Drive disk

Abstract

A drive disk is provided, which is configured to rotate a main wheel by applying frictional force to the main wheel. Each drive disk in the drive disks includes a base portion and a plurality of rollers. The base portion includes a first plate-shaped metal member and a second plate-shaped metal member. The first plate-shaped metal member includes a first central portion and a plurality of first arm portions. The second plate-shaped metal member includes a second central portion and a plurality of second arm portions. Each of the plurality of rollers has a first end and a second end. Each of the plurality of first arm portions includes a first support portion and a second support portion. Each of the plurality of second arm portions includes a third support portion and a fourth support portion. The first support portion and the second support portion are inclined with respect to each other. The third support portion and the fourth support portion are inclined with respect to each other.

Description

Technical Field

[0001] The present invention relates to a drive disk for a friction drive unit. Background Art

[0002] There is a known friction drive unit used as a drive device for an inverted pendulum vehicle (for example, JP2011 - 63214A). The friction drive unit includes: a frame, a pair of drive disks rotatably supported by the frame, an annular main wheel disposed between the pair of drive disks, and a pair of actuators configured to independently drive each of the drive disks. The drive disk has a disk-shaped base portion rotatable relative to the frame, and a plurality of drive rollers rotatably supported by an outer peripheral portion of the base portion in contact with the main wheel. The drive rollers are provided at rotationally symmetric positions about the rotation axis of the base portion. The main wheel can rotate about a central axis and an annular axis. The friction drive unit controls the rotation of the main wheel about the central axis and the annular axis by controlling the rotation direction and rotation amount of the pair of drive disks, thereby moving the inverted pendulum vehicle in various directions, including: forward direction, backward direction, left direction, and right direction.

[0003] Each drive disk according to JP2011 - 63214A has a slot for accommodating a drive roller, a bearing hole formed in a side wall defining each slot, and a roller shaft inserted in each bearing hole in an axial direction of each bearing hole to rotatably support each drive roller.

[0004] Each drive disk according to JP2011 - 63214A has a bearing wall for rotatably supporting a drive roller by the base portion, and a slot formed between the bearing walls. Since the bearing wall and the slot are provided in different directions, it is difficult to form these components, and thus the cost increases. One possible manufacturing method is to prepare the bearing wall as a separate member and then assemble the member to the base portion. However, this manufacturing method may increase the number of operations due to assembling a large number of bearing walls to the base portion. Summary of the Invention

[0005] In view of such problems of the prior art, a main object of the present invention is to provide a drive disk that can be easily manufactured.

[0006] To achieve this object, an aspect of the present invention provides a drive disk 4, which is disposed on both sides of an annular main wheel 5 and is configured to rotate the main wheel about a central axis and an annular axis by applying frictional force to the main wheel. Each drive disk in the drive disks includes: a disk-shaped base 20 rotatably supported by a frame 3; and a plurality of rollers 21, which are rotatably supported by an outer peripheral portion of the base, are inclined with respect to each other, and are in contact with the main wheel. Among them, the base includes a first plate-shaped metal member 47 and a second plate-shaped metal member 48. The first plate-shaped metal member includes a first central portion 51 and a plurality of first arm portions 52 radially extending outward from the first central portion. The second plate-shaped metal member includes a second central portion 61 and a plurality of second arm portions 62 radially extending outward from the second central portion. The first central portion and the second central portion are coaxially arranged with each other. Each of the plurality of rollers has a first end 43A and a second end 43B along the rotation axis direction of the roller. Each of the plurality of first arm portions includes a first support portion 71 and a second support portion 72. The second support portion is arranged inside the first support portion in the radial direction of the base. Each of the plurality of second arm portions includes a third support portion 73 and a fourth support portion 74. The fourth support portion is arranged outside the third support portion in the radial direction of the base. The first end of one of two adjacent rollers is supported by the first support portion, and the second end of the one roller is supported by the third support portion. The first end of the other roller among two adjacent rollers is supported by the fourth support portion, and the second end of the other roller is supported by the second support portion. The first support portion and the second support portion are inclined with respect to each other, and there is a first bending portion 54E between the first support portion and the second support portion. The third support portion and the fourth support portion are inclined with respect to each other, and there is a second bending portion 67E between the third support portion and the fourth support portion.

[0007] According to this aspect, the base rotatably supporting the plurality of rollers can be formed by two plate-shaped metal members, so that the drive disk can be easily manufactured.

[0008] In the above aspect, preferably, the first support portion and the third support portion are arranged parallel to each other, and the second support portion and the fourth support portion are arranged parallel to each other.

[0009] According to this aspect, the first arm portion and the second arm portion can stably support each roller.

[0010] In the above aspect, preferably, in the circumferential direction of the first plate-shaped metal member and the second plate-shaped metal member, the tip ends of each of the plurality of second arm portions are arranged between the tip ends of two adjacent first arm portions.

[0011] According to this aspect, the first arm portions and the second arm portions are alternately provided in the circumferential direction of the first plate-like metal member and the second plate-like metal member. In addition, a plurality of rollers may be provided in the corresponding spaces between the first arm portions and the second arm portions.

[0012] In the above aspect, preferably, the tips of each of the plurality of first arm portions and the tips of each of the plurality of second arm portions are provided on a virtual plane perpendicular to the rotation axis of the base.

[0013] According to this aspect, the first arm portions and the second arm portions are alternately provided in the circumferential direction of the base.

[0014] In the above aspect, preferably, the tip of each of the plurality of first arm portions extends outward in the radial direction of the base, and the tip of each of the plurality of second arm portions extends inward in the radial direction of the base.

[0015] According to this aspect, the first arm portions and the second arm portions can be alternately provided in the circumferential direction of the base without interfering with each other.

[0016] Therefore, according to the above aspect, a driving disk that can be easily manufactured can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of an inverted pendulum carrier including a driving disk according to an embodiment;

[0018] Figure 2 is a side view of the friction drive unit;

[0019] Figure 3 is along Figure 2 sectional view taken along line III-III;

[0020] Figure 4 is a perspective view of a driving disk including a driving roller;

[0021] Figure 5 is a perspective view of the first plate-like metal member;

[0022] Figure 6 is a perspective view of the second plate-like metal member;

[0023] Figure 7 is a perspective view of the roller accommodating portion of the driving disk without the driving roller; and

[0024] Figure 8 is a perspective view showing the roller accommodating portion of the driving disk. DETAILED DESCRIPTION

[0025] Next, with reference to the accompanying drawings, an embodiment of the drive disk according to the present invention will be described. The drive disk is used for a friction drive unit. The friction drive unit is used, for example, for an inverted pendulum vehicle.

[0026] As Figures 1 to 3 shown, the inverted pendulum vehicle 1 includes a friction drive unit 2. The friction drive unit 2 includes: a frame 3, a pair of drive disks 4 (left drive disk and right drive disk 4) rotatably supported by the frame 3, an annular main wheel 5 disposed between the pair of drive disks 4, and a pair of actuators 6 configured to rotate the pair of drive disks 4 independently.

[0027] As Figure 1 shown, the frame 3 includes: an upper frame 11 formed in a substantially parallelepiped shape, a lower left frame and a lower right frame 12 extending downward from the left lower end and the right lower end of the upper frame 11 respectively, a lower left plate and a lower right plate 13 respectively connected to the lower frame 12, and a support shaft 14 extending between the lower left frame and the lower right frame 12 (see Figure 3 ). A saddle 16 for supporting the occupant's buttocks is attached to the upper part of the upper frame 11. A left footrest and a right footrest 17 for supporting the occupant's soles are attached to the lower ends of the lower plates 13.

[0028] As Figure 3 shown, the support shaft 14 extends in the lateral direction and is connected to the lower left frame and the lower right frame 12. The left end of the support shaft 14 passes through the lower left frame 12, and the right end of the support shaft 14 passes through the lower right frame 12. A bolt head 14A is provided at the base end of the support shaft 14, and the support shaft 14 contacts one of the lower frames 12 at the bolt head 14A. A nut 18 is attached to the tip end of the support shaft 14 to fix the support shaft 14 to the other lower frame 12.

[0029] The drive disks 4 are respectively disposed on both sides of the annular main wheel 5, and are configured to rotate the main wheel 5 about the central axis and rotate the main wheel 5 (more specifically, the outer peripheral portion of the main wheel 5) about the annular axis by applying frictional force to the main wheel 5. Each drive disk 4 includes: a disk-shaped base 20 rotatably supported by the frame 3; and a plurality of drive rollers 21 (a plurality of rollers) rotatably supported by the outer peripheral portion of the base 20, inclined with respect to each other, and in contact with the main wheel 5.

[0030] In the present embodiment, the left drive disk and the right drive disk 4 are rotatably supported by a support shaft 14 and are disposed between the lower left frame and the lower right frame 12. Each of the left drive disk and the right drive disk 4 is formed in a disk shape and has a bearing hole 23 (through hole) at the center of the drive disk. The support shaft 14 passes through the bearing holes 23 of each of the left drive disk and the right drive disk 4. The left drive disk and the right drive disk 4 are supported by the support shaft 14 so as to rotate about an axis X1 (central axis). A bearing 24 such as a ball bearing is attached to the bearing hole 23, and each of the left drive disk and the right drive disk 4 is supported by the support shaft 14 via the bearing 24.

[0031] Each of the left drive disk and the right drive disk 4 has an opposing surface. The opposing surface of the left drive disk 4 faces the opposing surface of the right drive disk 4. A driven pulley 31 is provided on the opposing surface of each of the left drive disk and the right drive disk 4. The driven pulley 31 is provided coaxially with each of the left drive disk and the right drive disk 4. As Figure 1 shown, the upper frame 11 is provided with a right actuator 6 for driving the right drive disk 4 and a left actuator 6 for driving the left drive disk 4. Each actuator 6 is composed of, for example, an electric motor. A drive pulley 32 is provided on the output shaft of each actuator 6. The drive pulley 32 and the driven pulley 31 corresponding to each other in the lateral direction are connected by a belt 33. The left actuator and the right actuator 6 can rotate independently of each other, so that the left drive disk and the right drive disk 4 rotate independently.

[0032] As Figures 1 to 3 shown, the main wheel 5 has an annular shape and is disposed between the pair of drive disks 4 so as to be coaxial with the pair of drive disks 4. The main wheel 5 is in contact with the plurality of drive rollers 21 and can rotate about the central axis and the annular axis. In the present embodiment, the main wheel 5 includes: an annular core member 35; and a plurality of driven rollers 36 rotatably supported by the core member 35. The plurality of driven rollers 36 are provided at equal intervals in the circumferential direction of the core member 35. Each driven roller 36 is rotatably supported by the core member 35 about an axis X3 (annular axis) of the annular core member 35. More specifically, each driven roller 36 can rotate about a tangent line of the core member 35 at a corresponding position with respect to the core member 35. When an external force is applied, each driven roller 36 rotates with respect to the core member 35.

[0033] The main wheel 5 is disposed along the outer peripheral portions of the left drive disk and the right drive disk 4, and contacts the plurality of drive rollers 21 of the left drive disk and the right drive disk 4. The drive rollers 21 of the left drive disk and the right drive disk 4 contact the inner peripheral portion of the main wheel 5 and hold the main wheel 5 from either lateral side of the main wheel 5. Further, the drive rollers 21 of the left drive disk and the right drive disk 4 contact the inner peripheral portion of the main wheel 5, thereby suppressing the displacement of the drive disk 4 in the radial direction about the axis X1. Accordingly, the main wheel 5 is supported by the left drive disk and the right drive disk 4, and the central axis of the main wheel 5 (core member 35) is disposed coaxially with the axis X1 of the left drive disk and the right drive disk 4. The plurality of driven rollers 36 of the main wheel 5 contact the plurality of drive rollers 21 of the left drive disk and the right drive disk 4.

[0034] As Figure 1 shown, the left front end and the right front end of the tail wheel arm 38 are supported by the lower left plate and the lower right plate 13 such that the tail wheel arm 38 can rotate about a rotation axis extending in the lateral direction. The rotation axis of the tail wheel arm 38 may coincide with the axis X1 of the drive disk 4. The tail wheel arm 38 extends rearward from the bifurcated front end of the tail wheel arm. A tail wheel 39 is provided at the rear end of the tail wheel arm 38. The tail wheel 39 is, for example, a caster wheel and is supported by the rear end of the tail wheel arm 38 so as to rotate about an axis extending in the front-rear direction. The tail wheel 39 is rotated by a tail wheel motor 40 which is an electric motor provided at the rear end of the tail wheel arm 38.

[0035] When the left drive disk and the right drive disk 4 rotate in the same direction at the same rotational speed, the main wheel 5 rotates together with the left drive disk and the right drive disk 4. That is, the main wheel 5 rotates about its own rotation axis which coincides with the axis X1, thereby causing the inverted pendulum vehicle 1 to move forward or backward. At this time, the drive rollers 21 of the drive disk 4 and the driven rollers 36 of the main wheel 5 do not rotate relative to the core member 35.

[0036] When the rotational speeds of the left drive disk and the right drive disk 4 are different, a component force is applied from the drive rollers 21 of the left drive disk and the right drive disk 4 to the driven rollers 36 of the main wheel 5. The component force is a force in a direction perpendicular to the force in the circumferential direction (tangential direction) caused by the rotation of the left drive disk and the right drive disk 4. The axis of each drive roller 21 is inclined with respect to the circumferential direction of the drive roller 21 (left drive disk and right drive disk 4), and thus, a component force is generated due to the different rotational speeds of the left drive disk and the right drive disk 4. Due to this component force, the drive rollers 21 rotate relative to the base 20, and the driven rollers 36 rotate relative to the core member 35. Accordingly, the main wheel 5 generates a driving force in the direction along the rotation axis (i.e., in the lateral direction of the inverted pendulum vehicle 1). Accordingly, the inverted pendulum vehicle 1 rotates left or right about the tail wheel 39.

[0037] Next, with reference to Figures 4 to 8Describe in detail one of the pair of drive disks 4 (hereinafter simply referred to as "drive disk 4"). Regarding the two directions along the axis X1 of the drive disk 4, one direction towards the main wheel 5 is defined as the "first direction", and the other direction opposite to the first direction is defined as the "second direction".

[0038] As Figure 8 shown, each drive roller 21 includes a shaft 43 and a roller body 44. The roller body 44 is rotatably provided at the center of the shaft 43 and has a larger diameter than the shaft 43. Regarding the drive disk 4, the drive rollers 21 are arranged at rotationally symmetric positions around the axis X1 of the drive disk 4. The drive rollers 21 are arranged at equal intervals in the circumferential direction of the drive disk 4 in the outer peripheral portion of the drive disk 4. The shaft 43 of each drive roller 21 is inclined with respect to the circumferential direction (tangential direction) of the drive disk 4 and is also inclined with respect to a plane perpendicular to the axis X1 of the drive disk 4. A part of each drive roller 21 protrudes in the first direction with respect to the base 20. The end of the shaft 43 on one side in the circumferential direction of the drive disk 4 is defined as the first end 43A, and the end of the shaft 43 on the side opposite to the said side in the circumferential direction of the drive disk is defined as the second end 43B.

[0039] As Figure 4 shown, the base 20 of the drive disk 4 includes a first plate-shaped metal member 47 and a second plate-shaped metal member 48. Each of the first plate-shaped metal member 47 and the second plate-shaped metal member 48 is formed by cutting, drilling, and bending a flat metal plate. Each of the first plate-shaped metal member 47 and the second plate-shaped metal member 48 can be made of alloy steel such as stainless steel, carbon steel, or non-ferrous metal materials such as aluminum.

[0040] As Figure 5 shown, the first plate-shaped metal member 47 includes: a first central portion 51; and a plurality of first arm portions 52 radially extending outward from the first central portion 51. The first central portion 51 is formed in a disk shape. The first central portion 51 has a first surface 51A facing the first direction and a second surface 51B facing the second direction. The axis of the first central portion 51 coincides with the axis X1 of the drive disk 4 and the axis of the base 20.

[0041] A circular first hole 51C penetrating from the first surface 51A to the second surface 51B is formed at the center of the first central portion 51. In addition, a plurality of first bolt holes 51D are provided around the first hole 51C in the first central portion 51. The first hole 51C is coaxially arranged with the axis X1 of the drive disk 4.

[0042] The plurality of first arm portions 52 are formed to be rotationally symmetric with respect to the axis X1 of the drive disk 4. The plurality of first arm portions 52 are provided at equal intervals around the axis X1 of the drive disk 4. Each of the first arm portions 52 includes: a first arm base end 53 that extends radially outward from a first central portion 51; and a first arm tip end 54 that extends from the tip end of the first arm base end 53. The first arm tip end 54 extends in a direction different from the direction in which the first arm base end 53 extends.

[0043] The first arm base end 53 is provided in the same plane as the first central portion 51. When viewed in the direction along the axis X1 of the drive disk 4, the extending direction of the first arm base end 53 may form a predetermined angle with the radial direction of the first central portion 51 (i.e., the extending direction of the first arm base end 53 may be inclined with respect to the radial direction of the first central portion 51). The first arm base end 53 is formed in a flat plate shape. The first arm base end 53 includes: a first surface 53A provided in the same plane as the first surface 51A of the first central portion 51; and a second surface 53B provided in the same plane as the second surface 51B of the first central portion 51.

[0044] A first bending portion 56 that linearly extends is formed at the boundary between the first arm tip end 54 and the first arm base end 53. At the first bending portion 56, the first arm tip end 54 bends from the first arm base end 53 in a second direction such that an acute angle is formed between the first arm base end 53 and the first arm tip end 54.

[0045] The first arm tip end 54 extends radially outward from the tip end of the first arm base end 53 along the radial direction of the drive disk 4. In addition, when viewed in the direction along the axis X1 of the drive disk 4, the first arm tip end 54 extends in a direction perpendicular to the first arm base end 53. In addition, when viewed from the first surface 51A side of the first central portion 51, the first arm tip end 54 extends from the first arm base end 53 in the clockwise direction around the axis X1 of the drive disk 4.

[0046] The first arm tip end 54 is formed in a flat plate shape. The first surface 54A of the first arm tip end 54 faces the second direction and faces one side in the circumferential direction around the axis X1 of the drive disk 4. The second surface 54B of the first arm tip end 54 faces the first direction and faces the other side in the circumferential direction around the axis X1 of the drive disk 4.

[0047] The first surface 54A of the first arm tip 54 is connected to the first surface 53A of the first arm base end 53 via the curved surface of the first bending portion 56. Similarly, the second surface 54B of the first arm tip 54 is connected to the second surface 53B of the first arm base end 53 via the curved surface of the first bending portion 56. The first arm tip 54 includes a first side edge 54C and a second side edge 54D extending in the longitudinal direction of the first arm tip 54. The first side edge 54C is disposed on the first direction side with respect to the second side edge 54D.

[0048] As Figure 3 and Figure 4 shown, the second plate-like metal member 48 is disposed on the second direction side with respect to the first plate-like metal member 47. As Figure 6 shown, the second plate-like metal member 48 includes: a second central portion 61; and a plurality of second arm portions 62 radially extending outward from the second central portion 61. The second central portion 61 is formed in a disc shape. The second central portion 61 has a first surface 61A facing the first direction and a second surface 61B facing the second direction. The axis of the second central portion 61 is coaxially disposed with the axis X1 of the drive disc 4. The first central portion 51 and the second central portion 61 are coaxially disposed with each other. The radius of the second central portion 61 is larger than the radius of the first central portion 51.

[0049] A circular second hole 61C penetrating from the first surface 61A to the second surface 61B is formed at the center of the second central portion 61. Further, a plurality of second bolt holes 61D are provided around the second hole 61C in the second central portion 61. The second hole 61C is coaxially disposed with the axis X1 of the drive disc 4.

[0050] As Figure 3 shown, the first central portion 51 and the second central portion 61 are fastened via a spacer 26 by a plurality of bolts 64 and nuts 65. Each bolt 64 passes through the first bolt hole 51D, a bolt hole (not shown) formed in the spacer 26, and the second bolt hole 61D. A bearing hole 23 is provided in the central portion of the spacer 26 and is formed coaxially with the axis X1 of the drive disc 4.

[0051] As Figure 6 shown, the plurality of second arm portions 62 are formed to be rotationally symmetric with each other about the axis X1 of the drive disc 4. The plurality of second arm portions 62 are provided at equal intervals around the axis X1 of the drive disc 4. Each second arm portion 62 includes: a second arm base end 66 radially extending outward from the second central portion 61; and a second arm tip 67 extending from the tip of the second arm base end 66. The second arm tip 67 extends in a direction different from the direction in which the second arm base end 66 extends.

[0052] The proximal end 66 of the second arm is disposed in the same plane as the second central portion 61. When viewed in the direction along the axis X1 of the drive disk 4, the extending direction of the proximal end 66 of the second arm may form a predetermined angle with the radial direction of the second central portion 61 (i.e., the extending direction of the proximal end 66 of the second arm may be inclined with respect to the radial direction of the second central portion 61). The proximal end 66 of the second arm is formed in a flat plate shape. The proximal end 66 of the second arm includes: a first surface 66A disposed in the same plane as the first surface 61A of the second central portion 61; and a second surface 66B disposed in the same plane as the second surface 61B of the second central portion 61.

[0053] A second bending portion 68 extending linearly is formed at the boundary between the distal end 67 of the second arm and the proximal end 66 of the second arm. At the second bending portion 68, the distal end 67 of the second arm bends from the proximal end 66 of the second arm in the first direction such that an obtuse angle is formed between the proximal end 66 of the second arm and the distal end 67 of the second arm.

[0054] The distal end 67 of the second arm extends inward in the radial direction of the drive disk 4 from the distal end of the proximal end 66 of the second arm. Further, when viewed from the first surface 61A side of the second central portion 61, the distal end 67 of the second arm extends from the proximal end 66 of the second arm in the counterclockwise direction around the axis X1 of the drive disk 4.

[0055] The distal end 67 of the second arm is formed in a flat plate shape. The first surface 67A of the distal end 67 of the second arm faces the first direction and faces one side in the circumferential direction around the axis X1 of the drive disk 4. The second surface 67B of the distal end 67 of the second arm faces the second direction and faces the other side in the circumferential direction around the axis X1 of the drive disk 4.

[0056] The first surface 67A of the distal end 67 of the second arm is connected to the first surface 66A of the proximal end 66 of the second arm via the curved surface of the second bending portion 68. Similarly, the second surface 67B of the distal end 67 of the second arm is connected to the second surface 66B of the proximal end 66 of the second arm via the curved surface of the second bending portion 68. The distal end 67 of the second arm includes a third side edge 67C and a fourth side edge 67D extending in the longitudinal direction of the distal end 67 of the second arm. The third side edge 67C is disposed on the first direction side with respect to the fourth side edge 67D.

[0057] As Figure 4 、 Figure 7 And Figure 8As shown, in the circumferential direction of the base 20, one of the second arm tips 67 is disposed between two adjacent first arm tips 54. Similarly, in the circumferential direction of the base 20, one of the first arm tips 54 is disposed between two adjacent second arm tips 67. That is, the first arm tips 54 and the second arm tips 67 are alternately disposed in the circumferential direction of the base 20 about the axis X1. Each of the first arm tips 54 and each of the second arm tips 67 are disposed on a virtual plane perpendicular to the rotation axis of the base 20.

[0058] The drive disk 4 includes a plurality of roller receiving portions 69 that receive the roller bodies 44 of the drive rollers 21. Each of the roller receiving portions 69 is defined by a first arm tip 54 and a second arm tip 67 adjacent to each other. The roller receiving portion 69 includes: a first roller receiving portion 69A defined by the second surface 54B of the first arm tip 54 and the second surface 67B of the second arm tip 67, respectively; and a second roller receiving portion 69B defined by the first surface 54A of the first arm tip 54 and the first surface 67A of the second arm tip 67, respectively. The first roller receiving portion 69A and the second roller receiving portion 69B are alternately disposed in the circumferential direction of the base 20. Each of the roller receiving portions 69 opens toward the first direction.

[0059] As Figure 4 and Figure 5 shown, each of the first arm portions 52 includes a first support portion 71 and a second support portion 72. The second support portion 72 is disposed inside the first support portion 71 in the radial direction of the base 20. The first support portion 71 and the second support portion 72 are disposed in the first arm tip 54, and the second support portion 72 is disposed closer to the base end of the first arm tip 54 than the first support portion 71.

[0060] As Figure 4 and Figure 6 shown, each of the second arm portions 62 includes a third support portion 73 and a fourth support portion 74. The fourth support portion 74 is disposed outside the third support portion 73 in the radial direction of the base 20. The third support portion 73 and the fourth support portion 74 are disposed in the second arm tip 67, and the fourth support portion 74 is disposed closer to the base end of the second arm tip 67 than the third support portion 73.

[0061] As Figure 4 and Figure 8As shown, one first end 43A of one of two adjacent drive rollers 21 (i.e., two drive rollers 21 adjacent to each other) is supported by a first support portion 71, and a second end 43B of said one drive roller is supported by a third support portion 73. Further, one first end 43A of the other of the two adjacent drive rollers 21 is supported by a fourth support portion 74, and a second end 43B of said other drive roller is supported by a second support portion 72. That is, each first arm portion 52 and each second arm portion 62 support one first end 43A of one of two adjacent drive rollers 21 and a second end 43B of the other of the two adjacent drive rollers 21.

[0062] As Figures 5 to 7 shown, the first support portion 71 to the fourth support portion 74 include through holes that accommodate shafts 43 of respective drive rollers 21 and penetrate the first arm tip 54 or the second arm tip 67 in the thickness direction of the first arm tip or the second arm tip.

[0063] As Figure 8 shown, the first arm tip 54 includes a first bending portion 54E between the first support portion 71 and the second support portion 72. Thus, the first bending portion 54E divides the first arm tip 54 into a first portion 54F provided with the first support portion 71 and a second portion 54G provided with the second support portion 72. The first portion 54F (the first support portion 71) and the second portion 54G (the second support portion 72) are inclined with respect to each other and have the first bending portion 54E therebetween. Further, axes of the first support portion 71 and the second support portion 72 are inclined with respect to each other.

[0064] Similarly, the second arm tip 67 includes a second bending portion 67E between the third support portion 73 and the fourth support portion 74. Thus, the second bending portion 67E divides the second arm tip 67 into a third portion 67F provided with the third support portion 73 and a fourth portion 67G provided with the fourth support portion 74. The third portion 67F and the fourth portion 67G are inclined with respect to each other and have the second bending portion 67E therebetween. Further, axes of the third support portion 73 and the fourth support portion 74 are inclined with respect to each other.

[0065] The first portion 54F and the third portion 67F provided on both sides of each first roller receiving portion 69A are provided parallel to each other. In addition, the axes of both the first support portion 71 and the third support portion 73 are provided coaxially with a common axis X4 (an axis common to the first support portion 71 and the third support portion 73). The fourth portion 67G and the second portion 54G provided on both sides of each second roller receiving portion 69B are provided parallel to each other. In addition, the axes of both the fourth support portion 74 and the second support portion 72 are provided coaxially with a common axis X5 (an axis common to the fourth support portion 74 and the second support portion 72).

[0066] Next, a method for attaching the drive roller 21 to the base 20 will be described. When the drive roller 21 is placed in the first roller receiving portion 69A, the operator places the roller body 44 in the first roller receiving portion 69A such that the roller body 44 is coaxial with the first support portion 71 and the third support portion 73. Then, the operator inserts the shaft 43 in the order of the first support portion 71, the roller body 44, and the third support portion 73 into the first support portion, the roller body, and the third support portion. The second end 43B of the shaft 43 is press-fitted and fixed to the third support portion 73, and the first end 43A of the shaft is press-fitted and fixed to the first support portion 71. When press-fitting the shaft 43 into the first support portion 71 and the third support portion 73, an attachment base can be used. For example, the attachment base engages with the first support portion 71 and the third support portion 73 to fix the positions of both the first support portion 71 and the third support portion 73.

[0067] Similarly, when the drive roller 21 is placed in the second roller receiving portion 69B, the operator places the roller body 44 in the second roller receiving portion 69B such that the roller body 44 is coaxial with the fourth support portion 74 and the second support portion 72. Then, the operator inserts the shaft 43 in the order of the fourth support portion 74, the roller body 44, and the second support portion 72 into the fourth support portion, the roller body, and the second support portion. The second end 43B of the shaft 43 is press-fitted and fixed to the second support portion 72, and the first end 43A of the shaft is press-fitted and fixed to the fourth support portion 74. When press-fitting the shaft 43 into the fourth support portion 74 and the second support portion 72, an attachment base can be used. For example, the attachment base engages with the fourth support portion 74 and the second support portion 72 to fix the positions of both the fourth support portion 74 and the second support portion 72.

[0068] In the drive disk 4 according to the present embodiment, the main part of the base 20 (the main part rotatably supporting the drive roller 21) can be formed by the first plate-like metal member 47 and the second plate-like metal member 48, so that the drive disk 4 can be easily manufactured. Each first arm portion 52 and each second arm portion 62 support the first end 43A of one of the two adjacent drive rollers 21 and the second end 43B of the other of the two adjacent drive rollers 21. Therefore, the drive rollers 21 can be arranged with extremely high space efficiency. More specifically, a plurality of first arm portions 52 and a plurality of second arm portions 62 are alternately arranged in the circumferential direction of the drive disk 4. One first arm portion 52 includes a first support portion 71 and a second support portion 72, and one second arm portion 62 includes a third support portion 73 and a fourth support portion 74. Therefore, the drive rollers 21 can be arranged with extremely high space efficiency.

[0069] The first arm tip 54 is provided with a first bent portion 54E, and the axes of both the first support portion 71 and the second support portion 72 are inclined to each other. In addition, the second arm tip 67 is provided with a second bent portion 67E, and the axes of both the third support portion 73 and the fourth support portion 74 are inclined to each other. Therefore, the adjacent drive rollers 21 have axes with different extending directions from each other, which enables the drive rollers 21 to be arranged at rotationally symmetric positions.

[0070] The shaft 43 is press-fitted into the first support portion 71 to the fourth support portion 74, and thus, each first arm portion 52 and each second arm portion 62 are connected by the shaft 43. Therefore, the displacement of each first arm portion 52 and each second arm portion 62 can be suppressed, and the rigidity of the drive disk 4 can be improved.

[0071] The specific embodiments of the present invention have been described above, but the present invention should not be limited by the foregoing embodiments, and various modifications and changes can be made within the scope of the present invention. For example, the first support portion 71 to the fourth support portion 74 may include grooves opening toward the first direction instead of through holes. In this case, the shaft 43 can be inserted into the first support portion 71 to the fourth support portion 74 from the direction in which the grooves open, to facilitate the attachment operation of each drive roller 21.

[0072] In the above-described embodiment, each drive roller 21 includes a shaft 43 and a roller body 44 that is rotatable relative to the shaft 43. In other embodiments, each drive roller 21 may include a shaft 43 and a roller body 44 that is not rotatable relative to the shaft 43. For example, the shaft 43 may be press-fitted into the roller body 44, and the shaft 43 and the roller body 44 may be connected and integrated. In this case, the first end 43A of the shaft 43 may be rotatably supported by the first support portion 71 or the fourth support portion 74, and the second end 43B of the shaft may be rotatably supported by the third support portion 73 or the second support portion 72.

[0073] When placing the drive roller 21 in the first roller receiving portion 69A, the operator places the roller body 44 in the first roller receiving portion 69A such that the roller body 44 is coaxial with the first support portion 71 and the third support portion 73. Then, the operator inserts the shaft 43 into the first support portion, the roller body, and the third support portion in the order of the first support portion 71, the roller body 44, and the third support portion 73. At this time, the central portion of the shaft 43 is press-fitted and fixed to the roller body 44. The roller body 44 cannot pass through the first support portion 71 and the third support portion 73, and thus, the position of the drive roller 21 relative to the first arm tip 54 and the second arm tip 67 is fixed in the axial direction of the shaft 43. The shaft 43 is rotatably supported by the first support portion 71 and the third support portion 73 so that the drive roller 21 can rotate. As a method of placing the drive roller 21 in the second roller receiving portion 69B, the method of placing the drive roller 21 in the first roller receiving portion 69A may be used.

Claims

1. A driving disk, the driving disk being arranged on both sides of an annular main wheel and configured to rotate the main wheel about a central axis and an annular axis by applying a frictional force to the main wheel, each driving disk in the driving disks comprising: a disk-shaped base rotatably supported by a frame; and a plurality of rollers rotatably supported by an outer peripheral portion of the base, inclined with respect to each other and in contact with the main wheel, wherein the base includes a first plate-shaped metal member and a second plate-shaped metal member, the first plate-shaped metal member includes a first central portion and a plurality of first arm portions radially extending outward from the first central portion, the second plate-shaped metal member includes a second central portion and a plurality of second arm portions radially extending outward from the second central portion, the first central portion and the second central portion are arranged coaxially with each other, each of the plurality of rollers has a first end and a second end in a direction of a rotation axis of the roller, each of the plurality of first arm portions includes a first support portion and a second support portion, the second support portion being arranged inside the first support portion in a radial direction of the base, each of the plurality of second arm portions includes a third support portion and a fourth support portion, the fourth support portion being arranged outside the third support portion in a radial direction of the base, a first end of one of two adjacent rollers is supported by the first support portion and a second end of the one roller is supported by the third support portion, a first end of the other of two adjacent rollers is supported by the fourth support portion and a second end of the other roller is supported by the second support portion, the first support portion and the second support portion are inclined with respect to each other and there is a first bent portion between the first support portion and the second support portion, and the third support portion and the fourth support portion are inclined with respect to each other and there is a second bent portion between the third support portion and the fourth support portion.

2. The drive disk according to claim 1, wherein, The first support portion and the third support portion are arranged parallel to each other, and the second support portion and the fourth support portion are arranged parallel to each other.

3. The drive disk according to claim 2, wherein, In a circumferential direction of the first plate-shaped metal member and the second plate-shaped metal member, a tip end of each of the plurality of second arm portions is arranged between tip ends of two adjacent first arm portions.

4. The drive disk according to claim 3, wherein, Tip ends of each of the plurality of first arm portions and tip ends of each of the plurality of second arm portions are arranged on a virtual plane perpendicular to a rotation axis of the base.

5. The drive disk according to claim 4, wherein, Tip ends of each of the plurality of first arm portions extend outward in a radial direction of the base, and tip ends of each of the plurality of second arm portions extend inward in a radial direction of the base.

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