Drive wheel and cart

Abstract

The present invention addresses the problem of how to provide a differential omnidirectional movement mechanism while simplifying the configuration thereof. A drive wheel 110 comprises: a first input shaft 25A and a second input shaft 25B disposed coaxially; a first output shaft 40A disposed on a different axis from that of the first input shaft 25A and the second input shaft 25B; a first transmission mechanism 13A including a first transmission drive gear 38A and a main transmission driven gear 39 in order to transmit the rotational force of the first input shaft 25A to the first output shaft 40A; a second transmission mechanism 13B that, in order to transmit the rotational force of the second input shaft 25B to the first output shaft 40A, includes a second transmission drive gear 38B having the same number of teeth as the first transmission drive gear 38A, a main transmission driven intermediate gear 39B for meshing with the second transmission drive gear 38B and thereby reversing the direction of rotation, and a main transmission driven gear 39; a freely rotatable main shaft 50 to which a wheel 15 is connected; a first conversion gear mechanism 14A for transmitting the rotational force of the first output shaft 40A to the main shaft 50; and a pivot shaft 35 that pivotally supports the wheel 15 via the main shaft 50.

Description

Drive wheels and bogies

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

[0002] Patent Document 1 discloses a drive wheel and a bogie using the drive wheel. The drive wheel includes a first input shaft and a second input shaft arranged coaxially, a first output shaft and a second output shaft arranged on separate axes, a first spur gear mechanism that transmits the rotational force of the first input shaft to the first output shaft, a second spur gear mechanism that transmits the rotational force of the second input shaft to the second output shaft, wheels connected to an axle, a turning shaft that rotatably supports the wheels via the axle, a first power conversion mechanism that transmits the rotational force of the first output shaft to one end of the axle, and a second power conversion mechanism that transmits the rotational force of the second output shaft to the other end of the axle.

[0003] Patent Document 2 discloses a steerable drive mechanism. This drive mechanism includes a rotatable steering unit, wheels supported by the steering unit, a driver that rotates around an axis on the center line of the steering unit, and an output shaft that is located eccentrically from the central axis of the steering unit and transmits rotational force obtained from the driver to the wheels. The driver is a driver that includes a first driver that is driven in a forward rotation direction and a second driver that is driven in a reverse rotation direction, which are arranged coaxially. The output shaft includes a first output section that receives driving force from the first driver and a second output section that receives driving force from a conversion section that converts the rotation of the second driver to a forward rotation direction. The output shaft is constrained by the first output section and the second output section and transmits the rotational force obtained from the output section to the wheels.

[0004] JP 2020-024033 A International Publication No. 2010 / 147100

[0005] The drive wheel described in Patent Document 1 and the drive mechanism described in Patent Document 2 include a differential omnidirectional movement mechanism. It is desirable to provide such a differential omnidirectional movement mechanism while simplifying its basic configuration as much as possible.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a drive wheel and a bogie that can simplify the basic configuration while being equipped with a differential omnidirectional movement mechanism.

[0007] In order to achieve the above-mentioned object, a drive wheel of one embodiment of the present disclosure comprises a first input shaft and a second input shaft arranged on the same axis, a first output shaft arranged on a different axis from the first input shaft and the second input shaft, a first transmission mechanism including a first transmission drive gear and a main transmission driven gear so as to transmit the rotational force of the first input shaft to the first output shaft, a second transmission mechanism including a second transmission drive gear having the same number of teeth as the first transmission drive gear so as to transmit the rotational force of the second input shaft to the first output shaft, a main transmission driven intermediate gear that meshes with the second transmission drive gear to reverse the direction of rotation, and the main transmission driven gear, a rotatable main shaft to which a wheel is connected, a first power conversion mechanism that transmits the rotational force of the first output shaft to the main shaft, and a turning shaft that supports the wheel so that it can turn via the main shaft.

[0008] In a preferred embodiment of the drive wheel, the wheel is fixed to the main shaft.

[0009] In a preferred embodiment of the drive wheels, each of the transmission mechanisms is constituted by a helical gear.Furthermore, in a preferred embodiment of the drive wheels, the second transmission mechanism includes an auxiliary main transmission driven intermediate gear which is a reverse-inclined helical gear that is coaxial with the main transmission driven intermediate gear, has the same pitch diameter and number of teeth as the main transmission driven intermediate gear, and an auxiliary main transmission driven gear which is a reverse-inclined helical gear that is coaxial with the main transmission driven gear, has the same pitch diameter and number of teeth as the main transmission driven gear.

[0010] In a preferred embodiment of the drive wheel, the drive wheel further includes a second output shaft separate from the first output shaft, a third transmission mechanism including the first transmission drive gear to transmit the rotational force of the first input shaft to the second output shaft, an auxiliary transmission driven intermediate gear that meshes with the first transmission drive gear to reverse the direction of rotation, and an auxiliary transmission driven gear, a fourth transmission mechanism including the second transmission drive gear and the auxiliary transmission driven gear to transmit the rotational force of the second input shaft to the second output shaft, and a second power conversion mechanism that transmits the rotational force of the second output shaft to the main shaft. Furthermore, as a desirable aspect of the above-mentioned drive wheel, the second transmission mechanism includes an auxiliary main transmission driven intermediate gear consisting of a reverse-inclined helical gear that is coaxial with the main transmission driven intermediate gear, has the same pitch diameter and the same number of teeth as the main transmission driven intermediate gear, and an auxiliary main transmission driven gear consisting of a reverse-inclined helical gear that is coaxial with the main transmission driven intermediate gear, has the same pitch diameter and the same number of teeth as the main transmission driven gear; and the third transmission mechanism includes an auxiliary auxiliary transmission driven intermediate gear consisting of a reverse-inclined helical gear that is coaxial with the auxiliary transmission driven intermediate gear, has the same pitch diameter and the same number of teeth as the main transmission driven gear, and an auxiliary auxiliary transmission driven gear consisting of a reverse-inclined helical gear that is coaxial with the main transmission driven gear, has the same pitch diameter and the same number of teeth as the main transmission driven gear.

[0011] In a preferred embodiment of the drive wheel, the rotation axis of the wheel, which runs vertically and intersects the axis of the main shaft, is shifted horizontally in a direction perpendicular to the axis of the main shaft relative to the axis of the pivot shaft.

[0012] A desirable aspect of the drive wheel includes an axle to which the wheel is fixed, and a torque transmission mechanism that transmits the torque of the main shaft to the axle, and the torque transmission mechanism displaces the rotation axis of the wheel, which runs vertically and intersects the axis of the axle, horizontally and perpendicularly to the axis of the axle, relative to the axis of the pivot shaft.Furthermore, a desirable aspect of the drive wheel includes the torque transmission mechanism being a belt transmission mechanism.

[0013] 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.

[0014] According to the present disclosure, it is possible to simplify the basic configuration while providing a differential omnidirectional movement mechanism.

[0015] FIG. 1 is a perspective view showing the basic configuration of a drive wheel of the first embodiment. FIG. 2 is a plan view showing the basic configuration of a drive wheel of the first embodiment. FIG. 3 is a right side view showing the basic configuration of a drive wheel of the first embodiment. FIG. 4 is a front view showing the basic configuration of a drive wheel of the first embodiment. FIG. 5 is a cross-sectional view showing a drive system of a drive wheel of the first embodiment. FIG. 6 is a cross-sectional view showing a drive system of a drive wheel of the first embodiment. FIG. 7 is a plan view showing a drive system of a drive wheel of the first embodiment. FIG. 8 is a plan view showing a drive system of a drive wheel of the first embodiment. FIG. 9 is a front view showing a drive system of a drive wheel of the first embodiment. FIG. 10 is a rear view showing a drive system of a drive wheel of the first embodiment. FIG. 11 is a schematic diagram showing a drive force transmission path of a drive wheel of the first embodiment. FIG. 12 is a front view showing the basic configuration of a drive wheel of the second embodiment. FIG. 13 is a cross-sectional view showing a drive system of a drive wheel of the second embodiment. FIG. 14 is a plan view showing a drive system of a drive wheel of the second embodiment. FIG. 15 is a plan view showing a drive system of a drive wheel of the second embodiment. FIG. 16 is a front view showing a drive system of a drive wheel of embodiment 2. FIG. 17 is a rear view showing a drive system of a drive wheel of embodiment 2. FIG. 18 is a schematic diagram showing a drive force transmission path of a drive wheel of embodiment 2. FIG. 19 is a front view showing a drive system of a drive wheel of embodiment 3. FIG. 20 is a rear view showing a drive system of a drive wheel of embodiment 3. FIG. 21 is a front view showing a drive system of a drive wheel of embodiment 4. FIG. 22 is a rear view showing a drive system of a drive wheel of embodiment 4. FIG. 23 is a perspective view showing a basic configuration of a drive wheel of embodiment 5. FIG. 24 is a front view showing the basic configuration of a drive wheel of embodiment 5. FIG. 25 is a right side view showing the basic configuration of a drive wheel of embodiment 5. FIG. 26 is a schematic diagram showing an example configuration of a bogie of an embodiment.

[0016] Preferred embodiments of the drive wheels and bogies 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 configurations that combine the embodiments. Furthermore, the components in the embodiments include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range.

[0017] FIG. 26 is a schematic diagram illustrating an example of the configuration of a carriage according to an embodiment.

[0018] The trolley 100 includes a trolley body 101 , a handle 102 , four drive wheels 110 ( 120 , 130 , 140 , 150 ), a power supply unit 104 , and a control device 105 .

[0019] The bogie 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 longitudinal side of the bogie body 101. Four drive wheels 110 are attached to the four corners of the back side of the bogie 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 back side of the bogie 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. Therefore, in the bogie 100, the control device 105 controls the drive wheels 110.

[0020] The cart body 101 has a flat surface, so that 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 such equipment include a hand lifter, a forklift, a picking robot, and medical equipment.

[0021] The bogie 100 and the equipment are not limited to the above-described configuration in terms of the number and arrangement of the drive wheels 110. For example, in the above-described four-wheel configuration, the bogie 100 and the equipment may have a pair of drive wheels 110 attached to the rear side of the bogie 100 and a pair of driven wheels attached to the front side of the bogie 100. Furthermore, although not explicitly shown in the drawings, in a configuration with three or more wheels, the bogie 100 and the equipment may have one drive wheel 110 and all the other wheels may be driven wheels. Furthermore, although not explicitly shown in the drawings, in a configuration with three or more wheels, the bogie 100 and the equipment 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 bogie 100 and the equipment may have at least one drive wheel 110.

[0022] [First Embodiment of Drive Wheel] The drive wheel 110 will now be described in detail. FIG. 1 is a perspective view showing the basic configuration of the drive wheel of the first embodiment. FIG. 2 is a plan view showing the basic configuration of the drive wheel of the first embodiment. FIG. 3 is a right side view showing the basic configuration of the drive wheel of the first embodiment. FIG. 4 is a partially cutaway front view showing the basic configuration of the drive wheel of the first embodiment. FIG. 5 is a cross-sectional view (cross-sectional view A-A in FIG. 4) showing the drive system of the drive wheel of the first embodiment. FIG. 6 is a cross-sectional view (cross-sectional view B-B in FIG. 3) showing the drive system of the drive wheel of the first embodiment. FIG. 7 is a plan view showing the drive system of the drive wheel of the first embodiment. FIG. 8 is a plan view showing the drive system of the drive wheel of the first embodiment. FIG. 9 is a front view showing the drive system of the drive wheel of the first embodiment. FIG. 10 is a rear view showing the drive system of the drive wheel of the first embodiment. FIG. 11 is a schematic diagram showing the drive force transmission path of the drive wheel of the first embodiment.

[0023] In the following description, of the first, second, and third directions that intersect with one another, the first direction will be referred to as the "front-rear direction X," the second direction will be referred to as the "width direction Y," and the third direction will be referred to as the "up-down direction Z." The front-rear direction X, width direction Y, and up-down direction Z are perpendicular to one another. The front-rear direction X typically corresponds to the direction along which the drive wheels 110 move straight.

[0024] 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 swivel section 12, a transmission mechanism 13, a power conversion mechanism 14, and wheels 15 are provided.

[0025] The main body 10 is formed in a plate shape with its plate surfaces facing up and down. The drive mechanism 11 inputs rotational force and is provided mainly above the main body 10. The swivel unit 12 is located mainly 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 rotatable by the rotational force input via the drive mechanism 11, the transmission mechanism 13, and the power conversion mechanism 14, and are steerable by the swivel unit 12.

[0026] The drive mechanism 11 includes 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 configured as 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 extends in the vertical direction parallel to the drive shaft 23Aa and is supported rotatably around an axis O1. The first driven pulley 26A is fixed to the 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 drive shaft 23Aa. The first drive 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 drive mechanism 22A, when the first drive unit 23A is driven, the first driving pulley 24A rotates, and this rotation is transmitted from the first driving pulley 24A to the first driven pulley 26A via the first drive belt 27A, thereby rotating the first input shaft 25A.

[0027] 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 configured with 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 with the same diameter as the first drive pulley 24A. The second input shaft 25B is provided extending in the vertical direction so as to be parallel to the drive shaft 23Ba, and is supported for rotation about an axis O1. The second input shaft 25B is cylindrical and passes through the first input shaft 25A. The second input shaft 25B is disposed outside the first input shaft 25A via a pair of intermediate bearings 44 (see FIG. 4 ) 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 has 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 drive pulley 24B are arranged side by side in a direction perpendicular to the second input shaft 25B and the drive shaft 23Ba. The second drive belt 27B is annular and is wound around the second driven pulley 26B and the second drive pulley 24B. Therefore, the second belt drive mechanism 22B drives the second drive unit 23B, causing the second drive pulley 24B to rotate, and this rotation is transmitted from the second drive pulley 24B via the second drive belt 27B to the second driven pulley 26B, causing the second input shaft 25B to rotate.

[0028] The swivel unit 12 includes a swivel shaft 35, a first support member 36A, and a second support member 36B. The swivel shaft 35 has an axis O1 at the center of its disk shape and is rotatably supported via a swivel bearing 45 (see FIG. 5 ) in a circular through-hole 10a that penetrates the main body 10 in the up-down direction. This allows the swivel shaft 35 to be supported rotatably relative to the main body 10 about the axis O1.

[0029] As shown in FIG. 5 , the pivot 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 the first input shaft 25A via a first input bearing 43. Therefore, the first input shaft 25A is supported rotatably relative to the pivot shaft 35 about the axis O1, and is also supported rotatably relative to the main body 10 about the axis O1. In other words, the pivot shaft 35 is rotatable relative to the main body 10 regardless of the rotation of the first input shaft 25A. Therefore, the drive wheel 110 of this embodiment can input rotational force to the first input shaft 25A on the axis O1, which is the pivot axis of the wheel 15. Furthermore, the pivot shaft 35 is disposed so as to rotatably support the second input shaft 25B of the second belt drive mechanism 22B facing upward, and rotatably supports the second input shaft 25B via a second input bearing 49. As described above, the second input shaft 25B passes through the first input shaft 25A and is rotatably disposed outside the first input shaft 25A via the intermediate bearing 44. Therefore, the second input shaft 25B is supported via the first input shaft 25A for relative rotation about the axis O1 with respect to the revolving shaft 35, and is also supported for relative rotation about the axis O1 with respect to the main body 10. In other words, the revolving shaft 35 is rotatable with respect to the main body 10 regardless of the rotation of the second input shaft 25B. Therefore, the drive wheel 110 of the embodiment can input rotational force to the second input shaft 25B, which is located 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 disposed coaxially along the axis O1.

[0030] The rotating shaft 35 is provided at the bottom of the disk shape with a first support member 36A and a second support member 36B extending downward on both sides of the wheel 15 in the width direction Y. The wheel 15 is integrally provided with a main shaft 50 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). One end of the main shaft 50 along the axis O2 is rotatably supported by the first support member 36A via a wheel bearing 48 (see FIG. 6 ), and the other end of the main shaft 50 along the axis O2 is rotatably supported by the second support member 36B via a wheel bearing 48.

[0031] 4 to 9 , the transmission mechanism 13 includes a first transmission gear mechanism (first transmission mechanism) 13A, a second transmission gear mechanism (second transmission mechanism) 13B, and a first output shaft 40A. The first transmission gear mechanism 13A includes a first transmission drive gear 38A and a main transmission driven gear 39. The second transmission gear mechanism 13B includes a second transmission drive gear 38B, a main transmission driven intermediate gear 39B, and the main transmission driven gear 39. In the driving wheel 110 of this embodiment, the first transmission gear mechanism 13A and the second transmission gear mechanism 13B are configured with spur gears.

[0032] In the first transmission gear mechanism 13A, the first transmission drive gear 38A and the main transmission driven gear 39 are housed in the housing portion 35a, as shown in FIGS. 5 and 6 . The first transmission drive gear 38A is fixed to the first input shaft 25A. The first input shaft 25A is provided to penetrate the revolving shaft 35, and the first transmission drive gear 38A is fixed inside the housing portion 35a. The first input shaft 25A is also provided to penetrate the revolving shaft 35 in the vertical direction along the axis O1 and is rotatably supported in the housing portion 35a via a first input bearing 43. Therefore, the first transmission drive gear 38A rotates around the axis O1. The first transmission drive gear 38A meshes with the main transmission driven gear 39. The main transmission driven gear 39 is fixed to the first output shaft 40A. A portion of the first output shaft 40A is disposed in the housing portion 35a, and another portion protrudes below the revolving shaft 35. The first output shaft 40A is supported by the rotary shaft 35 via a pair of first output bearings 46 (see FIG. 6), and is supported so as to be rotatable about an axis O3 parallel to the axis O1.

[0033] In the second transmission gear mechanism 13B, the second transmission drive gear 38B, the main transmission driven intermediate gear 39B, and the main transmission driven gear 39 are housed in the housing portion 35a, as shown in FIGS. 5 and 6 . The second transmission drive gear 38B is fixed to the second input shaft 25B. A portion of the second input shaft 25B fits into the housing portion 35a along the axis O1, and the second transmission drive gear 38B is fixed in the housing portion 35a. As described above, the second input shaft 25B is disposed outside the first input shaft 25A via a pair of intermediate bearings 44 and is supported rotatably about the axis O1. As described above, the second input shaft 25B is rotatably supported on the pivot shaft 35 via the second input bearing 49. Therefore, the second transmission drive gear 38B rotates about the axis O1.

[0034] The main transmission driven intermediate gear 39B meshes with the second transmission drive gear 38B. The main transmission driven intermediate gear 39B is supported in the accommodation portion 35a via an intermediate gear bearing 52, and is supported rotatably about an axis O6 parallel to the axis O1. The main transmission driven intermediate gear 39B also meshes with the main transmission driven gear 39. Therefore, the main transmission driven gear 39 is used in common in the configurations of the first transmission gear mechanism 13A and the second transmission gear mechanism 13B.

[0035] In this transmission mechanism 13, the first transmission drive gear 38A of the first transmission gear mechanism 13A and the second transmission drive gear 38B of the second transmission gear mechanism 13B have the same pitch circle diameter and the same number of teeth.

[0036] 6, 9, and 10, the power conversion mechanism 14 has a first conversion gear mechanism (first power conversion mechanism) 14A. The first conversion gear mechanism 14A is composed of a first conversion drive gear 41A and a first conversion driven gear 42A. In the driving wheel 110 of this embodiment, the first conversion gear mechanism 14A is composed of a bevel gear.

[0037] The first conversion drive gear 41A is fixed to the lower part of the first output shaft 40A. Therefore, the first conversion drive gear 41A rotates around the axis O3 together with the first output shaft 40A. Furthermore, the first conversion driven gear 42A is fixed to one end of the main shaft 50. Therefore, the first conversion driven gear 42A rotates around the axis O2 together with the main shaft 50. The first conversion drive gear 41A meshes with the first conversion driven gear 42A. Therefore, the first conversion gear mechanism 14A converts the rotation of the first output shaft 40A around the axis O3 into rotation of the main shaft 50 around the axis O2.

[0038] 7 and 8, in the drive wheel 110 of the embodiment, the rotation axis O5 of the wheel 15, which is aligned along the vertical direction intersecting the axis O2 of the main shaft 50, is offset from the axis O1 of the turning shaft 35 in the horizontal direction (front-rear direction X) perpendicular to the axis O2 of the main shaft 50. This allows the vertical size of the drive wheel 110 to be made compact. In addition, in the drive wheel 110 of the embodiment, the axis O3 of the first output shaft 40A is arranged to overlap the axis O2 of the main shaft 50 in a plan view. This ensures that force is transmitted to the main shaft 50.

[0039] The drive wheel 110 can rotate and steer the wheels 15 by rotating the first input shaft 25A and the second input shaft 25B using the drive mechanism 11. For example, 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 by making the number of rotations (rotational speed) transmitted to the first output shaft 40A the same, the wheels 15 can be rotated without being steered. In this case, by making the number of rotations (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.

[0040] The operation of the drive wheel 110 will now be described with reference to FIG. 11 . For ease of explanation, the first transmission drive gear 38A and the second transmission drive gear 38B have different diameters in FIG. 11 . However, as described above, they have the same diameter and number of teeth. As shown in FIG. 11 , when the first input shaft 25A of the drive wheel 110 rotates in the A1 direction, the first transmission drive gear 38A rotates in the same direction, and the main transmission driven gear 39 meshing with the first transmission drive gear 38A rotates in the C direction. When the main transmission driven gear 39 rotates in the C direction, the first conversion drive gear 41A, which is integral with the main transmission driven gear 39 via the first output shaft 40A, rotates in the same direction. Then, the first conversion driven gear 42A meshing with the first conversion drive gear 41A rotates in the D direction, causing the main shaft 50, which is integral with the first conversion driven gear 42A, to rotate in the same direction. 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 transmission drive gear 38B rotates in the same direction, and the main transmission driven intermediate gear 39B meshing with the second transmission drive gear 38B rotates in the B2 direction. When the main transmission driven intermediate gear 39B rotates in the B2 direction, the main transmission driven gear 39 meshing with the main transmission driven intermediate gear 39B rotates in the C direction. Then, as a result of the main transmission driven gear 39 rotating in the C direction, the first conversion drive gear 41A, which is provided integrally via the first output shaft 40A, rotates in the same direction, and the first conversion driven gear 42A meshing with the first conversion drive gear 41A rotates in the D direction, causing the main shaft 50, which is integral with the first conversion driven gear 42A, to rotate in the same direction.

[0041] 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 main transmission driven intermediate gear 39B to the main transmission driven gear 39 of the drive wheels 110 becomes lower than the rotation speed input from the first transmission drive gear 38A to the main transmission driven gear 39. Then, in order to absorb the difference in rotation speed, the swivel shaft 35 rotates by the rotation speed difference, turning and steering the wheels 15. Furthermore, when the rotation of the first input shaft 25A or the second input shaft 25B is stopped, the rotation speed input from the first transmission drive gear 38A to the main transmission driven gear 39 or the rotation speed input from the main transmission driven intermediate gear 39B to the main transmission driven gear 39 becomes zero, and the wheels 15 do not rotate, and the swivel shaft 35 turns and steers.

[0042] As shown in FIG. 11 , the drive wheel 110 of the above-described embodiment rotates the coaxially arranged first input shaft 25A and second input shaft 25B in opposite directions (A1 direction and B1 direction), respectively, and transmits these rotations to the main transmission driven gear 39 provided on the first output shaft 40A in the same direction (C direction). To do this, a main transmission driven intermediate gear 39B is provided that reverses the rotation (B1 direction) of the second transmission drive gear 38B (B2 direction). If an odd number of main transmission driven intermediate gears 39B are engaged between the second transmission drive gear 38B and the main transmission driven gear 39, the rotation (B1 direction) of the second transmission drive gear 38B can be reversed (B2 direction) and then transmitted to the main transmission driven gear 39 in the same direction (C direction). Therefore, although the above-described embodiment has been described as including one main transmission driven intermediate gear 39B, there may be multiple main transmission driven intermediate gears 39B as long as there is an odd number of them.

[0043] Although not shown in the drawings, the drive wheel 110 of the embodiment has a swivel position detector. The swivel position detector is provided on the main body 10 and detects the rotation position of the swivel shaft 35, i.e., the rotation position of the swivel unit 12 relative to the main body 10. A detection signal from the detector is input to the control device 105 of the bogie (equipment) 100. As a result, the control device 105 can control the rotation of the drive wheel 110.

[0044] The driving wheel 110 of the embodiment includes a first input shaft 25A and a second input shaft 25B that are arranged coaxially, a first output shaft 40A that is arranged on a different axis from the first input shaft 25A and the second input shaft 25B, a first transmission gear mechanism (first transmission mechanism) 13A that includes a first transmission drive gear 38A and a main transmission driven gear 39 so as to transmit the rotational force of the first input shaft 25A to the first output shaft 40A, and a first transmission drive gear 38A that transmits the rotational force of the second input shaft 25B to the first output shaft 40A. a second transmission drive gear 38B having the same number of teeth as the first output shaft 40A, a main transmission driven intermediate gear 39B that meshes with the second transmission drive gear 38B to reverse the direction of rotation, and a second transmission gear mechanism (second transmission mechanism) 13B that includes the main transmission driven gear 39; a rotatable main shaft 50 to which the wheels 15 are connected; a first conversion gear mechanism (first power conversion mechanism) 14A that transmits the rotational force of the first output shaft 40A to the main shaft 50; and a swivel shaft 35 that rotatably supports the wheels 15 via the main shaft 50.

[0045] The drive wheel 110 has a differential omnidirectional movement mechanism. That is, in the drive wheel 110, the rotational force of the first input shaft 25A is transmitted to the first output shaft 40A via the first transmission gear mechanism 13A, the rotational force of the second input shaft 25B is transmitted to the first output shaft 40A via the second transmission gear mechanism 13B, and the rotational force is transmitted from the first output shaft 40A to the main shaft 50 via the first conversion gear mechanism 14A. The drive wheel 110 can switch between the rotation of the wheels 15 connected to the main shaft 50 and the steering of the wheels 15 by adjusting the rotation speeds of the first input shaft 25A and the second input shaft 25B.

[0046] In particular, the drive wheel 110 transmits the rotational force of the first input shaft 25A and the second input shaft 25B to the first output shaft 40A. Furthermore, the drive wheel 110 transmits the rotational force transmitted to the first output shaft 40A by the first conversion gear mechanism 14A to the main shaft 50. Therefore, in the prior art (for example, Patent Document 1), the rotational force of the first input shaft is transmitted to the first output shaft via a first transmission mechanism, and the rotational force of the second input shaft is transmitted to the second output shaft via a second transmission mechanism, but the drive wheel 110 is configured so that the rotational force of both the first input shaft 25A and the second input shaft 25B is transmitted to the first output shaft 40A. Furthermore, in a conventional example (e.g., Patent Document 1), the rotational force of the first output shaft is transmitted to the wheel axle via a first power conversion mechanism, and the rotational force of the second output shaft is transmitted to the wheel axle via a second power conversion mechanism. However, in the drive wheel 110, the rotational force of the first output shaft 40A, which is transmitted in both directions, is transmitted to the main shaft 50 via a single first conversion gear mechanism 14A. As a result, the drive wheel 110 of the embodiment can have a simplified basic configuration. Furthermore, while a conventional example (e.g., Patent Document 2) includes a first output section and a second output section, in the drive wheel 110, both the first transmission gear mechanism 13A and the second transmission gear mechanism 13B include a main transmission driven gear 39, and the same functions as the conventional first output section and second output section are achieved with a single main transmission driven gear 39. This reduces the costs of parts procurement and assembly, and the failure rate can be reduced by reducing the number of parts.

[0047] In addition, in this drive wheel 110, the wheel 15 is fixed to the main shaft 50.

[0048] According to this driving wheel 110, the wheel 15 is rotated by the main shaft 50 to which rotational force is transmitted by the first conversion gear mechanism 14A, so that the basic configuration can be simplified.

[0049] In addition, in this drive wheel 110, the rotation axis O5 of the wheel 15, which intersects the axis O2 of the main shaft 50 and runs vertically, is positioned offset horizontally from the axis O1 of the turning shaft 35, perpendicular to the axis O2 of the main shaft 50.

[0050] With this drive wheel 110, when the wheel 15 is not driven, the wheel 15 can passively turn by an external force acting from the horizontal direction. In other words, the cart 100 can be automatically driven and steered, and can also be manually driven and steered by an operator.

[0051] Moreover, the bogie 100 of the embodiment includes the above-described drive wheels 110 and the bogie body 101 to which the drive wheels 110 are attached. Therefore, the basic structure of the bogie 100 can be simplified.

[0052] [Embodiment 2 of Drive Wheel] Fig. 12 is a partially cutaway front view showing the basic configuration of a drive wheel of embodiment 2. Fig. 13 is a cross-sectional view (corresponding to the cross-sectional position B-B in Fig. 3) showing the drive system of the drive wheel of embodiment 2. Fig. 14 is a plan view showing the drive system of the drive wheel of embodiment 2. Fig. 15 is a plan view showing the drive system of the drive wheel of embodiment 2. Fig. 16 is a front view showing the drive system of the drive wheel of embodiment 2. Fig. 17 is a rear view showing the drive system of the drive wheel of embodiment 2. Fig. 18 is a schematic diagram showing the drive force transmission path of the drive wheel of embodiment 2.

[0053] The driving wheel 120 of the second embodiment differs from the driving wheel 110 of the first embodiment described above mainly in that the transmission mechanism 13 further includes a third transmission gear mechanism (third transmission mechanism) 13C, a fourth transmission gear mechanism (fourth transmission mechanism) 13D, and a second output shaft 40B, and the power conversion mechanism 14 further includes a second conversion gear mechanism (second power conversion mechanism) 14B. In the following description of the driving wheel 120 of the second embodiment, parts equivalent to those of the driving wheel 110 described above are designated by the same reference numerals, and description thereof will be omitted.

[0054] The third transmission gear mechanism 13C includes a first transmission drive gear 38A, an auxiliary transmission driven intermediate gear 39A, and an auxiliary transmission driven gear 39'. The fourth transmission gear mechanism 13D includes a second transmission drive gear 38B and the auxiliary transmission driven gear 39'. In the driving wheel 120 of this embodiment, like the first transmission gear mechanism 13A and the second transmission gear mechanism 13B of the driving wheel 110, the third transmission gear mechanism 13C and the fourth transmission gear mechanism 13D are configured with spur gears.

[0055] In the third transmission gear mechanism 13C, the first transmission drive gear 38A has the same configuration as the drive wheel 110 and is fixed to the first input shaft 25A. The sub-transmission driven intermediate gear 39A and the sub-transmission driven gear 39' are housed in the housing portion 35a, as shown in FIG. 13. The sub-transmission driven intermediate gear 39A meshes with the first transmission drive gear 38A, as shown in FIG. 14. The sub-transmission driven intermediate gear 39A is supported in the housing portion 35a via an intermediate gear bearing 54 and is supported rotatably about an axis O7 parallel to the axis O1. The sub-transmission driven gear 39' is fixed to the second output shaft 40B. A portion of the second output shaft 40B is disposed in the housing portion 35a, and another portion protrudes below the revolving shaft 35. The second output shaft 40B is supported by the rotating shaft 35 via a pair of second output bearings 53 (see FIG. 13), and is supported rotatably about an axis O4 parallel to the axis O1. The secondary transmission driven gear 39′ meshes with the secondary transmission driven intermediate gear 39A.

[0056] In the fourth transmission gear mechanism 13D, the second transmission drive gear 38B has the same configuration as the drive wheel 110 and is fixed to the second input shaft 25B. As shown in Fig. 15, the second transmission drive gear 38B also meshes with the secondary transmission driven gear 39'. Therefore, the secondary transmission driven gear 39' is used in common in the configurations of the third transmission gear mechanism 13C and the fourth transmission gear mechanism 13D.

[0057] In this transmission mechanism 13, similar to the drive wheel 110, the first transmission drive gear 38A and the second transmission drive gear 38B have the same pitch circle diameter and the same number of teeth. The main transmission driven gear 39 and the sub transmission driven gear 39' also have the same pitch circle diameter and the same number of teeth. The main transmission driven intermediate gear 39B and the sub transmission driven intermediate gear 39A also have the same pitch circle diameter and the same number of teeth.

[0058] 12, 13, 16, and 17, the second conversion gear mechanism 14B is composed of a second conversion drive gear 41B and a second conversion driven gear 42B. In the driving wheel 120 of the embodiment, the second conversion gear mechanism 14B is composed of a bevel gear, similar to the first conversion gear mechanism 14A of the driving wheel 110.

[0059] The second conversion drive gear 41B is fixed to the lower part of the second output shaft 40B. Therefore, the second conversion drive gear 41B rotates around the axis O4 together with the second output shaft 40B. In addition, the second conversion driven gear 42B is fixed to the other end of the main shaft 50. Therefore, the second conversion driven gear 42B rotates around the axis O2 together with the main shaft 50. The second conversion drive gear 41B meshes with the second conversion driven gear 42B. Therefore, the second conversion gear mechanism 14B converts the rotation of the second output shaft 40B around the axis O4 into rotation of the main shaft 50 around the axis O2.

[0060] 14 and 15 , the drive wheel 120 of the embodiment is disposed such that the rotational axis O5 of the wheel 15, which is aligned in the vertical direction intersecting the axis O2 of the main shaft 50, is offset in the horizontal direction (front-rear direction X) perpendicular to the axis O2 of the main shaft 50 with respect to the axis O1 of the turning shaft 35. Furthermore, the drive wheel 120 of the embodiment is disposed such that the axis O3 of the first output shaft 40A and the axis O4 of the second output shaft 40B overlap the axis O2 of the main shaft 50 in a plan view.

[0061] In this power conversion mechanism 14, the first conversion drive gear 41A and the second conversion drive gear 41B have the same pitch circle diameter and the same number of teeth. Also, the first conversion driven gear 42A and the second conversion driven gear 42B have the same pitch circle diameter and the same number of teeth.

[0062] The drive mechanism 11 rotates the first input shaft 25A and the second input shaft 25B of the drive wheels 120, thereby rotating and steering the wheels 15. For example, 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 by making the number of rotations (rotational speed) transmitted to the first output shaft 40A and the second output shaft 40B the same, the wheels 15 can be rotated without being steered. In this case, by making the number of rotations (rotational speed) of the first input shaft 25A and the second input shaft 25B different, the wheels 15 can be steered while rotating or stopped.

[0063] Here, the operation of the drive wheel 120 will be described. As shown in FIG. 18 , when the first input shaft 25A of the drive wheel 120 rotates in the A1 direction, the first transmission drive gear 38A rotates in the same direction, and the main transmission driven gear 39 meshing with the first transmission drive gear 38A rotates in the C direction. When the main transmission driven gear 39 rotates in the C direction, the first conversion drive gear 41A, which is integrally provided with the main transmission driven gear 39 via the first output shaft 40A, rotates in the same direction. Then, the first conversion driven gear 42A meshing with the first conversion drive gear 41A rotates in the D direction, causing the main shaft 50, which is integral with the first conversion driven gear 42A, to rotate in the same direction. On the other hand, when the second input shaft 25B of the drive wheel 120 rotates in the B1 direction, which is opposite to the A1 direction, the second transmission drive gear 38B rotates in the same direction, and the main transmission driven intermediate gear 39B meshing with the second transmission drive gear 38B rotates in the B2 direction. When the main transmission driven intermediate gear 39B rotates in the direction B2, the main transmission driven gear 39 meshing with the main transmission driven intermediate gear 39B rotates in the direction C. Then, as a result of the main transmission driven gear 39 rotating in the direction C, the first conversion drive gear 41A, which is provided integrally with the first output shaft 40A via the first output shaft 40A, rotates in the same direction, and the first conversion driven gear 42A meshing with the first conversion drive gear 41A rotates in the direction D, causing the main shaft 50, which is integral with the first conversion driven gear 42A, to rotate in the same direction.

[0064] Furthermore, when the first input shaft 25A of the drive wheel 120 rotates in the A1 direction, the first transmission drive gear 38A rotates in the same direction, and the secondary transmission driven intermediate gear 39A meshing with the first transmission drive gear 38A rotates in the A2 direction. When the secondary transmission driven intermediate gear 39A rotates in the A2 direction, the secondary transmission driven gear 39' meshing with the secondary transmission driven intermediate gear 39A rotates in the C' direction, which is opposite to the C direction. When the secondary transmission driven gear 39' rotates in the C' direction, the second conversion drive gear 41B, which is integral with the secondary transmission driven gear 39' via the second output shaft 40B, rotates in the same direction. Then, the second conversion driven gear 42B meshing with the second conversion drive gear 41B rotates in the D' direction, which is the same direction as the D direction, causing the main shaft 50, which is integral with the second conversion driven gear 42B, to rotate in the same direction. 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 transmission drive gear 38B rotates in the same direction, and the secondary transmission driven gear 39' meshing with the second transmission drive gear 38B rotates in the C' direction. Then, as a result of the secondary transmission driven gear 39' rotating in the C' direction, the second conversion drive gear 41B, which is provided integrally via the second output shaft 40B, rotates in the same direction, and the second conversion driven gear 42B meshing with the second conversion drive gear 41B rotates in the D' direction, causing the main shaft 50, which is integral with the second conversion driven gear 42B, to rotate in the same direction.

[0065] 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 main transmission driven intermediate gear 39B to the main transmission driven gear 39 and the rotation speed input from the second transmission drive gear 38B to the secondary transmission driven gear 39' become lower than the rotation speed input from the first transmission drive gear 38A to the main transmission driven gear 39 and the rotation speed input from the secondary transmission driven intermediate gear 39A to the secondary transmission driven gear 39'. Then, the turning shaft 35 rotates by the rotation speed difference, turning and steering the wheels 15. Furthermore, when the rotation of the first input shaft 25A or the second input shaft 25B is stopped, the rotation speed input to the main transmission driven gear 39 and the rotation speed input to the secondary transmission driven gear 39' become zero, and the wheels 15 turn and steer without rotating.

[0066] As shown in FIG. 18 , the drive wheel 120 in the above-described embodiment rotates the coaxially arranged first input shaft 25A and second input shaft 25B in opposite directions (A1 direction and B1 direction), respectively, and transmits these rotations to the main transmission driven gear 39 provided on the first output shaft 40A in the same direction (C direction). To do this, a main transmission driven intermediate gear 39B is provided that reverses the rotation (B1 direction) of the second transmission drive gear 38B (B2 direction). If an odd number of main transmission driven intermediate gears 39B are engaged between the second transmission drive gear 38B and the main transmission driven gear 39, the rotation (B1 direction) of the second transmission drive gear 38B can be reversed (B2 direction) and then transmitted to the main transmission driven gear 39 in the same direction (C direction). Therefore, although the above-described embodiment has been described as including one main transmission driven intermediate gear 39B, there may be multiple main transmission driven intermediate gears 39B as long as there is an odd number of them. Furthermore, as shown in FIG. 18 , the drive wheel 120 in the above-described embodiment is provided with an auxiliary transmission driven intermediate gear 39A that reverses the rotation (A1 direction) of the first transmission drive gear 38A (A2 direction) in order to rotate the coaxially arranged first input shaft 25A and second input shaft 25B in opposite directions (A1 direction and B1 direction), and transmits these rotations to the auxiliary transmission driven gear 39′ provided on the second output shaft 40B in the same direction (C′ direction). If an odd number of auxiliary transmission driven intermediate gears 39A are engaged between the first transmission drive gear 38A and the auxiliary transmission driven gear 39′, the rotation (A1 direction) of the first transmission drive gear 38A can be reversed (A2 direction) and then transmitted to the auxiliary transmission driven gear 39′ in the same direction (C′ direction). Therefore, although the above-described embodiment has been described as including only one auxiliary transmission driven intermediate gear 39A, there may be multiple auxiliary transmission driven intermediate gears 39A as long as there is an odd number of them.

[0067] The drive wheel 120 of the embodiment includes a first input shaft 25A and a second input shaft 25B arranged coaxially, a first output shaft 40A arranged on a different axis from the first input shaft 25A and the second input shaft 25B, a first transmission mechanism 13A including a first transmission drive gear 38A and a main transmission driven gear 39 to transmit the rotational force of the first input shaft 25A to the first output shaft 40A, a second transmission drive gear 38B having the same number of teeth as the first transmission drive gear 38A to transmit the rotational force of the second input shaft 25B to the first output shaft 40A, a main transmission driven intermediate gear 39B that meshes with the second transmission drive gear 38B to reverse the direction of rotation, and the main transmission driven gear 39, a rotatable main shaft 50 to which the wheel 15 is connected, a first conversion gear mechanism (first power conversion mechanism) 14A that transmits the rotational force of the first output shaft 40A to the main shaft 50, and a turning shaft 35 that rotatably supports the wheel 15 via the main shaft 50.

[0068] Furthermore, the drive wheel 120 of the embodiment further includes a second output shaft 40B on a separate axis from the first output shaft 40A, a third transmission gear mechanism 13C including a first transmission drive gear 38A to transmit the rotational force of the first input shaft 25A to the second output shaft 40B, an auxiliary transmission driven intermediate gear 39A and an auxiliary transmission driven gear 39' that mesh with the first transmission drive gear 38A to reverse the direction of rotation, a fourth transmission gear mechanism 13D including a second transmission drive gear 38B and an auxiliary transmission driven gear 39' to transmit the rotational force of the second input shaft 25B to the second output shaft 40B, and a second power conversion mechanism 14B that transmits the rotational force of the second output shaft 40B to the main shaft 50.

[0069] The drive wheel 120 has a differential omnidirectional movement mechanism. That is, in the drive wheel 120, the rotational force of the first input shaft 25A is transmitted to the first output shaft 40A via the first transmission gear mechanism 13A, the rotational force of the second input shaft 25B is transmitted to the first output shaft 40A via the second transmission gear mechanism 13B, and then transmitted from the first output shaft 40A to the main shaft 50 via the first conversion gear mechanism 14A. Furthermore, in the drive wheel 120, the rotational force of the first input shaft 25A is transmitted to the second output shaft 40B via the third transmission gear mechanism 13C, the rotational force of the second input shaft 25B is transmitted to the second output shaft 40B via the fourth transmission gear mechanism 13D, and then transmitted from the second output shaft 40B to the main shaft 50 via the second conversion gear mechanism 14B. The drive wheel 110 can switch between the rotation of the wheels 15 connected to the main shaft 50 and the steering of the wheels 15 by adjusting the rotation speeds of the first input shaft 25A and the second input shaft 25B.

[0070] In particular, in the drive wheel 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. Furthermore, in the drive wheel 120, the first conversion gear mechanism 14A transmits the rotational force of the first output shaft 40A to the main shaft 50, and the second conversion gear mechanism 14B transmits the rotational force of the second output shaft 40B to the main shaft 50. Therefore, the drive wheel 120 has a simplified basic configuration like the drive wheel 110, while being able to increase the transmission capacity from the first output shaft 40A and the second output shaft 40B to the main shaft 50.

[0071] In addition, in this drive wheel 120 , the wheel 15 is fixed to the main shaft 50 .

[0072] According to this driving wheel 120, the wheel 15 is rotated by the main shaft 50 to which rotational force is transmitted by the first conversion gear mechanism 14A and the second conversion gear mechanism 14B, so that the transmission capacity can be increased.

[0073] In addition, in this drive wheel 120, the rotation axis O5 of the wheel 15, which intersects the axis O2 of the main shaft 50 and runs vertically, is positioned offset horizontally from the axis O1 of the turning shaft 35, perpendicular to the axis O2 of the main shaft 50.

[0074] With this drive wheel 120, when the wheel 15 is not driven, the wheel 15 can passively turn by an external force acting from the horizontal direction. In other words, the cart 100 can be automatically driven and steered, and can also be manually driven and steered by an operator.

[0075] Moreover, the bogie 100 of the embodiment includes the above-described drive wheels 120 and the bogie body 101 to which the drive wheels 120 are attached. Therefore, the basic structure of the bogie 100 can be simplified.

[0076] [Third embodiment of drive wheels] Fig. 19 is a front view showing a drive system of a drive wheel according to a third embodiment. Fig. 20 is a rear view showing a drive system of a drive wheel according to the third embodiment.

[0077] The driving wheel 130 of the third embodiment differs from the above-described driving wheels 110 and 120 mainly in that the first transmission gear mechanism 13A and the second transmission gear mechanism 13B are configured with helical gears. In the following description of the driving wheel 130 of the third embodiment, parts equivalent to those of the above-described driving wheels 110 and 120 are designated by the same reference numerals, and description thereof will be omitted.

[0078] 19 and 20, in the first transmission gear mechanism 13A, the first transmission drive gear 38A and the main transmission driven gear 39 are configured as meshing helical gears. In the second transmission gear mechanism 13B, the second transmission drive gear 38B, the main transmission driven intermediate gear 39B, and the main transmission driven gear 39 are configured as meshing helical gears.

[0079] Other forms of the drive wheel 130, although not explicitly shown in the figures, include those in which, compared to the drive wheel 120 of embodiment 2, in the third transmission gear mechanism 13C, the first transmission drive gear 38A, the secondary transmission driven intermediate gear 39A, and the secondary transmission driven gear 39' are configured as meshing helical gears, and in the fourth transmission gear mechanism 13D, the second transmission drive gear 38B and the above-mentioned secondary transmission driven gear 39' are configured as meshing helical gears.

[0080] In the driving wheel 130 of this embodiment, the first transmission gear mechanism 13A, the second transmission gear mechanism 13B, the third transmission gear mechanism 13C, and the fourth transmission gear mechanism 13D are configured with helical gears.

[0081] In comparison with the above-mentioned drive wheels 110 and 120, which use spur gears in the transmission mechanism 13, this drive wheel 130 uses helical gears in the transmission mechanism 13, which improves the meshing ratio (smoother meshing), improves strength (surface pressure strength), and improves quietness, thereby achieving good gear meshing.

[0082] In addition, in this drive wheel 130, the wheel 15 is fixed to the main shaft 50.

[0083] With this drive wheel 130, the wheel 15 is rotated by the main shaft 50 to which rotational force is transmitted by the first conversion gear mechanism 14A, thereby simplifying the basic configuration and improving the meshing of the gears of the transmission mechanism 13.

[0084] In addition, in this drive wheel 130, the rotation axis O5 of the wheel 15, which intersects the axis O2 of the main shaft 50 and runs vertically, is positioned offset horizontally from the axis O1 of the turning shaft 35, perpendicular to the axis O2 of the main shaft 50.

[0085] With this drive wheel 130, when the wheel 15 is not driven, the wheel 15 can passively turn by an external force acting from the horizontal direction. In other words, the cart 100 can be automatically driven and steered, and can also be manually driven and steered by an operator.

[0086] Moreover, the bogie 100 of the embodiment includes the above-described drive wheels 130 and the bogie body 101 to which the drive wheels 130 are attached. Therefore, the basic structure of the bogie 100 can be simplified and good gear meshing can be achieved.

[0087] [Fourth embodiment of drive wheels] Fig. 21 is a front view showing a drive system of a drive wheel according to a fourth embodiment. Fig. 22 is a rear view showing a drive system of a drive wheel according to the fourth embodiment.

[0088] The driving wheel 140 of the fourth embodiment differs from the driving wheel 130 described above mainly in the configuration of the second transmission gear mechanism 13B. The driving wheel 140 of the fourth embodiment also differs from the driving wheel 130 of the third embodiment mainly in the configuration of the third transmission gear mechanism 13C. In the following description of the driving wheel 140 of the fourth embodiment, parts equivalent to those of the driving wheels 110, 120, and 130 described above are designated by the same reference numerals, and description thereof will be omitted.

[0089] As shown in Figures 21 and 22, the second transmission gear mechanism 13B transmits the rotational force of the first input shaft 25A to the first output shaft 40A, and is composed of a second transmission drive gear 38B, a main transmission driven intermediate gear 39B, an auxiliary transmission driven intermediate gear 391B, an auxiliary main transmission driven gear 391, and a main transmission driven gear 39.

[0090] The second transmission drive gear 38B, the main transmission driven intermediate gear 39B, and the main transmission driven gear 39 are configured as helical gears that mesh with each other in the same manner as the drive wheel 120.

[0091] The auxiliary transmission driven intermediate gear 391B is supported coaxially with the main transmission driven intermediate gear 39B and rotatably about the axis O6 together with the main transmission driven intermediate gear 39B. The auxiliary transmission driven intermediate gear 391B is a reverse-inclined helical gear that has the same pitch circle diameter and the same number of teeth as the main transmission driven intermediate gear 39B.

[0092] The auxiliary main transmission driven gear 391 is fixed to the first output shaft 40A coaxially with the main transmission driven gear 39 and is supported so as to be rotatable about the axis O3. The auxiliary main transmission driven gear 391 is a reverse-inclined helical gear that has the same pitch circle diameter and the same number of teeth as the main transmission driven gear 39. The auxiliary main transmission driven gear 391 meshes with an auxiliary transmission driven intermediate gear 391B.

[0093] That is, in the second transmission gear mechanism 13B, the rotational force of the second input shaft 25B is transmitted from the second transmission drive gear 38B to the first output shaft 40A via the main transmission driven intermediate gear 39B and the main transmission driven gear 39. Furthermore, in the second transmission gear mechanism 13B, the rotational force of the second input shaft 25B is transmitted from the auxiliary transmission driven intermediate gear 391B to the first output shaft 40A via the auxiliary main transmission driven gear 391.

[0094] Therefore, in the drive wheel 130 of the third embodiment described above, the meshing of the second transmission drive gear 38B, the main transmission driven intermediate gear 39B, and the main transmission driven gear 39, which are helical gears, can be favorably performed, but a load is generated in the thrust direction (direction along the axis). In this regard, the drive wheel 140 is provided with the auxiliary transmission driven intermediate gear 391B and the auxiliary main transmission driven gear 391, which are reverse-inclined helical gears, so that the load in the thrust direction can be offset and reduced.

[0095] As another form of the drive wheel 140, although not explicitly shown in the figures, the third transmission gear mechanism 13C may include an auxiliary auxiliary transmission driven intermediate gear and an auxiliary auxiliary transmission driven gear, which are helical gears, in place of the first transmission drive gear 38A, the auxiliary transmission driven intermediate gear 39A, and the auxiliary transmission driven gear 39', which are helical gears, in comparison with the drive wheel 130 of embodiment 3.

[0096] The auxiliary secondary transmission driven intermediate gear is supported coaxially with the auxiliary transmission driven intermediate gear 39A and rotatably about the axis O7 together with the auxiliary transmission driven intermediate gear 39A. The auxiliary secondary transmission driven intermediate gear is a reverse-inclined helical gear that has the same pitch circle diameter and the same number of teeth as the auxiliary transmission driven intermediate gear 39A.

[0097] The auxiliary secondary transmission driven gear is fixed to the second output shaft 40B coaxially with the auxiliary transmission driven gear 39' and is supported rotatably about the axis O4. The auxiliary secondary transmission driven gear is a reverse-inclined helical gear with the same pitch diameter and number of teeth as the auxiliary transmission driven gear 39'. The auxiliary secondary transmission driven gear meshes with the auxiliary secondary transmission driven intermediate gear.

[0098] Therefore, with this configuration, other forms of drive wheel 140 can simplify the basic configuration like drive wheel 110, while increasing the transmission capacity from the first output shaft 40A and the second output shaft 40B to the main shaft 50, and can reduce the thrust load while improving gear meshing using helical gears.

[0099] In addition, in this drive wheel 140 , the wheel 15 is fixed to the main shaft 50 .

[0100] With this drive wheel 140, the wheel 15 is rotated by the main shaft 50 to which rotational force is transmitted by the first conversion gear mechanism 14A, thereby simplifying the basic configuration, improving gear meshing, and reducing the thrust load of the transmission mechanism 13.

[0101] In addition, in this drive wheel 140, the rotation axis O5 of the wheel 15, which intersects the axis O2 of the main shaft 50 and runs vertically, is positioned offset horizontally from the axis O1 of the turning shaft 35, perpendicular to the axis O2 of the main shaft 50.

[0102] With this drive wheel 140, when the wheel 15 is not driven, the wheel 15 can passively turn by an external force acting from the horizontal direction. In other words, the cart 100 can be automatically driven and steered, and can also be manually driven and steered by an operator.

[0103] Moreover, the bogie 100 of the embodiment includes the above-described drive wheels 140 and the bogie body 101 to which the drive wheels 140 are attached. Therefore, the basic structure of the bogie 100 can be simplified, and the load can be reduced while improving the meshing of the gears.

[0104] [Embodiment 5 of Drive Wheel] Fig. 23 is a perspective view showing the basic configuration of a drive wheel of embodiment 5. Fig. 24 is a front view showing the basic configuration of a drive wheel of embodiment 5. Fig. 25 is a right side view showing the basic configuration of a drive wheel of embodiment 5.

[0105] Drive wheel 150 of the fifth embodiment differs from drive wheels 110, 120, 130, and 140 described above mainly in that it includes a rotational force transmission mechanism 16. In the following description of drive wheel 150 of the fifth embodiment, parts equivalent to those of drive wheels 110, 120, 130, and 140 described above are designated by the same reference numerals, and description thereof will be omitted.

[0106] As shown in FIGS. 23 to 25, the rotational force transmission mechanism 16 transmits the rotational force of the main shaft 50 to the axle 37 to which the wheel 15 is fixed.

[0107] The wheel 15 is integrally provided with an axle 37 that extends in the width direction Y along an axis O2 that is perpendicular to the direction in which the axis O1 extends (the up-down direction Z). One end of the axle 37 along the axis O2 is rotatably supported by a first support member 36A via a bearing (not shown), and the other end of the axle 37 along the axis O2 is rotatably supported by a second support member 36B via a bearing (not shown). The first support member 36A and the second support member 36B are provided below the pivot shaft 35 so as to extend downward on both sides of the wheel 15 in the width direction Y.

[0108] The main shaft 50 is supported by a pair of support portions 35b. The pair of support portions 35b extend downward in the up-down direction Z from the lower portion of the revolving shaft 35 and are arranged facing each other in the width direction Y. The main shaft 50 is supported by the pair of support portions 35b so as to be rotatable about an axis O8 that is parallel to the axis O2 of the axle 37.

[0109] The main shaft 50 supports the first support member 36A and the second support member 36B so as to be rotatable about an axis O8. The first support member 36A and the second support member 36B are connected by the main shaft 50 and the axle 37. Therefore, the first support member 36A and the second support member 36B are connected by the main shaft 50 and the axle 37 and are provided so as to be swingable together in the front-to-rear direction X around the axis O8 of the main shaft 50.

[0110] The first support member 36A and the second support member 36B are connected to the pivot shaft 35 via a pair of dampers 55. Each damper 55 is configured as a compression coil spring and has elasticity between one end and the other end, with one end supported by the pivot shaft 35 and the other end supported by the first support member 36A and the second support member 36B. Therefore, the first support member 36A and the second support member 36B are provided so as to be swingable within a predetermined range in the front-rear direction X about the axis O8 due to the length and elasticity between the one end and the other end of the damper 55. Therefore, the wheel 15 supported by the first support member 36A and the second support member 36B via the axle 37 is provided so as to be swingable within a predetermined range in the front-rear direction X about the axis O8. In addition, the wheels 15 supported by the first support member 36A and the second support member 36B are arranged so that the rotation axis O5 of the wheels 15, which is along the vertical direction intersecting the axis O2 of the axle 37, is shifted (offset) in the left-right direction in Figure 25 relative to the axis O1 of the turning shaft 35, and in the horizontal direction perpendicular to the axis O2 of the axle 37.

[0111] The rotational force transmission mechanism 16 is configured as a belt transmission mechanism including two pulleys 56 and a timing belt 57 wound around each of the pulleys 56. One of the pulleys 56 is fixed to the axle 37. The other pulley 56 is fixed to the main shaft 50. Therefore, the rotational force transmission mechanism 16 transmits the rotational force around the axis O8 of the main shaft 50 via the two pulleys 56 and the timing belt 57 as a rotational force around the axis O2 of the axle 37, thereby transmitting driving force to the wheels 15 via the axle 37.

[0112] This drive wheel 150 includes an axle 37 to which the wheel 15 is fixed, and a rotational force transmission mechanism 16 that transmits the rotational force of the main shaft 50 to the axle 37, and the rotational force transmission mechanism 16 positions the rotational axis O5 of the wheel 15, which intersects the axis O2 of the axle 37 and runs vertically, offset horizontally from the axis O1 of the turning shaft 35 and perpendicular to the axis O2 of the axle 37.

[0113] With this drive wheel 150, when the wheel 15 is not driven, the wheel 15 can passively turn by an external force acting from the horizontal direction. In other words, the cart 100 can be automatically driven and steered, and can also be manually driven and steered by an operator.

[0114] In the driving wheel 150 of the embodiment, the rotational force transmission mechanism 16 is formed of a belt transmission mechanism.

[0115] With this drive wheel 150, by using a belt transmission mechanism as the rotational force transmission mechanism 16, it is possible to easily implement a configuration in which the rotational axis O5 of the wheel 15, which intersects the axis O2 of the axle 37 and runs vertically, is shifted horizontally in a direction perpendicular to the axis O2 of the axle 37 relative to the axis O1 of the turning shaft 35.

[0116] Moreover, the bogie 100 of the embodiment includes the above-described drive wheels 150 and the bogie body 101 to which the drive wheels 150 are attached. Therefore, the basic structure of the bogie 100 can be simplified.

[0117] [Modifications] In the above-described drive wheels 110, 120, 130, 140, and 150, the power conversion mechanism 14 has been described as a bevel gear, but this is not limited thereto. For example, although not explicitly shown in the drawings, the power conversion mechanism 14 may be a helical gear, a worm gear, a crown gear, a universal joint, or the like.

[0118] DESCRIPTION OF SYMBOLS 13A First transmission gear mechanism (first transmission mechanism) 13B Second transmission gear mechanism (second transmission mechanism) 13C Third transmission gear mechanism (third transmission mechanism) 13D Fourth transmission gear mechanism (fourth transmission mechanism) 14A First conversion gear mechanism (first power conversion mechanism) 14B Second conversion gear mechanism (second power conversion mechanism) 15 Wheel 16 Rotational force transmission mechanism 35 Swivel shaft 38A First transmission drive gear 38B Second transmission drive gear 39 Main transmission driven gear 39' Auxiliary transmission driven gear 39A Auxiliary transmission driven intermediate gear 39B Main transmission driven intermediate gear 40A First output shaft 40B Second output shaft 50 Main shaft 100 Bogie 101 Bogie body 110, 120, 130, 140, 150 Drive wheel

Claims

1. A drive wheel comprising: a first input shaft and a second input shaft arranged on the same axis; a first output shaft arranged on an axis separate from the first input shaft and the second input shaft; a first transmission mechanism including a first transmission drive gear and a main transmission driven gear so as to transmit a rotational force of the first input shaft to the first output shaft; a second transmission mechanism including a second transmission drive gear having the same number of teeth as the first transmission drive gear so as to transmit the rotational force of the second input shaft to the first output shaft, a main transmission driven intermediate gear that meshes with the second transmission drive gear to reverse the direction of rotation, and the main transmission driven gear; a rotatable main shaft to which a wheel is connected; a first power conversion mechanism that transmits the rotational force of the first output shaft to the main shaft; and a turning shaft that supports the wheel so as to be rotatable via the main shaft.

2. The drive wheel of claim 1, wherein said wheel is fixed to said main shaft.

3. The drive wheel according to claim 1, wherein each of said transmission mechanisms is constituted by a helical gear.

4. The drive wheel according to claim 3, wherein the second transmission mechanism includes an auxiliary main transmission driven intermediate gear consisting of a reverse-inclined helical gear that is coaxially arranged with the main transmission driven intermediate gear, has the same pitch diameter, the same number of teeth, and is arranged with the same angle as the main transmission driven intermediate gear, and an auxiliary main transmission driven gear consisting of a reverse-inclined helical gear that is coaxially arranged with the main transmission driven gear, has the same pitch diameter, the same number of teeth, and is arranged with the same angle as the main transmission driven gear.

5. A drive wheel as described in claim 1, further comprising: a second output shaft on a different axis from the first output shaft; a third transmission mechanism including the first transmission drive gear, an auxiliary transmission driven intermediate gear that meshes with the first transmission drive gear to reverse the direction of rotation, and an auxiliary transmission driven gear so as to transmit the rotational force of the first input shaft to the second output shaft; a fourth transmission mechanism including the second transmission drive gear and the auxiliary transmission driven gear so as to transmit the rotational force of the second input shaft to the second output shaft; and a second power conversion mechanism that transmits the rotational force of the second output shaft to the main shaft.

6. The drive wheel according to claim 5, wherein each of said transmission mechanisms is constituted by a helical gear.

7. A driving wheel as set forth in claim 6, wherein the second transmission mechanism includes an auxiliary main transmission driven intermediate gear consisting of a reverse-inclined helical gear coaxially arranged with the same pitch circle diameter and number of teeth as the main transmission driven intermediate gear, and an auxiliary main transmission driven gear consisting of a reverse-inclined helical gear coaxially arranged with the same pitch circle diameter and number of teeth as the main transmission driven intermediate gear, and the third transmission mechanism includes an auxiliary secondary transmission driven intermediate gear consisting of a reverse-inclined helical gear coaxially arranged with the same pitch circle diameter and number of teeth as the secondary transmission driven intermediate gear, and an auxiliary secondary transmission driven gear consisting of a reverse-inclined helical gear coaxially arranged with the same pitch circle diameter and number of teeth as the main transmission driven gear.

8. A drive wheel as claimed in any one of claims 1 to 7, wherein the axis of rotation of the wheel, which runs vertically and intersects with the axis of the main shaft, is shifted horizontally relative to the axis of the pivot shaft, perpendicular to the axis of the main shaft.

9. A drive wheel as described in claim 1, comprising: an axle to which the wheel is fixed; and a rotational force transmission mechanism which transmits the rotational force of the main shaft to the axle, wherein the rotational force transmission mechanism displaces the rotational axis of the wheel, which runs vertically and intersects with the axis of the axle, in a horizontal direction perpendicular to the axis of the axle relative to the axis of the pivot shaft.

10. The drive wheel according to claim 9, wherein the rotational force transmission mechanism is a belt transmission mechanism.

11. A bogie comprising: a drive wheel; and a bogie body to which the drive wheel is attached, wherein the drive wheel comprises: a first input shaft and a second input shaft arranged on the same axis; a first output shaft arranged on a separate axis from the first input shaft and the second input shaft; a first transmission mechanism including a first transmission drive gear and a main transmission driven gear so as to transmit the rotational force of the first input shaft to the first output shaft; a second transmission mechanism including a second transmission drive gear having the same number of teeth as the first transmission drive gear so as to transmit the rotational force of the second input shaft to the first output shaft, a main transmission driven intermediate gear that meshes with the second transmission drive gear to reverse the direction of rotation, and the main transmission driven gear; a rotatable main shaft to which wheels are connected; a first power conversion mechanism that transmits the rotational force of the first output shaft to the main shaft; and a rotating shaft that supports the wheels rotatably via the main shaft.

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