TWI754336B - External circulation ball screw and return pipe structure thereof - Google Patents

Abstract

The invention is an external circulation ball screw including a screw, a nut and a return pipe structure. The nut is combined with the screw and has a plurality of spiral grooves, and one side of the nut is provided with a return channel communicated with the spiral grooves. The return pipe structure includes an inner shell seat arranged on the return channel and an outer shell seat combined on the inner shell seat. The outer shell seat has an external return groove and a pair of outer positioning blocks arranged at two ends of the external return groove. Each outer positioning block extends into the return channel and communicates with the spiral grooves, and each outer positioning block has a guiding surface extended from the inner wall surface of the external return groove and is formed with a pointed end to connect with the arc-shaped inner wall surface of the spiral grooves. Thus, the balls in the external circulation ball screw will be moved more smoothly in the process of circulating movement.

Description

External circulation ball screw and its return pipe structure

The present invention relates to a ball screw, especially a structure of an external circulation ball screw.

The traditional external circulation ball screw is composed of a screw, a nut, a ball and a return pipe. In the screw and the nut; thereby, the balls will enter the elbow from the helical groove of the nut, and then return to the helical groove through the return pipe to make an infinite circular motion.

In addition, most of the return pipes of the conventional external circulation ball screw are made of plastic integral injection molding or composed of upper and lower semi-return shells, and the two ends of the return pipe are connected to the load formed by the screw and the nut. The paths are connected to form a circular path. However, in the existing structure of the return pipe, a chamfer needs to be provided on the nut to accommodate the return housing that extends into the nut; however, there is often a tolerance in the assembly between the chamfer and the return housing, which results in a fracture. The difference surface will cause the ball to be blocked during the cycle, which will affect the smoothness of the cycle and needs to be improved.

In view of this, the inventor of the present invention has devoted himself to the research on the above-mentioned prior art and cooperated with the application of theories, and tried his best to solve the above-mentioned problems, which is the research motivation of the present inventor.

One of the objectives of the present invention is to provide a return pipe structure of the external circulation ball screw, so that the balls of the external circulation ball screw can be more smoothly in the process of circulating movement.

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 large combined tolerance on the 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 return pipe structure of an external circulation ball screw, which is used to be assembled on a screw sleeve with a nut. The nut has a spiral groove and a return channel communicating with the spiral groove, and the return pipe structure includes an inner shell seat and an outer shell seat. The inner housing seat is arranged on the return channel. The outer shell seat is correspondingly combined with the inner shell seat. The outer shell seat has an outer return groove and a pair of outer positioning blocks arranged at both ends of the outer return groove. Each outer positioning block extends into the return channel and communicates with the spiral groove. Each outer positioning block has a guide surface , the guide surface extends from the inner wall surface of the outer reflow 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 helical grooves and a return channel which communicates with the helical grooves is arranged on one side. The return pipe structure includes an inner shell seat and an outer shell seat. The inner housing seat is arranged on the return channel. The outer shell seat is correspondingly combined with the inner shell seat. The outer shell seat has an outer return groove and a pair of outer positioning blocks arranged at both ends of the outer return groove. Each outer positioning block extends into the return channel and communicates with the spiral groove. Each outer positioning block has a guide surface , the guide surface extends from the inner wall surface of the outer reflow groove and is formed with a pointed end to connect with the arc-shaped inner wall surface of the spiral groove.

Compared with the prior art, the outer shell seat of the return pipe structure of the external recirculating ball screw of the present invention has an external return groove and a pair of external positioning blocks. According to this, the housing seat is attached to the helical groove through the guide surface and its pointed end. The arc-shaped inner wall avoids the need for secondary processing of the traditional chamfering on the inner wall of the nut, and makes the shell seat and the helical groove connect continuously without a section surface, providing the balls in the circulation. During the process, smooth rolling is maintained; in addition, the present invention can provide the housing seat and the nut with a large combined tolerance on the combination through the arrangement of the pointed end, so as to improve the yield rate of the nut and the return pipe structure, and increase the practicability of the present invention .

1: External circulation ball screw

10: Screw

11: Shaft

20: Nut

21: Return channel

22: Spiral groove

23: Mounting holes

230: hypotenuse

30: return pipe structure

40: Inner shell seat

41: Internal reflow tank

411: Positioning bump

42: Internal positioning block

420: Oblique profile

50: Shell seat

501: Flat

51: External reflow tank

511: Positioning slot

52: External positioning block

520: Oblique profile

521: Conductor surface

522: tip end

523: Notch

Fig. 1 is a perspective exploded schematic view of a recirculating ball screw outside the present invention.

FIG. 2 is a perspective exploded schematic view of the structure of the return pipe of the present invention.

3A is a cross-sectional view of the nut of the present invention.

3B is an exploded plan view of the structure of the return pipe of the present invention, respectively.

FIG. 4 is a schematic diagram of the combination of the housing base and the nut of the present invention.

FIG. 5 is a cross-sectional view of the combination of the housing base and the nut of the present invention.

6 is a partial cross-sectional view of the structure of the nut and the return pipe of the present invention.

FIG. 7 is a combined cross-sectional view of the structure of the circulating ball screw and the return pipe outside the present invention.

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

The detailed description and technical content of the present invention are described below in conjunction with the drawings. However, the accompanying drawings are only for reference and description, and are not intended to limit the present invention.

Please refer to FIG. 1 and FIG. 2 , which are a perspective exploded schematic diagram of a recirculating ball screw outside the present invention and a perspective exploded schematic diagram of the structure of the return pipe, respectively. The present invention is an external circulation ball screw 1, including It includes 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 , so as to constitute the return pipe structure of the outer circulating ball screw 1 . The structure of the external circulation ball screw 1 will be described in more detail as follows.

As shown in FIG. 1 , the screw 10 has a shaft 11 . In addition, the nut 20 is sleeved on the screw 10, the inner wall of the nut 20 is formed with a plurality of helical grooves 22 on the corresponding shaft 11, and a backflow connecting the helical grooves 22 is formed on one side of the nut 20 Channel 21.

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

The inner housing 40 is arranged on the return channel 21 . Specifically, the inner housing 40 has an inner return groove 41 and a pair of inner positioning blocks 42 disposed at both ends of the inner return groove 41 . In this embodiment, the inner return groove 41 extends to the inner positioning blocks 42 at both ends.

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

In more detail, the housing seat 50 is formed with a plurality of positioning grooves 511 on two sides of the outer return groove 51 . In addition, a plurality of positioning protrusions 411 are formed on a side of the inner housing 40 facing the outer housing 50 . The inner housing 40 is positioned on the outer housing 50 through the positioning protrusions 411 being clamped in the positioning grooves 511 .

Please continue to refer to FIG. 3A and FIG. 3B , which are a cross-sectional view of the nut and an exploded plan view of the return pipe structure of the present invention, respectively. As shown in FIG. 3A , in this embodiment, the helical groove 22 has two mounting holes 23 corresponding to the return channel 21 (see FIG. 1 ), and each of the mounting holes 23 is used for accommodating part of the inner housing seat 40 and the outer housing Seat 50. The pair of inner positioning blocks 42 and the outer positioning blocks 52 extend into the two mounting holes 23 correspondingly. Preferably, each of the mounting holes 23 has two opposite oblique sides 230 . In addition, please refer to FIG. 3B , in this embodiment, each of the inner positioning blocks 42 is formed with two opposite oblique contours 420 corresponding to each of the installation holes 23 ; and each of the outer positioning blocks 52 is formed with corresponding to each of the installation holes 23 . Opposite bi-inclined profile 520 .

It should be noted that, the arrangement of the oblique edge 230 of the mounting hole 23 can provide the return pipe structure 30 to be applied to screws 10 of various sizes, or the nut 20 can be combined with various types of return pipe structures 30, thereby reducing the The cost of mold development is reduced, and the flexibility of the arrangement of the return pipe structure 30 is increased.

Please refer to FIG. 4 and FIG. 5 , which are a schematic diagram and a cross-sectional view of the combination of the housing base and the nut of the present invention, respectively. As shown in the figure, in this embodiment, the outer shell seat 50 is combined in the return channel 21 of the nut 20 , and the outer shell seat 50 has an outer return 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 spiral grooves 22 Arc inner wall. Accordingly, the outer housing 50 is attached to the arcuate inner wall surfaces of the spiral grooves 22 through the guiding surface 521 and the tip end 522 thereof.

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 recess 523, and two sides of the recess 523 respectively have a pointed end 522.

Please also refer to FIGS. 6 to 8 , which are respectively a partial cross-sectional view, a combined cross-sectional view and a partial enlarged schematic view of the structure of the circulating ball screw and the return pipe outside the present invention. As shown in FIG. 6 , the inner housing 40 and the outer housing 50 of the present invention can be assembled on one side and then assembled to the nut 20 , or the inner housing 40 can be assembled into the nut 20 first The outer housing 50 is then positioned on the inner housing 40 .

7 and FIG. 8 , in the present invention, after the housing seat 50 is combined with the nut 20 , the guide surface 521 and the tip end 522 of the housing seat 50 will abut against the arcs of the spiral grooves 22 shaped inner wall. Accordingly, the nut 20 and the pointed end 522 are in a straight line adjoining, so that the housing seat 50 and the helical groove 22 are continuously connected without a broken surface, so that the ball can be circulated during the cycle. Keep scrolling smoothly.

In addition, the present invention can provide the housing seat 50 and the nut 20 with a larger assembly tolerance through the arrangement of the pointed end 522, and improve the yield of the nut 20 and the return pipe structure 30, thereby increasing the cost practicality of the invention.

The above descriptions are only preferred embodiments of the present invention and are not intended to define the patent scope of the present invention. Other equivalent changes using the patent spirit of the present invention shall all belong to the patent scope of the present invention.

1: External circulation ball screw

10: Screw

11: Shaft

20: Nut

22: Spiral groove

50: Shell seat

52: External positioning block

521: Conductor surface

522: tip end

Claims (10)

A return pipe structure of an external circulation ball screw is used to be assembled on a screw sleeve with a nut, the nut has a helical groove and a return passage communicating with the helical groove, and the return pipe structure includes: a The inner shell seat is arranged on the return channel; and an outer shell seat is correspondingly combined with the inner shell seat, and the outer shell seat has an outer return groove and a pair of outer positioning blocks arranged at both ends of the outer return groove, each of which is The outer positioning blocks extend into the return channel and communicate with the helical groove. Each of the outer positioning blocks has a guide surface, which extends from the inner wall surface of the outer return groove and is formed with a pointed end to connect with it. The arc-shaped inner wall surface of the spiral groove. The return pipe structure of an externally circulating ball screw according to claim 1, wherein the inner housing has an inner return groove and a pair of inner positioning blocks disposed at both ends of the inner return groove, and the outer return groove covers the inner return groove. return tank. The return pipe structure of an externally circulating ball screw according to claim 2, wherein the inner return groove extends to each of the inner positioning blocks at both ends; the outer return groove extends to each of the outer positioning blocks at both ends. The return pipe structure of an externally circulating ball screw according to claim 1, wherein the outer shell seat is formed with a plurality of positioning grooves on two sides of the outer return groove, and the inner shell seat is formed with a plurality of positioning grooves on a side facing the outer shell seat. The inner shell seat is positioned on the outer shell seat by being clamped in the positioning grooves by the positioning protrusions. The return pipe structure of the external circulating ball screw according to claim 4, wherein each of the inner positioning blocks and each of the outer positioning blocks are respectively formed with opposite two-inclined contours. The return pipe structure of the external circulating ball screw according to claim 1, wherein the nut and the tip end are in a straight line adjoining. The return pipe structure of an externally circulating ball screw according to claim 1, wherein the tip end of each of the external positioning blocks is a pointed cone, and each of the external positioning blocks is formed with a recess, and two sides of the recess are respectively provided with a pointed end. An external circulation ball screw, comprising: a screw; a nut sleeved on the screw, the nut has a plurality of helical grooves and a return channel connecting the helical grooves on one side; The return pipe structure according to any one of claims 1 to 7, which is combined with the return channel. The external recirculating ball screw according to claim 8, wherein the nut has two mounting holes for accommodating part of the inner housing seat and the outer housing seat, and each of the mounting holes has two opposite inclined edges. The external recirculating ball screw according to claim 9, wherein each of the inner positioning blocks and each of the outer positioning blocks are respectively formed with opposite two-inclined contours corresponding to each of the mounting holes.

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