Linear motion guide device and method for manufacturing same

Abstract

The present invention provides a linear motion guide device in which, provided that a vertical center plane CP is defined to be a plane passing through the widthwise center of a slider body and a longitudinal axis line of a guide rail, a horizontal reference plane HP is defined to be a plane orthogonal to the vertical center plane CP and passing through a straight-portion centerline of a rolling path, and a vertical reference plane VP is defined to be a plane parallel to the vertical center plane CP and intersecting a chamfered portion, the surface of the chamfered portion lies on a locus of revolution centered on a point O2 shifted along the horizontal reference plane HP so as to be farther away from a first orbital plane than the groove-bottom center O1 of the first orbital plane in a cross section perpendicular to the straight-portion centerline, and the locus of revolution has a minimum radius that is greater than a groove-bottom radius r of the first orbital plane.

Description

Linear guide device and manufacturing method thereof

[0001] The present invention relates to a linear guide device and a manufacturing method thereof.

[0002] Linear guide devices, which guide objects linearly while allowing rolling elements such as rollers and balls to circulate endlessly inside, are one of the important machine elements that have a significant impact on the motion accuracy of semiconductor manufacturing equipment, ultra-precision processing machines, ultra-precision measuring instruments, etc.

[0003] The linear guide device comprises a guide rail and a slider body. The guide rail is provided with rail-side rolling element raceway grooves. The slider body is provided with slider-side rolling element raceway grooves facing the rail-side rolling element raceway grooves, and is supported by the guide rail so as to be movable in the axial direction via the rolling of multiple rolling elements disposed in rolling paths formed between the slider-side rolling element raceway grooves and the rail-side rolling element raceway grooves. The linear guide device further comprises a rolling element return path provided in the slider body so as to be approximately parallel to the rolling path, and direction change paths provided in end caps attached to both ends of the slider body in the moving direction, which connect the rolling path and the rolling element return path.

[0004] When the rolling elements of a linear motion guiding device circulate endlessly through the rolling passage, direction change passage, and rolling element return passage, periodic micro-vibrations (hereinafter referred to as rolling element passing vibrations) occur, which greatly affect the motion accuracy of the aforementioned equipment. Rolling element passing vibrations occur when a rolling element, which is rolling in the rolling passage (loaded area) while being loaded by preload or external load, releases the load as it leaves the loaded area and enters the rolling element circulation path (unloaded area), or conversely, when it takes on a new load as it enters the loaded area from the unloaded area.

[0005] To suppress this rolling element passing vibration, inclined surfaces called crownings are provided at both ends of the slider-side rolling element raceway grooves that form the rolling passage. The crownings allow the load fluctuations that accompany the rolling elements entering and leaving the load zone to occur gradually, thereby reducing the rolling element passing vibration.

[0006] Patent Document 1 discloses a linear guide bearing comprising: a first crowning having a curved surface shape, inclined portions provided at both ends of the slider-side rolling element raceway groove, formed with a large radius of curvature so that the slope continues from the slider-side rolling element raceway groove and becomes gentler; a second crowning adjacent to the first crowning, extending toward the inner peripheral surface of the direction change path, with a steeper slope than the first crowning and shorter in axial length than the first crowning; and an inclined surface provided between the second crowning and the end face of the slider body, which is more inclined than the first crowning and second crowning.

[0007] Japanese Patent Application Publication No. 2008-133837

[0008] In the slider body of Patent Document 1, in cross sections obtained by cutting the slider-side rolling element raceway grooves along a plane that passes through the axis of the slider-side rolling element raceway groove and extends in the vertical direction, horizontal direction, etc., the shapes of the ends of the cross sections are uniform. Therefore, it is necessary to form the first crowning, second crowning, and inclined surface in a common shape in all cross sections, which may cause early wear of the processing tools and increase the manufacturing cost of the linear guide bearing.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a linear guide device and a manufacturing method thereof that are low cost and can ensure smooth ball movement while mitigating impact forces regardless of the behavior of the ball entering the track surface.

[0010] The linear guide device of the present invention is a linear guide device comprising: a guide rail; a slider arranged so as to move relatively to the guide rail in a longitudinal direction; and a plurality of rolling elements arranged so as to be able to roll along a rolling path formed between the guide rail and the slider, wherein the slider comprises: a slider body having raceway grooves arranged opposite to the raceway grooves of the guide rail to form the rolling paths of the rolling elements, and return paths for the rolling elements; and an end cap having a direction change path connecting the return path and the rolling path, wherein the raceway groove of the slider body has a first raceway surface on the central side of the rolling path and a second raceway surface on the end side of the rolling path, and the second raceway surface has a first inclined surface extending from the first raceway surface to the end face of the slider body, and a chamfered portion extending to the end face of the slider body without contacting the first inclined surface, When a plane passing through the widthwise center of the slider body and the longitudinal axis of the guide rail is defined as a vertical center plane CP, a plane perpendicular to the vertical center plane CP and passing through the center line of the straight portion of the rolling path is defined as a horizontal reference plane HP, and a plane parallel to the vertical center plane CP and intersecting the chamfered portion is defined as a vertical reference plane VP, the surface of the chamfered portion, in a cross section perpendicular to the center line of the straight portion, is on a rotation locus whose center is a point O2 shifted along the horizontal reference plane HP with respect to the center line O1 of the straight portion of the rolling path so as to be separated from the first raceway surface, and the minimum radius of the rotation locus is larger than the groove bottom radius r of the first raceway surface.

[0011] The manufacturing method of the linear guide device of the present invention is a manufacturing method of a linear guide device comprising: a guide rail; a slider arranged so as to move relatively to the guide rail in a longitudinal direction; and a plurality of rolling elements arranged so as to be rollable along a rolling path formed between the guide rail and the slider, wherein the slider comprises: a slider body having raceway grooves arranged opposite to the raceway grooves of the guide rail to form the rolling paths of the rolling elements, and return paths for the rolling elements; and an end cap having a direction change path connecting the return path and the rolling path, wherein the raceway groove of the slider body has a first raceway surface on the central side of the rolling path and a second raceway surface on the end side of the rolling path, and the second raceway surface has a first inclined surface extending from the first raceway surface to the end face of the slider body, and a chamfered portion extending to the end face of the slider body without contacting the first inclined surface, The chamfered portion is formed by rotating a grinding tool or cutting tool having a tapered rotational locus around a processing axis O2 that is translated parallel to a center line O1 of the straight portion of the rolling path so as to move the tool away from the first raceway surface, and bringing the tool close to the second raceway surface along the processing axis O2, thereby removing a part of the first inclined surface.

[0012] According to the present invention, it is possible to provide a linear guide device and a manufacturing method thereof that are low cost and can ensure smooth ball movement while mitigating impact forces regardless of the behavior of the ball entering the track surface.

[0013] FIG. 1 is a perspective view showing a linear guide device according to a first embodiment of the present invention. FIG. 2 is a front view of the slider body of the linear guide device of FIG. 1, viewed from the longitudinal direction of the guide rail. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 2. FIG. 4(a) is a perspective view showing a part of the slider body cut away, and FIG. 4(b) is an enlarged perspective view of a part of the leg shown by the chain line in FIG. 4(a). FIG. 5(a) is a view of a part of the leg in FIG. 4, viewed in the direction of arrow VA. FIG. 5(b) is a view of the raceway groove, taken along a vertical reference plane VP, which is perpendicular to the horizontal reference plane HP and passes through the leg in the vicinity of both ends of the raceway groove in the width direction. FIG. 5(c) is a view showing a cross section of the end of the raceway groove cut along the horizontal reference plane HP. FIG. 5(d) is a view showing a cross section of the end of the raceway groove cut along the vertical reference plane VP. Fig. 6 is a schematic diagram showing a cross section similar to Fig. 5(b) according to a comparative example, together with rolling elements. Fig. 7 is a schematic diagram showing a cross section similar to Fig. 5(b) according to the first embodiment, together with rolling elements. Fig. 8(a) is a diagram similar to Fig. 5(a) according to a second embodiment, Fig. 8(b) is a view of the raceway grooves, taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the legs in the vicinity of both widthwise ends of the raceway grooves, Fig. 8(c) is a cross section of the end of the raceway groove taken along the horizontal reference plane HP, and Fig. 8(d) is a cross section of the end of the raceway groove taken along the vertical reference plane VP. Fig. 9(a) is a view similar to Fig. 5(a) according to a third embodiment, Fig. 9(b) is a view of the leg portion shown in Fig. 9(a) taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg portion near both widthwise ends of the raceway groove, Fig. 9(c) is a view showing a cross section of the end of the raceway groove taken along the horizontal reference plane HP, Fig. 9(d) is a view showing a cross section of the end of the raceway groove taken along the vertical reference plane VP. Fig. 10(a) is a view similar to Fig. 5(a) according to a fourth embodiment, Fig. 10(b) is a view of the leg portion shown in Fig. 10(a) taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg portion near both widthwise ends of the raceway groove, Fig. 10(c) is a view showing a cross section of the end of the raceway groove taken along the horizontal reference plane HP, and Fig. 10(d) is a view showing a cross section of the end of the raceway groove taken along the vertical reference plane VP.FIG. 11(a) is a view similar to FIG. 5(a) relating to a fifth embodiment, FIG. 11(b) is a view of the track groove taken by cutting the leg shown in FIG. 11(a) along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg near both ends of the track groove in the width direction, FIG. 11(c) is a view showing a cross section of the end of the track groove taken along the horizontal reference plane HP, and FIG. 11(d) is a view showing a cross section of the end of the track groove taken along the vertical reference plane VP.

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification, terms indicating directions (upward, downward, etc.) refer to the respective directions in Figure 2 unless otherwise specified. Furthermore, the term "longitudinal direction" refers to the longitudinal direction of the guide rail or slider.

[0015] First Embodiment FIG. 1 is a perspective view showing a linear guide device according to a first embodiment of the present invention. FIG. 2 is a front view of the slider body of the linear guide device of FIG. 1 as seen from the longitudinal direction of the guide rail, with the end caps omitted. FIG. 3 is a cross-sectional view taken along III-III in FIG. 2, with the cage 4 and cage groove 10Ba omitted. In FIG. 2, a plane passing through the widthwise center of the slider body 2A and the longitudinal axis of the guide rail 1 is defined as a vertical center plane CP, and a plane perpendicular to the vertical center plane CP and passing through the center lines O1 of the linear portions of a pair of rolling paths 13A arranged on both sides of the guide rail 1 is defined as a horizontal reference plane HP. Furthermore, a plane shifted from the center lines O1 of the linear portions of the rolling paths 13A toward the first upper raceway surface and perpendicular to the horizontal reference plane HP is defined as a vertical reference plane VP. The vertical reference plane VP is a plane parallel to the vertical center plane CP and intersects with the second and third inclined planes described below. Although details will be described later, the configuration of each part will be described using the vertical reference plane VP and horizontal reference plane HP corresponding to one of the rolling paths 13A.

[0016] A slider 2 having a substantially U-shaped cross section is mounted along a linearly extending guide rail 1 having a substantially rectangular cross section so as to be movable in the longitudinal direction of the guide rail 1. At the ridge where both left and right side surfaces 1a, 1a in the width direction of the guide rail 1 intersect with the top surface 1b, track grooves 10A, 10A consisting of recessed grooves having a cross section shaped like a quarter of a circle are formed along the longitudinal direction.

[0017] Furthermore, raceway grooves 10B, 10B each consisting of a recessed groove having a substantially semicircular cross section are formed along the longitudinal direction at approximately the center in the vertical direction of both left and right widthwise side surfaces 1a, 1a of the guide rail 1. Furthermore, at the groove bottoms of the raceway grooves 10B, 10B, a cage groove 10Ba (wire groove) that accommodates a part of the cage 4 and guides the cage 4 during movement of the slider 2 is formed along the longitudinal direction between both ends of the movement area of ​​the slider 2 (for example, between both ends in the longitudinal direction of the guide rail 1). The cross section of the cage groove 10Ba is, for example, substantially rectangular.

[0018] The slider 2 is made up of a flat body 7 facing the upper surface 1b of the guide rail 1 and two legs 6, 6 extending downward from both the left and right sides of the body 7 and facing the side surface 1a, and the angle between the body 7 and the legs 6, 6 is approximately right angles, so that the cross section of the slider 2 is approximately U-shaped. Furthermore, the slider 2 is attached movably relative to the guide rail 1, with the guide rail 1 sandwiched between the legs 6, 6.

[0019] The slider 2 comprises a slider body 2A and end caps 2B, 2B detachably attached to both ends (longitudinal ends) of the slider body 2A. Furthermore, side seals 5, 5 are attached to both ends of the slider 2 (longitudinal outer end surfaces of each end cap 2B) and slide against the outer surfaces (upper surface 1b and side surfaces 1a, 1a) of the guide rail 1 to seal the portions of the opening of the gap between the guide rail 1 and the slider 2 that face the longitudinal end surfaces, and under seals 8, 8 are attached to the bottom of the slider 2 to seal the portions of the opening of the gap between the guide rail 1 and the slider 2 that face the underside of the slider 2. These side seals 5, 5 and under seals 8, 8 prevent foreign matter from entering the gap from the outside and lubricant from leaking from the gap to the outside.

[0020] Furthermore, raceway grooves 11A, 11A, 11B, 11B (hereinafter, these may be collectively referred to as 11) consisting of recessed grooves with a substantially semicircular cross section that face raceway grooves 10A, 10A, 10B, 10B (hereinafter, these may be collectively referred to as 10) of the guide rail 1 are formed at the corners and approximately the center in the vertical direction of the inner surfaces of both the left and right legs 6, 6 of the slider body 2A. Furthermore, rolling paths 13A, 13A, 13B, 13B (hereinafter, these may be collectively referred to as 13) with a substantially circular cross section are formed between the raceway groove 10 of the guide rail 1 and the raceway groove 11 of the slider 2, and these rolling paths extend in the longitudinal direction.

[0021] A plurality of rolling elements 3 (balls) are loaded in the rolling passage 13 so as to be able to roll freely while being held by a cage 4, and the slider 2 is guided by the guide rail 1 and is able to move in the longitudinal direction via the rolling of the rolling elements 3 in the rolling passage 13. The cage 4 is formed of, for example, a wire, and holds the rolling elements 3 to prevent them from falling off the slider 2 before it is assembled to the guide rail 1.

[0022] The number of raceway grooves 10, 11 provided on the guide rail 1 and the slider 2 is not limited to two rows on one side, but may be, for example, one row on one side, or three or more rows. The cross-sectional shape of the raceway grooves 10, 11 may be an arc shape consisting of a single arc as described above, but may also be a substantially V-shape (Gothic arc-shaped groove) formed by combining two arcs with different centers of curvature.

[0023] Furthermore, the slider 2 is provided with return passages 14A, 14A, 14B, 14B (hereinafter, the reference numeral 14 may be used to refer to these collectively) which are through-holes with a substantially circular cross section that run parallel to the rolling passage 13 and penetrate the slider 2 in the longitudinal direction at the upper and lower parts of the thick portions of the left and right legs 6, 6 of the slider body 2A (see Figures 2 and 3).

[0024] The end cap 2B is made of, for example, a molded product of a resin material and has a generally U-shaped cross section similar to the slider body 2A. Furthermore, on both the left and right sides of the back surface of the end cap 2B (the surface that abuts against the slider body 2A), two arc-shaped, circular cross-sectional direction change paths 15 are formed (upper and lower) (see FIG. 3). When the end cap 2B is attached to the slider body 2A with fastening members such as screws, the direction change paths 15 connect the rolling path 13 and the return path 14. The cross-sectional shape of the direction change paths 15 is shown schematically in FIG. 3.

[0025] The return path 14 and the direction change paths 15 at both ends constitute a rolling element transport path 16 that transports and circulates the rolling elements 3 from the end point of the rolling path 13 to the start point, and the rolling path 13 and the rolling element transport path 16 constitute a substantially circular circulation path (see Figure 3). This substantially circular circulation path is formed in two levels, one above the other, on both the left and right sides of the guide rail 1.

[0026] When the slider 2 moves longitudinally along the guide rail 1, the rolling elements 3 loaded in the rolling path 13 move in the same direction as the slider 2 relative to the guide rail 1 while rolling within the rolling path 13. When the rolling elements 3 reach the end point of the rolling path 13, they are scooped up from the rolling path 13 and sent to the direction change path 15. Having entered the direction change path 15, the rolling elements 3 change direction and are introduced into the return path 14, and pass through the return path 14 to reach the opposite direction change path 15, where they change direction again and return to the start point of the rolling path 13. The rolling elements 3 repeat this circulation within the circulation path indefinitely, allowing the slider 2 to move smoothly along the guide rail 1.

[0027] FIG. 4(a) is a perspective view showing a cutaway portion of the slider body 2A, and FIG. 4(b) is an enlarged perspective view of a portion of the leg 6 indicated by the chain line in FIG. 4(a). FIG. 5(a) is a view of a portion of the leg 6 in FIG. 4 as viewed in the direction of arrow VA. FIG. 5(b) is a view of the raceway groove 11A as viewed by cutting the leg 6 shown in FIG. 5(a) along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg 6 near both widthwise ends of the raceway groove 11A. The vertical reference plane VP is located on the raceway groove 11A side of the center line O1 of the straight portion of the rolling path 13A (the same applies to the following embodiments). FIG. 5(c) is a view showing a cross section of the end of the raceway groove 11A cut along the horizontal reference plane HP. FIG. 5(d) is a view showing a cross section of the end of the raceway groove 11A cut along the vertical reference plane VP, along with the rotation trajectory of a cutting tool (or grinding tool).

[0028] The shapes of the ends of the raceway grooves 11A and 11B will be described with reference to the drawings. Hereinafter, the raceway groove 11A will be described as the upper raceway groove, and the raceway groove 11B will be described as the lower raceway groove. Furthermore, the term "first raceway surface" refers to at least one of the first upper raceway surface and the first lower raceway surface, and the term "second raceway surface" refers to at least one of the second upper raceway surface and the second lower raceway surface.

[0029] 4(a) and 4(b), the upper raceway groove 11A has a first upper raceway surface 11Aa on the central side of the slider body 2A and a second upper raceway surface 11Ab on the end side of the slider body 2A. The first upper raceway surface 11Aa and the second upper raceway surface 11Ab are each bounded by a horizontal reference plane HP (see FIG. 5) that passes through the groove bottom, with the portion above the horizontal reference plane HP referred to as the upper flank and the portion below the horizontal reference plane HP referred to as the lower flank. The upper flank and the lower flank are symmetrical with respect to the horizontal reference plane HP.

[0030] The first upper raceway surface 11Aa has a uniform cross section perpendicular to the longitudinal direction. The center line of the cylindrical space formed by the first upper raceway surface 11Aa and the raceway groove 10A (see FIG. 2) of the guide rail 1 is defined as the center line O1 of the straight portion of the rolling path 13A. The center line O1 of the straight portion of the rolling path 13A is located within the horizontal reference plane HP (FIG. 5(a)). In contrast, the second upper raceway surface 11Ab is formed so that the cross section perpendicular to the longitudinal direction varies partially.

[0031] 5, the second upper track surface 11Ab has a first upper inclined surface 11Ac extending along the straight portion center line O1, a second upper inclined surface 11Ad tangent to the first upper inclined surface 11Ac and formed above it, and a third upper inclined surface 11Ae tangent to the first upper inclined surface 11Ac and formed below it. The second upper inclined surface 11Ad and the third upper inclined surface 11Ae form a chamfered portion. The first upper inclined surface 11Ac has a symmetrical shape with respect to a horizontal reference plane HP, and the second upper inclined surface 11Ad and the third upper inclined surface 11Ae each have a shape symmetrical with respect to the horizontal reference plane HP. Here, when simply referring to the first inclined surface, it refers to at least one of the first upper inclined surface and the first lower inclined surface described later, when simply referring to the second inclined surface, it refers to at least one of the second upper inclined surface and the second lower inclined surface described later, and when simply referring to the third inclined surface, it refers to at least one of the third upper inclined surface and the third lower inclined surface described later.

[0032] As shown in FIG. 5B, the first upper inclined surface 11Ac is connected to the first upper raceway surface 11Aa, while the second upper inclined surface 11Ad and the third upper inclined surface 11Ae are spaced apart from the first upper raceway surface 11Aa in the longitudinal direction. Specifically, the width of the first upper inclined surface 11Ac when viewed in a direction perpendicular to the horizontal reference plane HP is uniform near the first upper raceway surface 11Aa and gradually narrows from the vicinity of the first upper raceway surface 11Aa toward the end of the slider body 2A, forming a tapered shape when viewed in the direction of FIG. 5B. On the other hand, the second upper inclined surface 11Ad and the third upper inclined surface 11Ae are formed in a substantially triangular shape when viewed in the direction of FIG. 5B, starting at a position a predetermined distance from the first upper raceway surface 11Aa and gradually widening toward the end of the slider body 2A.

[0033] The first upper inclined surface 11Ac starts at a position a distance L1 from the end face (longitudinal end) 2Aa of the slider body 2A (leg portion 6) and terminates at the end face 2Aa. The distance L1 is the longitudinal length of the first upper inclined surface 11Ac. When the diameter of the rolling element 3 is Da, it is preferable that L1 = 1.0 × Da to 2.0 × Da.

[0034] As shown in Fig. 5(c), the first upper inclined surface 11Ac has a crowning shape that moves away from the center line O1 (vertical reference plane VP) of the straight portion of the rolling path 13A (upward in Fig. 5(c)) as it moves away from the first upper raceway surface 11Aa. The crowning shape is an arc shape with a radius of curvature R1 in a cross section of Fig. 5(c) that includes the horizontal reference plane HP.

[0035] On the other hand, as shown in FIG. 5(d), the second upper inclined surface 11Ad begins at a position a distance L2 from the end face 2Aa of the slider body 2A (leg portion 6) and terminates at the end face 2Aa. When the longitudinal length of the first upper inclined surface 11Ac is L1, it is preferable that L1 > L2. If L2 is longer than L1, the load-bearing function of the upper raceway groove 11A and the crowning function of the first upper inclined surface 11Ac may be impaired, and the axial depth of cut into the blank (material) of the slider body 2A during machining may increase. This raises concerns about increased lead time and increased load on the tool due to reduced radial depth of cut. In contrast, by satisfying L1 > L2, the axial depth of cut into the blank of the slider body 2A during machining can be reduced without interfering with the functions of the upper raceway groove 11A and the first upper inclined surface 11Ac.

[0036] The second upper inclined surface 11Ad has a chamfered shape that moves away from the horizontal reference plane HP (upward in FIG. 5(d)) as it moves away from the first upper track surface 11Aa. The chamfered shape is preferably an arc shape with a radius of curvature R2 in a cross section of FIG. 5(d) that includes the vertical reference plane VP. However, in this embodiment, R2 = ∞, that is, the chamfered shape is a straight line in the cross section of FIG. 5(d).

[0037] In the cross section shown in Figure 5(d), the intersection of the first upper inclined surface 11Ac and the second upper inclined surface 11Ad is preferably a point of discontinuity. Specifically, assuming that the cross section shown in Figure 5(d) is a two-dimensional coordinate system, the surface shape of the first upper inclined surface 11Ac is represented by a curve CL1, the surface shape of the second upper inclined surface 11Ad is represented by a curve C2, and the intersection point between the first upper inclined surface 11Ac and the second upper inclined surface 11Ad is represented by P1, if the slope (differential value) of the tangent to the curve CL1 at the intersection point P1 is different from the slope (differential value) of the tangent to the curve CL2 at the intersection point P1, the curves CL1 and CL2 are discontinuous at the intersection point P1, and the intersection point P1 is referred to as a point of discontinuity. Preferably, the intersection point P1 is the apex of a convex portion of the second upper raceway surface 11Ab that protrudes toward the center line O1 of the straight portion.

[0038] The shape of the third upper inclined surface 11Ae is the same as that of the second upper inclined surface 11Ad except that it is symmetrical with respect to the horizontal reference plane HP, and therefore description thereof will be omitted.

[0039] 4(a) and 4(b), the lower raceway groove 11B has a first lower raceway surface 11Ba on the center side of the slider body 2A and a second lower raceway surface 11Bb on the end side of the slider body 2A, which are parallel to the upper raceway groove 11A. The first lower raceway surface 11Ba and the second lower raceway surface 11Bb are each bounded by a horizontal reference plane HP (see FIG. 2) at the groove bottom, with the portion above the horizontal reference plane HP referred to as the upper flank and the portion below the horizontal reference plane HP referred to as the lower flank. The upper flank and the lower flank are symmetrical with respect to the horizontal reference plane HP.

[0040] The first lower raceway surface 11Ba has a uniform cross section perpendicular to the longitudinal direction, whereas the second lower raceway surface 11Bb is formed so that the cross section perpendicular to the longitudinal direction varies from part to part.

[0041] The second lower raceway surface 11Bb has a first lower inclined surface 11Bc extending along the horizontal reference plane HP, a second lower inclined surface 11Bd formed above the first lower inclined surface 11Bc, and a third lower inclined surface 11Be formed below the first lower inclined surface 11Bc. The second lower inclined surface 11Bd and the third lower inclined surface 11Be are symmetrical with respect to the horizontal reference plane HP. Note that the lower raceway groove 11B has a similar configuration to the upper raceway groove 11A, and therefore its description will be omitted. Furthermore, the shapes of the other ends of the upper raceway groove 11A and the lower raceway groove 11B are also similar to those described above, and therefore their description will be omitted.

[0042] (Effects of the present embodiment) Fig. 6 is a schematic diagram showing a cross section similar to Fig. 5(b) according to a comparative example, together with the rolling elements. Fig. 7 is a schematic diagram showing a cross section similar to Fig. 5(b) according to the present embodiment, together with the rolling elements, but the center line O1 of the straight portion of rolling passage 13A is shifted in the direction perpendicular to the paper surface. Here, the explanation will be given using rolling passage 13A as an example, but the same applies to rolling passage 13B.

[0043] In contrast to this embodiment, the slider body of the comparative example does not have a second raceway surface, and the cylindrical first upper raceway surface 11Aa directly intersects with the end face 2Aa. Other configurations of the comparative example are the same as those of this embodiment.

[0044] For example, due to the influence of centrifugal force and vibrations when passing through the direction change path 15 (see FIG. 3 ) in the end cap 2B, the center of the rolling element 3 may be misaligned with the center line O1 of the straight portion of the rolling path 13A when it enters the rolling path 13A from the direction change path 15. In this case, the amount of misalignment between the center of the rolling element 3 and the center line O1 of the straight portion of the rolling path 13A is defined as the eccentricity e. Because the diameter of the rolling element 3 is slightly smaller than the diameter of the rolling path 13A, if the eccentricity e is smaller than half the diameter difference (diameter of the rolling path 13A - diameter of the rolling element 3), the rolling element 3 can smoothly enter the rolling path 13A. However, if the eccentricity e exceeds half the diameter difference, the rolling element 3 may collide with the edge of the rolling path 13A in the direction of entry, which may result in noise generation or damage to the rolling element 3.

[0045] In contrast, according to this embodiment, the first upper inclined surface 11Ac having a crowning shape is formed at the end of the rolling passage 13A in the approach direction. Therefore, even in a state in which the rolling element 3 is eccentric in the horizontal direction by an eccentricity amount e that exceeds half of the diameter difference, the rolling element 3 entering from the direction change path 15 will come into oblique contact with the first upper inclined surface 11Ac (see FIG. 5(c) ) having an outwardly convex shape with a curvature radius R1, and then roll and be guided to the first upper raceway surface 11Aa. This suppresses large changes in Hertzian stress, thereby suppressing the generation of noise and damage to the rolling element 3 and ensuring smooth movement of the rolling element 3.

[0046] On the other hand, as shown in Figure 7, there are cases where the rolling element 3 enters eccentrically in the vertical direction with an eccentricity amount e that exceeds half of the diameter difference. In such cases, the first upper inclined surface 11Ac alone may hinder the smooth entry of the rolling element 3. In contrast, in this embodiment, the second upper inclined surface 11Ad and the third upper inclined surface 11Ae are formed as chamfered portions having a drop amount d2 above and below the first upper inclined surface 11Ac near the end of the second upper raceway surface 11Ab in the entry direction.

[0047] Therefore, even when a rolling element 3 that is eccentric in the vertical direction by a relatively large eccentricity amount e enters, it will roll after coming into oblique contact with the second upper inclined surface 11Ad or the third upper inclined surface 11Ae, which have an outwardly convex shape with a curvature radius R2, and then be guided from the first upper inclined surface 11Ac to the first upper raceway surface 11Aa. This reduces the impact force on the slider body 2A, making it possible to suppress noise generation and damage to the rolling element 3, and further ensuring smooth movement of the rolling element 3.

[0048] The lower raceway groove 11B has the same configuration as the upper raceway groove 11A, and therefore exerts the same effects.

[0049] (Method for machining the first upper raceway surface and the second upper raceway surface) Next, a method for machining the first upper raceway surface 11Aa will be described. When grinding the first upper raceway surface 11Aa, first, a groove similar to the first upper raceway surface 11Aa is formed in a blank of the slider body 2A by cutting or the like. Then, the center and end portions of the upper raceway groove 11A are ground using a grinding tool that rotates around the center line O1 of the straight portion of the rolling path 13A. This forms the first upper raceway surface 11Aa and the first upper inclined surface 11Ac.

[0050] After forming the first upper raceway surface 11Aa and the first upper inclined surface 11Ac, a separate cutting tool (or grinding tool) TL is used to perform chamfering to form the second upper inclined surface 11Ad and the third upper inclined surface 11Ae. The cutting tool TL has a conical (tapered) rotation path as shown by the chain lines in Figures 5(a) and 5(d). The maximum diameter of the rotation path is greater than the vertical width of the first upper raceway surface 11Aa.

[0051] Specifically, as shown in Figure 5(a), a machining axis O2 is set within the horizontal reference plane HP, which is moved parallel to the center line O1 of the straight portion of the rolling path 13A so as to move away from the upper raceway groove 11A. Then, while rotating the cutting tool TL around the machining axis O2, the cutting tool TL is brought close to the first upper inclined surface 11Ac along the machining axis O2 to perform grinding so as to remove a portion of the first upper inclined surface 11Ac (top and bottom ends). As a result, the second upper inclined surface 11Ad is ground, and at the same time, the third upper inclined surface 11Ae is ground.

[0052] That is, in a cross section perpendicular to the straight portion center line O1 (a cross section parallel to FIG. 5A ), the surfaces of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, which are chamfered portions, are on a rotation locus centered at a point (machining axis) O2 that is shifted along the horizontal reference plane HP relative to the groove bottom center (straight portion center line O1) of the first upper raceway surface 11Aa so as to move away from the first upper raceway surface 11Aa, and the minimum radius of the rotation locus (the distance from point O2 to points P4 and P5 on the second upper inclined surface 11Ad and the third upper inclined surface 11Ae that are closest to point O2) is greater than the groove bottom radius r of the first upper raceway surface 11Aa. Here, edges EG1 and EG2 of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae that intersect with the end surface 2Aa of the slider body 2A form part of a circle centered at point O2.

[0053] The lower raceway groove 11B can be formed by machining in the same manner as the upper raceway groove 11A.

[0054] According to this embodiment, the chamfered portion can be machined simply by bringing the cutting tool TL close to the second upper raceway surface 11Ab along the machining axis O2, thereby shortening the machining time and improving the yield of the slider body 2A. Furthermore, since the chamfered portion is machined by removing a portion of the groove in the second upper raceway surface 11Ab, wear on the cutting tool TL is reduced, the maintenance intervals are extended, and the cost of the slider body 2A can be reduced.

[0055] Furthermore, in this embodiment, in addition to crowning, chamfers are provided at the top and bottom ends of the raceway grooves of the slider body 2A, where the rolling elements 3 are likely to collide, to blunt the edges, reducing the contact pressure during edge collisions and suppressing early wear of the rolling elements 3. Furthermore, by leaving the groove bottom direction as is with the crowning, the load zone that supports the load remains unchanged, maintaining durability and operability. From the above, it is possible to propose a linear motion guiding device that can accommodate a long life while maintaining durability.

[0056] That is, according to this embodiment, by forming a crowning shape and a chamfered portion in combination on the raceway grooves 11, 11B of the slider body 2A, smooth movement of the rolling elements 3 can be ensured even when the rolling elements 3 eccentrically enter the rolling paths 13A, 13B. Furthermore, since it is possible to prevent the rolling elements 3 from colliding with the edges at the ends of the rolling paths 13A, 13B, it is possible to suppress an increase in collision pressure when the rolling elements 3 enter the rolling paths 13A, 13B.

[0057] Second Embodiment Fig. 8(a) is a view similar to Fig. 5(a) of a second embodiment. Fig. 8(b) is a view of the upper raceway groove 11A, taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg 6 near both widthwise ends of the upper raceway groove 11A. Fig. 8(c) is a view showing a cross section of the end of the upper raceway groove 11A taken along the horizontal reference plane HP. Fig. 8(d) is a view showing a cross section of the end of the upper raceway groove 11A taken along the vertical reference plane VP.

[0058] In this embodiment, the shapes of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae of the upper raceway groove 11A are different from those of the first embodiment, and the shape of the first upper inclined surface 11Ac is also different accordingly. The same is true for the lower raceway groove 11B. Since the other configurations are the same as those of the first embodiment, repeated explanations will be omitted.

[0059] The first upper inclined surface 11Ac has a crowning shape that moves away from the center line O1 (vertical reference plane VP) of the straight portion of the rolling path 13A (upward in FIG. 8C ) as it moves away from the first upper raceway surface 11Aa. The crowning shape is an arc shape with a radius of curvature R1 in a cross section of FIG. 8C that includes the horizontal reference plane HP.

[0060] 8D, the second upper inclined surface 11Ad starts at a position a distance L2 from the end surface 2Aa of the slider body 2A (leg portion 6) and terminates at the end surface 2Aa. When the longitudinal length of the first upper inclined surface 11Ac is L1, L1 > L2.

[0061] The second upper inclined surface 11Ad has a chamfered shape that moves away from the horizontal reference plane HP (upward in FIG. 8(d)) as it moves away from the first upper track surface 11Aa. The chamfered shape is preferably an arc shape with a radius of curvature R2 in a cross section of FIG. 8(d) that includes the vertical reference plane VP. However, in this embodiment, unlike the first embodiment, R2≠∞, and the chamfered shape is an inwardly convex shape.

[0062] In the cross section shown in FIG. 8(d), it is preferable that the intersection point P1 where the first upper inclined surface 11Ac and the second upper inclined surface 11Ad intersect is a discontinuous point.

[0063] The first upper raceway surface 11Aa and the second upper raceway surface 11Ab are formed in the same manner as in the first embodiment. Then, a cutting tool TL is used to perform chamfering, thereby forming the second upper inclined surface 11Ad and the third upper inclined surface 11Ae. The cutting tool TL has a rotation locus whose outer periphery is arc-shaped (e.g., a tapered shape such as a toroidal shape) as shown by the chain lines in Figures 8(a) and 8(d). The maximum diameter of the rotation locus is larger than the vertical width of the first upper raceway surface 11Aa.

[0064] In addition, in a cross section perpendicular to the straight portion center line O1 (a cross section parallel to FIG. 8A ), the surfaces of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, which are chamfered portions, are on a rotation locus centered at point O2, which is shifted along the horizontal reference plane HP relative to the groove bottom center (straight portion center line O1) of the first upper raceway surface 11Aa so as to move away from the first upper raceway surface 11Aa, and the minimum radius of the rotation locus (the distance from point O2 to points P4 and P5 on the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, which are closest to point O2) is greater than the groove bottom radius r of the first upper raceway surface 11Aa. Here, edges EG1 and EG2 of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae that intersect with the end face 2Aa of the slider body 2A form part of a circle centered at point O2.

[0065] Specifically, as shown in Figure 8(a), a machining axis O2 is set within the horizontal reference plane HP, which is moved parallel to the center line O1 of the straight portion of the rolling path 13A so as to move the axis O2 away from the upper raceway groove 11A. Then, while rotating the cutting tool TL around the machining axis O2, the cutting tool TL is brought close to the second upper raceway surface 11Ab along the machining axis O2 to perform grinding so as to remove a portion of the second upper raceway surface 11Ab. As a result, the second upper inclined surface 11Ad is ground, and at the same time, the third upper inclined surface 11Ae is ground.

[0066] The lower raceway groove 11B can be formed by machining in the same manner as the upper raceway groove 11A.

[0067] According to this embodiment, the cross-sectional shapes of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, etc. are made arc-shaped, which reduces the sharpness of the edge portion (intersection point P1) and makes the chamfered portion smooth and curved, thereby reducing contact surface pressure and further reducing clogging of the rolling element 3, thereby suppressing early wear and improving operability.

[0068] (Third embodiment) Figure 9(a) is a view similar to Figure 5(a) of a third embodiment. Figure 9(b) is a view of the upper raceway groove 11A, taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg 6 near both widthwise ends of the upper raceway groove 11A. Figure 9(c) is a view showing a cross section of the end of the upper raceway groove 11A taken along the horizontal reference plane HP. Figure 9(d) is a view showing an upper cross section of the end of the upper raceway groove 11A taken along the vertical reference plane VP.

[0069] In this embodiment, the second upper inclined surface 11Ad and the third upper inclined surface 11Ae of the upper raceway groove 11A are connected on the end face 2Aa side, and the shape of the first upper inclined surface 11Ac is accordingly different from that of the first embodiment. The same is true for the lower raceway groove 11B. Other configurations are the same as those of the first embodiment, and therefore, repeated explanations will be omitted.

[0070] Above the horizontal reference plane HP, the second upper raceway surface 11Ab has a first upper inclined surface 11Ac and a second upper inclined surface 11Ad. The first upper inclined surface 11Ac has a crowning shape that moves away from the center line O1 (vertical reference plane VP) of the straight portion of the rolling path 13A (upward in FIG. 9C ) as it moves away from the first upper raceway surface 11Aa, but terminates before reaching the end face 2Aa. The crowning shape is an arc shape with a radius of curvature R1 in a cross section of FIG. 9C that includes the horizontal reference plane HP.

[0071] 9D, the second upper inclined surface 11Ad starts at a position a distance L2 from the end surface 2Aa of the slider body 2A (leg portion 6) and terminates at the end surface 2Aa. When the longitudinal length of the first upper inclined surface 11Ac is L1, L1 > L2.

[0072] The second upper inclined surface 11Ad has a chamfered shape that moves away from the horizontal reference plane HP (upward in FIG. 9(d)) as it moves away from the first upper track surface 11Aa. The chamfered shape is preferably an arc shape with a radius of curvature R2 in a cross section of FIG. 9(d) that includes the vertical reference plane VP. In this embodiment, R2 may be set to ∞, or R2 may be set to < R1.

[0073] Below the horizontal reference plane HP, the inner surface of the upper raceway groove 11A is a part of a cylindrical surface. Therefore, using the cutting tool TL of the above-described embodiment, only the second upper inclined surface 11Ad can be formed by chamfering. The lower raceway groove 11B can also be formed in the same manner.

[0074] That is, in a cross section perpendicular to the straight portion center line O1 (a cross section parallel to FIG. 9A ), the surfaces of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, which are chamfered portions, are on a rotation locus centered at point O2, which is shifted along the horizontal reference plane HP relative to the groove bottom center (straight portion center line O1) of the first upper raceway surface 11Aa so as to move away from the first upper raceway surface 11Aa, and the minimum radius of the rotation locus (the distance from point O2 to points P4 and P5 on the second upper inclined surface 11Ad and the third upper inclined surface 11Ae that are closest to point O2) is greater than the groove bottom radius r of the first upper raceway surface 11Aa. Here, edges EG3 of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae that intersect with the end face 2Aa of the slider body 2A are connected and form part of a circle centered at point O2. The second upper inclined surface 11Ad and the third upper inclined surface 11Ae of this embodiment can be machined and formed by adjusting the amount of cut along the machining axis O2 using the above-mentioned cutting tool.

[0075] As shown in Figure 9 (b), the two chamfered portions, the second upper inclined surface 11Ad and the third upper inclined surface 11Ae, are integrated near the bottom of the groove, which allows the edge portion of the groove bottom to be removed while maintaining the crowning, thereby having the effect of suppressing premature wear while maintaining durability and operability.

[0076] (Fourth embodiment) Fig. 10(a) is a view similar to Fig. 5(a) but showing a fourth embodiment. Fig. 10(b) is a view of the upper raceway groove 11A, taken by cutting the leg portion 6 shown in Fig. 10(a) along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg portion 6 near both widthwise ends of the upper raceway groove 11A. Fig. 10(c) is a view showing an upper cross section of the end of the upper raceway groove 11A, taken along an inclined plane SP that includes the center line O1 of the straight portion of the rolling path 13A and is inclined relative to the horizontal reference plane HP. Fig. 10(d) is a view showing a cross section of the end of the upper raceway groove 11A taken along the vertical reference plane VP.

[0077] In this embodiment, the shape of the upper raceway groove 11A differs from that of the first embodiment above and below the horizontal reference plane HP. The same is true for the lower raceway groove 11B. Other configurations are the same as those of the first embodiment, so repeated explanations will be omitted.

[0078] The second upper raceway surface 11Ab has a first upper inclined surface 11Ac and a second upper inclined surface 11Ad. The first upper inclined surface 11Ac has a crowning shape that moves away from the center line O1 (vertical reference plane VP) of the straight portion of the rolling path 13A (upward in FIG. 10(c)) as it moves away from the first upper raceway surface 11Aa, but terminates before reaching the end face 2Aa. The crowning shape is an arc shape with a radius of curvature R1 in a cross section of FIG. 10(c) that includes the horizontal reference plane HP.

[0079] 10D, the second upper inclined surface 11Ad starts at a position a distance L2 from the end surface 2Aa of the slider body 2A (leg portion 6) and terminates at the end surface 2Aa. When the longitudinal length of the first upper inclined surface 11Ac is L1, L1 > L2.

[0080] The second upper inclined surface 11Ad has a chamfered shape that moves away from the horizontal reference plane HP and the vertical reference plane VP (upward in FIG. 10(d)) as it moves away from the first upper track surface 11Aa. The chamfered shape is preferably an arc shape with a radius of curvature R2 in the cross section of FIG. 10(d) that includes the inclined surface SP. In this embodiment, R2 may be ∞ or R2 may be less than R1.

[0081] In the cross section shown in FIG. 10(d), it is preferable that the intersection point P1 where the first upper inclined surface 11Ac and the second upper inclined surface 11Ad intersect is a discontinuous point.

[0082] That is, in a cross section perpendicular to the straight portion center line O1 (a cross section parallel to FIG. 10A ), the surface of the second upper inclined surface 11Ad, which is a chamfered portion, is located on a rotation locus centered at point O2, which is shifted along the horizontal reference plane HP relative to the groove bottom center (straight portion center line O1) of the first upper raceway surface 11Aa so as to move away from the first upper raceway surface 11Aa, and the minimum radius of the rotation locus (the distance from point O2 to point P4 on the second upper inclined surface 11Ad closest to point O2) is greater than the groove bottom radius r of the first upper raceway surface 11Aa. Here, the edge EG1 of the second upper inclined surface 11Ad intersecting with the end surface 2Aa of the slider body 2A is part of a circle centered at point O2. Note that instead of omitting the second upper inclined surface 11Ad, a third upper inclined surface 11Ae may be provided.

[0083] The cross-sectional shape of the upper raceway groove 11A etc. is not limited to a semicircular shape as in this embodiment, and even in cases where it is necessary to take into consideration the contact angle between the rolling elements 3 and the upper raceway groove 11A etc., or where the chamfered portion is limited to a portion where the rolling elements 3 are likely to collide, the same effects as in the above-described embodiment can be obtained.

[0084] Fifth Embodiment Fig. 11(a) is a view similar to Fig. 5(a) but showing a fifth embodiment. Fig. 11(b) is a view of the upper raceway groove 11A, taken along a vertical reference plane VP that is perpendicular to the horizontal reference plane HP and passes through the leg 6 near both widthwise ends of the upper raceway groove 11A. Fig. 11(c) is a view showing a cross section of the end of the upper raceway groove 11A taken along the horizontal reference plane HP. Fig. 11(d) is a view showing a cross section of the end of the upper raceway groove 11A taken along the vertical reference plane VP.

[0085] The shape of the upper raceway groove 11A in this embodiment is similar to that in the first embodiment, but the surface roughness of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae is coarser than that of the first upper inclined surface 11Ac. The surface roughness of the first upper inclined surface 11Ac is substantially equal to that of the first upper raceway surface 11Aa. The surface roughness can be evaluated by the arithmetic mean roughness Ra, etc. For example, the arithmetic mean roughness Ra of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae is preferably 50% or more coarser than the arithmetic mean roughness Ra of the first upper inclined surface 11Ac. The same is true for the lower raceway groove 11B. Other configurations are similar to those in the first embodiment, so repeated explanations will be omitted.

[0086] For example, the surface roughness of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae can be made rougher than that of the first upper inclined surface 11Ac by performing chamfering processing with a grinding tool with large abrasive grains, forming tool marks on the chamfered portion with a cutting tool, etc. By making the surface roughness of the second upper inclined surface 11Ad and the third upper inclined surface 11Ae rougher, adhesion of lubricant to the chamfered portion is promoted, and damage when the rolling element 3 collides with the chamfered portion can be expected to be suppressed.

[0087] The present invention is not limited to the above-described embodiments, and the present invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the description in the specification and well-known techniques, and these modifications and applications are included in the scope of protection sought.

[0088] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0089] This application is based on a Japanese patent application (Patent Application No. 2023-223377) filed on December 28, 2023, the contents of which are incorporated herein by reference.

[0090] REFERENCE SIGNS LIST 1 guide rail 2 slider 2A slider body 2B end cap 3 rolling element 4 cage 10A, 10B raceway groove 11A, 11A raceway groove 13A, 13B rolling path 14A, 14B return path 15 direction change path

Claims

1. A linear guide device comprising a guide rail, a slider arranged to move relative to the guide rail in the longitudinal direction, and a plurality of rolling elements arranged to roll freely along a rolling path formed between the guide rail and the slider, wherein the slider includes a slider body having a raceway groove facing the raceway groove of the guide rail to form the rolling path of the rolling elements and a return path for the rolling elements, and an end cap having a direction-changing path connecting the return path and the rolling path, the raceway groove of the slider body has a first raceway surface on the central portion side of the rolling path and a second raceway surface on the end portion side of the rolling path, the second raceway surface has a first inclined surface extending from the first raceway surface to the end surface of the slider body and a chamfer portion extending to the end surface of the slider body without contacting the first inclined surface, with a plane passing through the center in the width direction of the slider body and the longitudinal axis of the guide rail being defined as a vertical center plane CP, a plane perpendicular to the vertical center plane CP and passing through the center line of the straight portion of the rolling path being defined as a horizontal reference plane HP, and a plane parallel to the vertical center plane CP and intersecting the chamfer portion being defined as a vertical reference plane VP, the surface of the chamfer portion is on a rotational locus centered at a point O2 that is shifted along the horizontal reference plane HP so as to be separated from the first raceway surface with respect to the center line O1 of the straight portion of the rolling path in a cross section perpendicular to the center line of the straight portion, and the minimum radius of the rotational locus is greater than the groove bottom radius r of the first raceway surface.

2. The linear guide device according to claim 1, wherein the edge of the chamfer portion farthest from the point O2 is a part of a circle centered at the point O2.

3. The linear guide device according to claim 2, wherein the first inclined surface is spaced apart from the vertical reference plane VP as it approaches the end surface of the slider body, and the surface of the chamfer portion is spaced apart from the horizontal reference plane HP as it approaches the end surface of the slider body.

4. The linear guide device according to claim 3, wherein the cross-sectional shape of the first inclined surface obtained by cutting with the horizontal reference plane HP has an arc shape with a curvature radius R1, the cross-sectional shape of the surface of the chamfer portion obtained by cutting with the vertical reference plane VP has an arc shape with a curvature radius R2, and R2 < R1.

5. The cross-sectional shape of the first inclined surface obtained by cutting along the horizontal reference plane HP has an arc shape, and the intersection of the surface of the chamfered portion intersecting with the vertical reference plane VP is linear. The linear motion guide device according to claim 3, characterized in that.

6. A second inclined surface and a third inclined surface are formed on both sides of the first inclined surface with the horizontal reference plane interposed therebetween, and the second inclined surface and the third inclined surface are the chamfered portions. The linear motion guide device according to claim 1, characterized in that.

7. The second inclined surface and the third inclined surface are connected. The linear motion guide device according to claim 6, characterized in that.

8. A second inclined surface is formed on the side spaced apart from the first inclined surface with the horizontal reference plane interposed therebetween, and the second inclined surface is the chamfered portion. The linear motion guide device according to claim 1, characterized in that.

9. The surface roughness of the surface of the chamfered portion is different from the surface roughness of the first inclined surface. The linear motion guide device according to claim 1, characterized in that.

10. A method for manufacturing a linear motion guide device, comprising: a guide rail; a slider arranged to move relative to the guide rail in the longitudinal direction; and a plurality of rolling elements arranged to be rollable along a rolling passage formed between the guide rail and the slider. The slider includes a rail groove that is disposed opposite to the rail groove of the guide rail to form a rolling passage for the rolling element, and a slider body having a return passage for the rolling element, and an end cap having a direction-changing passage that connects the return passage and the rolling passage. The rail groove of the slider body has a first rail surface on the central portion side of the rolling passage and a second rail surface on the end portion side of the rolling passage. The second rail surface has a first inclined surface that extends from the first rail surface to the end surface of the slider body, and a chamfered portion that extends to the end surface of the slider body without contacting the first inclined surface. A grinding tool or a cutting tool having a tapered rotation locus is rotated around a machining axis O2 that is translated parallel to the center line O1 of the straight portion of the rolling passage so as to be separated from the first rail surface, and is brought close to the second rail surface along the machining axis O2, and a part of the first inclined surface is cut off to form the chamfered portion. A method for manufacturing a linear motion guide device, characterized in that.

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