Linear motion guide unit

Abstract

To provide a linear motion guide unit capable of realizing smooth sliding movement of a slider.SOLUTION: A linear motion guide unit comprises a rail, a slider, and a plurality of rollers. The slider includes: a casing which is provided with a first circulation path parallel to a raceway path, and which includes a first guide surface that guides each roller by contact with a first end surface positioned on one side of the roller, and a second raceway surface; an end cap; and a holding member that holds the rollers in the casing. Each roller circulates through an annular path formed by the raceway path, the first circulation path and a second circulation path. The holding member includes: a holding plate that has a shape extending in a longitudinal direction and that has a second guide surface for guiding the rollers; and an attachment mechanism for attaching the holding plate to the casing side. The second guide surface is provided with: a plurality of recesses disposed at intervals smaller than the diameter of a second end surface positioned on the other side of the roller in the longitudinal direction; and a plurality of contact parts disposed between adjacent recesses and contacting the second end surface.SELECTED DRAWING: Figure 4

Description

[Technical field]

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

[0002] A linear motion guide unit including a rail, a roller as a rolling element, a slider that moves relatively along the rail, and a retaining plate that retains the roller on the slider is known (see, for example, Patent Documents 1, 2 and 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-164424 A [Patent Document 2] JP 2023-102377 A [Patent Document 3] JP 2009-236152 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a linear motion guide unit, if the sliding resistance of the slider is large, the smooth sliding of the slider is hindered, and it is therefore necessary to realize the smooth sliding of the slider.

[0005] Therefore, it is an object of the present invention to provide a linear motion guide unit that can realize smooth sliding of a slider. [Means for solving the problem]

[0006] A linear motion guide unit according to the present disclosure includes a rail having a first raceway surface extending in the longitudinal direction, a slider attached to the rail so as to be movable relative to the rail and having a second raceway surface facing the first raceway surface, and rollers as a plurality of rolling elements rolling on a raceway path formed by the first raceway surface and the second raceway surface. The slider includes a casing having a first circulation path parallel to the raceway path and including a first guide surface and a second raceway surface that contact a first end face located on one side of the roller to guide the roller, an end cap arranged on one side of the casing in the longitudinal direction and having a second circulation path connecting the raceway path and the first circulation path, and a holding member that holds the roller in the casing. Each roller circulates on a ring path formed by the raceway path, the first circulation path, and the second circulation path. The holding member includes a holding plate having a shape extending in the longitudinal direction and a second guide surface that guides the roller, and an attachment mechanism that attaches the holding plate to the casing side. The second guide surface is provided with a plurality of recesses arranged at intervals smaller than the diameter of the second end face located on the other side of the roller in the longitudinal direction, and a plurality of contact portions arranged between adjacent recesses and in contact with the second end face. Effect of the Invention

[0007] According to the linear motion guide unit described above, smooth sliding of the slider can be achieved. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic perspective view showing a linear motion guide unit in accordance with the first embodiment of the present disclosure. [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along the line indicated by the arrows II-II in FIG. [Diagram 3] FIG. 3 is a schematic perspective view of the retaining plate. [Figure 4] FIG. 4 is an enlarged view of a region indicated by IV in FIG. [Diagram 5] FIG. 5 is a schematic side view of the retaining plate. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a portion of the slider when the retaining band is attached. [Figure 7] FIG. 7 is a schematic cross-sectional view showing, in an enlarged scale, a portion of the roller and slider with the retaining plate attached. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Overview of the embodiment] The linear guide unit of the present disclosure includes a rail having a first raceway surface extending in the longitudinal direction, a slider attached to the rail so as to be movable relative to the rail and having a second raceway surface facing the first raceway surface, and rollers as a plurality of rolling elements rolling on a raceway path composed of the first raceway surface and the second raceway surface. The slider includes a casing having a first circulation path parallel to the raceway path and including a first guide surface and a second raceway surface that contact a first end face located on one side of the roller to guide the roller, an end cap arranged on one side of the casing in the longitudinal direction and having a second circulation path connecting the raceway path and the first circulation path, and a holding member that holds the roller in the casing. Each roller circulates on a ring path composed of the raceway path, the first circulation path, and the second circulation path. The holding member includes a holding plate having a shape extending in the longitudinal direction and a second guide surface that guides the roller, and an attachment mechanism that attaches the holding plate to the casing side. The second guide surface is provided with a plurality of recesses arranged at intervals smaller than the diameter of the second end face located on the other side of the roller in the longitudinal direction, and a plurality of contact portions arranged between adjacent recesses and in contact with the second end face.

[0010] According to the linear guide unit of the present disclosure, the second guide surface, which is included in the holding plate and guides the roller, includes a plurality of recesses and a plurality of contact portions alternately arranged in the longitudinal direction. The plurality of contact portions included in the second guide surface come into contact with the second end surface of the roller, and the roller can be guided in the load region. In this case, the recesses included in the second guide surface do not come into contact with the second end surface of the roller, and therefore the contact area of ​​the second guide surface with the second end surface of the roller can be reduced. This can reduce the frictional resistance between the second end surface of the roller and the second guide surface. In this case, the plurality of contact portions are arranged between the adjacent recesses at an interval smaller than the diameter of the second end surface of the roller, and therefore the second end surface of the roller and the contact portions can be maintained in constant contact with each other, and the roller can be reliably guided. Therefore, the sliding resistance can be reduced, and smooth sliding of the slider can be achieved.

[0011] In the linear guide unit, the contact portion may contact the second end face in a region including the central axis of rotation of the roller when viewed in the longitudinal direction. The slider may have a space between the second end face and the retaining plate in a region on the outer circumferential surface side of the contact portion. This reduces the frictional resistance between the second guide surface and the second end face when viewed in the longitudinal direction, while reducing the risk of pressing the second end face of the roller at an angle in the central axis direction of the roller, making it possible to guide the roller in a balanced manner. This makes it possible to further stabilize the posture of the roller.

[0012] In the linear guide unit, the first contact width of the contact portion may be 20% to 30% of the diameter of the second end face when viewed in the longitudinal direction. This makes it possible to optimize the contact area between the second end face and the contact portion when viewed in the longitudinal direction, thereby reducing sliding resistance and stress concentration.

[0013] In the linear guide unit, the second contact width of the contact portion in the longitudinal direction may be 55% or more and 75% or less of the diameter of the second end face. This makes it possible to optimize the contact area between the second end face and the contact portion in the longitudinal direction, thereby reducing sliding resistance and stress concentration.

[0014] In the linear guide unit, the mounting mechanism may include a retaining band capable of elastic deformation. The retaining plate may be provided with a slit penetrating the end side in the longitudinal direction. The slit may be provided at a position where the retaining band contacts and presses the retaining plate. In this way, the retaining plate can be elastically deformed appropriately in the region of the retaining plate where the slit is provided, and the roller can be moved to the load region while more appropriately pressing the second end surface of the roller to correct its posture. Therefore, smoother sliding of the slider can be realized.

[0015] In the linear motion guide unit, a pair of slits may be provided at both longitudinal end sides, thereby making it possible to reduce sliding resistance during linear reciprocating motion of the slider.

[0016] In the linear motion guide unit, the length of the slit in the longitudinal direction may be such that the amount of elastic deformation of the retaining plate is 20% to 40% of the maximum gap in the direction of the central axis of rotation of the roller. This makes it possible to suppress tilt of the roller after it enters the load area while allowing the retaining plate to be appropriately elastically deformed.

[0017] The linear guide unit of the present disclosure includes a rail having a first raceway surface extending in the longitudinal direction, a slider attached to the rail so as to be movable relative to the rail and having a second raceway surface facing the first raceway surface, and rollers as a plurality of rolling elements rolling on a raceway path composed of the first raceway surface and the second raceway surface. The slider includes a casing having a first circulation path parallel to the raceway path and including a first guide surface and a second raceway surface that contact a first end face located on one side of the roller to guide the roller, an end cap arranged on one side of the casing in the longitudinal direction and having a second circulation path connecting the raceway path and the first circulation path, and a holding member that holds the roller in the casing. Each roller circulates on a ring path composed of the raceway path, the first circulation path, and the second circulation path. The holding member includes a holding plate having a shape extending in the longitudinal direction and a second guide surface that guides the roller, and an attachment mechanism that attaches the holding plate to the casing side. The second guide surface is provided with a plurality of recesses arranged at intervals smaller than the diameter of the second end face located on the other side of the roller in the longitudinal direction, and a plurality of contact portions arranged between adjacent recesses and in contact with the second end face. When viewed in the longitudinal direction, the contact portions contact the second end face in a region including the central axis of rotation of the roller. A space is provided in the slider between the second end face and the retaining plate in a region on the outer circumferential surface side of the contact portions.

[0018] According to such a linear motion guide unit, the position of the roller can be made more stable, while the slider can slide smoothly.

[0019] [Specific Example of the Embodiment] Next, an example of a specific embodiment of the linear guide unit of the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

[0020] (Embodiment 1) First, a first embodiment of the present disclosure will be described. FIG. 1 is a schematic perspective view showing a linear guide unit in the first embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view taken along the line indicated by the arrows II-II in FIG. 1. In FIG. 1 and the following figures, the X direction indicates the short side direction, which is the width direction of the linear guide unit, the Y direction indicates the longitudinal direction of the linear guide unit, and the Z direction indicates the thickness direction (height direction) of the linear guide unit. The X direction, the Y direction, and the Z direction are each perpendicular to each other. FIG. 2 is a cross-sectional view taken along a plane perpendicular to the Y direction, i.e., the XZ plane.

[0021] 1 and 2, the linear guide unit 10a according to the first embodiment of the present disclosure includes a rail 11a, which is a track rail, a slider 21a, and a plurality of rollers 20a, 20b, 20c, and 20d as rolling elements. The rail 11a is configured to extend straight in the Y direction, which is the longitudinal direction. The linear guide unit 10a according to the first embodiment includes a plurality of rollers 20a, 20b, 20c, and 20d as rolling elements, and thus can have a large rated load while being compact in size, as compared with a case in which the rolling elements are balls. In this embodiment, the linear guide unit 10a is a so-called four-row linear guide unit. The rollers 20a and 20b each include rolling surfaces 28a and 28b, first end faces 51a and 51b located on one side of the rotation axis direction of the rollers 20a and 20b, and second end faces 52a and 52b located on the other side of the rotation axis direction. Similarly, rollers 20c, 20d each include a rolling surface, a first end face located on one side in the rotational axis direction of rollers 20c, 20d, and a second end face located on the other side in the rotational axis direction.

[0022] First, the configuration of the rail 11a will be described. The rail 11a includes a rail upper end surface 12a and a rail lower 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 rail front end surface 14a and a rail rear end surface 14b spaced apart in the Y direction. That is, the rail 11a includes the first rail side surface 13a and the second rail side surface 13b that extend parallel to each other along the longitudinal direction. The rail 11a has a pair of first track grooves 15a, 15b that extend parallel to each other in the longitudinal direction. The first track groove 15a is provided on the first rail side surface 13a. The first track groove 15b is provided on the second rail side surface 13b.

[0023] The first track groove 15a is composed of first track surfaces 16a, 16b and a side wall surface 17a. The first track surface 16a is inclined with respect to the XY plane and is provided on the rail upper end surface 12a side. The first track surface 16b is inclined with respect to the XY plane and is provided on the rail lower end surface 12b side. The side wall surface 17a is provided so as to be continuous with each of the first track surfaces 16a and 16b. The first track groove 15b is also composed of first track surfaces 16c, 16d and a side wall surface 17b, similar to the first track groove 15a. The first track surface 16c is inclined with respect to the XY plane and is provided on the rail upper end surface 12a side. The first track surface 16d is inclined with respect to the XY plane and is provided on the rail lower end surface 12b side. The side wall surface 17b is provided so as to be continuous with each of the first track surfaces 16c and 16d. That is, the rail 11a includes first raceway surfaces 16a, 16b, 16c, and 16d extending in the longitudinal direction. A linear motion guide unit 10a including such a rail 11a is suitable for use in machine tools, assembly devices, conveying machines, and the like.

[0024] The rail 11a is provided with a plurality of through holes 18 penetrating in the Z direction from the rail upper end surface 12a to the rail lower end surface 12b. The plurality of through holes 18 are provided at intervals in the Y direction. The through holes 18 are each effectively used when attaching the rail 11a to a predetermined location, for example, when using the linear motion guide unit 10a.

[0025] Next, the configuration of the slider 21a will be described. The slider 21a is attached to the rail 11a so as to be relatively movable. In this embodiment, the slider 21a is slidably mounted on the rail 11a. The slider 21a is provided with a fitting portion 24a recessed in the Z direction, and the slider 21a is attached so as to be fitted into the fitting portion 24a. In other words, the slider 21a is attached so as to straddle the rail 11a, and is configured to be movable in the Y direction.

[0026] The slider 21a includes a casing 22a, a pair of end caps 23a, 23b, specifically, a first end cap 23a, a second end cap 23b, and holding members 41a, 41b that hold the rollers 20a, 20b, 20c, 20d on the casing 22a. The configuration of the holding members 41a, 41b will be described in detail later. The first end cap 23a is disposed on one side of the casing 22a in the longitudinal direction, specifically, on the rail front end surface 14a side of the casing 22a in the longitudinal direction. The second end cap 23b is disposed on the other side of the casing 22a in the longitudinal direction, specifically, on the rail rear end surface 14b side of the casing 22a in the longitudinal direction. That is, the slider 21a includes a pair of end caps 23a, 23b disposed on both sides of the casing 22a in the longitudinal direction. The first end cap 23a is provided with a through hole penetrating in the Y direction. Both the first end cap 23a and the second end cap 23b are so-called plate-shaped with the thickness direction being the longitudinal direction. The first end cap 23a is connected to the casing 22a by a plurality of bolts using the through holes. The second end cap 23b is connected to the casing 22a by a plurality of bolts using the through holes. The end cap 23a is also provided with a supply hole (not shown) for supplying lubricating oil. The same is true for the end cap 23b.

[0027] The slider 21a includes an end seal 27a disposed on one side of the first end cap 23a in the longitudinal direction, and a lubricating member (not shown) that applies lubricating oil. The end seal 27a and the lubricating member are attached to the first end cap 23a by bolts. The second end cap 23b, like the first end cap 23a, is connected to the casing 22a by a plurality of bolts together with the end seal 27b and the lubricating member. The casing 22a is provided with a plurality of through holes 29 that penetrate in the Z direction. In this embodiment, six through holes 29 are provided. The six through holes 29 are provided at intervals in the X direction and the Y direction, and are used, for example, when connecting the slider 21a to another member.

[0028] The casing 22a includes second raceway surfaces 32a, 32b, 32c, and 32d that face the first raceway surfaces 16a, 16b, 16c, and 16d, respectively. The raceway 31a on which the roller 20a rolls is composed of the first raceway surface 16a and the second raceway surface 32a. The raceway 31b on which the roller 20b rolls is composed of the first raceway surface 16b and the second raceway surface 32b. The raceway 31c on which the roller 20c rolls is composed of the first raceway surface 16c and the second raceway surface 32d. The raceway 31d on which the roller 20d rolls is composed of the first raceway surface 16d and the second raceway surface 32d.

[0029] The casing 22a is provided with first circulation paths 33a, 33b, 33c, and 33d that are parallel to the raceways 31a, 31b, 31c, and 31d, respectively. The first circulation paths 33a, 33b, 33c, and 33d are also called return paths. A hollow cylindrical sleeve 34a formed by combining the first divided member 35a and the second divided member 36a is disposed in the first circulation path 33a. A plurality of rollers 20a move in the sleeve 34a. Similarly, a hollow cylindrical sleeve 34b formed by combining the first divided member 35b and the second divided member 36b is disposed in the first circulation path 33b. A hollow cylindrical sleeve 34c formed by combining the first divided member 35c and the second divided member 36c is disposed in the first circulation path 33c. A hollow cylindrical sleeve 34d formed by combining the first divided member 35d and the second divided member 36d is disposed in the first circulation path 33d.

[0030] The casing 22a includes first guide surfaces 39a, 39b, 39c, and 39d that contact first end surfaces 51a and 51b located on one side of the rollers 20a, 20b, 20c, and 20d to guide the rollers 20a, 20b, 20c, and 20d.

[0031] The first end cap 23a is provided with a second circulation path (not shown). The second circulation path is also called a direction change path. The second circulation path is recessed in an arc shape in the thickness direction (Y direction) of the first end cap 23a so as to allow the movement of the rollers 20a. The second circulation path connects the raceway path 31a and the first circulation path 33a. The first end cap 23a includes a second circulation path connecting the raceway path 31b and the first circulation path 33b, a second circulation path connecting the raceway path 31c and the first circulation path 33c, and a second circulation path connecting the raceway path 31d and the first circulation path 33d. Similarly to the first end cap 23a, the second end cap 23b includes a second circulation path connecting the raceway 31a and the first circulation path 33a, a second circulation path connecting the raceway 31b and the first circulation path 33b, a second circulation path connecting the raceway 31c and the first circulation path 33c, and a second circulation path connecting the raceway 31d and the first circulation path 33d. The rollers 20a circulate in a circular path formed by the raceway 31a, the second circulation path of the second end cap 23b, the first circulation path 33a, and the second circulation path of the first end cap 23a. The rollers 20b circulate in a circular path formed by the raceway 31b, the second circulation path of the second end cap 23b, the first circulation path 33b, and the second circulation path of the first end cap 23a. The rollers 20c circulate around an annular path formed by the raceway 31c, the second circulation path of the second end cap 23b, the first circulation path 33c, and the second circulation path of the first end cap 23a. The rollers 20d circulate around an annular path formed by the raceway 31d, the second circulation path of the second end cap 23b, the first circulation path 33d, and the second circulation path of the first end cap 23a.

[0032] Next, the configuration of the holding members 41a and 41b that hold the rollers 20a, 20b, 20c, and 20d in the casing 22a will be described. The holding member 41a includes a holding plate 42a and a holding band 43a as an attachment mechanism. The holding member 41b includes a holding plate 42b and a holding band 43b, similar to the holding member 41a. The configuration of the holding member 41b is similar to that of the holding member 41a, so a description thereof will be omitted.

[0033] FIG. 3 is a schematic perspective view of the holding plate 42a. FIG. 4 is an enlarged view of an area indicated by IV in FIG. 3. FIG. 5 is a schematic side view of the holding plate 42a. FIG. 5 is a view seen in the opposite direction to the direction indicated by the arrow X. FIG. 6 is a schematic cross-sectional view showing a part of the slider 21a when the holding band 43a is attached. FIG. 6 is a cross-sectional view taken along a plane parallel to the XY plane. In FIG. 6, the state before the holding band 43a is attached is shown by a two-dot chain line. FIG. 7 is a schematic cross-sectional view showing an enlarged part of the roller 20a and the slider 21a when the holding plate 42a is attached.

[0034] 3 to 7, the holding plate 42a and the holding band 43a included in the holding member 41a each have a shape extending in the longitudinal direction. The holding plate 42a is provided with a groove 47a that is recessed to accommodate the holding band 43a. Specifically, the rod-shaped portion 44a of the holding band 43a is fitted into the groove 47a. The groove 47a has a shape extending along the longitudinal direction. The holding plate 42b is also provided with a groove 47b, similar to the holding plate 42a.

[0035] Here, the configuration of the retaining band 43a will be briefly described. The retaining band 43a is formed by bending, for example, a long and thin metal member. The retaining band 43a is capable of elastic deformation to a certain extent. The retaining band 43a includes a rod-shaped portion 44a extending in the longitudinal direction, and a pair of claw portions 45a, 45b disposed at both longitudinal ends of the rod-shaped portion 44a. The rod-shaped portion 44a is shaped such that both longitudinal ends are warped in the direction of the arrow X when the longitudinal center of the rod-shaped portion 44a contacts the retaining plate 42a before the retaining band 43a is attached. The pair of claw portions 45a, 45b are each bent in the X direction, and the tip portions 48a, 48b of the pair of claw portions 45a, 45b are further bent in the Y direction. When attaching the retaining band 43a, the rod-shaped portion 44a is fitted into the groove portion 47a and is pressed against the retaining plate 42a at the center in the longitudinal direction, and the pair of claw portions 45a, 45b and the pair of tip portions 48a, 48b are hooked onto the pair of end caps 23a, 23b so as to hold the retaining plate 42a. Then, both ends of the rod-shaped portion 44a are slightly elastically deformed, and the retaining plate 42a is attached to the casing 22a by this pressing force. The areas indicated by 49a, 49b, 49c, and 49d in FIG. 6 are areas where the load is concentrated.

[0036] Next, the configuration of the holding plate 42a will be described. The holding plate 42a includes second guide surfaces 46a, 46b that contact the second end surfaces 52a, 52b located on the other side of the rollers 20a, 20b, respectively, to guide the rollers 20a, 20b. With particular reference to FIG. 4, the second guide surface 46a is provided with a plurality of recesses 53a and a plurality of contact portions 54a. The same is true for the second guide surface 46b. The plurality of recesses 53a are arranged at intervals D2 smaller than the diameter D1 of the second end surface 52a of the roller 20a in the longitudinal direction. The plurality of recesses 53a are each configured to extend in a groove shape in a direction perpendicular to the rotational central axis direction of the roller 20a on the second guide surface 46a. The plurality of contact portions 54a contact the second end surface 52a of the roller 20a. The plurality of contact portions 54a are arranged between adjacent recesses 53a. That is, on the second guide surface 46a, the multiple recesses 53a and the multiple contact portions 54a are arranged alternately in the longitudinal direction.

[0037] With particular reference to FIG. 7, the contact portion 54a contacts the second end face 52a in a region including the rotation axis 25a of the roller 20a when viewed in the longitudinal direction. In the slider 21a, spaces 55a and 55b are provided between the second end face 52a and the retaining plate 42a in a region on the outer circumferential surface side of the contact portion 54a. In FIG. 7, the rotation axis 25a is indicated by a dashed line. Also, when viewed in the longitudinal direction, the first contact width L1 of the contact portion 54a is 20% or more and 30% or less of the diameter D1 of the second end face 52a. In this embodiment, it is 25%. Also, with reference to FIG. 4, the second contact width L2 of the contact portion 54a in the longitudinal direction is 55% or more and 75% or less of the diameter D1 of the second end face 52a. In this embodiment, it is 66%. That is, the second end surface 52a of the roller 20a comes into contact with the second guide surface 46a while moving in the longitudinal direction in a region where the contact portion 54a, which is not provided with the recess 53a and the spaces 55a and 55b, is located.

[0038] The retaining plate 42a is provided with slits 56a and 56b. The slits 56a and 56b are provided as a pair at both ends in the longitudinal direction. The slits 56a and 56b penetrate at the ends in the longitudinal direction. In this embodiment, the slits 56a and 56b are provided in the groove portion 47a. The slits 56a and 56b are provided at positions where the retaining band 43a contacts and presses the retaining plate 42a. Specifically, the slits 56a and 56b are provided at positions including the regions 49a and 49b in the longitudinal direction.

[0039] In this embodiment, the length of the slit 56a in the longitudinal direction is such that the amount of elastic deformation of the holding plate 42a is 20% to 40% of the maximum gap in the direction of the rotation axis 25a of the roller 20a. This will be explained as follows. With particular reference to Figs. 6 and 7, the length of the slit 56a in the longitudinal direction is L3, the length in the direction of the rotation axis 25a of the roller 20a is L4, the distance between the holding plate 42a and the casing 22a in the direction of the rotation axis 25a of the roller 20a is D3, and the gap in the direction of the rotation axis 25a of the roller 20a in the raceway 31a is C. In this case, the gap C corresponds to the value obtained by subtracting the length L4 from the distance D3. Here, the maximum gap refers to the length dimension that is maximum in the design value (the allowable error in the direction of the rotation axis 25a of the roller 20a). The length L3 of the slit 56a is a length at which the amount of elastic deformation of the holding plate 42a is 20% to 40% of the maximum value of the gap C. The same is true for the slit 56b. As specific dimensions, for example, the length L3 is 10 mm, the gap C is 93 μm, and the amount of elastic deformation of the holding plate 42a is 30 μm.

[0040] According to the linear motion guide unit 10a having such a configuration, the second guide surface 46a, which is included in the retaining plate 42a and guides the roller 20a, includes a plurality of recesses 53a and a plurality of contact portions 54a arranged alternately in the longitudinal direction. The plurality of contact portions 54a included in the second guide surface 46a contact the second end surface 52a of the roller 20a, and the roller 20a can be guided in the load region. In this case, the recesses 53a included in the second guide surface 46a do not contact the second end surface 52a of the roller 20a, so that the contact area between the second guide surface 46a and the second end surface 52a of the roller 20a can be reduced. This can reduce the frictional resistance between the second end surface 52a of the roller 20a and the second guide surface 46a. In this case, the contact portions 54a are disposed between the adjacent recesses 53a at intervals smaller than the diameter of the second end surface 52a of the roller 20a, so that the second end surface 52a of the roller 20a and the contact portions 54a can be constantly maintained in contact with each other, and the roller 20a can be reliably guided. This reduces the sliding resistance, and allows the slider 21a to slide smoothly.

[0041] In this embodiment, the contact portion 54a contacts the second end face 52a in a region including the rotation central axis 25a of the roller 20a when viewed in the longitudinal direction. The slider 21a has spaces 55a, 55b between the second end face 52a and the holding plate 42a in a region on the outer circumferential surface side of the contact portion 54a. Therefore, while reducing the frictional resistance between the second guide surface 46a and the second end face 52a when viewed in the longitudinal direction, the risk of pressing the second end face 52a of the roller 20a at an angle in the rotation central axis direction of the roller 20a is reduced, and the roller 20a can be guided in a well-balanced manner. Therefore, the posture of the roller 20a can be more stabilized.

[0042] In this embodiment, the first contact width L1 of the contact portion 54a is 20% to 30% of the diameter D1 of the second end face 52a when viewed in the longitudinal direction. Therefore, the contact area between the second end face 52a and the contact portion 54a when viewed in the longitudinal direction can be made appropriate, thereby reducing the sliding resistance and the stress concentration.

[0043] In this embodiment, the second contact width L2 of the contact portion 54a in the longitudinal direction is 55% to 75% of the diameter D1 of the second end face 52a. Therefore, the contact area between the second end face 52a and the contact portion 54a in the longitudinal direction can be made appropriate, thereby reducing the sliding resistance and the stress concentration.

[0044] In this embodiment, the mounting mechanism includes a retaining band 43a that can be elastically deformed. The retaining plate 42a is provided with slits 56a, 56b that penetrate the end side in the longitudinal direction. The positions where the slits 56a, 56b are provided are the regions 49a, 49b where the retaining band 43a contacts and presses the retaining plate 42a. Therefore, the retaining plate 42a can be appropriately elastically deformed in the regions 49a, 49b of the retaining plate 42a where the slits 56a, 56b are provided, and the roller 20a can be moved to the load region while more appropriately pressing the second end surface 52a of the roller 20a and correcting its posture. Therefore, smoother sliding of the slider 21a can be realized.

[0045] In this embodiment, a pair of slits 56a, 56b are provided at both ends in the longitudinal direction, thereby reducing the sliding resistance during linear reciprocating motion of the slider 21a.

[0046] In this embodiment, the longitudinal length of the slits 56a, 56b is such that the amount of elastic deformation of the retaining plate 42a is 20% to 40% of the maximum gap in the direction of the rotation axis 25a of the roller 20a. Therefore, the inclination of the roller 20a after entering the load area can be suppressed while the retaining plate 42a is appropriately elastically deformed.

[0047] (Other embodiments) In the above embodiment, the holding plate is provided with slits, but the present invention is not limited to this, and the holding plate may be configured without slits. Also, instead of providing a pair of slits, only one of the slits may be provided.

[0048] In addition, in the above embodiment, the mounting mechanism employs a configuration in which the retaining plate is held on the casing side using a retaining band, but this is not limited to this, and for example, the retaining plate may be fixed to the casing side with a bolt or the like, or the retaining plate may be glued to the casing side.

[0049] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0050] 10a linear motion guide unit, 11a rail, 12a rail upper end surface, 12b rail lower end surface, 13a first rail side surface, 13b second rail side surface, 14a rail front end surface, 14b rail rear end surface, 15a, 15b first raceway groove, 16a, 16b, 16c, 16d first raceway surface, 17a, 17b side wall surface, 18 through hole, 20a, 20b, 20c, 20d roller, 21a slider, 22a casing, 23a end cap (first end cap), 23b end cap (second end cap), 24a fitting portion, 25a rotation center shaft, 27a, 27b end seal, 28a, 28b rolling surface, 31a, 31b, 31c, 31d Raceway, 32a, 32b, 32c, 32d Second raceway, 33a, 33b, 33c, 33d First circulation path, 34a, 34b, 34c, 34d Sleeve, 35a, 35b, 35c, 35d First divided member, 36a, 36b, 36c, 36d Second divided member, 37a 2nd circulation path, 39a, 39b, 39c, 39d 1st guide surface, 41a, 41b holding member, 42a, 42b holding plate, 43a, 43b holding band, 44a bar, 45a, 45b claw portion, 46a, 46b 2nd guide surface, 47a, 47b groove, 48a, 48b Tip, 51a, 51b First end surface, 52a, 52b Second end surface, 53a Recess, 54a contact portion, 55a, 55b spaces, 56a, 56b slits.

Claims

1. a rail having a first raceway surface extending in a longitudinal direction; a slider attached to the rail so as to be relatively movable, the slider having a second track surface opposed to the first track surface; a plurality of rollers as rolling elements that roll on a raceway defined by the first raceway surface and the second raceway surface; The slider includes: a casing including a first circulating path parallel to the raceway, the casing including a first guide surface contacting a first end surface located on one side of the roller to guide the roller and the second raceway surface; an end cap disposed on one side of the casing in the longitudinal direction, the end cap including a second circulation path connecting the raceway and the first circulation path; a holding member for holding the roller in the casing, Each of the rollers circulates in a circular path formed by the raceway, the first circulation path, and the second circulation path, The holding member is a retaining plate having a shape extending in the longitudinal direction and having a second guide surface that guides the roller; an attachment mechanism for attaching the holding plate to the casing side; The second guide surface has: a plurality of recesses arranged at intervals smaller than a diameter of a second end face located on the other side of the roller in the longitudinal direction; a plurality of contact portions disposed between adjacent ones of the recesses and in contact with the second end surface are provided.

2. When viewed in the longitudinal direction, the contact portion contacts the second end surface in a region including a rotation central axis of the roller, 2. The linear motion guide unit according to claim 1, wherein a space is provided between said second end face and said retaining plate in an area on an outer circumferential surface side of said contact portion of said slider.

3. 3. The linear motion guide unit according to claim 1, wherein the first contact width of the contact portion is equal to or greater than 20% and equal to or less than 30% of a diameter of the second end face when viewed in the longitudinal direction.

4. 3. The linear motion guide unit according to claim 1, wherein the second contact width of the contact portion in the longitudinal direction is equal to or greater than 55% and equal to or less than 75% of a diameter of the second end face.

5. The attachment mechanism includes a resiliently deformable retaining band; The holding plate is provided with a slit penetrating the holding plate at an end side in the longitudinal direction, 3. The linear motion guide unit according to claim 1, wherein the slit is provided at a position where the retaining band comes into contact with and presses against the retaining plate.

6. 6. The linear motion guide unit according to claim 5, wherein the slits are provided in pairs at both ends in the longitudinal direction.

7. 6. The linear motion guide unit according to claim 5, wherein the length of said slit in the longitudinal direction is such that an amount of elastic deformation of said holding plate is 20% to 40% of a maximum gap in the direction of the central axis of rotation of said roller.

8. a rail having a first raceway surface extending in a longitudinal direction; a slider attached to the rail so as to be relatively movable, the slider having a second track surface opposed to the first track surface; a plurality of rollers as rolling elements that roll on a raceway defined by the first raceway surface and the second raceway surface; The slider includes: a casing including a first circulating path parallel to the raceway, the casing including a first guide surface contacting a first end surface located on one side of the roller to guide the roller and the second raceway surface; an end cap disposed on one side of the casing in the longitudinal direction, the end cap including a second circulation path connecting the raceway and the first circulation path; a holding member for holding the roller in the casing, Each of the rollers circulates in a circular path formed by the raceway, the first circulation path, and the second circulation path, The holding member is a retaining plate having a shape extending in the longitudinal direction and having a second guide surface that guides the roller; an attachment mechanism for attaching the holding plate to the casing side; The second guide surface has: a plurality of recesses arranged at intervals smaller than a diameter of a second end face located on the other side of the roller in the longitudinal direction; a plurality of contact portions disposed between adjacent recesses and in contact with the second end surface; When viewed in the longitudinal direction, the contact portion contacts the second end surface in a region including a rotation central axis of the roller, A space is provided between the second end face and the retaining plate in an area on the outer circumferential surface side of the contact portion of the slider.

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