Linear motion guide unit

Abstract

This linear motion guide unit is provided with a guide rail, a slider, and a plurality of balls as rolling elements. An annular path through which the plurality of rolling bodies circulate is formed by the guide rail and the sliding piece. The loop road comprises a track road composed of a first track groove and a second track groove; a first circulation path formed in the slider and parallel to the track path; and a pair of second circulation paths formed in the slider and connecting the track path and the first circulation path. The slider includes a metal coil spring disposed so as to extend in the longitudinal direction within the first circulation path. The coil spring includes: a first region provided in a portion in the longitudinal direction; and a second region provided so as to be continuous with the first region in the longitudinal direction. The first region is constituted by a compression coil spring. The second region is constituted by a tension coil spring.

Description

Technical Field

[0001] This disclosure relates to a direct-acting guide unit. This application claims priority based on Japanese Application No. 2023-183010, filed on October 25, 2023, and incorporates all the contents of that Japanese application. Background Technology

[0002] A linear rolling guide unit is known, comprising a rolling element and a slider capable of sliding along the long side of a guide rail (see, for example, Patent Document 1). The linear rolling guide unit disclosed in Patent Document 1 includes a return path for returning the rolling element to the track groove and a direction-changing path for changing the direction of the rolling element. In the linear rolling guide unit disclosed in Patent Document 1, a hollow cylindrical sleeve is embedded in the return hole through which the rolling element passes. Furthermore, a slit extending along the long side of the sleeve is provided, allowing for elastic deformation.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 9-72335 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Regarding linear guide units, it is necessary to ensure that the slider slides smoothly and continuously over a long period of time. Therefore, one of the objectives of this invention is to provide a linear guide unit that enables the slider to slide smoothly and continuously over a long period of time.

[0008] means for solving problems

[0009] The direct-acting guide unit disclosed herein comprises: a guide rail having a pair of first track grooves extending parallel to each other along its long side; a slider movably mounted on the guide rail having a pair of second track grooves respectively facing the pair of first track grooves; and a plurality of balls serving as rolling elements. An annular path for circulating the plurality of rolling elements is formed by the guide rail and the slider. The annular path includes: a track path formed by the first track grooves and the second track grooves; a first circulation path formed within the slider and parallel to the track path; and a pair of second circulation paths formed within the slider, connecting the track path and the first circulation path. The slider includes a metal helical spring configured to extend along its long side within the first circulation path. The helical spring includes: a first region disposed in a portion of the long side; and a second region disposed connected to the first region in the long side. The first region is composed of a compression helical spring. The second region is composed of a tension helical spring.

[0010] The effects of the invention

[0011] According to the aforementioned direct-acting guide unit, the slider can slide smoothly and continuously over a long period of time. Attached Figure Description

[0012] Figure 1 This is a schematic perspective view showing the direct-drive guiding unit according to the first embodiment of the present disclosure.

[0013] Figure 2 It means Figure 1 A schematic side view of the direct-acting guide unit shown.

[0014] Figure 3 It means Figure 1 A schematic side view of a portion of the direct-drive guide unit shown.

[0015] Figure 4 It means Figure 1 A schematic top view of a portion of the direct-drive guide unit shown.

[0016] Figure 5 Is Figure 1 The schematic side view of the direct-acting guide unit shown, when the first end cover, which is described later, is removed.

[0017] Figure 6 This is a schematic cross-sectional view showing a portion of the slider, which will be described later.

[0018] Figure 7 yes Figure 6 An enlarged view of the region shown in VII.

[0019] Figure 8 This is a schematic side view of a coil spring.

[0020] Figure 9 This is a schematic perspective view showing the direct-drive guide unit according to the second embodiment of the present disclosure.

[0021] Figure 10 It means Figure 9 A schematic side view of the direct-acting guide unit shown.

[0022] Figure 11 It means Figure 9 A schematic side view of a portion of the direct-drive guide unit shown.

[0023] Figure 12 Is Figure 9 The schematic side view of the direct-acting guide unit shown, when the first end cover, which is one of the end covers, is removed.

[0024] Figure 13 It is a schematic cross-sectional view showing a portion of the slider. Detailed Implementation

[0025] [Summary of Implementation Methods]

[0026] The direct-acting guide unit disclosed herein comprises: a guide rail having a pair of first track grooves extending parallel to each other along its long side; a slider movably mounted on the guide rail having a pair of second track grooves respectively facing the pair of first track grooves; and a plurality of balls serving as rolling elements. An annular path for circulating the plurality of rolling elements is formed by the guide rail and the slider. The annular path includes: a track path formed by the first track grooves and the second track grooves; a first circulation path formed within the slider and parallel to the track path; and a pair of second circulation paths formed within the slider, connecting the track path and the first circulation path. The slider includes a metal helical spring configured to extend along its long side within the first circulation path. The helical spring includes: a first region disposed in a portion of the long side; and a second region disposed connected to the first region in the long side. The first region is composed of a compression helical spring. The second region is composed of a tension helical spring.

[0027] According to the direct-acting guide unit of this disclosure, the helical spring includes: a first region, a portion of which is disposed along its long side and constituted by a compression helical spring; and a second region, which is disposed along its long side and connected to the first region and constituted by a tension helical spring. With this structure, the total length of the helical spring is pre-set to be longer than the length along the long side of the first circulation path. When the helical spring is placed within the first circulation path, it is compressed along the long side by the elastic deformation of the first region, thus accommodating the helical spring within the first circulation path. Consequently, the compression helical spring tends to return to its original shape due to the restoring force, resulting in the helical spring being disposed throughout the entire region along the long side of the first circulation path. Therefore, the possibility of a gap forming between the connection between the first and second circulation paths and the end of the helical spring within the first circulation path can be reduced. As a result, when the ball enters the first circulation path from the second circulation path, the possibility of the end of the helical spring contacting the rolling element can be reduced, and wear on the end of the helical spring can be suppressed. Furthermore, the resistance when the rolling element enters the first circulation path can be reduced. Furthermore, by including such a helical spring, lubricating oil can be supplied to the rolling elements from the gap in the helical spring over the entire area along the long side of the helical spring. Therefore, lubricating oil can be supplied to the rolling elements smoothly. Thus, with such a direct-acting guide unit, the sliding element can slide smoothly and continuously over a long period of time.

[0028] In the aforementioned direct-acting guide unit, the first region can be embedded in the first circulation path. The diameter of the second region can be smaller than the diameter of the first region. Because the first region is embedded in the first circulation path, when the rolling element moves from the second circulation path to the first circulation path, the step difference can be reduced, allowing the rolling element to smoothly enter the first circulation path from the second circulation path. Furthermore, when the rolling element enters the track path, which is a preloaded area, from the second circulation path (which serves as a direction-changing path), the radial gap between the inner wall of the first circulation path and the second region causes the helical spring to elastically deform, absorbing the frictional resistance generated when the rolling element enters the preloaded area. That is, for example, when the slider moves downwards in the vertical direction, and the rolling element is in an interleaved position causing uncertainty in the pressing direction, the radial elastic deformation of the helical spring in the second region with the gap can reduce frictional resistance. Therefore, since there is no need to overcome a large frictional resistance force, the blockage caused by the rolling element getting stuck can be suppressed.

[0029] In the aforementioned direct-acting guide unit, the first region can also be located at one end along the longer side. This arrangement facilitates the formation of the first region, especially when the helical spring is integrally molded. Therefore, increased production efficiency can be achieved.

[0030] In the aforementioned direct-acting guide unit, the helical spring may further include a third region, which is located at the opposite end along the long side and embedded in the first circulation path. The diameter of the second region may be smaller than the diameter of the third region. With this arrangement, since the helical spring is embedded in the first circulation path at both ends along its long side, the step difference can be reduced when the rolling element moves from one of the second circulation paths to the first circulation path, allowing the rolling element to smoothly enter the first circulation path from the second circulation path. Furthermore, since the diameter of the second region is smaller than the diameter of the third region, the radial elastic deformation of the second region can be used to suppress blockage caused by the rolling element getting stuck.

[0031] In the aforementioned direct-acting guide unit, the first region, along its long side, gradually expands in diameter from the portion connected to the second region towards one end. This arrangement suppresses large step differences in the portion of the first region connected to the second region, allowing the rolling elements to move smoothly. Therefore, the sliding element can slide more smoothly.

[0032] In the aforementioned direct-acting guide unit, the inner diameter surface of the first region can be tapered and expanded. By setting it in this way, the formation of step differences in the first region can be suppressed, allowing the first region to gradually expand in the long side direction, thereby enabling the slider to slide smoothly.

[0033] In the aforementioned direct-acting guide unit, the helical spring can also be integrally molded. With this arrangement, the rolling elements can move smoothly inside the helical spring within the first circulation path, and the ease of assembly can be improved.

[0034] In a linear guide unit, the guide rail may include a first guide rail side and a second guide rail side extending parallel to each other along the long side. A sliding member may also straddle the guide rail. A first track groove on one side may also be provided on the first guide rail side. A first track groove on the other side may also be provided on the second guide rail side. Such a linear guide unit is suitable for machine tools, assembly devices, handling machinery, etc.

[0035] In the aforementioned direct-acting guide unit, the track can also be a solid cylindrical or hollow cylindrical splined shaft. The sliding element is hollow cylindrical and can also be disposed on the outer periphery of the track. A pair of first track grooves extending parallel to each other along the long side can be provided on the outer diameter surface of the guide rail. Such a direct-acting guide unit can withstand not only radial loads but also torque. Therefore, it can be effectively utilized when radial loads and torques are generated.

[0036] [Specific examples of implementation methods]

[0037] Next, an example of a specific embodiment of the direct-acting guide unit of this disclosure will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts will be labeled with the same reference numerals and will not be described repeatedly.

[0038] (First Implementation)

[0039] First, a first embodiment, which is an implementation of this disclosure, will be described. Figure 1 This is a schematic perspective view showing the direct-drive guiding unit according to the first embodiment of the present disclosure. Figure 2 It means Figure 1 A schematic side view of the direct-acting guide unit shown. Figure 2 It is observed along the direction indicated by arrow Y. Figure 1 The diagram shows the direct-acting guide unit. Figure 3 It means Figure 1 A schematic side view of a portion of the direct-drive guide unit shown. Figure 3 Observe in the direction indicated by arrow X Figure 1 The diagram shows the direct-acting guide unit. Figure 4 It means Figure 1 A schematic top view of a portion of the direct-drive guide unit shown. Figure 4 It is observed in the direction opposite to that shown by arrow Z. Figure 1 The diagram shows the direct-acting guide unit. Figure 5 Is Figure 1The schematic side view of the direct-acting guide unit shown, when the first end cover, which is described later, is removed. Figure 5 and Figure 2 Similarly, this is the view observed along the direction indicated by arrow Y. Figure 6 This is a schematic cross-sectional view showing a portion of the slider, which will be described later. Figure 7 yes Figure 6 An enlarged view of region VII in the diagram. Figure 6 and Figure 7 In this section, the ball bearing, which will be discussed later, is illustrated in an easy-to-understand manner. Figure 1 In the figures shown below, the X direction represents the short side direction of the width of the linear guide unit, the Y direction represents the long side direction of the linear guide unit, and the Z direction represents the thickness direction (height direction) of the linear guide unit. The X, Y, and Z directions are orthogonal.

[0040] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The first embodiment of the direct-acting guide unit 10a of this disclosure includes a guide rail 11a as a shaft, a slider 21a, and a plurality of balls 20 as rolling elements. The guide rail 11a is configured to extend straight along its long side direction, i.e., the Y direction. The direct-acting guide unit 10a of the first embodiment includes balls 20 as rolling elements, thereby simplifying the structure.

[0041] First, the structure of guide rail 11a will be described. Guide rail 11a includes: an upper end face 12a and a lower end face 12b, spaced apart in the Z direction; a first side face 13a and a second side face 13b, spaced apart in the X direction; and a front end face 14a and a rear end face 14b, spaced apart in the Y direction. That is, guide rail 11a includes a first side face 13a and a second side face 13b extending parallel to each other along the long side direction. Guide rail 11a has a pair of first track grooves 15a and 15b extending parallel to each other along the long side direction. The first track groove 15a is provided on the first side face 13a. The first track groove 15b is provided on the second side face 13b. The first track grooves 15a and 15b are respectively configured to be recessed into the inner side of guide rail 11a to form a semi-circular groove. The first guide rail side 13a and the second guide rail side 13b are respectively provided with recesses 16a and 16b that are further recessed inward in the central region of the first track grooves 15a and 15b in the Z direction. In addition, the linear guide unit 10a with such a guide rail 11a is suitable for machine tools, assembly devices, handling machinery, etc.

[0042] A plurality of through holes 17 are provided on the guide rail 11a, extending from the upper end face 12a to the lower end face 12b of the guide rail along the Z direction. The plurality of through holes 17 are spaced apart in the Y direction. For example, when using the direct-acting guide unit 10a, the through holes 17 can be effectively utilized when the guide rail 11a is installed in a specified position.

[0043] Next, the structure of the slider 21a will be described. The slider 21a is mounted on the guide rail 11a in a way that allows it to move relative to the guide rail 11a. In this embodiment, the slider 21a is slidably mounted across the guide rail 11a. That is, the slider 21a is mounted across the guide rail 11a and can move in the Y direction.

[0044] The slider 21a has a pair of second track grooves 18a and 18b facing the pair of first track grooves 15a and 15b respectively. A ring path 19a for circulating a plurality of balls 20 is formed by the guide rail 11a and the slider 21a. The ring path 19a includes: a track path 22a, formed by the first track grooves 15a and the second track grooves 18a; a first circulation path 23a, formed within the slider 21a and parallel to the track path 22a; and a pair of second circulation paths 24a and 25a, formed within the slider 21a, connecting the track path 22a and the first circulation path 23a. The first circulation path 23a is also called a return path. Additionally, the pair of second circulation paths 24a and 25a are also called direction-changing paths. The track path 22a is a preloaded area with a preload. The first circulation path 23a and the second circulation paths 24a and 25a are unloaded paths without an applied load. The loop track, including the track path formed by the first track groove 15b and the second track groove 18b, also has the same structure. The following structures are also the same.

[0045] The sliding member 21a includes a housing 26a and a pair of end caps 27a and 27b. The housing 26a and the end caps 27a are connected by a plurality of screws 38a, 38b, 38c, and 38d. Similarly, the housing 26a and the end caps 27b are connected by a plurality of screws. Four through holes 37a, 37b, 37c, and 37d are provided on the housing 26a, extending from the upper surface 36a to the lower surface 36b.

[0046] A first circulation path 23a is provided on the housing 26a. The housing 26a also includes second track grooves 18a and 18b. A first end cap 27a is disposed on one side of the housing 26a along its long side. In this embodiment, the first end cap 27a is disposed on the side of the guide rail front end face 14a along its long side. A second circulation path 24a is provided on the first end cap 27a. A second end cap 27b is disposed on the other side of the housing 26a along its long side. In this embodiment, the second end cap 27b is disposed on the side of the guide rail rear end face 14b along its long side. A second circulation path 25a is provided on the second end cap 27b.

[0047] Next, a more detailed description of the structure of the slider 21a will be provided. The slider 21a includes a metal helical spring 30a, which is configured to extend along its long side within the first circulation path 23a. Additionally, the slider 21a includes a metal helical spring 30b, which is configured to extend along its long side within a first annular path comprised of an annular path formed by a first track groove 15b and a second track groove 18b. Since the structure of the helical spring 30b is the same as that of the helical spring 30a, its description is omitted.

[0048] Figure 8 This is a schematic side view of the helical spring 30a. Figure 8 This indicates a state where it is not configured within the first loop path 23a. See also... Figure 8 The helical spring 30a is made of metal. The helical spring 30a is annular, allowing a ball 20 of diameter R1 to pass through it. The length of the helical spring 30a is configured such that, in its free state (i.e., not disposed within the first circulation path 23a), it is slightly longer than the length of the first circulation path 23a. Specifically, referring to… Figure 6 and Figure 8 If the length of the long side of the helical spring 30a is set as length L1, and the length of the long side of the first circulation path 23a is set as length L2, then L1 > L2.

[0049] The helical spring 30a includes a first region 31a, a second region 32a, and a third region 33a. The first region 31a is located at one end 34a along the long side of the helical spring 30a. The third region 33a is located at the other end 34b along the long side. The second region 32a is connected to the first region 31a along the long side. The second region 32a is disposed between the first region 31a and the third region 33a along the long side. In this embodiment, the helical spring 30a is composed of the first region 31a, the second region 32a, and the third region 33a.

[0050] The diameter of the second region 32a is smaller than the diameter of the first region 31a. Figure 7In the diagram, the maximum diameter of the first region 31a is illustrated as diameter D1, and the diameter of the second region 32a is illustrated as diameter D2. In this embodiment, the maximum diameter of the first region 31a is the same as the maximum diameter of the third region 33a. The diameter of the second region 32a is smaller than the diameter of the third region 33a. The second region 32a is disposed between the first region 31a and the third region 33a, and is separated from the inner wall surface 28a of the first circulation paths 23a and 23b by a gap 29a. The radial dimension of the gap 29a is represented by the length D3.

[0051] The first region 31a gradually expands in diameter from the portion connected to the second region 32a towards one end 34a along its long side. That is, the diameter of the first region 31a gradually increases towards one end 34a, with a maximum diameter of D1. The inner diameter surface 35a of the first region 31a is tapered. The angle θ between the tapered inner diameter surface 35a of the first region 31a and the inner diameter surface 35b of the second region 32a is 40 degrees or less. In this embodiment, the angle θ is 30 degrees. The third region 33a gradually expands in diameter from the portion connected to the second region 32a towards the other end 34b along its long side. That is, the diameter of the third region 33a gradually increases towards the other end 34b. Similar to the first region 31a, the inner diameter surface of the third region 33a is tapered. The angle between the tapered inner diameter surface of the third region 33a and the inner diameter surface 35b of the second region 32a is 40 degrees or less. In this embodiment, the angle between the inner diameter surface of the third region 33a and the inner diameter surface 35b of the second region 32a is 30 degrees, the same as that of the first region 31a. In this embodiment, the conical shape of the first region 31a is the same as that of the third region 33a. Furthermore, the length of the long side of both the first region 31a and the third region 33a is less than half the diameter R1 of the ball 20. Specifically, for example, when the diameter R1 of the ball is 5 mm, the length of the long side of both the first region 31a and the third region 33a is 2 mm.

[0052] Here, the first region 31a is composed of a compression helical spring. That is, by compressing the first region 31a along its long side, the total length of the helical spring 30a can be shortened. The second region 32a and the third region 33a are both composed of tension helical springs. Both the second region 32a and the third region 33a are closed springs. The helical spring 30a is integrally formed. The helical spring 30a is manufactured, for example, by preparing a spring material, making the spring material in close contact in the second region 32a and the third region 33a, and in the first region 31a, making the spring material spaced apart to wind around a rod-shaped member, and performing heat treatment, etc.

[0053] As described above, the total length of the helical spring 30a is slightly longer than the length of the long side of the first circulation path 23a. The helical spring 30a is positioned within the first circulation path 23a by compressing the first region 31a. Once the compressed first region 31a is released from compression within the first circulation path 23a, it tends to return to its original shape. As a result, the helical spring 30a becomes positioned within the entire first circulation path 23a. That is, no gaps are generated in the long side direction of the helical spring 30a within the first circulation path 23a.

[0054] According to the aforementioned direct-acting guide unit 10a, the helical spring 30a includes: a first region 31a, located in a portion of the long side direction, which is composed of a compression helical spring; and a second region 32a, connected to the first region 31a along the long side direction, which is composed of a tension helical spring. With this structure, the total length of the helical spring 30a is pre-set to be longer than the length of the first circulation path 23a along its long side. When the helical spring 30a is placed within the first circulation path 23a, it is compressed along the long side direction by the elastic deformation of the first region 31a, thus accommodating the helical spring 30a within the first circulation path 23a. As a result, the compressed helical spring tends to return to its original shape due to the restoring force, allowing the helical spring 30a to be placed throughout the entire long side direction of the first circulation path 23a. Therefore, the possibility of gaps arising between the connection portion of the first circulation path 23a and the second circulation paths 24a, 25a, and the ends 34a, 34b of the helical spring 30a within the first circulation path 23a can be reduced. As a result, when the ball bearing 20 enters the first circulation path 23a from the second circulation path 24a, 25a, the possibility of the ends 34a, 34b of the coil spring 30a contacting the ball bearing 20 can be reduced, and wear on the ends 34a, 34b of the coil spring 30a can be suppressed. Furthermore, the resistance when the ball bearing 20 enters the first circulation path 23a can be reduced. Moreover, by including such a coil spring 30a, lubricating oil can be supplied to the ball bearing 20 from the gap in the coil spring 30a throughout the entire region in the long side direction of the coil spring 30a. Therefore, lubricating oil can be supplied to the ball bearing 20 smoothly. Thus, according to such a direct-acting guide unit 10a, the sliding member 21a can slide smoothly and continuously for a long period.

[0055] Furthermore, in the aforementioned direct-acting guide unit 10a, the helical spring 30a is made of metal. Therefore, even in high-temperature operating environments where it is difficult to use resin components, the aforementioned helical spring 30a can be used to ensure smooth sliding of the slider 21a.

[0056] In this embodiment, the first region 31a is embedded in the first circulation path 23a. The diameter of the second region 32a is smaller than the diameter of the first region 31a. Since the first region 31a is embedded in the first circulation path 23a, when the ball 20 moves from the second circulation path 24a to the first circulation path 23a, the step difference can be reduced, allowing the ball 20 to smoothly enter the first circulation path 23a from the second circulation path 24a. In addition, when the ball 20 enters the preload area, within the first circulation path 23a, the helical spring 30a elastically deforms by utilizing the radial gap 29a provided between the inner wall surface 28a of the first circulation path 23a and the second region 32a, which can absorb the frictional resistance generated when the ball 20 enters the track path 22a, which is a preloaded preload area, from the second circulation paths 24a and 25a, which serve as direction conversion paths. That is, for example, when the slider 21a moves downward in the vertical direction, and the ball 20 is in an interleaved position causing the pressing direction to be uncertain, the radial elastic deformation of the helical spring 30a in the second region 32a with the gap 29a can be used to reduce the frictional resistance. Therefore, since there is no need to overcome a large frictional resistance force, it is possible to suppress the blockage caused by the ball 20 sticking.

[0057] In this embodiment, the first region 31a is provided on one end 34a side in the long side direction. With this structure, especially when the helical spring 30a is integrally formed, the first region 31a is easily formed. Therefore, increased productivity can be achieved.

[0058] In this embodiment, the helical spring 30a includes a third region 33a located at the opposite end 34b in the longitudinal direction and embedded in the first circulation path 23a. The diameter of the second region 32a is smaller than the diameter of the third region 33a. Since the helical spring 30a is embedded in the first circulation path 23a at both ends 34a and 34b in the longitudinal direction, when the balls 20 move from the pair of second circulation paths 24a and 25a to the first circulation path 23a, the step difference can be reduced, allowing the balls 20 to smoothly enter the first circulation path 23a from the second circulation paths 24a and 25a. In addition, since the diameter of the second region 32a is smaller than the diameter of the third region 33a, the radial elastic deformation of the second region 32a can be used to suppress the blockage caused by the sticking of the balls 20.

[0059] In this embodiment, the first region 31a gradually widens in diameter from the portion connected to the second region 32a towards one end 34a in the longitudinal direction. This prevents large step differences from forming in the portion of the first region 31a connected to the second region 32a, allowing the ball bearing 20 to move smoothly. Therefore, the slider 1a can slide more smoothly.

[0060] In this embodiment, the inner diameter surface 35a of the first region 31a is tapered. This suppresses the formation of step differences in the first region 31a and gradually expands the diameter of the first region 31a along its long side, thereby enabling the slider 21a to slide smoothly.

[0061] In this embodiment, the helical spring 30a is integrally formed. As a result, within the first circulation path 23a, the ball 20a can move smoothly inside the helical spring 30a, and the workability during assembly can be improved.

[0062] (Second Implementation)

[0063] Next, a second embodiment, which is another implementation method, will be described. Figure 9 This is a schematic perspective view showing the direct-drive guide unit according to the second embodiment of the present disclosure. Figure 10 It means Figure 9 A schematic side view of the direct-acting guide unit shown. Figure 10 It is observed along the direction indicated by arrow Y. Figure 9 The diagram shows the direct-acting guide unit. Figure 11 It means Figure 9 A schematic side view of a portion of the direct-drive guide unit shown. Figure 11 Viewed from the outer diameter side of the track Figure 9 The diagram shows the direct-acting guide unit. Figure 12 Is Figure 9 A schematic side view of the direct-drive guide unit when the first end cap, which serves as one end cap, is removed. Figure 12 and Figure 10 Similarly, this is the view observed along the direction indicated by arrow Y. Figure 13 This is a schematic cross-sectional view showing a portion of the slider. Figure 13 The ball bearing is shown in the diagram for ease of understanding. The direct-acting guide unit of the second embodiment has essentially the same structure as the first embodiment and achieves the same effect. However, the direct-acting guide unit of the second embodiment differs from the first embodiment in the structure of the guide rail and the sliding member.

[0064] Reference Figure 9 , Figure 10 , Figure 11 , Figure 12 and Figure 13 The second embodiment of the linear guide unit 10b includes a guide rail 11b, a slider 21b, and a plurality of balls 20 serving as rolling elements. The guide rail 11b is configured to extend straight along the Y direction, which is the long side direction. Similar to the first embodiment of the linear guide unit 10a, the structure of the second embodiment of the linear guide unit 10b can also be simplified by including balls 20 as rolling elements.

[0065] The guide rail 11b has a pair of first track grooves 15c and 15d extending parallel to each other along its long side. In this embodiment, the guide rail 11b is a solid cylindrical spline shaft. A pair of first track grooves 15c and 15d extending parallel to each other along their long side are provided on the outer diameter surface 13c of the guide rail 11b. Viewed from the long side, the other first track groove 15d is provided at a position 180 degrees rotated about the center axis 12c of the guide rail 11b, relative to the position where one of the first track grooves 15c is located. The center axis 12c is... Figure 9 The symbol is represented by a single-dot dash. It should be noted that the guide rail 11b can also be a hollow cylinder. That is, the spline shaft can be a solid cylinder or a hollow cylinder.

[0066] Furthermore, the slider 21b is movably mounted on the guide rail 11b. In this embodiment, the slider 21b is a hollow cylindrical shape. Additionally, the slider 21b is disposed on the outer periphery of the guide rail 11b.

[0067] The guide rail 11b has a pair of second track grooves 18c and 18d facing the pair of first track grooves 15c and 15d respectively. A ring-shaped path 19c for circulating a plurality of balls 20 is formed by the guide rail 11b and the slider 21b. The ring-shaped path 19c includes: a track path 22c formed by the first track grooves 15c and 18c; a first circulation path 23c formed within the slider 21b, parallel to the track path 22a; and a pair of second circulation paths 24c and 25c formed within the slider 21b, connecting the track path 22c and the first circulation path 23c. The ring-shaped path including the track path formed by the first track grooves 15d and 18d has the same structure. The following structures are also the same.

[0068] The sliding member 21b includes a housing 26b and a pair of end caps 27c and 27d. A first circulation path 23c is provided on the housing 26b, and the housing 26b also includes second track grooves 18c and 18d. The first end cap 27c is disposed on one side of the housing 26b along its long side. In this embodiment, the first end cap 27c is disposed on the side of the guide rail front end face 14c along its long side. One second circulation path 24c is provided on the first end cap 27c. The second end cap 27d is disposed on the other side of the housing 26b along its long side. In this embodiment, the second end cap 27d is disposed on the side of the guide rail rear end face 14d along its long side. Another second circulation path 25c is provided on the second end cap 27d.

[0069] Next, a more detailed description of the structure of the slider 21b will be provided. The slider 21b includes a metal helical spring 30c arranged within the first circulation path 23c, extending along its long side. Additionally, the slider 21b includes a metal helical spring 30d, which is arranged to extend along its long side within a first annular path comprising a track path formed by a first track groove 15d and a second track groove 18d. Since the structure of the helical spring 30d is the same as that of the helical spring 30c, its description is omitted.

[0070] The helical spring 30c is made of metal. The helical spring 30c is ring-shaped. The helical spring 30c allows a ball 20 with a diameter R1 to pass through its interior. The length of the helical spring 30c is configured such that, in its free state, i.e., when not disposed within the first circulation path 23c, it is slightly longer than the length of the first circulation path 23c.

[0071] The helical spring 30c includes a first region 31c, a second region 32c, and a third region 33c. The first region 31c is located at one end 34c along the long side of the helical spring 30c. The third region 33c is located at the other end 34d along the long side. The first region 31c gradually increases in diameter along its long side from the portion connected to the second region 32c towards one end 34c. The inner diameter surface 35a of the first region 31c is tapered. The third region 33c gradually increases in diameter along its long side from the portion connected to the second region 32c towards the other end 34d. Similarly, the inner diameter surface of the third region 33c is tapered.

[0072] The first region 31c is composed of a compression coil spring. That is, by compressing the first region 31c along its long side, the total length of the coil spring 30c can be shortened. The second region 32c and the third region 33c are both composed of tension coil springs. Both the second region 32c and the third region 33c are closed springs. In addition, since the structure of the coil spring 30c is the same as that of the coil springs 30a and 30b in the first embodiment, its description is omitted.

[0073] In this direct-acting guide unit 10b, since it also includes helical springs 30c and 30d with the aforementioned structure, the sliding member 21b can slide smoothly and continuously for a long period of time. This direct-acting guide unit 10b can withstand not only radial loads but also torque. Therefore, it can be effectively utilized when radial loads and torques are generated.

[0074] (Other implementation methods)

[0075] Furthermore, although in the above embodiment the first region is provided at one end of the helical spring, it is not limited to this. The first region may not be provided at the end; for example, the first region may be provided at the center in the long side direction of the helical spring. Alternatively, a plurality of first regions may be provided in the long side direction. For example, the first region may be provided at both ends in the long side direction of the helical spring instead of the third region.

[0076] Furthermore, although in the above embodiment the first region gradually expands in diameter from the portion connected to the second region toward one end, it is not limited to this; the first region may also be configured such that its diameter increases in stages. Additionally, the inner diameter surface of the first region may not be conical, but rather an arc shape with an increased diameter at the end. The third region is similar. Furthermore, the helical spring may be composed of a plurality of springs of different types; for example, a portion of the first region may be a compression helical spring, and a portion of the second region may be a tension helical spring, formed by arranging a plurality of helical springs along the long side.

[0077] Furthermore, although the number of columns of the track groove or circulation path of the direct-drive guide unit is set to 2 in the above embodiment, it is not limited to this and can also be other numbers, such as 4 columns or 6 columns.

[0078] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limited in any way. The scope of the invention is defined by the claims and is intended to include all modifications in the meaning and scope equivalent to the claims.

[0079] Explanation of reference numerals in the attached figures

[0080] 10a, 10b direct-drive guide units

[0081] 11a, 11b guide rails

[0082] 12a guide rail upper surface

[0083] 12b guide rail lower end face

[0084] 12c Rotation Center Axis

[0085] 13a First guide rail side

[0086] 13b Second Guide Rail Side

[0087] 13c outer diameter surface

[0088] 14a and 14c guide rail front end face

[0089] 14b, 14d guide rail rear end face

[0090] 15a, 15b, 15c, 15d First track slots

[0091] 16a, 16b concave parts

[0092] Through holes 17, 37a, 37b, 37c, and 37d

[0093] Second track slots 18a, 18b, 18c, and 18d

[0094] 19a, 19c ring roads

[0095] 20 ball bearings

[0096] 21a, 21b sliding parts

[0097] 22a and 22c tracks

[0098] 23a, 23b, 23c First loop

[0099] 24a, 24c, 25a, 25c second loop

[0100] 26a, 26b casing

[0101] 27a and 27c end caps (first end caps)

[0102] 27b and 27d end caps (second end caps)

[0103] 28a inner wall surface

[0104] 29a gap

[0105] 30a, 30b, 30c, 30d helical springs

[0106] 31a, 31c First Region

[0107] 32a, 32c Second Region

[0108] 33a, 33c Third Region

[0109] Ends 34a, 34b, 34c, and 34d

[0110] 35a, 35b inner diameter surfaces

[0111] 36a upper surface

[0112] 36b lower surface

[0113] 38a, 38b, 38c, 38d screws

Claims

1. A direct-acting guide unit, wherein, have: The guide rail has a pair of first track grooves that extend parallel to each other along the long side direction; A sliding member, movably mounted on the guide rail, and having a pair of second track grooves respectively facing a pair of first track grooves; and Multiple balls acting as rolling elements, The guide rail and the sliding member form a ring path for the circulation of a plurality of the rolling elements. The loop includes: The track is composed of the first track groove and the second track groove; A first circulation path is formed within the slider and runs parallel to the track path; and A pair of second circulation paths, formed within the slider, connect the track path and the first circulation path. The slider includes a metal helical spring configured to extend along the long side within the first circulation path. The helical spring includes: The first region is located within a portion of the longitudinal side; and The second region is provided, which is connected to the first region along the long side. The first region is composed of a compression helical spring. The second region is formed by a tension helical spring.

2. The direct-acting guide unit according to claim 1, wherein, The first region is embedded in the first loop path. The diameter of the second region is smaller than the diameter of the first region.

3. The direct-acting guide unit according to claim 1 or 2, wherein, The first region is located at one end of the long side.

4. The direct-acting guide unit according to claim 3, wherein, The helical spring further includes a third region, which is located at the end of the spring on the opposite side of the long side and is embedded in the first circulation path. The diameter of the second region is smaller than the diameter of the third region.

5. The direct-acting guide unit according to claim 3, wherein, The first region gradually widens in diameter from the portion connected to the second region toward one end along the long side.

6. The direct-acting guide unit according to claim 5, wherein, The inner diameter of the first region is tapered and expanded.

7. The direct-acting guide unit according to claim 1 or 2, wherein, The helical spring is integrally molded.

8. The direct-acting guide unit according to claim 1 or 2, wherein, The guide rail includes a first guide rail side surface and a second guide rail side surface that extend parallel to each other along the long side direction. The sliding member spans across the guide rail. The first track groove of one side is disposed on the side of the first guide rail. The first track groove of the other party is disposed on the side of the second guide rail.

9. The direct-acting guide unit according to claim 1 or 2, wherein, The guide rail is a solid cylindrical or hollow cylindrical splined shaft. The sliding element is a hollow cylindrical shape and is disposed on the outer periphery of the guide rail. A pair of first track grooves extending parallel to each other along the long side direction are provided on the outer diameter surface of the guide rail.

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