CN116438385A

CN116438385A - Linear guide

Info

Publication number: CN116438385A
Application number: CN202180076392.8A
Authority: CN
Inventors: 工藤铁也; 中川匠
Original assignee: NSK Ltd
Current assignee: NSK Ltd
Priority date: 2020-11-16
Filing date: 2021-10-27
Publication date: 2023-07-14
Also published as: WO2022102413A1; KR20230082040A; JP2022079259A

Abstract

The invention provides a linear guide whose lubrication unit can stably supply lubricant for a long time. The lubricant supplying member is formed in a substantially C-shape and includes a pair of sleeve portions formed at left and right side surfaces of the rail, and a connecting portion connecting the pair of sleeve portions, the pair of sleeve portions having protrusions capable of sliding contact with the rail-side raceway surface of the rail. The lubrication unit includes a pair of side pressing units attached to side walls of the housing, the side walls being provided on the outer sides of the pair of sleeve portions in the width direction of the slider, and pressing the pair of sleeve portions toward the inner sides of the slider in the width direction, respectively.

Description

Linear guide

Technical Field

The present invention relates to a linear guide, and more particularly, to a linear guide capable of supplying lubricant to contact portions of a rail, a slider, and a rolling element over a long period of time.

Background

Conventionally, a linear guide includes a guide rail extending in an axial direction and a slider relatively movably straddling the guide rail, and the slider relatively moves in the axial direction on the guide rail via a plurality of rolling elements (balls) circulating between rolling element rolling grooves formed in the guide rail and the slider. Such linear guides are often used for linear movement mechanisms of various production apparatuses. In order to stably use the linear guide for a long period of time, it is important to supply a sufficient amount of lubricant to the rolling element rolling grooves and the balls and to maintain a good lubrication state.

Patent document 1 describes a linear guide bearing device in which a porous lubricant supply member containing a lubricant is accommodated in a housing, and is attached to an end portion of a slider, and the lubricant is supplied from the lubricant supply member in contact with a rolling element rolling groove of a guide rail.

In patent document 2, a reinforcing plate, a lubricant-containing member, and a side seal are fixed in an overlapping state from the side close to the end cap on the outer side surface of the end cap. The lubricant-containing member is formed in a C-shape conforming to the end cap, and an annular member having an outer diameter larger than an inner diameter of the through hole is fitted into the through hole formed so that an upper portion of the connecting portion is opened, whereby the through hole is expanded, and both sleeve portions are pressed against the guide rail. Further, annular members are also fitted into the through holes that open the outer side surfaces of the two sleeve portions, respectively.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2006-46529

Patent document 2: japanese patent laid-open No. 09-112551

Disclosure of Invention

Technical problem to be solved by the invention

However, in the lubrication unit 100 of patent document 1, as shown in fig. 8, a lubricant supply member 101 containing a lubricant is accommodated in a housing 103 integrally formed with a cylindrical portion 104. The lubricant supply member 101 is fitted into the cylindrical portion 104 of the housing 103 in the recess 102 formed in the upper portion, the upper end portion of the lubricant supply member 101 is pressed and deformed outward in the width direction of the slider, and the rear surface of the sliding portion 105 of the lubricant supply member 101 is pressed by the pressing portions 106 provided on both side surfaces of the housing 103 and is pressed against the rolling element rolling grooves 108 of the guide rail 107, whereby the lubricant is supplied.

However, if the amount of lubricant impregnated into the lubricant supply member 101 decreases with long-term use, the lubricant supply member 101 becomes smaller (contracts) toward the guide rail 107, the pressing force of the cylindrical portion 104 and the pressing portion 106 decreases, and the contact state between the lubricant supply member 101 and the rolling element rolling groove 108 of the guide rail 107 may change, and a sufficient lubrication state may not be maintained. In particular, if the lubricant content of the lubricant supply member 101 is very large, the lubricant supply member 101 may have a large dimensional change due to a decrease in the lubricant, and the above-described problem may occur.

As shown in fig. 9 (a), in the lubrication unit 200 described in patent document 2, the lubricant supply member 201 includes: a substantially U-shaped upper groove 202 formed in an upper portion; a pair of substantially U-shaped transverse grooves 203 formed on both side surfaces; and a sliding portion 208 that is in sliding contact with the rolling element rolling groove 207 of the guide rail 206. An upper ring 204 is provided in the upper groove 202, side rings 205 are provided in each of the pair of lateral grooves 203, and screws, not shown, for fixing the side seals, not shown, and the lubrication unit 200 to the slider are inserted into the side rings 205. Therefore, the relative positions of the side ring 205 and the guide rail 206 are fixed via rolling elements, not shown.

In this case, as shown in fig. 9 (b), when the amount of lubricant impregnated into the lubricant supply member 201 decreases due to long-term use, the size of the lubricant supply member 201 becomes smaller from the state shown by the broken line in the figure as shown by the solid line in the figure. At this time, the position of the side ring 205 is fixed, and therefore the lubricant supply member 201 is deformed in the arrow direction toward the side ring 205. As a result, the contact state between the sliding portion 208 of the lubricant supplying member 201 and the rolling element rolling groove 207 of the guide rail 206 may change, and a sufficient lubrication state may not be maintained.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a linear guide in which a lubricant can be stably supplied for a long period of time by a lubrication means.

Means for solving the problems

The above object of the present invention is achieved by the following structure.

(1) A linear guide, comprising:

a guide rail;

a slider slidably engaged with the guide rail so as to span the guide rail; and

a lubrication unit mounted to an axial end portion of the slider, the lubrication unit having: a lubricant supply member capable of being impregnated with a lubricant; and a housing accommodating the lubricant supply part,

the lubricant supply member is formed in a substantially C-shape and includes: a pair of sleeve portions formed at left and right side surfaces of the rail; and a connecting portion connecting the pair of sleeve portions, the pair of sleeve portions having protrusions capable of sliding contact with the track side raceway surface of the guide rail,

the lubrication unit includes a pair of side pressing units attached to side walls of the housing that are provided on the outer sides of the slider in the width direction with respect to the pair of sleeve portions, and presses the pair of sleeve portions toward the inner sides of the slider in the width direction.

(2) The linear guide according to (1), characterized in that,

each of the side pressing units has: an internal thread portion formed on a side wall of the housing and penetrating in a width direction of the slider; and a screw member that is inserted into the female screw portion and protrudes from the inner surface of the sidewall in the width direction to press the sleeve portion.

(3) The linear guide according to (2), characterized in that,

each of the side pressing units is an elastic member disposed on the inner side surface of the side wall of the case in the width direction and pressing the sleeve.

(4) The linear guide according to any one of (1) to (3), characterized in that,

the lubricant supplying member has a recess formed at an upper position of the guide rail,

the lubrication unit includes an upper pressing unit that is disposed in the recess so as to allow the connecting portion to move in the up-down direction of the slider and press the recess outward in the width direction of the slider.

(5) The linear guide according to any one of (1) to (4), characterized in that,

the protrusion has a chamfer formed at an end edge in the longitudinal direction of the slider.

Effects of the invention

According to the linear guide of the present invention, even if the impregnated lubricant amount becomes smaller with long-term use, the size of the lubricant supplying member becomes smaller, but since the pair of sleeve portions of the lubricant supplying member are pressed inward in the width direction of the slider by the pair of side pressing units, respectively, the force with which the protrusion portion of the lubricant supplying member presses the track-side raceway surface can be ensured. Therefore, the lubrication unit can stably supply the lubricant for a long period of time.

Drawings

Fig. 1 is a perspective view of a linear guide according to the present invention.

Fig. 2 is a perspective view of the slider shown in fig. 1.

Fig. 3 is a partially exploded perspective view of the slider shown in fig. 2.

Fig. 4 is an exploded perspective view of a lubricant supply member and a housing of the lubrication unit shown in fig. 3.

Fig. 5 is a side view for explaining the dimensional relationship between the recess of the lubricant supply member accommodated in the housing and the cylindrical portion of the housing.

Fig. 6 is a side view showing a deformed state of the lubricant supplying member due to a decrease in the lubricant content in the lubrication unit of the first embodiment.

Fig. 7 is a side view showing a lubricant supply member and a housing of the lubrication unit of the second embodiment together with a deformed state of the lubricant supply member.

Fig. 8 is a side view of a conventional lubrication unit.

Fig. 9 (a) is a side view of another conventional lubrication unit, and (b) is a side view showing a state in which a lubricant supply member is deformed due to a reduction in the lubricant content.

Symbol description

10. Linear guide

20. Guide rail

21. 22 track side raceway surface

30. Sliding block

33. 33A lubrication Unit

40 shell

44 cylinder (upper pressing unit)

45. Side wall

49. Internal thread part

50. Lubricant supplying member

51. 52 projection

53. Concave part

58. Sleeve part

59. Connecting part

70 screw parts (side pressing parts)

D outer diameter

D1 Inner width

Detailed Description

The linear guides according to the embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, the vertical direction and the width direction of the slider respectively indicate directions in which the slider is assembled to the guide rail arranged so that the longitudinal direction is horizontal, and the width direction of the slider is a direction perpendicular to the longitudinal direction of the guide rail and the vertical direction of the slider, which is also referred to as a left-right direction (see fig. 1). In addition, the longitudinal direction is also referred to as the axial direction.

(first embodiment)

As shown in fig. 1, the linear guide 10 according to the first embodiment includes: a linear guide rail 20; and a slider 30 assembled so as to span the guide rail 20 and slidably engaged with each other via a plurality of rolling elements (balls), not shown.

The rail 20 has a track-side raceway surface 21 having a substantially semicircular cross section or a substantially gothic arch cross section formed in the axial direction on both side surfaces 23, and a track-side raceway surface 22 having a substantially 1/4 circular arc cross section formed in the axial direction on a ridge line portion where an upper surface 24 of the rail 20 intersects with both side surfaces 23.

As shown in fig. 2 and 3, the slider 30 includes: a slider body 31; end caps 32 attached to both axial end portions of the slider body 31; and a lubrication unit 33 mounted to a further axial end portion of each end cap 32.

The slider body 31 is formed in a substantially C-shape, has a slider-side raceway surface, not shown, facing the track-side raceway surfaces 21, 22 of the guide rail 20 on the inner side surfaces of the two sleeve portions, and has a rolling element return path. The track-side raceway surfaces 21 and 22 and the slider-side raceway surfaces guide rolling elements to be freely rolled, and support a load acting on the slider 30 via the rolling elements. The end cap 32 formed in a substantially C-shape has a curved path, not shown, which communicates the slider-side raceway surface of the slider body 31 with the rolling element return path, and a rolling element circulation path is formed by the track-side raceway surfaces 21 and 22, the slider-side raceway surface, the rolling element return path, and the curved paths at both ends. A plurality of balls are rotatably loaded in the rolling element circulation path.

Referring to fig. 3 and 4, the lubrication unit 33 includes a synthetic resin case 40, a lubricant supply member 50 accommodated in the case 40, and a side seal 60.

The side seal 60 is a substantially C-shaped steel plate that matches the outer shape of the end cap 32, through holes 61 for mounting screws are formed in both sleeve portions 62 of the side seal 60, and through holes 64 for grease pouring nozzles are formed in connecting portions 63 that connect the both sleeve portions 62. The side seal 60 is non-contact with the rail 20, and an elastic body 65 such as urethane rubber containing nitrile rubber or grease is provided inside the C-shaped portion to seal the gap between the slider 30 and the rail 20.

The grease for lubricating the rolling elements and the rolling surface can be injected from the grease injection nozzle into the rolling element circulation path, and in the initial state (the assembled state of the linear guide 10), the rolling element circulation path is filled with the grease.

The lubricant supplying member 50 is formed in a substantially C-shape so as to face the upper surface 24 of the guide rail 20 and both side surfaces 23 including the track side raceway surfaces 21 and 22. That is, the lubricant supply member 50 also includes: a pair of sleeve portions 58 formed at left and right side surface positions of the rail 20; and a connecting portion 59 formed at an upper position of the guide rail 20 and connecting the pair of sleeve portions 58. The lubricant supplying member 50 is formed of a porous body such as rubber, synthetic resin, or the like, a fiber woven body, or the like, to impregnate the lubricant. As the lubricant, mineral oil, synthetic oil, grease, or the like can be used. As the synthetic resin, polyurethane, polyethylene, polypropylene, or the like can be used. As the fiber-woven body, wool felt, polyester fiber, nylon fiber, acrylic fiber, or the like can be used.

From the viewpoint of long-term use, the lubricant impregnation amount of the lubricant supply member 50 is preferably 70% by weight or more. In addition, in view of the strength of the lubricant supplying member 50, the upper limit of the lubricant impregnation amount is preferably 85% by weight or less. For example, as an example of the present embodiment, the lubricant supply member 50 may be given a weight ratio of 15:85 with mineral oil.

A substantially semicircular protrusion 51 is provided protruding from both inner side surfaces of the pair of sleeve portions 58 of the lubricant supplying member 50, and the protrusion 51 is provided to be in sliding contact with the track side raceway surface 21 of the guide rail 20 to supply lubricant. Further, 1/4 arc-shaped protrusions 52 are provided protruding from the inner corners of the pair of sleeve portions 58 and the connecting portion 59, and the protrusions 52 are provided to be in sliding contact with the track side raceway surface 22 of the guide rail 20 to supply lubricant.

Further, a recess 53 that is open at the upper side is formed in the substantially center of the connecting portion 59 of the lubricant supplying member 50. The recess 53 has 2 planes parallel to each other and opposed in the width direction, and is formed in a substantially U shape. The two outer side surfaces of the pair of sleeve portions 58 of the lubricant supplying member 50 extend in the up-down direction and are located on the inner side in the width direction than the two outer side surfaces of the connecting portion 59 so as not to interfere with the side wall 45 of the housing 40 described later.

As shown in fig. 4,

chamfer portions

51a and 52a are formed at end surface edges of the

protrusions

51 and 52 in the thickness direction. The slider 30 of the linear guide 10 may be detached from the guide rail 20 and attached to the guide rail 20 again at the time of assembling work to the mechanical device. At this time, the end surface edges of the

protrusions

51, 52 of the lubricant supplying member 50 may interfere with the edges of the end surfaces of the track side raceway surfaces 21, 22 of the guide rail 20, but by providing the

chamfer portions

51a, 52a, the above-mentioned interference can be prevented, and the assembling workability can be improved.

The case 40 is produced by injection molding a hard resin such as polyacetal or polyamide, and is formed in a substantially C-shape having substantially the same dimensions as the end cap 32. The housing 40 forms a housing portion 43 for housing the lubricant supply member 50 by an outer peripheral wall 41 covering an outer peripheral portion of the housed lubricant supply member 50 and an end wall 42 covering an axial end face of the lubricant supply member 50.

A cylindrical portion 44 as an upper pressing means is formed in the upper portion of the housing portion 43, in the substantially central portion in the lateral direction, continuously with the outer peripheral wall 41 and the end wall 42. A pair of side walls 45 integrally formed with the outer peripheral wall 41 are formed in a laterally symmetrical manner continuously with the end wall 42 at portions facing the pair of sleeve portions 58 on the left and right sides in the accommodating portion 43. The side wall 45 is provided with a screw insertion hole 47 for screw-fixing the lubrication unit 33 to the slider body 31.

The case 40 may be formed by cutting and pressing a metal material such as steel or aluminum.

As shown in fig. 5, a female screw portion 49 penetrating the side wall 45 in the width direction of the slider is formed in the side wall 45 of the housing 40 at a position substantially equal to the protrusion 51 in height. A screw member 70 is inserted into the female screw portion 49, and the screw member 70 presses the sleeve portion 58 by protruding from the inner side surface in the width direction of the side wall 45. Each female screw portion 49 and each screw member 70 constitute a pair of side pressing units.

Then, the cylindrical portion 44 of the housing 40 is fitted into the recess 53 of the lubricant supply member 50, and the screw members 70 are brought into contact with the outer side surfaces of the pair of sleeve portions 58, respectively, so that the lubricant supply member 50 is accommodated in the accommodation portion 43 of the housing 40.

In this way, the housing 40 accommodates the lubricant supply part 50, thereby preventing damage to the lubricant supply part 50 during processing. In particular, when the lubricant impregnation amount of the lubricant supply member 50 is 70 wt% or more, the amount of resin is reduced accordingly, and the strength of the lubricant supply member 50 is reduced, so that it is effective to use the housing 40.

Further, since the outer diameter D of the cylindrical portion 44 is set to be larger than the inner width (left-right width) D1 of the concave portion 53, the cylindrical portion 44 is pressed into the concave portion 53 with an interference in the width direction. As a result, a pressing force in a direction of expanding the inner width of the concave portion 53 acts on the concave portion 53, and as a result, the central portion in the lateral direction of the lubricant supply member 50 (the connecting portion 59) is deformed so as to protrude upward, and as a result, the left and right sleeve portions 58 are also deformed so as to approach each other in the lateral direction.

Further, since the screw member 70 presses the outer side surfaces of the left and right sleeve portions 58, the left and right sleeve portions 58 are deformed so as to approach each other in the left-right direction.

The cylindrical portion 44 applies a pressing force in the width direction to the concave portion 53, but movement in the up-down direction is allowed and is not restricted. Therefore, the connecting portion 59 (lubricant supplying member 50) can slightly move in the up-down direction in the accommodating portion 43 of the housing 40.

In the present embodiment, since the cylindrical portion 44 is provided continuously with the outer peripheral wall 41 of the housing 40, the outer diameter D of the cylindrical portion 44 is determined by the opposing circular arc surfaces.

Therefore, the lubricant is reliably supplied to the track-side raceway surfaces 21, 22 by the

projections

51, 52 of the lubricant supply member 50. The pressing force of the

protrusions

51, 52 against the track-side raceway surfaces 21, 22 is adjusted by the dimensions of the recess 53 and the cylindrical portion 44, and the protruding amount of the screw member 70.

In the case 40 of the present embodiment, the lower surface of the cylindrical portion 44 is cut in the horizontal direction to provide a flat portion 48. Thus, the distance between the upper surface 24 of the rail 20 and the flat surface portion 48, which is the lower surface of the cylindrical portion 44, becomes large, and the width S of the lubricant supply member 50 disposed between the upper surface 24 and the flat surface portion 48 can be enlarged, so that the strength of the lubricant supply member 50 can be improved. In addition, even if the content of the lubricant is increased, the possibility of deformation and breakage of the lubricant supply member 50 is reduced, and handling becomes easy.

In the linear guide 10 configured as described above, when the slider 30 moves on the guide rail 20, the balls in the slider 30 repeatedly circulate in the rolling element circulation path. At this time, the

projections

51 and 52 of the lubricant supplying member 50 are in sliding contact with a part of the track side raceway surfaces 21 and 22 of the guide rail 20, and the lubricant impregnated in the lubricant supplying member 50 oozes out and is automatically supplied to the track side raceway surfaces 21 and 22 and the balls. Thus, even when the amount of grease previously filled in the rolling element circulation path is reduced, a good lubrication state can be maintained, and the linear guide 10 can perform stable and smooth operation for a long period of time.

In addition, when the linear guide 10 is used for a long period of time, the lubricant impregnated in the lubricant supplying member 50 decreases, and as shown in fig. 6, the size of the lubricant supplying member 50 becomes substantially equally smaller from the state shown by the broken line in the figure as shown by the solid line in the figure.

However, even if the size of the lubricant supply member 50 is reduced, by screwing the screw member 70 into the female screw portion 49, the lubricant supply member 50 can be reliably brought into contact with the guide rail 20, and a good lubrication state can be maintained for a long period of time.

In addition, even when the lubrication state is poor and the lubricant supply member 50 at the rail contact portion is worn more than expected, the pressing force of the screw member 70 can be adjusted, so that the lubricant supply member 50 can be reliably brought into contact with the rail raceway surfaces 21, 22.

Further, since the lubricant supplying member 50 is displaceable relative to the housing 40 in the up-down direction, assembly errors between the guide rail 20 and the slider 30 in the up-down direction during assembly of the linear guide 10 can be absorbed, and the lubricant supplying member 50 can be reliably brought into contact with the raceway surfaces 21 and 22. Even when the lubricant supplying member 50 is contracted less by long-term use, the lubricant supplying member 50 can be moved to the optimum vertical position with respect to the guide rail 20 to stably maintain the contact state with the raceway surfaces 21 and 22.

In the present embodiment, the screw member 70 protrudes from the inner side surface in the width direction of the side wall 45 in advance to press the sleeve 58, but in the initial state where the lubricant supply member 50 is assembled to the housing 40, the screw member 70 may be set at a position retracted from the inner side surface in the width direction of the side wall 45, and the side wall 45 of the housing 40 may press the sleeve 58. In addition, when the size of the lubricant supplying member 50 is reduced due to long-term use, by screwing the screw member 70, the lubricant supplying member 50 can be reliably brought into contact with the guide rail 20, and a good lubrication state can be maintained for a long period of time.

(second embodiment)

Fig. 7 is a side view showing a lubricant supply member and a housing as a lubrication unit of the second embodiment together with a deformed state of the lubricant supply member. In the lubrication unit 33A of the present embodiment, the side seal 60 has the same structure as that of the first embodiment, and therefore, the description thereof is omitted.

In the lubrication unit 33A of the second embodiment, a resin ball 80 as an elastic member is provided as a pair of side pressing units in the side wall 45 of the housing 40a, instead of the screw member 70 advancing and retreating from the female screw portion 49 of the first embodiment. The resin balls 80 are formed so as to protrude from the concave portions 46 formed on both inner surfaces of the side wall 45 and press the outer surfaces of the sleeve portions 58.

Therefore, in the present embodiment, when the linear guide 10 is used for a long period of time, the lubricant impregnated into the lubricant supplying member 50 is reduced, and as shown in fig. 7, the size of the lubricant supplying member 50 is reduced substantially uniformly from the state shown by the broken line in the figure to the state shown by the solid line in the figure.

However, even if the lubricant supplying member 50 is reduced in size, the resin balls 80 can press the outer surfaces of the sleeve portions 58, so that the lubricant supplying member 50 can be reliably brought into contact with the guide rail 20, and a good lubrication state can be maintained for a long period of time.

In addition, even when the lubrication state is poor and the lubricant supply member 50 at the rail contact portion is worn more than expected, the resin balls 80 can automatically adjust the pressing force, so that the lubricant supply member 50 can be reliably brought into contact with the rail raceway surface.

In the present embodiment, the elastic member may be provided with a member other than the resin ball as long as the sleeve 58 is pressed even when the lubricant supplying member 50 is small in size.

Other structures and functions are the same as those of the first embodiment.

The present invention is not limited to the above embodiments, and may be modified or improved as appropriate.

For example, the lubrication unit of the above embodiment has a structure including an upper pressing unit and a pair of side pressing units, but the lubrication unit of the present invention is not limited to this, and may have a structure including only a pair of side pressing units without providing an upper pressing unit.

Instead of the balls, rollers (a punch clearance) may be used as the rolling elements.

The present application is based on japanese patent application (japanese patent application 2020-190343) filed on 11/16/2020, the content of which is incorporated herein by reference.

Claims

1. A linear guide, comprising:

a guide rail;

a slider slidably engaged with the guide rail so as to span the guide rail; and

2. The linear guide of claim 1, wherein the linear guide comprises a plurality of guide members,

3. The linear guide of claim 1, wherein the linear guide comprises a plurality of guide members,

4. A linear guide according to any one of claims 1 to 3, characterized in that,

5. The linear guide according to any one of claims 1 to 4, characterized in that,