Driving wheel and carriage

Abstract

To perform instantaneous turnaround in a case in which wheels are not driven.SOLUTION: A driving wheel includes a first input shaft 25A and a second input shaft 25B which are coaxial with each other, a first output shaft 40A and a second output shaft 40B which are coaxial with each other, an axle 37 connected to a wheel 15, a turning shaft 35 turnably supporting the wheel through the axle, a first transmission mechanism 13A for transmitting the torque of the first input shaft to the first output shaft, a second transmission mechanism 13B for transmitting the torque of the second input shaft to the second output shaft, a first power conversion mechanism 14A including a conversion driven gear 42 together with the wheel and a first conversion driving gear 41A which is provided on the first output shaft, and a second power conversion mechanism 14B including a conversion driven gear and a second conversion driving gear 41B provided on the second output shaft, wherein the conversion driven gear is singly constructed and is used in common to the first power conversion mechanism and the second power conversion mechanism.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a drive wheel and a bogie. [Background technology]

[0002] For example, Patent Document 1 discloses a steering mechanism for an omnidirectional vehicle in which a plurality of steering shafts are rotatably provided on a vehicle body, each of which is provided with a wheel fixed to an axle, and the vehicle travels by turning each wheel in any direction. The steering shaft is provided with a first drive shaft and a second drive shaft arranged coaxially as conventional drive wheels, a drive unit for driving the first drive shaft and the second drive shaft, a driven bevel gear provided on the axle, a first drive bevel gear provided on the first drive shaft and meshing with the driven bevel gear, and a second drive bevel gear provided on the second drive shaft and meshing with the driven bevel gear. The wheels are provided at positions offset by a predetermined distance from the axial centers of the first drive shaft and the second drive shaft in the direction along the axle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 7-64206 Summary of the Invention [Problem to be solved by the invention]

[0004] The drive wheels described in Patent Document 1 are equipped with a differential omnidirectional movement mechanism. However, in conventional drive wheels, the wheels are located at a position offset by a certain distance in the direction along the axle from the axial center of the first drive shaft and the second drive shaft, which serve as the turning shaft. Therefore, in the conventional drive wheels, when the vehicle body is moved by an external force such as manually without being driven by a drive unit, the wheels do not smoothly turn around the turning shaft, making it difficult to change direction instantly.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a drive wheel and a bogie that are equipped with a differential omnidirectional movement mechanism and can perform instantaneous direction changes when the wheels are not driven. [Means for solving the problem]

[0006] In order to achieve the above object, a drive wheel according to one aspect of the present disclosure includes a first input shaft and a second input shaft arranged coaxially, a first output shaft and a second output shaft arranged coaxially in parallel to the first input shaft and the second input shaft, an axle connected to a wheel, a turning shaft arranged coaxially with the first input shaft and the second input shaft and supporting the wheel so that the wheel can turn via the axle, a first transmission mechanism that transmits a rotational force of the first input shaft to the first output shaft, a second transmission mechanism that transmits a rotational force of the second input shaft to the second output shaft, a conversion driven gear provided together with the wheel, and a transmission gear that meshes with the conversion driven gear and is provided on the first output shaft. the first power conversion mechanism including a first conversion drive gear connected to the first output shaft and a second conversion drive gear meshing with the conversion driven gear and provided on the second output shaft, the conversion driven gear being formed as a single gear and being used in common by the first power conversion mechanism and the second power conversion mechanism, a vertical rotation axis of the wheel extending along a vertical direction perpendicular to the axis of the axle is shifted horizontally relative to the axis of the turning shaft perpendicular to the axis of the axle, and a horizontal rotation axis of the wheel extending along a horizontal direction perpendicular to the axis of the axle is arranged perpendicular to the axis of the turning shaft.

[0007] In a preferred embodiment of the drive wheel, the wheel is a single wheel, and the vertical rotation axis and the horizontal rotation axis are on the equatorial plane of the wheel.

[0008] In a preferred embodiment of the drive wheel, the wheel is a pair of wheels, and the vertical rotation axis and the horizontal rotation axis are located at the center between the wheels.

[0009] In order to achieve the above object, a bogie according to one aspect of the present disclosure includes any one of the drive wheels described above and a bogie body to which the drive wheel is attached. Effect of the Invention

[0010] According to the present disclosure, a differential omnidirectional movement mechanism is provided, enabling instantaneous direction changes when the wheels are not driven. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a basic configuration of a drive wheel according to the first embodiment. [Diagram 2] FIG. 2 is a front view showing the basic configuration of the drive wheel of the first embodiment. [Diagram 3] FIG. 3 is a side view showing the basic configuration of the drive wheel of the first embodiment. [Figure 4] FIG. 4 is a perspective view showing a drive system for the drive wheels of the first embodiment. [Diagram 5] FIG. 5 is a cross-sectional view showing a drive system for a drive wheel according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a drive system for a drive wheel according to the first embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a driving force transmission path of the driving wheels in the first embodiment. [Figure 8] FIG. 8 is a perspective view showing a drive system for drive wheels according to the second embodiment. [Figure 9] FIG. 9 is a front view showing the basic configuration of a drive wheel according to the second embodiment. [Figure 10] FIG. 10 is a side view showing the basic configuration of a drive wheel according to the second embodiment. [Figure 11] FIG. 11 is a perspective view showing a drive system for drive wheels according to the second embodiment. [Figure 12] FIG. 12 is a cross-sectional view showing a drive system for a drive wheel according to the second embodiment. [Figure 13] FIG. 13 is a cross-sectional view showing a drive system for a drive wheel according to the second embodiment. [Figure 14] FIG. 14 is a schematic diagram showing a driving force transmission path of the driving wheels in the second embodiment. [Figure 15] FIG. 15 is a schematic diagram illustrating an example of the configuration of a cart according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Preferred embodiments of the drive wheel and the bogie according to the present disclosure will be described in detail below with reference to the drawings. Note that the present invention is not limited to these embodiments, and when there are multiple embodiments, the present invention also includes a configuration in which each embodiment is combined. Furthermore, the components in the embodiments include those that a person skilled in the art can easily imagine, those that are substantially the same, and those that are within the so-called equivalent range.

[0013] FIG. 15 is a schematic diagram illustrating an example of the configuration of a cart according to an embodiment.

[0014] The cart 100 includes a cart body 101 , a handle portion 102 , four drive wheels 110 ( 120 ), a power supply portion 104 , and a control device 105 .

[0015] The dolly body 101 is, for example, a flat plate material, and has a rectangular shape in a plan view. A handle portion 102 is fixed to one side of the dolly body 101 in the longitudinal direction. Four drive wheels 110 are attached to the four corners of the rear surface of the dolly body 101. The four drive wheels 110 are rotatable and steerable. In addition, a power supply portion 104 and a control device 105 are attached to the rear surface of the dolly body 101 between the front and rear drive wheels 110. The control device 105 includes a computer system. The computer system includes a processor such as a CPU, and a memory such as a ROM or RAM. Thus, in the dolly 100, the control device 105 controls the drive wheels 110.

[0016] The cart body 101 has a flat surface, and thus an object to be transported can be placed on the flat surface. That is, the cart 100 can be configured as an automatic guided vehicle (AGV). The cart 100 can also be configured as a device that travels by placing equipment along the flat surface of the cart body 101. Examples of the equipment include various types of equipment, such as a hand lifter, a forklift, a picking robot, and medical equipment.

[0017] The number and arrangement of the drive wheels 110 of the dolly 100 and the device are not limited to the above-mentioned configuration. For example, in the above-mentioned four-wheel configuration, the dolly 100 and the device may have a pair of drive wheels 110 attached to the rear side of the dolly 100 and a pair of driven wheels attached to the front side of the dolly 100. In addition, although not shown in the figure, in a configuration with three or more wheels, the dolly 100 and the device may have one drive wheel 110 and all the other wheels may be driven wheels. In addition, although not shown in the figure, in a configuration with three or more wheels, the dolly 100 and the device may have no driven wheels and all the wheels may be drive wheels 110. In other words, in a configuration with three or more wheels, the dolly 100 and the device may have at least one drive wheel 110.

[0018] [Driving Wheel Embodiment 1] FIG. 1 is a perspective view showing the basic configuration of a drive wheel of embodiment 1. FIG. 2 is a front view showing the basic configuration of a drive wheel of embodiment 1. FIG. 3 is a side view showing the basic configuration of a drive wheel of embodiment 1. FIG. 4 is a perspective view showing a drive system of a drive wheel of embodiment 1. FIG. 5 is a cross-sectional view (cross-sectional view taken along line AA in FIG. 3) showing the drive system of a drive wheel of embodiment 1. FIG. 6 is a cross-sectional view (cross-sectional view taken along line BB in FIG. 3) showing the drive system of a drive wheel of embodiment 1. FIG. 7 is a schematic diagram showing a drive force transmission path of a drive wheel of embodiment 1.

[0019] In the following description, of the first, second, and third directions that intersect with each other, the first direction is referred to as the "front-rear direction X", the second direction is referred to as the "width direction Y", and the third direction is referred to as the "up-down direction Z". The front-rear direction X, the width direction Y, and the up-down direction Z are perpendicular to each other. The front-rear direction X typically corresponds to the direction along which the drive wheel 110 moves straight. In FIG. 1, the front-rear direction X, the width direction Y, and the up-down direction Z are shown by double-headed arrows, but in other figures, they are shown in a coordinate system with single-headed arrows.

[0020] The drive wheel 110 has a main body 10 fixed to the bogie body 101 of the bogie 100 as described above, and based on this main body 10, a drive mechanism 11, a rotating section 12, a transmission mechanism 13, a power conversion mechanism 14, and wheels 15 are provided.

[0021] The main body 10 is formed in a plate shape with the plate surfaces facing up and down. The drive mechanism 11 inputs a rotational force and is mainly provided above the main body 10. The swivel unit 12 is mainly disposed below the main body 10. The transmission mechanism 13 transmits the rotational force input by the drive mechanism 11. The power conversion mechanism 14 transmits the rotational force of the transmission mechanism 13 to the wheels 15. The wheels 15 are single wheels that are freely rotatable by the rotational force input via the drive mechanism 11, the transmission mechanism 13, and the power conversion mechanism 14, and can be steered by the swivel unit 12.

[0022] The drive mechanism 11 has a first belt drive mechanism 22A as a first drive mechanism and a second belt drive mechanism 22B as a second drive mechanism. The first belt drive mechanism 22A includes a first drive unit 23A, a first drive pulley 24A, a first input shaft 25A, a first driven pulley 26A, and a first drive belt 27A. The first drive unit 23A is composed of a motor. The first drive unit 23A is fixed to the main body 10. The first drive unit 23A has a drive shaft 23Aa that protrudes above the main body 10 and extends in the vertical direction. The first drive pulley 24A is fixed to the drive shaft 23Aa. The first input shaft 25A is provided extending in the vertical direction so as to be parallel to the drive shaft 23Aa, and is supported rotatably around the axis O1. The first driven pulley 26A is fixed to a portion of the first input shaft 25A that protrudes above the main body 10. The first driven pulley 26A and the first driving pulley 24A are arranged side by side in a direction perpendicular to the first input shaft 25A and the driving shaft 23Aa. The first driving belt 27A is formed in an annular shape and is wound around the first driven pulley 26A and the first driving pulley 24A. Therefore, in the first belt driving mechanism 22A, the first driving pulley 24A is rotated by the driving of the first driving unit 23A, and this rotation is transmitted from the first driving pulley 24A to the first driven pulley 26A via the first driving belt 27A, thereby rotating the first input shaft 25A.

[0023] The second belt drive mechanism 22B includes a second drive unit 23B, a second drive pulley 24B, a second input shaft 25B, a second driven pulley 26B, and a second drive belt 27B. The second drive unit 23B is composed of a motor. The second drive unit 23B is fixed to the main body 10. The second drive unit 23B has a drive shaft 23Ba that protrudes above the main body 10 and extends in the vertical direction. The second drive pulley 24B is fixed to the drive shaft 23Ba. The second drive pulley 24B is formed to have the same diameter as the first drive pulley 24A. The second input shaft 25B is provided to extend in the vertical direction so as to be parallel to the drive shaft 23Ba, and is supported rotatably around the axis O1. The second input shaft 25B has a cylindrical shape, passes through the first input shaft 25A, and is arranged outside the first input shaft 25A so as to rotate independently of the first input shaft 25A. The second driven pulley 26B is fixed to a portion of the second input shaft 25B that protrudes upward from the main body 10. The second driven pulley 26B is formed to have the same diameter as the first driven pulley 26A and is located below the first driven pulley 26A. The second driven pulley 26B and the second driving pulley 24B are arranged side by side in a direction perpendicular to the second input shaft 25B and the driving shaft 23Ba. The second driving belt 27B is formed in an annular shape and is wound around the second driven pulley 26B and the second driving pulley 24B. Therefore, the second belt driving mechanism 22B drives the second driving unit 23B, whereby the second driving pulley 24B rotates, and this rotation is transmitted from the second driving pulley 24B to the second driven pulley 26B via the second driving belt 27B, causing the second input shaft 25B to rotate.

[0024] The rotating part 12 includes a rotating shaft 35 and a support part 36. The rotating shaft 35 has an axis O1 at the center of the disk shape, and is rotatably supported via a bearing 45 (see FIG. 5) provided between the rotating shaft 35 and the main body 10. As a result, the rotating shaft 35 is supported so as to be rotatable relatively to the main body 10 around the axis O1.

[0025] 5, the rotating shaft 35 is disposed so as to penetrate the first input shaft 25A of the first belt drive mechanism 22A in the vertical direction along the axis O1, and rotatably supports it via a bearing 43. Therefore, the first input shaft 25A is supported so as to be rotatable relative to the rotating shaft 35 about the axis O1, and is also supported so as to be rotatable relative to the main body 10 about the axis O1. That is, the rotating shaft 35 is provided so as to be rotatable relative to the main body 10 regardless of the rotation of the first input shaft 25A. Therefore, the driving wheel 110 of the embodiment can input a rotational force to the first input shaft 25A on the axis O1, which is the axis of rotation of the wheel 15.

[0026] The revolving shaft 35 has the second input shaft 25B of the second belt drive mechanism 22B facing upward and rotatably supported via a bearing 50. The second input shaft 25B is inserted through the first input shaft 25A and rotatably arranged on the outside of the first input shaft 25A via a bearing 44. Therefore, the second input shaft 25B is supported rotatably relative to the revolving shaft 35 via the first input shaft 25A around the axis O1, and is also supported rotatably relative to the main body 10 around the axis O1. That is, the revolving shaft 35 is provided rotatably relative to the main body 10 regardless of the rotation of the second input shaft 25B. Therefore, the driving wheel 110 of the embodiment can input a rotational force to the second input shaft 25B on the axis O1, which is the revolving axis of the wheel 15. With this configuration, the first input shaft 25A, the second input shaft 25B, and the revolving shaft 35 are rotatably arranged coaxially along the axis O1.

[0027] In the swivel unit 12, a support unit 36 ​​is provided below the swivel shaft 35 so as to extend downward. As shown in Figs. 5 and 6, the support unit 36 ​​has support members 36a, 36b arranged on both sides of the wheel 15 in the width direction Y. The wheel 15 is provided on an axle 37 extending in the width direction Y along an axis O2 perpendicular to the direction in which the axis O1 extends (the up-down direction Z). In this embodiment, the wheel 15 is fixed to the axle 37. The axle 37 has each end along the axis O2 rotatably supported by the support members 36a, 36b via bearings 48 (see Fig. 6).

[0028] In the swivel portion 12, the swivel shaft 35 and the support portion 36 support a first output shaft 40A and a second output shaft 40B, as shown in FIG.

[0029] The first output shaft 40A is provided linearly along an axis O3 (see FIGS. 2, 3, and 6) that extends parallel to the direction in which the axis O1 extends (the vertical direction Z). The first output shaft 40A is supported by the rotating shaft 35 via a bearing 46 so as to be rotatable about the axis O3.

[0030] The second output shaft 40B is provided linearly along an axis O4 (see FIGS. 2, 3, and 6) that extends parallel to the direction in which the axis O1 extends (the vertical direction Z). The second output shaft 40B is inserted through the first output shaft 40A and disposed on the outside of the first output shaft 40A so as to be rotatable about the axis O4 via a bearing 47, and is supported by the support member 36b of the support portion 36 so as to be rotatable about the axis O4 via the bearing 47. Therefore, the second output shaft 40B is supported by the first output shaft 40A so as to be rotatable relative to the rotating shaft 35 around the axis O4, and is also supported by the support portion 36 so as to be rotatable relative to the axis O4.

[0031] With this configuration, the first output shaft 40A and the second output shaft 40B are coaxially arranged to be rotatable along their respective axis centers O3 and O4.

[0032] As shown in FIGS. 2 to 6, the transmission mechanism 13 has a first transmission mechanism 13A and a second transmission mechanism 13B.

[0033] The first transmission mechanism 13A is also referred to as a first transmission gear mechanism. The first transmission mechanism 13A transmits the rotational force of the first input shaft 25A to the first output shaft 40A. The first transmission mechanism 13A includes a first driving gear 31A and a first driven gear 32A. In the driving wheel 110 of the embodiment, the first driving gear 31A and the first driven gear 32A are configured by spur gears.

[0034] In the first transmission mechanism 13A, the first driving gear 31A is fixed to the first input shaft 25A. Therefore, the first driving gear 31A rotates around the axis O1 of the first input shaft 25A. The first driven gear 32A is fixed to the first output shaft 40A. Therefore, the first driven gear 32A rotates around the axis O3 of the first output shaft 40A. The first driving gear 31A meshes with the first driven gear 32A. Therefore, the first transmission mechanism 13A transmits the rotational force of the first input shaft 25A from the first driving gear 31A to the first driven gear 32A to provide the rotational force to the first output shaft 40A.

[0035] The second transmission mechanism 13B is also referred to as a second transmission gear mechanism. The second transmission mechanism 13B transmits the rotational force of the second input shaft 25B to the second output shaft 40B. The second transmission mechanism 13B includes a second driving gear 31B and a second driven gear 32B. In the driving wheel 110 of the embodiment, the second driving gear 31B and the second driven gear 32B are configured by spur gears.

[0036] In the second transmission mechanism 13B, the second driving gear 31B is fixed to the second input shaft 25B. Therefore, the second driving gear 31B rotates around the axis O1 of the second input shaft 25B. The second driven gear 32B is fixed to the second output shaft 40B. Therefore, the second driven gear 32B rotates around the axis O4 of the second output shaft 40B. The second driving gear 31B meshes with the second driven gear 32B. Therefore, the second transmission mechanism 13B transmits the rotational force of the second input shaft 25B from the second driving gear 31B to the second driven gear 32B to provide the rotational force to the second output shaft 40B.

[0037] In this transmission mechanism 13, the first driving gear 31A of the first transmission mechanism 13A and the second driving gear 31B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth. Also, in the transmission mechanism 13, the first driven gear 32A of the first transmission mechanism 13A and the second driven gear 32B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth.

[0038] As shown in FIGS. 3 to 6, the power conversion mechanism 14 has a first power conversion mechanism 14A and a second power conversion mechanism 14B.

[0039] The first power converting mechanism 14A is also referred to as a first power converting gear mechanism. The first power converting mechanism 14A transmits the rotational force of the first output shaft 40A to the wheels 15. The first power converting mechanism 14A includes a first converted driving gear 41A and a converted driven gear 42. In the driving wheel 110 of the embodiment, the first converted driving gear 41A and the converted driven gear 42 are configured as bevel gears.

[0040] In the first power conversion mechanism 14A, the first converted driving gear 41A is fixed to the first output shaft 40A. Therefore, the first converted driving gear 41A rotates around the axis O3 together with the first output shaft 40A. In addition, the converted driven gear 42 is fixed to the axle 37. Therefore, the converted driven gear 42 rotates around the axis O2 together with the axle 37 and the wheels 15. The first converted driving gear 41A meshes with the converted driven gear 42. Therefore, the first power conversion mechanism 14A transmits the rotational force of the first output shaft 40A from the first converted driving gear 41A to the converted driven gear 42 to provide the rotational force to the axle 37 and the wheels 15.

[0041] The second power converting mechanism 14B is also referred to as a second power converting gear mechanism. The second power converting mechanism 14B transmits the rotational force of the second output shaft 40B to the wheels 15. The second power converting mechanism 14B includes a second converted driving gear 41B and a converted driven gear 42. The converted driven gear 42 is shared with the first power converting mechanism 14A. In the driving wheel 110 of the embodiment, the second converted driving gear 41B and the converted driven gear 42 are configured with bevel gears.

[0042] In the second power conversion mechanism 14B, the second conversion driving gear 41B is fixed to the second output shaft 40B. Therefore, the second conversion driving gear 41B rotates around the axis O4 together with the second output shaft 40B. The second conversion driving gear 41B meshes with the conversion driven gear 42. Therefore, the second power conversion mechanism 14B transmits the rotational force of the second output shaft 40B from the second conversion driving gear 41B to the conversion driven gear 42, thereby providing the rotational force to the axle 37 and the wheels 15.

[0043] In this power conversion mechanism 14, the first conversion driving gear 41A of the first power conversion mechanism 14A and the second conversion driving gear 41B of the second power conversion mechanism 14B are positioned symmetrically at 180° with respect to the axis O2 of the axle 37, which is the center of rotation of the single common conversion driven gear 42. In addition, in this power conversion mechanism 14, the first conversion driving gear 41A of the first power conversion mechanism 14A and the second conversion driving gear 41B of the second power conversion mechanism 14B have the same pitch circle diameter and the same number of teeth.

[0044] As shown in FIG. 3, the driving wheel 110 of the embodiment is arranged such that the vertical rotation axis O5 of the wheel 15 along the vertical direction perpendicular to the axis O2 of the axle 37 is offset from the axis O1 of the turning shaft 35 in the horizontal direction (front-rear direction X) intersecting or perpendicular to the axis O2 of the axle 37. The vertical rotation axis O5 of the wheel 15 is the center of the single wheel 15 in the direction along the axis O2 of the axle 37 and perpendicular to the axis O2. Furthermore, the driving wheel 110 of the embodiment is arranged such that the horizontal rotation axis O10 of the wheel 15 along the horizontal direction perpendicular to the axis O2 of the axle 37 is perpendicular to the axis O1 of the turning shaft 35. The horizontal rotation axis O10 of the wheel 15 is the center of the single wheel 15 in the direction along the axis O2 of the axle 37 and perpendicular to the axis O2. The vertical rotation axis O5 and the horizontal rotation axis O10 are perpendicular to each other. This offset relationship is achieved by shifting the coaxial axes O3, O4 of the first output shaft 40A and the second output shaft 40B horizontally with respect to the axis O1 of the first input shaft 25A and the second input shaft 25B that are coaxial with the turning shaft 35, and by the arrangement of the wheels 15 on the axle 37.

[0045] The drive wheel 110 can rotate and steer the wheels 15 by rotating the first input shaft 25A and the second input shaft 25B with the drive mechanism 11. For example, the wheels 15 can be rotated without steering by rotating the first input shaft 25A and rotating the second input shaft 25B in the opposite direction to the first input shaft 25A, and making the rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B the same. At this time, by making the rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B different, the wheels 15 can be steered while rotating or stopped.

[0046] Here, the operation of the driving wheel 110 will be described. As shown in Fig. 7, when the first input shaft 25A of the driving wheel 110 rotates in the A1 direction, the first driving gear 31A provided on the first input shaft 25A rotates in the same direction, and the first driven gear 32A meshing with the first driving gear 31A rotates in the A2 direction opposite to the A1 direction. Then, the first converted driving gear 41A provided on the first output shaft 40A integrally with the first driven gear 32A rotates in the same direction. Then, the converted driven gear 42 meshing with the first converted driving gear 41A rotates in the C direction, and applies a rotational force in the C direction to the axle 37 and the wheel 15 integral with the converted driven gear 42. On the other hand, when the second input shaft 25B rotates in the B1 direction, which is the opposite direction to the A1 direction, the second driving gear 31B provided on the second input shaft 25B rotates in the same direction, and the second driven gear 32B meshing with the second driving gear 31B rotates in the B2 direction, which is the same direction as the B1 direction. Then, the second conversion driving gear 41B provided on the second output shaft 40B integrally with the second driven gear 32B rotates in the same direction. Then, the conversion driven gear 42 meshing with the second conversion driving gear 41B rotates in the C direction, and applies a rotational force in the C direction to the axle 37 and the wheel 15 integral with the conversion driven gear 42.

[0047] At this time, when the rotation speed of the second input shaft 25B is reduced relative to the rotation speed of the first input shaft 25A, the rotation speed input from the second conversion driving gear 41B to the axle 37 and the wheels 15 via the conversion driven gear 42 becomes lower than the rotation speed input from the first conversion driving gear 41A to the axle 37 and the wheels 15 via the conversion driven gear 42. Then, the turning shaft 35 rotates by the rotation speed difference, and the wheels 15 are turned and steered. Also, when the rotation of the first input shaft 25A or the second input shaft 25B is stopped, the rotation speed input from the first conversion driving gear 41A or the second conversion driving gear 41B to the axle 37 and the wheels 15 via the conversion driven gear 42 becomes zero, and the wheels 15 are turned and steered without rotating.

[0048] Furthermore, when the drive wheels 110 do not drive the wheels 15, the wheels 15 can passively turn due to an external force acting from the horizontal direction. That is, the cart 100 can automatically travel and steer, and can also be manually traveled and steered by an operator.

[0049] The driving wheel 110 of the above-described embodiment is characterized in that it includes a first input shaft 25A and a second input shaft 25B that are arranged coaxially with each other, a first output shaft 40A and a second output shaft 40B that are parallel to the first input shaft 25A and the second input shaft 25B and arranged coaxially with each other, an axle 37 connected to the wheels 15, a turning shaft 35 that is arranged coaxially with the first input shaft 25A and the second input shaft 25B and supports the wheels 15 so that they can turn via the axle 37, a first transmission mechanism 13A that transmits the rotational force of the first input shaft 25A to the first output shaft 40A, a second transmission mechanism 13B that transmits the rotational force of the second input shaft 25B to the second output shaft 40B, and a variable torque converter 13C that is provided together with the wheels 15. The vehicle includes a first power conversion mechanism 14A including a converted driven gear 42 and a first converted drive gear 41A that meshes with the converted driven gear 42 and is provided on the first output shaft 40A, and a second power conversion mechanism 14B including a converted driven gear 42 and a second converted drive gear 41B that meshes with the converted driven gear 42 and is provided on the second output shaft 40B, and the vertical rotation axis O5 of the wheel 15, which runs along the vertical direction perpendicular to the axis O2 of the axle 37, is shifted horizontally relative to the axis O1 of the turning shaft 35, which is perpendicular to the axis O2 of the axle 37, and the horizontal rotation axis O10 of the wheel 15, which runs along the horizontal direction perpendicular to the axis O2 of the axle 37, is arranged perpendicular to the axis O2 of the turning shaft 35.

[0050] The driving wheel 110 has a differential omnidirectional movement mechanism. That is, in the driving wheel 110, the rotational force of the first input shaft 25A and the second input shaft 25B is transmitted to the first output shaft 40A and the second output shaft 40B via the first transmission mechanism 13A and the second transmission mechanism 13B, and is transmitted from the first output shaft 40A and the second output shaft 40B to the wheels 15 via the first power conversion mechanism 14A and the second power conversion mechanism 14B. The driving wheel 110 can switch between the rotation of the wheels 15 and the steering of the wheels 15 by adjusting the rotation speed of the first input shaft 25A and the second input shaft 25B.

[0051] In particular, in this drive wheel 110, the vertical rotation axis O5 of the wheel 15, which is aligned in the vertical direction and perpendicular to the axis O2 of the axle 37, is arranged offset in the horizontal direction perpendicular to the axis O2 of the axle 37 with respect to the axis O1 of the turning shaft 35, and the horizontal rotation axis O10 of the wheel 15, which is aligned in the horizontal direction and perpendicular to the axis O2 of the axle 37, is arranged perpendicular to the axis O2 of the turning shaft 35. Therefore, in the past (for example, Patent Document 1), the wheels were provided at positions offset by a predetermined distance in the direction along the axles from the axial centers of the first and second driving shafts, which serve as the turning shafts, and therefore when an external force is applied to the vehicle body in the horizontal direction without being driven by a drive device, the wheels do not smoothly turn around the turning shaft, making it difficult to change direction instantly. In this regard, with the drive wheel 110, due to the above-mentioned configuration, when a horizontal external force is applied to the wheel 15 without driving the wheel 15, the wheel 15 can smoothly turn about the axis O1 of the turning shaft 35. As a result, the drive wheel 110 of the embodiment is provided with a differential omnidirectional movement mechanism, and can instantly change direction when the wheel 15 is not driven.

[0052] In the driving wheel 110 of the embodiment, the wheel 15 is a single wheel, and the vertical rotation axis O5 and the horizontal rotation axis O10 exist on the equatorial plane of the wheel 15. Here, the equatorial plane of the wheel 15 is a plane that is perpendicular to the axle 37 and passes through the center of the wheel 15 in the width direction Y.

[0053] With this drive wheel 110, when the wheel 15 is a single wheel, the vertical rotation axis O5 of the wheel 15, which runs vertically and perpendicular to the axis O2 of the axle 37, can be shifted horizontally relative to the axis O1 of the pivot shaft 35, perpendicular to the axis O2 of the axle 37, and the horizontal rotation axis O10 of the wheel 15, which runs horizontally and perpendicular to the axis O2 of the axle 37, can be positioned perpendicular to the axis O2 of the pivot shaft 35, thereby achieving the effect of enabling instantaneous direction changes even when the wheel 15 is not driven.

[0054] Moreover, the dolly 100 of the embodiment includes the above-mentioned drive wheels 110 and a dolly body 101 to which the drive wheels 110 are attached. Therefore, the basic structure of the dolly 100 can be simplified.

[0055] [Driving Wheel Embodiment 2] FIG. 8 is a perspective view showing a drive system of a drive wheel of the second embodiment. FIG. 9 is a front view showing a basic configuration of a drive wheel of the second embodiment. FIG. 10 is a side view showing a basic configuration of a drive wheel of the second embodiment. FIG. 11 is a perspective view showing a drive system of a drive wheel of the second embodiment. FIG. 12 is a cross-sectional view showing a drive system of a drive wheel of the second embodiment (cross-sectional view taken along CC in FIG. 10). FIG. 13 is a cross-sectional view showing a drive system of a drive wheel of the second embodiment (cross-sectional view taken along DD in FIG. 10). FIG. 14 is a schematic diagram showing a drive force transmission path of a drive wheel of the second embodiment.

[0056] In the following description of the drive wheel 120 of the second embodiment, parts equivalent to those of the drive wheel 110 of the first embodiment are given the same reference numerals.

[0057] The drive wheel 120 has a main body 10 fixed to the cart body 101 of the cart 100 as described above, and based on this main body 10, a drive mechanism 11, a rotating section 12, a transmission mechanism 13, a power conversion mechanism 14, and wheels 15 are provided.

[0058] The main body 10 is formed in a plate shape with the plate surfaces facing up and down. The drive mechanism 11 inputs a rotational force and is mainly provided above the main body 10. The swivel unit 12 is mainly disposed below the main body 10. The transmission mechanism 13 transmits the rotational force input by the drive mechanism 11. The power conversion mechanism 14 transmits the rotational force of the transmission mechanism 13 to the wheels 15. The wheels 15 are dual wheels (drive wheel 15a, driven wheel 15b) that are freely rotatable by the rotational force input via the drive mechanism 11, the transmission mechanism 13, and the power conversion mechanism 14, and can be steered by the swivel unit 12.

[0059] The drive mechanism 11 includes a first drive mechanism 21A and a second drive mechanism 21B.

[0060] The first driving mechanism 21A is configured with a first driving unit that is a motor. The first driving mechanism 21A is attached to the main body 10 so that the axis O6 (see FIG. 12) of the first driving shaft 21Aa extends along the vertical direction Z.

[0061] The second driving mechanism 21B is configured with a second driving unit that is a motor. The second driving mechanism 21B is attached to the main body 10 so that the axis O7 (see FIG. 12) of the second driving shaft 21Ba extends along the vertical direction Z.

[0062] The swivel unit 12 includes a swivel shaft 35 and a support portion 36. The swivel unit 12 is provided such that the support portion 36 extends downward from the lower portion of the swivel shaft 35. The swivel shaft 35 has an axis O1 at the center of the disk shape and is rotatably supported via a bearing 45 (see FIGS. 12 and 13) provided on the outer periphery of the main body 10. As a result, the swivel shaft 35 is supported so as to be rotatable relatively to the main body 10 around the axis O1.

[0063] The swivel shaft 35 is disposed so as to penetrate the first input shaft 25A coaxially with the axis O1 in the vertical direction Z, and rotatably supports the first input shaft 25A at the support portion 36 via a bearing 43b (see FIG. 12). The first input shaft 25A is rotatably supported coaxially with the axis O1 with respect to the main body 10 via a bearing 43a (see FIG. 12). Therefore, the first input shaft 25A is supported so as to be rotatable relative to the swivel shaft 35 around the axis O1, and is also supported so as to be rotatable relative to the main body 10 around the axis O1. That is, the swivel shaft 35 is provided so as to be rotatable relative to the main body 10 regardless of the rotation of the first input shaft 25A. Therefore, the driving wheel 120 of the embodiment can input a rotational force to the first input shaft 25A on the axis O1, which is the axis of rotation of the wheel 15.

[0064] The revolving shaft 35 arranges the second input shaft 25B along the vertical direction Z. The second input shaft 25B is inserted through the first input shaft 25A and rotatably arranged on the outside of the first input shaft 25A via a bearing 44 (see FIG. 12). Therefore, the second input shaft 25B is supported rotatably around the axis O1 relative to the revolving shaft 35 via the first input shaft 25A, and is also supported rotatably around the axis O1 relative to the main body 10. That is, the revolving shaft 35 is provided rotatably with respect to the main body 10 regardless of the rotation of the second input shaft 25B. Therefore, the driving wheel 120 of the embodiment can input a rotational force to the second input shaft 25B on the axis O1, which is the revolving axis of the wheel 15. With this configuration, the first input shaft 25A, the second input shaft 25B, and the revolving shaft 35 are rotatably arranged coaxially along the axis O1.

[0065] The wheel 15 is provided on the support part 36 of the rotating shaft 35. The wheel 15 is integrally provided with an axle 37 extending in the width direction Y along an axis O2 perpendicular to the direction in which the axis O1 extends (the vertical direction Z). The axle 37 is rotatably supported on the support part 36 via a bearing 48 (see FIG. 13) along the axis O2. The axle 37 is provided with each end penetrating and protruding to the outside of the support part 36 in the width direction Y, and the wheels 15a and 15b are provided on each end. In the driving wheel 120 of the embodiment, the wheel 15a is also referred to as a driving wheel, and the wheel 15b is also referred to as a driven wheel. The driving wheel 15a is fixed to one end of the axle 37. The driven wheel 15b is rotatably supported on the other end of the axle 37 via a bearing 49 (see FIG. 13).

[0066] The rotating shaft 35 disposes the first output shaft 40A in the vertical direction Z parallel to the axis O1 on its support portion 36, and rotatably supports it via bearings 46 (see FIG. 13). Therefore, the first output shaft 40A is supported so as to be rotatable relatively to the rotating shaft 35 about an axis O3 parallel to the axis O1.

[0067] The second output shaft 40B is disposed in the support portion 36 of the rotating shaft 35 so as to penetrate therethrough in the vertical direction Z parallel to the axis O1, and is rotatably supported via a bearing 47 (see FIG. 13). Therefore, the second output shaft 40B is supported so as to be rotatable relatively to the rotating shaft 35 about an axis O4 parallel to the axis O1.

[0068] An axis O3 of the first output shaft 40A and an axis O4 of the second output shaft 40B coincide with each other in the vertical direction Z. That is, the first output shaft 40A and the second output shaft 40B are arranged coaxially. The first output shaft 40A and the second output shaft 40B are arranged on a different axis from the first input shaft 25A and the second input shaft 25B. In the driving wheel 120 of the embodiment, the first output shaft 40A is arranged on the lower side in the vertical direction Z, and the second output shaft 40B is arranged on the upper side in the vertical direction Z.

[0069] As shown in FIGS. 9 to 13, the transmission mechanism 13 has a first transmission mechanism 13A and a second transmission mechanism 13B.

[0070] The first transmission mechanism 13A is also referred to as a first transmission gear mechanism. The first transmission mechanism 13A transmits the rotational force of the first drive shaft 21Aa to the first output shaft 40A via the first input shaft 25A. The first transmission mechanism 13A includes a first transmission drive gear 38A, a first transmission driven gear 39A, a first drive gear 31A, and a first driven gear 32A. In the drive wheel 120 of the embodiment, the first transmission drive gear 38A, the first transmission driven gear 39A, the first drive gear 31A, and the first driven gear 32A are configured with spur gears.

[0071] In the first transmission mechanism 13A, the first transmission drive gear 38A is fixed to the first drive shaft 21Aa of the first drive mechanism 21A. Therefore, the first transmission drive gear 38A rotates around the axis O6 of the first drive shaft 21Aa by the rotational force of the first drive mechanism 21A. The first transmission driven gear 39A and the first drive gear 31A are fixed to the first input shaft 25A. Therefore, the first transmission driven gear 39A and the first drive gear 31A rotate around the axis O1 of the first input shaft 25A. The first driven gear 32A is fixed to the first output shaft 40A. Therefore, the first driven gear 32A rotates around the axis O3 of the first output shaft 40A. The first transmission drive gear 38A meshes with the first transmission driven gear 39A. The first drive gear 31A meshes with the first driven gear 32A. Therefore, the first transmission mechanism 13A transmits the rotational force of the first drive mechanism 21A from the first transmission drive gear 38A to the first transmission driven gear 39A to provide the rotational force to the first input shaft 25A, and further transmits the rotational force of the first input shaft 25A from the first drive gear 31A to the first driven gear 32A to provide the rotational force to the first output shaft 40A.

[0072] The second transmission mechanism 13B is also referred to as a second transmission gear mechanism. The second transmission mechanism 13B transmits the rotational force of the second drive shaft 21Ba to the second output shaft 40B via the second input shaft 25B. The second transmission mechanism 13B includes a second transmission drive gear 38B, a second transmission driven gear 39B, a second drive gear 31B, and a second driven gear 32B. In the drive wheel 120 of the embodiment, the second transmission drive gear 38B, the second transmission driven gear 39B, the second drive gear 31B, and the second driven gear 32B are configured with spur gears.

[0073] In the second transmission mechanism 13B, the second transmission drive gear 38B is fixed to the second drive shaft 21Ba of the second drive mechanism 21B. Therefore, the second transmission drive gear 38B rotates around the axis O7 of the second drive shaft 21Ba by the rotational force of the second drive mechanism 21B. The second transmission driven gear 39B and the second drive gear 31B are fixed to the second input shaft 25B. Therefore, the second transmission driven gear 39B and the second drive gear 31B rotate around the axis O1 of the second input shaft 25B. The second driven gear 32B is fixed to the second output shaft 40B. Therefore, the second driven gear 32B rotates around the axis O4 of the second output shaft 40B. The second transmission drive gear 38B meshes with the second transmission driven gear 39B. The second drive gear 31B meshes with the second driven gear 32B. Therefore, the second transmission mechanism 13B transmits the rotational force of the second drive mechanism 21B from the second transmission drive gear 38B to the second transmission driven gear 39B to provide the rotational force to the second input shaft 25B, and further transmits the rotational force of the second input shaft 25B from the second drive gear 31B to the second driven gear 32B to provide the rotational force to the second output shaft 40B.

[0074] In this transmission mechanism 13, the first transmission drive gear 38A of the first transmission mechanism 13A and the second transmission drive gear 38B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth. In addition, in the transmission mechanism 13, the first transmission driven gear 39A of the first transmission mechanism 13A and the second transmission driven gear 39B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth. In addition, in the transmission mechanism 13, the first drive gear 31A of the first transmission mechanism 13A and the second drive gear 31B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth. In addition, in the transmission mechanism 13, the first driven gear 32A of the first transmission mechanism 13A and the second driven gear 32B of the second transmission mechanism 13B have the same pitch circle diameter and the same number of teeth.

[0075] As shown in FIGS. 9 to 13, the power conversion mechanism 14 has a first power conversion mechanism 14A and a second power conversion mechanism 14B.

[0076] The first power converting mechanism 14A is also referred to as a first power converting gear mechanism. The first power converting mechanism 14A transmits the rotational force of the first output shaft 40A to the drive wheel 15a. The first power converting mechanism 14A includes a first converted driving gear 41A and a converted driven gear 42. In the drive wheel 120 of the embodiment, the first converted driving gear 41A and the converted driven gear 42 are configured as bevel gears.

[0077] In the first power conversion mechanism 14A, the first converted driving gear 41A is fixed to the first output shaft 40A. Therefore, the first converted driving gear 41A rotates around the axis O3 together with the first output shaft 40A. In addition, the converted driven gear 42 is fixed to the axle 37. Therefore, the converted driven gear 42 rotates around the axis O2 together with the axle 37 and the driving wheel 15a. The first converted driving gear 41A meshes with the converted driven gear 42. Therefore, the first power conversion mechanism 14A transmits the rotational force of the first output shaft 40A from the first converted driving gear 41A to the converted driven gear 42 to provide the rotational force to the axle 37 and the driving wheel 15a.

[0078] The second power converting mechanism 14B is also referred to as a second power converting gear mechanism. The second power converting mechanism 14B transmits the rotational force of the second output shaft 40B to the drive wheel 15a. The second power converting mechanism 14B includes a second converted driving gear 41B and a converted driven gear 42. The converted driven gear 42 is shared with the first power converting mechanism 14A. In the drive wheel 120 of the embodiment, the second converted driving gear 41B and the converted driven gear 42 are configured as bevel gears.

[0079] In the second power conversion mechanism 14B, the second conversion driving gear 41B is fixed to the second output shaft 40B. Therefore, the second conversion driving gear 41B rotates around the axis O4 together with the second output shaft 40B. The second conversion driving gear 41B meshes with the conversion driven gear 42. Therefore, the second power conversion mechanism 14B transmits the rotational force of the second output shaft 40B from the second conversion driving gear 41B to the conversion driven gear 42, thereby providing the rotational force to the axle 37 and the driving wheel 15a.

[0080] In this power conversion mechanism 14, the first conversion driving gear 41A of the first power conversion mechanism 14A and the second conversion driving gear 41B of the second power conversion mechanism 14B are positioned symmetrically at 180° with respect to the axis O2 of the axle 37, which is the center of rotation of the single common conversion driven gear 42. In addition, in this power conversion mechanism 14, the first conversion driving gear 41A of the first power conversion mechanism 14A and the second conversion driving gear 41B of the second power conversion mechanism 14B have the same pitch circle diameter and the same number of teeth.

[0081] As shown in FIG. 10, the driving wheel 120 of the embodiment is arranged such that the vertical rotation axis O5 of the wheel 15, which is perpendicular to the axis O2 of the axle 37 and aligned along the vertical direction, is offset from the axis O1 of the turning shaft 35 in the horizontal direction (front-rear direction X) that intersects or is perpendicular to the axis O2 of the axle 37. The vertical rotation axis O5 of the wheel 15 passes through the center between the wheels 15a, 15b of the dual wheels 15a, 15b and is perpendicular to the axis O2. Furthermore, the driving wheel 120 of the embodiment is arranged such that the horizontal rotation axis O10 of the wheel 15, which is perpendicular to the axis O2 of the axle 37 and aligned along the horizontal direction, is perpendicular to the axis O1 of the turning shaft 35. The horizontal rotation axis O10 of the wheel 15 passes through the center between the wheels 15a, 15b of the dual wheels 15a, 15b and is perpendicular to the axis O2. The vertical rotation axis O5 and the horizontal rotation axis O10 are perpendicular to each other. This offset relationship is achieved by shifting the coaxial axes O3 and O4 of the first output shaft 40A and the second output shaft 40B horizontally with respect to the axis O1 of the first input shaft 25A and the second input shaft 25B that are coaxial with the revolving shaft 35, and by the arrangement of the wheels 15a and 15b on the axle 37.

[0082] The drive wheel 120 can rotate and steer the wheels 15 by rotating the first input shaft 25A and the second input shaft 25B by the drive mechanism 11. For example, the wheels 15 can be rotated without steering by rotating the first input shaft 25A and rotating the second input shaft 25B in the opposite direction to the first input shaft 25A, and making the rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B the same. At this time, by making the rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B different, the wheels 15 can be steered while rotating or stopped.

[0083] Here, the operation of the drive wheel 120 will be described. As shown in Fig. 14, when the first input shaft 25A of the drive wheel 120 rotates in the A1 direction, the first drive gear 31A provided on the first input shaft 25A rotates in the same direction, and the first driven gear 32A meshing with the first drive gear 31A rotates in the A2 direction, which is opposite to the A1 direction. Then, the first converted drive gear 41A provided on the first output shaft 40A integrally with the first driven gear 32A rotates in the same direction. Then, the converted driven gear 42 meshing with the first converted drive gear 41A rotates in the C direction, and applies a rotational force in the C direction to the axle 37 and the wheel 15 integral with the converted driven gear 42. On the other hand, when the second input shaft 25B rotates in the B1 direction, which is the opposite direction to the A1 direction, the second driving gear 31B provided on the second input shaft 25B rotates in the same direction, and the second driven gear 32B meshing with the second driving gear 31B rotates in the B2 direction, which is the same direction as the B1 direction. Then, the second conversion driving gear 41B provided on the second output shaft 40B integrally with the second driven gear 32B rotates in the same direction. Then, the conversion driven gear 42 meshing with the second conversion driving gear 41B rotates in the C direction, and applies a rotational force in the C direction to the axle 37 and the wheel 15 integral with the conversion driven gear 42.

[0084] At this time, when the rotation speed of the second input shaft 25B is reduced relative to the rotation speed of the first input shaft 25A, the rotation speed input from the second conversion driving gear 41B to the axle 37 and the wheels 15 via the conversion driven gear 42 becomes lower than the rotation speed input from the first conversion driving gear 41A to the axle 37 and the wheels 15 via the conversion driven gear 42. Then, the turning shaft 35 rotates by the rotation speed difference, and the wheels 15 are turned and steered. Also, when the rotation of the first input shaft 25A or the second input shaft 25B is stopped, the rotation speed input from the first conversion driving gear 41A or the second conversion driving gear 41B to the axle 37 and the wheels 15 via the conversion driven gear 42 becomes zero, and the wheels 15 are turned and steered without rotating.

[0085] Furthermore, when the drive wheels 120 do not drive the wheels 15, the wheels 15 can passively turn due to an external force acting from the horizontal direction. That is, the cart 100 can automatically travel and steer, and can also be manually traveled and steered by an operator.

[0086] The driving wheel 120 of the above-described embodiment is characterized in that it includes a first input shaft 25A and a second input shaft 25B that are arranged coaxially with each other, a first output shaft 40A and a second output shaft 40B that are parallel to the first input shaft 25A and the second input shaft 25B and arranged coaxially with each other, an axle 37 connected to the wheels 15, a turning shaft 35 that is arranged coaxially with the first input shaft 25A and the second input shaft 25B and supports the wheels 15 so that they can turn via the axle 37, a first transmission mechanism 13A that transmits the rotational force of the first input shaft 25A to the first output shaft 40A, a second transmission mechanism 13B that transmits the rotational force of the second input shaft 25B to the second output shaft 40B, and a variable torque converter 13C that is provided together with the wheels 15. The vehicle includes a first power conversion mechanism 14A including a converted driven gear 42 and a first converted drive gear 41A that meshes with the converted driven gear 42 and is provided on the first output shaft 40A, and a second power conversion mechanism 14B including a converted driven gear 42 and a second converted drive gear 41B that meshes with the converted driven gear 42 and is provided on the second output shaft 40B, and the vertical rotation axis O5 of the wheel 15, which runs along the vertical direction perpendicular to the axis O2 of the axle 37, is shifted horizontally relative to the axis O1 of the turning shaft 35, which is perpendicular to the axis O2 of the axle 37, and the horizontal rotation axis O10 of the wheel 15, which runs along the horizontal direction perpendicular to the axis O2 of the axle 37, is arranged perpendicular to the axis O2 of the turning shaft 35.

[0087] The driving wheels 120 have a differential omnidirectional movement mechanism. That is, in the driving wheels 120, the rotational force of the first input shaft 25A and the second input shaft 25B is transmitted to the first output shaft 40A and the second output shaft 40B via the first transmission mechanism 13A and the second transmission mechanism 13B, and is transmitted from the first output shaft 40A and the second output shaft 40B to the wheels 15 via the first power conversion mechanism 14A and the second power conversion mechanism 14B. The driving wheels 120 can switch between the rotation of the wheels 15 and the steering of the wheels 15 by adjusting the rotation speed of the first input shaft 25A and the second input shaft 25B.

[0088] In particular, in this drive wheel 120, the vertical rotation axis O5 of the wheel 15, which is aligned in the vertical direction and perpendicular to the axis O2 of the axle 37, is arranged offset in the horizontal direction perpendicular to the axis O2 of the axle 37 with respect to the axis O1 of the turning shaft 35, and the horizontal rotation axis O10 of the wheel 15, which is aligned in the horizontal direction and perpendicular to the axis O2 of the axle 37, is arranged perpendicular to the axis O2 of the turning shaft 35. Therefore, in the past (for example, Patent Document 1), the wheels were provided at positions offset by a predetermined distance in the direction along the axles from the axial centers of the first and second driving shafts, which serve as the turning shafts, so that when an external force is applied to the vehicle body in the horizontal direction without being driven by a drive device, the wheels do not smoothly turn around the turning shaft, making it difficult to change direction instantly. In this regard, with the drive wheel 120, due to the above-mentioned configuration, when a horizontal external force is applied without driving the wheel 15, the wheel 15 can smoothly turn about the axis center O1 of the turning shaft 35. As a result, the drive wheel 120 of the embodiment is provided with a differential omnidirectional movement mechanism, and can instantly change direction when the wheel 15 is not driven.

[0089] In the driving wheel 120 of the embodiment, the wheel 15 is made up of two wheels, and a vertical rotation axis O5 and a horizontal rotation axis O10 are present at the center between the wheels 15a, 15b.

[0090] With this drive wheel 120, when the wheel 15 is a dual wheel, the vertical rotation axis O5 of the wheel 15, which runs vertically and perpendicular to the axis O2 of the axle 37, can be shifted horizontally relative to the axis O1 of the pivot shaft 35, perpendicular to the axis O2 of the axle 37, and the horizontal rotation axis O10 of the wheel 15, which runs horizontally and perpendicular to the axis O2 of the axle 37, can be positioned perpendicular to the axis O2 of the pivot shaft 35, thereby achieving the effect of enabling instantaneous direction changes even when the wheel 15 is not driven.

[0091] Moreover, the dolly 100 of the embodiment includes the above-mentioned drive wheels 120 and the dolly body 101 to which the drive wheels 120 are attached. Therefore, the basic structure of the dolly 100 can be simplified.

[0092] [Variations] In the above-mentioned driving wheels 110, 120, the gear described as a spur gear may be, for example, a helical gear. In the above-mentioned driving wheels 110, 120, the gear described as a bevel gear may be, for example, a crown gear. In the above-mentioned driving wheels 110, 120, the wheel 15 may not be provided on the above-mentioned axle 37, but a separate shaft arranged parallel to the axle 37 may be provided separately from the axle 37, the wheel 15 may be provided on this separate shaft, and the axle 37 and the separate shaft may be configured to transmit rotational force by a winding transmission mechanism. Although not shown in the figure, the winding transmission mechanism is configured, for example, by providing a winding wheel on each of the axle 37 and the separate shaft, and wrapping an endless winding transmission member around each winding wheel. Each winding wheel is configured as a pulley, and the winding transmission member is configured as a timing belt. Alternatively, each winding wheel is configured as a sprocket, and the winding transmission member is configured as a chain. By configuring in this way, the offset relationship described above can also be achieved. [Explanation of symbols]

[0093] 13A First transmission mechanism 13B Second transmission mechanism 14A First power conversion mechanism 14B Second power conversion mechanism 15,15a,15b wheels 35 Swivel Axis 37 Axle 40A first output shaft 40B Second output shaft 41A First conversion drive gear 41B Second conversion drive gear 42 Transformation driven gear 100 Carts 101 Cart body 110,120 Drive wheels

Claims

1. A first input shaft and a second input shaft arranged coaxially; a first output shaft and a second output shaft arranged coaxially and parallel to the first input shaft and the second input shaft; an axle connected to the wheel; a pivot shaft that is arranged coaxially with the first input shaft and the second input shaft and supports the wheels rotatably via the axle; a first transmission mechanism that transmits a rotational force of the first input shaft to the first output shaft; a second transmission mechanism that transmits a rotational force of the second input shaft to the second output shaft; a first power conversion mechanism including a conversion driven gear provided together with the wheel and a first conversion drive gear meshing with the conversion driven gear and provided on the first output shaft; a second power conversion mechanism including the conversion driven gear and a second conversion drive gear that meshes with the conversion driven gear and is provided on the second output shaft; Including, The conversion driven gear is configured as a single gear and is used in common to the first power conversion mechanism and the second power conversion mechanism, and the vertical rotation axis of the wheel, which is perpendicular to the axis of the axle, is shifted horizontally relative to the axis of the pivot shaft, and the horizontal rotation axis of the wheel, which is parallel to the horizontal direction perpendicular to the axis of the axle, is disposed perpendicular to the axis of the pivot shaft. Drive wheel.

2. The wheel is composed of a single wheel, and the vertical rotation axis and the horizontal rotation axis exist on an equatorial plane of the wheel.

2. The drive wheel of claim 1.

3. The wheel is composed of a pair of wheels, and the vertical rotation axis and the horizontal rotation axis are located at the center between the wheels.

2. The drive wheel of claim 1.

4. Drive wheels and A carriage body to which the drive wheels are attached; Equipped with The drive wheels are A first input shaft and a second input shaft arranged coaxially; a first output shaft and a second output shaft arranged coaxially and parallel to the first input shaft and the second input shaft; an axle connected to the wheel; a pivot shaft that is arranged coaxially with the first input shaft and the second input shaft and supports the wheels rotatably via the axle; a first transmission mechanism that transmits a rotational force of the first input shaft to the first output shaft; a second transmission mechanism that transmits a rotational force of the second input shaft to the second output shaft; a first power conversion mechanism including a conversion driven gear provided together with the wheel and a first conversion drive tooth meshing with the conversion driven gear and provided on the first output shaft; a second power conversion mechanism including the conversion driven gear and a second conversion drive gear that meshes with the conversion driven gear and is provided on the second output shaft; Including, The conversion driven gear is configured as a single gear and is used in common to the first power conversion mechanism and the second power conversion mechanism, and the vertical rotation axis of the wheel, which is perpendicular to the axis of the axle, is shifted horizontally relative to the axis of the pivot shaft, and the horizontal rotation axis of the wheel, which is parallel to the horizontal direction perpendicular to the axis of the axle, is disposed perpendicular to the axis of the pivot shaft. Trolley.

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