Linear motion guide unit

Abstract

Summary: A linear motion guidance unit comprises a first raceway element and a second raceway element, and the second raceway element performs a linear motion relative to the first raceway element in a first direction. The linear motion guidance unit includes a plurality of rollers, a cage that holds the plurality of rollers, a pinion, a first rack, and a second rack. The cage includes a roller holding area that holds the plurality of rollers and a pinion holding area that is adjacent to the roller holding area in the first direction and has a pinion receiving section that receives the pinion such that its outer teeth mesh with the second rack teeth. The roller holding area and the pinion holding area are formed as a single piece.The linear motion guide unit includes a pinion cover that is attached to the pinion holding area, so that the pinion is held between the pinion holding area and the pinion cover, and that the outer teeth mesh with the first rack teeth.

Description

Technical field

[0001] The present disclosure relates to a linear motion guidance unit. State of the art

[0002] A linear motion guide device is known that comprises a pinion and a rack which guide a cage that holds rolling elements (see, for example, patent literature 1). Such a linear motion guide device can guide the cage in a suitable manner by means of a rack and pinion, thereby reducing the risk of misalignment of the cage. Reference list of patent specifications

[0003] Patent literature 1: The published Japanese patent application No. 2002-327742 Summary of the invention: Technical problem

[0004] According to the linear motion guide device disclosed in patent literature 1, a pinion holder for holding the pinion has a two-part configuration and holds the pinion by gripping it with the two independent parts. This pinion holder is then attached to the cage. For attachment, a projection formed on the side of the pinion holder is fitted into a dovetail groove formed on the side of the cage. However, in such a configuration, the projection has an extremely narrow width, especially when miniaturization is desired, which increases the risk of the projection breaking during production or assembly. Furthermore, the width of the dovetail groove also becomes small, which complicates assembly. As a result, productivity cannot be improved.

[0005] In light of the above, one of the tasks is to provide a linear motion guidance unit that can improve productivity. Solution to the task

[0006] The linear motion guidance unit according to the present disclosure comprises: a first raceway element extending in a first direction, which is a longitudinal direction, and a second raceway element extending in the first direction and arranged relative to the first raceway element in a second direction, which is orthogonal to the first direction, wherein the second raceway element performs a linear motion relative to the first raceway element in the first direction. The linear motion guidance unit comprises: a plurality of rollers spaced apart in the first direction such that their rolling axes are alternately orthogonal to one another;a cage arranged between the first raceway element and the second raceway element in the second direction to hold the plurality of rollers, the cage having a plurality of pockets spaced apart in the first direction, each pocket receiving the corresponding roller; a pinion with a plurality of external teeth provided on an outer circumferential surface thereof, the pinion being arranged between the first raceway element and the second raceway element in the second direction and rotatably mounted; a first rack attached to an outer circumferential surface of the first raceway element, the first rack having a plurality of first rack teeth meshing with the external teeth;and a second rack attached to an outer circumferential surface of the second raceway element, the second rack having a plurality of second rack teeth meshing with the outer teeth. The cage comprises a roller holding area that holds the plurality of rollers and a pinion holding area arranged adjacent to the roller holding area in the first direction, the pinion holding area having a pinion receiving section that receives the pinion such that the outer teeth mesh with the second rack teeth. The roller holding area and the pinion holding area are formed in one piece. The linear motion guide unit comprises a pinion cover attached to the pinion holding area such that the pinion is held between the pinion holding area and the pinion cover and that the outer teeth mesh with the first rack teeth. Advantageous effects of the invention

[0007] The productivity of the linear motion guidance unit described above can be improved. Brief description of the drawings [ Fig. 1] Fig. Figure 1 is a schematic perspective view of a linear motion guidance unit in embodiment 1 of the present disclosure. [ Fig. 2] Fig. 2 is a schematic top view of the in Fig. 1 illustrated linear motion guidance unit. [ Fig. 3] Fig. 3 is a schematic side view of the in Fig. 1 illustrated linear motion guidance unit. [ Fig. 4] Fig. 4 is a schematic front view of the in Fig. 1 illustrated linear motion guidance unit. [ Fig. 5] Fig. 5 is a schematic cross-sectional view in which the Fig. 2 cross-sections designated VV. [ Fig. 6] Fig. Figure 6 is a schematic perspective view of the linear motion guidance unit 10a, in which a second raceway element, which is described below, has been removed. [ Fig. 7] Fig. Figure 7 is an enlarged schematic perspective view of a section of a cage. [ Fig. 8] Fig. Figure 8 is a schematic cross-sectional view of a section of the in Fig. 7 cages shown. [ Fig. 9] Fig. 9 is a view of a section of the in Fig. 7 cages shown, viewed from the side of a window section of a bag. [ Fig. 10] Fig. Figure 10 is a schematic perspective view illustrating a procedure for constructing a section of the cage. [ Fig. 11] Fig. Figure 11 is a schematic perspective view illustrating the exterior view of a first rack. [ Fig. 12] Fig. Figure 12 is an enlarged, schematic perspective view of a section of the in Fig. 11 illustrated the first rack. [ Fig. 13] Fig. Figure 13 is an enlarged, schematic perspective view of a section of the cage in an exploded view of the linear motion guide unit. [ Fig. 14] Fig. Figure 14 is a schematic top view of a sprocket cover. [ Fig. 15] Fig. Figure 15 is a schematic side view of the sprocket cover. Description of the embodiments [Overview of embodiments]

[0008] The linear motion guidance unit of the present disclosure comprises: a first raceway element extending in a first direction, which is a longitudinal direction, and a second raceway element extending in the first direction and arranged relative to the first raceway element in a second direction, which is orthogonal to the first direction, wherein the second raceway element performs a linear motion relative to the first raceway element in the first direction. The linear motion guidance unit comprises: a plurality of rollers spaced apart in the first direction such that their rolling axes are alternately orthogonal to one another;a cage arranged between the first raceway element and the second raceway element in the second direction to hold the plurality of rollers, the cage having a plurality of pockets spaced apart in the first direction, each pocket receiving the corresponding roller; a pinion with a plurality of external teeth provided on an outer circumferential surface thereof, the pinion being arranged between the first raceway element and the second raceway element in the second direction and rotatably mounted; a first rack attached to an outer circumferential surface of the first raceway element, the first rack having a plurality of first rack teeth meshing with the external teeth;and a second rack attached to an outer circumferential surface of the second raceway element, the second rack having a plurality of second rack teeth meshing with the outer teeth. The cage comprises a roller holding area that holds the plurality of rollers and a pinion holding area arranged adjacent to the roller holding area in the first direction, the pinion holding area having a pinion receiving section that receives the pinion such that the outer teeth mesh with the second rack teeth. The roller holding area and the pinion holding area are formed in one piece. The linear motion guide unit comprises a pinion cover attached to the pinion holding area such that the pinion is held between the pinion holding area and the pinion cover and that the outer teeth mesh with the first rack teeth.

[0009] In a linear motion guidance unit where the second raceway element performs linear motion relative to the first raceway element, a mechanism is required to ensure smooth linear motion. The linear motion guidance unit described above can prevent misalignment of the cage that holds the rollers by using the pinion, first rack, and second rack. Therefore, it is possible to guide the linear motion appropriately. Here, the outer teeth of the pinion are positioned between the first and second raceway elements, and the first and second racks are each attached to the outer circumferential surfaces of the first and second raceway elements, respectively. This configuration allows the pinion to be positioned in a vertical orientation.This allows the contact length between the raceway surfaces of the raceway links and the rollers to be increased, thereby increasing the load-bearing capacity.

[0010] Here, according to the linear motion guide unit of the present disclosure, the cage comprises a roller holding area that retains the rollers and a pinion holding area that is provided with a pinion receiving section. The roller holding area and the pinion holding area are formed in one piece. This eliminates the need to form a projection and a dovetail groove when a mechanism for retaining the pinion is incorporated into the cage. This avoids damage to the projection and eliminates the work of fitting the projection into the dovetail groove, resulting in improved productivity. In particular, higher productivity can be achieved when manufacturing a linear motion guide unit with small dimensions and rollers with a diameter of, for example, less than 4 mm.Since the pinion is held in place by the pinion cover within the cage, the risk of the pinion becoming dislodged or falling out of the cage is significantly reduced. Therefore, using such a linear motion guide unit can improve productivity.

[0011] In the linear motion guide unit described above, the pinion retaining area can be located in the center in the first direction. A pair of roller retaining areas can be located at both ends in the first direction, holding the pinion retaining area between them. Because the pinion retaining area is located in the center in the first direction, i.e., in the longitudinal direction, the cage can be guided in a balanced manner in the longitudinal direction. Furthermore, this prevents the areas containing the roller retaining areas from becoming unbalanced in the longitudinal direction, allowing the first and second raceway elements to bear the load appropriately.

[0012] In the linear motion guide unit described above, the pinion cover can be attached to the pinion retaining area using a snap-fit ​​mechanism. This allows the elastic deformation of the material to be utilized when the pinion cover is attached, thus enabling the pinion to snap into place. This ensures convenient assembly with a simpler configuration, resulting in improved productivity.

[0013] In the linear motion guide unit described above, at least one of the first and second racks can be plate-shaped. This simplifies the shape of at least one of the first and second racks, potentially improving productivity.

[0014] In the linear motion guide unit described above, at least one of the first and second rack teeth can be designed to project in the second direction. This facilitates the meshing of at least one of the first and second rack teeth in the first rack with the outer teeth of the pinion in the second direction. Therefore, the cage can be guided by enabling suitable meshing between the outer teeth of the pinion and the rack teeth, while simultaneously achieving a reduction in size and a simplification of the shape.

[0015] In the linear motion guide unit described above, the holding claw can comprise a pair of side pieces, a plurality of column sections spaced apart from one another in the first direction and connecting the pair of side pieces to form the pocket, and a holding claw which, viewed from the side where a window section of the pocket is open, is continuously connected to a side wall surface of the pair of side pieces and to a side wall surface of the column section and projects toward the window section to prevent the roll from falling out of the pocket. In this way, when a roll is placed in the pocket above the holding claw, which prevents the roll from falling out, the force pressing against the holding claw can be more easily distributed in the first and second directions.Therefore, the mechanical stress on the holding claw when picking up the roll is reduced, which decreases the risk of damage to the holding claw.

[0016] The linear motion guide unit described above can be provided with a pair of retaining claws, one on each of the side panels. This further reduces the mechanical stress on each retaining claw, thereby minimizing the risk of damage to the claws.

[0017] In the linear motion guide unit described above, the holding claw can have a flat surface that is continuous with the side wall surface of the pair of side pieces and the side wall surface of the column section. This allows the holding claw to be designed relatively simply while providing a relatively large gripping area on the roller, significantly reducing the risk of the roller falling out of the pocket.

[0018] In the linear motion guide unit described above, the retaining claw, viewed from the side where the window section of the pocket is open, can have an isosceles triangular shape with equal sides, corresponding to a section extending through the side wall of the side panel and a section extending through the side wall of the column section. This allows the load-bearing capacity to be more easily and evenly distributed between the side panel and column sections when a roller is installed in the pocket. Therefore, productivity can be improved by achieving better integration.

[0019] In the linear motion guide unit described above, the first and second raceway elements can have an identical shape. This allows for the shared use of components, leading to improved productivity.

[0020] Another linear motion guidance unit of the present disclosure comprises: a first raceway element extending in a first direction, which is a longitudinal direction, and a second raceway element extending in the first direction and arranged relative to the first raceway element in a second direction, which is orthogonal to the first direction, wherein the second raceway element performs a linear motion relative to the first raceway element in the first direction. The linear motion guidance unit comprises: a plurality of rollers spaced apart in the first direction such that their rolling axes are alternately orthogonal to one another;a cage arranged between the first raceway element and the second raceway element in the second direction to hold the plurality of rollers, the cage having a plurality of pockets spaced apart in the first direction, each pocket receiving the corresponding roller; a pinion with a plurality of external teeth provided on an outer circumferential surface thereof, the pinion being arranged between the first raceway element and the second raceway element in the second direction and rotatably mounted; a first rack attached to an outer circumferential surface of the first raceway element, the first rack having a plurality of first rack teeth meshing with the external teeth;and a second rack attached to an outer circumferential surface of the second raceway element, the second rack having a plurality of second rack teeth meshing with the outer teeth. The cage comprises a pair of side pieces, a plurality of column sections spaced apart from each other in the first direction and connecting the pair of side pieces to form the pocket, and a retaining claw which, viewed from a side where a window section of the pocket is open, is continuous with a side wall surface of the pair of side pieces and a side wall surface of the column section and projects towards the window section to prevent the roll from falling out of the pocket.

[0021] According to such a linear motion guide unit, when a roll is inserted into the pocket above the holding claw, which prevents the roll from falling out, the force pressing against the holding claw can be more easily distributed in the first direction and the direction perpendicular to it. Therefore, the mechanical stress on the holding claw when gripping the roll is reduced, which decreases the risk of damage to the holding claw. [Specific embodiments]

[0022] Specific embodiments of the linear motion guidance unit of the present disclosure are described below with reference to the drawings. In the drawings referred to below, identical or corresponding parts are identified by the same reference numerals, and their descriptions are not repeated. (Version 1)

[0023] In the present disclosure, one embodiment, embodiment 1, is described first. Fig. Figure 1 is a schematic perspective view of a linear motion guidance unit in embodiment 1 of the present disclosure.

[0024] Fig. 2 is a schematic top view of the in Fig. 1 illustrated linear motion guidance unit. Fig. 2 is a view as it moves towards the in Fig. 1 illustrated arrow II can be seen. Fig. 3 is a schematic side view of the in Fig. 1 illustrated linear motion guidance unit. Fig. 3 is a view that points in the direction of the Fig. 1 illustrated arrow III is seen. Fig. 4 is a schematic front view of the in Fig. 1 illustrated linear motion guidance unit. Fig. 4 is a view that points in the direction of the Fig. 1 illustrated arrow IV is seen. Fig. 5 is a schematic cross-sectional view in which the Fig. 2 cross-sections designated VV. Fig. Figure 6 is a schematic perspective view of the linear motion guide unit 10a, with a second track element, described below, removed. Fig. In Figure 1 and the following figures, the direction indicated by arrow Y is a longitudinal direction, the direction indicated by arrow X is a transverse direction, and the direction indicated by arrow Z is a thickness direction.

[0025] Referring to the Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6 The linear motion guidance unit 10a of embodiment 1 comprises a first raceway element 11a, a second raceway element 12a, a plurality of rollers 13a, a cage 14a, a pinion 15a, a first rack 16a and a second rack 17a. The first raceway element 11a and the second raceway element 12a each have a shape that extends in the first direction (Y-direction), which is the longitudinal direction.

[0026] The first track element 11a and the second track element 12a are identical in shape. That is, the lengths of the first track element 11a in the first direction (X, Y, and Z directions) are equal to the lengths of the second track element 12a in the X, Y, and Z directions. The second track element 12a corresponds to an element created by inverting the first track element 11a in the Z and X directions.

[0027] The second raceway element 12a is arranged relative to the first raceway element 11a in a second direction (X-direction) that is orthogonal to the first direction. The linear motion guidance unit 10a is a linear motion guidance unit in which the second raceway element 12a performs a linear movement relative to the first raceway element 11a in the first direction.

[0028] The first raceway element 11a comprises a first raceway surface 21a and a second raceway surface 22a on which the rollers 13a roll. The first raceway surface 21a and the second raceway surface 22a each have a flat surface extending longitudinally. The first raceway surface 21a is inclined at 45 degrees with respect to both the XY and YZ planes (see in particular Figure 1). Fig. 3 and Fig. 5) The second raceway surface 22a is also inclined at 45 degrees with respect to the XY and YZ planes. The second raceway surface 22a is inclined at 90 degrees with respect to the first raceway surface 21a. A groove-shaped relief section 23a is provided between the first raceway surface 21a and the second raceway surface 22a, extending in the Y direction.

[0029] A surface 24a in the X-direction of the first raceway element 11a, on the side where the first raceway surface 21a and the second raceway surface 22a are provided, lies parallel to the YZ plane and is arranged such that it faces a surface 34a of the second raceway element 12a, which is described below. Each end surface 25a in the longitudinal direction of the first raceway element 11a has a recess 26a, which is formed in the shape of a round hole. The first raceway element 11a has a plurality of round through-holes 27a, which are provided at intervals in the longitudinal direction and penetrate in the thickness direction (Z-direction). In the present embodiment, a total of seven through-holes 27a are provided.The first raceway element 11a has a plurality of recesses 29a provided around areas where the corresponding through holes 27a are located in the thickness direction (Z-direction), the recesses being recessed in the thickness direction by a surface 28a. In the present embodiment, there are a total of seven recesses 29a. Each recess 29a has a wall surface that is semicircular in the thickness direction and is configured to reach another surface 30a in the X-direction. The first raceway element 11a is also provided with a plurality of mounting holes recessed in the thickness direction by the surface 28a, these holes being used for mounting the first rack 16a. In the present embodiment, a total of four mounting holes are provided at intervals in the longitudinal direction.The mounting holes are arranged in such a way as to avoid the recesses 29a.

[0030] The second raceway element 12a has a similar configuration to the first raceway element 11a. This allows for the sharing of components, leading to improved productivity. In particular, the second raceway element 12a comprises a first raceway surface 31a and a second raceway surface 32a on which the rollers 13a roll. The second raceway element 12a is also provided with a relief section 33a, which has a similar configuration to the relief section 23a. A surface 34a in the X-direction of the second raceway element 12a, on the side where the first raceway surface 31a and the second raceway surface 32a are located, runs parallel to the YZ-plane and is oriented such that it faces surface 24a. Each end surface 35a in the longitudinal direction of the second raceway element 12a has a recess 36a, which is formed in the shape of a round hole.The second raceway element 12a has a total of seven round-shaped through-holes 37a, spaced at intervals along the longitudinal direction and penetrating in the thickness direction. The second raceway element 12a has a total of seven recesses 39a, which are provided around areas where the corresponding through-holes 37a are located in the thickness direction, the recesses being set off in the thickness direction from a surface 38a in the thickness direction. Each recess 39a comprises a semicircular wall surface in the thickness direction and is configured to reach another surface 40a in the X direction.

[0031] The configuration of the rollers 13a and the cage 14a will now be described. Each roller 13a has a solid cylindrical shape. The roller 13a has a rolling surface 41a and a pair of end faces 42a. The direction connecting the centers of the pair of end faces 42a is the direction of the rolling axis of the roller 13a. All rollers 13a are identically shaped. The plurality of rollers 13a are spaced apart longitudinally, i.e., in the first direction, such that their rolling axes are alternately orthogonal to each other. In the present embodiment, the linear motion guide unit 10a comprises 22 rollers 13a.

[0032] Cage 14a has a shape that extends in the first direction, i.e., the longitudinal direction. Cage 14a holds the rollers 13a so that they can roll freely. Cage 14a is made of resin. Cage 14a is positioned between the first raceway element 11a and the second raceway element 12a in the first direction (X-direction), the second direction.

[0033] Fig. Figure 7 is an enlarged, schematic perspective view of a section of cage 14a. Fig. 8 is a schematic cross-sectional view of the in Fig. 7 illustrated section of cage 14a. Fig. 8 is a cross-sectional view of the in Fig. 7 section of the cage shown, when cut in a plane that includes the center in the direction of the roll axis of a roller 13a and is orthogonal to the direction of the roll axis of the roller 13a. Fig. 9 is a view of a section of the in Fig. 7 cage 14a shown, seen from the side of a window section 45a of a pocket 44a. Fig. Figure 9 is a view from the direction in which the rolling surface 41a of the roller 13a, which is received in the pocket 44a, is exposed. Fig. Figure 9 is a view from the direction perpendicular to the direction of the rolling axis of roller 13a, which is housed in pocket 44a. Fig. Figure 9 illustrates the outer shape of the roll 13a contained in pocket 44a by a long dashed short line for better understanding.

[0034] Referring to the Fig. 7, Fig. 8 and Fig. 9. The cage 14a has a plurality of pockets 44a, each holding a roll 13a, which are spaced apart longitudinally, i.e., in the first direction. In the present embodiment, there are 22 pockets 44a, corresponding to the number of rolls 13a. Adjacent pockets 44a are arranged such that the directions in which the rolling surfaces 41a of the rolls 13a held therein are exposed are orthogonal to each other. That is, the pockets 44a are designed such that the opening directions of the window sections 45a of the pockets 44a, through which the rolls 13a are inserted, are alternately orthogonal to each other in adjacent pockets 44a.

[0035] The cage 14a comprises a pair of side parts 51a and 52a and a plurality of column sections 53a that connect the pair of side parts 51a and 52a to form the pockets 44a. The side parts 51a and 52a are flat and plate-shaped with through holes 54a in their center. The through holes 54a serve to allow lubricant to flow in and out and to remove sink marks in the resin during casting. The side parts 51a and 52a are arranged at a 90-degree angle in adjacent pockets 44a. The plurality of column sections 53a are spaced apart from one another in the longitudinal direction (Y-direction), the first direction.

[0036] Here, the cage 14a includes retaining claws 55a and 56a, which prevent a roll 13a from falling out of the pocket 44a. The retaining claws 55a and 56a are arranged in pairs on one side panel 51a and on the other side panel 52a. Viewed from the side where a window section 45a of the pocket 44a is open (see in particular...). Fig. 9), the retaining claw 55a is continuously connected to a side wall surface 57a of the side part 51a and a side wall surface 59a of the column section 53a and projects towards the window section 45a. Viewed from the side where one window section 45a of the pocket 44a is open, the retaining claw 56a is continuously connected to a side wall surface 58a of the side part 52a and the side wall surface 59a of the column section 53a and projects towards the window section 45a. The retaining claws 55a and 56a are each conically shaped when viewed from the side where one window section 45a of the pocket 44a is open. The retaining claws 55a and 56a each have flat surfaces 61a and 62a which are continuous with the corresponding side wall surfaces 57a and 58a of the side part pair 51a and 52a and with the column section 53a.Viewed from the side where one window section 45a of the pocket 44a is open, the retaining claws 55a and 56a each have an isosceles triangular shape, with the section extending with the side wall surface 57a, 58a of the side part 51a, 52a and the section extending with the side wall surface 59a of the column section 53a having equal sides. It should be noted that the sections corresponding to the isosceles sides of the triangle of retaining claw 55a are in . Fig. Figure 9 is illustrated by dashed lines. On the side where one window section 45a of the pocket 44a is open, there are no retaining claws on the side longitudinally opposite the column section 53a. On the side where the other window section 46a of the pocket 44a is open, retaining claws 63a and 64a are formed, which are continuous with a side wall surface 59a of the column section 53a, which is opposite the column section 53a on which the retaining claws 55a and 56a are provided, and with the respective side wall surfaces 57a and 58a of the pair of side parts 51a and 52a, and project in the direction of the window section 46a.

[0037] It should be noted that such holding claws 55a and 56a are manufactured, for example, in the following manner. Fig. Figure 10 is a schematic perspective view illustrating a method for manufacturing a section of cage 14a. Referring to Fig. 10. To manufacture such retaining claws 55a and 56a, a device 67a is produced, which is shaped to have flat surfaces 65a and 66a recessed in molds corresponding to the flat surfaces 61a and 62a forming the retaining claws 55a and 56a. A resin is poured into this device 67a, which is positioned in a pocket 44a, to carry out the shaping. As a result, the retaining claws 55a and 56a, provided with the flat surfaces 61a and 62a, are formed in the sections opposite the flat surfaces 65a and 66a. In this case, the flat surfaces 65a and 66a provided on the device 67a can be formed by chamfering the corners, which simplifies the manufacturing process.Furthermore, the retaining claws 55a and 56a can be reliably formed with the shapes described above even when reduced in size, as the resin can easily flow in due to the configuration.

[0038] The configuration of the pinion 15a and the first rack 16a will now be described. With particular reference to the Fig. 5 and Fig. The pinion 15a has a plurality of external teeth 71a provided on its outer circumference. The pinion 15a comprises rotating shafts 72a and 73a. The pinion 15a is held by the cage 14a and is rotatably mounted about the rotating shafts 72a and 73a.

[0039] Fig. Figure 11 is a schematic perspective view illustrating the external view of the first rack 16a. Fig. Figure 12 is an enlarged, schematic perspective view of a section of the in Fig. 11 illustrated the first rack 16a. As can be seen from the Fig. 11 and Fig. As can be seen in Figure 12, the first rack 16a has a plate shape, in particular a flat plate shape. The first rack 16a is formed, for example, by punching a piece of sheet steel along the outer shape of the first rack 16a and by adding through holes and first rack teeth.

[0040] In the present embodiment, the first rack 16a has a plurality of through holes 74a, four in number, which are formed at intervals in the longitudinal direction to penetrate in the thickness direction, i.e., the Z-direction. The through holes 74a serve to fasten the first rack 16a to an outer circumferential surface of the first raceway element 11a by means of bolts 76a, which in the present embodiment is the surface 28a of the first raceway element 11a. The first rack 16a is provided with a plurality of recesses 75a, in the present embodiment three, which are recessed in the X-direction. The three recesses 75a are arranged such that the through holes 27a and the recesses 29a are exposed when the first rack 16a is fastened to the surface 28a of the first raceway element 11a.The formation of these recesses 75a makes it possible to fix the first raceway element 11a in a predetermined position using the through holes 27a, even after the first rack 16a is attached to the surface 28a of the first raceway element 11a.

[0041] The first rack 16a has a plurality of first rack teeth 77a that mesh with the outer teeth 71a of the pinion 15a. The plurality of first rack teeth 77a is comb-shaped. The plurality of first rack teeth 77a are designed such that they project in the second direction, the X-direction. That is, the first rack teeth 77a are designed such that they project from a side face of the first rack 16a in the X-direction. The first rack teeth 77a are designed such that they have a smaller width on the side that meshes with the outer teeth 71a of the pinion 15a in the Z-direction. In the longitudinal direction, groove sections 78a, which adjoin the first rack teeth 77a, are provided such that they are wider on their side, which engages with the outer teeth 71a of the pinion 15a.The sidewall surfaces forming the first rack teeth 77a are tapered in the X direction. First rack teeth 77a with this shape are manufactured, for example, by compression molding or etching. With such first rack teeth 77a, the thickness of the first rack 16a is equal to the height of the first rack teeth 77a, thus reducing the height of the teeth. The first rack 16a can be made of plastic, although for reasons of strength it can also be made of metal, such as a steel plate.

[0042] The second rack 17a has a similar configuration to the first rack 16a, so a description of the latter is omitted. The second rack 17a has two rack teeth 79a. The second rack 17a is attached to and fixed on the second raceway element 12a.

[0043] The configuration of cage 14a is described again here. Fig. Figure 13 is an enlarged, schematic perspective view of a section of cage 14a in a perspective exploded view of the linear motion guide unit 10a. As shown in the illustration... Fig. As shown in Figure 13, the cage 14a comprises roller holding areas 81a and 82a, which hold the rollers 13a, and a pinion holding area 83a, which holds the pinion 15a. In the present embodiment, two roller holding areas, 81a and 82a, are provided. The roller holding areas 81a, 82a, and the pinion holding area 83a are arranged side by side in the longitudinal direction, i.e., in the first direction. The pinion holding area 83a is arranged in the middle in the first direction. The two roller holding areas 81a and 82a are arranged at both ends in the first direction and hold the pinion holding area 83a sandwiched between them. Each of the roller holding areas 81a and 82a is provided with 11 pockets 44a.

[0044] The pinion holding area 83a is provided with a pinion receiving section 84a. The pinion receiving section 84a is set off from a surface 85a in the Z-direction by means of a recess. The pinion receiving section 84a is also provided with pivot shaft receiving sections 86a and 87a, which receive the pivot shafts 72a and 73a. The pinion receiving section 84a extends in the Z-direction, except in the areas where the pivot shaft receiving sections 86a and 87a are provided. This configuration of the pinion receiving section 84a exposes the outer teeth 71a of the received pinion 15a in the Z-direction, so that the exposed outer teeth 71a of the pinion 15a can mesh with the second rack teeth 79a of the second rack 17a.

[0045] The pinion retaining area 83a is also provided with a pair of locating grooves 88a and 89a. The locating grooves 88a and 89a are spaced apart longitudinally to enclose the pinion receiving section 84a between them. The locating grooves 88a and 89a are each located adjacent to the two roller retaining areas 81a and 82a.

[0046] Here, the linear motion guide unit 10a includes a pinion cover 91a. Fig. Figure 14 is a schematic top view of the pinion cover 91a. Fig. Figure 15 is a schematic side view of the pinion cover 91a. The pinion cover 91a is attached to the pinion retaining area 83a (see the Fig. 14 and Fig. 15 together). The pinion cover 91a is made, for example, of a plastic and can be easily elastically deformed. The pinion cover 91a comprises a cavity section 92a, which has a longitudinally extending shape and receives a section of the pinion retaining area 83a therein, an opening 93a that penetrates in the Z-direction, and hook-shaped locating claws 94a and 95a, which are provided longitudinally at both ends of the pinion cover 91a. The pinion cover 91a is attached to the pinion retaining area 83a by elastically deforming the locating claws 94a and 95a and fitting them into the locating grooves 88a and 89a. The locating claws 94a and 95a are attached to the pinion retaining area 83a in the manner of a snap fastener. At this point, a section of the pinion retaining area 83a enters the cavity section 92a, and the pinion 15a is held between the pinion retaining area 83a and the pinion cover 91a.Consequently, the outer teeth 71a of the pinion 15a are exposed in the opening 93a. The exposed outer teeth 71a mesh with the first rack teeth 77a of the first rack 16a.

[0047] According to the linear motion guide unit 10a with the above configuration, misalignment of the cage 14a, which holds the rollers 13a, can be prevented by using the pinion 15a, the first rack 16a, and the second rack 17a. Therefore, it is possible to guide the linear motion appropriately. The outer teeth 71a of the pinion 15a are arranged between the first raceway element 11a and the second raceway element 12a, and the first rack 16a and the second rack 17a are each attached to the outer circumferential surfaces of the first raceway element 11a and the second raceway element 12a, respectively. With this configuration, the pinion 15a can be arranged in a so-called vertical orientation. This increases the contact length between the raceway surfaces of the raceway elements and the rollers 13a, thereby increasing the load-bearing capacity.

[0048] Furthermore, the cage 14a, according to the linear motion guide unit 10a described above, comprises roller holding areas 81a and 82a, which hold the rollers 13a, and a pinion holding area 83a, which is provided with a pinion receiving section 84a. The roller holding areas 81a, 82a, and the pinion holding area 83a are formed in one piece. This eliminates the need to form a projection and a dovetail groove when a mechanism for holding the pinion 15a is incorporated into the cage 14a. This prevents damage to the projection and eliminates the work of fitting the projection into the dovetail groove, resulting in improved productivity. In particular, higher productivity can be achieved when manufacturing a linear motion guide unit 10a with small dimensions and rollers 13a with a diameter of, for example, less than 4 mm.Since the pinion 15a is held in the cage 14a by the pinion cover 91a, the risk of the pinion 15a becoming detached from or falling out of the cage 14a is greatly reduced. Therefore, productivity can be improved with this linear motion guide unit 10a.

[0049] In the present embodiment, the pinion retaining area 83a is arranged in the center in the first direction. The roller retaining areas 81a and 82a are arranged as a pair at the ends in the first direction, holding the pinion retaining area 83a between them. Since the pinion retaining area 83a is arranged in the center of the first direction, i.e., the longitudinal direction, the cage 14a can be guided in a balanced manner in the longitudinal direction. Furthermore, the areas in which the roller retaining areas 81a and 82a are located are prevented from becoming unbalanced in the longitudinal direction, so that the first raceway element 11a and the second raceway element 12a can bear the load appropriately.

[0050] In the present embodiment, the pinion cover 91a is attached to the pinion retaining area 83a by means of a snap-fit ​​connection. This allows the elastic deformation of the material to be utilized when attaching the pinion cover 91a to engage the pinion 15a. Therefore, convenient assembly with a simpler configuration is ensured, leading to improved productivity.

[0051] In the present embodiment, the first rack 16a and the second rack 17a are both plate-shaped. This allows for a simplified shape of both the first rack 16a and the second rack 17a, which can improve productivity.

[0052] In the present embodiment, both the first rack teeth 77a and the second rack teeth 79a are designed to project in the second direction. This facilitates the meshing of both the first rack teeth 77a, which are provided in the first rack 16a, and the second rack teeth 79a, which are provided in the second rack 17a, with the outer teeth 71a of the pinion 15a in the second direction. Therefore, the cage 14a can be guided by enabling suitable meshing between the outer teeth 71a of the pinion 15a and the rack teeth, while simultaneously achieving a reduction in size and a simplification of the shape.

[0053] In the present embodiment, the cage 14a comprises a pair of side parts 51a and 52a, a plurality of column sections 53a spaced apart from each other in the first direction and connecting the pair of side parts 51a and 52a to form the pocket 44a, and retaining claws 55a and 56a which, viewed from the side where the window section 45a of the pocket 44a is open, are continuous with the respective side wall surfaces 57a and 58a of the pair of side parts 51a and 52a and the side wall surface 59a of the column section 53a and project towards the window section 45a to prevent the roll 13a from falling out of the pocket 44a. Therefore, if a roll 13a is received in the pocket 44a via the retaining claws 55a and 56a, which prevent the roll 13a from falling out of the pocket 44a, the force pressing against the retaining claws 55a and 56a can be more easily distributed in the first and second directions. In particular, Fig. 9. When attempting to insert a roller 13a from the side of the window section 45a into the pocket 44a, a force is generated that presses against each of the retaining claws 55a and 56a in the direction indicated by arrow F1. This force F1, however, divides into force F2, indicated in the longitudinal direction (i.e., the first direction), and force F3, indicated in the perpendicular direction. In this case, the side parts 51a and 52a tend to bend, particularly in the direction indicated by force F3, so that they can be deformed with a relatively small force. This reduces the mechanical stress on the retaining claws 55a and 56a when the roller 13a is inserted, thus decreasing the risk of damage to the retaining claws 55a and 56a.

[0054] In the present embodiment, a pair of retaining claws 55a and 56a is provided, one on one side part 51a and the other on the other side part 52a. This further reduces the mechanical stress on the retaining claws 55a and 56a, which can further decrease the risk of damage to the retaining claws 55a and 56a.

[0055] In the present embodiment, the retaining claws 55a and 56a comprise flat surfaces 61a and 62a that are continuous with the respective side wall surfaces 57a and 58a of the pair of side parts 51a and 52a and the side wall surface 59a of the column section 53a. In this way, the retaining claws 55a and 56a can be formed relatively easily, having relatively large areas that grip the roller 13a, thereby significantly reducing the risk of the roller 13a falling out of the pocket 44a.

[0056] In the present embodiment, the retaining claws 55a and 56a, viewed from the side where the window section 45a of the pocket 44a is open, each have an isosceles triangular shape with equal sides, corresponding to a section extending through the side wall surface 57a, 58a of the respective side part 51a, 52a and a section extending through the side wall surface 59a of the column section 53a. Thus, when a roller 13a is installed in the pocket 44a, the load-bearing capacity can be more easily and evenly distributed between the side of the side part 51a, 52a and the side of the column section 53a. Therefore, productivity can be improved by achieving better integration.

[0057] Alternatively, the linear motion guidance unit 10a of the present disclosure comprises a first raceway element 11a extending in a first direction, which is a longitudinal direction, and a second raceway element 12a extending in the first direction and arranged relative to the first raceway element 11a in a second direction, which is orthogonal to the first direction, wherein the second raceway element 12a performs a linear motion relative to the first raceway element 11a in the first direction. The linear motion guidance unit 10a comprises: a plurality of rollers 13a spaced apart in the first direction such that their rolling axes are alternately orthogonal to each other;a cage 14a arranged between the first raceway element 11a and the second raceway element 12a in the second direction to hold the plurality of rollers 13a, the cage having a plurality of pockets 44a spaced apart in the first direction, each pocket receiving the corresponding roller 13a; a pinion 15a having a plurality of external teeth 71a provided on an outer circumference thereof, the pinion being arranged and rotatably mounted between the first raceway element 11a and the second raceway element 12a in the second direction; a first rack 16a attached to an outer circumferential surface of the first raceway element 11a and having a plurality of first rack teeth 77a meshing with the external teeth 71a;and a second rack 17a, which is attached to an outer circumferential surface of the second raceway element 12a and has a plurality of second rack teeth 79a which mesh with the outer teeth 71a. The cage 14a comprises a pair of side parts 51a and 52a, a plurality of column sections 53a arranged separately from one another in the first direction and connecting the pair of side parts 51a and 52a to form the pocket 44a, and a retaining claw 55a, 56a which, viewed from a side where a window section 45a of the pocket 44a is open, is continuous with a side wall surface 57a, 58a of the pair of side parts 51a and 52a and a side wall surface 59a of the column section 53a and projects towards the window section 45a to prevent the roll 13a from falling out of the pocket 44a.

[0058] According to such a linear motion guide unit 10a, when a roller 13a is picked up in the pocket 44a via the retaining jaws 55a and 56a, which prevents the roller 13a from falling out of the pocket 44a, the force pressing against the retaining jaws 55a and 56a can be more easily distributed in the first and second directions. Therefore, the mechanical load on the retaining jaws 55a and 56a is reduced when picking up the roller 13a, which reduces the risk of damage to the retaining jaws 55a and 56a. (other embodiments)

[0059] The isosceles triangular shape chosen in the preceding embodiment is not limited to this; it can also be a triangular shape with three sides of different lengths or a polygonal shape. The wall surface forming the retaining claw can be recessed in a circular arc or project in a circular arc, viewed from the side where the window section of the pocket is open.

[0060] Furthermore, although a pair of retaining claws is provided in the preceding embodiment, a single retaining claw can also be provided, without being limited to this. In this case, an increased projection, compared to a pair of retaining claws, can more reliably prevent the roll from falling out of the pocket.

[0061] While in the preceding embodiment the pinion cover is attached to the pinion retaining area by means of a snap fastener, the pinion cover can also be attached to the pinion retaining area with screws or the like. Alternatively, in the snap-fit ​​design, the locating claws can be provided in the pinion retaining area and the locating grooves in the pinion cover.

[0062] It is to be assumed that the embodiments disclosed herein are in every respect illustrative and not limiting. The scope of the present invention is defined by the terms of the claims and is intended to include all modifications within the scope and meaning that correspond to the terms of the claims. Reference symbol list

[0063] 10a: Linear motion guide unit; 11a: First raceway element; 12a: Second raceway element; 13a: Roller; 14a: Cage; 15a: Pinion; 16a: First rack; 17a: Second rack; 21a, 31a: First raceway surface; 22a, 32a: Second raceway surface; 23a, 33a: Relief section; 24a, 28a, 30a, 34a, 38a, 40a, 85a: End surface; 25a, 35a, 42a: End surface; 26a, 29a, 36a, 39a: Recess; 27a, 37a, 54a, 74a: Through hole; 41a: Rolling surface; 44a: Pocket; 45a, 46a: Window section; 51a, 52a: Side panel; 53a: Column section; 55a, 56a, 63a, 64a: Retaining claw; 57a, 58a, 59a: Side wall surface; 61a, 62a, 65a, 66a: Flat surface; 67a: Device; 71a: Outer tooth; 72a, 73a: Rotating shaft; 75a: Recess; 76a: Bolt; 77a: First rack tooth; 78a: Grooved section; 79a: Second rack tooth; 81a, 82a: Roller retaining area; 83a: Pinion retaining area; 84a: Pinion mounting section; 86a, 87a: Rotating shaft mounting section; 88a, 89a: Dowel claw; 91a: Sprocket cover; 92a: Cavity section; 93a: Opening;and 94a, 95a: Passport claw.; QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2002

[0003] JP 327742

[0003]

Claims

[1] Linear motion guidance unit comprising a first raceway element extending in a first direction which is a longitudinal direction, and a second raceway element extending in the first direction and arranged opposite the first raceway element in a second direction which is a direction orthogonal to the first direction, wherein the second raceway element performs a linear movement relative to the first raceway element in the first direction, comprising the linear motion guidance unit: a multitude of rollers arranged in the first direction such that their rolling axes are alternately orthogonal to each other; a cage arranged between the first raceway element and the second raceway element in the second direction to hold the plurality of rollers, the cage having a plurality of pockets spaced apart in the first direction, each pocket receiving the corresponding roller; a pinion with a plurality of external teeth provided on an outer circumference thereof, wherein the pinion is arranged and rotatably mounted between the first raceway element and the second raceway element in the second direction; a first rack attached to an outer circumferential surface of the first raceway element, the first rack having a plurality of first rack teeth meshing with the outer teeth; and a second rack attached to an outer circumferential surface of the second raceway element, wherein the second rack has a plurality of second rack teeth that mesh with the outer teeth; the cage encompassing: a roll holding area that holds the multitude of rolls, and a pinion holding area which is arranged adjacent to the roller holding area in the first direction, wherein the pinion holding area has a pinion receiving section which receives the pinion such that the outer teeth mesh with the second rack teeth, wherein the roller holding area and the pinion holding area are formed in one piece, the linear motion guide unit comprising a pinion cover which is attached to the pinion holding area in such a way that the pinion is held between the pinion holding area and the pinion cover and that the outer teeth mesh with the first rack teeth. [2] Linear motion guidance unit according to claim 1, wherein the pinion holding area is arranged in a center in the first direction, and a pair of roller holding areas are arranged at both ends in the first direction and hold the pinion holding area in between. [3] Linear motion guide unit according to claim 1 or 2, wherein the pinion cover is attached to the pinion holding area in the manner of a snap fastener. [4] Linear motion guide unit according to claim 1 or 2, wherein at least one of the first rack and the second rack is plate-shaped. [5] Linear motion guide unit according to claim 1 or 2, wherein at least one of the first rack teeth and the second rack teeth is provided such that it projects in the second direction. [6] Linear motion guidance unit according to claim 1 or 2, wherein the cage comprises a pair of side panels, a multitude of column sections, arranged separately from each other in the first direction and connecting the pair of side parts to form the pocket, and a retaining claw which, viewed from a side where a window section of the pocket is open, is continuously connected to a side wall surface of the pair of side parts and to a side wall surface of the column section and projects towards the window section to prevent the roll from falling out of the pocket. [7] Linear motion guidance unit according to claim 6, wherein a pair of retaining claws is provided, one on each of the side parts. [8] Linear motion guide unit according to claim 6, wherein the retaining claw has a flat surface which is continuous with the side wall surface of the pair of side parts and the side wall surface of the column section. [9] Linear motion guide unit according to claim 6, wherein the retaining claw, viewed from the side where the window section of the pocket is open, has an isosceles triangular shape with equal sides corresponding to a section extending through the side wall surface of the side part and a section extending through the side wall surface of the column section. [10] Linear motion guidance unit according to claim 1 or 2, wherein the first raceway element and the second raceway element have an identical shape. [11] Linear motion guidance unit comprising a first raceway element extending in a first direction, which is a longitudinal direction, and a second raceway element extending in the first direction and arranged opposite the first raceway element in a second direction, which is a direction orthogonal to the first direction, wherein the second raceway element performs a linear motion relative to the first raceway element in the first direction, the linear motion guidance unit comprising: a multitude of rollers arranged in the first direction such that their rolling axes are alternately orthogonal to each other; a cage arranged between the first raceway element and the second raceway element in the second direction to hold the plurality of rollers, the cage having a plurality of pockets spaced apart in the first direction, each pocket receiving the corresponding roller; a pinion with a plurality of external teeth provided on an outer circumference thereof, wherein the pinion is arranged and rotatably mounted between the first raceway element and the second raceway element in the second direction; a first rack attached to an outer circumferential surface of the first raceway element, the first rack having a plurality of first rack teeth meshing with the outer teeth; and a second rack attached to an outer circumferential surface of the second raceway element, wherein the second rack has a plurality of second rack teeth that mesh with the outer teeth; the cage encompassing: a pair of side panels, a multitude of column sections, arranged separately from each other in the first direction and connecting the pair of side parts to form the pocket, and a retaining claw which, viewed from a side where a window section of the pocket is open, is continuously connected to a side wall surface of the pair of side parts and to a side wall surface of the column section and projects towards the window section to prevent the roll from falling out of the pocket.

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