Linear motion guiding device

Abstract

To provide a linear motion guiding device that can enhance function of high-dust proof and high-hermetic sealability by improving a seal member.SOLUTION: A linear motion guiding device includes a side seal disposed between a slider and a guide rail. The side seal includes: a retainer plate disposed on a slider side; a cover disposed on a far side from the slider relative to the retainer plate; and a seal member nipped between the cover and the retainer plate along a longitudinal direction of the guide rail. The seal member includes: a body retained by the retainer plate; and a lip part extending in a flat shape toward a guide rail side from the body. A space is formed between the retainer plate and the cover and between the body and the lip part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a linear guide device. [Background technology]

[0002] The linear guide device has a roughly annular circulation path that connects a rolling passage for the rolling elements formed between the raceway surface of the guide rail and the raceway surface of the slider body, a return passage for the rolling elements formed in the slider body, and a direction change path for the rolling elements formed in the end cap, and the rolling elements are adapted to circulate within this circulation path.

[0003] In linear guide devices, contact seals such as side seals, inner seals, and under seals are generally used to prevent foreign matter from entering the slider and to prevent lubricant leakage from inside the slider. For example, Patent Document 1 discloses a side seal that is composed of two seal members made of different materials, a retaining plate, and a cover. The lip portions of the two seal members are inclined in opposite directions away from each other. By attaching two seal members to the front and back of the side seal and changing the materials and shapes of the two seal members, it is possible to ensure high dust-proofing and high sealing functions and reduce seal friction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-112398 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the side seal of Patent Document 1, the tip of the seal member protrudes toward the rail in a substantially straight line, so that the seal member does not easily bend when the tip abuts against the rail, and when the seal member goes over the mounting hole of the rail, for example, during reversal motion during reciprocating motion, a gap is generated between the tip of the seal member and the rail, making it difficult to exert a sealing effect. Therefore, in order to sufficiently bend the seal member, it is necessary to lengthen the lip portion and to arrange the gap between the cover and the rail wide, but this causes a problem that the linear guide device becomes large. In addition, Patent Document 1 does not disclose a technology for controlling the minute displacement of the tip of the seal member.

[0006] The present invention has been made in consideration of the problems with the conventional technology, and aims to provide a linear guide device that can enhance the high dust-proofing and high sealing functions by improving the sealing members. [Means for solving the problem]

[0007] The linear guide device of the present invention is A linear guide device comprising a guide rail, a slider, and a plurality of rolling elements, the guide rail and the slider having rolling surfaces disposed opposite each other to form a rolling passage for the rolling elements, and one of the guide rail and the slider performing linear motion relative to the other as the rolling elements roll in the rolling passage, A side seal is disposed between the slider and the guide rail, the side seal includes a retaining plate disposed on the slider side, a cover disposed on a side farther from the slider than the retaining plate, and a seal member disposed between the cover and the retaining plate along a longitudinal direction of the guide rail, The seal member has a main body sandwiched between the retaining plate and the cover, and a lip portion extending from the main body toward the guide rail, A space is formed between the retaining plate and the cover, and between the main body and the lip portion. Effect of the Invention

[0008] According to the present invention, by improving the sealing member, it is possible to provide a linear motion guide device that can enhance the high dust-proof and high sealing functions. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a linear guide device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a view showing the side seal of this embodiment disassembled from the slider. [Diagram 3] FIG. 3 is an exploded view of the side seal. [Figure 4] FIG. 4 is a cross-sectional view of the upper portion of the side seal (cross-section taken along line IV-IV in FIG. 2). [Diagram 5] FIG. 5 is a cross-sectional view similar to FIG. 4, but showing the shape of the lip portion in a free state. [Figure 6] FIG. 6 is a cross-sectional view similar to FIG. 4 of a side seal according to a second embodiment. [Figure 7] FIG. 7 is a cross-sectional view similar to FIG. 4 of a side seal according to a third embodiment. [Figure 8] FIG. 8 is a cross-sectional view similar to FIG. 4 of a side seal according to a fourth embodiment. [Figure 9] FIG. 9 is a front view of the side seal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A linear guide device according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0011] [First embodiment] FIG. 1 shows a perspective view of a linear guide device according to this embodiment. The linear guide device according to this embodiment includes a guide rail 100, a slider 200, and a plurality of rollers (rolling elements) 300. The guide rail 100 and the slider 200 have rolling surfaces 110, 210 that are disposed opposite each other and form a rolling path for the rollers 300.

[0012] The slider 200 has, in the longitudinal direction of the guide rail 100, a slider body 201, a pair of end caps 202 fixed to both ends thereof, and a pair of side seals 20 fixed to both ends thereof. A rolling surface 210 is formed on the slider body 201. The side seals 20 arranged at both ends of the slider 200 in the rail direction seal between the slider 200 and the upper surface and both side surfaces of the guide rail 100 with a seal member.

[0013] The slider 200 also has a return passage 204 for the rollers 300 and a direction change passage 205 that connects the return passage 204 with the rolling passage. The return passage 204 is formed in the slider body 201, and the direction change passage 205 is formed in the end cap 202. The upper surface of the slider 200 is formed with a female thread 206 for attaching a table or the like with screws.

[0014] Mounting holes for grease nipples 400 are formed in the side seal 20 and the end cap 202. Lubricant is introduced from the grease nipple 400 into an oil passage in the end cap 202 to lubricate the linear guide device. The side seal 20 and the end cap 202 are fixed to the slider body 201 using bolts 500. Mounting holes 120 are formed in the guide rail 100 for mounting the guide rail 100 to a mounting portion such as a base with a bolt.

[0015] In this linear guide device, the rolling passage, return passage, and direction change passage form a circulation path for the rolling elements, and as the rollers 300 circulate within this circulation path, one of the guide rail 100 and the slider 200 moves linearly relative to the other.

[0016] Fig. 2 is a diagram showing the side seal of this embodiment in a disassembled state from the slider, and Fig. 3 is a diagram showing the side seal in an disassembled state.

[0017] As shown in Figure 2, the side seal 20 has approximately the same external shape (approximately C-shaped) as the end cap 202 when viewed in the guide rail direction, and includes an upper portion 20a arranged above the guide rail 100, a pair of side portions 20b arranged on each of the left and right sides of the guide rail 100, and a pair of corner portions 20c arranged diagonally above the left and right sides of the guide rail 100.

[0018] 3, the side seal 20 is composed of a seal member 21, a retaining plate 22, and a cover 23. Examples of the material for the seal member 21 include soft resins such as rubber and polyester-based elastomers. Examples of the material for the retaining plate 22 include hard resins such as polyacetal and nylon. Examples of the material for the cover 23 include hard materials such as metal.

[0019] The retaining plate 22 has a plurality of holes 22a for inserting bolts, and the cover 23, which is disposed on the side farther from the slider 200 than the retaining plate 22, also has a plurality of holes 23a for inserting bolts. The side seal 20 is attached to the end cap 202 by sandwiching the seal member 21 between the retaining plate 22 and the cover 23, and then inserting a bolt 500, which has been inserted through the holes 23a and 22a from the outside of the cover 23, into the hole 202a of the end cap 202 and then screwing it into the screw hole of the slider body 201.

[0020] Fig. 4 is a cross-sectional view (IV-IV cross-section in Fig. 2) of the upper portion 20a of the side seal 20, together with the surface of the guide rail 100. Fig. 5 is a cross-sectional view similar to Fig. 4, but shows the shape of the lip portion in a free state, with the guide rail 100 indicated by a dotted line.

[0021] In Fig. 4, the cover 23 is made of a uniform plate material with a thickness t. The seal member 21 is generally U-shaped when viewed in the guide rail direction (see Fig. 3), and has a main body 21a and a lip portion 21b. The main body 21a has a generally rectangular cross section, and has a rectangular groove 21c extending along the periphery of the seal member 21.

[0022] The lip portion 21b extends in a cantilever fashion from the surface of the main body 21a on the guide rail side of the holding plate 22 toward the cover 23. It is preferable that the tip of the lip portion 21b has a shape that gradually becomes thinner.

[0023] The holding plate 22 has a recess 22b corresponding to the main body 21a on the side facing the cover 23. A protrusion 22c corresponding to the rectangular groove 21c of the seal member 21 is formed in the recess 22b.

[0024] When the main body 21a of the seal member 21 is attached to the recess 22b, the raised portion 22c engages with the rectangular groove 21c, thereby preventing the seal member 21 from coming off the retaining plate 22. When the seal member 21 is sandwiched between the retaining plate 22 and the cover 23 in the longitudinal direction of the guide rail 100, as shown in Fig. 4, the main body 21a is disposed farther away from the guide rail 100 than the retaining plate 22 and the cover 23, and is located at a recessed location between the retaining plate 22 and the cover 23. In addition, the lip portion 21b abuts against the guide rail 100 (here, in line contact) to exert a sealing function.

[0025] 5, the lip portion 21b of the seal member 21 in a free state (a state in which it is not in contact with the guide rail 100) has, on the surface on the guide rail 100 side, a first tapered surface 21d on the retaining plate 22 side and a second tapered surface 21e on the cover 23 side, with a boundary P in between. In the free state, the first tapered surface 21d and the second tapered surface 21e each have a tapered shape that decreases in diameter toward the boundary P.

[0026] In the assembled state as shown in Fig. 4, the tip of the lip portion 21b extends beyond the surface (inner surface) 23b of the holding plate 22 side of the cover 23, but does not protrude outside the outer surface 23c facing the inner surface 23b of the cover 23. That is, the tip of the lip portion 21b overlaps with the cover 23 in the axial direction. In other words, the tip of the lip portion 21b is located in the gap between the cover 23 and the guide rail 100. Further, there is a space (clearance) SP between the cover 23 and the holding plate 22, between the upper surface of the lip portion 21b (the surface on the side opposite to the first tapered surface 21d of the lip portion 21b that contacts the guide rail 100) and the main body 21a. Here, if the distance from the cover 23 to the root of the lip portion 21b is A, it is preferable that A > t.

[0027] As shown in Fig. 5, assuming that the gap between the cover 23 and the guide rail 100 is B, it is preferable that B < C with respect to the sealing tightening margin C of the lip portion 21b of the seal member 21. The "sealing tightening margin" refers to the distance from the portion (here, the boundary P) of the seal member 21 that is farthest from the main body 21a in the free state shown in Fig. 5 to the surface of the guide rail 100, and can be obtained from, for example, the design value.

[0028] In the state where the side seal 20 is assembled, the lip portion 21b of the seal member 21 bends, and the first tapered surface 21d partially contacts the guide rail 100 starting from the boundary P. At this time, since the second tapered surface 21e does not contact the guide rail 100, the surface pressure at the boundary P of the first tapered surface 21d becomes the maximum, and the surface pressure decreases as the distance from the boundary P increases. Thereby, the dustproof function can be effectively exerted.

[0029] According to this embodiment, the lip portion 21b of the seal member 21 is protruded toward the guide rail 100 from the retaining plate 22, and a space SP is provided between the lip portion 21b and the main body 21a, thereby increasing the degree of freedom of the lip portion 21b to bend. In addition, by setting the gap B between the cover 23 and the guide rail 100 to be smaller than the seal tightening margin C, the cover 23 can suppress the displacement of the tip of the lip portion 21b so that the lip portion 21b does not move away from the guide rail 100 (does not float). This makes it possible to maintain a good contact state between the lip portion 21b and the guide rail 100, thereby preventing the intrusion of foreign matter into the slider 200 and suppressing the leakage of lubricant.

[0030] [Second embodiment] Fig. 6 is a cross-sectional view of a side seal 20A according to a second embodiment, similar to Fig. 4. In this embodiment, the shape of a seal member 21A is different from that of the first embodiment, and the cover 23 and the retaining plate 22 are the same as those of the first embodiment. Therefore, only the seal member 21A will be described, and redundant description of other configurations will be omitted. The side seal 20A of this embodiment can also be used in the linear guide device shown in Fig. 1.

[0031] 6, in the assembled state, the tip of the lip portion 21Ab extends beyond the surface (inner surface) 23b of the cover 23 facing the retaining plate 22, and further outward beyond the outer surface 23c of the cover 23. Therefore, the boundary P at which the lip portion 21Ab abuts against the guide rail 100 is located farther from the retaining plate 22 than the outer surface 23c. The main body 21a of the seal member 21A is the same as in the first embodiment.

[0032] According to this embodiment, assuming that the thickness of the lip portion 21Ab is the same as in the first embodiment, the distance D between the inner surface 23b of the cover 23 and the lip portion 21Ab is smaller than in the first embodiment, and the extension length of the lip portion 21Ab is longer, making it easier to flex. This makes it possible to maintain a better contact state between the lip portion 21b and the guide rail 100, thereby preventing foreign matter from entering the slider 200 and suppressing leakage of lubricant.

[0033] [Third embodiment] Fig. 7 is a cross-sectional view of a side seal 20B according to a third embodiment, similar to Fig. 4. In this embodiment, the shape of a cover 23B is different from that of the first embodiment, and the seal member 21 and the retaining plate 22 are the same as those of the first embodiment, so only the cover 23B will be described and redundant description of other configurations will be omitted. The side seal 21B of this embodiment can also be used in the linear guide device shown in Fig. 1.

[0034] The cover 23B has a cover body 23Ba having a uniform thickness, and a locking portion 23Bb that is connected to the edge of the cover body 23Ba on the guide rail 100 side and extends toward the retaining plate 22 side. The locking portion 23Bb is assembled so as to enter the space SP between the body 21a and the lip portion 21b of the seal member 21, and the upper surface of the locking portion 23Bb abuts against the lower surface of the body 21a. It is preferable that the tip of the locking portion 23Bb and the base of the lip portion 21b are separated from each other. In addition, it is preferable that the thickness of the locking portion 23Bb becomes thinner toward the tip of the locking portion 23Bb, since it is less likely to interfere with the lip portion 21b.

[0035] According to this embodiment, assuming that the thickness of the lip portion 21b is the same as that of the first embodiment, since the locking portion 23Bb is provided, the distance E between the cover 23B (locking portion 23Bb) and the lip portion 21b is smaller than that of the first embodiment. This makes it possible to maintain a good contact state between the lip portion 21b and the guide rail 100, thereby preventing foreign matter from entering the slider 200 and suppressing leakage of the lubricant.

[0036] [Fourth embodiment] Fig. 8 is a cross-sectional view of a side seal 20C according to a fourth embodiment, similar to Fig. 4. This embodiment differs from the first embodiment only in that an elastic body EB is disposed in the space SP, and redundant explanations of other configurations will be omitted. The side seal 21C of this embodiment can also be used in the linear guide device shown in Fig. 1. The elastic modulus of the elastic body EB is lower than that of the seal member 21.

[0037] According to this embodiment, an elastic body EB is disposed between the main body 21a and the lip portion 21b of the sealing member 21, thereby suppressing deformation of the lip portion 21b. Furthermore, even if there are irregularities on the rail side, the elastic body EB can elastically deform to follow the irregularities, so that a good contact state between the lip portion 21b and the guide rail 100 can be maintained, thereby preventing the intrusion of foreign matter into the slider 200 and suppressing leakage of lubricant.

[0038] (Modification) The above embodiment can be applied to the entire periphery of the side seal 20 that faces the surface of the guide rail 100. However, it can also be partially applied to locations where foreign matter is likely to get mixed in, such as the seal structure in the upper portion 20a of the side seal 20 (the portion indicated by arrow F in FIG. 9) and the seal structure in the lateral portion 20b of the side seal 20 (the portion indicated by arrow G in FIG. 9).

[0039] The present invention is not limited to the above-described embodiment, and the mutual combination of the configurations of the embodiment, and modifications and applications by those skilled in the art based on the description in the specification and well-known techniques are also contemplated by the present invention and are included in the scope of protection sought. Note that the rolling elements are not limited to rollers, and balls, for example, can be used. [Explanation of symbols]

[0040] 20, 20A, 20B, 20C Side seal 21, 21A Sealing material 22 retaining plate, 23, 23B Cover 100 Guide Rail 200 Slider 202 End Cap Around 300 EB Elastic Body SP space

Claims

1. A linear guide device comprising a guide rail, a slider, and a plurality of rolling elements, the guide rail and the slider having rolling surfaces disposed opposite each other to form a rolling passage for the rolling elements, and one of the guide rail and the slider performing linear motion relative to the other as the rolling elements roll in the rolling passage, A side seal is disposed between the slider and the guide rail, the side seal includes a retaining plate disposed on the slider side, a cover disposed on a side farther from the slider than the retaining plate, and a seal member disposed between the cover and the retaining plate along a longitudinal direction of the guide rail, The seal member has a main body sandwiched between the retaining plate and the cover, and a lip portion extending from the main body toward the guide rail, A space is formed between the retaining plate and the cover, and between the main body and the lip portion. A linear motion guide device characterized by the above.

2. A portion of the lip portion is located in a gap between the cover and the guide rail.

2. The linear guide device according to claim 1 .

3. The seal interference of the lip portion is larger than the gap between the cover and the guide rail.

3. The linear guide device according to claim 2 .

4. A tip of the lip portion extends to a position farther from the retaining plate than the cover.

2. The linear guide device according to claim 1 .

5. The cover has an engagement portion that enters the space.

2. The linear guide device according to claim 1 .

6. An elastic body having an elastic modulus lower than that of the sealing member is disposed in the space.

2. The linear guide device according to claim 1 .

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