Omnidirectional wheel

Abstract

Omnidirectional wheel (1) whose outer circumferential surface is formed with a plurality of rollers (40, 50) and which rotates about a rotation axis (RL, RL1, RL2) of an axis (10), wherein the omnidirectional wheel (1) comprises: a rotating part (20, 30) that rotates around the axis of rotation (RL, RL1, RL2) of the axis (10); and a plurality of supports (60) arranged in a circumferential direction of the rotating part (20, 30), each of which is mounted on the rotating part (20, 30) to support the plurality of rollers (40, 50) on the rotating part (20, 30), wherein the majority of rollers (40, 50) includes a majority of first rollers (40) and a majority of second rollers (50) with a different outer diameter than the first rollers (40), the first rollers (40) and the second rollers (50) alternate in the circumferential direction, Each of the supports (60) has a first arm element (70) that supports one end side in an axial direction of a corresponding first roller (40) that corresponds to one of the plurality of the first rollers (40), and a second arm element (80) that supports the other end side in the axial direction of the corresponding first roller (40), and a corresponding second roller (50), which corresponds to one of the plurality of second rollers (50), is supported by the first arm element (70) of one of two supports (60) that are adjacent to each other in the circumferential direction, and the second arm element (80) of the other of the two supports (60), wherein one end side in the axial direction of the corresponding first roller (40) is supported by an end side of the first arm element (70), wherein the other end side of the first arm element (70) is mounted on the rotating part (20, 30), and the other end side in the axial direction of the corresponding first roller (40) is supported by an end side of the second arm element (80), the other end side of the second arm element (80) being mounted on the rotating part (20, 30).

Description

[Technical field]

[0001] The present invention relates to an omnidirectional wheel. [State of the art]

[0002] An omnidirectional wheel is known to comprise the following: an axle shaft; a disk-shaped element rotatably mounted on the axle shaft; a plurality of support elements mounted at circumferential intervals on an outer circumferential portion of the disk-shaped element; small-diameter rollers rotatably supported by the respective support elements; and a plurality of large-diameter rollers, each supported by two support elements arranged side by side in the circumferential direction. Such an omnidirectional wheel is disclosed, for example, in JP 3 421 290 B2, as well as in CN 1 08 773 243 A and CN 2 03 957 704 U. In the latter two documents, multi-part rollers are provided that are held along one circumferential direction of the respective omnidirectional wheel by supports, each of which is formed monolithically with integrated arms. [Summary of the invention][Technical problem]

[0003] The outer circumferential surface of an omnidirectional wheel is formed by a plurality of rollers. This makes it difficult to achieve a high degree of compatibility between the rigid support of each roller and the reduction of the omnidirectional wheel's weight. For example, if an omnidirectional wheel is used in a mobility scooter driven by a seated person, each roller may be subjected to a force of 300 N or more in some cases, and even 500 N or more in others. Furthermore, such a mobility scooter is used almost daily over a long period. Therefore, the poor support elements, as shown in PTL 1, would shift in their position supporting the rollers, deform, or break, thus significantly reducing the omnidirectional wheel's performance.

[0004] In view of this situation, it is an object of the present invention to improve an omnidirectional wheel with regard to its assembly. [Solution to the problem]

[0005] The invention relates to an omnidirectional wheel whose outer circumferential surface is formed with a plurality of rollers and which rotates about an axis of rotation of an axle, wherein the omnidirectional wheel comprises: a rotating part which rotates about the axis of rotation of the axle; and a plurality of supports which are arranged in a circumferential direction of the rotating part and of which each is mounted on the rotating part to support the plurality of rollers on the rotating part, wherein the plurality of rollers comprises a plurality of first rollers and a plurality of second rollers with a different outer diameter than the first rollers, wherein the first rollers and the second rollers alternate in the circumferential direction, wherein each of the supports has a first arm element which supports an end side in an axial direction of a corresponding first roller which corresponds to one of the plurality of first rollers, and has a second arm element.which supports the other end in the axial direction of the corresponding first roller, and wherein a corresponding second roller, corresponding to one of the plurality of second rollers, is supported by the first arm element of one of two supports adjacent to each other in the circumferential direction, and the second arm element of the other of the two supports. One end is supported in the axial direction of the corresponding first roller by an end of the first arm element, the other end of the first arm element being mounted on the rotating part, and the other end is supported in the axial direction of the corresponding first roller by an end of the second arm element, the other end of the second arm element being mounted on the rotating part. Brief description of the drawings Fig. Figure 1 is a sectional view of an omnidirectional wheel according to a first embodiment of the present invention. Fig. Figure 2 is a perspective view of the omnidirectional wheel according to the first embodiment. Fig. Figure 3 is a perspective view of the omnidirectional wheel according to the first embodiment, with some rollers removed. Fig. Figure 4 is a perspective partial section view of the omnidirectional wheel according to the first embodiment. Fig. Figure 5 is a perspective view of an electric vehicle in which the omnidirectional wheel according to the first embodiment is used. Fig. Figure 6 is a schematic floor view of the electric vehicle in which the omnidirectional wheel is used according to the first embodiment. Fig. Figure 7 is a perspective view of a support inserted in the omnidirectional wheel according to the first embodiment. Fig. Figure 8 is a perspective view of a first arm element inserted into the omnidirectional wheel according to the first embodiment. Fig. Figure 9 is a front view of the first arm element and a second arm element inserted in the omnidirectional wheel according to the first embodiment. Fig. Figure 10 is a top view of the first arm element and the second arm element inserted in the omnidirectional wheel according to the first embodiment. Fig. Figure 11 is a sectional view of the omnidirectional wheel according to the first embodiment. Fig. 12 is a sectional view along line XII-XII in Fig. 1. Fig. Figure 13 is a sectional view of an omnidirectional wheel according to a first modified example of the first embodiment. Fig. Figure 14 is a sectional view of an omnidirectional wheel according to a second modified example of the first embodiment. Fig. Figure 15 is a sectional view of an omnidirectional wheel according to a third modified example of the first embodiment. Fig. Figure 16 is a sectional view of an omnidirectional wheel according to a fourth modified example of the first embodiment. Fig. Figure 17 is a sectional view of an omnidirectional wheel according to a second embodiment of the present invention. Fig. Figure 18 is a sectional view of a first modified embodiment. Fig. Figure 19 is a perspective partial sectional view showing a second modified embodiment of the invention. Fig. Figure 20 is a perspective view of a third modified embodiment. Fig. Figure 21 is a perspective view of a first arm element and a second arm element of the third modified embodiment. Fig. 22 is a sectional view along line XXII-XXII in Fig. 1. [Description of the embodiments]

[0006] An omnidirectional wheel 1 according to a first embodiment of the present invention is described below with reference to the figures.

[0007] As in Fig. 4 and Fig. As shown in Figure 6, the omnidirectional wheel 1 has a pair of hub elements 20, 30 which are mounted on an axle 10 via a pair of bearings 10a arranged in the width direction. The hub elements 20, 30 thus function as rotating parts that rotate about a rotation axis RL.

[0008] As in Fig. 1, Fig. 2, Fig. As shown in Figure 4, etc., the outer circumferential surface of the omnidirectional wheel 1 is formed by a plurality of small-diameter rollers (first rollers) 40 and a plurality of large-diameter rollers (second rollers) 50, wherein the plurality of rollers 40, 50 are supported by a plurality of supports 60. The large-diameter roller 50 has a larger outer diameter than the small-diameter roller 40, with the multiple large-diameter rollers 50 and the multiple small-diameter rollers 40 alternating in one circumferential direction of the hub elements 20, 30. The plurality of supports 60 are each fastened to the hub elements 20, 30 by bolts (fastening elements) B.

[0009] In this embodiment, the hub elements 20, 30 are manufactured by stamping a plate-shaped metal part. Instead of the hub elements 20, 30, a disc-shaped block made of aluminum, etc., can also be used. In this case, this block acts as a rotating part that turns about the axis of rotation RL, with each of the multiple supports 60 being attached to an outer circumferential side of the block by the bolt (fastener) B. Optionally, rivets (fasteners) can be used instead of bolts, or shafts (fasteners) can be used that are attached to the hub elements 20, 30 by welding. Other commonly known fasteners can also be used.

[0010] As in Fig. As shown in Figure 1, each small-diameter roller 40 has a substantially cylindrical core element 41, an outer circumferential element 42 connected to an outer circumferential surface of the core element 41, and a shaft 43 arranged in a hole 41a formed in the core element 41. The hole 41a extends axially along the small-diameter roller 40. The core element 41 can be made of metal, such as aluminum or iron, or of plastic. In this embodiment, the outer circumferential element 42 is made of a material with rubber-like elasticity, such as silicone, and in one example is vulcanized to the outer circumferential surface of the core element 41.

[0011] The shaft 43 is made of metal, e.g., iron or aluminum. The core element 41 is mounted on the shaft 43 via bearings 44, allowing the core element 41 to rotate about an axis of rotation RL1 relative to the shaft 43. An inner circumferential surface of the hole 41a of the core element 41 has steps against which the bearings 44 rest, and an outer circumferential surface of the shaft 43 also has steps against which the bearings 44 rest. It is also possible to use a structure in which a sleeve is arranged on the outer circumferential surface of the shaft 43 and the bearings 44 rest against this sleeve.

[0012] As in Fig. As shown in Figure 1, each large-diameter roller 50 has a core element 51 with a substantially cylindrical outer circumferential portion 51b, an outer circumferential element 52 connected to an outer circumferential surface of the outer circumferential portion 51b, and a shaft 53 arranged in a hole 51a formed in the core element 51. The hole 51a extends axially along the large-diameter roller 50. The core element 51 can be made of metal, such as aluminum or iron, or of plastic. In this embodiment, the outer circumferential element 52 is made of a material with rubber-like elasticity, such as silicone, and in one example is vulcanized to the outer circumferential surface of the outer circumferential portion 51b of the core element 51.

[0013] In this embodiment, the core element 51 has the outer circumferential part 51b, an inner circumferential part 51c arranged on an inner surface radially to the outer circumferential part 51b, and an intermediate part 51d connecting the outer circumferential part 51b and the inner circumferential part 51c. The intermediate part 51d extends radially around the large-diameter roller 50. An inner circumferential surface of the outer circumferential part 51b is provided with a plurality of ribs (not shown). Each rib leads to the intermediate part 51d and / or the inner circumferential part 51c. The hole 51a is formed in the inner circumferential part 51c.

[0014] The shaft 53 is made of metal, such as iron or aluminum. The core element 51 is supported by the shaft 53 via bearings 54, allowing the core element 51 to rotate about a rotational axis RL2 relative to the shaft 53. An inner circumferential surface of the hole 51a of the core element 51 has steps against which the bearings 54 rest, and an outer circumferential surface of the shaft 53 also has steps against which the bearings 54 rest. Alternatively, a structure can be used in which a sleeve is arranged on the outer circumferential surface of the shaft 53, with the bearings 54 resting against this sleeve.

[0015] As in Fig. As shown in Figure 1, each support 60 has a first arm element 70 that supports one end side in an axial direction of a corresponding small-diameter roller 40, which corresponds to one of the plurality of small-diameter rollers 40, and a second arm element 80 that supports the other end side in the axial direction of the corresponding small-diameter roller 40. In this embodiment, the first arm element 70 supports one end side in the axial direction of the shaft 43 of the corresponding small-diameter roller 40 (corresponding first roller), and the second arm element 80 supports the other end side in the axial direction of the shaft 43 of the corresponding small-diameter roller 40.

[0016] As in Fig. As shown in Figure 1, a corresponding large-diameter roller (corresponding second roller) 50, which corresponds to one of the plurality of large-diameter rollers 50, is supported by the first arm element 70 by one of two supports 60 that adjoin each other in the circumferential direction of the hub elements 20, 30, wherein the second arm element 80 is supported by the other of the two supports 60. In this embodiment, the second arm element 80 supports one end face in the axial direction of the shaft 53 of the corresponding large-diameter roller 50, wherein the first arm element 70 supports the other end face in the axial direction of the shaft 53 of the corresponding large-diameter roller 50.

[0017] In some cases, the small-diameter roller 40 is not provided with the shaft 43. In this case, the bearing 44 can be supported at one end in the axial direction of the corresponding small-diameter roller 40 by the first arm element 70, while the bearing 44 can be supported at the other end in the axial direction of the corresponding small-diameter roller 40 by the second arm element 80.

[0018] In some cases, the large-diameter roller 50 is not provided with the shaft 53. In this case, the bearing 54 can be supported at one end in the axial direction of the corresponding large-diameter roller 50 by the second arm element 80, while the bearing 54 can be supported at the other end in the axial direction of the corresponding large-diameter roller 50 by the first arm element 70.

[0019] Arm elements 70 and 80 are made of metal, such as aluminum, and are manufactured by casting. Arm elements 70 and 80 can be formed by sintering metal powder. Arm elements 70 and 80 can consist of metal sheets, such as iron sheets, and are formed by pressing. Arm elements 70 and 80 can be made of metal, plastic, or both. Arm elements 70 and 80 can consist of metal, such as aluminum or iron, and are formed by casting.

[0020] As in Fig. As shown in Figure 9, a support part 71 for a small diameter roller is provided at one end side of the first arm element 70, which supports one end side of the corresponding small diameter roller 40, wherein a first fixed part 72 is provided at the other end side of the first arm element 70, which is attached to the hub elements 20, 30.

[0021] As in Fig. 7 to Fig. As shown in Figure 10, the first arm element 70 further comprises a base end part 73 extending from the first fixed part 72 and mainly in the axial direction of the corresponding small-diameter roller 40, a large-diameter roller support part 74 supporting the large-diameter roller 50, and a connecting part 75 connecting the large-diameter roller support part 74 and the small-diameter roller support part 71.

[0022] The support part 71 for the small diameter roller is provided with a hole 71a into which a bolt (fastening element) B1 for the small diameter roller, which will be described later, is screwed, wherein the support part 74 for the large diameter roller is provided with a hole 74a through which a bolt (fastening element) B2 for the large diameter roller, which will be described later, passes.

[0023] In this embodiment, a plane CL, which includes a centerline of hole 71a and a centerline of hole 74a, is the center of the first arm element 70 in a predetermined direction along the axis of rotation RL. The first fixed part 72 is not located at the position exactly in the center relative to this center, but at a position offset from this center in the predetermined direction (see Fig. 10). In this embodiment, the position of one end of the first fixed part 72 in the predetermined direction coincides with the position of the plane CL.

[0024] The center of the base end-side part 73 in a width direction can be the center of the first arm element 70 in the predetermined direction along the axis of rotation RL.

[0025] In this embodiment, the base end-part 73 has a substantially plate-like shape, wherein the position of the center of the base end-part 73 in the predetermined direction is also the position of the center line CL. In this embodiment, at least the thickness dimension or the width dimension of the base end-part 73 gradually decreases towards one end of the first arm element 70.

[0026] A distal end section of the base end section 73 bends in a direction along the axis of rotation RL2 of the corresponding large-diameter roller 50, with the support section 74 for the large-diameter roller being provided at a distal end of the base end section 73. In this embodiment, the support section 74 for the large-diameter roller has a base section 74b extending from the distal end of the base end section 73 toward an outer side in the radial direction of the hub elements 20, 30, and a cylindrical section 74c extending from or near the base section 74b in a direction along the axis of rotation RL2 of the corresponding large-diameter roller 50. The cylindrical section 74c projects from the base section 74b in a direction away from the first stationary part 72.In this embodiment, the radial direction of the hub elements 20, 30 and the radial direction of the omnidirectional wheel 1 coincide.

[0027] The inner diameter of the cylindrical section 74c is slightly larger than the outer diameter of the other end face in the axial direction of the shaft 53 of the large-diameter roller 50. Or the inner diameter of the cylindrical section 74c is equal to the outer diameter of the other end face in the axial direction of the shaft 53.

[0028] When the other end of the shaft 53 of the corresponding large-diameter roller 50 is inserted into the cylindrical section 74c in the axial direction, a distal end face of the cylindrical section 74c presses against an inner ring of the bearing 54, causing the inner ring of the bearing 54 to press against the step on the other end of the shaft 53 of the corresponding large-diameter roller 50.

[0029] In some cases, the support part 74 for the large-diameter roller does not have the cylindrical section 74c. In this case, the base section 74b is provided with a countersunk bore, with one end section of the shaft 53 fitted into this countersunk bore. In some cases, the support part 74 for the large-diameter roller has a different structure that can support the other end of the corresponding large-diameter roller 50.

[0030] A structure can be used in which an inner circumferential surface of the large-diameter shaft 53 of the roller 50 fits onto an outer circumferential surface of the cylindrical section 74c of the large-diameter support part 74 of the roller. In this case, the inner ring of the bearing 54 fits onto the outer circumferential surface of the cylindrical section 74c. Alternatively, the inner ring of the bearing 54 fits onto the outer circumferential surface of the shaft 53. In this case, an end face of the shaft 53 is pressed axially against the inner ring of the bearing 54, with an outer ring of the bearing 54 fitting onto an inner circumferential surface of the inner circumferential part 51c. Optionally, the shaft 53 can be omitted, in which case the outer ring of the bearing 54 can be mounted on the inner circumferential surface of the inner circumferential part 51c.

[0031] Furthermore, the inner circumferential surface of the inner circumferential part 51c of the large-diameter roller 50 can be formed in a smaller size, wherein the shaft 53 of the large-diameter roller 50 can be attached to the inner circumferential part 51c by fitting or the like. In such a configuration, the shaft 53 can be omitted, wherein the inner circumferential part 51c can have a shape in which the shaft 53 is integrated.

[0032] In this configuration, the outer ring of the bearing 54 can be mounted on an inner circumferential surface of the cylindrical section 74c of the support part 74 of the large-diameter roller, while the inner ring of the bearing 54 can be mounted on the outer circumferential surface of the shaft 53 or on the outer circumferential surface of the inner circumferential part 51c. In these cases as well, the large-diameter roller 50 is rotatably mounted by the support part 74 of the large-diameter roller.

[0033] In this embodiment, the support part 71 for the small-diameter roller has a base section 71b extending radially outwards from the hub elements 20, 30, and a cylindrical section 71c extending from or near the base section 71b in a direction along the axis of rotation RL1 of the corresponding small-diameter roller 40. The cylindrical section 71c projects from the base section 71b in the direction of the first stationary part 72.

[0034] The inner diameter of the cylindrical section 71c is slightly larger than the outer diameter of an end face in the axial direction of the shaft 43 of the small-diameter roller 40. Or, the inner diameter of the cylindrical section 71c is equal to the outer diameter of an end face in the axial direction of the shaft 43.

[0035] When an end face of the corresponding small-diameter roller 40 is inserted into the cylindrical section 71c in the axial direction of the shaft 43, a distal end face of the cylindrical section 71c is pressed against an inner ring of the bearing 44, and thereby the inner ring of the bearing 44 is pressed against the step on an end face of the shaft 43 of the corresponding small-diameter roller 40.

[0036] In some cases, the support part 71 for the small-diameter roller does not have the cylindrical section 71c. In this case, the base section 71b is provided with a countersunk bore, with one end section of the shaft 43 fitted into this countersunk bore. In some cases, the support part 71 for the small-diameter roller has a different structure that can support the other end of the corresponding small-diameter roller 40.

[0037] A structure can be formed in which an inner circumferential surface of the small-diameter shaft 43 of the roller 40 fits onto an outer circumferential surface of the cylindrical section 71c of the support element for a small-diameter roller 71. In this case, the inner ring of the bearing 44 fits onto the outer circumferential surface of the cylindrical section 71c. Alternatively, the inner ring of the bearing 44 fits onto the outer circumferential surface of the shaft 43. In this case, an end face of the shaft 43 is pressed axially against the inner ring of the bearing 44, with an outer ring of the bearing 44 fitting onto an inner circumferential surface of the core element 41. Optionally, the shaft 43 can be omitted, in which case the outer ring of the bearing 44 can be placed onto the inner circumferential surface of the core element 41.

[0038] Furthermore, the inner circumferential surface of the core element 41 of the small-diameter roller 40 can be formed in a smaller size, wherein the shaft 43 of the small-diameter roller 40 can be attached to the core element 41 by fitting or the like. In such a configuration, the shaft 43 can be omitted, wherein the core element 41 can have a shape in which the shaft 43 is integrated.

[0039] In this configuration, the outer ring of the bearing 44 can be mounted on the inner circumferential surface of the cylindrical section 71c of the small-diameter support element 71, while the inner ring of the bearing 44 can be mounted on the outer circumferential surface of the shaft 43 or the outer circumferential surface of the core element 41. In these cases as well, the small-diameter roller 40 is rotatably supported by the small-diameter roller support element 71.

[0040] The connecting element 75 connects the support element 74 for the large-diameter roller and the support element 71 for the small-diameter roller. In this embodiment, the connecting element 75 connects the base section 74b of the support element 74 for the large-diameter roller and the base section 71b of the support element 71 for the small-diameter roller. The connecting element 75 can also connect a different section of the support element 74 for the large-diameter roller and a different section of the support element 71 for the small-diameter roller.

[0041] The connecting part 75 extends mainly in the direction of the rotation axis RL2 of the corresponding large-diameter roller 50, when viewed from the direction of extension of the rotation axis RL, i.e., when the first arm element 70 is as shown in Fig. 1 or Fig. 9 is shown. In this embodiment, when the first arm element 70 is as shown in Fig. As shown in Figure 9, the extension direction of the connecting part 75 is the extension direction of a straight line connecting a center point P1 of the connecting part 75 on the side of the support part 71 for the small diameter roller and a center point P2 of the connecting part 75 on the side of the support part 74 for the large diameter roller.

[0042] It can be said that the connecting part 75 extends mainly in the direction of the axis of rotation RL2 if the angle formed by the direction of extension of the connecting part 75 and the direction of rotation RL2, as viewed from the direction of extension of the axis of rotation RL, is not greater than 30°. It can be said that the connecting part 75 preferably extends mainly in the direction of rotation RL2 if the angle formed by the direction of extension of the connecting part 75 and the direction of rotation RL2 is not greater than 20°. It can be said that the connecting part 75 even more preferably extends mainly in the direction of rotation RL2 if the angle between the direction of extension of the connecting part 75 and the direction of rotation RL2 is not greater than 15°.

[0043] As in Fig. As shown in Figure 9, a support part 81 for a small diameter roller, which supports the other end side of the corresponding small diameter roller 40, is provided at one end side of the second arm element 80, wherein a second fixed part 82, which is attached to the hub elements 20, 30, is provided at the other end side of the second arm element 80.

[0044] As in the Fig. As shown in Figures 7 to 10, the second arm element 80 further comprises a base end part 83 extending from the second fixed part 82 and mainly in the axial direction of the corresponding small diameter roller 40, a large diameter roller support part 84 supporting the large diameter roller 50, and a connecting part 85 connecting the large diameter roller support part 84 and the small diameter roller support part 81.

[0045] The support part 81 for the small diameter roller is provided with a hole 81a through which the bolt B1 for the small diameter roller described below passes, the support part 84 for the large diameter roller is provided with a hole 84a into which the bolt B2 for the large diameter roller described below is screwed.

[0046] In this embodiment, a plane CL including a centerline of hole 81a and a centerline of hole 84a is the center of the second arm element 80 in a predetermined direction along the axis of rotation RL. The second fixed part 82 is not located exactly in the center relative to this center, but rather at a position offset in the predetermined direction relative to this center (see Fig. 10) In this embodiment, the position of one end of the second fixed part 82 coincides with the position of the plane CL in the predetermined direction. The first fixed part 72 and the second fixed part 82 are arranged side by side in the predetermined direction, with the first fixed part 72 and the second fixed part 82 being located on opposite sides with respect to the center.

[0047] The center of the base end-side part 83 in the width direction can be the center of the second arm element 80 in the predetermined direction along the rotation axis RL.

[0048] In this embodiment, the base end-part 83 has a substantially plate-like shape, wherein the position of the center of the base end-part 83 in the predetermined direction is also the position of the center line CL. In this embodiment, at least one thickness dimension or one width dimension of the base end-part 83 gradually decreases towards an end side of the second arm element 80.

[0049] A distal end section of the base end section 83 bends in a direction along the axis of rotation RL2 of the corresponding large-diameter roller 50, with the support section 84 for the large-diameter roller being provided at a distal end of the base end section 83. In this embodiment, the support section 84 for the large-diameter roller has a base section 84b extending from the distal end of the base end section 83 toward the outside in the radial direction of the hub elements 20, 30, and a cylindrical section 84c extending from or near the base section 84b in a direction along the axis of rotation RL2 of the corresponding large-diameter roller 50. The cylindrical section 84c projects from the base section 84b in a direction away from the second fixed part 82.

[0050] The inner diameter of the cylindrical section 84c is slightly larger than the outer diameter of an end face in the axial direction of the shaft 53 of the large-diameter roller 50. Or, the inner diameter of the cylindrical section 84c is equal to the outer diameter of an end face in the axial direction of the shaft 53.

[0051] When an end face of the corresponding large-diameter roller 50 is inserted into the cylindrical section 84c in the axial direction of the shaft 53, a distal end face of the cylindrical section 84c is pressed against an inner ring of the bearing 54, thereby pressing the inner ring of the bearing 54 against the step on an end face of the shaft 53 of the corresponding large-diameter roller 50.

[0052] In some cases, the support part 84 for the large-diameter roller does not have the cylindrical section 84c. In this case, the base section 84b is provided with a countersunk bore, with one end section of the shaft 53 fitted into this countersunk bore. In some cases, the support part 84 for the large-diameter roller has a different structure that can support the other end of the corresponding large-diameter roller 50.

[0053] In this embodiment, the support part 81 for the small-diameter roller has a base section 81b extending radially outwards from the hub elements 20, 30, and a cylindrical section 81c extending from or near the base section 81b in a direction along the axis of rotation RL1 of the corresponding small-diameter roller 40. The cylindrical section 81c projects from the base section 81b in the direction of the second stationary part 82.

[0054] The inner diameter of the cylindrical section 81c is slightly larger than the outer diameter of the other end face in the axial direction of the shaft 43 of the small-diameter roller 40. Or, the inner diameter of the cylindrical section 81c is equal to the outer diameter of the other end face in the axial direction of the shaft 43.

[0055] When the other end of the shaft 43 of the corresponding small-diameter roller 40 is inserted into the cylindrical section 81c in the axial direction, a distal end face of the cylindrical section 81c is pressed against the inner ring of the bearing 44, thereby pressing the inner ring of the bearing 44 against the step on the other end of the shaft 43 of the corresponding small-diameter roller 40.

[0056] In some cases, the support part 81 for the small-diameter roller does not have the cylindrical section 81c. In this case, the base section 81b is provided with a countersunk bore, with one end section of the shaft 43 fitting into this countersunk bore. In some cases, the support part 81 for the small-diameter roller has a different structure that can support the other end of the corresponding small-diameter roller 40.

[0057] The connecting element 85 connects the support element 84 for the large-diameter roller and the support element 81 for the small-diameter roller. In this embodiment, the connecting element 85 connects the base section 84b of the support element 84 for the large-diameter roller and the base section 81b of the support element 81 for the small-diameter roller. The connecting element 85 can also connect a different section of the support element 84 for the large-diameter roller and a different section of the support element 81 for the small-diameter roller.

[0058] The connecting part 85 extends mainly in the direction of the rotation axis RL2 of the corresponding large-diameter roller 50 when viewed from the direction of extension of the rotation axis RL, i.e., when the second arm element 80 is as shown in Fig. 1 or Fig. Figure 9 is shown. The definition of the extension direction of the connecting part 85 is the same as the definition of the extension direction of the connecting part 75 of the first arm element 70.

[0059] As in Fig. 1 and Fig. As shown in Figure 3, the bolt B2 of the large-diameter roller passes through the hole 74a of the first arm element 70 and the shaft 53 of the large-diameter roller 50, and is screwed into the hole 84a of the second arm element 80. In this way, the corresponding large-diameter roller 50 is supported by a pair of adjacent supports 60. If the hole 84a is not internally threaded, then a nut is provided near the hole 84a.

[0060] The bolt B1 of the small-diameter roller passes through the hole 81a of the second arm element 80 and the shaft 43 of the small-diameter roller 40, and is screwed into the hole 71a of the first arm element 70. In this way, the corresponding small-diameter roller 40 is supported by the support 60. If hole 71a is not internally threaded, a nut is provided near hole 71a. If the nut is made of a material with a higher strength than aluminum, such as iron, the small-diameter roller 40 can be securely fastened by the small-diameter bolt B1. The nut can be fitted into a hole provided in the first arm element 70.

[0061] The first fixed part 72 is provided with a hole 72a extending through the first fixed part 72 in a direction along the axis of rotation RL, and the second fixed part 82 is also provided with a hole 82a extending through the second fixed part 82 in a direction along the axis of rotation RL.

[0062] As in Fig. As shown in Figure 4, the hub elements 20 and 30 have holes 21 and 31 formed at positions corresponding to the small-diameter roller 40. The bolt B passes through hole 21 of hub element 20, hole 72a of the first fixed part 72, hole 82a of the second fixed part 82, and hole 31 of hub element 30, and is screwed into a threaded hole of a nut N. Therefore, the majority of supports 60 are mounted on the hub elements 20 and 30, respectively. Hub element 30 may also have a threaded hole. Fig. Figure 3 shows a state where the shafts 43, 53 are attached to the supports 60.

[0063] In one direction along the rotation axis RL1 of the corresponding small-diameter roller 40, the positions of the first fixed part 72 and the second fixed part 82 are aligned with a central position of the corresponding small-diameter roller 40.

[0064] In this embodiment, a section in which the second fixed part 82 is not provided in the base end of the base end part 83 of the second arm element 80, which is attached as described above, touches the first fixed part 72 or the base end part 73 of the first arm element 70, or is located near the first fixed part 72 or the base end part 73 (see Fig. 7 and Fig. 9) Therefore, if the second arm element 80 is subjected to a large force in a wheel radial direction, wheel transverse direction or similar, deformation of the base end part 83 of the second arm element 80 is limited by the first fixed part 72 or the base end part 73.

[0065] Furthermore, a section in which the first fixed part 72 is not provided at the base end of the base end part 73 of the first arm element 70, which is attached as described above, touches the second fixed part 82 or the base end part 83 of the second arm element 80, or is located near the second fixed part 82 or the base end part 83. Thus, if the first arm element 70 is subjected to a large force in the wheel radial direction, the wheel lateral direction, or similar, deformation of the base end part 73 of the first arm element 70 by the second fixed part 82 or the base end part 83 is limited.

[0066] In this embodiment, the first arm element 70 and the second arm element 80 are identical, except that hole 71a is an internal threaded hole, while hole 81a is a through hole, and hole 74a is a through hole, while hole 84a is an internal threaded hole. Thus, the first arm element 70 and the second arm element 80 have the same shape, at least with the exception of holes 71a, 74a, 81a, and 84a, and conversely, the shape of the first arm element 70 corresponds to the shape of the second arm element 80. This configuration is advantageous for reducing manufacturing costs.

[0067] In the manufacture of the omnidirectional wheel 1, the large-diameter roller 50 is supported between a pair of supports 60 by the bolt B2 for the large-diameter roller, wherein the small-diameter roller 40 is then supported on one of the pairs of supports 60 by the bolt B1 for the small-diameter roller, and subsequently another large-diameter roller 50 is supported in the same way. By repeating this process, the majority of the rollers 40, 50 are coupled together in the circumferential direction of the omnidirectional wheel 1.

[0068] As in Fig. As shown in Figure 1, each end section of the large-diameter roller 50 has a recess 55 in the axial direction into which a section of one end of the small-diameter roller 40 enters. Since a section of one end of the small-diameter roller 40 is located within the recess 55 of the large-diameter roller 50, the circumferential distance between the small-diameter roller 40 and the large-diameter roller 50 is reduced.

[0069] In the circumferential coupling of rollers 40 and 50 described above, when the last roller of the majority of rollers 40 is attached to the support 60 by means of bolt B1 for the small-diameter roller, the head of this bolt B1 for the small-diameter roller cannot be turned with a tool. This is due to Fig. 1 etc. is evident.

[0070] To solve this problem, for example, as in Fig. Figure 11 shows a first roller group G1 and a second roller group G2, each comprising at least one roller 40 with a small diameter and at least one roller 50 with a large diameter. In each of the roller groups G1, G2, the rollers with a large diameter 50 and the rollers 40 with a small diameter are supported on the supports 60 by the bolts B1, B2. It is also possible to form three or more roller groups.

[0071] As in Fig. 1 and Fig. As shown in Figure 11, to connect the plurality of roller groups G1, G2, the small-diameter roller 40, located at one end in each of the roller groups G1, G2, has a hole 40a extending from the outer circumferential surface of the small-diameter roller 40 to the inner circumferential surface of the shaft 43 of the small-diameter roller 40. An outer circumferential surface of the bolt B1 for the small-diameter roller 40 has a chamfered section (engagement section) 90 formed at a position corresponding to the hole 40a.

[0072] As in Fig. 1 and Fig. As shown in Figure 12, the chamfered section 90 has a first flat surface part 91, a second flat surface part 92 which is located at a different position than the first flat surface part 91 in a circumferential direction of the outer circumferential surface of the small diameter bolt B1, and a curved surface 93 which connects the first flat surface part 91 and the second flat surface part 92.

[0073] The hole 40a extends through the outer circumferential element 42, the core element 41, and the shaft 43 of the small-diameter roller 40. For example, a portion of the hole 40a provided in the core element 41 or in the shaft 43 has an internal thread.

[0074] A screw element 94 is screwed onto the internal thread, with a screwdriver being inserted into a groove formed in one end face of the screw element 94 to secure the screw element 94 towards the small-diameter bolt B1. In this way, the screw element 94 engages in the chamfered section 90. In this state, the small-diameter roller 40 is rotated in a predetermined direction using a tool, by hand, etc., so that the bolt B1 of the small-diameter roller rotates together with the small-diameter roller 40 and the bolt B1 of the small-diameter roller is screwed into the hole 71a of the first arm element 70. In this way, the shaft 43 of the small-diameter roller 40 is fastened to the first arm element 70 and the second arm element 80 by the bolt B1 to the small-diameter roller.This process can be carried out in a state where some of the supports 60 are mounted on the hub elements 20, 30, or the supports 60 can be mounted on the hub elements 20, 30 after the rollers 40, 50 have been coupled together.

[0075] The screw element 94 is then moved radially towards the outside of the small-diameter roller 40 using a screwdriver. This causes the small-diameter roller 40 to rotate. In some cases, the screw element 94 acts as a closing element, sealing the hole 40a. Alternatively, a closing element 95 can be mounted on the hole 40a, as shown in Fig. 1 shown after the screw element 94 was removed from hole 40a ( Fig. 12).

[0076] On the other hand, the multiple small-diameter rollers 40 and the multiple large-diameter rollers 50 can be coupled one after the other by inserting the multiple first arm elements 70, the multiple second arm elements 80, the multiple bolts B1 of the small-diameter rollers and the multiple bolts B2 of the large-diameter rollers, wherein the bolt B1 of the small-diameter roller can be screwed from the last small-diameter roller 40 into the first arm element 70.

[0077] When the bolt B1 of the small-diameter roller is fastened in the hole 71a of the first arm element 70, the small-diameter roller 40 and the screw element 94 rotate in the direction of arrow A in Fig. 12, wherein the screw element 94 engages with the first flat surface part 91. Here, the chamfered section 90 has the second flat surface part 92 and the curved surface part 93. Therefore, when the small-diameter roller 40 is rotated in the direction opposite to arrow A, the screw element 94 moves from the first flat surface part 91 to the second flat surface part 92 through the curved surface part 93.

[0078] In some cases, after the small-diameter roller's bolt B1 has been tightened, the hole 40a on the side of the support 60 is positioned in the direction of arrow A. In this state, the screw element 94 cannot be detached from the small-diameter roller's bolt B1, and the small-diameter roller cannot rotate. If the second flat surface part 92 and the curved surface part 93 are provided, the small-diameter roller 40 can be moved in the opposite direction of arrow A after the small-diameter bolt B1 has been tightened. Therefore, the hole 40a can be moved to a position that does not align with the support 60, and the screw element 94 can be moved away from the small-diameter roller's bolt B1.

[0079] As in Fig. As shown in Figure 13, it is also possible to provide the bolt B1 of the small-diameter roller with a hole 96 instead of the chamfered section 90. In this case, the hole 40a can extend radially through the small-diameter roller 40. The screw element 94 passes through the hole 96 and the hole 40a and is screwed onto an internal thread provided, for example, in the core element 41 or the shaft 43 inside the hole 40a. Rotating the small-diameter roller 40 in this state can secure the bolt B1 of the small-diameter roller in the first arm element 70. It is preferred that each end of the screw element 94 has a groove into which a screwdriver engages.

[0080] As in Fig. As shown in Figure 14, the large-diameter roller 50 can have a hole 50a near the head of the bolt B1 of the small-diameter roller, which is to be fastened last. This hole extends from the outer circumferential surface of the large-diameter roller 50 to the recess 55 of the large-diameter roller 50. In this case, a bolt turning tool passes through the hole 50a, and the small-diameter roller 40 can be fastened in the hole 71a of the first arm element 70 using the bolt turning tool. The hole 50a can be closed with a plug element 50b.

[0081] As in Fig. As shown in Figure 15, one end of the small-diameter shaft 43 of the roller 40, which is to be mounted last on the first arm element 70, can be fastened to the first arm element 70 by a fastening element 97. In this case, one end of the shaft 43 is provided with a hole extending radially through the shaft 43, and the first arm element 70 is also provided with a hole at a position corresponding to the hole in the shaft 43. The fastening element 97 is attached to the first arm element 70 in such a way that the fastening element 97 passes through both the hole in the first arm element 70 and the hole in the shaft 43. Thus, one end of the small-diameter shaft 43 of the roller 40 is fastened to the first arm element 70.

[0082] In this case, as in Fig. Figure 15 shows the other end of the shaft 43 of the small diameter roller 40 being attached to the second arm element 80 by a short bolt B1 of the small diameter roller.

[0083] Fastening element 97 is a pin, a bolt, a screw element, a rivet or similar metal component.

[0084] As in Fig. As shown in Figure 16, an end side of the shaft 43 of the roller 40 with a small diameter, which is to be attached last to the first arm element 70, can be attached to the first arm element 70 with an adhesive.

[0085] In each of the above embodiments, part or all of the shaft 43 can be solid in its longitudinal direction, as shown in Fig. 15 shown, or the entire shaft 43 may be hollow in its longitudinal direction.

[0086] The omnidirectional wheel 1 thus designed is used, for example, for the front wheels of an electric mobility vehicle 100, which is driven by a person sitting in a seat (see Fig. 5) The omnidirectional wheel 1 can be used for the rear wheels of the electric mobility vehicle 100 or for other wheels. It is also conceivable that the omnidirectional wheel 1 could be used as a wheel of another machine, such as a robot, or as a wheel of another vehicle.

[0087] For example, in Fig. 5 and Fig. As shown in Figure 6, the electric mobility vehicle 100 comprises omnidirectional wheels 1 as front wheels, rear wheels 120, and a mobility body 110 with a body 130 supported by the omnidirectional wheels 1 and the rear wheels 120. Furthermore, this electric mobility vehicle comprises a seat unit (seat) 140, which is detachably mounted on the mobility body 110, and drive devices 150, such as motors, which are mounted on the mobility body 110 and drive at least either the omnidirectional wheels 1 or the rear wheels 120.

[0088] When the omnidirectional wheel 1 is used for such an electric mobility vehicle, each of the rollers 40, 50 of the omnidirectional wheel 1 is subjected to a considerable force. It is not uncommon for an electric mobility vehicle to weigh 50 kg or more, with some electric vehicles weighing almost 100 kg. Electric vehicle drivers also vary in weight. Furthermore, electric vehicles sometimes climb over steps and sometimes travel on roads with many bumps and dips. Therefore, it is not unusual for each of the rollers 40, 50 to be subjected to a force of 300 N or more, and may even be subjected to a force exceeding 500 N. Additionally, such an electric mobility vehicle is operated almost daily for extended periods. Therefore, the omnidirectional wheel 1 must possess a high degree of strength and durability.

[0089] In this embodiment, each corresponding small-diameter roller 40 is supported by the support 60, with one end side in the axial direction of the corresponding small-diameter roller 40 being supported by the first arm element 70 and the other end side in the axial direction of the corresponding small-diameter roller 40 being supported by the second arm element 80. Each corresponding large-diameter roller 50 is supported by the first arm element 70 of one of the two supports 60, which are located next to each other circumferentially, and by the second arm element 80 of the other of the two supports 60. Thus, the small-diameter roller 40 is not supported by a single element, but by the first arm element 70 and the second arm element 80. The large-diameter roller 50 is supported at one end by the second arm element 80 and at the other end by the first arm element 70.

[0090] Compared to a configuration where the small-diameter roller 40 is supported by a single element, adjacent parts are more closely connected, making it more likely that a force exerted on the small-diameter roller 40 upon contact with a road surface will be transmitted to the adjacent large-diameter rollers 50. Conversely, a force exerted on the large-diameter rollers 50 is more likely to be transmitted to the adjacent small-diameter rollers 40. A force exerted on the large-diameter rollers 50 upon contact with the road surface is also more likely to be transmitted to the adjacent small-diameter rollers 40.This configuration makes it possible to effectively bear the force exerted on each of the rollers 40, 50 by the adjacent rollers 40, 50 and their arm elements 70, 80, while reducing the thicknesses of the first arm element 70 and the second arm element 80.

[0091] Compared to a configuration where the small-diameter roller 40 is supported by a single element, one end of the small-diameter roller 40 is more likely to be in the correct position relative to the first arm element 70 when the rollers 40, 50 and the supports 60 are mounted on the hub elements 20, 30. The other end of the small-diameter roller 40 is also more likely to be in the correct position relative to the second arm element 80. This configuration is advantageous for effectively distributing the force exerted on each of the rollers 40, 50 by the adjacent rollers 40, 50 and their arm elements 70, 80. In this way, it is possible to achieve a high degree of compatibility between increasing the force that each of the rollers 40, 50 can absorb and reducing the weight of the wheel.

[0092] In this embodiment, one end face of the corresponding small-diameter roller 40 is supported axially by one end face of the first arm element 70, the other end face of the first arm element 70 being mounted on the hub elements 20, 30. The other end face of the corresponding small-diameter roller 40 is supported axially by one end face of the second arm element 80, the other end face of the second arm element 80 being mounted on the rollers 40, 50.Thus, in the first arm element 70, the part that supports the corresponding small-diameter roller 40 and the part that is mounted on the hub elements 20, 30 are spaced apart from each other, so that a force exerted on the small-diameter roller 40 is more likely to be transmitted to the adjacent large-diameter rollers 50, and the force exerted on the large-diameter roller 50 is more likely to be transmitted to the adjacent small-diameter rollers 40.

[0093] Since the part supporting the corresponding small-diameter roller 40 and the part attached to the hub elements 20, 30 are spaced apart in the first arm element 70 when the rollers 40, 50 and the supports 60 are attached to the hub elements 20, 30, it is more likely that one end side of the first arm element 70 is in the correct position relative to one end side of the corresponding small-diameter roller 40, and that one end side of the second arm element 80 is more likely to be in the correct position relative to the other end side of the corresponding small-diameter roller 40.

[0094] In this embodiment, each support 60 supports the corresponding small-diameter roller 40, with one end and the other end of the corresponding small-diameter roller 40 being attached to the first arm element 70 and the second arm element 80 by a bolt (fastening element) B1 for the small-diameter roller, extending in the axial direction of the corresponding small-diameter roller 40. This configuration makes it more likely that a force applied to the small-diameter roller 40 or the large-diameter roller 50 will be successively transmitted to the several adjacent small-diameter rollers 40 and large-diameter rollers 50.

[0095] In this embodiment, each pair of supports 60 supports the corresponding large-diameter roller 50, the corresponding large-diameter roller 50 being attached to the first arm element 70 and the second arm element 80 by bolt B2 (fastening element) of a large-diameter roller extending in the axial direction of the corresponding large-diameter roller 50. This configuration makes it more likely that a force exerted on the small-diameter roller 40 or the large-diameter roller 50 will be further transmitted to the majority of the adjacent small-diameter rollers 40 and large-diameter rollers 50.

[0096] In this embodiment, when viewed from the direction of extension of the axis of rotation RL, the connecting element 75, which connects the support element 71 for the small-diameter roller and the support element 74 for the large-diameter roller in the first arm element 70, extends primarily in the direction of the axis of rotation RL2 of the corresponding large-diameter roller 50. This configuration makes it more likely that a force exerted on the small-diameter roller 40 or the large-diameter roller 50 will be further transmitted to the majority of adjacent small-diameter rollers 40 and large-diameter rollers 50. Furthermore, this configuration is advantageous for reducing the thickness of the connecting element 75. In this embodiment, the connecting element 85 of the second arm element 80 has the same structure and produces the same effects.

[0097] In this embodiment, the other end of the first arm element 70 and the other end of the second arm element 80 overlap in the predetermined direction along the axis of rotation RL. In this embodiment, the first fixed part 72 at the other end of the first arm element 70 and the second fixed part 82 at the other end of the second arm element 80 overlap in the predetermined direction along the axis of rotation RL, the first fixed part 72 and the second fixed part 82 being mounted on the hub elements 20, 30. As described above, a force applied to the small-diameter roller 40 or the large-diameter roller 50 is more likely to be transmitted to the majority of adjacent small-diameter rollers 40 and large-diameter rollers 50.Thus, the omnidirectional wheel 1 of this embodiment can bear the force exerted on the small diameter rollers 40 and the large diameter rollers 50, while having a smaller number of parts.

[0098] In this embodiment, the single first fixed part 72 and the single second fixed part 82 overlap in the predetermined direction along the axis of rotation RL. This makes it possible to securely attach the first fixed part 72 and the second fixed part 82 to the hub elements 20, 30 without machining an end face in the predetermined direction of the first fixed part 72 and an end face in the predetermined direction of the second arm element 80. This helps to reduce the manufacturing costs of the arm elements 70, 80.

[0099] Optionally, the first arm element 70 can be provided with a plurality of first fixed parts 72, and the second arm element 80 can be provided with a plurality of second fixed parts 82, wherein the plurality of the first fixed parts 72 and the plurality of the second fixed parts 82 can alternate with each other in the predetermined direction.

[0100] In this embodiment, the first fixed part 72 is positioned in a location that is offset to one side in the predetermined direction relative to the center of the first arm element 70 along the axis of rotation RL. The second fixed part 82 is positioned in a location that is offset to the other side in the predetermined direction relative to the center of the second arm element 80 along the axis of rotation RL. This configuration ensures the rigidity of the first arm element 70 and the second arm element 80, which are mounted on the hub elements 20, 30, while simultaneously reducing the dimensions of the omnidirectional wheel 1 along the axis of rotation RL.

[0101] In this embodiment, at least one of the plurality of rollers 40, 50 has the hole 40a or 50a, which extends from the outer circumferential surface to the inner circumferential surface of the roller. In this embodiment, the multiple rollers 40, 50 are connected to form a ring using this hole 40a or 50a.

[0102] Holes 40a, 50a can be closed with the plug elements 95, 50b, which close holes 40a, 50a.

[0103] In this embodiment, the at least one roller is the small-diameter roller 40, wherein one end and the other end of the small-diameter roller 40 are axially attached to the support 60 by a bolt B1 of the small-diameter roller extending axially, the outer circumferential surface of the bolt B1 of the small-diameter roller having the chamfered section (engagement section) 90 or the hole (engagement section) 96 formed at the axial position corresponding to the hole 40a. Thus, when the screw element 94 is inserted into the hole 40a and the screw element 94 engages in the chamfered section 90 or the hole 96, the first roller 40 is rotated to secure the first bolt B1 of the first roller in the first arm element 70.

[0104] An omnidirectional wheel 1 according to a second embodiment of the present invention is described below with reference to the drawings.

[0105] As in Fig. As shown in Figure 17, the first arm element 70 and the second arm element 80 of the support 60 of the first embodiment are integrated into the omnidirectional wheel 1 of the second embodiment. The same components as shown in the first embodiment are designated with the same reference numerals, with the descriptions omitted.

[0106] In the omnidirectional wheel 1 of the first embodiment, the support 60 comprises the two parts, the first arm element 70 and the second arm element 80. In the omnidirectional wheel 1 of the second embodiment, the support 60 is instead a single piece, comprising a first arm 70 and a second arm 80. The first arm element 70 and the first arm 70 differ from each other only in the shape of the base end face and the shape of a portion of the distal end face, and are therefore designated by the same reference numeral. The second arm element 80 and the second arm 80 differ from each other only in the shape of the base end face and the shape of a portion of the distal end face, and are therefore designated by the same reference numeral.

[0107] The support 60 is made of metal, such as aluminum, and is formed by a housing. The support 60 can be manufactured by sintering metal powder. The support 60 can consist of a metal sheet, such as an iron plate, and be shaped by pressing. The support 60 can be made of metal, plastic, or both. The support 60 can consist of metal, such as aluminum or iron, and be shaped by casting.

[0108] As in Fig. As shown in Figure 17, a support element 71 of the small-diameter roller is provided to support one end of the corresponding small-diameter roller 40 at one end of the first arm 70. This support element has the same hole 71a and the same base section 71b as in the first embodiment. A fixed part 61, which is to be attached to the hub elements 20, 30, is provided at the other end of the first arm 70.

[0109] The first arm 70 further comprises a base end part 73 extending from the fixed part 61 mainly in the axial direction of the corresponding small-diameter roller 40, a large-diameter roller support part 74 supporting the large-diameter roller 50, and a connecting part 75 connecting the large-diameter roller support part 74 and the small-diameter roller support part 71.

[0110] A bolt B1 of the small diameter roller is screwed into the hole 71a provided in the support part 71 for the small diameter roller, wherein the support part 74 for the large diameter roller is provided with a hole 74a through which a bolt B2 of the large diameter roller passes.

[0111] In this embodiment, a plane containing the centerline of hole 71a and the centerline of hole 74a passes through the center of the first arm element 70 in a predetermined direction along the axis of rotation RL. The stationary part 61 is arranged in a central position relative to this center. The center of the base end part 73 in the lateral direction can form the center of the first arm element 70 in the predetermined direction along the axis of rotation RL.

[0112] A distal end section of the base end section 73 bends mainly in one direction along the axis of rotation RL2 of the corresponding large-diameter roller 50, with the support section 74 of the large-diameter roller being provided at a distal end of the base end section 73. In this embodiment, the support section 74 of the large-diameter roller has a base section 74b extending from the distal end of the base end section 73 toward the outside in the radial direction of the hub elements 20, 30, and a cylindrical section 74c extending from or near the base section 74b in one direction along the axis of rotation RL2 of the corresponding large-diameter roller 50. The cylindrical section 74c projects from the base section 74b in one direction away from the stationary part 61.In this embodiment, the radial direction of the hub elements 20, 30 and the radial direction of the omnidirectional wheel 1 coincide.

[0113] The inner diameter of the cylindrical section 74c is slightly larger than the outer diameter of the other end face in the axial direction of the shaft 53 of the large-diameter roller 50. Or the inner diameter of the cylindrical section 74c is equal to the outer diameter of the other end face in the axial direction of the shaft 53.

[0114] When the other end side of the shaft 53 of the corresponding large-diameter roller 50 is inserted into the cylindrical section 74c in the axial direction, a distal end face of the cylindrical section 74c is pressed against the inner ring of the bearing 54, and thereby the inner ring of the bearing 54 is pressed against the step on the other end side of the shaft 53 of the corresponding large-diameter roller 50.

[0115] In some cases, the support part 74 for the large-diameter roller does not have the cylindrical section 74c. In this case, the base section 74b is provided with a countersunk bore, with the end section of the shaft 53 fitting into this countersunk bore. In some cases, the support part 74 for the large-diameter roller has a different structure that can support the other end of the corresponding large-diameter roller 50.

[0116] In the second embodiment, the support part 71 for the small-diameter roller has a base section 71b extending radially outward from the hub elements 20, 30, and a semi-cylindrical section 71d extending from or near the base section 71b in a direction along the axis of rotation RL1 of the corresponding small-diameter roller 40. The semi-cylindrical section 71d projects from the base section 71b toward the stationary part 61. In the second embodiment, the semi-cylindrical section 71d replaces the cylindrical section 71c of the first embodiment.

[0117] The inner diameter of the semi-cylindrical section 71d is slightly larger than the outer diameter of one end face in the axial direction of the shaft 43 of the small-diameter roller 40. Or, the inner diameter of the semi-cylindrical section 71d is equal to the outer diameter of one end face in the axial direction of the shaft 43.

[0118] When an end face of the corresponding small-diameter roller 40 is inserted into the semi-cylindrical section 71d in the axial direction of the shaft 43, a distal end face of the semi-cylindrical section 71d is pressed against an inner ring of the bearing 44, and thereby the inner ring of the bearing 44 is pressed against the step on an end face of the shaft 43 of the corresponding small-diameter roller 40.

[0119] In some cases, the support part 71 for the small-diameter roller does not have the semi-cylindrical section 71d. In this case, the base section 71b is provided with a countersunk bore, and the end section of the shaft 43 is fitted into this countersunk bore. In some cases, the support part 71 for the small-diameter roller has a different structure that can support the other end of the corresponding small-diameter roller 40.

[0120] The connecting part 75 connects the support part 74 for the large-diameter roller and the support part 71 for the small-diameter roller. In this embodiment, the connecting part 75 connects the base section 74b of the support part 74 for the large-diameter roller and the base section 71b of the support part 71 for the small-diameter roller. The connecting part 75 can also connect a different section of the support part 74 of the large-diameter roller and a different section of the support part 71 of the small-diameter roller.

[0121] The connecting part 75 extends mainly in the direction of the rotation axis RL2 of the corresponding large-diameter roller 50, when viewed from the direction of extension of the rotation axis RL, i.e., when considering the first arm 70 as in Fig. Figure 17 shows the definition of the extension direction of the connecting part 75, which is the same as shown in the first embodiment.

[0122] The connecting part 75 can be said to extend mainly in the direction of the axis of rotation RL2 if the angle formed by the direction of extension of the connecting part 75 and the direction of the axis of rotation RL2, as seen from the direction of extension of the axis of rotation RL, is not greater than 30°. Preferably, the connecting part 75 can extend mainly in the direction of the axis of rotation RL2 if the angle formed by the direction of extension of the connecting part 75 and the direction of the axis of rotation RL2 is not greater than 20°. Even more preferably, the connecting part 75 can extend mainly in the direction of the axis of rotation RL2 if the angle between the direction of extension of the connecting part 75 and the direction of the axis of rotation RL2 is not greater than 15°.

[0123] As in Fig. As shown in Figure 17, a support part 81 for a small diameter roller, which supports one end side of the corresponding small diameter roller 40, is provided at one end side of the second arm 80, wherein the fixed part 61, which is shared by the first arm 70 and the second arm 80, is provided at the other end side of the second arm 80.

[0124] The second arm 80 further has a base end part 83, which extends from the fixed part 61 mainly in the axial direction of the corresponding small diameter roller 40, a support part 84 for the large diameter roller, which supports the large diameter roller 50, and a connecting part 85, which connects the support part 84 for the large diameter roller and the support part 81 for the small diameter roller.

[0125] The support part 81 for the small-diameter roller is provided with a hole 81a through which the bolt B1 for the small-diameter roller, described later, is inserted. The support part 84 for the large-diameter roller is provided with a hole 84a into which the bolt B2 for the large-diameter roller, described later, is screwed. If the hole 84a is not internally threaded, a nut is provided near the hole 84a. If the nut is made of a material with a higher strength than aluminum, such as iron, the large-diameter roller 50 can be securely fastened by the large-diameter bolt B2. The nut can be fitted into a hole provided in the second arm element 80.

[0126] In this embodiment, a plane containing the centerline of hole 81a and the centerline of hole 84a passes through the center of the second arm element 80 in a predetermined direction along the axis of rotation RL. The stationary part 61 is arranged in a central position relative to this center. The center of the base end part 83 in the lateral direction can form the center of the second arm element 80 in the predetermined direction along the axis of rotation RL.

[0127] A distal end section of the base end section 83 bends mainly in one direction along the axis of rotation RL2 of the corresponding large-diameter roller 50, with the support section 84 for the large-diameter roller being provided at a distal end of the base end section 83. In this embodiment, the support section 84 for the large-diameter roller has a base section 84b extending from the distal end of the base end section 83 to the outside in the radial direction of the hub elements 20, 30, and a cylindrical section 84c extending from or near the base section 84b in one direction along the axis of rotation RL2 of the corresponding large-diameter roller 50. The cylindrical section 84c projects from the base section 84b in one direction away from the stationary part 61.

[0128] The inner diameter of the cylindrical section 84c is slightly larger than the outer diameter of an end face in the axial direction of the shaft 53 of the large-diameter roller 50. Or, the inner diameter of the cylindrical section 84c is equal to the outer diameter of an end face in the axial direction of the shaft 53.

[0129] When an end face of the corresponding large-diameter roller 50 is inserted into the cylindrical section 84c in the axial direction of the shaft 53, a distal end face of the cylindrical section 84c is pressed against the inner ring of the bearing 54, thereby pressing the inner ring of the bearing 54 against the step on an end face of the shaft 53 of the corresponding large-diameter roller 50.

[0130] In some cases, the support part 84 for the large-diameter roller does not have the cylindrical section 84c. In this case, the base section 84b is provided with a countersunk bore, with the end section of the shaft 53 fitting into this countersunk bore. In some cases, the support part 84 of the large-diameter roller has a different structure that can support the other end of the corresponding large-diameter roller 50.

[0131] In the second embodiment, the support part 81 for the small-diameter roller has a base section 81b extending radially outward from the hub elements 20, 30, and a semi-cylindrical section 81d extending from or near the base section 81b in a direction along the axis of rotation RL1 of the corresponding small-diameter roller 40. The semi-cylindrical section 81d projects from the base section 81b toward the stationary part 61. In the second embodiment, the semi-cylindrical section 81d replaces the cylindrical section 81c of the first embodiment.

[0132] The inner diameter of the semi-cylindrical section 81d is slightly larger than the outer diameter of the other end face in the axial direction of the shaft 43 of the small-diameter roller 40. Or, the inner diameter of the semi-cylindrical section 81d is equal to the outer diameter of the other end face in the axial direction of the shaft 43.

[0133] When the other end side of the shaft 43 of the corresponding small-diameter roller 40 is inserted into the semi-cylindrical section 81d in the axial direction, a distal end surface of the semi-cylindrical section 81d is pressed against the inner ring of the bearing 44, and thereby the inner ring of the bearing 44 is pressed against the step on the other end side of the shaft 43 of the corresponding small-diameter roller 40.

[0134] In some cases, the support part 81 for the small diameter roller does not have the semi-cylindrical section 81d.

[0135] The connecting element 85 connects the support element 84 for the large-diameter roller and the support element 81 for the small-diameter roller. In this embodiment, the connecting element 85 connects the base section 84b of the support element 84 for the large-diameter roller and the base section 81b of the support element 81 for the small-diameter roller. The connecting element 85 can also connect a different section of the support element 84 for the large-diameter roller and a different section of the support element 81 for the small-diameter roller.

[0136] The connecting part 85 extends mainly in the direction of the rotation axis RL2 of the corresponding large-diameter roller 50, when viewed from the direction of extension of the rotation axis RL, i.e., when considering the second arm 80 as in Fig. Figure 17 shows the definition of the extension direction of the connecting part 85, which is the same as the definition of the extension direction of the connecting part 75 of the first arm 70.

[0137] In the second embodiment, the connecting element 75, which connects the support element 71 for the small-diameter roller and the support element 74 for the large-diameter roller, extends, viewed from the direction of extension of the axis of rotation RL, in the first arm 70 primarily in the direction of the axis of rotation RL2 of the corresponding large-diameter roller 50. This arrangement makes it more likely that a force exerted on the small-diameter roller 40 or the large-diameter roller 50 will be further transmitted to a plurality of adjacent small-diameter rollers 40 and large-diameter rollers 50. Furthermore, this configuration is advantageous for reducing the thickness of the connecting element 75. In this embodiment, the connecting element 85 of the second arm 80 has the same structure and produces the same effects.

[0138] In the first embodiment, as in Fig. As shown in Figure 18, the first fixed part 72 of the first arm element 70 and the second fixed part 82 of the second arm element 80 do not need to overlap in the direction along the axis of rotation RL. In this case, both the first fixed part 72 and the second fixed part 82 are attached to the hub elements 20, 30 by means of the bolt B.

[0139] In the first embodiment, as in Fig. As shown in Figure 19, a hub element H can be used instead of the two hub elements 20, 30. In this case, the first fixed part 72 of the first arm element 70 is arranged on one side in the thickness direction of the hub element H, and the second fixed part 82 of the second arm element 80 is arranged on the other side in the thickness direction of the hub element H. Optionally, the first fixed part 72 of the first arm element 70 and the second fixed part 82 of the second arm element 80 can be arranged on one side in the thickness direction of the hub element H. In this case as well, the first fixed part 72 and the second fixed part 82 are attached to the hub element H by the bolt B.

[0140] In the first embodiment, the configuration was shown in which each support 60 carries a small-diameter roller 40. Instead, as in Fig. 20 and Fig. As shown in Figure 21, the first arm element 70 and the second arm element 80 can also be configured such that each support 60 carries a large-diameter roller 50. In this case, the first arm element 70 supports one end in the axial direction of the shaft 53 of the corresponding large-diameter roller 50, and the second arm element 80 supports the other end in the axial direction of the shaft 53 of the corresponding large-diameter roller 50.

[0141] The corresponding small-diameter roller 40, which is one of a plurality of small-diameter rollers 40, is supported by the first arm element 70 of one of two supports 60 located side by side in the circumferential direction, and by the second arm element 80 of the other of the two supports 60. For example, the first arm element 70 supports one end in the axial direction of the shaft 43 of the corresponding small-diameter roller 40, and the second arm element 80 supports the other end in the axial direction of the shaft 43 of the corresponding small-diameter roller 40.

[0142] As in Fig. As shown in Figure 21, in this modified example the first fixed part 72 is long at the other end of the first arm element 70, but the configuration of the first arm element 70 is otherwise the same as shown in the first embodiment. In particular, the first fixed part 72 is provided with the hole 72a; the base end part 73 extends from the first fixed part 72 in the axial direction of the small-diameter roller 40; the support part 74 for the large-diameter roller is provided at the distal end of the base end part 73; the support part 71 for the small-diameter roller is provided at one end of the first arm element 70; and the connecting part 75, which connects the support part 74 for the large-diameter roller and the support part 71 for the small-diameter roller, is formed.In the same way as in the first embodiment, the connecting part 75 extends mainly in the direction of the axis of rotation RL2 of the corresponding large-diameter roller 50, as seen from the direction of extension of the axis of rotation RL.

[0143] Furthermore, the second fixed part 82 is long at the other end of the second arm element 80, but the configuration of the second arm element 80 is otherwise the same as shown in the first embodiment. In particular, the second fixed part 82 is provided with the hole 82a; the base end part 83 extends from the second fixed part 82 in the axial direction of the small-diameter roller 40; the support part 84 for the large-diameter roller is provided at the distal end of the base end part 83; the support part 81 for the small-diameter roller is provided at one end of the second arm element 80; and the connecting part 85, which connects the support part 84 for the large-diameter roller and the support part 81 for the small-diameter roller, is formed.In the same way as in the first embodiment, the connecting part 85 extends mainly in the direction of the axis of rotation RL2 of the corresponding large-diameter roller 50, as seen from the direction of extension of the axis of rotation RL.

[0144] Furthermore, as shown in the first embodiment, the support part 71 for the small-diameter roller is provided with the hole 71a into which the bolt B1 for the small-diameter roller is screwed, and the support part 74 for the large-diameter roller is provided with the hole 74a through which the bolt B2 for the large-diameter roller passes. As shown in the first embodiment, the support part 81 is provided with the hole 81a through which the bolt B1 of the small diameter passes, and the support part 84 of the large diameter is provided with the hole 84a into which the bolt B2 of the large diameter is screwed.

[0145] In this modified example, the large-diameter roller 50 is supported by the support 60 as the first roller, and the small-diameter roller 40 is supported by the support 60 as the second roller.

[0146] In this modified example as well, the large-diameter roller 50 is not supported by a single element, but by the first arm element 70 and the second arm element 80. The small-diameter roller 40 is supported on one side by the second arm element 80 and on the other side by the first arm element 70.

[0147] In contrast to the situation where the small-diameter roller 40 and the large-diameter roller 50 are supported by a single element, a force exerted on the small-diameter roller 40 upon contact with a road surface is more likely to be transmitted to the adjacent large-diameter rollers 50, and vice versa. Furthermore, this modified example achieves the other effects of the first embodiment.

[0148] In the first embodiment, as in Fig. 1 and Fig. As shown in Figure 13, a part 76 of an end of the first arm element 70 is arranged between an end surface 41b in the axial direction of the core element 41 of the roller 40 with small diameter and an end surface 51e in the axial direction of the outer circumferential part 51b of the core element 51 of the roller 50 with large diameter.

[0149] Cables, such as power cables and LAN cables, and similar linear objects may be present on the floor surface of an office, a hallway in an interior space, a passageway in an interior space, or similar areas. In particular, such cables and linear objects are often found under a desk, etc.

[0150] The in Fig. The electric mobility vehicle 100 shown is highly likely to be driving on a floor surface where cables and linear objects, as described above, are present. In particular, if the driver, while working at a desk, moves the omnidirectional wheels 1, which are either the front or rear wheels, the omnidirectional wheels 1 may come into contact with a cable or a linear object.

[0151] Since one part 76 of the first arm element 70 is positioned between the end face 41b of the core element 41 of the small-diameter roller 40 and the end face 51e of the core element 51 of the large-diameter roller 50, it is less likely that a cable or linear object will become trapped between the small-diameter roller 40 and the large-diameter roller 50. If a cable or linear object does become trapped, it will wrap around either the small-diameter roller 40 or the large-diameter roller 50. The above configuration is useful for preventing or reducing such a problem.

[0152] As in Fig. As shown in Figure 13, a part 86 of an end of the second arm element 80 is also arranged between the end surface 41b of the core element 41 of the roller 40 with small diameter and the end surface 51e of the outer circumferential part 51b of the core element 51 of the roller 50 with large diameter.

[0153] In each of the above embodiments, as in Fig. As shown in Figure 22, a central section 83a of an inner surface of the base-end part 83 of the second arm element 80 curves in the wheel width direction towards the inside in the wheel radial direction. In this embodiment, the wheel radial direction and the radial direction of the hub elements 20, 30 coincide. In this embodiment, the entire inner surface curves towards the inside in the wheel radial direction. Furthermore, in this embodiment, as shown in Fig. 9 shown, the central section 83a as described above along the entire base end-side part 83 in its longitudinal direction.

[0154] Part of the inner surface faces the inner circumferential surface of the outer circumferential part 51b of the large-diameter roller 50. On the inner surface, the distance between the central section 83a in the wheel width direction and the inner circumferential surface of the outer circumferential part 51b of the large-diameter roller 50, and the distance between an end section 83b in the wheel width direction and the inner circumferential surface of the outer circumferential part 51b, is not greater than 1 mm. A central section 73a of the base end section 73 of the first arm element 70 also curves in the same way as the central section 83a of the base end section 83 of the second arm element 80, and the distance between the inner surface of the base end section 73 and the inner circumferential surface of the outer circumferential part 51b of the large-diameter roller 50 is also the same.

[0155] Thus, even if the basic end page part 73 or 83 is in the position of the in Fig.If the large-diameter roller breaks in the section shown in Figure 22, or at a position closer to the support part 74 or 84, the inner circumferential surface of the outer circumferential part 51b of the large-diameter roller 50 contacts the inner surface of the base end part 73 or 83, thus preventing the large-diameter roller 50 from moving in the wheel radial direction and from moving in the wheel circumferential direction relative to the first arm element 70 and the second arm element 80. For example, even after a break of the base end parts 73, 83 under an unexpected load, the surfaces resulting from the break are opposite each other. This prevents the large-diameter roller 50 from moving in the wheel circumferential direction relative to the first arm element 70 and the second arm element 80.While this effect is to be expected if the distance between the central section 83a in the wheel width direction and the inner circumferential surface of the outer circumferential part 51b of the large diameter roller 50 is not greater than 2 mm, the distance is preferably not greater than 1.5 mm.

[0156] Sections of the base end pieces 73, 83 on the side of the support pieces 74, 84 of the large-diameter roller are arranged within the recesses 55 of the large-diameter roller 50. In this way, the large-diameter rollers 50 remain attached to the base end pieces 73, 83, thus preventing them from detaching from the omnidirectional wheel. In this case, even if the base end pieces 73, 83 break under an unexpected load, travel with the omnidirectional wheel is still possible.

[0157] The fact that sections of the large-diameter rollers 50 are arranged between the hub elements 20, 30, as shown in this embodiment, also contributes to preventing the large-diameter rollers 50 from detaching from the omnidirectional wheel.

[0158] Sections of the base end parts 73, 83 on the side of the support parts 74, 84 of the large-diameter roller are arranged within the recesses 55 of the large-diameter rollers 50, with the weakest sections of the base end parts 73, 83 being located within the recesses 55. In this embodiment, the weakest section is a section with the smallest cross-sectional area in the base end part 73 or 83. This configuration is advantageous to prevent the large-diameter rollers 50 from detaching from the omnidirectional wheel if the base end parts 73, 83 break under an unexpected load. [List of reference symbols] 1 Omnidirectional wheel 10-axis 20, 30 Hub part (rotating part) 40 small diameter rolls (first roll) 40a Hole 41 Core element 43 wave 50 large diameter rolls (second roll) 50b Plug element 51 Core element 53 wave 60 support 61 Fixed part 70 First arm element, first arm 71 Support part for small diameter roller 72 First fixed part 73 Basic end page section 73a Middle section 73b Final section 74 Support part for large diameter roller 75 Connecting part 80 Second arm element, second arm 81 Support part for small diameter roller 82 Second fixed part 83 Basic end page section 83a Middle section 83b Final section 84 Support part for large diameter roller 85 Connecting part 90 Beveled section (incision section) 91 First flat surface part 92 Second flat surface part 93 Curved surface part 94 screw element 95 Plug element 96 holes 97 Fastening element RL, RL1, RL2 Rotation axis

Claims

[1] Omnidirectional wheel (1) whose outer circumferential surface is formed with a plurality of rollers (40, 50) and which rotates about a rotation axis (RL, RL1, RL2) of an axis (10), wherein the omnidirectional wheel (1) comprises: a rotating part (20, 30) that rotates around the axis of rotation (RL, RL1, RL2) of the axis (10); and a plurality of supports (60) arranged in a circumferential direction of the rotating part (20, 30), each of which is mounted on the rotating part (20, 30) to support the plurality of rollers (40, 50) on the rotating part (20, 30), wherein the majority of rollers (40, 50) includes a majority of first rollers (40) and a majority of second rollers (50) with a different outer diameter than the first rollers (40), the first rollers (40) and the second rollers (50) alternate in the circumferential direction, Each of the supports (60) has a first arm element (70) that supports one end side in an axial direction of a corresponding first roller (40) that corresponds to one of the plurality of the first rollers (40), and a second arm element (80) that supports the other end side in the axial direction of the corresponding first roller (40), and a corresponding second roller (50), which corresponds to one of the plurality of second rollers (50), is supported by the first arm element (70) of one of two supports (60) that are adjacent to each other in the circumferential direction, and the second arm element (80) of the other of the two supports (60), wherein one end side in the axial direction of the corresponding first roller (40) is supported by an end side of the first arm element (70), wherein the other end side of the first arm element (70) is mounted on the rotating part (20, 30), and the other end side in the axial direction of the corresponding first roller (40) is supported by an end side of the second arm element (80), the other end side of the second arm element (80) being mounted on the rotating part (20, 30). [2] Omnidirectional wheel (1) according to claim 1, wherein one end side and the other end side are attached in the axial direction of the corresponding first roller (40) to the first arm element (70) and the second arm element (80) by a fastening element extending in the axial direction of the corresponding first roller (40). [3] Omnidirectional wheel (1) according to claim 1 or 2, wherein the corresponding second roller (50) is attached to the first arm element (70) and the second arm element (80) by a fastening element extending in the axial direction of the corresponding second roller (50). [4] Omnidirectional wheel (1) according to any one of claims 1 to 3, wherein the first roller (40) is a roller (40) with a small diameter, and the second roller (50) is a roller (50) with a large diameter, which has a larger outer diameter than the first roller (40). [5] Omnidirectional wheel (1) according to claim 4, wherein in the first arm element (70) a support part (74) for a large-diameter roller (50), which carries the corresponding second roller (50), is arranged on an inner side in a radial direction of the rotating part (20, 30) relative to a support part (81) for a small-diameter roller (40), which carries an end side in the axial direction of the first roller (40), the first arm element (70) has a connecting part (75, 85) that connects the support part (74) for a large diameter roller (50) and the support part (81) for a small diameter roller (40), and The connecting part (75, 85), when viewed from a direction of extension of the axis of rotation (RL, RL1, RL2) of the axis (10), extends in a direction of an axis of rotation (RL, RL1, RL2) of the corresponding second roller (50). [6] Omnidirectional wheel (1) according to claim 5, wherein in the second arm element (80) a support part (74) for a large-diameter roller (50), which carries the corresponding second roller (50), is arranged on the inside in the radial direction relative to a support part (81) for a small-diameter roller (40), which carries the other end side in the axial direction of the first roller (40), the second arm element (80) has a connecting part (75, 85) that connects the support part (74) for a large diameter roller (50) and the support part (81) for a small diameter roller (40), and the connecting part (75, 85) of the second arm element (80), when viewed from a direction of extension of the axis of rotation (RL, RL1, RL2) of the axis (10), extends in a direction of the axis of rotation (RL, RL1, RL2) of the corresponding second roller (50). [7] Omnidirectional wheel (1) according to claim 5, wherein a direction of extension of the connecting part (75, 85) of the first arm element (70) and a direction of the axis of rotation (RL, RL1, RL2) of the corresponding second roller (50) form an angle of not more than 20°. [8] Omnidirectional wheel (1) according to claim 1, wherein the other end side of the first arm element (70) and the other end side of the second arm element (80) overlap each other in a predetermined direction along the axis of rotation (RL, RL1, RL2) of the axis (10). [9] Omnidirectional wheel (1) according to claim 8, wherein a first stationary part (72) which is attached to the rotating part (20, 30) is formed on the other end side of the first arm element (70), a second fixed part (82) which is attached to the rotating part (20, 30) is formed on the other end side of the second arm element (80), the first fixed part (72) is formed at a position that is offset to one side in the predetermined direction relative to the center of the first arm element (70) in a direction along the axis of rotation (RL, RL1, RL2) of the axis (10); and the second fixed part (82) is formed at a position which is offset to the other side in the predetermined direction relative to the center of the second arm element (80) in a direction along the axis of rotation (RL, RL1, RL2) of the axis (10). [10] Omnidirectional wheel (1) according to any one of claims 1 to 9, wherein at least one roller (40, 50) of the plurality of rollers (40, 50) has a hole (40a) extending from an outer circumferential surface of the roller (40, 50) to an inner circumferential surface of the roller (40, 50). [11] Omnidirectional wheel (1) according to claim 10, wherein the hole (40a) is closed by a plug element (95) that closes the hole (40a). [12] Omnidirectional wheel (1) according to claim 10 or 11, wherein, at least one role (40, 50) is the corresponding first role (40), one end side in the axial direction and the other end side in the axial direction of the corresponding first roller (40) are mounted on the support (60) by a bolt extending in the axial direction of the corresponding first roller (40), and an outer circumferential surface of the bolt has an engagement section (90) which is formed at an axial position corresponding to the hole (40a). [13] Omnidirectional wheel (1) according to claim 12, wherein, as the engagement section (90), the outer circumferential surface of the bolt comprises a first flat surface part (91), a second flat surface part (92) which is arranged at a different position than the first flat surface part (91) in a circumferential direction of the outer circumferential surface of the bolt, and a curved surface part (93) which connects the first flat surface part (91) and the second flat surface part (92). [14] Omnidirectional wheel (1) according to claim 10 or 11, wherein at least one role (40, 50) is the corresponding first role (40), one end side in the axial direction and the other end side in the axial direction of the corresponding first roller (40) are attached to the support (60) by a bolt extending in the axial direction of the corresponding first roller (40), the hole (40a) is one into which a screw element (94) can be engaged, and the bolt has an engagement section (90) at an axial position corresponding to the hole (40a) which engages with the screw element (94). [15] Omnidirectional wheel (1) according to any one of claims 4 to 9, wherein a part of an end side in the axial direction of the corresponding first roller (40) is arranged within a recess formed at one end in the axial direction of the corresponding second roller (50).

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