Linear motion guide unit
The linear motion guide unit addresses roller skew and sliding resistance by using a retaining plate with deformable tongue-shaped portions to maintain roller posture, ensuring smooth operation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NIPPON THOMPSON
- Filing Date
- 2022-08-19
- Publication Date
- 2026-06-29
Smart Images
Figure 0007881411000001 
Figure 0007881411000002 
Figure 0007881411000003
Abstract
Description
Technical Field
[0001] The present disclosure relates to a linear guide unit.
Background Art
[0002] A linear guide unit including rollers as rolling elements is known (see, for example, Patent Document 1). The linear guide unit disclosed in Patent Document 1 includes a track rail, a slider that relatively moves along the track rail, and a holding plate that holds the rollers on the slider.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the linear guide unit disclosed in Patent Document 1, the slider is composed of a casing including a return path through which the rollers move, and a pair of end caps each including a direction-changing path for changing the direction of the rollers. The rollers circulate within a circulation path composed of the return path, the direction-changing path, and the track path.
[0005] Here, in the linear guide unit, if the roller enters the track path while tilted, the roller rolling on the track surface may not roll properly. As a result, there is a risk of an increase in the sliding resistance of the slider and heat generation. It is required to appropriately guide and correct the posture of the roller when the roller enters the track path to ensure smooth sliding of the slider.
[0006] Therefore, one of the objectives is to provide a linear guide unit that can ensure smooth sliding of the slider.
Means for Solving the Problems
[0007] A linear motion guide unit according to this disclosure comprises a rail having a first raceway surface extending in the longitudinal direction, a slider mounted to the rail so as to be movably relative to the rail and having a second raceway surface opposite to the first raceway surface, and a plurality of rollers as rolling elements that roll along a track formed by the first raceway surface and the second raceway surface. The slider includes a casing having a first circulation path parallel to the track and a first guide surface and a second raceway surface that contact a first end surface located on one side of the roller to guide the roller, an end cap disposed on one side in the longitudinal direction of the casing and having a second circulation path connecting the track and the first circulation path, and a retaining member for holding the roller in the casing. Each roller circulates along an annular path formed by the track, the first circulation path and the second circulation path. The retaining member includes a retaining plate having a longitudinal shape and a second guide surface that contacts a second end surface located on the other side of the roller to guide the roller, and a mounting mechanism for attaching the retaining plate to the casing side. The retaining plate is provided with a first tongue-shaped portion which includes a part of the second guide surface, with the end of the retaining plate in the longitudinal direction being the first fixed end and the center of the retaining plate in the longitudinal direction being the first free end, and a second tongue-shaped portion which includes a part of the second guide surface, with the center of the retaining plate in the longitudinal direction being the second fixed end and the end of the retaining plate in the longitudinal direction being the second free end. The first tongue-shaped portion includes a first raised portion provided on the second guide surface so as to protrude toward the first guide surface. The second tongue-shaped portion includes a second raised portion provided on the second guide surface so as to protrude toward the first guide surface. [Effects of the Invention]
[0008] The linear motion guide unit described above ensures smooth sliding of the slider. [Brief explanation of the drawing]
[0009] [Figure 1] Figure 1 is a schematic perspective view showing a linear motion guide unit in Embodiment 1 of the present disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view obtained when the section is cut along the line indicated by arrow II-II in Figure 1. [Figure 3]Figure 3 is an enlarged front view showing the region including the slider holding plate, which will be described later, included in the linear motion guide unit shown in Figure 1. [Figure 4] Figure 4 is a schematic cross-sectional view showing a portion of the slider included in the linear motion guide unit shown in Figure 1. [Figure 5] Figure 5 is a schematic perspective view of the retaining plate. [Figure 6] Figure 6 is an enlarged view of the region indicated by VI in Figure 5. [Figure 7] Figure 7 is an exploded perspective view of the retaining member, including the retaining plate. [Figure 8] Figure 8 is a schematic side view of the retaining plate. [Figure 9] Figure 9 is a schematic side view of the retaining plate. [Figure 10] Figure 10 is a schematic cross-sectional view of the retaining plate. [Figure 11] Figure 11 is a schematic, enlarged view showing the areas around the first and second tongue-shaped portions of the retaining plate. [Figure 12] Figure 12 is a schematic, enlarged view showing the areas around the first and second tongue-shaped portions of the retaining plate. [Modes for carrying out the invention]
[0010] [Summary of the Embodiment] The linear motion guide unit of this disclosure comprises a rail having a first raceway surface extending in the longitudinal direction, a slider mounted to the rail so as to be movably relative to the rail and having a second raceway surface facing the first raceway surface, and a plurality of rollers as rolling elements that roll along a track formed by the first raceway surface and the second raceway surface. The slider includes a casing having a first circulation path parallel to the trackway and a first guide surface and a second raceway surface that contact a first end surface located on one side of the roller to guide the roller, an end cap disposed on one side in the longitudinal direction of the casing and having a second circulation path connecting the trackway and the first circulation path, and a retaining member for holding the roller in the casing. Each roller circulates along an annular path formed by the trackway, the first circulation path and the second circulation path. The retaining member includes a retaining plate having a longitudinal shape and a second guide surface that contacts a second end surface located on the other side of the roller to guide the roller, and a mounting mechanism for attaching the retaining plate to the casing side. The retaining plate is provided with a first tongue-shaped portion which includes a part of the second guide surface, with its longitudinal end being the first fixed end and its longitudinal center being the first free end, and a second tongue-shaped portion which includes a part of the second guide surface, with its longitudinal center being the second fixed end and its longitudinal end being the second free end. The first tongue-shaped portion includes a first raised portion provided on the second guide surface so as to protrude toward the first guide surface. The second tongue-shaped portion includes a second raised portion provided on the second guide surface so as to protrude toward the first guide surface.
[0011] The inventors noticed that when a roller moves from a direction change path (an unloaded area where no load is applied to the roller) to a track path (a loaded area where a load is applied to the roller), the roller's posture tilts, causing roller skew, which can lead to increased sliding resistance and heat generation in the slider. After diligent research, they conceived the following configuration. Specifically, they considered correcting the roller's posture within the track path by appropriately pressing the end face of the roller against the second guide surface included in the holding plate of the holding member, thereby correcting the roller's posture as it enters the track path.
[0012] According to the linear motion guide unit of this disclosure, the retaining plate is provided with a first tongue-shaped portion having the above configuration. In this case, the roller enters the load area from the first fixed end side of the first tongue-shaped portion. Since the first tongue-shaped portion includes a first raised portion, the roller can be moved while being pressed toward the first guide surface side by the elastic deformation of the first tongue-shaped portion. Here, in the first tongue-shaped portion, the roller moves from the first fixed end side to the first free end side, but as it moves toward the first free end side, the pressing force of the roller due to elastic deformation decreases. According to the linear motion guide unit of this disclosure, the retaining plate is provided with a second tongue-shaped portion having the above configuration. In the second tongue-shaped portion, in the longitudinal direction, the unloaded area side is the second free end and the load area side is the second fixed end, the opposite to the first tongue-shaped portion. Since the second tongue-shaped portion includes a second raised portion, the roller can be moved while being pressed toward the first guide surface side by the elastic deformation of the second tongue-shaped portion. In this case, the roller moves toward the second fixed end of the second tongue-shaped section, that is, toward the root side of the second tongue-shaped section. As a result, even in regions where the pressing force on the first tongue-shaped section is small, the second tongue-shaped section, with its high pressing force due to elastic deformation, can strongly press the roller toward the first guide surface as it moves. Therefore, when the roller moves toward the center in the longitudinal direction, its orientation can be properly corrected and guided. As a result, the occurrence of skew in the track can be suppressed, and the smooth sliding of the slider can be ensured. Such a linear motion guide unit can press the roller over a wide area in the longitudinal direction, and is therefore particularly effective when the diameter of the roller is relatively large.
[0013] In the linear motion guide unit described above, the first tongue-shaped portion and the second tongue-shaped portion may each be provided in pairs with a gap in the longitudinal direction. By doing so, smooth sliding of the slider can be ensured on both sides of the linear motion guide unit in the longitudinal direction.
[0014] In the linear guide unit described above, the first tongue-shaped portion and the second tongue-shaped portion may be arranged at intervals in the rotational axis direction of the roller that rolls on the first guide surface and the second guide surface. By doing so, in the longitudinal direction of the holding plate, the region where the first tongue-shaped portion is located and the region where the second tongue-shaped portion is located can be overlapped. Then, the roller can be moved without interrupting the pressing force of the roller by the first tongue-shaped portion and the second tongue-shaped portion that each perform elastic deformation. Therefore, the occurrence of skew can be more reliably suppressed, and smooth sliding of the slider can be more reliably ensured.
[0015] In the linear guide unit described above, a gap may be provided around the first tongue-shaped portion and the second tongue-shaped portion, excluding the regions where the first fixed end and the second fixed end are located. By doing so, when the first tongue-shaped portion and the second tongue-shaped portion elastically deform starting from each fixed end, the other part of the holding plate, that is, the part where the first tongue-shaped portion and the second tongue-shaped portion are not provided, can greatly reduce the risk of interfering with the first tongue-shaped portion and the second tongue-shaped portion. Therefore, the occurrence of skew can be more reliably suppressed, and smooth sliding of the slider can be more reliably ensured.
[0016] In the linear guide unit described above, the length of the second tongue-shaped portion in the longitudinal direction may be longer than the length of the first tongue-shaped portion in the longitudinal direction. By doing so, the elastic deformation of the second tongue-shaped portion with the second fixed end on the central side in the longitudinal direction and the second free end on the end side in the longitudinal direction can be made appropriate, and the movement of the roller from the second free end side can be made smoother. Therefore, smooth sliding of the slider can be more reliably ensured.
[0017] In the linear motion guide unit described above, the position of the most protruding region of the first raised portion and the position of the most protruding region of the second raised portion may overlap in the longitudinal direction. By doing so, the pressing of the roller by the first raised portion included in the first tongue-shaped portion and the pressing of the roller by the second raised portion included in the second tongue-shaped portion can be made to overlap in the longitudinal direction. This reduces the amount of deflection of the first tongue-shaped portion 61a and the second tongue-shaped portion 62a, which have different pivot points, and even if one of the protruding regions moves away from the roller, the other protruding region can still press against the roller. Therefore, the pressing of the roller by the first tongue-shaped portion and the pressing of the roller by the second tongue-shaped portion can more reliably correct the roller's posture and suppress the occurrence of skew. As a result, smooth sliding of the slider can be ensured even more reliably.
[0018] [Specific examples of embodiments] Next, an example of a specific embodiment of the linear motion guide unit of this disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numerals, and their descriptions will not be repeated.
[0019] (Embodiment 1) First, Embodiment 1, which is an embodiment of the present disclosure, will be described. Figure 1 is a schematic perspective view showing the linear motion guide unit in Embodiment 1 of the present disclosure. Figure 2 is a schematic cross-sectional view taken along the line indicated by arrow II-II in Figure 1. In Figure 1 and the following figures, the X direction indicates the width direction of the linear motion guide unit, the Y direction indicates the longitudinal direction of the linear motion guide unit, and the Z direction indicates the thickness direction (height direction) of the linear motion guide unit. The X, Y, and Z directions are orthogonal to each other. Figure 2 is a cross-sectional view taken along a plane perpendicular to the Y direction, i.e., the XZ plane. Figure 3 is an enlarged front view showing the region including the slider holding plate, which will be described later, included in the linear motion guide unit shown in Figure 1. Figure 4 is a schematic cross-sectional view showing a part of the slider included in the linear motion guide unit shown in Figure 1.
[0020] Referring to Figures 1 to 4, the linear motion guide unit 10a according to Embodiment 1 of this disclosure includes a rail 11a which is a track rail, a slider 21a, and a plurality of rollers 20a, 20b, 20c, and 20d which are rolling elements. The rail 11a is configured to extend straight in the longitudinal direction, which is the Y direction. By including a plurality of rollers 20a, 20b, 20c, and 20d as rolling elements, the linear motion guide unit 10a according to Embodiment 1 can achieve a larger rated load while keeping the size compact, compared to, for example, a case where the rolling elements are balls. In this embodiment, the linear motion guide unit 10a is a so-called four-row linear motion guide unit. Note that the rollers 20a and 20b each include rolling surfaces 28a and 28b, first end faces 51a and 51b located on one side in the direction of the rotation axis of the rollers 20a and 20b, and second end faces 52a and 52b located on the other side in the direction of the rotation axis. Similarly, rollers 20c and 20d also include a rolling surface, a first end face located on one side in the direction of the rotation axis of rollers 20c and 20d, and a second end face located on the other side in the direction of the rotation axis.
[0021] First, the configuration of the rail 11a will be described. The rail 11a includes an upper rail end surface 12a and a lower rail end surface 12b arranged at a distance in the Z direction, a first rail side surface 13a and a second rail side surface 13b arranged at a distance in the X direction, and a front rail end surface 14a and a rear rail end surface 14b arranged at a distance in the Y direction. That is, the rail 11a includes a first rail side surface 13a and a 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 and 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. For example, the width of the rail 11a is selected to be 53 mm.
[0022] The first track groove 15a is composed of first track surfaces 16a and 16b and a side wall surface 17a. The first track surface 16a is inclined with respect to the XY plane and is located on the side of the upper end surface 12a of the rail. The first track surface 16b is inclined with respect to the XY plane and is located on the side of the lower end surface 12b of the rail. The side wall surface 17a is provided in conjunction with both the first track surface 16a and the first track surface 16b. The first track groove 15b is also composed of first track surfaces 16c and 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 located on the side of the upper end surface 12a of the rail. The first track surface 16d is inclined with respect to the XY plane and is located on the side of the lower end surface 12b of the rail. The side wall surface 17b is provided in conjunction with both the first track surface 16c and the first track surface 16d. In other words, the rail 11a includes first track surfaces 16a, 16b, 16c, and 16d that extend in the longitudinal direction. A linear motion guide unit 10a including such a rail 11a is suitably used in machine tools, assembly equipment, conveying machines, and the like.
[0023] The rail 11a is provided with a plurality of through holes 18 that penetrate in the Z direction from the upper end surface 12a of the rail to the lower end surface 12b of the rail. The plurality of through holes 18 are spaced apart in the Y direction. The through holes 18 are effectively utilized, for example, when attaching the rail 11a to a predetermined location when using the linear motion guide unit 10a.
[0024] Next, the configuration of the slider 21a will be described. The slider 21a is mounted so as to be movable relative to the rail 11a. In this embodiment, the slider 21a is slidably straddled over the rail 11a. The slider 21a is provided with a recess 24a that is recessed in the Z direction, and the rail 11a is mounted so as to be fitted into this recess 24a. That is, the slider 21a is mounted so as to straddle the rail 11a and is movable in the Y direction.
[0025] The slider 21a includes a casing 22a, a pair of end caps 23a, 23b, specifically a first end cap 23a and a second end cap 23b, and retaining members 41a, 41b that hold the rollers 20a, 20b, 20c, 20d to the casing 22a. The configuration of the retaining members 41a, 41b will be described in detail later. The first end cap 23a is positioned on one side of the casing 22a in the longitudinal direction, specifically on the rail front end face 14a side of the casing 22a in the longitudinal direction. The second end cap 23b is positioned on the other side of the casing 22a in the longitudinal direction, specifically on the rail rear end face 14b side of the casing 22a in the longitudinal direction. In other words, the slider 21a includes a pair of end caps 23a, 23b positioned on both sides of the casing 22a in the longitudinal direction. The first end cap 23a is provided with a through hole that penetrates in the Y direction. Both the first end cap 23a and the second end cap 23b are so-called plate-shaped with their longitudinal direction as the thickness direction. The first end cap 23a is connected to the casing 22a by multiple bolts using the through hole. The second end cap 23b is connected to the casing 22a by multiple bolts using the through hole. The end cap 23a is also provided with a supply hole (not shown) for supplying lubricating oil. The same applies to the end cap 23b.
[0026] The slider 21a includes an end seal 27a positioned on one longitudinal side of the first end cap 23a, and a lubricating member (not shown) for applying lubricating oil. The end seal 27a and 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 lubricating member. The casing 22a is provided with a plurality of mounting holes 29 recessed in the Z direction. In this embodiment, there are nine mounting holes 29. The nine mounting holes 29 are spaced apart in the X and Y directions, respectively, and are used, for example, when connecting the slider 21a to other members.
[0027] The casing 22a includes second raceway surfaces 32a, 32b, 32c, and 32d that are opposite to the first raceway surfaces 16a, 16b, 16c, and 16d, respectively. The track 31a on which the roller 20a rolls is composed of the first raceway surface 16a and the second raceway surface 32a. The track 31b on which the roller 20b rolls is composed of the first raceway surface 16b and the second raceway surface 32b. The track 31c on which the roller 20c rolls is composed of the first raceway surface 16c and the second raceway surface 32d. The track 31d on which the roller 20d rolls is composed of the first raceway surface 16d and the second raceway surface 32d.
[0028] The casing 22a is provided with first circulation paths 33a, 33b, 33c, and 33d, which run parallel to the track paths 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 a first dividing member 35a and a second dividing member 36a, is arranged inside the first circulation path 33a. Multiple rollers 20a move inside the sleeve 34a. Similarly, a hollow cylindrical sleeve 34b, formed by combining a first dividing member 35b and a second dividing member 36b, is arranged inside the first circulation path 33b. A hollow cylindrical sleeve 34c, formed by combining a first dividing member 35c and a second dividing member 36c, is arranged inside the first circulation path 33c. A hollow cylindrical sleeve 34d, formed by combining a first dividing member 35d and a second dividing member 36d, is arranged inside the first circulation path 33d.
[0029] The casing 22a includes first guide surfaces 39a, 39b, 39c, and 39d that contact the first end faces 51a and 51b located on one side of the rollers 20a, 20b, 20c, and 20d, and guide the rollers 20a, 20b, 20c, and 20d.
[0030] The first end cap 23a is provided with a second circulation path 37a (see Figure 4 in particular). The second circulation path 37a is also called a direction change path. The second circulation path 37a has an arc-shaped recess in the thickness direction (Y direction) of the first end cap 23a so as to allow multiple rollers 20a to move. Spacers 30a are used to make the second circulation path 37a arc-shaped. The second circulation path 37a connects the track 31a and the first circulation path 33a. The first end cap 23a includes a second circulation path connecting the track 31b and the first circulation path 33b, a second circulation path connecting the track 31c and the first circulation path 33c, and a second circulation path connecting the track 31d and the first circulation path 33d. Furthermore, the second end cap 23b, like the first end cap 23a, includes a second circulation path connecting track 31a and the first circulation path 33a, a second circulation path connecting track 31b and the first circulation path 33b, a second circulation path connecting track 31c and the first circulation path 33c, and a second circulation path connecting track 31d and the first circulation path 33d. Multiple rollers 20a circulate in an annular path formed by track 31a, the second circulation path of the second end cap 23b, the first circulation path 33a, and the second circulation path 37a of the first end cap 23a. Multiple rollers 20b circulate in an annular path formed by track 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. Multiple rollers 20c circulate in a ring path formed by the track 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. Multiple rollers 20d circulate in a ring path formed by the track 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.
[0031] Next, the configurations of the retaining members 41a and 41b that hold the rollers 20a, 20b, 20c, and 20d in the casing 22a will be described. Retaining member 41a includes a retaining plate 42a and a mounting mechanism 49a. Retaining member 41b includes a retaining plate 42b and a mounting mechanism including a rod-shaped first fixing member 44b. The configuration of retaining member 41b is the same as that of retaining member 41a, so its description will be omitted. Figure 5 is a schematic perspective view of the retaining plate 42a. Figure 6 is an enlarged view of the area indicated by VI in Figure 5. Figure 7 is an exploded perspective view of the retaining member 41a including the retaining plate 42a. Figure 8 is a schematic side view of the retaining plate 42a. Figure 9 is a schematic side view of the retaining plate 42a. Figure 10 is a schematic cross-sectional view of the retaining plate 42a. Figure 11 is an enlarged schematic view showing the areas around the first and second tongue-shaped portions of the retaining plate 42a. Figure 12 is a schematic, enlarged view showing the areas around the first and second tongue-shaped portions of the retaining plate 42a.
[0032] Referring to Figures 5 to 12, the retaining member 41a includes a retaining plate 42a, a longitudinally elongated rod-shaped first fixing member 44a, and a pair of second fixing members 45a, 45b spaced apart in the longitudinal direction (see Figure 7 in particular). The retaining plate 42a is substantially triangular prism-shaped. Both longitudinal ends 54a, 54b of the retaining plate 42a are flat. The retaining plate 42a includes second guide surfaces 46a, 46b that contact the second end faces 52a, 52b located on the other side of the rollers 20a, 20b, respectively, to guide the rollers 20a, 20b. The retaining plate 42a is also provided with a groove 47a that is recessed to accommodate the first fixing member 44a. The groove 47a has a shape that extends along the longitudinal direction. Furthermore, the retaining plate 42a is provided with through holes 48a and 48b for accommodating the second fixing members 45a and 45b, respectively. The through holes 48a and 48b are provided as a pair, spaced apart in the longitudinal direction. The retaining plate 42a is attached to the casing 22a side by connecting it with bolts (not shown) in the direction shown by the dashed line in Figure 7, with the first fixing member 44a accommodated in the groove 47a and the second fixing members 45a and 45b accommodated in the through holes 48a and 48b, respectively. The first fixing member 44a and the second fixing members 45a and 45b function as an attachment mechanism 49a for attaching the retaining plate 42a to the casing 22a side.
[0033] The retaining plate 42a is provided with a first tongue-shaped portion 61a and a second tongue-shaped portion 62a. The first tongue-shaped portion 61a includes a part of the second guide surface 46a. Specifically, the part of the first tongue-shaped portion 61a facing the first guide surface 39a is part of the second guide surface 46a. The first tongue-shaped portion 61a has a first fixed end 63a on the longitudinal end 54a side of the retaining plate 42a, and a first free end 64a on the longitudinal center side of the retaining plate 42a. The first tongue-shaped portion 61a includes a first raised portion 65a provided on the second guide surface 46a so as to protrude toward the first guide surface 39a side. The first raised portion 65a includes a first region 71a, a second region 72a, and a third region 73a in longitudinal order from the part where the first fixed end 63a is located. Specifically, the first region 71a includes the first fixed end 63a, the third region 73a includes the first free end 64a, and the second region 72a is located between the first region 71a and the third region 73a. The first region 71a is composed of an inclined surface whose protrusion gradually increases from the first fixed end 63a toward the longitudinal center, i.e., the second region 72a. The second region 72a is composed of a plane and is the region that is most raised at the longitudinal center of the first tongue-shaped portion 61a. The third region 73a is composed of an inclined surface whose protrusion gradually decreases from the longitudinal center, i.e., from the second region 72a toward the first free end 64a. The first tongue-shaped portion 61a is elastically deformable along a direction perpendicular to the second guide surface 46a, starting from the first fixed end 63a.
[0034] The second tongue-shaped portion 62a also includes a part of the second guide surface 46a. Specifically, the part of the second tongue-shaped portion 62a facing the first guide surface 39a is part of the second guide surface 46a. The second tongue-shaped portion 62a has a second fixed end 66a on the longitudinal center side of the retaining plate 42a, and a second free end 67a on the longitudinal end 54a side of the retaining plate 42a. The second tongue-shaped portion 62a includes a second raised portion 68a provided on the second guide surface 46a so as to protrude toward the first guide surface 39a. The second raised portion 68a includes a fourth region 74a, a fifth region 75a, and a sixth region 76a in longitudinal order from the part where the second fixed end 66a is located. Specifically, the fourth region 74a includes the second fixed end 66a, the sixth region 76a includes the second free end 67a, and the fifth region 75a is located between the fourth region 74a and the sixth region 76a. The fourth region 74a is composed of an inclined surface whose protrusion gradually increases from the second fixed end 66a toward the longitudinal end 54a, i.e., toward the fifth region 75a. The fifth region 75a is composed of a plane and is the most raised region at the longitudinal center of the second tongue-shaped portion 62a. The sixth region 76a is composed of an inclined surface whose protrusion gradually decreases from the longitudinal end 54a, i.e., toward the second free end 67a, toward the fifth region 75a. The second tongue-shaped portion 62a is elastically deformable along a direction perpendicular to the second guide surface 46a, starting from the second fixed end 66a.
[0035] A gap 69a is provided around the first tongue-shaped portion 61a and the second tongue-shaped portion 62a, except for the areas where the first fixed end 63a and the second fixed end 66a are located. The first tongue-shaped portion 61a and the second tongue-shaped portion 62a are spaced apart in the direction of the rotation axis of the roller 20a that rolls on the first guide surface 39a and the second guide surface 46a. That is, a gap 69a is also provided between the first tongue-shaped portion 61a and the second tongue-shaped portion 62a. The longitudinal length L2 of the second tongue-shaped portion 62a is longer than the longitudinal length L1 of the first tongue-shaped portion 61a. In addition, the position of the second region 72a, which is the most protruding area of the first raised portion 65a, and the position of the fifth region 75a, which is the most protruding area of the second raised portion 68a, overlap in the longitudinal direction. Furthermore, the amount of protrusion (protrusion height) of the second region 72a and the amount of protrusion (protrusion height) of the fifth region 75a are set to be equal.
[0036] In this embodiment, the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are provided in pairs, spaced apart in the longitudinal direction. Specifically, the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are provided in pairs near both ends 54a and 54b in the longitudinal direction of the retaining plate 42a. In addition, the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are also provided on the second guide surface 46b side. In other words, the retaining plate 42a is provided with a total of four first tongue-shaped portions 61a and four second tongue-shaped portions 62a each.
[0037] According to the linear motion guide unit 10a described above, the retaining plate 42a is provided with a first tongue-shaped portion 61a having the above configuration. In this case, the roller 20a enters the load area from the first fixed end 63a side of the first tongue-shaped portion 61a. Since the first tongue-shaped portion 61a includes a first raised portion 65a, the roller 20a can be moved while being pressed toward the first guide surface 39a side by the elastic deformation of the first tongue-shaped portion 61a. Here, in the first tongue-shaped portion 61a, the roller 20a moves from the first fixed end 63a side toward the first free end 64a side, but as it moves toward the first free end 64a side, the pressing force of the roller 20a due to elastic deformation decreases. According to the linear motion guide unit 10a of this disclosure, the retaining plate 42a is provided with a second tongue-shaped portion 62a having the above configuration. In the second tongue-shaped portion 62a, in the longitudinal direction, the unloaded area side is the second free end 67a, and the loaded area side is the second fixed end 66a, the opposite to the first tongue-shaped portion 61a. Since the second tongue-shaped portion 62a includes the second raised portion 68a, the elastic deformation of the second tongue-shaped portion 62a allows the roller 20a to move while being pressed toward the first guide surface 39a. In this case, the roller 20a moves toward the second fixed end 66a side of the second tongue-shaped portion 62a, that is, toward the base side of the second tongue-shaped portion 62a. As a result, even in areas where the pressing force is small in the first tongue-shaped portion 61a, the second tongue-shaped portion 62a, which has a high pressing force on the roller 20a due to elastic deformation, allows the roller 20a to move while being strongly pressed toward the first guide surface 39a. Therefore, when the roller 20a moves toward the center in the longitudinal direction, the orientation of the roller 20a can be properly corrected and guided. As a result, skew in the track 31a can be suppressed, ensuring smooth sliding of the slider 21a.
[0038] In this embodiment, within the tolerance range of the machining process and the preload range, there is a possibility that the position at which the switch from the unloaded area to the loaded area may be slightly different for each linear motion guide unit 10a. However, even if the switching position is slightly different, the linear motion guide unit 10a having the first tongue-shaped portion 61a and the second tongue-shaped portion 62a as described above can reliably press against the end face of the roller 20a, thereby suppressing the occurrence of skew in the track path 31a and ensuring the smooth sliding of the slider 21a.
[0039] In this embodiment, the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are provided in pairs, spaced apart in the longitudinal direction. Therefore, smooth sliding of the slider 21a can be ensured on both sides of the linear motion guide unit 10a in the longitudinal direction.
[0040] In this embodiment, the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are spaced apart in the direction of the rotation axis of the roller 20a that rolls on the first guide surface 39a and the second guide surface 46a. Therefore, in the longitudinal direction of the retaining plate 42a, the region where the first tongue-shaped portion 61a is located and the region where the second tongue-shaped portion 62a is located can overlap. As a result, the roller 20a can be moved without interruption in the pressing force applied to the roller 20a by the first tongue-shaped portion 61a and the second tongue-shaped portion 62a, which undergo elastic deformation. Therefore, the occurrence of skew can be suppressed more reliably, and the smooth sliding of the slider 21a can be more reliably ensured.
[0041] In this embodiment, a gap 69a is provided around the first tongue-shaped portion 61a and the second tongue-shaped portion 62a, except for the area where the first fixed end 63a and the second fixed end 66a are located. Therefore, when the first tongue-shaped portion 61a and the second tongue-shaped portion 62a elastically deform starting from each fixed end, the risk of interference between the other parts of the retaining plate 42a, i.e., the parts where the first tongue-shaped portion 61a and the second tongue-shaped portion 62a are not provided, and the first tongue-shaped portion 61a and the second tongue-shaped portion 62a can be greatly reduced. Consequently, the occurrence of skew can be suppressed more reliably, and the smooth sliding of the slider 21a can be more reliably ensured.
[0042] In this embodiment, the longitudinal length of the second tongue-shaped portion 62a is longer than the longitudinal length of the first tongue-shaped portion 61a. Therefore, by appropriately adjusting the elastic deformation of the second tongue-shaped portion 62a, with the second fixed end 66a on the longitudinal center side and the second free end 67a on the longitudinal end 54a side, the movement of the roller 20a from the second free end 67a side can be made smoother. Consequently, the smooth sliding of the slider 21a can be more reliably ensured.
[0043] In this embodiment, the position of the second region 72a, which is the most protruding area of the first raised portion 65a, and the position of the fifth region 75a, which is the most protruding area of the second raised portion 68a, overlap in the longitudinal direction. Therefore, the pressing of the roller 20a by the first raised portion 65a included in the first tongue-shaped portion 61a and the pressing of the roller 20a by the second raised portion 68a included in the second tongue-shaped portion 62a can be made to overlap in the longitudinal direction. This reduces the amount of deflection of the first tongue-shaped portion 61a and the second tongue-shaped portion 62a, which have different pivot points, and even if one of the protruding areas moves away from the roller, the other protruding area can still press against the roller. Therefore, the pressing of the roller 20a by the first tongue-shaped portion 61a and the pressing of the roller 20a by the second tongue-shaped portion 62a can more reliably correct the posture of the roller 20a and suppress the occurrence of skew. As a result, smooth sliding of the slider 21a can be ensured even more reliably.
[0044] (Other embodiments) In the above embodiment, the first tongue-shaped portion and the second tongue-shaped portion are spaced apart in the direction of the rotation axis of the roller that rolls on the first guide surface and the second guide surface. However, the invention is not limited to this configuration, and the first tongue-shaped portion and the second tongue-shaped portion may be arranged side by side in the longitudinal direction. In this case, the longitudinal distance between the first tongue-shaped portion and the second tongue-shaped portion may be smaller than the diameter of the roller. By doing so, in the region where the first tongue-shaped portion and the second tongue-shaped portion are provided, the first tongue-shaped portion or the second tongue-shaped portion can be brought into contact with the roller, thereby actively pushing the roller. Furthermore, the configuration may not include any gaps around the first tongue-shaped portion and the second tongue-shaped portion. Also, the positions of the first tongue-shaped portion and the second tongue-shaped portion in the Z direction may be reversed. In addition, the longitudinal length of the second tongue-shaped portion may be shorter than the longitudinal length of the first tongue-shaped portion, and the longitudinal lengths of the second tongue-shaped portion and the first tongue-shaped portion may be equal.
[0045] Furthermore, in the above embodiment, a pair of first tongue-shaped portions and a pair of second tongue-shaped portions are provided in the longitudinal direction, but the invention is not limited to this, and the first tongue-shaped portions and the second tongue-shaped portions may be provided only on one side in the longitudinal direction.
[0046] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the present invention is defined by the claims and is intended to include all modifications in the sense and scope equivalent to the claims. [Explanation of symbols]
[0047] 10a Linear guide unit, 11a Rail, 12a Upper end face of rail, 12b Lower end face of rail, 13a Side of first rail, 13b Side of second rail, 14a Front end face of rail, 14b Rear end face of rail, 15a, 15b First track groove, 16a, 16b, 16c, 16d First track surface, 17a, 17b Side wall surface, 18, 48a, 48b Through hole, 20a, 20b, 20c, 20d Roller, 21a Slider, 22a Casing, 23a End cap (first end cap), 23b End cap (second end cap), 24a Recess, 27a, 27b End seal, 28a, 28b Rolling surface, 29 Mounting hole, 30a Spacer, 31a, 31b, 31c, 31d Track, 32a,32b,32c,32d Second track surface, 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 Second circulation path, 39a,39b,39c,39d First guide surface, 41a,41b Holding member, 42a,42b Holding plate, 44a,44b First fixing member, 45a,45b Second fixing member, 46a,46b Second guide surface, 47a Groove, 49a Mounting mechanism, 51a,51b First end face, 52a,52b Second end face, 54a,54b End, 61a First tongue-shaped portion, 62a Second tongue-shaped portion, 63a First fixed end, 64a First free end, 65a First raised portion, 66a Second fixed end, 67a Second free end, 68a Second raised portion, 69a Gap, 71a First region, 72a Second region, 73a Third region, 74a Fourth region, 75a Fifth region, 76a Sixth region.
Claims
1. A rail having a first track surface extending in the longitudinal direction, A slider is attached to the rail so as to be movable relative to it and has a second track surface facing the first track surface, The system comprises a plurality of rollers, which are rolling elements that roll along a track formed by the first and second raceway surfaces, The aforementioned slider is A casing is provided which includes a first circulation path parallel to the aforementioned track path, a first guide surface that contacts a first end face located on one side of the roller and guides the roller, and the second track surface. An end cap is provided on one side of the casing in the longitudinal direction, and a second circulation path is provided that connects the track path and the first circulation path. The roller includes a holding member that holds the roller in the casing, Each of the rollers circulates along an annular path formed by the track, the first circulation path, and the second circulation path. The aforementioned retaining member is A retaining plate having a shape extending in the longitudinal direction and having a second guide surface that contacts a second end surface located on the other side of the roller and guides the roller, The mounting mechanism includes for attaching the retaining plate to the casing side, The aforementioned retaining plate includes: A first tongue-shaped portion includes a part of the second guide surface, the longitudinal end of the retaining plate is the first fixed end, and the longitudinal center of the retaining plate is the first free end, A second tongue-shaped portion is provided, which includes a part of the second guide surface, with the central side in the longitudinal direction of the retaining plate being the second fixed end and the end side in the longitudinal direction of the retaining plate being the second free end. The first tongue-shaped portion includes a first raised portion provided on the second guide surface so as to protrude toward the first guide surface, The linear motion guide unit includes a second tongue-shaped portion which is provided on the second guide surface so as to protrude toward the first guide surface.
2. The linear motion guide unit according to claim 1, wherein the first tongue-shaped portion and the second tongue-shaped portion are each provided in pairs at intervals in the longitudinal direction.
3. The linear motion guide unit according to claim 1 or claim 2, wherein the first tongue-shaped portion and the second tongue-shaped portion are spaced apart in the direction of the rotation axis of the roller that rolls on the first guide surface and the second guide surface.
4. A linear motion guide unit according to claim 1 or 2, wherein a gap is provided around the first tongue-shaped portion and the second tongue-shaped portion, except in the region where the first fixed end and the second fixed end are located.
5. The linear motion guide unit according to claim 1 or claim 2, wherein the longitudinal length of the second tongue-shaped portion is longer than the longitudinal length of the first tongue-shaped portion.
6. The linear motion guide unit according to claim 1 or claim 2, wherein the position of the most protruding region of the first raised portion and the position of the most protruding region of the second raised portion overlap in the longitudinal direction.