Linear motion guide unit

Abstract

This linear motion guide unit comprises: a rail having a first raceway surface extending in a first direction that is the longitudinal direction; a slider attached to the rail so as to be relatively movable in the first direction and having a second raceway surface facing the first raceway surface; and a roller in the form of a plurality of rolling elements that roll on a raceway path constituted by the first raceway surface and the second raceway surface. The slider includes: a casing including the second raceway surface and a first guide surface to come into contact with a first end surface located at the end on one side of the roller to guide the roller; a circulation module, which is provided with a first circulation path parallel to the raceway path and a second circulation path connecting the raceway path and the first circulation path, and which is attached to the casing; and a roller holding member that is attached to the circulation module and causes the casing to hold the roller. The roller holding member includes: a roller holding claw that comes into contact with a part of the rolling surface of the roller in the raceway path to hold the roller; a second guide surface that comes into contact with a second end surface located on the end on the other side of the roller to guide the roller; and a scoop part that comes into contact with the rolling surface of the roller to guide the roller to the second circulation path when the roller moves from the raceway path to the second circulation path. The roller holding member is integrally formed.

Description

Linear motion guide unit

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

[0002] A linear motion guide device having a cage that holds rolling cylindrical rollers on the slider side is known (see, for example, Patent Document 1). The cage included in such a linear motion guide device is formed of a resin material.

[0003] Japanese Patent Application Laid-Open No. 2005-114095

[0004] In a linear motion guide unit that uses rollers as rolling elements, it is required to prevent the rollers from tipping over during the movement of the rollers when the slider moves linearly back and forth, and to allow the rollers to roll stably. Especially recently, miniaturization of the linear motion guide unit has been demanded. In such a case, each component constituting the slider becomes smaller. As a result, the possibility that the rollers will catch on the steps generated when a plurality of components are combined or the chamfers provided at the corners of each component increases, and the risk that the rollers will tip over becomes higher. In such a situation, it becomes difficult to move the slider linearly back and forth stably.

[0005] Therefore, one of the objectives is to provide a linear motion guide unit that can move the slider linearly back and forth stably.

[0006] A linear motion guide unit according to this disclosure comprises a rail having a first raceway surface extending in a first longitudinal direction, a slider mounted on the rail so as to be movable relative to the first raceway surface and having a second raceway surface facing the first raceway surface, and a plurality of rollers as rolling elements that roll along a track composed of the first raceway surface and the second raceway surface. The slider includes a casing including a first guide surface and a second raceway surface that contact a first end surface located on one end side of the roller to guide the roller, a circulation module attached to the casing provided with a first circulation path parallel to the trackway and a second circulation path connecting the trackway and the first circulation path, and a roller holding member attached to the circulation module for holding the roller in the casing. The roller holding member includes a roller holding claw that contacts a portion of the rolling surface of the roller in the track to hold the roller, a second guide surface that contacts a second end surface located on the other end side of the roller to guide the roller, and a scoop portion that contacts the rolling surface of the roller to guide the roller to the second circulation path when the roller moves from the track to the second circulation path. The roller holding member is constructed as a single unit.

[0007] According to the above linear motion guide unit, the slider can be made to move back and forth in a straight line stably.

[0008] Figure 1 is a schematic perspective view of a linear guide unit in Embodiment 1 of the present disclosure. Figure 2 is a schematic front view of the linear guide unit shown in Figure 1. Figure 3 is a schematic top view of the linear guide unit shown in Figure 1. Figure 4 is a schematic side view of the linear guide unit shown in Figure 1. Figure 5 is a schematic cross-sectional view showing a part of the linear guide unit shown in Figure 2. Figure 6 is a schematic cross-sectional view showing a part of the linear guide unit shown in Figure 2. Figure 7 is a schematic cross-sectional view showing an enlarged part of the linear guide unit shown in Figure 5. Figure 8 is an exploded perspective view of a slider included in the linear guide unit shown in Figure 1, which will be described later. Figure 9 is a schematic front view of the casing. Figure 10 is an enlarged view showing an enlarged part of the casing shown in Figure 9. Figure 11 is a schematic perspective view showing a pair of circulation modules combined. Figure 12 is a schematic cross-sectional view showing a part of the pair of circulation modules shown in Figure 11. Figure 13 is a schematic perspective view of the entire circulation module. Figure 14 is a schematic perspective view of the roller holding member. Figure 15 is a schematic perspective view of the roller holding member. Figure 16 is an enlarged view showing a portion of the roller holding member shown in Figures 14 and 15. Figure 17 is an exploded perspective view of the slider 31b included in the linear guide unit in Embodiment 2 of this disclosure. Figure 18 is a schematic front view of the casing included in the linear guide unit in Embodiment 2. Figure 19 is a schematic perspective view of the circulation module included in the linear guide unit in Embodiment 2.

[0009] [Outline of Embodiments] The linear motion guide unit of the present disclosure comprises a rail having a first raceway surface extending in a first longitudinal direction, a slider attached to the rail so as to be movable relative to the first raceway surface and having a second raceway surface facing the first raceway surface, and a plurality of rollers as rolling elements that roll along a track composed of the first raceway surface and the second raceway surface. The slider includes a casing including a first guide surface and a second raceway surface that contact a first end surface located on one end side of the roller to guide the roller, a circulation module attached to the casing provided with a first circulation path parallel to the trackway and a second circulation path connecting the trackway and the first circulation path, and a roller holding member attached to the circulation module to hold the roller in the casing. The roller holding member includes a roller holding claw that contacts a portion of the rolling surface of the roller in the track to hold the roller, a second guide surface that contacts a second end surface located on the other end side of the roller to guide the roller, and a scoop portion that contacts the rolling surface of the roller to guide the roller to the second circulation path when the roller moves from the track to the second circulation path. The roller holding member is constructed as a single unit.

[0010] In the linear motion guide unit with the above configuration, the slider that performs linear reciprocating motion with respect to the rail includes a casing, a circulation module, and a roller holding member. In such a linear motion guide unit, multiple rollers circulate along a path consisting of a first circulation path and a second circulation path provided in the circulation module, and a track path. With this configuration, it is easy to accurately position the circulation module with respect to the track path, and the path along which the rollers circulate can be formed with precision. Furthermore, since the roller holding member includes roller holding claws, it is easier to stably maintain the posture of the rollers on the track path compared to the case where the roller holding claws are provided on the rail side. In addition, since the roller holding member includes a second guide surface, it is possible to appropriately guide the rollers on the track path while suppressing the tilting of the rollers. Furthermore, the roller holding member includes a scoop portion that contacts the rolling surface of the roller when the roller moves from the track path to the second circulation path, guiding the roller to the second circulation path. The roller holding member is also constructed as a single unit. As a result, when the scooping section moves the roller from the track to the second circulation path, the roller will not get caught on steps or chamfers on the corners of the parts that are created by combining multiple parts. Therefore, the tipping of the roller during movement is suppressed, and the roller can be moved more smoothly. Based on the above, the linear motion guide unit can stably make the slider move in a linear reciprocating motion.

[0011] In the linear motion guide unit described above, the roller holding member may include a hook portion that protrudes in a second direction intersecting the first direction. The circulation module may be provided with a fitting portion that engages with the hook portion. By doing so, the roller holding member can be attached to the circulation module with high precision and reliability by utilizing the hook portion of the roller holding member and the fitting portion of the circulation module. Therefore, the circulation path of the roller can be formed with high precision.

[0012] In the linear motion guide unit described above, the hooking portion may include a first projection extending in a second direction and a second projection extending in a third direction that intersects both the first and second directions. By doing so, the first and second projections can be securely fitted with the fitting portion, reducing the risk of the roller holding member attached to the circulation module shifting position or detaching from the circulation module. Therefore, the roller holding member can be attached to the circulation module more securely.

[0013] In the linear motion guide unit described above, a pair of hooking portions may be provided at both ends of the roller holding member in the first direction. A pair of circulation modules may be arranged side by side in the first direction. Each of the pair of circulation modules may be provided with a fitting portion. In this way, the roller holding member can be securely attached to each of the pair of circulation modules. Therefore, more stable holding of the roller holding member can be achieved.

[0014] In the above-described linear motion guide unit, the circulation module may include a circulation box section provided with a second circulation path and positioned adjacent to the casing in the first direction, and a cylindrical section extending from the circulation box section in the first direction, with a first circulation path provided inside, and positioned within the casing. By doing so, it becomes easier to efficiently manufacture the above-described circulation module including the first and second circulation paths. Therefore, it becomes easier to improve the productivity of the linear motion guide unit.

[0015] In the linear motion guide unit described above, a pair of circulation modules may be included. The pair of circulation modules may be arranged side by side in the first direction. A first circulation path may be formed by connecting a pair of cylindrical sections. By doing so, a pair of circulation modules can be arranged on both sides of the longitudinal direction of the casing, thereby efficiently forming the first and second circulation paths. Consequently, the productivity of the linear motion guide unit can be further improved.

[0016] In the above-described linear guide unit, the circulation module may be provided with a first lubrication hole leading from the outside to a second circulation path. By doing so, lubrication can be supplied to the second circulation path from the outside using the first lubrication hole, enabling efficient additional lubrication. Therefore, convenience during additional lubrication can be improved.

[0017] In the linear guide unit described above, the linear guide unit may be configured in four rows. The first circulation path may be provided in pairs at intervals in the second direction. The first lubrication hole may extend from the second circulation path to each of the pair of first circulation paths. By doing so, it becomes easy to lubricate the pair of first circulation paths of the four-row linear guide unit using the first lubrication hole. Therefore, convenience during additional lubrication can be improved in a linear guide unit configured in four rows.

[0018] The linear motion guide unit described above may further include an end cap attached to one end of the casing in the first direction, and an end seal attached to one end of the end cap in the first direction. The end cap, end seal, and circulation module may be provided with a second lubrication hole leading from the outside to the second circulation path. In this way, lubrication can be supplied to the second circulation path from the outside using the second lubrication hole, allowing for efficient additional lubrication. Therefore, convenience during additional lubrication can be improved.

[0019] In the above-described linear motion guide unit, the material of the roller holding member may include at least one of the following: polyacetal (POM (Polyoxymethylene)), polyetheretherketone (PEEK (PolyEtherEtherKetone)), brass, and stainless steel. Such materials are suitably used as the material for the roller holding member included in the above-described linear motion guide unit.

[0020] The above linear motion guide unit may also be of the all-roller type. This allows for the inclusion of as many rollers as possible. Therefore, it becomes easier to achieve smoother linear reciprocating motion of the slider.

[0021] [Specific Examples of Embodiments] Next, a specific example of an 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.

[0022] (Embodiment 1) First, Embodiment 1, which is an embodiment of the present disclosure, will be described. Figure 1 is a schematic perspective view of the linear guide unit in Embodiment 1 of the present disclosure. Figure 2 is a schematic front view of the linear guide unit shown in Figure 1. Figure 2 is a view in the direction of arrow II shown in Figure 1. Figure 3 is a schematic top view of the linear guide unit shown in Figure 1. Figure 3 is a view in the direction of arrow III shown in Figure 1. Figure 4 is a schematic side view of the linear guide unit shown in Figure 1. Figure 4 is a view in the direction of arrow IV shown in Figure 1. Figures 5 and 6 are schematic cross-sectional views showing a part of the linear guide unit shown in Figure 2, respectively. Figure 5 corresponds to a cross-section including one sleeve portion of the casing, which will be described later, and Figure 6 corresponds to a cross-section including the other sleeve portion of the casing, which will be described later. Figure 7 is a schematic cross-sectional view showing an enlarged part of the linear guide unit shown in Figure 5. Figure 7 is an enlarged view including the portion indicated by region R1 in Figure 5. Figure 8 is an exploded perspective view of a slider, which will be described later, included in the linear guide unit shown in Figure 1. In Figure 8, the direction indicated by arrow Y is defined as the longitudinal direction of the rail (first direction) in the figures shown in Figure 1 and subsequent figures, the direction indicated by arrow X is defined as the short direction of the rail (second direction), and the direction indicated by arrow Z is defined as the height direction of the rail (thickness direction of the slider, third direction). The cross-sections shown in Figures 6 and 7 include the slider and are cross-sectional views taken when cut by a plane perpendicular to the Y direction, i.e., a plane parallel to the X-Z plane.

[0023] Referring to Figures 1, 2, 3, 4, 5, 6, 7, and 8, the linear motion guide unit 10a in Embodiment 1 includes a rail 11a which is a track rail, a slider 31a, and a plurality of rollers 21a, 21b, 21c, and 21d which are rolling elements. The rail 11a is configured to extend straight in the first direction (Y direction), which is the longitudinal direction. By including a plurality of rollers 21a, 21b, 21c, and 21d 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. Each of the rollers 21a and 21b includes rolling surfaces 22a and 22b, first end faces 23a and 23b located on one end of the roller 21a and 21b in the direction of the rotation center axis, and second end faces 24a and 24b located on the other end of the roller 21a and 21b in the direction of the rotation center axis. Similarly, each of the rollers 21c and 21d includes rolling surfaces 22c and 22d, first end faces 23c and 23d located on one end of the roller 21c and 21d in the direction of the rotation center axis, and second end faces 24c and 24d located on the other end of the roller 21c and 21d in the direction of the rotation center axis. In this embodiment, the linear motion guide unit 10a is of the all-roller type. In other words, the linear motion guide unit 10a does not include retainers that hold each roller 21a, 21b, 21c, 21d, nor separators that are placed between the rollers 21a, 21b, 21c, 21d, and is configured such that no members other than the rollers 21a, 21b, 21c, 21d are placed in the path through which each roller 21a, 21b, 21c, 21d circulates.

[0024] Rail 11a includes an upper rail end face 12a and a lower rail end face 12b spaced apart in the Z direction, a first rail side face 13a and a second rail side face 13b spaced apart in the X direction, and a front rail end face 14a and a rear rail end face 14b spaced apart in the Y direction. The first rail side face 13a and the second rail side face 13b are parallel and extend along their respective longitudinal directions (first direction and Y direction). Rail 11a includes a pair of first track grooves 15a and 15b that extend parallel to each other in their longitudinal directions. The first track groove 15a is provided on the first rail side face 13a. The first track groove 15b is provided on the second rail side face 13b.

[0025] The first track groove 15a is composed of a pair of first track surfaces 16a and 16b and a side wall surface 17a. The first track surface 16a is inclined with respect to the X-Y plane and is provided on the side of the lower end surface 12b of the rail. The first track surface 16b is inclined with respect to the X-Y plane and is provided on the side of the upper end surface 12a of the rail. The side wall surface 17a is provided in conjunction with each of the first track surfaces 16a and 16b. The first track groove 15b is also composed of a pair of first track surfaces 16c and 16d and a side wall surface 17b, similar to the first track groove 15a. Such a linear motion guide unit 10a is used in machine tools, assembly equipment, conveying machines, etc., and is particularly suitable for use in high-speed moving parts of equipment including these. For example, a rail width of 8 mm is preferably used for the rail 11a. Multiple through holes 20a and 20b are provided in the rail 11a, extending in the Z direction from the upper end surface 12a to the lower end surface 12b. In this embodiment, two through holes 20a and 20b are provided, and are shown by dashed lines in Figure 3 for simplicity. The multiple through holes 20a and 20b are spaced apart in the Y direction. The through holes 20a and 20b are used, for example, to mount the linear motion guide unit 10a.

[0026] Next, the configuration of the slider 31a will be described. The slider 31a is attached to the rail 11a so as to be movable relative to it in the longitudinal direction (Y direction). In this embodiment, the slider 31a is slidably straddled on the rail 11a. The slider 31a is provided with a recessed fitting portion 32a in the Z direction, and the rail 11a is fitted into this fitting portion 32a. In other words, the slider 31a is attached so as to straddle the rail 11a and is movable in the Y direction.

[0027] The slider 31a includes a casing 33a, circulation modules 34a, 34b, 34c, 34d, roller holding members 35a, 35b, end caps 36a, 36b, and end seals 37a, 37b. The casing 33a includes a pair of sleeve portions 38a, 38b spaced apart in the X direction, and a connecting portion 39a connecting the sleeve portions 38a, 38b. The circulation modules 34a, 34b, 34c, 34d are used in the linear motion guide unit 10a to circulate the rollers 21a, 21b, 21c, 21d. The circulation modules 34a, 34b are provided in pairs on one sleeve portion 38a, and the circulation modules 34c, 34d are provided in pairs on the other sleeve portion 38b. The circulation modules 34a, 34b, 34c, and 34d are each attached to the casing 33a. The casing 33a is provided with a plurality of recesses 40a that are recessed in the Z direction in the shape of a circular hole. The roller holding members 35a and 35b are each provided for the respective sleeve portions 38a and 38b. The roller holding member 35a is attached to the circulation modules 34a and 34b. The roller holding member 35b is attached to the circulation modules 34c and 34d. The roller holding member 35a holds the rollers 21a and 21b in the casing 33a. The roller holding member 35b holds the rollers 21c and 21d in the casing 33a. A pair of end caps 36a and 36b are provided and are attached to both ends of the casing 33a in the longitudinal direction (Y direction (first direction)). The end caps 36a and 36b are each provided with mounting through-holes 26a and 26b that penetrate in the Y direction. There are two end cap through-holes 26a and 26b, spaced apart in the X direction. A pair of end seals 37a and 37b are provided and attached to both ends of the end caps 36a and 36b in the longitudinal direction. The end seals 37a and 37b are each provided with mounting through-holes 27a and 27b that penetrate in the Y direction. Similar to the end cap through-holes 26a and 26b, there are two end seal through-holes 27a and 27b, spaced apart in the X direction.Furthermore, end seals 37a and 37b are provided with end seal lubrication holes 28a and 28b, respectively, that penetrate through in the Y direction. The specific configurations of the circulation modules 34a, 34b, 34c, and 34d, and the roller holding members 35a and 35b will be described in detail later.

[0028] Figure 9 is a schematic front view of the casing 33a. Figure 10 is an enlarged view showing a part of the casing 33a shown in Figure 9. Figure 10 is an enlarged view including the part indicated by region R2 in Figure 9. Referring together to Figures 9 and 10, the casing 33a includes second raceway surfaces 42a, 42b, 42c, and 42d that are opposite to the first raceway surfaces 16a, 16b, 16c, and 16d, respectively. The raceway 41a on which the roller 21a rolls is composed of the first raceway surface 16a and the second raceway surface 42a. The raceway 41b on which the roller 21b rolls is composed of the first raceway surface 16b and the second raceway surface 42b. The raceway 41c on which the roller 21c rolls is composed of the first raceway surface 16c and the second raceway surface 42c. The track 41d on which the roller 21d rolls is composed of a first track surface 16d and a second track surface 42d. The casing 33a also includes first guide surfaces 43a, 43b, 43c, 43d that contact the first end surfaces 23a, 23b, 23c, 23d located on one end side of the rollers 21a, 21b, 21c, 21d and guide the rollers 21a, 21b, 21c, 21d. The casing 33a is provided with casing relief grooves 44a, 44b, 44c, 44d between the second track surfaces 42a, 42b, 42c, 42d and the first guide surfaces 43a, 43b, 43c, 43d, respectively. The casing relief grooves 44a, 44b, 44c, 44d are each provided to extend in the Y direction.

[0029] Furthermore, the casing 33a is provided with casing through-holes 46a, 46b, 46c, and 46d through which the first circulation paths 45a, 45b, 45c, and 45d, which run parallel to the track paths 41a, 41b, 41c, and 41d, pass. The casing through-holes 46a, 46b, 46c, and 46d are each round and are provided to penetrate the casing 33a straight in the Y direction. The casing through-holes 46a and 46b are provided at the same position in the X direction and spaced apart in the Z direction in the region where the sleeve portion 38a is located. The casing through-holes 46c and 46d are provided at the same position in the X direction and spaced apart in the Z direction in the region where the sleeve portion 38b is located. The height of the casing through-holes 46a and 46c in the Z direction is the same. The height of the casing through-holes 46b and 46d in the Z direction is the same. Furthermore, the casing 33a is provided with casing bolt holes 47a and 47b spaced apart in the X direction for attaching end caps 36a and 36b and end seals 37a and 37b to the casing 33a, respectively.

[0030] Next, the configurations of circulation modules 34a and 34b will be described. Note that the configurations of circulation modules 34c and 34d are the same as those of circulation modules 34a and 34b, so their descriptions will be omitted. Figure 11 is a schematic perspective view showing the combination of the pair of circulation modules 34a and 34b. In Figure 11, for ease of understanding, the roller holding member 35a and the multiple rollers 21a and 21b are shown together, and the illustration of some members is omitted. Figure 12 is a schematic cross-sectional view showing a part of the pair of circulation modules 34a and 34b shown in Figure 11. Figure 12 is a cross-sectional view when the X-Y plane is cut by a plane tilted at 45 degrees. Figure 13 is a schematic perspective view of the entire circulation module 34a.

[0031] Referring together to Figures 11, 12, and 13, the circulation module 34a includes a circulation box section 51a and a pair of cylindrical sections 52a and 53a. The cylindrical section 52a is hollow and cylindrical, with a portion of the first circulation path 45a provided inside. The cylindrical section 52a includes a first section 54a having an arc-shaped portion when viewed in the longitudinal direction, and a second section 55a having an arc-shaped portion when viewed in the longitudinal direction. The second section 55a and the first section 54a are combined to form a hollow cylindrical section. The cylindrical section 53a is also hollow and cylindrical, similar to the cylindrical section 52a. The cylindrical section 53a has a portion of the first circulation path 45b provided inside. The cylindrical section 53a includes a first section 56a having an arc-shaped portion when viewed in the longitudinal direction, and a second section 57a ​​having an arc-shaped portion when viewed in the longitudinal direction. The first part 56a and the second part 57a are combined to form a hollow cylindrical part. The circulation module 34b, like the circulation module 34a, includes a circulation box part 51b, a cylindrical part 52b composed of a first part 54b and a second part 55b, and a cylindrical part 53b composed of a first part 56b and a second part 57b. The circulation module 34c includes a circulation box part 51c, a cylindrical part 52c composed of a first part 54c and a second part 55c, and a cylindrical part 53c composed of a first part 56c and a second part 57c. The circulation module 34d includes a circulation box part 51d, a cylindrical part 52d composed of a first part 54d and a second part 55d, and a cylindrical part 53d composed of a first part 56d and a second part 57d.

[0032] The circulation module 34a and the circulation module 34b are assembled such that the ends of the cylindrical portions 52a and 53a of the circulation module 34a abut against the ends of the cylindrical portions 52b and 53b of the circulation module 34b. The ends of the cylindrical portions 52a and 53a and the ends of the cylindrical portions 52b and 53b are shaped to fit together. When the circulation module 34a and the circulation module 34b are assembled, the hollow cylindrical portion formed by the cylindrical portion 52a and the hollow cylindrical portion formed by the cylindrical portion 52b are connected to form a first circulation path 45a parallel to the track path 41a. Similarly, when the circulation module 34a and the circulation module 34b are assembled, the hollow cylindrical portion formed by the cylindrical portion 53a and the hollow cylindrical portion formed by the cylindrical portion 53b are connected to form a first circulation path 45b parallel to the track path 41b.

[0033] The circulation box section 51a is provided with second circulation paths 58a and 59a. The second circulation paths 58a and 59a are formed by recessing a part of the circulation box section 51a. The second circulation paths 58a and 59a are provided in an arc shape, folding back in the Y direction. The second circulation path 58a connects the track 41a and the first circulation path 45a. The second circulation path 59a connects the track 41b and the first circulation path 45b. Similarly, the circulation box section 51b is also provided with a second circulation path. During the linear reciprocating motion of the slider 31a, the roller 21a moves in a circulating manner within the track 41a, the second circulation path 58a of the circulation box section 51a, the first circulation path 45a, and the second circulation path of the circulation box section 51b. Similarly, during the linear reciprocating motion of the slider 31a, the roller 21b moves in a circulating manner within the track 41b, the second circulation path 59a of the circulation box section 51a, the first circulation path 45b, and the second circulation path of the circulation box section 51b. That is, circulation modules 34a and 34b are provided with first circulation paths 45a and 45b parallel to the track paths 41a and 41b, respectively, and second circulation paths 58a and 59a connecting the track paths 41a and 41b to the first circulation paths 45a and 45b, respectively. The configuration of circulation modules 34c and 34d is the same as the configuration of circulation modules 34a and 34b described above.

[0034] The end face 61a of the circulation box section 51a in the Y direction (first direction) is provided with a fitting portion 62a that is recessed inward. The fitting portion 62a includes a first groove-shaped portion 63a that is recessed straight in the X direction, and a second groove-shaped portion 64a that is connected to the X-direction end of the first groove-shaped portion 63a and recessed straight in the Z direction. In this embodiment, the fitting portion 62a is composed of the first groove-shaped portion 63a and the second groove-shaped portion 64a. The fitting portion 62a has a T-shaped recess. The circulation box section 51b is also provided with a fitting portion in the same way. The same applies to the circulation modules 34c and 34d.

[0035] The circulation box section 51a included in the circulation module 34a is provided with a first lubrication hole 65a. The first lubrication hole 65a is recessed from the end face 61a. The first lubrication hole 65a leads from the outside to the second circulation passage 58a. Lubrication can be supplied to the second circulation passage 58a from the outside using the first lubrication hole 65a. When no lubrication is being supplied, the opening of the first lubrication hole 65a is closed by a first stopper (sealing ball) 66a. The circulation modules 34b, 34c, and 34d are also provided with a first lubrication hole and a first stopper, similar to the circulation module 34a.

[0036] The circulation module 34a is attached to the casing 33a by fitting the hollow cylindrical portion formed by the cylindrical portion 52a into the casing through hole 46a and the hollow cylindrical portion formed by the cylindrical portion 53a into the casing through hole 46b. Similarly, the circulation module 34b is attached to the casing 33a by fitting the hollow cylindrical portion formed by the cylindrical portion 52b into the casing through hole 46a and the hollow cylindrical portion formed by the cylindrical portion 53b into the casing through hole 46b. For circulation modules 34a and 34b, the circulation box portions 51a and 51b are installed adjacent to each other in the Y direction.

[0037] Next, the configuration of the roller holding member 35a will be described. Figures 14 and 15 are schematic perspective views of the roller holding member 35a, respectively. Figures 14 and 15 show the roller holding member 35a at different angles. Figure 16 is an enlarged view showing a part of the roller holding member 35a shown in Figures 14 and 15.

[0038] Referring together to Figures 14, 15, and 16, the roller holding member 35a is a thin plate-shaped member extending in the Y direction (longitudinal direction (first direction)). The roller holding member 35a is constructed as a single unit. That is, the roller holding member 35a is not constructed by combining multiple members. The material of the roller holding member 35a includes, for example, at least one of polyacetal, polyetheretherketone, brass, and stainless steel. In this embodiment, the material of the roller holding member 35a is polyacetal.

[0039] The roller holding member 35a includes roller holding claws 71a, 71b, second guide surfaces 72a, 72b, and scooping portions 73a, 74a. The roller holding member 35a is provided with a pair of opening windows 75a, 75b, each extending in the longitudinal direction and spaced apart in the Z direction. The roller holding claws 71a, 71b are each composed of one of the inclined wall surfaces of the roller holding member 35a that defines the opening windows 75a, 75b. The roller holding claws 71a hold the roller 21a by contacting a part of the rolling surface 22a of the roller 21a within the track 41a. That is, the roller holding claws 71a prevent the roller 21a, which rolls on the first track surface 16a of the rail 11a and the second track surface 42a of the casing 33a, from falling out of the track 41a within the track 41a. Similarly, the roller retaining claws 71b contact a portion of the rolling surface 22b of the roller 21b within the track 41b to hold the roller 21b. In other words, the roller retaining claws 71b prevent the roller 21b, which rolls on the first track surface 16b of the rail 11a and the second track surface 42b of the casing 33a, from falling out of the track 41b.

[0040] The second guide surfaces 72a and 72b are each composed of one of the inclined wall surfaces of the roller holding member 35a that defines the opening windows 75a and 75b. The second guide surfaces 72a and 72b are each positioned to face the roller holding claws 71a and 71b in the Z direction. The second guide surface 72a contacts the second end surface 24a located on the other end side of the roller 21a to guide the roller 21a. The second guide surface 72b contacts the second end surface 24b located on the other end side of the roller 21b to guide the roller 21b.

[0041] The scooping section 73a is provided in the boundary region of the second circulation path 58a, which is connected to the track path 41a that extends straight in the Y direction. The movement of the roller 21a in the track path 41a is indicated by arrow D1, and the movement of the roller 21a in the second circulation path 58a is indicated by arrow D2. The scooping section 73a scoops up the roller 21a when it has moved straight along the track path 41a in the Y direction and is being carried into the arc-shaped second circulation path 58a. When the roller 21a moves from the track path 41a to the second circulation path 58a, the scooping section 73a contacts the rolling surface 22a of the roller 21a and guides the roller 21a into the second circulation path 58a. Since the roller holding member 35a is integrally formed with such a scooping section 73a, it is easy to finish the surface of the path from the track path 41a to the second circulation path 58a smoothly. The same applies to the other scooping sections 74a. The scooping sections 74a are located in the boundary region of the second circulation path 59a, which is connected to the track path 41b that extends straight in the Y direction. The movement of the roller 21b on the track path 41b is indicated by arrow D3, and the movement of the roller 21b on the second circulation path 59a is indicated by arrow D4. The scooping section 74a scoops up the roller 21b when it has moved straight along the track path 41b in the Y direction and is being carried into the arc-shaped second circulation path 59a. The scooping section 74a contacts the rolling surface 22b of the roller 21b as it moves from the track path 41b to the second circulation path 59a, guiding the roller 21b into the second circulation path 59a. The same configuration applies to the other scooping sections.

[0042] The roller holding member 35a includes hooking portions 76a and 76b. Each of the hooking portions 76a and 76b has a shape that protrudes in a second direction intersecting the first direction, in this embodiment, in the X direction. A pair of hooking portions is provided at both ends in the longitudinal direction of the roller holding member 35a. The hooking portion 76a includes a first protrusion 77a extending in the second direction, the X direction, and a second protrusion 78a extending in a third direction intersecting both the first direction, the Y direction, and the second direction, the X direction, in this embodiment, in the Z direction. The second protrusion 78a extends from the tip of the first protrusion 77a in both the direction indicated by arrow Z and the direction opposite to the direction indicated by arrow Z. The hooking portion 76a is T-shaped when viewed from the Y direction. The hooking portion 76a can be fitted into the fitting portion 62a provided on the circulation module 34a. The hooking portion 76b has a similar configuration.

[0043] Next, an example of assembling the linear motion guide unit 10a with the above configuration will be briefly explained. First, the circulation modules 34a, 34b, 34c, and 34d are each assembled into the casing 33a. Next, the rollers 21a, 21b, 21c, and 21d are assembled into the track paths 41a, 41b, 41c, and 41d. After that, the roller holding members 35a and 35b are fitted into the circulation modules 34a, 34b, 34c, and 34d. In this case, the hook portion 76a and fitting portion 62a, etc., described above are used. After that, a pair of end caps 36a, 36b and a pair of end seals 37a, 37b are placed at both ends in the longitudinal direction of the casing 33a, and the pair of end caps 36a, 36b and the pair of end seals 37a, 37b are attached to the casing 33a using four bolts 25a, 25b, 25c, and 25d. In this case, each circulation module, 34a, 34b, 34c, and 34d, is sandwiched in the longitudinal direction between the casing 33a and a pair of end seals 37a and 37b. Then, the rail 11a is inserted into the fitting portion 32a from the longitudinal direction. The linear motion guide unit 10a is assembled in this way.

[0044] According to the linear guide unit 10a configured as described above, the slider 31a that performs linear reciprocating motion with respect to the rail 11a includes a casing 33a, circulation modules 34a, 34b, 34c, 34d, and roller holding members 35a, 35b. Such a linear guide unit 10a is composed of first circulation paths 45a, 45b, 45c, 45d and second circulation paths 58a, 59a provided in the circulation modules 34a, 34b, 34c, 34d and track paths 41a, 41b, 41c, 41d, and a plurality of rollers 21a, 21b, 21c, 21d circulate through these paths. According to such a configuration, it becomes easy to accurately position the circulation modules 34a, 34b, 34c, 34d with respect to the track paths 41a, 41b, 41c, 41d, and the paths through which the rollers 21a, 21b, 21c, 21d circulate can be accurately formed. Further, since the roller holding member 35a includes roller holding claws 71a, 71b, it becomes easier to stably hold the postures of the rollers 21a, 21b in the track paths 41a, 41b as compared with the case where the roller holding claws 71a, 71b are provided on the rail 11a side. Furthermore, since the roller holding member 35a includes second guide surfaces 72a, 72b, the rollers 21a, 21b can be appropriately guided in the track paths 41a, 41b while suppressing the inclination of the rollers 21a, 21b. Also, the roller holding member 35a includes scooping portions 73a, 74a that come into contact with the rolling surfaces 22a, 22b of the rollers 21a, 21b and guide the rollers 21a, 21b to the second circulation paths 58a, 59a when the rollers move from the track paths 41a, 41b to the second circulation paths 58a, 59a. Moreover, the roller holding member 35a is integrally formed. Then, when the rollers 21a, 21b are moved from the track paths 41a, 41b to the second circulation paths 58a, 59a by the scooping portions 73a, 74a, the rollers 21a, 21b will not get caught on the steps caused by combining a plurality of parts or the chamfers provided at the corners of the parts. Therefore, it is possible to suppress the toppling of the rollers 21a, 21b during the movement of the rollers 21a, 21b and move the rollers 21a, 21b more smoothly. From the above, according to the linear guide unit 10a, the slider 31a can be stably linearly reciprocated.

[0045] Furthermore, with the linear motion guide unit 10a configured as described above, as shown in Figure 7 in particular, since the roller retaining claws 71a are provided on the roller retaining member 35a, it becomes easy to increase the rigidity by making the roller retaining claws 71a thicker in the X direction, and it also becomes easy to align the direction of the center of gravity in the contact area 18a between the first raceway surface 16a and the rolling surface 22a, indicated by arrow G1, with the direction of the center of gravity in the contact area 19a between the second raceway surface 42a and the rolling surface 22a, indicated by arrow G2. Therefore, even when a load is applied to the casing 33a in the direction indicated by arrow F, the load can be properly received. Note that the contact areas 18a and 19a are visualized with thick lines in Figure 7 for ease of understanding.

[0046] In this embodiment, the roller holding member 35a includes hook portions 76a and 76b that protrude in a second direction intersecting the first direction. The circulation modules 34a and 34b are provided with fitting portions 62a that engage with the hook portions 76a and 76b. Therefore, the roller holding member 35a can be accurately and reliably attached to the circulation modules 34a and 34b by utilizing the hook portions 76a and 76b of the roller holding member 35a and the fitting portions 62a of the circulation modules 34a and 34b. Consequently, the circulation paths of the rollers 21a and 21b can be formed with high precision.

[0047] In this embodiment, the hook portion 76a includes a first projection 77a extending in a second direction and a second projection 78a extending in a third direction intersecting both the first and second directions. Therefore, the first projection 77a and the second projection 78a reliably engage with the fitting portion 62a, reducing the risk of the roller holding member 35a attached to the circulation modules 34a and 34b shifting position or detaching from the circulation modules 34a and 34b. Consequently, the roller holding member 35a can be attached to the circulation modules 34a and 34b more reliably.

[0048] In the present embodiment, the engaging portions 76a and 76b are provided in a pair at both ends of the roller holding member 35a in the first direction. The circulation modules 34a and 34b are provided in a pair arranged side by side in the first direction. A fitting portion 62a is provided in each of the pair of circulation modules 34a and 34b. Therefore, the roller holding member 35a can be reliably attached to each of the pair of circulation modules 34a and 34b. Accordingly, more stable holding of the roller holding member 35a can be realized.

[0049] In the present embodiment, the circulation module 34a is provided with the second circulation paths 58a and 59a, and includes a circulation box portion 51a arranged adjacent to the casing 33a in the first direction, and cylindrical portions 52a and 53a that extend from the circulation box portion 51a in the first direction and are provided with the first circulation paths 45a and 45b inside and are arranged in the casing 33a. Therefore, it becomes easy to efficiently manufacture the circulation module 34a having the above configuration including the first circulation paths 45a and 45b and the second circulation paths 58a and 59a. Accordingly, it becomes easy to improve the productivity of the linear guide unit 10a.

[0050] In the present embodiment, a pair of circulation modules 34a and 34b are included. The pair of circulation modules 34a and 34b are arranged side by side in the first direction. The first circulation path 45a is formed by connecting the pair of cylindrical portions 52a and 52b. The first circulation path 45b is formed by connecting the pair of cylindrical portions 53a and 53b. Therefore, a pair of circulation modules 34a and 34b can be arranged on both sides in the longitudinal direction of the casing 33a, and the first circulation paths 45a and 45b and the second circulation paths 58a and 59a can be efficiently formed. Accordingly, the productivity of the linear guide unit 10a can be further improved.

[0051] In the present embodiment, the circulation module 34a is provided with a first grease supply hole 65a leading from the outside to the second circulation paths 58a and 59a. Therefore, grease can be supplied from the outside to the second circulation paths 58a and 59a using the first grease supply hole 65a, and additional grease supply can be efficiently performed. Accordingly, the convenience during additional grease supply can be improved.

[0052] In this embodiment, the linear guide unit 10a is configured in four rows. The first circulation paths 45a and 45b are provided in pairs, spaced apart in the second direction. The first lubrication hole 65a leads from the second circulation paths 58a and 59a to each of the pair of first circulation paths 45a and 45b. Therefore, it becomes easy to lubricate the pair of first circulation paths 45a and 45b of the four-row linear guide unit 10a using the first lubrication hole 65a. Thus, convenience during additional lubrication can be improved in the four-row linear guide unit 10a.

[0053] In this embodiment, the material of the roller holding member 35a may include at least one of polyacetal (POM), polyetheretherketone (PEEK), brass, and stainless steel. Such materials are suitably used as the material for the roller holding member included in the linear motion guide unit 10a.

[0054] In this embodiment, the linear motion guide unit 10a is of the all-roller type. Therefore, it is possible to include as many rollers 21a, 21b, 21c, and 21d as possible. Consequently, it becomes easier to perform smoother linear reciprocating motion of the slider 31a.

[0055] (Embodiment 2) Next, another embodiment, Embodiment 2, will be described. Figure 17 is an exploded perspective view of the slider 31b included in the linear guide unit in Embodiment 2 of this disclosure. Figure 18 is a schematic front view of the casing 33b included in the linear guide unit in Embodiment 2. Figure 19 is a schematic perspective view of the circulation module included in the linear guide unit in Embodiment 2. The linear guide unit in Embodiment 2 has basically the same configuration as in Embodiment 1 and produces the same effects. However, the linear guide unit in Embodiment 2 differs from the linear guide unit 10a shown in Embodiment 1 in that it has only one lubrication hole for additional lubrication from the outside.

[0056] Referring together to Figures 17, 18, and 19, the linear guide unit in Embodiment 2 comprises a rail (not shown), a slider 31b, and a plurality of rollers 21a, 21b, 21c, and 21d. The slider 31b includes a casing 33b, two pairs of circulation modules 34e, 34f, 34g, and 34h, a pair of roller holding members 35a and 35b, a pair of end caps 36c and 36d, and a pair of end seals 37c and 37d.

[0057] The end cap 36c and end seal 37c are each provided with second lubrication holes 81c and 82c that penetrate in the longitudinal direction (first direction) at the center in the X direction. When viewed in the longitudinal direction, the position of the second lubrication hole 81c in the end seal 37c is set to overlap with the position of the second lubrication hole 82c in the end cap 36c. The end cap 36d and end seal 37d are similarly provided with second lubrication holes. In addition, the end seals 37c and 37d are provided with guide grooves 84c through which the supplied lubricating oil flows.

[0058] Guide grooves 83c are provided on the surfaces of the end seals 37c and 37d that face the end caps 36c and 36d, respectively. Guide grooves 84c are also provided on both longitudinal ends of the casing 33b, each leading from the second lubrication hole 81c to the second circulation paths 58a and 59a of the circulation modules 34e, 34f, 34g, and 34h, specifically the second circulation paths 58a and 59a of the circulation modules 34e, 34f, 34g, and 34h. Furthermore, the circulation module 34e is provided with a guide groove 85c that serves as a path for oil to flow to the second circulation path 59a. The same applies to the other circulation modules 34f, 34g, and 34h.

[0059] According to this embodiment, the second circulation path can be lubricated from the outside using the second lubrication holes 81c, 82c and guide grooves 83c, 84c, 85c, enabling efficient additional lubrication. Therefore, convenience during additional lubrication can be improved.

[0060] (Other Embodiments) In the above embodiment, the linear motion guide unit was configured with four rows, but it is not limited to this, and may also have other numbers of rows, for example, a linear motion guide unit with two rows.

[0061] Furthermore, in the above embodiment, the linear motion guide unit is of the all-roller type, but it is not limited to this, and a configuration that includes a retainer between the rollers to maintain the spacing between the rollers is also possible.

[0062] In the above embodiment, the hook portion is T-shaped, but it is not limited to this, and the hook portion may consist only of a first rod-shaped portion protruding in the X direction, or the hook portion may be L-shaped.

[0063] The embodiments disclosed herein should be understood to be illustrative in all respects and not restrictive in any way. The scope of the invention is defined by the claims and all modifications within the meaning and scope of the claims are intended to be equivalent.

[0064] 10a Linear guide unit, 11a Rail, 12a Upper end face of rail, 12b Lower end face of rail, 13a Side surface of first rail, 13b Side surface 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, 18a, 19a Contact area, 20a, 20b Through hole, 21a, 21b, 21c, 21d Roller, 22a, 22b, 22c, 22d Rolling surface, 23a, 23b, 23c, 23d First end face, 24a, 24b, 24c, 24d Second end face, 25a, 25b, 25c, 25d Bolt, 26a, 26b End cap through holes, 27a, 27b End seal through holes, 28a, 28b Lubrication holes, 31a, 31b Slider, 32a Fitting part, 33a, 33b Casing, 34a, 34b, 34c, 34d, 34e, 34f, 34g, 34h Circulation module, 35a, 35b Roller holding member, 36a, 36b, 36c, 36d End cap, 37a, 37b, 37c, 37d End seal, 38a, 38b Sleeve part, 39a Connecting part, 41a, 41b, 41c, 41d Track, 42a, 42b, 42c, 42d Second track surface, 43a, 43b, 43c, 43d First guide surface, 44a, 44b, 44c, 44d Casing relief grooves, 45a, 45b, 45c, 45d First circulation passages, 46a, 46b, 46c, 46d Casing through holes, 47a, 47b Casing bolt holes, 51a, 51b Circulation box section, 52a, 52b, 52c, 52d, 53a, 53b, 53c, 53d Cylindrical section, 54a, 54b, 54c, 54d, 56a, 56b, 56c, 56d First part, 55a, 55b, 55c, 55d, 57a, 57b, 57c, 57d Second part, 58a, 59a Second circulation passage, 61a End face, 62a Fitting section, 63a First grooved section, 64a Second grooved section, 65a First lubrication hole, 66a First stopper, 71a, 71b Roller retaining claws, 72a, 72b Second guide surface, 73a, 74a Scoop part, 75a, 75b Opening window, 76a, 76b Hook part, 77a First projection, 78a Second projection, 81c, 82c Second lubrication hole, 83c, 84c, 85c Guide groove.

Claims

1. A rail having a first raceway surface extending in a first longitudinal direction; a slider attached to the rail so as to be movable relative to the first raceway surface and having a second raceway surface facing the first raceway surface; a plurality of rollers as rolling elements that roll along a track composed of the first raceway surface and the second raceway surface, wherein the slider includes a casing including a first guide surface and the second raceway surface that contact a first end surface located on one end side of the roller to guide the roller; a circulation module attached to the casing, provided with a first circulation path parallel to the trackway and a second circulation path connecting the trackway and the first circulation path; and a roller holding member attached to the circulation module to hold the roller in the casing, wherein the roller holding member includes a roller holding claw that contacts a part of the rolling surface of the roller in the trackway to hold the roller; and a second guide surface that contacts a second end surface located on the other end side of the roller to guide the roller. A linear motion guide unit comprising a scoop portion that contacts the rolling surface of the roller to guide the roller to the second circulation path when the roller moves from the track to the second circulation path, wherein the roller holding member is integrally formed.

2. The linear motion guide unit according to claim 1, wherein the roller holding member includes a hook portion projecting in a second direction intersecting the first direction, and the circulation module is provided with a fitting portion that engages with the hook portion.

3. The linear motion guide unit according to claim 2, wherein the hook portion includes a first projection extending in the second direction and a second projection extending in a third direction intersecting both the first and second directions.

4. The linear motion guide unit according to claim 2 or 3, wherein the hooking portions are provided in pairs at both ends of the roller holding member in the first direction, the circulation modules are provided in pairs side by side in the first direction, and the fitting portion is provided on each of the pair of circulation modules.

5. The linear motion guide unit according to any one of claims 1 to 4, wherein the circulation module includes a circulation box portion provided with the second circulation path and arranged adjacent to the casing in the first direction, and a cylindrical portion extending from the circulation box portion in the first direction, having the first circulation path provided inside, and arranged within the casing.

6. The linear motion guide unit according to claim 5, wherein the circulation module comprises a pair, the pair of circulation modules are arranged side by side in the first direction, and the pair of cylindrical portions are connected to form the first circulation path.

7. The linear guide unit according to any one of claims 1 to 6, wherein the circulation module is provided with a first lubrication hole leading from the outside to the second circulation path.

8. The linear guide unit according to claim 7, wherein the linear guide unit is composed of four rows, the first circulation path is provided in pairs spaced apart in the second direction, and the first lubrication hole extends from the second circulation path to each of the pair of first circulation paths.

9. A linear motion guide unit according to any one of claims 1 to 8, further comprising: an end cap attached to one end of the casing in the first direction; and an end seal attached to one end of the end cap in the first direction, wherein the end cap, the end seal, and the circulation module are provided with a second lubrication hole leading from the outside to the second circulation path.

10. The linear motion guide unit according to any one of claims 1 to 9, wherein the material of the roller holding member includes at least one of polyacetal, polyetheretherketone, brass, and stainless steel.

11. A linear motion guide unit according to any one of claims 1 to 10, wherein it is a total roller type.

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