Mounting structure for eccentric wheel guide, motion guide device, and eccentric wheel guide

Abstract

To suppress the indentation of the seating surface of the mating member to which the eccentric wheel guide is attached, even when large external forces such as centrifugal force are applied. [Solution] The mounting structure for the eccentric wheel guide comprises a carriage plate 22 and a second wheel guide 21B (eccentric wheel guide) attached to the carriage plate 22. The second wheel guide 21B comprises a second wheel 30B, a second wheel shaft 31B that rotatably supports the second wheel 30B, and an eccentric shaft 32B that is eccentric with respect to the central axis O2 of the second wheel shaft 31B and fixed to the carriage plate 22 via a nut 25. The second wheel shaft 31B has a seating surface 36 on which the eccentric shaft 32B is erected, and a hard washer 40 having a higher hardness than the carriage plate 22 is sandwiched between the carriage plate 22 and the seating surface 36.

Description

Technical Field

[0001] The present invention relates to an eccentric wheel guide mounting structure, a motion guide device, and an eccentric wheel guide.

Background Art

[0002] Patent Document 1 listed below discloses an article transport device. This article transport device includes a guide rail having a desired length, and a movable element that straddles the guide rail and is movable along the outer peripheral surface thereof. Since the guide members (fixed guide roller, adjustment guide roller) provided on both sides of the movable element move along the guide portions provided on both sides of the guide rail, the moving posture of the movable element is stabilized.

[0003] The fixed guide roller includes a shaft fixed to the body by a mounting screw, and a roller rotatably mounted at the tip of the shaft, and the outer peripheral surface of the roller is in contact with the guide portion. Further, the adjustment guide roller includes a cap fixed to the body by a mounting screw, an eccentric shaft whose axis is eccentric with respect to the axis of the cap, and a roller rotatably mounted at the tip of the eccentric shaft, and the gap between the outer peripheral surface of the roller and the guide portion can be adjusted by rotating the eccentric shaft relative to the cap.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0005] In recent years, there has been a demand for motion guidance devices such as those described above that can guide both straight and curved sections of rails, have no play, and be able to move at high speeds. When the moving element passes through a curved section of rail, a large external force is generated by centrifugal force. In such cases, when conventional wheel-type guides (the fixed guide roller and the adjustment guide roller described above) are used, the mating member (the body described above) that contacts the guide may not be able to withstand the external force, and there is a risk that the seating surface of the mating member will collapse. In particular, with the adjustment guide roller (eccentric wheel guide), the surface pressure generated on the side where the eccentric axis is closer is large, making the seating surface of the mating member more prone to collapse.

[0006] This invention has been made in view of the above problems, and aims to suppress the indentation of the seating surface of the mating member to which the eccentric wheel guide is attached, even when a large external force such as centrifugal force is applied. [Means for solving the problem]

[0007] To solve the above problems, the mounting structure for the eccentric wheel guide of the present invention comprises a plate and an eccentric wheel guide attached to the plate, wherein the eccentric wheel guide comprises a wheel, a wheel shaft that rotatably supports the wheel, and an eccentric shaft that is eccentric with respect to the central axis of the wheel shaft and fixed to the plate via a nut, wherein the wheel shaft faces the plate and has a seating surface on which the eccentric shaft is erected, and a spacer having a higher hardness than the plate is sandwiched between the plate and the seating surface.

[0008] Furthermore, the motion guide device of the present invention comprises a rail having a curved section and a carriage that can move along the rail, wherein the carriage comprises a first wheel guide that can move along the inside of the curved section on the rail, a second wheel guide that can move along the outside of the curved section on the rail, and a carriage plate to which the first wheel guide and the second wheel guide are attached, wherein the first wheel guide is a concentric wheel guide comprising a first wheel, a first wheel shaft that rotatably supports the first wheel, and a concentric shaft that is provided concentrically with respect to the central axis of the first wheel shaft and fixed to the carriage plate via a nut, wherein the second wheel guide is an eccentric wheel guide comprising a second wheel, a second wheel shaft that rotatably supports the second wheel, and an eccentric shaft that is eccentric with respect to the central axis of the second wheel shaft and fixed to the carriage plate via a nut, wherein the eccentric wheel guide is attached to the carriage plate by the mounting structure for eccentric wheel guides described above.

[0009] Furthermore, the eccentric wheel guide of the present invention comprises a wheel, a wheel shaft that rotatably supports the wheel, and an eccentric shaft that is eccentric with respect to the central axis of the wheel shaft, wherein the wheel shaft has a seating surface on which the eccentric shaft is erected, and the seating surface has a circular seating surface in plan view, a cylindrical first side surface connected to the seating surface, and a hexagonal prism-shaped second side surface connected to the first side surface and with the circular shape of the seating surface as its circumscribed circle. [Effects of the Invention]

[0010] According to the present invention, even when a large external force such as centrifugal force is applied, it is possible to suppress the indentation of the seating surface of the mating member to which the eccentric wheel guide is attached. [Brief explanation of the drawing]

[0011] [Figure 1] This is a plan view showing a motion guidance device according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line II-II, as shown in Figure 1. [Figure 3] This is an exploded perspective view showing the carriage in the first embodiment of the present invention. [Figure 4] This is a perspective view showing the second wheel shaft and eccentric shaft in the first embodiment of the present invention. [Figure 5] This is a plan view showing the second wheel shaft and eccentric shaft in the first embodiment of the present invention. [Figure 6] This is a cross-sectional view showing the main part of the carriage in the second embodiment of the present invention. [Figure 7] This is a perspective view showing the second wheel shaft and eccentric shaft in a second embodiment of the present invention. [Figure 8] This is a plan view showing the second wheel shaft and eccentric shaft in a second embodiment of the present invention. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. The embodiments shown below are provided as examples to help you better understand the spirit of the invention and do not limit the present invention unless otherwise specified. In addition, the drawings used in the following description may be enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not be the same as in reality. Also, in order to make the features of the present invention easier to understand, some parts have been omitted for convenience.

[0013] [First Embodiment] Figure 1 is a plan view showing the motion guidance device 1 in the first embodiment of the present invention. As shown in Figure 1, the motion guide device 1 comprises a rail 10 and a carriage 20 that moves along the rail 10. The rail 10 is formed in an oval shape in plan view and has a pair of parallel straight sections 11 and a pair of curved sections 12 that connect the ends of the pair of straight sections 11. The rail 10 may be circular, elliptical, egg-shaped, etc., as long as it has curved sections 12.

[0014] The carriage 20 includes a plurality of wheel guides 21 that roll on the side surfaces (the inward facing surface 10A and the outward facing surface 10B) of the rail 10, and a carriage plate 22 guided by the plurality of wheel guides 21. An unillustrated conveyance target object can be attached to the carriage plate 22. For convenience of description, the mounting surface of the carriage plate 22 for the conveyance target object is referred to as the upper surface, and the surface on the opposite side (the rail 10 side) is referred to as the lower surface, but the configuration is not limited to that in which the mounting surface of the carriage plate 22 faces upward.

[0015] The carriage plate 22 is provided above the rail 10 so as to straddle the rail 10 in the width direction. A pair of first wheel guides 21A (concentric wheel guides to be described later) are attached to a portion of the carriage plate 22 located further inward in the width direction than the rail 10. Further, a pair of second wheel guides 21B (eccentric wheel guides to be described later) are attached to a portion of the carriage plate 22 located further outward in the width direction than the rail 10.

[0016] The pair of first wheel guides 21A roll on the inward facing surface 10A of the rail 10. The pair of second wheel guides 21B roll on the outward facing surface 10B of the rail 10. The pair of first wheel guides 21A are attached to the carriage plate 22 at a predetermined pitch in the movement direction of the carriage plate 22 (the longitudinal direction of the rail 10). Further, the pair of second wheel guides 21B are attached to the carriage plate 22 in the movement direction of the carriage plate 22 at a pitch wider than the pitch of the pair of first wheel guides 21A.

[0017] Figure 2 is a cross-sectional view taken along line II-II shown in Figure 1. Figure 3 is an exploded perspective view showing the carriage 20 according to the first embodiment of the present invention. As shown in Figure 2, the rail 10 has a substantially rectangular shape in cross-sectional view. A groove portion 13 and a pair of rolling surfaces 14 are formed on the side surfaces (the inward facing surface 10A and the outward facing surface 10B) of the rail 10.

[0018] The groove portion 13 is formed along the longitudinal direction of the rail 10 at the central portion in the thickness direction (vertical direction) of the rail 10. In addition, the pair of transfer surfaces 14 are formed vertically so as to sandwich the groove portion 13. The pair of transfer surfaces 14 have an inclined shape that separates in the vertical direction as they move away from the groove portion 13 outward in the width direction (left-right direction). That is, on the side surfaces (the inward surface 10A and the outward surface 10B) of the rail 10, a recessed portion having an isosceles trapezoidal shape in which the internal angles of the left and right legs (the pair of transfer surfaces 14) with respect to the base (the groove portion 13) are equal to each other is formed.

[0019] As shown in FIG. 2 and FIG. 3, a plurality of counterbores 23 are formed on the upper surface of the carriage plate 22. The counterbores 23 are formed corresponding to the number and the mounting positions of the wheel guides 21. As shown in FIG. 2, mounting holes 24 for the wheel guides 21 are formed on the bottom surface of the counterbores 23. The mounting holes 24 are formed to penetrate from the bottom surface of the counterbores 23 to the lower surface of the carriage plate 22. The lower surface of the carriage plate 22 is a seating surface that receives surface pressure from the wheel guides 21.

[0020] The mounting shaft 32 of the wheel guide 21 is inserted through the mounting hole 24. A thread is formed on the outer peripheral surface of the mounting shaft 32. The wheel guide 21 is attached to the carriage plate 22 by screwing a nut 25 onto the mounting shaft 32 inside the counterbore 23. A washer 26 is sandwiched between the nut 25 and the bottom surface of the counterbore 23. The washer 26 is formed in a ring shape and arranged around the mounting shaft 32.

[0021] The wheel guide 21 comprises a wheel 30, a wheel shaft 31 that rotatably supports the wheel 30, and a mounting shaft 32 connected to the wheel shaft 31 and fixed to the carriage plate 22 via a nut 25. The wheel shaft 31 and the mounting shaft 32 are molded as a single unit. The wheel 30 rolls along a pair of transfer surfaces 14 of the rail 10. Multiple rolling elements 33 are arranged between the wheel 30 and the wheel shaft 31.

[0022] The rolling elements 33 are, for example, balls, and are arranged in two rows, upper and lower, in the annular gap between the wheel 30 and the wheel shaft 31. The rolling elements 33 may also be cylindrical rollers or other types of rolling elements. The rolling elements 33 are rotatably held by a retainer 34. The retainer 34 is a strip-shaped member positioned in the annular gap between the wheel 30 and the wheel shaft 31, and has multiple holes that maintain the spacing of the rolling elements 33. The retainer 34 moves together with the rolling elements 33 in the annular gap between the wheel 30 and the wheel shaft 31. The annular gap between the wheel 30 and the wheel shaft 31 is covered by a dust cover 35.

[0023] The carriage 20 includes a wheel guide 21, which is a first wheel guide 21A that can travel on the inside of the curved section 12 (the inward-facing surface 10A of the rail 10) on the rail 10, and a second wheel guide 21B that can travel on the outside of the curved section 12 (the outward-facing surface 10B of the rail 10). The first wheel guide 21A is a concentric wheel guide that includes a first wheel 30A, a first wheel shaft 31A that rotatably supports the first wheel 30A, and a concentric shaft 32A that is provided concentrically with the central axis O1 of the first wheel shaft 31A and fixed to the carriage plate 22 via a nut 25.

[0024] The second wheel guide 21B is an eccentric wheel guide comprising a second wheel 30B, a second wheel shaft 31B that rotatably supports the second wheel 30B, and an eccentric shaft 32B that is eccentric with respect to the central axis O2 of the second wheel shaft 31B and fixed to the carriage plate 22 via a nut 25. In other words, the central axis O3 of the eccentric shaft 32B is eccentric with respect to the central axis O2 of the second wheel shaft 31B. The second wheel guide 21B can adjust the gap between the second wheel 30B and the rail 10 by rotating the eccentric shaft 32B around the central axis O3 with respect to the carriage plate 22 and fixing it at a predetermined angle. This suppresses rattling of the carriage 20 relative to the rail 10.

[0025] Figure 4 is a perspective view showing the second wheel shaft 31B and eccentric shaft 32B in the first embodiment of the present invention. Figure 5 is a plan view showing the second wheel shaft 31B and eccentric shaft 32B in the first embodiment of the present invention. As shown in Figure 4, the second wheel shaft 31B faces the carriage plate 22 and has a seating surface 36 on which the eccentric shaft 32B is erected, and a pair of rolling element running surfaces 37 provided below the seating surface 36. The rolling element running surfaces 37 are semicircular grooves in cross-sectional view along the central axis O2, on which the rolling elements 33 (see Figure 2) roll.

[0026] The seat portion 36 faces the carriage plate 22 and has a hexagonal seat surface 36a in plan view and a hexagonal prism-shaped side portion 36b connected to the seat surface 36a. The side portion 36b has six main surfaces 36b1 and six connecting surfaces 36b2. The nut 25 can be tightened by gripping and fixing two parallel surfaces of the six main surfaces 36b1 with a wrench or the like. The connecting surfaces 36b2 connect adjacent main surfaces 36b1 in the circumferential direction around the central axis O2. The connecting surfaces 36b2 may be flat, curved, or absent. In other words, the side portion 36b only needs to have at least six main surfaces 36b1.

[0027] Returning to Figure 2, a hard washer 40 (spacer) is sandwiched between the carriage plate 22 and the seating surface 36. The hard washer 40 is made of a material harder than the carriage plate 22. The carriage plate 22 is made of, for example, aluminum. The hard washer 40 is made of, for example, hardened carbon steel. The seating surface 36 (wheel shaft 31) is made of, for example, hardened carbon steel, the same material as the hard washer 40.

[0028] The hard washer 40 has a Rockwell hardness of 30 [HRC] or higher. More preferably, the hard washer 40 has a Rockwell hardness of 45 [HRC] or higher. The hard washer 40 is not limited to hardened carbon steel as long as it has a Rockwell hardness of 30 [HRC] or higher. Alternatively, a plate material (spacer) having a higher hardness than the carriage plate 22 (a Rockwell hardness of 30 [HRC] or higher) may be inserted between the carriage plate 22 and the seating surface 36.

[0029] As shown in Figure 5, the hard washer 40 is formed to be larger than the seating surface 36 in a plan view. The shape in a plan view refers to the shape viewed from the axial direction in which the central axis O3 extends. Incidentally, the seating surface 36 of the second wheel shaft 31B has a smaller area on the side where the eccentric shaft 32B is located. Specifically, the seating surface 36a is symmetrical with respect to the first reference line L1 that intersects the central axis O3, but not with respect to the second reference line L2 that intersects the central axis O3.

[0030] The first reference line L1 is a straight line in a plan view that connects the central axis O3 of the eccentric shaft 32B and the central axis O2 (not shown in Figure 5) of the second wheel shaft 31B. The second reference line L2 is a straight line in a plan view that is perpendicular to the first reference line L1 at the central axis O3 of the eccentric shaft 32B. With respect to the second reference line L2, the area S2 of the seat surface 36a is smaller on the right side of the paper (the side closer to the eccentric shaft 32B) than the area S1 on the left side of the paper.

[0031] Next, the operation of the mounting structure of the eccentric wheel guide (second wheel guide 21B) with the above configuration will be explained.

[0032] As shown in Figure 1, when the carriage 20 moves along the curved section 12 of the rail 10, centrifugal force acts on the carriage 20. As a result, an external force acts on the first wheel guide 21A, which is located inside the carriage 20, in a direction that presses it against the rail 10. As shown in Figure 2, the first wheel guide 21A has a concentric shaft 32A that is concentric with the first wheel shaft 31A, and therefore has high strength. Thus, the first wheel guide 21A can sufficiently withstand the external force acting in a direction that presses it against the rail 10.

[0033] On the other hand, when the carriage 20 moves along the curved section 12 of the rail 10, an external force acts on the second wheel guide 21B, which is located on the outside of the carriage 20, causing it to move away from the rail 10. As shown in Figure 2, the second wheel guide 21B has an eccentric shaft 32B that is eccentric with respect to the second wheel shaft 31B. By rotating the eccentric shaft 32B in advance and fixing it with a nut 25, preload can be applied from the second wheel 30B to the rail 10. As a result, even when moving along the curved section 12, the second wheel 30B will not move away from the rail 10, and rattling of the carriage 20 can be suppressed.

[0034] Incidentally, the second wheel guide 21B has a small surface area on the side where the eccentric shaft 32B is positioned. Therefore, when an external force acting on the second wheel guide 21B tries to move it away from the rail 10, the surface pressure generated on the side where the eccentric shaft 32B is positioned increases, making the lower surface (seat surface) of the carriage 20 (mating member), which is relatively softer than the second wheel shaft 31B, more prone to indentation. Here, a hard washer 40 with a Rockwell hardness of 30 [HRC] or higher is sandwiched between the carriage plate 22 and the seat surface 36. The hard washer 40 has the same hardness as the seat surface 36 and is harder than the carriage plate 22, thus suppressing indentation of the lower surface of the carriage 20.

[0035] As described above, the mounting structure of the eccentric wheel guide of this embodiment comprises a carriage plate 22 (plate) and a second wheel guide 21B (eccentric wheel guide) attached to the carriage plate 22. The second wheel guide 21B comprises a second wheel 30B (wheel), a second wheel shaft 31B (wheel shaft) that rotatably supports the second wheel 30B, and an eccentric shaft 32B that is eccentric with respect to the central axis O2 of the second wheel shaft 31B and fixed to the carriage plate 22 via a nut 25. The second wheel shaft 31B has a seating surface 36 that faces the carriage plate 22 and on which the eccentric shaft 32B is erected. A hard washer 40 (spacer) having a higher hardness than the carriage plate 22 is sandwiched between the carriage plate 22 and the seating surface 36. This configuration makes it possible to suppress the indentation of the lower surface of the carriage 20.

[0036] Furthermore, in this embodiment, the hard washer 40 is larger than the seating surface 36 in a plan view. With this configuration, the hard washer 40 has a larger contact area with the carriage 20 than the seating surface 36, which reduces the surface pressure the carriage 20 receives from the hard washer 40 and suppresses indentation of the lower surface of the carriage 20.

[0037] Furthermore, in this embodiment, the seating surface 36 faces the carriage plate 22 and has a hexagonal seating surface 36a in plan view and a hexagonal prism-shaped side portion 36b connected to the seating surface 36a. With this configuration, the nut 25 can be tightened more easily by gripping and fixing the side portion 36b with a wrench or the like.

[0038] Furthermore, the motion guide device 1 of this embodiment comprises a rail 10 having a curved section 12, and a carriage 20 that can move along the rail 10. The carriage 20 comprises a first wheel guide 21A that can move along the inside of the curved section 12 on the rail 10, a second wheel guide 21B that can move along the outside of the curved section 12 on the rail 10, and a carriage plate 22 to which the first wheel guide 21A and the second wheel guide 21B are attached. The first wheel guide 21A comprises a first wheel 30A, a first wheel shaft 31A that rotatably supports the first wheel 30A, and a first wheel shaft 3 The first wheel guide is a concentric wheel guide comprising a concentric shaft 32A provided concentrically with the central axis O1 of 1A and fixed to the carriage plate 22 via a nut 25. The second wheel guide 21B is an eccentric wheel guide comprising a second wheel 30B, a second wheel shaft 31B that rotatably supports the second wheel 30B, and an eccentric shaft 32B that is eccentric with respect to the central axis O2 of the second wheel shaft 31B and fixed to the carriage plate 22 via a nut 25. The second wheel guide 21B is attached to the carriage plate 22 by the mounting structure of the eccentric wheel guide described above. With this configuration, a motion guide device 1 can be obtained that can guide both the straight section 11 and the curved section 12 of the rail 10, and that can move at high speed without play.

[0039] [Second Embodiment] Next, a second embodiment of the present invention will be described. In the following description, components identical or equivalent to those in the above-described embodiment will be denoted by the same reference numerals, and their descriptions will be simplified or omitted.

[0040] Figure 6 is a cross-sectional view showing the main part of the carriage 20 in the second embodiment of the present invention. Figure 7 is a perspective view showing the second wheel shaft 31B and eccentric shaft 32B in the second embodiment of the present invention. Figure 8 is a plan view showing the second wheel shaft 31B and eccentric shaft 32B in the second embodiment of the present invention. As shown in these figures, the second wheel guide 21B of the second embodiment includes a seating surface 36 having a round flange portion (second side portion).

[0041] As shown in Figure 7, the seating surface 36 of the second embodiment has, in plan view, a circular seating surface 36a, a cylindrical round flange portion 36c (first side portion) connected to the seating surface 36a, and a hexagonal prism-shaped side portion 36b (second side portion) connected to the round flange portion 36c. The round flange portion 36c is formed with a constant width downward from the outer peripheral edge of the seating surface 36a. The side portion 36b has six main surfaces 36b1 and six connecting surfaces 36b2. The six connecting surfaces 36b2 have a curved shape connected to the circumferential surface of the round flange portion 36c. The six main surfaces 36b1 are formed recessed compared to the circumferential surface of the round flange portion 36c.

[0042] As shown in Figure 8, the seating surface 36 of the second wheel shaft 31B has a smaller area on the side where the eccentric shaft 32B is positioned. Specifically, the seating surface 36a is symmetrical with respect to the first reference line L1 that intersects the central axis O3, but not with respect to the second reference line L2 that intersects the central axis O3. With respect to the second reference line L2, the area S4 of the seating surface 36a is smaller on the right side of the paper (the side where the eccentric shaft 32B is positioned) than on the left side of the paper (the area S3).

[0043] The side portion 36b is formed in the shape of a hexagonal prism with the circular shape of the seating surface 36a as its circumscribed circle. Therefore, compared to the seating surface 36a of the first embodiment, the area S3 on the left side of the paper relative to the second reference line L2 can be made larger than area S1, and the area S4 on the right side of the paper (the side where the eccentric shaft 32B is located) can be made larger than area S2. In this way, the second embodiment can maximize the area by changing the side shape of the second wheel shaft 31B from a hexagonal prism to a cylindrical shape. Furthermore, by keeping the shapes of the seating surface 36a and the round flange portion 36c within the size of the circumscribed circle of the side portion 36b, the overall height, width, and length of the second wheel guide 21B are not changed, so there are virtually no problems in processing and assembly.

[0044] Thus, in the second embodiment, the seating surface 36 faces the carriage plate 22 and has a circular seating surface 36a in plan view, a cylindrical round flange portion 36c connected to the seating surface 36a, and a hexagonal prism-shaped side portion 36b connected to the round flange portion 36c, with the circular shape of the seating surface 36a as its circumscribed circle. With this configuration, the area of ​​the seating surface 36a of the second wheel shaft 31B can be maximized, thereby suppressing indentation of the lower surface of the carriage 20.

[0045] Furthermore, as in the second embodiment, if the area of ​​the seating surface 36a of the second wheel shaft 31B can be maximized, depending on the size of the device, it may be possible to suppress the indentation of the lower surface of the carriage 20 with only the eccentric wheel guide, even without the hard washer 40. For this reason, the following configuration may be adopted.

[0046] In other words, the eccentric wheel guide of this embodiment comprises a second wheel 30B (wheel), a second wheel shaft 31B (wheel shaft) that rotatably supports the second wheel 30B, and an eccentric shaft 32B that is eccentric with respect to the central axis O2 of the second wheel shaft 31B. The second wheel shaft 31B has a seating surface 36 on which the eccentric shaft 32B is erected. The seating surface 36 has a circular seating surface 36a in plan view, a cylindrical round flange portion 36c (first side portion) connected to the seating surface 36a, and a hexagonal prism-shaped side portion 36b (second side portion) connected to the round flange portion 36c and with the circular shape of the seating surface 36a as its circumscribed circle. This configuration also makes it possible to suppress the indentation of the lower surface of the carriage 20.

[0047] Preferred embodiments of the present invention have been described above with reference to the drawings, but the present invention is not limited to the above embodiments. The shapes and combinations of the constituent members shown in the above embodiments are examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention. Furthermore, errors in dimensions and inclinations within the range in which the effects of the present invention are achieved are naturally permissible. [Explanation of symbols]

[0048] 1…Motion guide device, 10…Rail, 10A…Inward-facing surface, 10B…Outward-facing surface, 11…Straight section, 12…Curved section, 13…Groove section, 14…Transfer surface, 20…Carriage, 21…Wheel guide, 21A…First wheel guide, 21B…Second wheel guide, 22…Carriage plate, 24…Mounting hole, 25…Nut, 26…Washer, 30…Wheel, 30A…First wheel, 30B…Second wheel, 31…Wheel shaft, 31A…First wheel shaft, 31B… 32... Mounting shaft, 32A... Concentric shaft, 32B... Eccentric shaft, 33... Rolling element, 34... Retainer, 35... Dust cover, 36... Seat surface, 36a... Seat surface, 36b... Side surface, 36b1... Main surface, 36b2... Connecting surface, 36c... Round flange section, 37... Rolling element rolling surface, 40... Hard washer (spacer), L1... First reference line, L2... Second reference line, O1... Center axis, O2... Center axis, O3... Center axis, S1... Area, S2... Area, S3... Area, S4... Area

Claims

1. A plate and The plate is equipped with an eccentric wheel guide, The aforementioned eccentric wheel guide is Wheels and, A wheel shaft that rotatably supports the aforementioned wheel, The system comprises an eccentric shaft that is eccentric with respect to the central axis of the wheel shaft and fixed to the plate via a nut, The wheel shaft has a seating surface facing the plate and on which the eccentric shaft is erected. A spacer having a higher hardness than the plate is sandwiched between the plate and the seating surface. Mounting structure for eccentric wheel guides.

2. The spacer is larger than the seating surface when viewed from above. Mounting structure for an eccentric wheel guide according to claim 1.

3. The aforementioned seat portion is Opposite to the aforementioned plate, a circular seating surface in plan view, A cylindrical first side portion connected to the seat surface, It has a second side portion which is connected to the first side portion and has a hexagonal prism shape with the circular shape of the seat surface as its circumscribed circle, Mounting structure for an eccentric wheel guide according to claim 1.

4. A rail having a curved section, A carriage that is movable along the rail, The aforementioned carriage is The rail includes a first wheel guide that can travel along the inside of the curved section, The rail includes a second wheel guide that can travel along the outside of the curved section, The device comprises a carriage plate to which the first wheel guide and the second wheel guide are attached, The first wheel guide is a concentric wheel guide comprising a first wheel, a first wheel shaft that rotatably supports the first wheel, and a concentric shaft that is provided concentrically with the central axis of the first wheel shaft and fixed to the carriage plate via a nut. The second wheel guide is an eccentric wheel guide comprising a second wheel, a second wheel shaft that rotatably supports the second wheel, and an eccentric shaft that is eccentric with respect to the central axis of the second wheel shaft and fixed to the carriage plate via a nut. The eccentric wheel guide is attached to the carriage plate by the mounting structure for the eccentric wheel guide described in any one of claims 1 to 3. Movement guidance device.

5. Wheels and, A wheel shaft that rotatably supports the aforementioned wheel, The wheel shaft comprises an eccentric shaft that is eccentric with respect to the central axis of the wheel shaft, The wheel shaft has a seating surface on which the eccentric shaft is erected. The aforementioned seat portion is In plan view, the seat is circular, A cylindrical first side portion connected to the seat surface, It has a second side portion which is connected to the first side portion and has a hexagonal prism shape with the circular shape of the seat surface as its circumscribed circle, Eccentric wheel guide.

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