JP7552472B2 - Linear guide - Google Patents

Description

The present invention relates to a linear guide, and more specifically, to a linear guide that can supply lubricant to the contact areas of a guide rail, a slider, and rolling elements for a long period of time.

Conventionally, a linear guide comprises a guide rail extending in the axial direction and a slider mounted on the guide rail so as to be movable relative to the guide rail. The slider moves relative to the guide rail in the axial direction via a number of rolling elements (balls) that circulate between rolling element rolling grooves formed in the guide rail and the slider. Such linear guides are widely used in the linear motion mechanisms of various production facilities. In order to use this linear guide stably for a long period of time, it is important to supply a sufficient amount of lubricant to the rolling element rolling grooves and balls to maintain a good lubricated state.

Patent Document 1 describes a linear guide bearing device in which a porous lubricant supplying member containing a lubricant is housed inside a case and attached to the end of a slider, and lubricant is supplied from the lubricant supplying member that contacts the rolling element rolling grooves of a guide rail.
In addition, in Patent Document 2, a reinforcing plate, a lubricant-containing member, and a side seal are fixed to the outer surface of the end cap in a superimposed state from the side closest to the end cap. The lubricant-containing member is formed in a U-shape to match the end cap, and a ring-shaped member with an outer diameter larger than the inner diameter is fitted into a through hole formed at the connecting part with an open upper portion, thereby expanding the through hole and pressing both sleeves against the guide rail. Also, a ring-shaped member is fitted into each of the through holes with the outer surface sides open of both sleeves.

JP 2006-46529 A Japanese Patent Application Publication No. 09-112551

In the lubrication unit 100 of Patent Document 1, as shown in FIG. 15(a), a lubricant supplying member 101 containing a lubricant is housed in a case 103 having a cylindrical portion 104 integrally formed therewith. The cylindrical portion 104 of the case 103 is fitted into a recess 102 formed in the upper portion of the lubricant supplying member 101, and the upper end of the lubricant supplying member 101 is pressed and deformed outward in the width direction of the slider, and the back surface of the sliding portion 105 of the lubricant supplying member 101 is pressed by pressing portions 106 provided on both sides of the case 103, and is pressed against the rolling element rolling groove 108 of the guide rail 107, thereby supplying the lubricant.

However, as shown in FIG. 15(b), when the amount of lubricant impregnated in the lubricant supplying member 101 decreases with long-term use, the dimensions of the lubricant supplying member 101 decrease from the state shown by the dashed line in the figure to the state shown by the solid line in the figure, the pressing force by the cylindrical portion 104 and the pressing portion 106 decreases, and the contact state between the lubricant supplying member 101 and the rolling element rolling groove 108 of the guide rail 107 changes, and there is a risk that sufficient lubrication cannot be maintained. In particular, if the lubricant supplying member 101 contains a very large amount of lubricant, the dimensional change of the lubricant supplying member 101 due to the reduction in lubricant is large, and the above-mentioned problems are more likely to occur.

In the conventional lubrication unit 200 shown in FIG. 16(a), the lubricant supply member 201 includes an approximately U-shaped upper groove 202 formed on the upper portion, a pair of approximately U-shaped lateral grooves 203 formed on both side surfaces, and a sliding portion 208 that slides against a rolling element rolling groove 207 of a guide rail 206. An upper ring 204 is installed in the upper groove 202, and a side ring 205 is installed in each of the pair of lateral grooves 203, and a side seal (not shown) and a screw (not shown) are inserted into the side ring 205 to fix the lubrication unit 200 to the slider. Therefore, the relative positions of the side ring 205 and the guide rail 206 are fixed via the rolling elements (not shown).

In this case, as shown in FIG. 16(b), when the amount of lubricant impregnated in the lubricant supplying member 201 decreases due to long-term use, the dimensions of the lubricant supplying member 201 decrease from the state shown by the dashed line in the figure to the state shown by the solid line in the figure. At that time, since the position of the side ring 205 is fixed, the lubricant supplying member 201 deforms in the direction of the arrow 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 changes, and there is a risk that sufficient lubrication cannot be maintained.

In addition, in Patent Document 2, the lubricant-containing member is pressed by a ring-shaped member fitted into the through hole of the connecting portion, and its position is fixed by two ring-shaped members on both sleeve portions. When the oil in the lubricant-containing member decreases, the dimensions of the lubricant-containing member become smaller. At this time, since its position is fixed by the two ring-shaped members on both sleeve portions, the lubricant-containing member deforms in a direction away from the rolling element rolling groove of the guide rail. This deformation causes the lubricant-containing member to change its contact state with the rolling element rolling groove of the guide rail. As a result, the lubricant application state becomes unstable, and there is a risk that the lubricant state cannot be maintained.

The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide a linear guide in which the lubrication unit can stably supply lubricant over a long period of time.

The above object of the present invention can be achieved by the following configuration.
(1) A linear guide comprising: a guide rail; a slider slidably engaged with the guide rail so as to straddle the guide rail; and a lubrication unit having a lubricant supplying member capable of being impregnated with a lubricant and attached to an axial end of the slider,
the lubricant supplying member includes a first recess formed above the guide rail, a pair of second recesses formed on both left and right side surfaces of the guide rail, and a protrusion capable of slidingly contacting a rail-side raceway surface of the guide rail,
The lubrication unit includes:
an upper pressing means disposed in the first recess so as to allow the first recess to move in the up-down direction of the slider and to press the first recess outward in the width direction of the slider;
a pair of side pressure means disposed in the pair of second recesses so as to permit movement of the pair of second recesses in the width direction of the slider and to press the pair of second recesses downwardly of the slider, respectively;
A linear guide comprising:
(2) The lubrication unit includes the lubricant supplying member and a case that houses the lubricant supplying member,
The linear guide according to (1), wherein the upper pressing means and the pair of side pressing means are provided inside the case.
(3) The upper pressing means is a first cylindrical portion having an outer diameter larger than a width of the first recess,
the pair of side pressing means are second cylindrical portions having an outer diameter equal to or smaller than a width of the pair of second recesses,
The linear guide described in (1) or (2), characterized in that the second cylindrical portion is offset downward from the second recess by more than half the difference between the width of the second recess and the outer diameter of the second cylindrical portion.
(4) The linear guide according to (3), characterized in that a chamfer is provided on the tip side edge of the first and second cylindrical portions constituting the upper pressing means and the pair of side pressing means.
(5) The linear guide according to any one of (1) to (4), wherein the lower surface of the upper pressing means has a flat portion cut out in the horizontal direction.
(6) The linear guide according to any one of (1) to (5), wherein the width direction side surface of the side surface pressing means has a flat portion cut out in the vertical direction.

According to the linear guide of the present invention, the lubricant supplying member capable of being impregnated with the lubricant comprises a first recess formed at an upper position of the guide rail, a pair of second recesses formed at both left and right side positions of the guide rail, and a protrusion capable of slidingly contacting the rail-side track surface of the guide rail. The lubrication unit also comprises an upper pressing means disposed within the first recess to allow the slider in the first recess to move in the up-down direction and to press the first recess outward in the width direction of the slider, and a pair of side pressing means disposed within the pair of second recesses to allow the slider in the width direction of the slider to move in the pair of second recesses and to press the pair of second recesses downwardly, respectively. As a result, even if the amount of impregnated lubricant decreases with long-term use and the dimensions of the lubricant supply member become smaller, the first recess is pressed outward in the width direction of the slider by the upper pressing means, and the pair of second recesses are each pressed downward on the slider by a pair of side pressing means, so the force with which the protrusions of the lubricant supply member press against the rail-side track surface is secured. Therefore, the lubrication unit can stably supply lubricant for a long period of time.

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. 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 supplying member and a case of the lubrication unit shown in FIG. 3 . FIG. 1A is a side view showing the state in which the lubricant supplying member is housed in the case, and FIG. 1B is a side view for explaining the dimensional relationship between a recess of the lubricant supplying member housed in the case and a cylindrical portion of the case. FIG. 11 is a side view of the lubricant supplying member, showing the pressing direction and the displacement direction due to interference with the cylindrical portion of the case. FIG. 6A is a cross-sectional view taken along line X1-X1 in FIG. 6, FIG. 6B is a cross-sectional view taken along line X2-X2 in FIG. 7, FIG. 6C is a cross-sectional view taken along line Y1-Y1 in FIG. 6, and FIG. 4 is a side view showing a deformation state of a lubricant supplying member due to a reduction in the amount of contained lubricant in the lubrication unit of the first embodiment. FIG. FIG. 6 is an enlarged view of a portion X in FIG. 5 . FIG. 11 is a perspective view of a lubricant supplying member and a case of a lubrication unit according to a second embodiment. 12 is an exploded perspective view of a lubricant supplying member and a case of the lubrication unit shown in FIG. 11. 13 is a side view showing a state in which a lubricant supplying member of a lubrication unit according to a modified example of the present invention is housed in a case. FIG. 13 is a side view showing a state in which a lubricant supplying member of a lubrication unit according to another modified example of the present invention is housed in a case. FIG. FIG. 2A is a side view of a conventional lubrication unit, and FIG. 2B is a side view showing a state in which a lubricant supplying member is deformed due to a reduction in the amount of contained lubricant. 1A is a side view of another conventional lubrication unit, and FIG. 1B is a side view showing a state in which a lubricant supplying member is deformed due to a reduction in the amount of contained lubricant.

Below, the linear guide according to each embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the vertical direction and width direction of the slider respectively refer to the directions when the slider is attached to a guide rail arranged with its longitudinal direction horizontal, and the width direction of the slider is the direction perpendicular to the longitudinal direction of the guide rail and the vertical direction of the slider, and is also called the left-right direction.

First Embodiment
As shown in FIG. 1, the linear guide 10 of the first embodiment includes a linear guide rail 20 and a slider 30 that is assembled so as to straddle the guide rail 20 and slidably engages with the guide rail 20 via a plurality of rolling elements (balls) not shown.

On both side surfaces 23 of the guide rail 20, a rail-side track surface 21 having a substantially semicircular or gothic arch-shaped cross section is formed in the axial direction, and on the ridge where the top surface 24 of the guide rail 20 intersects with both side surfaces 23, a rail-side track surface 22 having a substantially quarter-circular arc-shaped cross section is formed in the axial direction.

As shown in Figures 2 and 3, the slider 30 is composed of a slider body 31, end caps 32 attached to both axial ends of the slider body 31, and lubrication units 33 attached to the axial ends of each end cap 32.

The slider body 31 is formed in a roughly U-shape, and has slider-side raceway surfaces (not shown) on the inner surfaces of both sleeves that face the rail-side raceway surfaces 21, 22 of the guide rail 20, as well as a rolling element return path. The end cap 32, also formed in a roughly U-shape, has a curved path (not shown) that connects the slider-side raceway surfaces and the rolling element return path of the slider body 31, and the rail-side raceway surfaces 21, 22, the slider-side raceway surfaces, the rolling element return path, and the curved paths at both ends form a rolling element circulation path. A number of balls are loaded in the rolling element circulation path so that they can roll freely.

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

The side seal 60 is a steel plate in a roughly U-shape that matches the outer shape of the end cap 32, and both sleeves 62 have through holes 61 for mounting screws, while the connecting portion 63 that connects both sleeves 62 has a through hole 64 for a grease nipple. The side seal 60 and the guide rail 20 are not in contact, and an elastic body 65 such as nitrile rubber or polyurethane rubber containing grease is provided on the inside of the U-shape to seal the gap between the slider 30 and the guide rail 20.

The lubricant supplying member 50 is formed in a generally U-shape so as to face the upper surface 24 of the guide rail 20 and both side surfaces 23 including the rail-side track surfaces 21 and 22. The lubricant supplying member 50 is formed of a porous body such as rubber or synthetic resin, a fibrous body, or the like, and is impregnated with a lubricant. Examples of lubricants that can be used include mineral oil, synthetic oil, and grease. Examples of synthetic resins that can be used include polyurethane, polyethylene, and polypropylene. Examples of fibrous bodies that can be used include wool felt, polyester fiber, nylon fiber, and acrylic fiber.

From the viewpoint of long-term use, the amount of lubricant impregnated in the lubricant supplying member 50 is preferably 70% by weight or more. In addition, the upper limit of the amount of lubricant impregnated is preferably 85% by weight or less, taking into consideration the strength of the lubricant supplying member 50. For example, in one example of this embodiment, the lubricant supplying member 50 is molded by mixing polyethylene and mineral oil in a weight ratio of 15:85.

A roughly semicircular protrusion 51 is provided on the inside of both side surfaces of the U-shaped portion of the lubricant supply member 50 to supply lubricant by sliding against the rail-side track surface 21 of the guide rail 20. In addition, a quarter-circular protrusion 52 is provided on the inner corners of both side surfaces and the top surface of the U-shaped portion to supply lubricant by sliding against the rail-side track surface 22 of the guide rail 20.

Furthermore, a first recess 53 that opens upward is formed in approximately the center of the upper end of the lubricant supply member 50. Also, a second recess 54 that is approximately U-shaped and opens to the side is formed on both outer surfaces of the lubricant supply member 50. The first recess 53 is formed in an approximately U-shape with two parallel flat surfaces that face each other in the width direction, and the second recess 54 is formed in an approximately U-shape with two parallel flat surfaces that face each other in the up-down direction, and the corners 54a between the two flat surfaces and the vertical surface are curved.

As shown in FIG. 4, chamfered portions 51a, 52a are formed on the end surface edges of the protrusions 51, 52 in the thickness direction, respectively. The slider 30 of the linear guide 10 may be removed from the guide rail 20 and reattached to the guide rail 20 during assembly to a machine device. In this case, the end surface edges of the protrusions 51, 52 of the lubricant supply member 50 may interfere with the edges of the end surfaces of the rail-side track surfaces 21, 22 of the guide rail 20. However, by providing the chamfered portions 51a, 52a, this interference is prevented, improving assembly workability.

The case 40 is manufactured by injection molding a hard resin such as polyacetal or polyamide, and is formed in a roughly U-shape with roughly the same size as the end cap 32. The case 40 forms a storage section 43 for storing the lubricant supply member 50 by an outer peripheral wall 41 that covers the outer periphery of the lubricant supply member 50 contained therein, and an end wall 42 that covers the axial end face of the lubricant supply member 50.

A first cylindrical portion 44 serving as upper pressing means is formed contiguous to the outer peripheral wall 41 and the end wall 42 at approximately the center in the left-right direction at the top of the storage portion 43. Second cylindrical portions 45 serving as side pressing means are formed symmetrically on both the left and right sides of the storage portion 43 at approximately the center in the height direction, contiguous to the outer peripheral wall 41 and the end wall 42. The second cylindrical portions 45 are provided with screw insertion holes 47 for fixing the lubrication unit 33 to the slider body 31 with screws.
The case 40 may be made by cutting or pressing a metal material such as steel or aluminum.

Then, as shown in FIG. 5, the first cylindrical portion 44 of the case 40 is fitted into the first recess 53 of the lubricant supply member 50, and the second cylindrical portions 45 are fitted into the pair of second recesses 54, respectively, to store the lubricant supply member 50 in the storage portion 43 of the case 40.

In this way, the case 40 can store the lubricant supply member 50 and prevent the lubricant supply member 50 from being damaged during handling. In particular, when the amount of lubricant impregnated in the lubricant supply member 50 becomes 70% by weight or more, the amount of resin decreases accordingly, and the strength of the lubricant supply member 50 decreases, so the use of the case 40 is effective.

As shown in FIG. 5(b), the outer diameter D3 (see FIG. 8(a)) of the first cylindrical portion 44 is set to be larger than the inner width (left-right width) D1 of the first recess 53, so that the first cylindrical portion 44 and the first recess 53 interfere with each other by T1. That is, the first cylindrical portion 44 is pressed into the first recess 53 with a clamping margin T1 (= (D3-D1)/2). The clamping margin T1 between the cylindrical portion 44 and the recess 53 is set to about 0.1 to 0.5 mm.

On the other hand, the second cylindrical portion 45 and the second recess 54 interfere with each other only on the lower side with the tightening margin T2, and a gap T3 is formed on the upper side. That is, the second cylindrical portion 45 presses the second recess 54 downward with the tightening margin T2, while escaping from the upper surface of the second recess 54 by the gap T3. For this reason, in this embodiment, the outer diameter D3' of the second cylindrical portion 45 (see FIG. 8C) is set to be equal to or smaller than the inner width (vertical width) D1' of the second recess 54, and the second cylindrical portion 45 is offset downward from the second recess 54 by more than 1/2 the difference between the inner width D1' of the second recess 54 and the outer diameter D3' of the second cylindrical portion 45. In FIG. 5B, the dimension T4 represents the offset amount (T4>(D1'-D3')/2) between the vertical middle position of the second recess 54 and the center of the second cylindrical portion 45. The interference T2 between the cylindrical portion 45 and the recess 54 is set to about 0.1 to 0.5 mm. The interference T2 and the gap T3 may be such that T3≧T2, and it is preferable that T3 is the same as or slightly larger than T2.
For example, in one example of this embodiment, the first cylindrical portion 44 is pressed into the first recess 53 of the lubricant supply member 50 with a clamping margin T1 = 0.3 mm, and the second cylindrical portion 45 is arranged in the second recess 54 with a clamping margin T2 = 0.2 mm and a gap T3 = 0.2 mm.

The first cylindrical portion 44 applies a pressing force to the first recess 53 in the width direction, but vertical movement is permitted and not restricted. The second cylindrical portion 45 applies a pressing force to the second recess 54 in the downward direction, but vertical movement is permitted and not restricted.
In addition, in this embodiment, the first cylindrical portion 44 and the second cylindrical portion 45 are provided continuously with the outer peripheral wall 41 of the case 40, and therefore the outer diameter D3 of the first cylindrical portion 44 and the outer diameter D3' of the second cylindrical portion 45 are respectively given by opposing arc surfaces.

As the first cylindrical portion 44 is pressed into the first recess 53 with a clamping margin T1, a pressing force acts on the first recess 53 in a direction that widens the inner width of the first recess 53 (in the direction of arrow A), as shown in Figure 7. As a result, as shown in Figure 5 (a), the central portion in the left-right direction is deformed to become convex upward, and the left and right sleeve portions 55 are also deformed to approach each other in the left-right direction.
In addition, as the second cylindrical portion 45 presses against the underside of the second recess 54 with the clamping margin T2, a pressing force acts on the underside of the second recess 54 in a direction that widens the inner width of the second recess 54 (in the direction of arrow B), and the lower parts of the left and right sleeve portions 55 deform so as to approach each other in the left-right direction.

Therefore, due to interference between the first and second cylindrical portions 44, 45 and the first and second recesses 53, 54, the upper protrusion 52 of the lubricant supply member 50 is displaced in the width direction (arrow C direction) and downward (arrow D direction) and presses the rail side track surface 22 of the guide rail 20 diagonally downward. In addition, the lower protrusion 51 of the lubricant supply member 50 is displaced in the width direction (arrow C direction) and upward (arrow D direction) and presses the rail side track surface 21 of the guide rail 20 diagonally upward.

Therefore, the lubricant is reliably supplied to the rail side track surfaces 21, 22 by the protrusions 51, 52 of the lubricant supply member 50. The pressing force of the protrusions 51, 52 against the rail side track surfaces 21, 22 is adjusted by the dimensions of the first and second recesses 53, 54 and the first and second cylindrical portions 44, 45.

As shown in FIG. 8, in the case 40, the outer diameters D3, D3' of the first and second cylindrical portions 44, 45 are larger than the inner widths D1, D1' of the first and second recesses 53, 54. Therefore, when the lubricant supplying member 50 is housed in the case 40, the interference T1 between the first cylindrical portion 44 and the first recess 53 is, and the interference T2 between the second cylindrical portion 45 and the second recess 54 is, (D3'-D1')/2.

Therefore, the first cylindrical portion 44 is pressed into the planar side surfaces of the first recess 53 with an interference T1, and the contacting portion of the first recess 53 releases lubricant to relieve stress and contracts in the width direction of the slider. Also, the second cylindrical portion 45 presses the planar lower surface of the second recess 54 with an interference T2, and the contacting portion of the second recess 54 releases lubricant to relieve stress and contracts in the up-down direction of the slider. Therefore, the lubricant supplying member 50 is restrained by the case 40 in the up-down direction and the width direction of the slider, so that the posture of the lubricant supplying member 50 can be stabilized.
Therefore, the planar underside of the first recess 53 and the planar side of the second recess 54 are not constrained, but the contacting portions of the first recess 53 and the second recess 54 can further stabilize the posture of the lubricant supplying member 50 even when the lubricant supplying member 50 contracts.

As shown in FIG. 8(a), the first cylindrical portion 44 has chamfered portions 46 at an angle a at the tip edge of the cylindrical portion 44, specifically, at two locations in the width direction of the tip edge of the cylindrical portion 44. Therefore, the distance D2 of the tip edge of the cylindrical portion 44 is smaller than the inner width D1 of the first recess 53, making it easy to attach the first cylindrical portion 44 to the first recess 53.

As shown in FIG. 8(c), the second cylindrical portion 45 also has chamfered portions 46 with an angle a' at the tip edge of the cylindrical portion 45, specifically, at two locations above and below the tip edge of the cylindrical portion 45. The outer diameter D3' of the second cylindrical portion 45 is set to be equal to or smaller than the inner width D1' of the second recess 54, but since a tightening margin T2 is generated between the lower surface of the second cylindrical portion 45 and the second recess 54, the provision of the chamfered portions 46 makes it easier to attach the second cylindrical portion 45 to the second recess 54. Note that the distance D2' of the tip edge of the cylindrical portion 45 is smaller than the inner width D1' of the second recess 54.

This makes it easy to attach the lubricant supplying member 50 to the case 40. The chamfer angles a, a' are preferably 15 to 45 degrees, and the chamfer amounts D3-D2, D3'-D2' are preferably about 0.5 to 2 mm.
In the case 40 of this embodiment, the chamfer angles a and a' are 30°, and the chamfer amounts D3-D2 and D3'-D2' are 1 mm.

In addition, as shown in FIG. 5(a), the case 40 of this embodiment has a cylindrical first cylindrical portion 44 with the lower surface thereof cut out horizontally to provide a flat portion 48. This increases the distance between the upper surface 24 of the guide rail 20 and the flat portion 48, which is the lower surface of the first cylindrical portion 44, and allows the width S of the lubricant supply member 50 disposed between the upper surface 24 and the flat portion 48 to be increased, improving the strength of the lubricant supply member 50. Furthermore, even if the lubricant content is increased, the risk of deformation or breakage of the lubricant supply member 50 is reduced, making it easier to handle.

In the linear guide 10 configured in this manner, when the slider 30 moves on the guide rail 20, the balls in the slider 30 repeatedly circulate within the rolling element circulation path. At this time, the protrusions 51, 52 of the lubricant supplying member 50 slide against parts of the rail-side track surfaces 21, 22 of the guide rail 20, and the lubricant impregnated in the lubricant supplying member 50 seeps out and is automatically supplied to the rail-side track surfaces 21, 22 and the balls. This allows the linear guide 10 to operate stably and smoothly for a long period of time.

In addition, when the linear guide 10 is used for a long period of time, the amount of lubricant impregnated in the lubricant supply member 50 decreases, and as shown in Figure 9, the dimensions of the lubricant supply member 50 decrease almost uniformly from the state shown by the dashed line in the figure to the state shown by the solid line in the figure.

Due to this change in dimensions, the width dimension of the first recess 53 and the vertical dimension of the second recess 54 also become smaller. Since the first cylindrical portion 44 is pressed into the first recess 53, the width dimension of the first recess 53 does not change, and the pressing force of the first cylindrical portion 44 on the first recess 53 increases. As a result, the left and right sleeve portions 55 are further deformed to approach each other in the left-right direction, and in combination with the contraction of the vertical dimension of the second recess 54, the upper surface of the second recess 54 tries to displace toward the second cylindrical portion 45. However, in this embodiment, due to the gap T3 between the upper surface of the second recess 54 and the second cylindrical portion 45 set before contraction, even after contraction, the gap between the upper surface of the second recess 54 and the second cylindrical portion 45 is maintained small, or is pressed with a small tightening margin, and a tightening margin is also secured between the lower surface of the second recess 54 and the second cylindrical portion 45.

Therefore, even if the lubricant supplying member 50 shrinks, the quarter-arc-shaped protrusion 52 of the lubricant supplying member 50 contacts the rail-side track surface 22 of the guide rail 20 and maintains the force pressing the rail-side track surface 22 diagonally downward. Also, the approximately semicircular protrusion 51 contacts the rail-side track surface 21 of the guide rail 20 and maintains the force pressing the rail-side track surface 21 diagonally upward. In other words, even if the dimensions of the lubricant supplying member 50 change, the lubricant is supplied stably from the lubricant supplying member 50 for a long period of time.

In addition, when the dimensions of the lubricant supply member 50 are reduced, stress also acts on the corners 54a of the second recess 54, but because the corners 54a are formed in a curved shape, this stress concentration is alleviated.

In particular, the lubricant supply member 50 of this embodiment has a high lubricant content of 85% by weight, so the amount of lubricant lost, i.e., the dimensional change (reduction), is also large, making the effects of the present invention more pronounced.

Figure 10 is an enlarged view of the main part showing the contact state between the rail-side raceway surface and the protrusions of the lubricant supply member. In the lubrication unit 33 of this embodiment, the contact area between the rail-side raceway surface 21, 22 and the protrusions 51, 52 of the lubricant supply member 50 is limited to the vicinity of the contact area with the ball, as shown by the highlighted line F in the figure. Specifically, the radius R1 of the protrusions 51, 52 of the lubricant supply member 50 is slightly smaller than the radius R2 of the rail-side raceway surface 21, 22, and is 95 to 99% of the radius R2. Alternatively, the protrusions 51, 52 of the lubricant supply member 50 may be provided with partial protrusions, and only the protrusions may be brought into contact with the rail-side raceway surface 21, 22.

As a result, a gap of about 0.1 to 0.5 mm is formed between the lubricant supply member 50 and the parts other than the vicinity of the contact part with the ball, and there is no contact, so the sliding resistance with the lubricant supply member 50 is reduced, and the energy consumption of the drive motor can be reduced. In addition, since strict dimensional control is not required for the parts other than the contact part with the rail side raceway surfaces 21 and 22, the manufacture of the lubricant supply member 50 becomes easier. In addition, there is a gap of several tens of μm between the lower flank of the approximately semicircular rail side raceway surface 21 and the ball, and since there is no contact with the ball, this part also does not come into contact with the protrusions 51 and 52 of the lubricant supply member 50.

As described above, the linear guide 10 of this embodiment has a lubricant supply member 50 that can be impregnated with lubricant, and is provided with a lubrication unit 33 attached to the axial end of the slider 30. The lubricant supply member 50 includes a first recess 53 formed at an upper position of the guide rail 20, a pair of second recesses 54 formed at both left and right side positions of the guide rail 20, and protrusions 51, 52 that can slide on the rail-side track surfaces 21, 22. The lubrication unit 33 includes a first cylindrical portion 44 disposed in the first recess 53 so as to allow the first recess 53 to move in the vertical direction of the slider 30 and to press the first recess 53 outward in the width direction of the slider 30, and a pair of second cylindrical portions 45 disposed in the pair of second recesses 54 so as to allow the pair of second recesses 54 to move in the width direction of the slider 30 and to press the pair of second recesses 54 downwardly of the slider 30. As a result, even if the amount of impregnated lubricant decreases with long-term use and the dimensions of the lubricant supply member 50 become smaller, the first recess 53 is pressed outward in the width direction of the slider 30 by the first cylindrical portion 44, and the pair of second recesses 54 are each pressed downward on the slider 30 by the pair of second cylindrical portions 45, so the force pressing the protrusions 51, 52 of the lubricant supply member 50 against the rail-side track surfaces 21, 22 is secured, and the supply of lubricant is maintained for a long period of time.

The lubrication unit 33 also includes a lubricant supply member 50 and a case 40 that houses the lubricant supply member 50. The first cylindrical portion 44 and the pair of second cylindrical portions 45 are provided inside the case 40. This allows for a reduction in the number of parts compared to when the case 40 and the cylindrical portions 44, 45 are constructed as separate parts, and also allows for protection of the lubricant supply member 50.

Furthermore, since the outer diameter D3 of the first cylindrical portion 44 is larger than the width D1 of the first recess 53, the cylindrical portion 44 can press the first recess 53 in the width direction.
In addition, the outer diameter D3' of the pair of second cylindrical portions 45 is larger than the width D1' of the pair of second recesses 54, and the second cylindrical portion 34 is offset downward with respect to the second recesses 54 by more than half the difference between the width D1' of the second recesses 54 and the outer diameter D3' of the second cylindrical portion 45, so that the pair of second cylindrical portions 45 can press the pair of second recesses 54 downward.

In addition, the first cylindrical portion 44 and the pair of second cylindrical portions 45 have chamfered portions 46 at their tip edges, so that the first cylindrical portion 44 and the pair of second cylindrical portions 45 can be easily inserted into the first recess 53 and the pair of second recesses 54.

In addition, the lubricant supply member 50 is impregnated with 70% or more by weight of lubricant, so it can steadily supply lubricant for a long period of time.

In addition, the lower surface of the first cylindrical portion 44 has a flat portion 48 cut out horizontally, so that the width S of the lubricant supply member 50 disposed between the upper surface 24 of the guide rail 20 and the flat portion 48 can be increased, thereby improving the strength of the lubricant supply member 50.

Second Embodiment
Fig. 11 is a perspective view of a lubricant supplying member and a case of a lubrication unit of the second embodiment, and Fig. 12 is an exploded perspective view of the lubricant supplying member and the case. In a lubrication unit 33A of this embodiment, a pressing plate 40A is used instead of the case 40 of the first embodiment. Since other parts are similar to the lubrication unit 33 of the first embodiment, the same or corresponding parts are denoted by the same or corresponding reference numerals, and the description will be simplified or omitted.

The pressure plate 40A of this embodiment is also manufactured by injection molding a hard resin such as polyacetal or polyamide, and is formed in a roughly U-shape with roughly the same size as the end cap 32. The pressure plate 40A may also be manufactured by cutting or pressing a metal material such as steel or aluminum.

The pressure plate 40A of this embodiment does not have the outer peripheral wall 41 of the case 40 of the first embodiment, and is composed of a plate portion 42A formed in a generally U-shape of approximately the same size as the end cap 32, a first cylindrical portion 44 as an upper pressure means formed to protrude from the plate portion 42A at positions corresponding to the first and second recesses 53, 54 of the lubricant supply member 50, and a pair of second cylindrical portions 45 as side pressure means.

The lubricant supplying member 50 is assembled by fitting the first and second cylindrical portions 44, 45 into the first and second recesses 53, 54, respectively, and closely contacting the plate portion 42A. According to the lubrication unit 33A of the present embodiment, the volume of the lubricant supplying member 50 can be increased by the amount of the outer peripheral wall 41, and the lubricant supplying member 50 can hold more lubricant.
The other configurations and operations are similar to those of the first embodiment.

The present invention is not limited to the above-described embodiments, and can be modified and improved as appropriate.
13, for example, the side surface in the width direction of the cylindrical second cylindrical portion 45 may be cut out in the vertical direction to provide a flat portion 49. This increases the distance between the side surface 23 of the guide rail 20 and the flat portion 49 of the second cylindrical portion 45, and the width T of the lubricant supplying member 50 disposed between the side surface 23 and the flat portion 49 can be increased, further improving the strength of the lubricant supplying member 50. This reduces the risk of deformation or breakage of the lubricant supplying member 50 even if the lubricant content is increased, making it easier to handle.

14, other flat surfaces 44a cut out along the vertical direction may be formed on both widthwise side surfaces of the first cylindrical portion 44, and other flat surfaces 45a cut out along the horizontal direction may be formed on both top-bottom side surfaces of the second cylindrical portion 45. This makes it possible to stabilize the position of the lubricant supplying member 50 even when the lubricant supplying member 50 contracts.
The configurations shown in FIGS. 13 and 14 can be applied to either the first or second embodiment, or can be applied in combination with both.

10 Linear guide 20 Guide rail 21, 22 Rail-side raceway surface 30 Slider 33, 33A Lubrication unit 40 Case 40A Pressing plate 44 First cylindrical portion (upper pressing means)
45 Second cylindrical portion (side pressing means)
46 Chamfered portion 50 Lubricant supplying member 51, 52 Protrusion 53 First recess 54 Second recess D1, D1' Inner width (left-right width of first recess, up-down width of second recess)
D3, D3' Outer diameter

Claims (6)

A linear guide comprising: a guide rail having rail-side raceway surfaces formed on both left and right side surfaces ; a slider slidably engaged across the guide rail; and a lubrication unit having a lubricant supplying member capable of being impregnated with a lubricant and attached to an axial end of the slider,
The lubricant supplying member is formed in a substantially U-shape so as to face the upper surface of the guide rail and the left and right side surfaces including the rail-side raceway surface,
the lubricant supplying member is provided with a first recess formed above the guide rail and opening upward , a pair of second recesses formed on both left and right side surfaces of the guide rail and opening to the side opposite the guide rail , and a protrusion capable of sliding contact with the rail -side raceway surface of the guide rail,
The lubrication unit includes:
an upper pressing means disposed in the first recess so as to allow the first recess to move in the up-down direction of the slider and to press the first recess outward in the width direction of the slider;
a pair of side pressure means disposed in the pair of second recesses so as to permit movement of the pair of second recesses in the width direction of the slider and to press the pair of second recesses downwardly of the slider, respectively;
A linear guide comprising: The lubrication unit includes the lubricant supplying member and a case that houses the lubricant supplying member,
2. The linear guide according to claim 1, wherein the upper pressing means and the pair of side pressing means are provided inside the case. the upper pressing means is a first cylindrical portion having an outer diameter larger than a width of the first recess,
the pair of side pressing means are second cylindrical portions having an outer diameter equal to or smaller than a width of the pair of second recesses,
The linear guide according to claim 1 or 2, characterized in that the second cylindrical portion is offset downward from the second recess by more than half the difference between the width of the second recess and the outer diameter of the second cylindrical portion. The linear guide according to claim 3, characterized in that the tip side edges of the first and second cylindrical parts constituting the upper pressing means and the pair of side pressing means are provided with chamfered parts. The linear guide according to any one of claims 1 to 4, characterized in that the lower surface of the upper pressing means has a flat portion cut out in the horizontal direction. The linear guide according to any one of claims 1 to 5, characterized in that the widthwise side of the side pressing means has a flat portion cut out in the vertical direction.

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