Linear motion guide unit

Abstract

To provide a linear motion guide unit capable of actualizing maintenance-free operation while reducing the size thereof.SOLUTION: A linear motion guide unit 10 includes a rail, and a slider 21a, the slider 21a including a slide part 31, a first side plate 41, and a second side plate 51a including two second circuit upper side faces 29a, 29b constructing parts of two second circuits 24a, 25a, and opposed to two second circuit lower side faces 28a, 28b, respectively, and arranged to connect the slide part 31 and the first side plate 41, the second side plate 51a being formed of a porous material and including an impregnated part 56 impregnated with lubricating oil, the impregnated part 56 including two second circuit upper side faces 29a, 29b.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a linear guide unit.

Background Art

[0002] A linear guide unit including a lubricating member for achieving a small size and maintenance-free is known (see, for example, Patent Document 1). The lubricating member included in the linear guide unit disclosed in Patent Document 1 is formed as a one-piece integrated structure including a pair of main body portions respectively disposed in recesses formed in end faces on the side opposite to the casing of the end cap, and a pair of connecting portions connecting the pair of main body portions to each other.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Recently, there has been a demand for further miniaturization in linear guide units. Here, when attempting to further miniaturize the linear guide unit disclosed in Patent Document 1, it is necessary to miniaturize each member including the members constituting the lubricating member. Since the lubricating member disclosed in Patent Document 1 has a complicated configuration, it is difficult to miniaturize it. Further, the end cap will also be miniaturized, and assembly using such members will also be difficult. As a result, there is a risk of reduced productivity. Therefore, one of the objectives is to provide a linear guide unit that can achieve maintenance-free while reducing the size.

Means for Solving the Problems

[0005] A linear motion guide unit according to this disclosure comprises a rail having a pair of first track grooves extending longitudinally parallel to each other, a slider straddling the rail so as to be movable relative to the rail and having a pair of second track grooves facing each of the pair of first track grooves, and a plurality of rolling elements. The rail and slider form an annular path through which the plurality of rolling elements circulate. The annular path includes a track made up of the first track grooves and the second track grooves, a first circulation path formed within the slider and parallel to the track, and two second circulation paths formed within the slider and connecting the track and the first circulation path. The slider includes a sliding portion including a first circulation inner surface that constitutes part of the first circulation path and a second raceway groove; a first side plate including a first circulation outer surface that constitutes part of the first circulation path and faces the first circulation inner surface, and two second circulation lower surfaces that constitute part of two second circulation paths; and a second side plate that constitutes part of two second circulation paths and includes two second circulation upper surfaces that face the two second circulation lower surfaces, and is arranged to connect the sliding portion and the first side plate. The second side plate is made of a porous material and includes an impregnated portion impregnated with lubricating oil. The impregnated portion includes two second circulation upper surfaces. [Effects of the Invention]

[0006] According to the above linear motion guide unit, it is possible to achieve maintenance-free operation while miniaturizing the size. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic perspective view showing a linear motion guide unit according to Embodiment 1 of the present disclosure. [Figure 2] Figure 2 is a schematic side view showing the linear motion guide unit shown in Figure 1. [Figure 3] Figure 3 is a schematic cross-sectional view of the linear motion guide unit shown in Figure 1. [Figure 4] Figure 4 is a schematic perspective view showing a slider included in the linear motion guide unit according to Embodiment 1. [Figure 5] Figure 5 is a schematic cross-sectional view of the slider when cut along the cross-section indicated by arrow VV in Figure 4. [Figure 6] Figure 6 is a schematic cross-sectional view of a slider included in the linear motion guide unit in Embodiment 2. [Modes for carrying out the invention]

[0008] [Summary of the Embodiment] The linear motion guide unit of this disclosure comprises a rail having a pair of first track grooves extending longitudinally parallel to each other, a slider straddling the rail so as to be movable relative to the rail and having a pair of second track grooves facing each of the pair of first track grooves, and a plurality of rolling elements. The rail and slider form an annular path through which the plurality of rolling elements circulate. The annular path includes a track made up of the first track grooves and the second track grooves, a first circular path formed within the slider and parallel to the track, and two second circular paths formed within the slider and connecting the track and the first circular path. The slider includes a sliding portion including a first circulation inner surface that constitutes part of the first circulation path and a second raceway groove; a first side plate including a first circulation outer surface that constitutes part of the first circulation path and faces the first circulation inner surface, and two second circulation lower surfaces that constitute part of two second circulation paths; and a second side plate that constitutes part of two second circulation paths and includes two second circulation upper surfaces that face the two second circulation lower surfaces, and is arranged to connect the sliding portion and the first side plate. The second side plate is made of a porous material and includes an impregnated portion impregnated with lubricating oil. The impregnated portion includes two second circulation upper surfaces.

[0009] Recently, there has been a demand for further miniaturization of linear motion guide units. Of course, linear motion guide units are required to be maintenance-free, that is, to ensure smooth sliding of the slider by supplying lubricating oil to the rolling elements over a long period of time. In a slider composed of a casing and a pair of end caps, one method is to incorporate a lubrication unit, i.e., a component that supplies lubricating oil, into the end cap and supply lubricating oil by bringing this lubrication unit into contact with the rolling elements. Another method is to place the lubrication unit in a return path provided inside the slider and arranged parallel to the track path, and supply lubricating oil by bringing the lubrication unit into contact with the rolling elements in this area.

[0010] However, if further miniaturization is pursued in the linear motion guide unit, the lubrication unit incorporated within the end cap and the lubrication unit located in the return path will also become extremely small. This, combined with the large number of parts, will make assembly difficult and reduce productivity. In addition, the amount of lubricating oil that can be held in such an extremely small lubrication unit will be small, and there is a risk that smooth sliding of the slider cannot be ensured over the long term.

[0011] According to the linear motion guide unit of this disclosure, the slider includes a sliding section, a first side plate, and a second side plate. The sliding section includes a first circulation path inner surface that constitutes part of the first circulation path, and a second raceway groove. The first side plate includes a first circulation path outer surface that constitutes part of the first circulation path and faces the first circulation path inner surface, and two second circulation path lower surfaces that constitute part of two second circulation paths. The second side plate each constitutes part of two second circulation paths and includes two second circulation path upper surfaces that face the two second circulation path lower surfaces. The second side plate is also arranged to connect the sliding section and the first side plate. A slider included in a linear motion guide unit with such a configuration consists of a sliding section, a first side plate, and a second side plate, allowing for a relatively simple configuration with a reduced number of parts. This makes it relatively easy to miniaturize each part and make it extremely small while avoiding a decrease in productivity. Therefore, it becomes easy to achieve miniaturization.

[0012] In the linear motion guide unit described above, the second side plate is made of a porous material and includes an impregnated portion impregnated with lubricating oil. The impregnated portion includes two upper surfaces of the second circulation path. With this configuration, when the rolling element passes through the second circulation path, the upper surfaces of the second circulation path included in the impregnated portion can be brought into contact with the rolling element. As a result, lubricating oil can be supplied to the rolling element from the impregnated portion as it passes through the second circulation path. In this case, it is not necessary to specially provide and incorporate a lubrication member for lubrication, as in the linear motion guide unit disclosed in Patent Document 1, for example. Therefore, the complexity of the slider configuration can be avoided. As a result, with such a linear motion guide unit, it is possible to achieve maintenance-free operation while reducing the size.

[0013] In the linear motion guide unit described above, the second side plate may have an impregnated portion throughout its entire surface. By doing so, the structure of the second side plate can be simplified, and a larger area for holding lubricating oil can be secured. Therefore, a large amount of lubricating oil can be held throughout the entire surface of the second side plate, allowing for a longer period of lubrication.

[0014] In the linear guide unit, the width of the rail may be 1 mm or more and 25 mm or less. A linear guide unit including a rail having such a configuration can more reliably achieve miniaturization.

[0015] In the linear guide unit, the porosity of the impregnated portion may be 10% or more and 50% or less. By setting the porosity of the impregnated portion within the above range, the lubricating oil supplied over a long period can be reliably retained in the voids.

[0016] In the linear guide unit, the impregnated portion may be made of resin. By doing so, the impregnated portion having the above configuration can be easily formed. Therefore, productivity can be further improved.

[0017] In the linear guide unit, the impregnated portion may be formed by compressing ultra-high molecular weight polyethylene fine particles. By doing so, such an impregnated portion has good affinity with the lubricating oil, and it is easy to form an impregnated portion having a desired porosity.

[0018] In the linear guide unit, the second side plate may include a coating layer that covers the surface of the impregnated portion. By doing so, it is possible to suppress the evaporation of the lubricating oil retained in the impregnated portion from the surface of the impregnated portion. Therefore, long-term retention of the lubricating oil becomes possible, and the lubricating oil can be supplied over a longer period.

[0019] In the linear guide unit, the coating layer may be composed of grease or wax. According to a coating layer having such a configuration, the affinity with the lubricating oil is also good, and the evaporation of the lubricating oil can be more reliably suppressed.

[0020] In the linear guide unit, the rolling element may be a ball. By doing so, while simplifying the configuration, miniaturization can be achieved.

[0021] [Details of the embodiments of this disclosure] Next, embodiments of the linear motion guide unit of this disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0022] (Embodiment 1) The configuration of the linear motion guide unit in Embodiment 1 of this disclosure will now be described. Figure 1 is a schematic perspective view showing the linear motion guide unit according to Embodiment 1 of this disclosure. Figure 2 is a schematic side view showing the linear motion guide unit shown in Figure 1. Figure 3 is a schematic cross-sectional view of the linear motion guide unit shown in Figure 1. In Figure 1 and the following figures, the X direction indicates the width direction of the linear motion guide unit, which is the short side direction; the Y direction indicates the longitudinal direction of the linear motion guide unit; and the Z direction indicates the thickness direction (height direction) of the linear motion guide unit. The X, Y, and Z directions are orthogonal to each other. Figure 2 is a view from the direction indicated by the arrow Y. Figure 3 is a cross-sectional view when cut by a plane perpendicular to the Z direction, i.e., the XY plane.

[0023] Referring to Figures 1, 2, and 3, the linear motion guide unit 10 in Embodiment 1 includes a rail 11, a slider 21a, and a plurality of balls 20 as rolling elements. The rail 11 is configured to extend straight in the longitudinal direction, which is the Y direction. By including balls 20 as rolling elements, the linear motion guide unit 10 can be miniaturized while simplifying its configuration.

[0024] The rail 11 includes an upper rail end surface 12a and a lower rail end surface 12b spaced apart in the Z direction, a first rail side surface 13a and a second rail side surface 13b spaced apart in the X direction, and a front rail end surface 14a and a rear rail end surface 14b spaced apart in the Y direction. The rail 11 has a pair of first track grooves 15a and 15b extending parallel to each other in the longitudinal direction. The first track groove 15a is provided on the first rail side surface 13a, and the first track groove 15b is provided on the second rail side surface 13b. The first track grooves 15a and 15b are provided on the first rail side surface 13a and the second rail side surface 13b, respectively, so as to be recessed inward from the rail 11 and form recessed grooves. In the Z direction, longitudinally extending projections 16a and 16b are formed between each of the first track grooves 15a and 15b and the upper rail end surface 12a. The first track grooves 15a and 15b are each provided in a position close to the upper end surface 12a of the rail in the Z direction.

[0025] The rail 11 is provided with a plurality of through holes 17a, 17b, and 17c that penetrate in the X direction from the first rail side surface 13a to the second rail side surface 13b. The through holes 17a, 17b, and 17c are spaced apart in the Y direction. The through holes 17a, 17b, and 17c are effectively utilized, for example, when attaching the rail 11 to a predetermined location when using the linear motion guide unit 10.

[0026] Here, the size of this linear guide unit 10 is extremely small. In this embodiment, the width W1 of the rail 11, that is, the length in the X direction between the first rail side surface 13a and the second rail side surface 13b, is, for example, 1 mm. The length in the longitudinal direction of the rail 11, that is, the length in the Y direction, is arbitrarily determined as required, taking into consideration the length W1 and so on. The size of the slider 21a is also determined according to the size of the rail 11 and the requirements. The width W1 of the rail 11 may be between 1 mm and 25 mm. A linear guide unit 10 including a rail 11 with such a configuration can be made more reliably miniaturized.

[0027] Next, the specific configuration of the slider 21a will be described. Figure 4 is a schematic perspective view showing the slider 21a included in the linear motion guide unit 10 according to Embodiment 1. The slider 21a shown in Figure 4 is a diagram showing the linear motion guide unit 10 shown in Figure 1 with the rail 11 and ball 20 removed. Figure 5 is a schematic cross-sectional view of the slider 21a when cut along the cross section indicated by the arrow VV in Figure 4. Note that in Figure 5, the ball 20 is shown for ease of understanding. Figure 5 is a cross-sectional view when cut along a plane perpendicular to the X direction, i.e., the YZ plane.

[0028] Referring in addition to Figures 1 to 3, and also to Figures 4 and 5, the slider 21a is straddled so as to be movable relative to the rail 11. That is, the slider 21a is configured to slide in the Y direction relative to the rail 11. The slider 21a has a pair of second track grooves 18a, 18b facing each of the pair of first track grooves 15a, 15b (see Figure 3 in particular).

[0029] Rail 11 and slider 21a form annular paths 19a and 19b through which multiple balls 20 circulate. The annular paths 19a and 19b are spaced apart in the X direction. In the X direction, annular path 19a is located on the side of the first rail 13a, and annular path 19b is located on the side of the second rail 13b.

[0030] The circular path 19a includes a track path 22a, a first circular path 23a, and two second circular paths 24a and 25a. Track path 22a consists of a first track groove 15a and a second track groove 18a opposite to the first track groove 15a. The first circular path 23a consists of an inner surface 26a and an outer surface 27a opposite to the inner surface 26a. The second circular path 24a consists of a lower surface 28a and an upper surface 29a opposite to the lower surface 28a (see Figure 5 in particular). The second circular path 25a consists of a lower surface 28b and an upper surface 29b opposite to the lower surface 28b. Furthermore, the circular route 19b includes the track route 22b, the first circular route 23b, and two second circular routes 24b and 25b. The track route 22b consists of a first track groove 15b and a second track groove 18b opposite to the first track groove 15b. The first circular route 23b consists of an inner surface 26b and an outer surface 27b opposite to the inner surface 26b. The configuration of the two second circular routes 24b and 25b is the same as that of the two second circular routes 24a and 25a, so their explanation is omitted. The first circular routes 23a and 23b are also called return routes. The second circular routes 24a, 24b, 25a, and 25b are also called direction change routes.

[0031] Here, the slider 21a includes a sliding portion 31, a first side plate (lower side plate) 41, and a second side plate (upper side plate) 51. In this embodiment, the slider 21a is composed of a sliding portion 31, a first side plate 41, and a second side plate 51a.

[0032] First, the configuration of the slide portion 31 will be described. The slide portion 31 is block-shaped. The slide portion 31 includes side wall surfaces 32a, 32b that are spaced apart and exposed in the X direction, and an upper wall surface 33 that is exposed in the Z direction. The upper wall surface 33 is provided with multiple through holes 34a, 34b that penetrate the slide portion 31 in the Z direction. In this embodiment, two through holes 34a, 34b are provided spaced apart in the Y direction.

[0033] Furthermore, the slide portion 31 includes a pair of annular path forming portions 35a and 35b, which are positioned inside the slider 21a at a distance from the rail 11 in the X direction (see Figure 3 in particular). In the X direction, one annular path forming portion 35a is positioned on the side of the first rail 13a, and the other annular path forming portion 35b is positioned on the side of the second rail 13b. One annular path forming portion 35a includes a first circulation path inner surface 26a that constitutes part of the first circulation path 23a, and a second track groove 18a. The other annular path forming portion 35b includes a first circulation path inner surface 26b that constitutes part of the first circulation path 23b, and a second track groove 18b. The slide portion 31 is made of metal.

[0034] Next, the configuration of the first side plate 41 will be described. The first side plate 41 includes a pair of plate-like portions 42a and 42b located at both ends in the longitudinal direction, and a pair of connecting portions 43a and 43b that connect the pair of plate-like portions 42a and 42b, respectively. The plate-like portions 42a and 42b are each formed such that the Y direction is the thickness direction. The plate-like portions 42a and 42b are provided with recesses 44 that are recessed in the Z direction, and the rail 11 is positioned within the recesses 44. The plate-like portion 42a has protruding portions 45a and 45b that project in the X direction so as to catch on the first track grooves 15a and 15b. In addition, the plate-like portions 42a and 42b are provided with a plurality of through holes 46 that penetrate in the Y direction. The connecting portions 43a and 43b are each provided so as to extend in the Y direction. In the X direction, one connecting portion 43a is positioned on the side 13a of the first rail, and the other connecting portion 43b is positioned on the side 13b of the second rail. In the Z direction, the connecting portions 43a and 43b are positioned on the rail 11 side.

[0035] The first side plate 41 includes a first circulation path outer surface 27a that forms part of the first circulation path 23a and faces the first circulation path inner surface 26a, and two second circulation path lower surfaces 28a and 28b that form part of the two second circulation paths 24a and 25a. The first side plate 41 also includes a first circulation path outer surface 27b that forms part of the first circulation path 23b and faces the first circulation path inner surface 26b, and two second circulation path lower surfaces that form part of the two second circulation paths 24b and 25b. The first circulation path outer surface 27a is provided on one connecting portion 43a, and the first circulation path outer surface 27b is provided on the other connecting portion 43b. In this embodiment, the first side plate 41 is made of resin.

[0036] Next, the configuration of the second side plate 51a will be described. The second side plate 51a has a shape that fits between the pair of plate-like portions 42a and 42b of the first side plate 41 and into the space above the pair of connecting portions 43a and 43b. The second side plate 51a is also positioned to cover the sliding portion 31 such that the side wall surfaces 32a and 32b of the sliding portion 31 and the upper wall surface 33 of the sliding portion 31 are exposed. The second side plate 51a is positioned to connect the sliding portion 31 and the first side plate 41.

[0037] The second side plate 51a includes a pair of first portions 52a, 52b spaced apart in the longitudinal direction (Y direction) and a pair of second portions 53a, 53b spaced apart in the short direction (X direction). One of the first portions 52a is plate-shaped with its thickness in the Y direction and is positioned in contact with one plate-shaped portion 42a of the first side plate 41. The other first portion 52b is also plate-shaped with its thickness in the Y direction and is positioned in contact with the other plate-shaped portion 42b of the first side plate 41. The first portions 52a, 52b are also positioned within the through hole 46. The second portions 53a, 53b are shaped to extend in the longitudinal direction and are positioned to connect the first portions 52a, 52b, respectively. When viewed in the Z direction, the upper wall surface 33 of the sliding portion 31 is exposed in the region enclosed by the first portions 52a, 52b and the second portions 53a, 53b. Furthermore, when viewed in the X direction, the side wall surface 32a of the sliding portion 31 is exposed in the region enclosed by the first portions 52a, 52b, the second portion 53a, and the connecting portion 43a of the first side plate 41, and the side wall surface 32b of the sliding portion 31 is exposed in the region enclosed by the first portions 52a, 52b, the second portion 53b, and the connecting portion 43b of the first side plate 41.

[0038] The second side plate 51a each constitutes a part of the two second circulation paths 24a and 25a and includes two upper second circulation path surfaces 29a and 29b that face the two lower second circulation path surfaces 28a and 28b. Similarly, the second side plate 51a each constitutes a part of the two second circulation paths 24b and 25b and includes two upper second circulation path surfaces that face the two lower second circulation path surfaces.

[0039] The second side plate 51a is made of a porous material and includes an impregnated portion 56 impregnated with lubricating oil. In this embodiment, the impregnated portion 56 is made of resin. In this embodiment, the impregnated portion 56 is made by compressing ultra-high molecular weight polyethylene fine particles. For example, Mipelon® (manufactured by Mitsui Chemicals, Inc.) is used as the ultra-high molecular weight polyethylene fine particles. The porosity of the impregnated portion 56 is 10% or more and 50% or less. In this embodiment, the second side plate 51a includes the impregnated portion 56 throughout its entire surface. That is, the second side plate 51a is made up of only the impregnated portion 56. A slider 21a including such a second side plate 51a can be manufactured, for example, as follows. Briefly explaining the manufacturing method of the slider 21a, first the slide portion 31, the first side plate 41, and the second side plate 51a are each manufactured separately. Here, the impregnated portion 56 of the second side plate 51a is impregnated with lubricating oil. Then, the slide portion 31 and the first side plate 41 are combined and attached to the rail 11, and then multiple balls 20, which serve as rolling elements, are inserted into the annular paths 19a and 19b. After that, the first side plate 41 is pushed open and the second side plate 51a is fitted into place to obtain the slider 21a with the above shape.

[0040] Here, the impregnated portion 56 includes the upper surfaces 29a and 29b of the two second circulation paths. That is, the impregnated portion 56 is positioned to contact the ball 20 in the two second circulation paths 24a and 25a.

[0041] A slider 21a included in a linear motion guide unit 10 with this configuration includes the slide portion 31, the first side plate 41, and the second side plate 51a. A slider 21a included in a linear motion guide unit 10 with this configuration consists of the slide portion 31, the first side plate 41, and the second side plate 51a, resulting in a relatively simple configuration with fewer parts. This makes it relatively easy to miniaturize each part and make it extremely small while avoiding a decrease in productivity. Therefore, miniaturization becomes easier.

[0042] In the linear motion guide unit 10 described above, the second side plate 51a is made of a porous material and includes an impregnated portion 56 impregnated with lubricating oil. The impregnated portion 56 includes two upper surfaces 29a and 29b of the second circulation path. With this configuration, when the ball 20 passes through the second circulation paths 24a and 25a, the upper surfaces 29a and 29b of the second circulation path included in the impregnated portion 56 can come into contact with the ball 20. As a result, when the ball 20 passes through the second circulation paths 24a and 25a, lubricating oil can be supplied to the ball 20 from the impregnated portion 56. Therefore, with this linear motion guide unit 10, it is possible to achieve maintenance-free operation while reducing the size.

[0043] In this embodiment, the second side plate 51a includes the impregnated portion 56 throughout its entire surface. Therefore, the structure of the second side plate 51a can be simplified, and a larger area for holding lubricating oil can be secured. Consequently, a large amount of lubricating oil can be held throughout the entire surface of the second side plate 51a, allowing for a longer-term supply of lubricating oil.

[0044] In this embodiment, the void ratio of the impregnated portion 56 is 10% or more and 50% or less. Therefore, the lubricating oil supplied over a long period of time can be reliably retained within the voids.

[0045] In this embodiment, the impregnated portion 56 is made of resin. Therefore, the impregnated portion 56 with the above configuration can be easily formed. Consequently, productivity can be further improved.

[0046] In this embodiment, the impregnated portion 56 is formed by compressing ultra-high molecular weight polyethylene fine particles. Therefore, such an impregnated portion 56 has good affinity with lubricating oil, and it is easy to form an impregnated portion 56 with a desired porosity.

[0047] (Embodiment 2) Next, we will describe another embodiment, Embodiment 2. Figure 6 is a schematic cross-sectional view of the slider included in the linear motion guide unit in Embodiment 2. Referring to Figure 6, the linear motion guide unit in Embodiment 2 has basically the same configuration as in Embodiment 1 and produces the same effects. However, the linear motion guide unit in Embodiment 2 differs from that of Embodiment 1 in the structure of the second side plate.

[0048] Referring to Figure 6, the slider 21b provided in the linear motion guide unit according to Embodiment 2 includes a sliding portion 31, a first side plate 41, and a second side plate 51b. The configuration of the sliding portion 31 and the first side plate 41 is the same as in Embodiment 1, so their description is omitted.

[0049] Here, the second side plate 51b includes a coating layer 59 that covers the surface of the impregnated portion 56. The coating layer 59 is provided on the second side plate 51b, where the impregnated portion 56 is provided throughout, so that the impregnated portion 56 is not exposed to the outside. That is, the impregnated portion 56 is covered by the coating layer 59. The coating layer 59 is made of, for example, grease or wax.

[0050] With a linear guide unit configured in this way, it is possible to suppress the evaporation of lubricating oil held in the impregnated portion 56 from the surface of the impregnated portion 56. Therefore, it becomes possible to retain lubricating oil for a long period of time and supply lubricating oil for a longer period of time.

[0051] In this embodiment, the coating layer 59 is composed of grease or wax. With a coating layer 59 of this configuration, the affinity with lubricating oil is good, and the evaporation of lubricating oil can be suppressed more reliably.

[0052] (Other embodiments) In the above embodiment, the second side plate includes an impregnated portion throughout its entire surface, but it is not limited to this, and only a portion of the second side plate may be impregnated. Specifically, the impregnated portion may be formed in the region including the upper surface of the second circulation path, while the exposed portion of the second side plate may not have an impregnated portion. By doing so, the impregnated portion is not exposed to the outside, and therefore the evaporation of the lubricating oil held in the impregnated portion can be suppressed.

[0053] Furthermore, although the second side plate is made of resin in the above embodiment, it is not limited to this, and for example, the second side plate may be made of metal having voids. The first side plate may also be made of metal.

[0054] In the above embodiment, the rolling element is a ball, but it is not limited to this, and the rolling element may be a roller.

[0055] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the present invention is defined by the claims and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of Symbols]

[0056] 10 Linear guide unit, 11 Rail, 12a Upper end face of rail, 12b Lower end face of rail, 13a Side of first rail, 13b End face of second rail, 14a Front end face of rail, 14b Rear end face of rail, 15a, 15b First track groove, 16a, 16b Protrusion, 17a, 17b, 17c, 34a, 34b, 46 Through hole, 18a, 18b Second track groove, 19a, 19b Ring path, 20 Ball, 21a, 21b Slider, 22a, 22b Track path, 23a, 23b First circulation path, 24a, 24b, 25a, 25b Second circulation path, 26a, 26b Inner side of first circulation path, 27a, 27b Outer side of first circulation path, 28a, 28b Lower side surface of the second circulation path, 29a, 29b Upper side surface of the second circulation path, 31 Sliding part, 32a, 32b Side wall surface, 33 Upper wall surface, 35a, 35b Annular path forming part, 41 First side plate, 42a, 42b Plate-like part, 43a, 43b Connecting part, 44 Recess, 45a, 45b Protruding part, 51a, 51b Second side plate, 52a, 52b First part, 53a, 53b Second part, 56 Impregnated part, 59 Covering layer.

Claims

1. A rail having a pair of first track grooves extending parallel to each other in the longitudinal direction, A slider is straddled so as to be movable relative to the rail and has a pair of second track grooves facing each of the pair of first track grooves, It comprises multiple rolling elements, The rail and the slider form two annular paths through which the plurality of rolling elements circulate. The aforementioned ring road is A track consisting of the first track groove and the second track groove, A first circular path is formed within the slider and runs parallel to the track path, It includes two second circulation paths formed within the slider that connect the track path and the first circulation path, The aforementioned slider is A sliding portion including the inner surface of the first circulation path which constitutes a part of the first circulation path, and the second raceway groove, A first side plate comprising a pair of plate-like portions located at both ends in the longitudinal direction of the slider, each constituting a part of the first circulation path and having the lower surfaces of two of the second circulation paths provided thereon, and a pair of connecting portions extending in the longitudinal direction to connect the pair of plate-like portions at intervals in the short direction which is perpendicular to the longitudinal direction, each having an outer surface of the first circulation path facing the inner surface of the first circulation path, It includes a pair of plate-shaped first portions that constitute a part of two of the second circulation paths, each having an upper surface of the second circulation path facing the lower surface of the two of the second circulation paths, and arranged to contact the pair of plate-shaped portions at a distance in the longitudinal direction, and a pair of second portions that are arranged to connect the first portions at a distance in the short direction and extend in the longitudinal direction, and a second side plate that is arranged between the pair of plate-shaped portions in the longitudinal direction to connect the slide portion and the first side plate, The second side plate is made of a porous material and includes an impregnated portion impregnated with lubricating oil. The impregnated portion is a linear guide unit including two upper surfaces of the second circulation path.

2. The linear motion guide unit according to claim 1, wherein the second side plate includes the entire impregnated portion.

3. The linear motion guide unit according to claim 1 or claim 2, wherein the width of the rail is 1 mm or more and 25 mm or less.

4. The linear motion guide unit according to any one of claims 1 to 3, wherein the void ratio of the impregnated portion is 10% or more and 50% or less.

5. The linear motion guide unit according to any one of claims 1 to 4, wherein the impregnated portion is made of resin.

6. The linear motion guide unit according to claim 5, wherein the impregnated portion is formed by compressing ultra-high molecular weight polyethylene fine particles.

7. The linear motion guide unit according to any one of claims 1 to 6, wherein the second side plate includes a covering layer that covers the surface of the impregnated portion.

8. The linear motion guide unit according to claim 7, wherein the coating layer is composed of grease or wax.

9. The linear motion guide unit according to any one of claims 1 to 8, wherein the rolling element is a ball.

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