JP2001082469A - Linear motion rolling guide unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply lubricating oil to a rolling element for a long period to improve durability forming a return passage hole formed on a slider with sintered resin member consisting of porous structure. SOLUTION: In this linear motion rolling guide unit, a ball 20 is circulated infinitely in a slider 2 possible to slide freely to a track rail 1 through plural rolling elements such as the ball 20 and the like. For that purpose, a sleeve type sintered resin member 30 with a porous structure is inserted in an insert hole 26 and a return passage hole 22 to pass the ball 20 is formed inside of the sintered resin member 30. Lubricating oil or grease is absorbed into the inside of the porous structure in the sintered resin member 30, and is applied continuously to the passing ball 20 for a long period. Therefore, the raceway track 21 is lubricated through the ball 20 to improve durability and to decrease the sliding resistance of the slider.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion rolling guide unit which guides a track rail and a slider relatively linearly and slidably through the rolling of a rolling element.

[0002]

2. Description of the Related Art Conventionally, a linear motion rolling guide unit is a unit in which a slider is slidable on a long track rail (or track shaft) via a plurality of rolling elements (balls or rollers). The rolling elements circulate infinitely between the raceway rail and the raceway groove (or raceway surface) of the slider. To prevent the metal contact between the raceway groove and the rolling element and achieve the rated durability life,
It is indispensable to supply the lubricant between the raceway groove and the rolling element without cutting, thereby ensuring the lubrication between the two. Lubrication between the raceway grooves and the rolling elements is normally ensured by periodic lubrication.

[0003] In recent years, maintenance-free is required for various types of machinery due to energy saving and cost reduction for maintenance of equipment, and the linear motion rolling guide unit incorporated in the machinery also requires maintenance for lubrication. There is a demand for free implementation. In addition, as for the linear motion rolling guide unit incorporated in a clean room specification device such as a semiconductor manufacturing device, one having a low dusting property is demanded, and in consideration of the fact that the lubricant becomes fine particles and generates dust, There is a need to minimize the use of lubricants.

Regarding lubrication of linear motion bearings with rails,
A self-lubricating member forms a circulation hole formed in the slide body and through which the ball passes for infinite circulation, thereby lubricating the ball circulating in the circulation hole and eliminating the need to apply a lubricant to the slide body and the rail. One has been proposed (Japanese Utility Model Application Laid-Open No. 64-41724). The circulation hole is
For example, it is formed by fitting a self-lubricating member formed into a pipe shape such as an oilless metal into a hole formed in the slider body.

A lubricating linear guide device in which a lubricant-containing polymer member which comes into contact with a rolling element is disposed inside a slider of the linear guide apparatus, and which automatically supplies a stable and stable lubricant to the rolling element for a long period of time. (Japanese Patent Laid-Open No. 7-54444). The lubricant-containing polymer member is formed by mixing and heating and melting a polyolefin-based polymer and a poly-α-olefin oil, and then pouring the mixture into a predetermined mold and cooling and solidifying it under pressure. Further, it has been proposed to form a lubricant-containing polymer member by integrally molding a lubricant-containing polymer and a reinforcing material (Japanese Patent Application Laid-Open No. H10-78032).

The present applicant further provides a linear motion guide unit comprising a track rail having track grooves formed on both side surfaces in the longitudinal direction, and a slider relatively sliding on the track rail.
A lubricating plate made of a sintered resin member having a porous structure impregnated with lubricating oil is disposed on the end face of a slider, and lubrication of a raceway groove in which a rolling element circulates is proposed (Japanese Patent Laid-Open No. Hei 1 (1999)).
0-205534).

Each of the above proposals eliminates the need for applying a lubricant when used in a light room with a clean room specification. It is not satisfactory. The lubricant-containing polymer member must be molded by mixing a lubricating oil in molding, and must be reinforced with a reinforcing material in actual use, requiring a high level of technology. Further, when the lubricating plate is provided on the slider, the lubricating plate is in sliding contact with the raceway groove, so that when used in an apparatus with a high speed and a high cycle, the sliding resistance increases.

[0008]

Therefore, a linear motion rolling guide which guides the track rail and the slider relatively linearly slidably through the rolling of a rolling element which circulates infinitely through a return passage hole formed in the slider. In the guidance unit,
The lubricating oil supply member, which is installed in the return passage hole and supplies lubricating oil to the rolling elements, has a structure that has sufficient strength by itself without reinforcing with a reinforcing material, so that the rolling elements can run smoothly for a long time There is a problem to be solved in that it is possible to keep supplying the lubricating oil to the rolling elements while making it possible.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide an infinite circulation including an orbital path and an orbital path even when used in a severe environment under an atmosphere or a supporting load. This eliminates the need for periodic lubricant application and lubricating oil supply maintenance that should be applied to rolling elements that pass along the road, and can be applied to high-speed, high-cycle devices with reduced sliding resistance in the raceway. It is an object of the present invention to provide a linear motion rolling guide unit capable of performing lubrication at low cost.

According to the present invention, a long track member, a slider relatively movable in a longitudinal direction of the track member, and a track path formed between the track member and the slider are rolled to form the slider. The present invention relates to a linear motion rolling guide unit comprising a rolling element that circulates infinitely through a return passage hole formed, wherein the return passage hole is formed of a sintered resin member having a porous structure.

According to this linear motion rolling guide unit, since the sintered resin member has a porous structure, it functions as an absorber, and lubricating oil or grease is supplied to the sintered resin member at the beginning of assembly. For example, the sintered resin member absorbs and retains the oil content of the lubricant in the porous structure of the porous structure, and the retained lubricant is always supplied to the rolling elements passing through the return passage holes. The rolling element with the lubricant adheres to the raceway formed between the raceway member and the slider and rolls, thereby also lubricating (oiling) the raceway groove and the raceway surface. The porous structure of the sintered resin member can absorb not only oil but also special components (solid lubricating fine particles, film forming fine particles, and other additives).

Since the sintered resin member itself has sufficient strength, it does not need to be reinforced, and since the generation of wear powder is small, the porous structure is not clogged with the wear powder, and is formed. The lubricant retained by lubricating the porous structure is supplied to the rolling elements for a long time. Therefore, even under the use of a special environment such as a high temperature or the use of a small amount of lubricant, metal contact between the rolling elements and the raceway grooves or raceway surfaces constituting the raceway is prevented, and the lubricity is further improved. Of course, the porous structure of the sintered resin member may be formed with the lubricating oil impregnated in advance.

[0013] The sintered resin member having the porous structure is formed of a polymer sintered porous body. The polymer sintered porous body is formed by filling ultra-high molecular weight synthetic resin fine particles into a predetermined mold and performing heat molding. The ultra-high molecular weight synthetic resin fine particles are heat-formed in a compacted state to form a porous structure. Heat molding using a mold makes it possible to produce a large amount of sintered resin members at low cost.

As the synthetic resin fine particles, polyethylene,
Examples thereof include polypropylene and ethylene tetrafluoride polymer. In particular, ultrahigh molecular weight polyethylene fine particles are a material from which a molded product can be manufactured with high precision, and the molded sintered resin member has excellent wear resistance.

The sintered resin member is formed in a sleeve shape, and the return passage hole is formed inside a sleeve of the sintered resin member inserted into an insertion hole formed in the slider. The sintered resin member is formed in a sleeve shape, and is fitted into a fitting hole formed in the slider so that the inside of the sleeve is formed in a return passage hole through which a rolling element passes. Therefore, the diameter of the return passage hole is large enough to allow the rolling elements to pass through, and the fitting hole formed in the slider is formed to have a hole diameter in consideration of the sleeve thickness of the sintered resin member in the hole diameter of the return passage hole. You. The sintered resin member is formed into a sleeve shape by rolling a sheet formed into a porous structure and by aligning a symmetrical half sleeve formed into a porous structure. By rounding the sheet-shaped sintered resin member or aligning the half-sleeved sleeve, the molding and processing of the sintered resin member is easy without the need for a core, and the production of the return passage hole is also easy. .
The sintered resin member is formed as a part of the slider in the porous structure and is formed in a block shape in which the return passage hole is formed.

The sintered resin member has a lubricant reservoir such as a concave portion or a slit. By providing the lubricant pool portion in the sintered resin member, excess lubricant is easily absorbed, and the lubricant absorbed in the lubricant pool portion is supplied to the rolling elements for a long time in small amounts.

In this linear motion rolling guide unit, the rolling elements are formed on the slider in opposition to the first raceway grooves formed on both longitudinal side surfaces of the raceway rail as the raceway member and the first raceway grooves. A ball that rolls on the orbital path consisting of a second orbital groove formed by the slider and the slider,
A casing in which the second raceway groove and the return passage hole are formed, and a direction changing path for attaching the ball to both end surfaces of the casing and changing the direction of the ball from the raceway path to the return passage hole. It has an end cap formed. As the track member and the slider, a type including a track rail and a slider that straddles the track rail, or a type including a track axis and a cylindrical slider that surrounds the track axis may be used.

In this linear motion rolling guide unit, the rolling elements are formed on the slider in opposition to the first raceway surfaces formed on both longitudinal side surfaces of the raceway rail as the raceway member and the first raceway surface. A cylindrical roller that rolls on the orbital path formed by the second track surface, wherein the slider is provided on a casing in which the second track surface and the return passage hole are formed, and on both end surfaces of the casing. Each end cap has an end cap formed therein and formed with a turning path for turning the cylindrical roller from the track path to the return passage hole.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a linear motion rolling guide unit according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view showing an embodiment of a linear motion rolling guide unit according to the present invention, FIG. 2 is a side view showing a partly broken down linear motion rolling guide unit shown in FIG.
FIG. 3 is a view of the linear motion rolling guide unit shown in FIG.
FIG. 4 is a perspective view showing a plurality of examples of the sintered resin member used when the rolling element is a ball.

In the embodiment shown in FIGS. 1 to 4, the linear motion rolling guide unit is generally a unit applied between members to be relatively moved such as a bed and a table, and includes a track rail 1; A slider 2 slidable on the track rail 1. First track grooves 4, 4 are respectively formed on a pair of longitudinal side surfaces 3, 3 facing the outside of the track rail 1.
Are formed. A mounting hole 6 for mounting the track rail 1 to the bed 8 is opened in the upper surface 5 of the track rail 1.

The slider 2 includes a casing 10 that straddles the upper surface 5 of the track rail 1, an end cap 11 that is mounted in contact with both longitudinal end faces of the casing 10, and a gap between the track rail 1 and the end cap 11. An end seal 12 is provided on the end face of the end cap 11 for sealing. The end cap 11 and the end seal 12 are mounted on the casing 10 by mounting screws 13. The casing 10 has a second track groove 14 at a position facing the first track groove 4 of the track rail 1, and a top surface 1 for attaching the slider 2 to the table.
5, a screw hole 16 is formed. In order to seal a gap between the casing 10 and the end cap 11 and both longitudinal side surfaces 3 of the track rail 1, a lower surface seal 17 is provided on the lower surface of the end cap 11 and the casing 10.
(FIG. 3) is attached.

In order to make the slider 2 slidable with respect to the track rail 1, a first track groove 4 formed in the track rail 1 and a second track groove 14 formed in the casing 10.
The ball 20 as a rolling element can roll on the load orbit path 21 formed between them. The ball 20 is the slider 2
Is held on the casing 10 by the holding band 24 so as not to be dissipated even when the member is separated from the track rail 1. The ball 20 rolls on the load raceway 21 and includes a return passage hole 22 formed in the casing 10 and a direction change passage formed on both end caps 11 and connected to the load raceway passage 21 and the return passage hole 22. Endless circulation is possible by moving along the no-load orbit. Ball 2
A grease nipple 25 for supplying grease to the end cap 11 is attached to the end cap 11 so as to protrude from the outer surface of the end seal 12. The above-described structure is a configuration that also includes a conventional linear motion rolling guide unit.

The linear motion rolling guide unit according to the present invention comprises:
It has a characteristic structure in the following points. That is, the return passage hole 22 is formed as a space inside the sleeve of the sintered resin member 30 by disposing the sleeve-shaped sintered resin member 30 in the casing 10. Therefore,
The casing 10 has a fitting hole 2 having a diameter obtained by adding the thickness of the sintered resin member 30 to the passage diameter through which the ball 20 can pass, that is, an inner diameter corresponding to the outer diameter of the sintered resin member 30.
6 are formed, and the sintered resin member 30 is inserted into the insertion hole 26. When the both ends of the sintered resin member 30 abut on the end cap 11, movement in the longitudinal direction along the fitting hole 26 is restricted.

FIG. 4A shows an example of forming a sleeve-shaped sintered resin member 30 in which a return passage hole 22 through which the ball 20 passes is formed. Sintered resin member 30
Has a straight sleeve shape in which no slits or the like are formed. FIG. 4B shows a sintered resin member 31 having another structure. Sintered resin member 31
Is formed by forming a slit 32 in the longitudinal direction of the sintered resin member 30 shown in FIG. The slit 32
It has a function as a lubricating oil reservoir, and although only one strip is shown in the figure, a plurality of strips may be formed at intervals in the circumferential direction. For example, at the beginning of the assembly, lubricating oil such as grease filled from the grease nipple 25 reaches the sintered resin member 30 and is retained in the slit 32, and the lubricating oil in the slit 32 is a porous structure of the sintered resin member 31. And is supplied to the ball 20 passing through the return passage hole 22 for a long time.

FIG. 4C shows a sintered resin member 33 having still another structure. The sintered resin member 33 is
Large diameter portions 34, 34 are formed at both ends, and both large diameter portions 34, 3
4, a small diameter portion 35 is formed. Small diameter part 35
Has a slit 36 formed along the longitudinal direction. Fitting insertion hole 26 of casing 10 (see FIGS. 1 to 3)
Since the large-diameter portion 34 is formed uniformly with the inner diameter in which the large-diameter portion 34 is just inserted, lubrication capable of holding grease is provided between the outer peripheral surface of the small-diameter portion 35 and the insertion hole 26. An annular recess 37 is formed as an oil reservoir. Recess 3
The lubricating oil such as grease can enter and exit from the slit 7 through the slit 36. The lubricating oil in the recess 37 is the sintered resin member 3
3 and is supplied to the ball 20 passing through the return passage hole 22 for a long time. Since the rigidity of the sintered resin member 33 is reduced at the small diameter portion 35 and is easily elastically deformed, the movement of the ball 20 is further smoothed.

FIG. 4D shows a sintered resin member 40 having still another structure. The sintered resin member 40 is
Large diameter portions 41 and 42 are formed at both ends, respectively, and rib portions 43 having the same diameter as the large diameter portions 41 and 42 are formed at the center. A small diameter portion 4 is provided between the large diameter portion 41 on one end side and the rib portion 43 and between the large diameter portion 42 and the rib portion 43 on the other end side.
4, 45 are formed. Slits 46 and 47 are formed in the small diameter portions 44 and 45 along the longitudinal direction, respectively. Similar to the sintered resin member 33 shown in FIG.
Annular concave portions 48 and 49 are formed between the outer peripheral surfaces of the small diameter portions 44 and 45 and the fitting holes 26 and function as lubricating oil reservoirs capable of holding grease. The rib portion 43 may be provided at a plurality of locations between the large-diameter portions 41 and 42, and the small-diameter portion 4
4, 45, it is possible to have reduced strength reinforcing action. The lubricating oil in the recesses 48 and 49 is absorbed by the sintered resin member 40 and supplied to the ball 20 passing through the return passage hole 22 for a long time.

FIG. 4E shows a sintered resin member 50 having still another structure. The sintered resin member 50 is
By forming a plurality of grooves in the longitudinal direction on the inner surface of the sleeve forming the return passage hole 22, the groove is formed on the uneven surface. The convex portion 51 of the concave-convex surface serves as a passage surface of the ball 20, and the groove-shaped concave portion 52 functions as a lubricating oil reservoir for holding grease. Since the contact area with the ball is reduced and lubricating oil can be sufficiently supplied, the sliding resistance of the slider 2 to the track rail 1 is expected to be reduced. The lubricating oil in the concave portion 50 is absorbed by the sintered resin member 50 and supplied to the ball 20 passing through the return passage hole 22 for a long time. The structure of the uneven surface is shown in FIGS.
The present invention is also applicable to the sintered resin members 30, 31, 33, and 40 shown in FIG. Also, as for the sintered resin members 31, 33, and 40 in which the slits 32, 36, 46, and 47 shown in FIGS. 4B to 4D are formed, the outer peripheral surface may be formed as an uneven surface. .

FIG. 5 shows a sintered resin member 60 when the rolling elements are rollers (cylindrical rollers). FIG. 5 (A)
FIG. 3 is a cross-sectional view of a sintered resin member when the rolling elements are rollers (cylindrical rollers), and FIG. 2B is a side view of the sintered resin member shown in FIG. The sintered resin member 60 shown in the figure is configured by uniting half sleeves 61 having the same shape, and a concave groove 63 is formed on the inner surface of each half sleeve 61. In a state in which the two half sleeves 61 are combined, the outer shape is the fitting hole 26 formed in the casing 10.
(See FIGS. 1 to 3).
3, 63 are aligned with each other to form a return passage hole 62 having a rectangular cross section through which the rollers as the rolling elements pass.

FIG. 6 shows still another example of the sintered resin member used for the linear motion rolling guide unit. FIG.
FIG. 6 is a cross-sectional view of a slider in which a sintered resin member as yet another example is incorporated. As shown in FIG. 6, the sintered resin member 70 having a porous structure is formed not in a sleeve shape but in a block shape having a return passage hole 72 formed therein. Block-shaped sintered resin member 7
Reference numeral 0 fits into a complementary groove 71 formed in the casing 10 and is fitted to a pair of legs 10b extending from the casing main body 10a of the slider 2 to be integrated with the casing 10. Although the sintered resin member formed in a sleeve shape becomes structurally thin, it can hold a sufficient amount of lubricating oil by being formed in a block shape. If the strength of the legs 10b and the like of the casing 10 is insufficient, the strength can be increased by applying a cover that covers the casing 10.

FIGS. 7 and 8 show another embodiment of the linear motion rolling guide unit according to the present invention. FIG. 7 is a perspective view showing an embodiment in which the linear motion rolling guide unit according to the present invention is applied to a ball spline, and FIG. 8 is a cross-sectional view of the linear motion rolling guide unit shown in FIG. 7 and 8
The linear motion rolling guide unit shown in FIG. 2 is different from the linear motion rolling guide unit shown in FIGS. 1 to 3 in that a track rail 1 having a square cross section and a slider 2 bridging the track rail 1 are replaced with a round shaft cross section. It differs in that it is applied to a ball spline using a raceway shaft 81 and a cylindrical slider 82 surrounding the raceway shaft 81, but otherwise differs functionally from the linear motion rolling guide unit shown in FIGS. Therefore, components having the same functions are denoted by the same reference numerals as those assigned to the linear motion rolling guide unit shown in FIGS. 1 to 3, and detailed description is omitted. The insertion hole 26 is formed in the cylindrical slider 82 so as to extend in the longitudinal direction, and the sleeve-shaped sintered resin member 30 is inserted into the insertion hole 26. A return passage hole 22 is formed inside. A key groove 83 for attachment is formed on the outer surface of the slider 82.

FIGS. 9 to 12 show still another embodiment of the linear motion rolling guide unit to which the present invention is applied. FIG. 9 is a perspective view, partially cut away, of a further embodiment of a linear motion rolling guide unit to which the present invention is applied.
0 is a cross-sectional view of the linear motion rolling guide unit shown in FIG. 9, FIG.
1 is a cross-sectional view showing a state in which a return passage hole is formed by aligning the two sintering resin members in the linear motion rolling guide unit shown in FIG. 9, and FIG. 12 is a part of the linear motion rolling guide unit shown in FIG. It is an exploded perspective view.

In the linear motion rolling guide unit shown in FIGS. 9 to 12, the track rail 91 and the slider 92 can be relatively slid relative to the linear motion rolling guide unit shown in FIGS. Therefore, a cylindrical roller 90 is used instead of the ball 20 as a rolling element that circulates infinitely, and there is no difference in the basic structure as a linear motion rolling guide unit except for the structure related thereto. Therefore, components having the same functions are denoted by the same reference numerals as those shown in FIGS. 1 to 3, and overlapping detailed description will be omitted.
Since the rolling element is the cylindrical roller 90, two pairs of first track surfaces 9 opened vertically are provided on both longitudinal side surfaces 3 of the track rail 91.
The slider 92 has two pairs of second track surfaces 95, 95 opposed to the first track surfaces 94, 94.
Are formed. Between the facing track surfaces 94 and 95,
Two pairs of load track paths 96 on which the cylindrical rollers 90 roll are formed.

Load track path 9 configured as a pair up and down
6 and 96, the cylindrical rollers 90 are movable with respect to the rail groove 97 of the track rail 91 through a slight gap.
Holding plate 98 for holding the casing 10 of the slider 92
It is attached to 0. In order to seal a gap between the casing 100 and the end cap 11 and both longitudinal side surfaces 3 of the track rail 91, the end cap 11 is used.
A lower surface seal 99 is attached to the lower surface of the casing 100. Further, the lip 93 of the end seal 12 seals between the upper surface 5 of the track rail 91 and the slider 92.

A return passage hole 101 is formed in the casing 100 of the slider 92 so as to extend in parallel with the second raceway surface 95, and the end cap 11 has a cylindrical roller 90.
A direction changing path for changing the direction from the track path 96 to the return passage hole 101 is formed. The cylindrical roller 90 is infinitely circulating through a no-load orbital path including a load orbital path 96, a direction change path formed in the end cap 11, and a return passage hole 101 formed in the casing 100. To achieve lubrication maintenance-free, cylindrical rollers 90
The return passage hole 101 through which is passed is formed inside a sintered resin member 102 having a porous structure capable of holding the lubricating oil inserted into the insertion hole 108 of the casing 100 over its entire length.

The sintered resin member 102 is constituted by half sleeves 104, 104 divided into two on a rolling surface (track surface) 103 on which the cylindrical roller 90 rolls along its longitudinal direction. Each half sleeve 104, 104
It is preferable that they are connected to each other by a concave-convex fitting (not shown), but in the connected state, they are aligned at the contact surfaces to form a return passage hole 101 inside, and the outer periphery is fitted into the fitting insertion hole 108. Surface 106. Since the half sleeves 104 are connected to each other, the return passage hole 101 can be elastically deformed when the alignment at the contact surfaces 105, 105 of the split surfaces comes into contact with or separate from each other. Further, at both ends of the half sleeves 104, 104, although not shown,
The cylindrical roller 90 is chamfered and smoothly formed on the wall of the passage so that the cylindrical roller 90 can smoothly roll and move to the turning path.

In order for the half sleeves 104, 104 to further facilitate elastic deformation, the half sleeves 104, 10
4 includes a cylindrical roller 90 that rolls in the return passage hole 101.
A slit 107 is formed on the rolling axis and extending in the longitudinal direction of the half sleeves 104, 104. By forming the slit 107, the lubricant can enter and exit the sintered resin member 102 through the slit 107. Therefore, the sintered resin member 102 and the casing 10
The lubricant (lubricating oil) in the slit 107 is
It is absorbed by the sintered resin member 102 and supplied to the cylindrical roller 90 passing through the return passage hole 101 for a long time.

The sintered resin member 3 having the above porous structure
Reference numerals 0, 31, 33, 40, 50, 60, and 102 (hereinafter, reference numerals are omitted for a sintered resin member to avoid complexity) are made of a polymer sintered porous body and have an ultra-high molecular weight. Is molded by filling a predetermined mold with the synthetic resin fine particles and heat molding. Examples of the synthetic resin fine particles include polyethylene, polypropylene, and tetrafluoroethylene polymer. Ultra-high molecular weight polyethylene microparticles are materials that can produce molded products with high precision.
The molded sintered resin member has excellent wear resistance. Therefore, the sintered resin member does not need to be reinforced by the reinforcing material, and further, does not wear and does not cause clogging of the porous structure due to abrasion powder. To the load track. As described above, the sintered resin member can be easily manufactured into a sleeve shape in which a return passage hole is formed by rolling a sheet-shaped member or aligning a pair of half sleeves.

The ultrahigh molecular weight polyethylene fine particles have, for example, a fine particle size of 30 μm and a coarse particle size of 250 to 300 μm.
When the porous structure is heated and molded and sintered, the porous structure becomes a structure composed of open pores having a porosity of, for example, 40 to 50%. The absorption of the lubricating oil into the porous structure is completed, for example, in a case where the lubricating oil is immersed in turbine oil and impregnated, in about 30 minutes with the lubricant content being 41%. In the case of grease, the oil component absorbs about 70% of the above 41% in two days.

[0039]

Since the present invention is configured as described above, it has the following effects. That is, in a linear motion rolling guide unit in which a rolling element rolls on a track path formed between the track member and the slider for relative movement, a return passage hole formed in the slider for infinite circulation of the rolling element. Is formed by fitting a sintered resin member having a sleeve-like porous structure into the fitting insertion hole of the casing, so that the sintered resin member serves as an absorber for absorbing lubricating oil and grease into the porous structure. The lubricating oil or grease is absorbed and held in the porous structure. The lubricating oil or grease absorbed and held in the porous structure is consumed by being slightly attached to the rolling element when the rolling element passing through the return passage hole comes into contact with the sintered resin member, and the lubricating oil attached to the rolling element is consumed. Oil or grease is supplied to the raceway as the rolling elements pass the raceway. Since the sintered resin member itself has sufficient strength, it does not require reinforcement, and since the generation of wear powder is small, the porous structure is not clogged with the wear powder, and is maintained in the porous structure. The lubricating oil or grease thus obtained can be supplied to the rolling elements for a long time. Therefore, even under the use of special environment such as high temperature or the use of a small amount of lubricant, metal contact between the rolling element and the raceway groove or raceway surface that constitutes the raceway is prevented, and the lubricity is further improved, The durability as a rolling guide unit can be increased. Further, maintenance such as periodic application of a lubricant and supply of a lubricating oil is not required, and the sliding resistance in an orbital path can be suppressed and applied to a high-speed and high-cycle apparatus.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of a linear motion rolling guide unit according to the present invention.

FIG. 2 is a side view showing a part of the linear motion rolling guide unit shown in FIG.

3 is a view of the linear motion rolling guide unit shown in FIG.
It is sectional drawing seen in A.

FIG. 4 is a perspective view showing an example of a sintered resin member when a rolling element is a ball in a linear motion rolling guide unit according to the present invention.

FIGS. 5A and 5B are a cross-sectional view of a sintered resin member when a rolling element is a roller in the linear motion rolling guide unit according to the present invention, and a side view of the sintered resin member, respectively.

FIG. 6 is a sectional view of a slider in which a sintered resin member as still another example is incorporated.

FIG. 7 is a perspective view showing an embodiment in which the linear motion rolling guide unit according to the present invention is applied to a ball spline.

FIG. 8 is a sectional view of the linear motion rolling guide unit shown in FIG. 7;

FIG. 9 is a perspective view, partially cut away, of another embodiment of the linear motion rolling guide unit to which the present invention is applied.

10 is a sectional view of the linear motion rolling guide unit shown in FIG.

11 is a cross-sectional view showing a state in which a return passage hole is formed by aligning two split resin members in the linear motion rolling guide unit shown in FIG. 9;

FIG. 12 is an exploded perspective view showing a part of the linear motion rolling guide unit shown in FIG. 9;

[Explanation of symbols]

1,91 Track rail (track member) 2,92 Slider 3 Longitudinal side face 4 First track groove 10,100 Casing 11 End cap 14 Second track groove 20 Ball (rolling element) 21,96 Track path 22,62,72 Return passage hole 25 Grease nipple 26, 108 Fitting insertion hole 30, 31, 33, 40, 50, 60, 70, 102
Sintered resin member 32, 36, 46, 47 Slit (lubricant pool) 37, 48, 49, 52 Concave (lubricant pool) 81 Orbital shaft (track member) 82 Slider 90 Cylindrical roller (rolling element) 94 1 track surface 95 second track surface 104 half sleeve

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shigemasa Itabashi 392 Tokiwa, Kamakura-shi, Kanagawa F-term in Thomson Japan (reference) 3J104 AA03 AA23 AA34 AA57 AA63 AA64 AA69 AA74 AA76 BA23 CA14 CA23 CA24 CA33 DA05

Claims (11)

[Claims] 1. A long track member, a slider relatively movable in a longitudinal direction of the track member, and a track formed between the track member and the slider by rolling on the slider. A linear motion rolling guide unit comprising: a rolling element that circulates infinitely through a return passage hole, wherein the return passage hole is formed of a sintered resin member having a porous structure. 2. The linear motion rolling guide unit according to claim 1, wherein the sintered resin member is formed of a sintered polymer porous body. 3. The direct-polymer sintered porous body according to claim 2, wherein said porous sintered polymer body is formed by filling ultra-high molecular weight synthetic resin fine particles into a predetermined mold and performing heat molding. Dynamic rolling guide unit. 4. The synthetic resin fine particles are polyethylene,
4. The linear motion rolling guide unit according to claim 3, comprising a polypropylene or a polytetrafluoroethylene polymer. 5. The sintered resin member is formed into a sleeve shape, and the return passage hole is formed inside a sleeve of the sintered resin member inserted into an insertion hole formed in the slider. The linear motion rolling guide unit according to any one of claims 1 to 4, comprising: 6. The linear motion rolling guide unit according to claim 5, wherein the sintered resin member is formed in a sleeve shape by rolling a sheet formed into the porous structure. 7. The sintered resin member is formed in a sleeve shape by aligning a half sleeve having a symmetrical structure formed into the porous structure.
The linear motion rolling guide unit according to 1. 8. The sintered resin member is formed as a part of the slider in the porous structure, and is formed in a block shape in which the return passage hole is formed. 5. The linear motion rolling guide unit according to any one of the above items 4. 9. The linear motion rolling guide unit according to claim 5, wherein a lubricant reservoir such as a concave portion or a slit is formed in the sintered resin member. 10. A rolling element comprising: a first raceway groove formed on both longitudinal side surfaces of a raceway rail as the raceway member; and a second raceway groove formed on the slider so as to face the first raceway groove. The slider is mounted on the casing in which the second raceway groove and the return passage hole are formed, and the slider is attached to both end faces of the casing, and the ball is mounted on the slider. The linear motion rolling guide unit according to any one of claims 1 to 9, further comprising an end cap having a direction change path for changing a direction from the track path to the return passage hole. 11. The rolling element includes a first raceway surface formed on both longitudinal sides of a raceway rail as the raceway member, and a second raceway surface formed on the slider facing the first raceway surface. The slider is a cylindrical roller that rolls on the track path, the slider being attached to both ends of the casing, the casing having the second track surface and the return passage hole, and the cylindrical roller being attached to both ends of the casing. The linear motion rolling guide according to any one of claims 1 to 9, wherein the roller has an end cap having a direction change path for changing the direction from the track path to the return passage hole. unit.