JP2006144873A - Linear motion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion device capable of preventing an impact area to be damaged at low cost by increasing the strength of the impact area in the direction converting route of a circulation member by a simple treatment without increasing an increase in the size of the circulation member. <P>SOLUTION: The surface temperature of the impact area S1 is raised to an A3 transformation point or higher for ferrous metals and recrystallizing temperature or higher for non-ferrous metals by jetting roughly spherical polishing materials with a hardness equal to or higher than that of the inner diameter surface of the direction converting route 6 against the area S1 on which at least rolling elements B in the direction converting route 6 in the end cap 5 of a linear guide is collided. Also, WPC treatment is applied to the surface of the impact area S1 to form an oil sump formed of innumerable minute recessed parts formed in circular arc shape in cross section. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear motion device such as a linear guide, a ball spline, a linear ball bearing, or a ball screw that is used at a high speed.

  As a conventional linear guide, for example, the one shown in FIG. 12 is known. The linear guide includes a guide rail (guide shaft) 1 extending in the axial direction and a slider (movable body) 2 straddled on the guide rail 1 so as to be relatively movable in the axial direction.

  Rolling body rolling grooves (rolling body raceway surfaces) 3 extending in the axial direction are formed on both side surfaces of the guide rail 1. The slider body (movable body body) 2 A of the slider 2 has both sleeve portions 4. A rolling element rolling groove (rolling element raceway surface) 7 that faces the rolling element rolling groove 3 is formed on the inner side surface of the rolling element. A large number of balls B as an example of a rolling element are slidably loaded on the load trajectory between the two rolling elements rolling grooves 3 and 7 that face each other. The slider 2 can move relative to the guide rail 1 along the axial direction.

  Along with this movement, the ball B interposed between the guide rail 1 and the slider 2 rolls and moves to the end of the slider 2 in the axial direction, but the slider 2 continues to move in the axial direction. These balls B need to be circulated indefinitely.

  For this reason, the rolling element passage 8 penetrating in the axial direction is formed in the sleeve portion 4 of the slider body 2A, and substantially U-shaped end caps (circulation members) 5 are respectively attached to both ends of the slider body 2A. The direction change path 6 (refer to FIG. 13) curved in an arc shape that is fixed to the end cap 5 between the rolling element rolling grooves 3 and 7 and the rolling element passage 8. ) To form a rolling element infinite circulation trajectory. In FIG. 12, reference numeral 11 denotes a side seal fixed to the end surface of the slider body 2A together with the end cap 5 via a screw 12 or the like, 10 denotes an under seal attached to the lower surface of the slider body 2A, and 13 denotes a grease supply. It is a nipple.

  As a conventional ball screw, for example, the one shown in FIG. 14 is known. The ball screw includes a screw shaft (guide shaft) 21 extending in the axial direction and a nut (movable body) 22 screwed to the screw shaft 21 so as to be relatively movable in the axial direction.

  A spiral thread groove 23 (rolling member raceway surface) is formed on the outer peripheral surface of the screw shaft 21, and a spiral corresponding to the screw groove 23 is formed on the inner peripheral surface of the nut main body (movable body main body) 22 </ b> A of the nut 22. A shaped thread groove (rolling member raceway surface) 24 is formed.

  The screw groove 24 of the nut 22 and the screw groove 23 of the screw shaft 21 are opposed to each other to form a spiral load raceway between them, and a number of balls B as an example of rolling elements are formed on the load raceway. Is loaded so that it can roll. The nut 22 (or the screw shaft 21) is moved in the axial direction through the rolling of the ball B by the rotation of the screw shaft 21 (or the nut 22).

  Further, a part of the side surface in the circumferential direction of the nut 22 is a flat surface, and a pair of circulation holes 25 communicating between the screw grooves 23 and 24 are formed on the flat surface so as to straddle the screw shaft 21. Has been. Both ends of a substantially U-shaped circulation tube (circulation member) 27 having a direction change path 26 inside are fitted into the set of circulation holes 25, and revolves along a load region between both screw grooves 23 and 24. The ball B is scooped up from one end of the circulation tube 27 and guided to the outside of the nut 22 and returned to the load region from the other end to form a rolling element infinite circulation track.

  By the way, in a linear guide and a ball screw driven at high speed, the impact when the ball B collides with the direction change paths 6 and 26 of the end cap 5 and the circulation tube 27 and changes the direction of motion is large. The collision area of the ball B including the tongue portions 6a and 26a of 6, 26 (in the case of a linear guide, the tongue portion 6a of the end cap 5, the rolling element passage 8 of the slider body 2A, and the end cap 5 of the load track opening) Projection area S1 with respect to the direction change path 6 (see FIG. 13), in the case of a tube circulation type ball screw, the direction change of the tongue 26a of the circulation tube 27 and the end opening of the direction change path 26 of the circulation tube 27. Cracks are likely to occur in the projected area region S2 (see FIG. 3) for the path. For this reason, peeling starting from cracks is likely to occur on the inner diameter surfaces of the direction change paths 6 and 26, which may cause breakage or breakage.

Therefore, conventionally, for example, in the case of a tube circulation type ball screw, as shown in FIG. 15, a coating 28 made of a low friction material such as a fluororesin is applied to the inner diameter surface of the direction change path 26 of the circulation tube 27 and the ball B Proposals have been made to reduce the impact at the time of collision, and as shown in FIG. 16, the tongue 26a of the circulation tube 27 is made thick to improve impact resistance (for example, patents). Reference 1).
Japanese Patent Laid-Open No. 10-196654

  However, in the above-described linear motion device such as the linear guide and the ball screw, the end cap 5 and the circulation tube 27 are increased in size, and the modification is made to increase the strength by increasing the thickness of the tongue portions 6a and 26a. Further, there is a problem that the design change and the manufacturing process change are not limited to only the end cap 5 and the circulation tube 27 but extend to the entire slider 2 and the nut 22, leading to an increase in cost.

  The present invention has been made to eliminate such inconveniences, and the object thereof is to increase the strength of the collision region of the rolling elements in the direction change path of the circulating member without causing an increase in size of the circulating member. An object of the present invention is to provide a linear motion device that can be improved and can prevent damage to the collision area at a low cost.

The above object of the present invention is achieved by the following configurations.
(1) A guide shaft having a rolling element raceway surface, and a rolling element raceway surface facing the rolling element raceway surface of the guide shaft, and rolling of a large number of rolling elements inserted between these rolling element raceway surfaces. A movable body that moves relative to the guide shaft through movement, the movable body being attached to the movable body main body provided with the rolling body raceway surface, and In order to form a rolling element infinite circulation track for circulating the rolling element infinitely, a linear motion device comprising a circulation member having a direction change path communicating with the rolling element raceway surface,
A substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path is injected into at least the area of the direction change path of the circulation member where the rolling elements collide. The surface temperature is raised above the A3 transformation point in the case of ferrous metals, and higher than the recrystallization temperature in the case of non-ferrous metals, and an oil sump consisting of innumerable concave portions having a minute cross-sectional arc shape on the surface of the collision region. A linear motion device characterized in that it has been subjected to a process of forming
(2) The collision area is a projected area area of the opening of the rolling element endless circulation track of the movable body main body with respect to the direction change path or the direction change path of the opening of the direction change path of the circulation member. The linear motion device according to (1), which is a projected area region.
(3) The linear motion device according to (1) or (2), wherein a particle diameter of the abrasive is 20 to 200 μm, and an injection speed of the abrasive is 50 m / sec or more.

  According to the present invention, a substantially spherical abrasive having a hardness equal to or greater than the inner diameter surface of the direction change path is injected into at least the region of the direction change path of the circulation member that collides with the rolling element. In the case of a ferrous metal, the surface temperature of the region is increased to the A3 transformation point or higher, and in the case of a non-ferrous metal, the surface temperature is increased to a recrystallization temperature or higher, and the surface of the collision region includes innumerable concave portions having a small cross-sectional arc shape. Since the process for forming the oil sump is performed, the impact area in the direction change path of the circulation member can be improved by a simple process without increasing the size of the circulation member, and the damage of the collision area can be reduced. It can be prevented at a cost.

  Hereinafter, each embodiment of the linear motion device according to the present invention will be described with reference to the drawings. In the first and second embodiments of the present invention, a linear guide is taken as an example of the linear motion device, and in the third to eighth embodiments, a ball screw is taken as an example of the linear motion device. In the first and second embodiments of the present invention, only differences from the linear guide already described in FIGS. 12 and 13 will be described, and in the third and fourth embodiments, already described in FIG. Only differences from the tube circulation ball screw will be described.

(First embodiment)
First, as shown in FIG. 1, the linear guide according to the first embodiment of the present invention is a region S <b> 1 where the ball B of the direction change path 6 of the end cap 5 collides, that is, the direction change path 6 of the end cap 5. The projected surface area of the rolling element passage 8 of the slider body 2A and the opening of the load track (the opening of the rolling element infinite circulation track) and the inner diameter surface of the direction change path 6 with respect to the tongue 6a of the end cap 5 A substantially spherical abrasive having a hardness equal to or higher than that is injected to raise the surface temperature of the collision region to the A3 transformation point or more in the case of ferrous metals, and to the recrystallization temperature or more in the case of non-ferrous metals. WPC processing is performed.

By this WPC process, the following changes (i) to (iii) in the structure and shape occur in the region where the ball B of the direction change path 6 of the end cap 5 collides.
(I) The amount of retained austenite is reduced, and a martensite structure remarkably finer than that of a normal heat treatment is generated. Further, since it is heated to the γ-forming temperature in a short time simultaneously with precipitation hardening and cooled in a short time, the surface hardness is increased, the toughness is increased, and the internal residual compressive stress on the surface is increased.
(Ii) Also, since work hardening by injection of abrasives, especially plastic processing is performed with the generation of heat, ausforming is performed, and the surface hardness increases by promoting the formation of the martensite structure described above. .
(Iii) Furthermore, innumerable dimples having a minute circular arc shape are formed on the surface.
With these (i) to (iii), in the region S1 where the ball B of the direction change path 6 of the end cap 5 collides, the fatigue strength can be improved by the refinement of the structure and the toughness, and the refinement of the structure. The impact resistance can be improved. Further, the wear resistance can be improved by making the structure finer and the surface hardness can be increased, and the innumerable dimples can become oil reservoirs to improve the lubricity.

  Here, the surface temperature of the collision region in the case of a ferrous metal is higher than the A3 transformation point, and in the case of a non-ferrous metal, the collision energy of the abrasive that is reliably raised to the recrystallization temperature is generated, and In order for the generated dimples to have a minute size that functions as an oil reservoir, it is preferable that the particle size of the abrasive is 20 to 200 μm and the spraying speed of the abrasive is 50 m / sec or more.

  Thus, in the present embodiment, a substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path 6 with respect to the region S1 where the ball B of the direction change path 6 of the end cap 5 collides. The surface temperature of the collision area is increased to the A3 transformation point or more in the case of a ferrous metal, and to the recrystallization temperature or more in the case of a non-ferrous metal, and the surface of the collision area is formed into a minute cross-section arc shape. Since the WPC process for forming an oil sump consisting of innumerable dimples is performed, the strength of the collision area S1 in the direction change path 6 of the end cap 5 can be improved with a simple process without causing an increase in the size of the end cap 5. Thus, the tongue of the end cap 5, breakage, breakage, etc. of the inner diameter surface can be prevented at a low cost.

(Second Embodiment)
The linear guide according to the second embodiment of the present invention shown in FIG. 2 faces the slider body 2A side of the end cap 5 including the region S1 where the ball B of the direction change path 6 of the end cap 5 of FIG. In this example, the entire surface including the direction change path 6 is subjected to the WPC process described above, and in this way, the partial masking step required in the first embodiment can be omitted. Other configurations and operational effects are the same as those of the first embodiment.
When the end cap 5 is an integral part of the members constituting the rolling element passage 8, the direction changing path 6 of the end cap 5 is looked into only from the opening of the rolling element passage 8 on the side away from the end cap 5. Therefore, it is sufficient that the WPC process is partially performed as in the first embodiment.

(Third embodiment)
Next, as shown in FIG. 3, the tube circulation type ball screw according to the third embodiment of the present invention is a region S <b> 2 where the ball B of the direction change path 26 of the bifurcated circulation tube (circulation member) 27 collides. That is, the projected area of the end opening portion of the direction change path 26 of the circulation tube 27 with respect to the direction change path 26 and the tongue portion 26a of the circulation tube 27 are equal to or equal to the inner diameter surface of the direction change path 26. A substantially spherical abrasive having the above hardness is sprayed, and a WPC treatment is performed to raise the surface temperature of the collision region to the A3 transformation point or more in the case of ferrous metals and to the recrystallization temperature or more in the case of non-ferrous metals. ing.

  In the region S2 where the ball B of the direction change path 26 of the circulation tube 27 collides by this WPC process, the structure change and shape change of (i) to (iii) occur as in the first embodiment. In the region S2 where the ball B of the direction change path 26 of the tube 27 collides, the fatigue strength can be improved by refining the structure and improving the toughness, and the impact resistance can be improved by refining the structure. Further, the wear resistance can be improved by making the structure finer and the surface hardness can be increased, and the innumerable dimples can become oil reservoirs to improve the lubricity.

  Here, the surface temperature of the collision region in the case of a ferrous metal is higher than the A3 transformation point, and in the case of a non-ferrous metal, the collision energy of the abrasive that is reliably raised to the recrystallization temperature is generated, and In order for the generated dimples to have a minute size that functions as an oil reservoir, it is preferable that the particle size of the abrasive is 20 to 200 μm and the spraying speed of the abrasive is 50 m / sec or more.

  Thus, in this embodiment, a substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path 26 is applied to the region S2 where the ball B of the direction change path 26 of the circulation tube 27 collides. The surface temperature of the collision area is increased to the A3 transformation point or more in the case of a ferrous metal, and to the recrystallization temperature or more in the case of a non-ferrous metal, and the surface of the collision area is formed into a minute cross-section arc shape. Since the WPC process for forming an oil sump consisting of an infinite number of dimples is performed, the strength of the collision region S2 in the direction change path 26 of the circulation tube 27 can be improved by a simple process without causing an increase in the size of the circulation tube 27. Thus, breakage, breakage and the like of the tongue portion and inner diameter surface of the circulation tube 27 can be prevented at low cost.

(Fourth embodiment)
The tube circulation type ball screw according to the fourth embodiment of the present invention shown in FIG. 4 includes a direction change path of the circulation tube 27 including a region S2 where the ball B of the direction change path 26 of the split circulation tube 27 collides. This is an example in which the above-described WPC process is performed on the entire inner diameter surface of No. 26, and in this way, the partial masking step required in the third embodiment can be omitted. Other configurations and operational effects are the same as those of the third embodiment.
In addition, when the circulation tube 27 is a tube-like integral product, the WPC process should just be performed partially like the said 3rd Embodiment.

(Fifth embodiment)
An end cap type ball screw according to a fifth embodiment of the present invention shown in FIG. 5 is screwed to a screw shaft (guide shaft) 31 extending in the axial direction so as to be relatively movable in the axial direction. And a nut (movable body) 32.

  A spiral thread groove 33 (rolling member raceway surface) is formed on the outer peripheral surface of the screw shaft 31, and a spiral corresponding to the screw groove 33 is formed on the inner peripheral surface of the nut main body (movable body main body) 32A of the nut 32. A thread groove (rolling member raceway surface) 34 is formed.

  The screw groove 34 of the nut 32 and the screw groove 33 of the screw shaft 31 are opposed to each other to form a spiral load track between them, and a large number of balls B as an example of a rolling element are formed on the load track. Is loaded so that it can roll. The nut 32 (or the screw shaft 31) is moved in the axial direction through the rolling of the ball B by the rotation of the screw shaft 31 (or the nut 32).

  Further, a rolling element passage 35 penetrating in the axial direction is formed in the peripheral wall portion of the nut main body 32A, and between the rolling element passage 35 and the screw grooves 33, 34 on the end face in the axial direction of the nut main body 32A. An end cap (circulation member) 38 communicating with the load track is fixed through fixing means such as a screw 37.

  Referring to FIG. 6, end cap 38 is provided at direction change path 36 that communicates between rolling element passage 35 and the load track between both screw grooves 33, 34, and at the tip of direction change path 36. And a tongue portion 36a that scoops up the ball B rolling on the load track between the screw grooves 33 and 34.

  The direction change path 36 including the tongue 36a, the load trajectory between the screw grooves 33 and 34, and the rolling element passage 35 form a row of rolling element infinite circulation trajectories.

  Here, in this embodiment, as shown in FIG. 6, the region S3 where the ball B of the direction change path 36 of the end cap 38 collides, that is, the opening of the rolling element passage 35 of the nut body 32A (the rolling element infinite circulation). The collision area is formed by injecting a substantially spherical abrasive having a hardness equal to or greater than the inner diameter surface of the direction change path 36 to the projected area area of the end cap 38 on the direction change path 36 of the opening of the track). In the case of ferrous metals, the WPC treatment is applied to raise the surface temperature to the A3 transformation point or higher, and in the case of non-ferrous metals, the WPC treatment is raised to the recrystallization temperature or higher.

  As a result of the WPC process, the structure change and shape change (i) to (iii) above occur in the region where the ball B of the direction change path 36 of the end cap 38 collides as in the first embodiment. In the region S3 where the ball B of the direction change path 36 collides, the fatigue strength can be improved by refining the structure and improving the toughness, and the impact resistance can be improved by refining the structure. Further, the wear resistance can be improved by making the structure finer and the surface hardness can be increased, and the innumerable dimples can become oil reservoirs to improve the lubricity.

  Here, the surface temperature of the collision region in the case of a ferrous metal is higher than the A3 transformation point, and in the case of a non-ferrous metal, the collision energy of the abrasive that is reliably raised to the recrystallization temperature is generated, and In order for the generated dimples to have a minute size that functions as an oil reservoir, it is preferable that the particle size of the abrasive is 20 to 200 μm and the spraying speed of the abrasive is 50 m / sec or more.

  Thus, in this embodiment, a substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path 36 is applied to the region S3 where the ball B of the direction change path 36 of the end cap 38 collides. The surface temperature of the collision area is increased to the A3 transformation point or more in the case of a ferrous metal, and to the recrystallization temperature or more in the case of a non-ferrous metal, and the surface of the collision area is formed into a minute cross-section arc shape. Since the WPC process for forming an oil sump consisting of innumerable dimples is applied, the strength of the collision area S3 in the direction change path 36 of the end cap 38 can be improved with a simple process without causing an increase in the size of the end cap 38. Thus, breakage, breakage, etc. of the inner diameter surface of the end cap 38 can be prevented at a low cost.

(Sixth embodiment)
The end cap type ball screw according to the sixth embodiment of the present invention shown in FIG. 7 includes a nut body 32A of the end cap 38 including a region S3 where the ball B of the direction change path 36 of the end cap 38 of FIG. This is an example in which the above-described WPC process is performed on the entire surface including the direction changing path 36 facing to the side, and in this way, the partial masking step required in the fifth embodiment can be omitted. Other configurations and operational effects are the same as those of the fifth embodiment.

(Seventh embodiment)
A circulating top ball screw according to a seventh embodiment of the present invention shown in FIG. 8 is screwed to a screw shaft (guide shaft) 41 extending in the axial direction so as to be relatively movable in the axial direction. A nut (movable body) 42.

  A spiral thread groove 43 (rolling member raceway surface) is formed on the outer peripheral surface of the screw shaft 41, and a spiral corresponding to the screw groove 43 is formed on the inner peripheral surface of the nut main body (movable body main body) 42A of the nut 42. A threaded groove (rolling member raceway surface) 44 is formed.

  The screw groove 44 of the nut 42 and the screw groove 43 of the screw shaft 41 are opposed to each other to form a spiral load track between them, and a large number of balls B as an example of a rolling element are formed on the load track. Is loaded so that it can roll. The nut 42 (or the screw shaft 41) is moved in the axial direction through the rolling of the ball B by the rotation of the screw shaft 41 (or the nut 42).

  As shown in FIGS. 8 and 9, a circulating top fitting hole 45 is provided on the outer peripheral surface of the nut main body 42 </ b> A, and the fitting hole 45 has a substantially S-shaped direction changing path 46. A circulation top (circulation member) 47 is fitted.

  Thereby, the ball B rolling on the load track between the screw grooves 43 and 44 is guided by the scooping portion of the circulation top 47 over the land portion of the screw shaft 41 to the direction change path 46 inside the circulation top 47, A rolling element infinite circulation track in which the ball B circulates infinitely is returned to the load track between the adjacent screw grooves 43 and 44 via the direction change path 46.

  Here, in the present embodiment, as shown in FIG. 10, the direction change path with respect to the region S <b> 4 where the ball B of the direction change path 46 of the circulation top 47 collides, that is, the entire inner diameter surface of the direction change path 46. A substantially spherical abrasive having a hardness equal to or higher than that of the inner diameter surface of 46 is injected, and the surface temperature of the collision region is higher than the A3 transformation point in the case of ferrous metals, and the recrystallization temperature in the case of non-ferrous metals. The WPC process for raising the above is performed.

  Due to this WPC process, also in the region S4 where the ball B of the direction change path 46 of the circulation top 47 collides, the above-mentioned (i) to (iii) structural change and shape change occur, and therefore the direction change path 46 of the circulation top 47. In the region S4 where the ball B collides, fatigue strength can be improved by refining the structure and improving toughness, and impact resistance can be improved by refining the structure. Further, the wear resistance can be improved by making the structure finer and the surface hardness can be increased, and the innumerable dimples can become oil reservoirs to improve the lubricity.

  Here, the surface temperature of the collision region in the case of a ferrous metal is higher than the A3 transformation point, and in the case of a non-ferrous metal, the collision energy of the abrasive that is reliably raised to the recrystallization temperature is generated, and In order for the generated dimples to have a minute size that functions as an oil reservoir, it is preferable that the particle size of the abrasive is 20 to 200 μm and the spraying speed of the abrasive is 50 m / sec or more.

  Thus, in the present embodiment, a substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path 46 with respect to the region S4 where the ball B of the direction change path 46 of the circulation top 47 collides. The surface temperature of the collision area is increased to the A3 transformation point or more in the case of a ferrous metal, and to the recrystallization temperature or more in the case of a non-ferrous metal, and the surface of the collision area is formed into a minute cross-section arc shape. Since the WPC process for forming an oil sump consisting of innumerable dimples is performed, the strength of the collision area S4 in the direction change path 46 of the circulation top 47 can be improved with a simple process without causing an increase in the size of the circulation top 47. Thus, breakage, breakage, etc. of the inner diameter surface of the circulating top 47 can be prevented at low cost.

(Eighth embodiment)
The circulating top type ball screw according to the eighth embodiment of the present invention shown in FIG. 13 faces the nut main body 42A side of the circulating top 47 including the region S4 where the ball B of the direction change path 46 of the circulating top 47 collides. This is an example in which the above-described WPC process is performed on the entire surface including the direction change path 46, and in this way, the partial masking step required in the seventh embodiment can be omitted. Other configurations and operational effects are the same as those of the seventh embodiment.

In addition, this invention is not limited to said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in each of the above embodiments, a linear motion device such as a ball screw or a linear guide using a ball as a rolling element is taken as an example. The present invention may be applied to a linear motion device such as a roller screw device using a roller as a rolling element or a linear guide.

(A) is a perspective view for demonstrating the end cap of the linear guide which is the 1st Embodiment of this invention, (b) saw the end cap of (a) from the end surface side of the slider main body. FIG. It is a perspective view for demonstrating the end cap of the linear guide which is the 2nd Embodiment of this invention. It is a figure for demonstrating the circulation tube of the tube circulation type ball screw which is the 3rd Embodiment of this invention. It is a figure for demonstrating the circulation tube of the tube circulation type ball screw which is the 4th Embodiment of this invention. It is principal part sectional drawing for demonstrating the end cap type ball screw which is the 5th Embodiment of this invention. (A) is the perspective view which shows the end cap of the ball screw of FIG. 5, (b) is the figure which looked at the end cap of (a) from the end surface side of the nut main body. It is a figure for demonstrating the end cap of the ball screw which is the 6th Embodiment of this invention. It is principal part sectional drawing for demonstrating the circulating top type ball screw which is the 7th Embodiment of this invention. It is the perspective view which notched some nuts of FIG. It is a perspective view of a circulation top. It is a perspective view for demonstrating the circulation top of the circulation top type ball screw which is the 8th Embodiment of this invention. It is the perspective view which notched a part which shows an example of the conventional linear guide. It is the figure which looked at the end cap of the linear guide of FIG. 12 from the end surface side of the slider main body. It is principal part sectional drawing which shows an example of the conventional tube circulation type ball screw. (A) is a figure which shows the conventional circulation tube, (b) is sectional drawing along the XV-XV line | wire of (a). It is a figure which shows the conventional circulation tube.

Explanation of symbols

1 Guide rail (guide shaft)
2 Slider (movable body)
2A Slider body (movable body)
3 Rolling element rolling groove (Rolling body raceway surface: Guide rail side)
5,38 End cap (circulation member)
6, 26, 36, 46 Direction change path 7 Rolling body rolling groove (Rolling body raceway surface: slider body side)
B ball (rolling element)
S1, S2, S3, S4 Collision area 27 Circulation tube (circulation member)
21, 31, 41 Screw shaft (guide shaft)
22, 32, 42 Nut (working body)
22A, 32A, 42A Nut body (movable body)
47 Circulation top (circulation member)

Claims (3)

A guide shaft having a rolling element raceway surface, and a rolling element raceway surface opposite to the rolling element raceway surface of the guide shaft, and through the rolling of a large number of rolling elements inserted between the rolling element raceway surfaces. A movable body relatively moving along the guide shaft, and the movable body is attached to the movable body main body provided with the rolling body raceway surface, and the rolling body is mounted on the movable body main body. In order to form a rolling element endless circulation track that circulates indefinitely, a linear motion device comprising a circulation member having a direction change path communicating with the rolling element raceway surface,
A substantially spherical abrasive having a hardness equal to or higher than the inner diameter surface of the direction change path is injected into at least the area of the direction change path of the circulation member where the rolling elements collide. The surface temperature is raised above the A3 transformation point in the case of ferrous metals, and higher than the recrystallization temperature in the case of non-ferrous metals, and an oil sump consisting of innumerable concave portions having a minute cross-sectional arc shape on the surface of the collision region. A linear motion device characterized in that it has been subjected to a process of forming   The collision area is a projected area area of the opening of the rolling element infinite circulation track of the movable body main body with respect to the direction change path, or a projected area area of the opening of the direction change path of the circulation member with respect to the direction change path. The linear motion device according to claim 1, wherein:   The linear motion device according to claim 1, wherein the abrasive has a particle size of 20 to 200 μm and an injection speed of the abrasive is 50 m / sec or more.

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