JP2012154437A - Ball screw with circulating piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball screw with a circulating piece which can be applied to a nut with a smaller outer diameter and makes it unnecessary to adopt protruding teeth design.SOLUTION: The ball screw with a circulating piece includes: a screw shaft having an axis line and an external spiral groove spirally arranged around the axis line; the nut which is provided to engage with the screw shaft along the axis line with an internal spiral groove spirally arranged around the axis line and in which a load path for accommodating a number of balls, a circulating hole opening for free passage with the internal spiral groove, and an accommodation space arranged along the axis line from an end face of the nut are formed by the external spiral groove and the internal spiral groove; and a circulating piece which is arranged in the accommodation space along the axis line so as to be divided into a first circulating block and a second circulating block, the first circulating block including an upper surface and a first divided surface in the opposite direction to the upper surface and the second circulating block including a second divided surface forming a flat surface and coming closer to the first divided surface and a bottom surface forming a flat surface and coming closer to the groove bottom surface, wherein the bottom surface and the second divided surface form a certain open angle.

Description

The present invention relates to a ball screw, and more particularly to a ball screw with a rotator.

FIG. 1 is a cross-sectional view showing US Pat. No. 4,357,838 of Patent Document 1. As shown in FIG. This is a ball screw having a rotator, the rotator 11 is attached from the axial direction of the end face of the nut 12, and the rotator 11 has a claw 111. The claw 111 has a protruding state and is provided inside the outer spiral groove 131 of the screw shaft 13. The claw 111 connects the outer spiral groove 131 of the screw shaft 13 and the rotator 11. Each ball 14 enters the circulation hole (not shown) of the nut 12 by the guide of the flow rotator 11, so that the ball 14 between the screw shaft 13 and the nut 12 can be continuously circulated. The impact force caused by the convection can be eliminated. However, since the outer spiral groove 131 of the screw shaft 13 and the claw 111 of the rotator 11 are fitted to each other by unevenness, one end of both ends of the outer spiral groove 131 of the screw shaft 13 needs to be open. Yes (the industry refers to “protrusion design”). If it does so, it is necessary for the shoulder part of the screw shaft 13 to employ a protruding design. According to such a configuration, the life of the ball screw is shortened.

FIG. 2 is a cross-sectional view showing US 2008/0110284 A1 of Patent Document 2. As shown in FIG. This is a ball screw having a commutator, and the commutator is configured by combining a plurality of stages, that is, configured by combining the internal circuit block 16 and the external circuit block 17, whereby the screw shaft 18 protrudes. No need to adopt a design. However, since the upper surface 171 and the bottom surface 172 of the outer circulation block 17 are flat, parallel to each other, and do not form an opening angle, it is necessary to match the nut 19 having a larger outer diameter. , European Industrial Standard (DIN)) nuts were not applicable.

U.S. Pat. No. 4,357,838 US 2008/0110284 A1

A main object of the present invention is to provide a ball screw with a commutator that can be applied to a nut having a smaller outer diameter and does not need to employ a protruding design.

According to the ball screw with a commutator of the present invention, a screw shaft having an axis and an outer spiral groove provided spirally around the axis, and fitted to the screw shaft along the axis, the axis is An inner spiral groove provided in a spiral shape, and by the outer spiral groove and the inner spiral groove, a load path for accommodating a plurality of balls, a circulation hole communicating with the inner spiral groove, and an end surface of the nut An accommodation space provided along the axis, and the accommodation space includes a nut including a groove bottom surface corresponding to the outer spiral groove, and a groove wall surface penetrating the circulation hole, and the axis. The first dividing block is provided in the accommodating space along the axis and divided into a first circulating block and a second circulating block along the axis, and the first dividing block is in the direction opposite to the upper surface. And the second flow block Includes a second divided surface that is flat and close to the first divided surface, and a bottom surface that is flat and close to the bottom surface of the groove, and has an opening angle with the bottom surface and the second divided surface. And the maximum distance between the first divided surface and the top surface is HC1, the maximum distance between the second divided surface and the bottom surface is HC2, and a rotator with HC2 larger than HC1 is included. It is characterized by.

According to the ball screw with a commutator of the present invention, the opening angle is about 18 to 25 degrees.

According to the ball screw with a commutator of the present invention, a localization portion is provided on the first dividing surface of the first circulating block, and the localization facing the bottom surface is provided on the second dividing surface of the second circulating block. A recess is provided, and the localization portion is positioned by fitting with the localization recess.

According to the ball screw with a commutator of the present invention, the first circulation block is further provided with a first circulation passage provided on the first dividing surface and facing the upper surface, and a claw provided on the outer spiral groove. The second circulation block further includes a second circulation passage provided on the second dividing surface and facing the bottom surface, and the second circulation block includes the second circulation passage and the first circulation passage. A circulation path communicating with the circulation hole and the load path is formed.

According to the ball screw with a commutator of the present invention, both ends of the outer spiral groove of the screw shaft are closed.

According to the ball screw with a commutator of the present invention, it can be applied to a nut having a smaller outer diameter, and there is an effect that it is not necessary to employ a protruding design.

It is sectional drawing which shows U.S. Pat. No. 4,357,838. It is a schematic diagram which shows US Patent No. 2008/0110284 A1. It is an exploded perspective view of the present invention. It is a perspective view which shows the nut of this invention. It is a perspective view which shows the combined state of the circulating element of this invention. It is a disassembled perspective view of the circulating element of this invention. It is a side view which shows the combined state of the circulating element of this invention. It is a schematic diagram which shows the state in which the 1st circulation block of one Example of this invention is put along an axial direction. It is a schematic diagram which shows the state in which the 1st circulation block of one Example of this invention is put along a diameter direction. It is a schematic diagram which shows the state in which the 2nd circulation block of one Example of this invention is put along an axial direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, reference is made to FIGS. The ball screw with a rotator according to an embodiment of the present invention includes a screw shaft 20, a nut 30, and a rotator.

The screw shaft 20 includes an axis line 21 and an outer spiral groove 22 provided around the axis line 21 in a spiral shape. Both ends of the outer spiral groove 22 exhibit a closed state (that is, not adopting a protruding design) or an open state (that is, adopting a protruding design). In the present embodiment, both ends of the outer spiral groove 22 are in a closed state.

The nut 30 is fitted to the screw shaft 20 along the axis 21 and includes an inner spiral groove 31 provided around the axis 21 in a spiral shape. The inner spiral groove 31 and the outer spiral groove 22 are provided along the axis 21 from the end surface of the nut 30, the load path for accommodating a large number of balls 91, the circulation hole 32 communicating with the inner spiral groove 31, and the outer spiral groove 22. An accommodation space 33 corresponding to the spiral groove 22 and the circulation hole 32 is formed. The accommodation space 33 includes a groove bottom surface 331 corresponding to the outer spiral groove 22 and a groove wall surface 332 penetrating the circulation hole 32.

The commutator is provided in the accommodation space 33 of the nut 30 along the axis 21, and is divided into a first commutation block 40 and a second commutation block 50 along the axis 21. In other words, the surface close to the groove wall surface 332 of the accommodating space 33 of the rotator is a receiving surface, and there is an end surface in a direction opposite to the receiving surface. It is divided into a circulation block 40 and a second circulation block 50.

The first circulation block 40 includes an upper surface 41 and a first dividing surface 42 in the direction opposite to the upper surface 41. The second circulation block 50 includes a second divided surface 51 that is flat and approaches the first divided surface 42, and a bottom surface 52 that is flat and close to the groove bottom surface 331. The bottom surface 52 and the second dividing surface 51 form an opening angle, and the opening angle is about 18 to 25 degrees. The maximum distance between the first divided surface 42 and the upper surface 41 is HC1, the maximum distance between the second divided surface 51 and the bottom surface 52 is HC2, and HC2 is larger than HC1.

The bottom surface 52 of the second circulation block 50 is close to the groove bottom surface 331 of the accommodation space 33, and the second receptacle is close to the groove wall surface 332 of the accommodation space 33 between the second divided surface 51 and the bottom surface 52. A first receiving surface that is provided with a surface 53 and is located between the first divided surface 42 and the upper surface 41 of the first circulation block 40 and is located on a plane on which the second receiving surface 53 is positioned, and is close to the groove wall surface 332 43 is provided. The first receiving surface 43 and the second receiving surface 53 constitute a receiving surface for the rotator. The first circulation block 40 has a first end face 44 in the direction opposite to the first receiving surface 43. The second circulation block 50 has a second end surface 54 located in a plane opposite to the second receiving surface 43 and on which the first end surface 44 is located. The first end face 44 and the second end face 54 constitute an end face of the rotator.

A localization portion 45 is provided on the first dividing surface 42 of the first circulation block 40, and a localization recess 55 facing the bottom surface 52 is provided on the second division surface 51 of the second circulation block 50, and the localization portion 45 is It is positioned by fitting with the positioning recess 55. Of course, the method of fitting the stereotaxic portion 45 and the stereotaxic recess 55 is not limited to the above method, and any other fitting method may be adopted as long as the stereotaxic portion 45 and the stereotaxic recess 55 can be localized. .

The first circulation block 40 further includes a first circulation passage 46 provided on the first dividing surface 42 and facing the upper surface 41, and a claw 47 provided in the outer spiral groove 22 of the screw shaft 30. . The second circulation block 50 further includes a second circulation passage 56 provided on the second dividing surface 51 and facing the bottom surface 52. The second circulation path 56 and the first circulation path 46 form a circulation path 92 that communicates with the circulation hole 32 and the load path.

The second circulation block 50 further includes a lug 58. The lug 58 is provided with a lock hole 281. The screw 59 can be screwed into the nut 59 through the lock hole 281 of the lug 58.

Next, the ball screw assembling method of the present invention will be described with reference to FIG. First, the nut 30 is fitted on the screw shaft 20 and the divided first circulation block 40 is slightly displaced in the diametrical direction, so that the claw 47 does not interfere with the screw shaft 20 and the nut 30 extends along the axial direction. Can be placed in the storage space 33. As shown in FIG. 9, when the first receiving surface 43 of the first circulation block 40 is close to the groove wall surface 332 of the accommodation space 33, the first circulation block 40 is shifted to a certain angle in the diametric direction, thereby Is located inside the outer spiral groove 22 of the screw shaft 20. Next, as shown in FIG. 10, the second circulation block 50 is inserted into the accommodation space 33 of the nut 30 along the axial direction, and the localization recess 55 of the second circulation block 50 and the localization portion 45 of the first circulation block 40. Are fitted together and positioned, and finally, the lock hole 581 of the lug 58 of the second circulation block 50 and the nut 30 are fastened by the screw 59. If it does so, the said commutator can be fastened to the accommodation space 33 of the nut 30 stably. Since screw interference can be avoided by the above combination method, the screw shaft 20 of the present invention does not have to employ a protruding design.

The opening angle A between the bottom surface 52 of the second circulation block 50 and the second dividing surface 51 is about 18 to 25 degrees, and the heights of the first circulation block 40 and the second circulation block 50 are limited. HC1 of the first circulation block 40 is smaller than HC2 of the second circulation block 50. As a result, the present invention can be applied to the nut 30 having a smaller outer diameter, and can be adapted to the old and new specification nut 30, and in particular, can be adapted to the outer diameter of the nut 30 stipulated in the European Industrial Standard (DIN). it can.

The present invention can be applied to a ball screw.

11: Rotator 12: Nut 13: Screw shaft 14: Ball 16: Inner circulatory block 17: Outer circulatory block 18: Screw shaft 19: Nut 20: Screw shaft 21: Axis 22: Outer spiral groove 30: Nut 31: Inner spiral Groove 32: Circulating hole 33: Housing space 40: First circulating block 41: Upper surface 42: First divided surface 43: First receiving surface 44: First end surface 45: Localization portion 46: First circulating passage 47: Claw 50 : Second circulation block 51: second dividing surface 52: bottom surface 53: second receiving surface 54: second end surface 55: stereotactic recess 56: second circulation passage 58: lug 59: screw 91: ball 92: circulation passage 111: Claw 131: Outer spiral groove 171: Upper surface 172: Bottom surface 331: Groove bottom surface 332: Groove wall surface 581: Lock hole A: Angle

Claims (5)

A screw shaft having an axis and an outer spiral groove provided in a spiral shape around the axis;
A load path that is fitted to the screw shaft along the axis, includes an inner spiral groove that is spirally provided around the axis, and accommodates a plurality of balls by the outer spiral groove and the inner spiral groove; A circulation hole communicating with the inner spiral groove and a housing space provided along the axis from the end surface of the nut are formed, and the housing space includes a groove bottom surface corresponding to the outer spiral groove, and the circulation hole. A nut including a groove wall surface penetrated by,
The first circulation block is provided in the accommodating space along the axis and divided into a first circulation block and a second circulation block along the axis, and the first circulation block is located on the upper surface and in a direction opposite to the upper surface. The second circulation block includes a second divided surface that is flat and close to the first divided surface; and a bottom surface that is flat and leans to the groove bottom surface, A bottom surface and the second divided surface form an opening angle, a maximum distance between the first divided surface and the top surface is HC1, and a maximum distance between the second divided surface and the bottom surface is HC2. A circulator in which HC2 is larger than HC1,
A ball screw with a rotator characterized by comprising: The ball screw with a rotator according to claim 1, wherein the opening angle is about 18 to 25 degrees. A localization portion is provided on the first dividing surface of the first circulation block, a localization recess facing the bottom surface is provided on the second division surface of the second circulation block, and the localization portion is provided with the localization portion. The ball screw with a rotator according to claim 1, wherein the ball screw is fixed by being fitted with a recess. The first circulation block further includes a first circulation passage provided on the first dividing surface and facing the upper surface, and a claw provided on the outer spiral groove, and the second circulation block includes: Furthermore, it includes a second circulation passage provided on the second dividing surface and facing the bottom surface, and communicates with the circulation hole and the load passage through the second circulation passage and the first circulation passage. The ball screw with a rotator according to claim 1, wherein a circulatory passage is formed. The ball screw with a rotator according to claim 1, wherein both ends of the outer spiral groove of the screw shaft are closed.