), and each of the mounting holes 23 is used to accommodate part of the inner shell seat 40 and the outer shell seat 50. The inner positioning blocks 42 and the outer positioning blocks 52 extend into the two mounting holes 23 accordingly. Preferably, each of the mounting holes 23 has two opposite bevels 230. In addition, please refer to Figure 3B, in the present embodiment, each of the inner positioning blocks 42 is formed with two opposite oblique profiles 420 corresponding to each of the mounting holes 23; and each of the outer positioning blocks 52 is formed with two opposite oblique profiles 520 corresponding to each of the mounting holes 23.

It should be noted that the setting of the bevel 230 of the aforementioned mounting hole 23 allows the return pipe structure 30 to be applied to screws 10 of various sizes, or the nut 20 can be combined with a variety of different forms of return pipe structures 30, thereby reducing mold development costs and reducing costs, and increasing the flexibility of the return pipe structure 30 in setting.

Please refer to Figures 4 and 5, which are respectively a schematic diagram and a cross-sectional view of the combination of the housing seat and the nut of the present invention. As shown in the figure, in this embodiment, the housing seat 50 is combined in the reflux channel 21 of the nut 20, and the housing seat 50 has an outer reflux groove 51 and a pair of outer positioning blocks 52.

Specifically, each of the outer positioning blocks 52 has a guide surface 521, and the guide surface 521 extends from the inner wall surface of the outer return groove 51 and is formed with a pointed end 522 to connect with the arc-shaped inner wall surfaces of the spiral grooves 22. Accordingly, the outer housing 50 is attached to the arc-shaped inner wall surfaces of the spiral grooves 22 through the guide surface 521 and its pointed end 522.

It should be noted that, in this embodiment, the pointed end 522 of each of the outer positioning blocks 52 is a pointed cone, and each of the outer positioning blocks 52 is formed with a notch 523 , and both sides of the notch 523 have a pointed end 522 .

Please refer to Figures 6 to 8, which are a partial cross-sectional view, a combined cross-sectional view and a partial enlarged schematic view of the outer circulation ball screw and the return pipe structure of the present invention. As shown in Figure 6, the inner shell seat 40 and the outer shell seat 50 of the present invention can be assembled aside and then assembled onto the nut 20, or the inner shell seat 40 can be assembled into the nut 20 first and then the outer shell seat 50 can be positioned on the inner shell seat 40.

7 and 8, after the housing seat 50 is coupled to the nut 20, the guide surface 521 and the tip end 522 of the housing seat 50 will abut against the arcuate inner wall surfaces of the spiral grooves 22. Thus, the nut 20 and the tip end 522 are linearly adjacent to each other, so that the housing seat 50 and the spiral grooves 22 are continuously connected without a step difference surface, so that the ball can keep rolling smoothly during the circulation process.

Furthermore, the present invention can provide the housing seat 50 and the nut 20 with a larger combination tolerance in combination through the provision of the pointed end 522, and improve the yield of the nut 20 and the return pipe structure 30, thereby increasing the practicality of the present invention.

The above description is only a preferred embodiment of the present invention and is not intended to define the patent scope of the present invention. Other equivalent changes that apply the patent spirit of the present invention should all fall within the patent scope of the present invention.

Claims (5)

1. A reflux pipe structure of an external circulation ball screw, characterized in that it is used to be assembled on a screw sleeved with a nut, the nut having a spiral groove and a reflux channel connected to the spiral groove, and the reflux pipe structure comprises: an inner shell seat, disposed on the return channel; and An outer shell seat, correspondingly combined with the inner shell seat, the outer shell seat has an outer reflux groove and a pair of outer positioning blocks arranged at two ends of the outer reflux groove, each of the outer positioning blocks extends into the reflux channel and communicates with the spiral groove, each of the outer positioning blocks has a guide surface, the guide surface extends from the inner wall surface of the outer reflux groove and is formed with a pointed end to connect with the arc-shaped inner wall surface of the spiral groove; The outer shell seat is formed with a plurality of positioning grooves on both sides of the outer reflux groove, and the inner shell seat is formed with a plurality of positioning protrusions on a side facing the outer shell seat. The inner shell seat is positioned on the outer shell seat by the positioning protrusions being locked in the positioning grooves. The nut has two mounting holes capable of accommodating part of the inner shell seat and the outer shell seat, and each of the mounting holes has two opposite bevels. The inner shell seat has an inner reflow groove and a pair of inner positioning blocks arranged at two ends of the inner reflow groove, and the outer reflow groove covers the inner reflow groove; Each of the inner positioning blocks and each of the outer positioning blocks is formed with two opposite oblique edges corresponding to each of the mounting holes. 2. The reflux pipe structure of the external circulation ball screw as described in claim 1 is characterized in that the inner reflux groove extends to each of the inner positioning blocks at two ends; and the outer reflux groove extends to each of the outer positioning blocks at two ends. 3. The return pipe structure of the external circulation ball screw as described in claim 1 is characterized in that the nut and the pointed end are adjacent to each other in a straight line. 4. The return pipe structure of the external circulation ball screw as described in claim 1 is characterized in that the tip end of each external positioning block is a pointed cone, and each external positioning block is formed with a recess, and the two sides of the recess respectively have a pointed end. 5. An external circulation ball screw, characterized by comprising: A screw; a nut, sleeved on the screw rod, the nut having a plurality of spiral grooves and a reflux channel connected to the spiral grooves on one side; and A return pipe structure according to any one of claims 1 to 4, wherein the return pipe structure is combined with the return channel; The nut has two mounting holes capable of accommodating part of the inner shell seat and the outer shell seat, each mounting hole has two opposite bevels, and each inner positioning block and each outer positioning block are respectively formed with two opposite bevels corresponding to each mounting hole.