Conveying device and drive wheel

Abstract

To realize stable traveling.SOLUTION: A conveying device comprises: a carriage base 102; at least two drive wheels 110 each having a drive wheel swing shaft 35 that supports a drive wheel 15 in a manner of being able to swing; at least one follower wheel 210 having a follower wheel swing shaft 235 that supports a follower wheel 215 in a manner of being able to swing; a drive wheel side suspension mechanism 106 that is positioned above the carriage base 102 and connects the carriage base 102 and each drive wheel 110 via a drive wheel side elastic member 54; and a follower wheel side suspension mechanism 206 that is positioned above the carriage base 102 and connects the carriage base 102 and each follower wheel 210 via a follower wheel side elastic member 254. A modulus of elasticity E1 of the drive wheel side elastic member 54 and a modulus of elasticity E2 of the follower wheel side elastic member 254 satisfy the relationship E2<E1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] BACKGROUND ART For example, Patent Document 1 discloses a conventional conveyance device having a vehicle body, a plurality of drive wheels supported by the vehicle body, and a plurality of driven wheels supported by the vehicle body.

[0003] Furthermore, for example, Patent Document 2 discloses a suspension mechanism for omnidirectional wheels and a self-propelled transport vehicle using the same mechanism. In Patent Document 2, the suspension mechanism is provided with a parallel link.

[0004] Furthermore, for example, Patent Document 3 discloses a suspension device for a vehicle, which includes a bilaterally actuated suspension for attenuating vertical forces generated by the relative, opposing vertical movements of a tire structure and a vehicle body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-106685 [Patent Document 2] Japanese Patent Application Publication No. 2019-209896 [Patent Document 3] Special Publication No. 2013-538318 Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, mecanum wheels or omni wheels are assumed as drive wheels. Such wheels usually use four wheels as a set, and if three or more wheels are not in contact with the ground, there is a risk of slipping on the floor surface. In addition, such wheels also cause vibration. Therefore, when using such wheels, stable running may be difficult.

[0007] On the other hand, for drive wheels used in self-propelled transport trolleys, while having a suspension mechanism, it is desired to ensure turning performance and achieve a low floor height. To ensure turning performance, it is necessary to prevent the attitude of the turning axis from tilting by the suspension mechanism. To achieve a low floor height, it is necessary to prevent the suspension mechanism from expanding the mutual distance between the drive wheel side and the vehicle body side.

[0008] The present disclosure has been made in view of the above problems, and an object thereof is to provide a transport device capable of realizing stable running. Another object of the present disclosure is to provide a drive wheel that has a suspension mechanism, can ensure turning performance, and can achieve a low floor height.

Means for Solving the Problems

[0009] A transport device according to an aspect of the present disclosure for achieving the above object includes a trolley base, at least two drive wheels having a drive wheel turning axis for rotatably supporting the drive wheels, at least one driven wheel having a driven wheel turning axis for rotatably supporting the driven wheels, a drive wheel side suspension mechanism located above the trolley base and connecting the trolley base and each of the drive wheels via a drive wheel side elastic member, and a driven wheel side suspension mechanism located above the trolley base and connecting the trolley base and each of the driven wheels via a driven wheel side elastic member, wherein the elastic modulus E1 of the drive wheel side elastic member and the elastic modulus E2 of the driven wheel side elastic member satisfy the relationship E2 < E1.

[0010] As a desirable aspect of the above transport device, the elastic modulus E1 of the drive wheel side elastic member and the elastic modulus E2 of the driven wheel side elastic member satisfy the relationship E1 = 1 / 3 × E2.

[0011] In a preferred embodiment of the above-mentioned transport device, the drive wheels are arranged at symmetrical positions with respect to the center of the carriage base.

[0012] In a desirable aspect of the above-mentioned conveying device, the drive wheel side elastic member includes a first drive wheel side elastic member that is compressed when the bogie base and the drive wheel move away from each other, and a second drive wheel side elastic member that is compressed when the bogie base and the drive wheel move toward each other, and the driven wheel side elastic member includes a first driven wheel side elastic member that is compressed when the bogie base and the driven wheel move away from each other, and a second driven wheel side elastic member that is compressed when the bogie base and the driven wheel move toward each other.

[0013] In a preferred embodiment of the above-mentioned conveying device, the drive wheel side suspension mechanism has a plurality of drive wheel side suspension shafts that are arranged parallel to the axis of the drive wheel swivel shaft of the drive wheel and connect the bogie base and each of the drive wheels so as to be able to move relative to each other, and the driven wheel side suspension mechanism has a plurality of driven wheel side suspension shafts that are arranged parallel to the axis of the driven wheel swivel shaft of the driven wheel and connect the bogie base and each of the driven wheels so as to be able to move relative to each other.

[0014] In a preferred embodiment of the above-mentioned conveying device, the drive wheel side suspension mechanism includes a drive wheel side connecting member that interconnects the plurality of drive wheel side suspension shafts of each of the drive wheels, and the driven wheel side suspension mechanism includes a driven wheel side connecting member that interconnects the plurality of drive wheel side suspension shafts of each of the driven wheels.

[0015] As a desirable aspect of the above-mentioned conveying device, the drive wheel side suspension mechanism further includes a drive wheel side regulating mechanism that regulates the amount of movement of the drive wheel side connecting member and the drive wheel toward each other, and the driven wheel side suspension mechanism further includes a driven wheel side regulating mechanism that regulates the amount of movement of the driven wheel side connecting member and the driven wheel toward each other.

[0016] As a desirable aspect of the above-described conveying device, in a state where the driving wheel side elastic member does not generate an elastic force, a first distance L1 on the driving wheel side from the ground contact point of the driving wheel to the carriage base, and a second distance L2 on the driving wheel side from the ground contact point of the driving wheel to the driving wheel base that supports the driving wheel satisfy the relationship L1 < L2. A regulated distance L3 on the driving wheel side regulated by the driving wheel side regulating mechanism and a distance L4 on the driving wheel side between the carriage base and the driving wheel base satisfy the relationship L3 < L4. In the driven wheel side suspension mechanism, in a state where the driven wheel side elastic member does not generate an elastic force, a first distance L1' on the driven wheel side from the ground contact point of the driven wheel to the carriage base, and a second distance L2' on the driven wheel side from the ground contact point of the driven wheel to the driven wheel base that supports the driven wheel satisfy the relationship L1' < L2'. A regulated distance L3' on the driven wheel side regulated by the driven wheel side regulating mechanism and a distance L4' on the driven wheel side between the carriage base and the driven wheel base satisfy the relationship L3' < L4'.

[0017] As a desirable aspect of the above-described conveying device, each of the driving wheel side suspension shafts causes a first movement on the driving wheel side where the carriage base and the driving wheel base move away from each other and a second movement on the driving wheel side where the carriage base and the driving wheel base approach each other in a state where the driving wheel side elastic member does not generate an elastic force. Each of the driven wheel side suspension shafts causes a first movement on the driven wheel side where the carriage base and the driven wheel base move away from each other and a second movement on the driven wheel side where the carriage base and the driven wheel base approach each other in a state where the driven wheel side elastic member does not generate an elastic force.

[0018] As a desirable aspect of the above-described conveying device, it includes a lifting mechanism provided on the carriage base that moves in the vertical direction with respect to the carriage base and fits into the conveyed object.

[0019] To achieve the above object, a drive wheel according to one aspect of the present disclosure includes a bogie base, a wheel base located above the bogie base and on which a drive wheel body is disposed, and a suspension mechanism that connects the bogie base and the wheel base via an elastic member. The drive wheel body has a pivot shaft that supports the wheel pivotably with respect to the wheel base. The suspension mechanism has a plurality of suspension shafts disposed parallel to the axis of the pivot shaft and connecting the bogie base and the wheel base so as to be relatively movable.

[0020] In a desirable aspect of the above drive wheel, a head is provided at one end of the suspension shaft, the bogie base is fixed to the other end of the suspension shaft, a sliding support member is provided slidably in the axial direction of the suspension shaft between both ends of the suspension shaft, the sliding support member is fixed to the wheel base, a first elastic member is disposed between the head and the wheel base, and a second elastic member is disposed between the wheel base and the bogie base.

[0021] In a desirable aspect of the above drive wheel, the elastic member includes a first elastic member that is compressed by the movement of the bogie base and the wheel base away from each other, and a second elastic member that is compressed by the movement of the bogie base and the wheel base approaching each other.

[0022] In a desirable aspect of the above drive wheel, it further includes a connecting member that connects each of the suspension shafts to each other.

[0023] In a desirable aspect of the above drive wheel, it further includes a restricting mechanism that restricts the amount of movement of the connecting member and the drive wheel body approaching each other.

[0024] In a desirable aspect of the above drive wheel, in an initial state where the elastic member does not generate an elastic force, a first distance L1 from the ground contact point of the wheel to the bogie base and a second distance L2 from the ground contact point of the wheel to the wheel base satisfy the relationship L1 < L2, and a restricting distance L3 restricted by the restricting mechanism and a distance L4 between the bogie base and the wheel base satisfy the relationship L3 < L4.

[0025] As a desirable aspect of the above-mentioned drive wheels, in an initial state in which the elastic member does not generate elastic force, each of the suspension axes causes a first movement in which the bogie base and the wheel base move away from each other, and a second movement in which the bogie base and the wheel base move closer to each other. [Effects of the Invention]

[0026] According to the present disclosure, stable driving can be achieved. Furthermore, according to the present disclosure, cornering performance can be ensured and a low floor can be achieved while providing a suspension mechanism. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a conveying device according to an embodiment, as viewed from above. [Figure 2] FIG. 2 is a perspective view of the conveying device of the embodiment as viewed from below. [Figure 3] FIG. 3 is a bottom view of the transport device according to the embodiment. [Figure 4] FIG. 4 is a bottom view of another example of the transport device according to the embodiment. [Figure 5] FIG. 5 is a bottom view of another example of the transport device according to the embodiment. [Figure 6] FIG. 6 is a bottom view of another example of the transport device according to the embodiment. [Figure 7] FIG. 7 is a perspective view of a drive wheel according to the embodiment. [Figure 8] FIG. 8 is a side view of a drive wheel according to the embodiment. [Figure 9] FIG. 9 is a perspective view showing a driving wheel body of the driving wheel of the embodiment. [Figure 10] FIG. 10 is a perspective view showing a drive system of a drive wheel body of a drive wheel according to the embodiment. [Figure 11] FIG. 11 is an exploded perspective view of a drive wheel according to an embodiment. [Figure 12] FIG. 12 is a schematic diagram showing a driving force transmission path of a driving wheel body of a driving wheel according to the embodiment. [Figure 13] FIG. 13 is a side view showing the operation of the drive wheels of the embodiment. [Figure 14] FIG. 14 is a side view showing the operation of the drive wheels of the embodiment. [Figure 15] FIG. 15 is a perspective view of a driven wheel according to the embodiment. [Figure 16] FIG. 16 is a side view of the driven wheel of the embodiment. [Figure 17] FIG. 17 is a front view of the driven wheel of the embodiment. [Figure 18] FIG. 18 is a perspective view showing a conveying device and a conveyed object to which the driving wheels of the embodiment are applied. [Figure 19] FIG. 19 is a schematic diagram showing another example of a driving force transmission path of the driving wheel main body of the driving wheel of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] 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.

[0029] The conveying device 1 of the embodiment is applied as a device that travels on a floor surface while carrying an object 600 to be conveyed as shown in Fig. 18. The conveying device 1 is used as a conveying auxiliary device such as an automatic guided vehicle (AGV), an autonomous mobile robot (AMR), or an auxiliary driving device for conveying. The object 600 to be conveyed may be, for example, a hand lifter, a forklift, a picking robot, or medical equipment (for example, a stretcher shown in Fig. 18).

[0030] As shown in FIGS. 1 to 3, the conveyance device 1 includes a carriage body 100, a driving wheel 110, a driven wheel 210, and a lifting mechanism 310.

[0031] The carriage body 100 is a base on which the drive wheels 110, the driven wheels 210, and the lifting mechanism 310 are arranged, and also serves as a case that houses the drive wheels 110, the driven wheels 210, and the lifting mechanism 310.

[0032] The carriage body 100 has a carriage base 102 and a case 101 surrounding the upper part of the carriage base 102. The carriage base 102 constitutes the base of the conveyance device 1 and is formed in a plate shape, constituting, for example, the bottom plate of the conveyance device 1. The carriage base 102 has drive wheels 110, driven wheels 210, and an elevating mechanism 310 arranged on its plate-shaped upper surface. The case 101 is composed of a wall 101A rising upward from the plate-shaped periphery of the carriage base 102, and a top plate (not shown) facing the plate-shaped carriage base 102 and covering the upper part of the wall 101A. Therefore, the drive wheels 110, driven wheels 210, and elevating mechanism 310 arranged on the carriage base 102 are housed inside the carriage body 100 consisting of the carriage base 102 and the case 101.

[0033] As shown in Figures 1 to 6, at least two drive wheels 110 are provided on the carriage body 100, as will be described in detail later. As shown in Figures 1 to 6, at least one driven wheel 210 is provided on the carriage body 100, as will be described in detail later.

[0034] The drive wheels 110 are arranged at symmetrical positions with respect to the center O (or any central position) of the bogie base 102 of the bogie main body 100. In Fig. 3, the drive wheels 110 are arranged at the front and rear in the traveling direction indicated by the arrow R, with the center O of the bogie base 102 as the reference. In this case, two driven wheels 210 are provided, and are arranged on the left and right of the traveling direction indicated by the arrow R, with the center O of the bogie base 102 as the reference.

[0035] 4, the drive wheels 110 are arranged diagonally in front of and behind the traveling direction indicated by the arrow R, with the center O of the carriage base 102 as the reference point. In this case, two driven wheels 210 are provided, and are arranged diagonally opposite to the drive wheels 110, with the center O of the carriage base 102 as the reference point, with the drive wheels 110 arranged diagonally in front of and behind the traveling direction indicated by the arrow R.

[0036] 5, the drive wheels 110 are arranged on the left and right sides of the traveling direction indicated by the arrow R, with the center O of the carriage base 102 as the reference. In this case, two driven wheels 210 are provided, and are arranged in front and behind the center O of the carriage base 102 as the reference, with the traveling direction indicated by the arrow R.

[0037] 6, the drive wheels 110 are arranged on the left and right sides of the center O of the carriage base 102 as a reference point, on the rear or front side in the direction of travel indicated by the arrow R. In this case, one driven wheel 210 is provided, and is arranged on the front or rear side in the direction of travel indicated by the arrow R, on the center O of the carriage base 102 as a reference point.

[0038] As shown in FIG. 1 , the lifting mechanism 310 is disposed in the center, including the center O, of the plate-shaped upper surface of the bogie base 102 of the bogie main body 100, so as to be surrounded by the drive wheels 110 and the driven wheels 210. The lifting mechanism 310 includes a link mechanism 311, a connection module 312, and a drive unit 313. The link mechanism 311 is formed, for example, by a pantograph or an X-link, and is provided between the bogie base 102 and the connection module 312. The connection module 312 is fitted to the car body 500 shown in FIG. 18 . The drive unit 313 is formed, for example, by an actuator, and drives the link mechanism 311. The lifting mechanism 310 drives the link mechanism 311 using the drive unit 313, thereby moving the connection module 312 in the up and down direction via the link mechanism 311. The connection module 312, which moves downward, is housed in the bogie main body 100. The connection module 312 moving upward fits into the car body 500 and connects the carriage body 100 to the car body 500. The conveyance device 1, in which the carriage body 100 is connected to the car body 500, conveys the conveyed object (stretcher) 600 together with the car body 500 by traveling.

[0039] As shown in FIG. 18, the transport device 1 of the embodiment includes a vehicle body 500 and a stretcher 600.

[0040] As shown in Fig. 18, the vehicle body 500 has a frame body 510 and casters 520. The frame body 510 surrounds the periphery of the transport device 1. The frame body 510 has a pair of left and right first frames 511 extending in the front-rear direction of the traveling direction R, and a pair of front and rear second frames 512 extending in the left-right direction so as to connect the first frames 511. The first frames 511 are arranged parallel to the left and right, and the second frames 512 are arranged parallel to the front and rear, and these form the frame body 510 in a frame shape.

[0041] A total of four casters 520 are provided. The casters 520 are provided at the front and rear ends of each first frame 511. The casters 520 are provided to be rotatable around an axis extending in the vertical direction, and to be revolvable around an axis extending in the horizontal direction.

[0042] The stretcher 600 has a lifting arm 610 and a bed section 620. The lifting arm 610 is attached to the frame body 510 of the vehicle body 500 and extends in the vertical direction. The lifting arm 610 is configured with a link mechanism and is deformable so as to expand and contract in the vertical direction. The lifting arms 610 are provided at four locations on the front, back, left and right of the frame body 510. The bed section 620 is the part on which a patient or the like rests and is provided mainly horizontally. The bed section 620 is attached to the lifting arm 610 and is provided so as to be able to be raised and lowered in the vertical direction by the lifting arm 610.

[0043] The following describes the details of the drive wheel 110. As shown in Figures 7 to 9, the drive wheel 110 includes a carriage base 102, a drive wheel base (wheel base) 103, a drive wheel main body 105, and a drive wheel side suspension mechanism (suspension mechanism) 106.

[0044] The carriage base 102 constitutes the base of the above-described transport device 1. The carriage base 102 is formed in a plate shape and constitutes, for example, the bottom plate of the transport device 1.

[0045] The drive wheel base 103 forms the base of the drive wheel 110. The drive wheel base 103 is formed in a plate shape. The drive wheel bases 103 are arranged above the bogie base 102, with their plate surfaces facing each other up and down. By arranging the drive wheel base 103, which forms the base of the drive wheel 110, above the bogie base 102, the overall height of the drive wheel 110 can be lowered compared to when the drive wheel base 103 is arranged below the bogie base 102, allowing for a lower floor.

[0046] The drive wheel main body 105 is disposed on the drive wheel base 103, and has the drive mechanism 11 shown in FIG. 9, the swivel unit 12 shown in FIG. 8, the transmission mechanism 13 shown in FIG. 10, the power conversion mechanism 14, and the drive wheel (wheel) 15. The drive mechanism 11 inputs a rotational force to the drive wheel main body 105. The swivel unit 12 is disposed on the drive wheel base 103. 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 drive wheel 15. The drive wheel 15 is rotatable by the rotational force input from the drive mechanism 11 via the transmission mechanism 13 and the power conversion mechanism 14, and is steerable by the swivel unit 12.

[0047] The drive mechanism 11 includes a first drive mechanism 22A and a second drive mechanism 22B.

[0048] The first 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 with a motor. The first drive unit 23A is fixed to the drive wheel base 103. The first drive unit 23A has a drive shaft 23Aa that protrudes above the upper surface of the drive wheel base 103 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 upper end of the first input shaft 25A. The first driven pulley 26A and the first drive 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 a ring shape and is wound around the first driven pulley 26A and the first drive pulley 24A. Therefore, in the first drive mechanism 22A, the first drive pulley 24A is rotated by the driving of the first drive unit 23A, and this rotation is transmitted from the first drive pulley 24A to the first driven pulley 26A via the first drive belt 27A, thereby rotating the first input shaft 25A.

[0049] The second 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 drive wheel base 103. The second drive unit 23B has a drive shaft 23Ba that protrudes above the upper surface of the drive wheel base 103 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 rotatably 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 arranged to be rotatable relative to the first input shaft 25A so as to rotate independently of the first input shaft 25A. The second driven pulley 26B is fixed to the upper end of the second input shaft 25B. 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 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 drive belt 27B is formed in an annular shape and is wound around the second driven pulley 26B and the second driving pulley 24B. Therefore, when the second drive mechanism 22B drives the second driving unit 23B, 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 drive belt 27B, thereby rotating the second input shaft 25B.

[0050] As shown in FIG. 8, the swivel unit 12 is made up of a drive wheel swivel shaft (swivel shaft) 35 and a support member 36.

[0051] The drive wheel pivot shaft 35 is formed in a disk shape, and its center is an axis O1. The drive wheel pivot shaft 35 is rotatably supported by a through-hole formed in the protrusion 103A of the drive wheel base 103 by vertically penetrating the protrusion 103A. As a result, the drive wheel pivot shaft 35 is supported rotatably about the axis O1 relative to the drive wheel base 103. The drive wheel pivot shaft 35 also rotatably supports the first input shaft 25A of the first drive mechanism 22A. Therefore, the first input shaft 25A is supported rotatably about the axis O1 relative to the drive wheel pivot shaft 35, and is also supported rotatably about the axis O1 relative to the drive wheel base 103. In other words, the drive wheel pivot shaft 35 is rotatable with respect to the drive wheel base 103 regardless of the rotation of the first input shaft 25A. The drive wheel pivot shaft 35 also rotatably supports the second input shaft 25B of the second drive mechanism 22B. Therefore, the second input shaft 25B is supported via the first input shaft 25A to be rotatable relative to the drive wheel turning shaft 35 about the axis O1, and is also supported to be rotatable relative to the drive wheel base 103 about the axis O1. In other words, the drive wheel turning shaft 35 is rotatable relative to the drive wheel base 103 regardless of the rotation of the second input shaft 25B. In this way, the first input shaft 25A, the second input shaft 25B, and the drive wheel turning shaft 35 are rotatably arranged coaxially along the axis O1.

[0052] The support members 36 are provided below the drive wheel pivot shaft 35 and are arranged on both sides of the drive wheel 15 in the horizontal direction. The drive wheel 15 is integrally provided with an axle 37 (see FIG. 10) extending along an axis O2 perpendicular to the direction in which the axis O1 extends (up and down direction). Each end of the axle 37 along the axis O2 is rotatably supported by the support members 36. Also, as shown in FIG. 8, the rotation axis O5 of the drive wheel 15 along the vertical direction intersecting the axis O2 of the axle 37 is arranged to be shifted (offset) from the axis O1 of the drive wheel pivot shaft 35 in the horizontal direction perpendicular to the axis O2 of the axle 37.

[0053] As shown in Fig. 10, the transmission mechanism 13 has a first transmission mechanism 13A and a second transmission mechanism 13B. The first transmission mechanism 13A is configured to include a first transmission drive gear 38A, a first transmission driven gear 39A, and a first output shaft 40A. The second transmission mechanism 13B is configured to include a second transmission drive gear 38B, a second transmission driven gear 39B, and a second output shaft 40B. In this embodiment, the first transmission drive gear 38A, the first transmission driven gear 39A, the second transmission drive gear 38B, and the second transmission driven gear 39B are configured as helical gears.

[0054] In the first transmission mechanism 13A, the first transmission drive gear 38A, the first transmission driven gear 39A, and the first output shaft 40A are disposed on the support member 36 of the swivel unit 12. The first transmission drive gear 38A is fixed to the lower end of the first input shaft 25A, which passes through the second input shaft 25B. The first transmission driven gear 39A meshes with the first transmission drive gear 38A. The first transmission driven gear 39A is fixed to the first output shaft 40A. The first output shaft 40A is supported on the support member 36 so as to be rotatable about an axis O3. When viewed in the axial direction of the axle 37, i.e., in a side view (see FIG. 8) in which the axis O2 of the axle 37 is viewed at a point, the axis O3 of the first output shaft 40A is inclined relative to the axis O1 of the first input shaft 25A. The axial directions of the first output shaft 40A and the axle 37 are different by 90 degrees. In addition, the axis O3 of the first output shaft 40A intersects with the axis O2 in a side view (see FIG. 8).

[0055] In the second transmission mechanism 13B, the second transmission drive gear 38B, the second transmission driven gear 39B, and the second output shaft 40B are disposed on the support member 36 of the swivel unit 12. The second transmission drive gear 38B is fixed to the lower end of the second input shaft 25B. The second transmission driven gear 39B meshes with the second transmission drive gear 38B. The second transmission driven gear 39B is fixed to the second output shaft 40B. The second input shaft 25B is supported on the support member 36 so as to be rotatable about an axis O4. When viewed in the axial direction of the axle 37, i.e., in a side view (see FIG. 8) in which the axis O2 of the axle 37 is viewed at a point, the axis O4 of the second input shaft 25B is inclined with respect to the axis O1 of the second input shaft 25B. The axial directions of the second output shaft 40B and the axle 37 differ by 90 degrees. In addition, the axis O4 of the second output shaft 40B intersects with the axis O2 in a side view (see FIG. 8).

[0056] 10, the power conversion mechanism 14 has a first power conversion mechanism 14A and a second power conversion mechanism 14B. The first power conversion mechanism 14A is composed of a first conversion drive gear 41A and a first conversion driven gear 42A. The second power conversion mechanism 14B is composed of a second conversion drive gear 41B and a second conversion driven gear 42B. In this embodiment, the first conversion drive gear 41A, the first conversion driven gear 42A, the second conversion drive gear 41B, and the second conversion driven gear 42B are composed of bevel gears.

[0057] In the first power converting mechanism 14A, the first converted driving gear 41A is fixed to the lower end of the first output shaft 40A. The first converted driven gear 42A is fixed to one end of the axle 37. The first converted driving gear 41A meshes with the first converted driven gear 42A. Therefore, the first power converting mechanism 14A converts rotation around the axis O3 of the first output shaft 40A into rotation around the axis O2 of the axle 37.

[0058] In the second power converting mechanism 14B, the second conversion driving gear 41B is fixed to the lower end of the second output shaft 40B. The second conversion driven gear 42B is fixed to the other end of the axle 37. The second conversion driving gear 41B meshes with the second conversion driven gear 42B. Therefore, the second power converting mechanism 14B converts rotation about the axis O4 of the second output shaft 40B into rotation about the axis O2 of the axle 37.

[0059] The drive wheel main body 105 can rotate and steer the drive 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 rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B the same, the drive wheels 15 can be rotated without being steered. In this case, by making the rotational speeds (rotational speeds) of the first input shaft 25A and the second input shaft 25B different, the drive wheels 15 can be steered while rotating or stopped.

[0060] Here, the operation of the drive wheel main body 105 will be described. As shown in FIG. 12, when the first input shaft 25A of the drive wheel main body 105 is rotated in the A1 direction, the first transmission drive gear 38A rotates in the same direction, the first transmission driven gear 39A rotates in the A2 direction together with the first output shaft 40A, and the first conversion drive gear 41A rotates in the same direction. Then, the first conversion driven gear 42A rotates in the A3 direction, causing the axle 37 to rotate in the same direction. On the other hand, when the second input shaft 25B of the drive wheel main body 105 is rotated in the B1 direction, which is the opposite direction to the A1 direction, the second transmission drive gear 38B rotates in the same direction, the second transmission driven gear 39B rotates in the B2 direction together with the second output shaft 40B, and the second conversion drive gear 41B rotates in the same direction. Then, the second conversion driven gear 42B rotates in the B3 direction, causing the axle 37 to rotate in the same direction. Here, since the A3 direction and the B3 direction are the same rotation direction, if the first input shaft 25A and the second input shaft 25B have the same rotation speed, the drive wheels 15 rotate without turning.

[0061] At this time, when the drive wheel main body 105 reduces the rotation speed of the second input shaft 25B relative to the rotation speed of the first input shaft 25A, the rotation speed input from the second conversion drive gear 41B to the axle 37 via the second conversion driven gear 42B becomes lower than the rotation speed input from the first conversion drive gear 41A to the axle 37 via the first conversion driven gear 42A. Then, the drive wheel turning shaft 35 rotates by the rotation speed difference, turning and steering the drive wheels 15. Furthermore, when the drive wheel main body 105 stops rotating the rotation speed of the second input shaft 25B, the rotation speed input from the second conversion drive gear 41B to the axle 37 via the second conversion driven gear 42B becomes zero, and the drive wheels 15 turn and steer without rotating.

[0062] As shown in FIG. 9 , the drive wheel main body 105 has a swivel position detector 107. The swivel position detector 107 is provided on a protrusion 103A of the drive wheel base 103. For example, the drive wheel main body 105 has a first spur gear that rotates around an axis O1 together with the drive wheel pivot shaft 35, a second spur gear that rotates around an axis parallel to the axis O1, a belt 107A wound around the first and second spur gears, and a detector that detects the rotational position of the second spur gear. Therefore, the drive wheel main body 105 can detect the rotational position of the drive wheel pivot shaft 35, i.e., the rotational position of the pivot unit 12 relative to the drive wheel base 103, by having the first spur gear rotate together with the drive wheel pivot shaft 35 and detecting the rotational position of the first spur gear as the rotational position of the second spur gear with the detector.

[0063] The drive wheel body 105 has a differential omnidirectional movement mechanism. That is, in the drive wheel body 105, 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 then transmitted from the first output shaft 40A and the second output shaft 40B to each end of the axle 37 via the first power conversion mechanism 14A and the second power conversion mechanism 14B. The drive wheel body 105 can switch between the rotation and steering of the drive wheels 15 by adjusting the rotation speed of the first input shaft 25A and the second input shaft 25B. Therefore, the conveyance device 1 equipped with the drive wheels 110 is capable of omnidirectional movement.

[0064] Furthermore, the drive wheel body 105 is arranged so that the rotation axis O5 of the drive wheel 15, which is along the vertical direction intersecting the axis O2 of the axle 37, is offset in the horizontal direction perpendicular to the axis O2 of the axle 37 with respect to the axis O1 of the drive wheel turning shaft 35. Therefore, when the drive wheel body 105 does not drive the drive wheel 15, the drive wheel 15 can passively turn due to an external force acting from the horizontal direction. In other words, the drive wheel body 105 can automatically travel and steer, and can also be manually traveled and steered by an operator.

[0065] As shown in Figure 11, the drive wheel side suspension mechanism 106 has a sliding support member 51, a drive wheel side suspension shaft (suspension shaft) 52, a spacer member 53, a drive wheel side elastic member (elastic member) 54, and a drive wheel side connecting member (connecting member) 55.

[0066] The sliding support member 51 is fixed to the drive wheel base 103. The sliding support member 51 has a cylindrical body 51A with a through hole and a flange 51B that is integrally provided on the outer periphery of the cylindrical body 51A. The cylindrical body 51A is inserted into the through hole 103B (see FIG. 9) of the drive wheel base 103. The flange 51B is fixed to the drive wheel base 103 with screws.

[0067] The drive-wheel-side suspension shaft 52 is formed in a rod shape and is inserted into a through-hole in the cylindrical body 51A of the sliding support member 51. By inserting the drive-wheel-side suspension shaft 52 into the through-hole in the cylindrical body 51A, the drive-wheel-side suspension shaft 52 is supported so as to be able to slide along an axis O6 extending in the vertical direction. The axis O6 is parallel to the axis O1, which is the center of rotation of the drive-wheel main body 105 relative to the drive-wheel base 103. The drive-wheel-side suspension shaft 52 is provided with a flange-shaped head 52A at one end in the sliding direction. The head 52A has an engagement portion that engages with a tool. In the drive wheel 110 of this embodiment, the engagement portion of the head 52A is configured as a hexagonal socket. The drive-wheel-side suspension shaft 52 is provided with a male screw portion 52B at the other end in the sliding direction. The male screw portion 52B of the drive-wheel-side suspension shaft 52 is screwed into the bogie base 102. Therefore, the drive wheel side suspension shaft 52 has the bogie base 102 fixed to the other end in the sliding direction.

[0068] The spacer member 53 is configured as a cylindrical member that is inserted into and tightly fitted onto the suspension shaft 52. The spacer member 53 is provided between the cylindrical body 51A of the sliding support member 51 and a second elastic member 54B (described later) interposed therebetween, and functions to define the lower limit of the movement range of the wheel base 103. The spacer member 53 is configured as a cylindrical member that is inserted into and tightly fitted onto the suspension shaft 52. The spacer member 53 is provided between the cylindrical body 51A of the sliding support member 51 and a second elastic member 54B (described later) interposed therebetween, and functions to define the lower limit of the movement range of the wheel base 103. The spacer member 53 may be configured as a nut member that is screwed onto the male thread portion 52B of the suspension shaft 52. In this case, the spacer member 53 can prevent the component (the second elastic member 54B (described later)) inserted into the suspension shaft 52 from falling off during assembly, etc.

[0069] The driving wheel side elastic member 54 includes a first driving wheel side elastic member (first elastic member) 54A and a second driving wheel side elastic member (second elastic member) 54B. The first driving wheel side elastic member 54A is configured as a compression coil spring, and is inserted through the driving wheel side suspension shaft 52 and wound around the driving wheel side suspension shaft 52. As shown in FIG. 8, the first driving wheel side elastic member 54A is disposed between the head 52A of the driving wheel side suspension shaft 52 and the flange 51B of the sliding support member 51 fixed to the wheel base 103. The second driving wheel side elastic member 54B is configured as a compression coil spring, and is inserted through the driving wheel side suspension shaft 52 and wound around the driving wheel side suspension shaft 52. As shown in FIG. 8, the second driving wheel side elastic member 54B is disposed between the spacer member 53 (the bogie base 102) and the cylindrical body 51A of the sliding support member 51. The second drive wheel side elastic member 54B does not necessarily have to be provided.

[0070] The drive-wheel-side connecting member 55 connects multiple drive-wheel-side suspension shafts 52. In the drive wheel 110 of this embodiment, four drive-wheel-side suspension mechanisms 106 are provided, each including a slide support member 51, a drive-wheel-side suspension shaft 52, a spacer member 53, and a drive-wheel-side elastic member 54. The drive wheel 110 is provided with at least two sets of drive-wheel-side suspension mechanisms 106. The drive-wheel-side connecting member 55 is formed by bending a metal plate and includes a support plate 55A and a connecting plate 55B. The support plate 55A is provided corresponding to each set of the drive-wheel-side suspension mechanism 106 and has a through-hole 55Aa through which the drive-wheel-side suspension shaft 52 is inserted. The head portion 52A of the drive-wheel-side suspension shaft 52 does not pass through the through-hole 55Aa. Therefore, the support plate 55A is disposed between the head 52A and the first drive-wheel-side elastic member 54A with the drive-wheel-side suspension shaft 52 inserted therethrough. The connecting plate 55B has a plurality of raised portions 55Ba and a base plate 55Bb connecting the raised portions 55Ba. The connecting plate 55B is bent downward into a U-shape above the drive-wheel main body 105 to cover the drive mechanism 11. The connecting plate 55B is integrally formed by bending the support plate 55A to the lower end of the raised portions 55Ba. Therefore, the connecting plate 55B is integrally formed with the support plates 55A. Therefore, the drive-wheel-side connecting member 55 connects the drive-wheel-side suspension shafts 52 inserted through the support plates 55A. The drive-wheel-side connecting member 55 is disposed such that the support plate 55A faces the protrusion 103A of the drive-wheel base 103 in the up-down direction.

[0071] As shown in FIG. 8, in the drive wheel side suspension mechanism 106 configured as described above, the drive wheel side suspension shaft 52 is disposed along an axis O6 (axial direction) extending vertically parallel to the turning axis O1. The center of the drive wheel side suspension shaft 52 is inserted into a slide support member 51 fixed to the drive wheel base 103, and the lower end is fixed to the bogie base 102. A plurality of drive wheel side suspension shafts 52 are provided on the drive wheel base 103 and the bogie base 102. The drive wheel side suspension shafts 52 are desirably disposed at symmetrical positions with the axis O1, which is the turning center of the drive wheel main body 105 provided on the drive wheel base 103, interposed therebetween. In the drive wheel 110 of this embodiment, the drive wheel side suspension shafts 52 are provided at a total of four locations, symmetrical positions with the axis O1, which is the turning center of the drive wheel main body 105 provided on the drive wheel base 103, interposed therebetween. The bogie base 102 is formed with a through-hole 102A (see FIGS. 2 to 6 and 11) through which the drive wheel 15 of the drive wheel main body 105 passes. Therefore, the drive wheel side suspension mechanism 106 is provided so that the drive wheel base 103 and the bogie base 102 can move relatively in the up and down direction as shown by arrow A in FIG. 8 via the drive wheel side suspension shaft 52. The drive wheel side suspension mechanism 106 also has a first drive wheel side elastic member 54A provided between the head 52A of the drive wheel side suspension shaft 52 (support plate 55A of the drive wheel side coupling member 55) and the drive wheel base 103 (flange 51B of the sliding support member 51). The first drive wheel side elastic member 54A is compressed when the drive wheel base 103 and the bogie base 102 move away from each other. Therefore, the drive wheel side suspension mechanism 106 applies an elastic force when the drive wheel base 103 and the bogie base 102 move away from each other. Furthermore, the drive wheel side suspension mechanism 106 has a second drive wheel side elastic member 54B provided between the drive wheel base 103 (the cylindrical body 51A of the sliding support member 51) and the bogie base 102 (the spacer member 53). The second drive wheel side elastic member 54B is compressed when the drive wheel base 103 and the bogie base 102 move toward each other. Therefore, the drive wheel side suspension mechanism 106 applies an elastic force when the drive wheel base 103 and the bogie base 102 move toward each other.In this way, the drive wheel side suspension mechanism 106 connects the drive wheel base 103 and the carriage base 102 via the drive wheel side elastic member 54 so as to be capable of relative movement.

[0072] The operation of the drive wheel 110 of the embodiment will be described below. The drive wheel 110 is normally used in a state where the drive wheel 15 is in contact with a flat floor surface G on which the vehicle runs, and the first drive wheel side elastic member 54A is pre-loaded under the weight of the bogie base 102 (vehicle).

[0073] As shown in FIG. 13 , when a convex portion G1 is present on a flat floor surface G, the drive wheel 15 of the drive wheel 110 rides up on the convex portion G1. When the drive wheel 15 rides up on the convex portion G1, the drive wheel main body 105 rises as shown by arrow A1, and the drive wheel base 103 moves away from the carriage base 102, whose position remains unchanged. Then, the drive wheel side suspension mechanism 106 applies an elastic force to the drive wheel base 103 and the carriage base 102, preventing the drive wheel base 103 from moving away from each other due to compression of the first drive wheel side elastic member 54A. Therefore, the drive wheel 110 is urged downward by the elastic force of the drive wheel main body 105 together with the drive wheel base 103, and the drive wheel 15 is pressed against the convex portion G1. As a result, the drive wheel 110 can pass over the convex portion G1 while generating a driving force from the drive wheel main body 105.

[0074] Here, the support plate 55A of the drive wheel side connecting member 55 and the protrusion 103A of the drive wheel base 103 constitute a drive wheel side restricting mechanism 108 that restricts the amount of movement of the drive wheel side connecting member 55 and the drive wheel main body 105 toward each other. In the drive wheel 110 of this embodiment, when the drive wheel 15 rides up on the protrusion G1, the drive wheel base 103 moves away from the bogie base 102, and the protrusion 103A and the support plate 55A move relatively closer to each other. As described above, the drive wheel side connecting member 55 is configured so that the connecting plate 55B is above the drive wheel main body 105 and covers the drive mechanism 11. Therefore, when the drive wheel 15 rides up on the protrusion G1, the connecting plate 55B and the drive mechanism 11 move relatively closer to each other and may come into contact with each other. As described above, in the drive wheel side restricting mechanism 108, the support plate 55A of the drive wheel side connecting member 55 is disposed to face the protrusion 103A of the drive wheel base 103 in the vertical direction, and the mutual contact prevents the connecting plate 55B from contacting the drive mechanism 11. One way to prevent the connecting plate 55B from contacting the drive mechanism 11 is to design the connecting plate 55B and the drive mechanism 11 so that they are spaced apart from each other in advance. However, this would increase the overall height of the drive wheel 110, hindering a low-floor design. In this regard, the drive wheel 110 of the embodiment can ensure the function of the drive mechanism 11 (drive wheel main body 105) while achieving a low floor design by preventing the connecting plate 55B from contacting the drive mechanism 11 using the drive wheel side restricting mechanism 108. In addition, by regulating the distance between the support plate 55A of the connecting member 55 and the protrusion 103A of the wheel base 103, the regulating mechanism 108 can prevent the elastic member 54 (first elastic member 54A) of the suspension mechanism 106 from being excessively compressed, causing plastic deformation and making it impossible to compress, thereby preventing a loss of suspension function.

[0075] As shown in FIG. 14 , when a recess G2 is present on a flat floor G, the drive wheel 15 of the drive wheel 110 falls into the recess G2. When the drive wheel 15 falls into the recess G2, the drive wheel main body 105 descends as indicated by arrow A2, and the drive wheel base 103 approaches the bogie base 102. Then, the drive wheel side suspension mechanism 106 applies an elastic force to the drive wheel base 103 and the bogie base 102 as they move closer to each other by compressing the second drive wheel side elastic member 54B. Therefore, the drive wheel 110 prevents the first drive wheel side elastic member 54A from reaching its natural length at which it does not generate an elastic force, as the drive wheel base 103 is urged upward by the elastic force of the second drive wheel side elastic member 54B. Therefore, the first drive wheel side elastic member 54A provides an elastic force that presses the drive wheel main body 105 downward, and the drive wheel 15 is pressed against the recess G2. As a result, the drive wheel 110 can pass through the recess G2 while generating a driving force from the drive wheel body 105.

[0076] The following describes in detail the driven wheel 210. The driven wheel 210 includes a driven wheel base 203, a driven wheel body 205, and a driven wheel side suspension mechanism 206, as shown in Figures 15 to 17.

[0077] The driven wheel base 203 constitutes the base of the driven wheel 210. The driven wheel base 203 is formed in a plate shape. The driven wheel bases 203 are arranged above the bogie base 102, with their plate surfaces facing each other up and down. By arranging the driven wheel base 203, which forms the base of the driven wheel 210, above the bogie base 102, the overall height of the driven wheel 210 can be lowered compared to when the driven wheel base 203 is arranged below the bogie base 102, and a lower floor can be achieved.

[0078] The driven wheel body 205 is disposed on the driven wheel base 203, and has a swivel unit 212 and a driven wheel 215 shown in FIG. 15. The swivel unit 212 is disposed on the driven wheel base 203. The driven wheel 215 is provided on the swivel unit 212 and is rotatable, and can be steered by the swivel unit 212.

[0079] As shown in FIG. 8, the swivel unit 212 is made up of a driven wheel swivel shaft 235 and a support member 236.

[0080] The driven wheel turning shaft 235 has its center as an axis O21 and is rotatably supported while vertically penetrating the driven wheel base 203. As a result, the driven wheel turning shaft 235 is supported so as to be rotatable relatively to the driven wheel base 203 about the axis O21.

[0081] The support members 236 are provided below the driven wheel turning shaft 235 and are arranged on both sides of the driven wheel 215 in the horizontal direction. The driven wheel 215 is integrally provided with an axle 237 extending along an axis O22 perpendicular to the direction in which the axis O21 extends (up and down direction). Each end of the axle 237 along the axis O22 is supported rotatably by the support members 236. Also, as shown in FIG. 16 , the rotation axis O25 of the driven wheel 215 along the vertical direction intersecting the axis O22 of the axle 237 is arranged to be shifted (offset) from the axis O21 of the driven wheel turning shaft 235 in the horizontal direction perpendicular to the axis O22 of the axle 237.

[0082] The driven wheel body 205 is disposed such that the rotation axis O25 of the driven wheel 215, which is along the vertical direction intersecting the axis O22 of the axle 237, is shifted in the horizontal direction perpendicular to the axis O22 of the axle 237 with respect to the axis O21 of the driven wheel turning shaft 235. Therefore, the driven wheel body 205 can passively turn by an external force acting on the driven wheel 215 from the horizontal direction. In other words, the driven wheel body 205 is steered passively.

[0083] The driven wheel side suspension mechanism 206 has the same configuration as the above-mentioned drive wheel side suspension mechanism 106. As shown in Figures 15 to 17, the driven wheel side suspension mechanism 206 has a slide support member 251, a driven wheel side suspension shaft 252, a driven wheel side elastic member 254, and a driven wheel side connecting member 255, which have configurations corresponding to the slide support member 51, drive wheel side suspension shaft 52, drive wheel side elastic member 54, and drive wheel side connecting member 55 of the drive wheel side suspension mechanism 106.

[0084] The sliding support member 251 is fixed to a fixed base 203C of the driven wheel base 203. The fixed base 203C is a portion formed by bending an end of the driven wheel base 203 into a crank shape, and is arranged above the bogie base 102, just like the driven wheel base 203, with the plate surfaces of the fixed base 203C facing each other up and down. The fixed base 203C is located closer to the bogie base 102 than the driven wheel base 203. The sliding support member 251 has a cylindrical body 251A with a through hole, and a flange 251B provided integrally with the outer periphery of the cylindrical body 251A. The cylindrical body 251A is inserted into the through hole 203B of the driven wheel base 203. The flange 251B is fixed to the driven wheel base 203 with screws.

[0085] The driven wheel side suspension shaft 252 is formed in a rod shape and is inserted into a through-hole in the cylindrical body 251A of the sliding support member 251. By inserting the driven wheel side suspension shaft 252 into the through-hole in the cylindrical body 251A, the driven wheel side suspension shaft 252 is supported so as to be able to slide along an axis O26 extending in the vertical direction. The axis O26 is parallel to the axis O21, which is the center of rotation of the driven wheel main body 205 relative to the driven wheel base 203. A male thread portion 252B is provided at the lower end portion in the sliding direction of the driven wheel side suspension shaft 252. The male thread portion 252B of the driven wheel side suspension shaft 252 is screwed into the bogie base 102. Therefore, the bogie base 102 is fixed to the lower end portion in the sliding direction of the driven wheel side suspension shaft 252.

[0086] The driven wheel side connecting member 255 connects multiple driven wheel side suspension shafts 252. In the driven wheel 210 of this embodiment, four sets of driven wheel side suspension mechanisms 206 are provided, each set including a slide support member 251, a driven wheel side suspension shaft 252, and a driven wheel side elastic member 254. The driven wheel 210 is provided with at least two sets of driven wheel side suspension mechanisms 206. The driven wheel side connecting member 255 is formed of metal or the like, and connects at least two sets of driven wheel side suspension mechanisms 206. The driven wheel side connecting member 255 fixes the upper ends of the driven wheel side suspension shafts 252 of each connected set of driven wheel side suspension mechanisms 206. The driven wheel side connecting member 255 is arranged to face the fixed base 203C of the driven wheel base 203 in the up-down direction.

[0087] The driven wheel side elastic member 254 has a first driven wheel side elastic member 254A and a second driven wheel side elastic member 254B. The first driven wheel side elastic member 254A is configured as a compression coil spring, and is inserted through the driven wheel side suspension shaft 252 and wound around the driven wheel side suspension shaft 252. The first driven wheel side elastic member 254A is disposed between a driven wheel side connecting member 255 that fixes the upper end of the driven wheel side suspension shaft 252 and a flange 251B of the sliding support member 251. The second driven wheel side elastic member 254B is configured as a compression coil spring, and is inserted through the driven wheel side suspension shaft 252 and wound around the driven wheel side suspension shaft 252. The second driven wheel side elastic member 254B is disposed between the cylindrical body 251A of the sliding support member 251 and the bogie base 102. The second driven wheel side elastic member 254B does not necessarily have to be provided.

[0088] 8, in the driven wheel side suspension mechanism 206 configured in this manner, the driven wheel side suspension shaft 252 is arranged along an axis O26 that extends in the vertical direction parallel to the turning axis O21. The driven wheel side suspension shaft 252 is inserted into a slide support member 251 whose center is fixed to the driven wheel base 203, and its lower end is fixed to the bogie base 102. A plurality of driven wheel side suspension shafts 252 are provided on the driven wheel base 203 and the bogie base 102. It is desirable to arrange the driven wheel side suspension shafts 252 at symmetrical positions with the axis O21, which is the turning center of the driven wheel main body 205 provided on the driven wheel base 203, between them. In the driven wheel 210 of this embodiment, the driven wheel side suspension shafts 252 are provided at a total of four locations at symmetrical positions with respect to the axis O21, which is the rotation center of the driven wheel main body 205 provided on the driven wheel base 203. The bogie base 102 is formed with a through hole 102A (see FIGS. 2 to 6) through which the driven wheel 215 of the driven wheel main body 205 passes. Therefore, the driven wheel side suspension mechanism 206 is provided so that the driven wheel base 203 and the bogie base 102 can move relatively in the up and down direction via the driven wheel side suspension shaft 252, as shown by arrow A in FIGS. 16 and 17. Furthermore, the driven wheel side suspension mechanism 206 has a first driven wheel side elastic member 254A provided between a driven wheel side connecting member 255 that fixes the upper end of the driven wheel side suspension shaft 252 and the driven wheel base 203 (fixed base 203C). The first driven wheel side elastic member 254A is compressed by the relative movement of the driven wheel base 203 and the bogie base 102 away from each other. Therefore, the driven wheel side suspension mechanism 206 applies an elastic force against the relative movement of the driven wheel base 203 and the bogie base 102 away from each other. Furthermore, the driven wheel side suspension mechanism 206 is provided with a second driven wheel side elastic member 254B between the driven wheel base 203 (the cylindrical body 251A of the sliding support member 251) and the bogie base 102. The second driven wheel side elastic member 254B is compressed by the relative movement of the driven wheel base 203 and the bogie base 102 toward each other. Therefore, the driven wheel side suspension mechanism 206 applies an elastic force against the relative movement of the driven wheel base 203 and the bogie base 102 toward each other. In this way, the driven wheel side suspension mechanism 206 connects the driven wheel base 203 and the carriage base 102 via the driven wheel side elastic member 254 so as to be capable of relative movement.

[0089] The following describes the operation of the driven wheel 210. The driven wheel 210 is normally used in a state where the driven wheel 215 is in contact with a flat floor surface G on which the vehicle runs, and the first driven wheel side elastic member 254A and the second driven wheel side elastic member 254B are preloaded under the weight of the bogie base 102 (vehicle).

[0090] Similar to the drive wheel 110 (see FIG. 13), when a convex portion G1 is present on a flat floor surface G, the driven wheel 215 of the driven wheel 210 rides up on the convex portion G1. When the driven wheel 215 rides up on the convex portion G1, the driven wheel body 205 rises, and the driven wheel base 203 moves away from the carriage base 102, whose position remains unchanged. Then, the driven wheel side suspension mechanism 206 applies an elastic force to the driven wheel base 203 and the carriage base 102, which move away from each other, by compressing the first driven wheel side elastic member 254A. Therefore, the driven wheel 210 is urged downward by the elastic force of the driven wheel body 205 together with the driven wheel base 203, and the driven wheel 215 is pressed against the convex portion G1. As a result, the driven wheel 210 can pass over the convex portion G1 while generating a driving force from the driven wheel body 205.

[0091] Here, a regulating member 255A that faces the fixed base 203C of the driven wheel base 203 at the top and bottom is fixed to the lower part of the driven wheel side coupling member 255. Then, as shown in Fig. 17, the regulating member 255A of the driven wheel side coupling member 255 and the fixed base 203C of the driven wheel base 203 constitute a driven wheel side regulating mechanism 208 that regulates the amount of movement of the driven wheel side coupling member 255 and the fixed base 203C toward each other. In the driven wheel 210 of the embodiment, when the driven wheel 215 rides up on the convex portion G1, the driven wheel base 203 moves away from the bogie base 102, and the fixed base 203C and the regulating member 255A move relatively closer to each other. The driven wheel side regulating mechanism 208 can prevent the driven wheel base 203 and the driven wheel 215 from rising excessively by bringing the regulating member 255A and the fixed base 203C into contact with each other.

[0092] Also, similar to the drive wheel 110 (see FIG. 14), when there is a recess G2 on the flat floor surface G, the driven wheel 210 causes the driven wheel 215 to fall into this recess G2. When the driven wheel 215 falls into the recess G2, the driven wheel body 205 descends, and the driven wheel base 203 approaches the carriage base 102. Then, the driven wheel side suspension mechanism 206 applies an elastic force to the relative movement in which the driven wheel base 203 and the carriage base 102 approach each other due to the compression of the second driven wheel side elastic member 254B. For this reason, the driven wheel 210 avoids the first driven wheel side elastic member 254A from becoming the natural length without generating an elastic force because the driven wheel base 203 is biased upward by the elastic force of the second driven wheel side elastic member 254B, and an elastic force for pushing the driven wheel body 205 downward by the first driven wheel side elastic member 254A is ensured, and the driven wheel 215 is pressed against the recess G2. As a result, the driven wheel 210 can pass through the recess G2 while generating a driving force by the driven wheel body 205.

[0093] In the conveying device 1 of the above-described embodiment, there are a carriage base 102, at least two drive wheels 110 having a drive wheel pivot shaft 35 that rotatably supports the drive wheels 15, at least one driven wheel 210 having a driven wheel pivot shaft 235 that rotatably supports the driven wheels 215, a drive wheel side suspension mechanism 106 that is located above the carriage base 102 and connects the carriage base 102 and the individual drive wheels 110 via drive wheel side elastic members 54 (54A, 54B), and a driven wheel side suspension mechanism 206 that is located above the carriage base 102 and connects the carriage base 102 and the individual driven wheels 210 via driven wheel side elastic members 254 (254A, 254B), and the elastic modulus E1 of the drive wheel side elastic member 54 and the elastic modulus E2 of the driven wheel side elastic member 254 satisfy the relationship E2 < E1.

[0094] According to this conveying device 1, by including at least two drive wheels 110 capable of turning the drive wheels 15 and at least one driven wheel 210 capable of turning the driven wheels 215, the grounding property of each drive wheel 110 is improved as compared with a mecanum wheel or an omnidirectional wheel. Moreover, according to this conveying device 1, a drive wheel side suspension mechanism 106 that is located above the carriage base 102 and connects the drive wheel 110 to the carriage base 102, and a driven wheel side suspension mechanism 206 that is located above the carriage base 102 and connects the driven wheel 210 to the carriage base 102 are included, so that a lower floor can be achieved as compared with a configuration in which the drive wheel 110 and the driven wheel 210 are connected to the carriage base 102 via a suspension mechanism on its upper side. Moreover, according to this conveying device 1, the elastic modulus E1 of the drive wheel side elastic member 54 and the elastic modulus E2 of the driven wheel side elastic member 254 are in a relationship of E2 < E1, so that the pressing force of the drive wheel 110 against the floor surface G increases, and the grounding property of the drive wheel 110 on the floor surface G is improved. As a result, the conveying device 1 of the embodiment can achieve stable traveling while achieving a lower floor.

[0095] In the conveying device 1 of the embodiment, the elastic modulus E1 of the drive wheel side elastic member 54 and the elastic modulus E2 of the driven wheel side elastic member 254 satisfy the relationship of E1 = 1 / 3 × E2.

[0096] According to this conveying device 1, due to the relationship of E1 = 1 / 3 × E2, the pressing force of the drive wheel 110 against the floor surface G can be appropriately increased, and the grounding property of the drive wheel 110 on the floor surface G is further improved. As a result, the conveying device 1 of the embodiment can more easily achieve stable traveling.

[0097] In the conveying device 1 of the embodiment, the drive wheels 110 are arranged at symmetric positions with respect to the center O of the carriage base 102.

[0098] According to this conveying device 1, due to the position of the drive wheels 110 with respect to the center O of the carriage base 102, the grounding property of each drive wheel 110 is improved. As a result, the conveying device 1 of the embodiment can more easily achieve stable traveling.

[0099] In addition, in the embodiment of the conveying device 1, the drive wheel side elastic member 54 includes a first drive wheel side elastic member 54A that is compressed when the carriage base 102 and the drive wheel 110 move away from each other, and a second drive wheel side elastic member 54B that is compressed when the carriage base 102 and the drive wheel 110 move toward each other, and the driven wheel side elastic member 254 includes a first driven wheel side elastic member 254A that is compressed when the carriage base 102 and the driven wheel 210 move away from each other, and a second driven wheel side elastic member 254B that is compressed when the carriage base 102 and the driven wheel 210 move toward each other.

[0100] According to this conveying device 1, the drive wheel side elastic member 54 can generate an elastic force when the carriage base 102 and the drive wheel 110 move toward or away from each other, and the driven wheel side elastic member 254 can generate an elastic force when the carriage base 102 and the driven wheel 210 move toward or away from each other. Therefore, according to this conveying device 1, the drive wheel 15 and the driven wheel 215 are pressed against the floor surface G, and even if there are convex portions G1 or concave portions G2 on the floor surface G, it is possible to run with the drive wheel 15 and the driven wheel 215 pressed against these. As a result, according to this conveying device 1, stable running can be achieved depending on the condition of the floor surface G.

[0101] In addition, in the embodiment of the conveying device 1, the driving wheel side suspension mechanism 106 has a plurality of driving wheel side suspension axes 52 arranged parallel to the axis O1 of the driving wheel swivel axis 35 of the driving wheel 110, and connects the carriage base 102 and each driving wheel 110 so as to be able to move relative to each other, and the driven wheel side suspension mechanism 206 has a plurality of driven wheel side suspension axes 252 arranged parallel to the axis O21 of the driven wheel swivel axis 235 of the driven wheel 210, and connects the carriage base 102 and each driving wheel 210 so as to be able to move relative to each other.

[0102] According to this transport device 1, the multiple drive-wheel-side suspension shafts 52 that connect the carriage base 102 and the drive wheels 110 so as to be able to move relative to each other are arranged parallel to the axis O1 of the drive-wheel pivot shaft 35 that turns the drive wheels 15, thereby preventing the axis O1 of the drive-wheel pivot shaft 35 from tilting when the drive-wheel-side suspension mechanism 106 is operating. Also, according to this transport device 1, the multiple driven-wheel-side suspension shafts 252 that connect the carriage base 102 and the driven wheels 210 so as to be able to move relative to each other are arranged parallel to the axis O21 of the driven-wheel pivot shaft 235 that turns the driven wheels 215, thereby preventing the axis O21 of the driven-wheel pivot shaft 235 from tilting when the driven-wheel-side suspension mechanism 206 is operating. If the drive-wheel pivot shaft 35 and the driven-wheel pivot shaft 235 are tilted with respect to the floor surface G, it becomes difficult for the drive wheels 110 and the driven wheels 210 to smoothly rotate. In this regard, the conveyance device 1 can smoothly perform the turning operation of the drive wheels 110 and the driven wheels 210. As a result, the conveyance device 1 can ensure turning performance and achieve stable running.

[0103] In addition, in the embodiment of the conveying device 1, the driving wheel side suspension mechanism 106 includes a driving wheel side connecting member 55 that interconnects multiple driving wheel side suspension shafts 52 of each driving wheel 110, and the driven wheel side suspension mechanism 206 includes a driven wheel side connecting member 255 that interconnects multiple driven wheel side suspension shafts 252 of each driven wheel 210.

[0104] This transport device 1 allows easy and reliable assembly of the drive-wheel-side suspension shafts 52 so that they are parallel to the axis O1 of the drive-wheel pivot shaft 35. Furthermore, this transport device 1 allows easy and reliable assembly of the driven-wheel-side suspension shafts 252 so that they are parallel to the axis O21 of the driven-wheel pivot shaft 235.

[0105] In the transport device 1 of the embodiment, the drive wheel side suspension mechanism 106 further includes a drive wheel side restriction mechanism 108 that restricts the amount of movement in which the drive wheel side connecting member 55 and the drive wheel 110 approach each other, and the driven wheel side suspension mechanism 206 further includes a driven wheel side restriction mechanism 208 that restricts the amount of movement in which the driven wheel side connecting member 255 and the driven wheel 210 approach each other.

[0106] According to this transport device 1, it is possible to prevent the drive wheel 110 and the driven wheel 210 from rising excessively.

[0107] In the transport device 1 of the embodiment, in a state where the drive wheel side elastic member 54 does not generate an elastic force, the drive wheel side first distance L1 from the ground contact point of the drive wheel 15 to the drive wheel side of the carriage base 102 and the drive wheel side second distance L2 from the ground contact point of the drive wheel 15 to the drive wheel base 103 that supports the drive wheel 110 satisfy the relationship L1 < L2, and the drive wheel side restriction distance L3 restricted by the drive wheel side restriction mechanism 108 and the drive wheel side distance L4 between the carriage base 102 and the drive wheel base 103 satisfy the relationship L3 < L4. Further, in the transport device 1 of the embodiment, in a state where the driven wheel side elastic member 254 does not generate an elastic force, the driven wheel side first distance L1' from the ground contact point of the driven wheel 215 to the driven wheel side of the carriage base 102 and the driven wheel side second distance L2' from the ground contact point of the driven wheel 215 to the driven wheel base 203 that supports the driven wheel 210 satisfy the relationship L1' < L2', and the driven wheel side restriction distance L3' restricted by the driven wheel side restriction mechanism 208 and the driven wheel side distance L4' between the carriage base 102 and the driven wheel base 203 satisfy the relationship L3' < L4'.

[0108] According to this conveying device 1, by satisfying the relationships of L1 < L2, L1' < L2', and L3 < L4, L3' < L4', even if there are convex portions G1 and concave portions G2 on the floor surface G, the driving wheels 15 of the driving wheels 110 and the driven wheels 215 of the driven wheels 210 can be pressed to achieve stable traveling. The elastic forces of the driving wheel side elastic member 54 and the driven wheel side elastic member 254 are ensured, and the contact between the driving wheel side connecting member 55 and the driving wheel 110 and the contact between the driven wheel side connecting member 255 and the driven wheel 210 are prevented while ensuring the elastic forces of the driving wheel side elastic member 54 and the driven wheel side elastic member 254. As a result, according to this conveying device 1, even if there are convex portions G1 and concave portions G2 on the floor surface G, the functions of the driving wheel side suspension mechanism 106 and the driven wheel side suspension mechanism 206 can be ensured.

[0109] Further, in the conveying device 1 of the embodiment, the driving wheel side suspension shaft 52 causes a first driving wheel side movement in which the carriage base 102 and the driving wheel base 103 move away from each other and a second driving wheel side movement in which the carriage base 102 and the driving wheel base 103 approach each other in a state where the driving wheel side elastic member 54 does not generate an elastic force. Furthermore, in the conveying device 1 of the embodiment, the driven wheel side suspension shaft 252 causes a first driven wheel side movement in which the carriage base 102 and the driven wheel base 203 move away from each other and a second driven wheel side movement in which the carriage base 102 and the driven wheel base 203 approach each other in a state where the driven wheel side elastic member 254 does not generate an elastic force.

[0110] According to this conveying device 1, the driving wheel side suspension shaft 52 can cause the first driving wheel side movement and the second driving wheel side movement, that is, an elastic force can be generated in the driving wheel side elastic member 54 in the first driving wheel side movement and the second driving wheel side movement. Furthermore, according to this conveying device 1, the driven wheel side suspension shaft 252 can cause the first driven wheel side movement and the second driven wheel side movement, that is, an elastic force can be generated in the driven wheel side elastic member 254 in the first driven wheel side movement and the second driven wheel side movement. As a result, according to this conveying device 1, even if there are convex portions G1 and concave portions G2 on the floor surface G, the functions of the driving wheel side suspension mechanism 106 and the driven wheel side suspension mechanism 206 can be ensured.

[0111] The transport device 1 of the embodiment also includes a lifting mechanism 310 that is provided on the carriage base 102 and moves up and down relative to the carriage base 102 to engage with the object to be transported.

[0112] According to this conveying device 1, when the conveying device does not fit the object to be conveyed, it is lowered by the lifting mechanism 310 that fits to the object to be conveyed, thereby enabling a low floor, and when the conveying device fits to the object to be conveyed, it is raised to fit and convey the object. By making the conveying device 1 low-floor, it can get under the object to be conveyed and fit to the object by the lifting mechanism 310.

[0113] The drive wheel 110 of the above-described embodiment includes a bogie base 102, a wheel base 103 located above the bogie base 102 and on which the drive wheel body 105 is disposed, and a suspension mechanism 106 that connects the bogie base 102 and the wheel base 103 via an elastic member 54, and the drive wheel body 105 has a swivel shaft 35 that supports the wheel 15 rotatably relative to the wheel base 103, and the suspension mechanism 106 is characterized by having a plurality of suspension shafts 52 that are arranged parallel to the axis O1 of the swivel shaft 35 and connect the bogie base 102 and the wheel base 103 so that they can move relative to each other.

[0114] According to this drive wheel 110, the multiple suspension shafts 52 that connect the bogie base 102 and the wheel base 103 so as to be able to move relative to each other are arranged parallel to the axis O1 of the swivel shaft 35 that rotates the wheel 15 relative to the wheel base 103, thereby preventing the axis O1 of the swivel shaft 35 from tilting when the suspension mechanism 106 is functioning. If the swivel shaft 35 tilts with respect to the floor G, it becomes difficult for the drive wheel main body 105 to perform a smooth turning operation. In this regard, according to this drive wheel 110, tilting of the axis O1 of the swivel shaft 35 is prevented, thereby enabling the drive wheel main body 105 to perform a smooth turning operation. As a result, this drive wheel 110 can ensure turning performance and achieve a low floor while being equipped with the suspension mechanism 106.

[0115] In addition, in the driving wheel 110 of the embodiment, a head 52A is provided at one end of the suspension axle 52, a bogie base 102 is fixed to the other end of the suspension axle 52, a sliding support member 51 is provided between both ends of the suspension axle 52 so as to be able to slide in the axial direction of the suspension axle 52, the sliding support member 51 is fixed to the wheel base 103, a first elastic member 54A is arranged between the head 52A and the wheel base 103, and a second elastic member 54A is arranged between the wheel base 103 and the bogie base 102.

[0116] According to this drive wheel 110, the bogie base 102 and the wheel base 103 are connected by the suspension shaft 52 so as to be able to move relative to each other. Furthermore, according to this drive wheel 110, by including the first elastic member 54A and the second elastic member 54B, the elastic member 54 can generate elastic force when the bogie base 102 and the wheel base 103 move toward and away from each other. Therefore, according to this drive wheel 110, the wheels 15 of the drive wheel main body 105 are pressed against the floor G, and even if the floor G has a convex portion G1 or a concave portion G2, it is possible to run with the wheels 15 pressed against these. As a result, according to this drive wheel 110, stable running can be achieved according to the condition of the floor G.

[0117] In addition, in the driving wheel 110 of the embodiment, the elastic member 54 is characterized by including a first elastic member 54A that is compressed when the bogie base 102 and the wheel base 103 move away from each other, and a second elastic member 54B that is compressed when the bogie base 102 and the wheel base 103 move toward each other.

[0118] According to this drive wheel 110, by including the first elastic member 54A and the second elastic member 54B, the elastic member 54 can generate elastic force when the carriage base 102 and the wheel base 103 move toward and away from each other. Therefore, with this drive wheel 110, the wheels 15 of the drive wheel main body 105 are pressed against the floor G, and even if there are protrusions G1 or recesses G2 on the floor G, it is possible to run with the wheels 15 pressed against these. As a result, with this drive wheel 110, stable running can be achieved depending on the conditions of the floor G.

[0119] Further, the drive wheel 110 of the embodiment is characterized by further including a connecting member 55 that connects the respective suspension shafts 52 to each other.

[0120] According to this drive wheel 110, by connecting the plurality of suspension shafts 52 to each other, it is possible to easily and surely perform an assembly in which the suspension shafts 52 are arranged in parallel with respect to the axis O1 of the turning shaft 35.

[0121] Further, the drive wheel 110 of the embodiment is characterized by further including a regulating mechanism 108 that regulates the amount of movement in which the connecting member 55 and the drive wheel body 105 approach each other.

[0122] According to this drive wheel 110, by regulating the amount of movement in which the connecting member 55 and the drive wheel body 105 approach each other, it is possible to prevent contact between the connecting member 55 and the drive wheel body 105.

[0123] Further, in the drive wheel 110 of the embodiment, as shown in FIG. 2, in an initial state where the elastic member 54 does not generate an elastic force, a first distance L1 from the ground contact point of the wheel 15 to the carriage base 102 and a second distance L2 from the ground contact point of the wheel 15 to the wheel base 103 satisfy the relationship L1 < L2, and a regulated distance L3 regulated by the regulating mechanism 108 and a distance L4 between the carriage base 102 and the wheel base 103 satisfy the relationship L3 < L4.

[0124] According to this drive wheel 110, by satisfying the relationships of L1 < L2 and L3 < L4, even if there are convex portions G1 and concave portions G2 on the floor G, the elastic force of the elastic member 54 is ensured so that the wheel 15 of the drive wheel body 105 can be pressed to achieve stable traveling, and the elastic force of the elastic member 54 can be ensured while preventing contact between the connecting member 55 and the drive wheel body 105. As a result, according to this drive wheel 110, even if there are convex portions G1 and concave portions G2 on the floor G, the function of the suspension mechanism 106 can be ensured.

[0125] Furthermore, in the driving wheel 110 of the embodiment, in the initial state in which the elastic member 54 does not generate elastic force, each suspension axis 52 is characterized in that it causes a first movement in which the bogie base 102 and the wheel base 103 move away from each other, and a second movement in which the bogie base 102 and the wheel base 103 move closer to each other.

[0126] With this drive wheel 110, each suspension shaft 52 can undergo first and second movements, i.e., elastic force can be generated in the elastic member 54 during the first and second movements. As a result, with this drive wheel 110, the function of the suspension mechanism 106 can be ensured even if the floor G has a convex portion G1 or a concave portion G2.

[0127] FIG. 19 is a schematic diagram showing another example of a driving force transmission path of the driving wheel main body of the driving wheel of the embodiment.

[0128] 19 differs from the drive wheel 120 in the configuration of the drive wheel body 105'. Therefore, in the following description of the drive wheel 120, parts equivalent to those of the drive wheel body 105 described above will be given the same reference numerals and will not be described again.

[0129] In the drive wheel main body 105', the drive mechanism 111 has a two-shaft integrated motor that inputs two rotational forces onto the axis O1 of the revolving shaft 35. The two-shaft integrated motor has a cylindrical support cylinder 121 fixed to the wheel base 103. The support cylinder 121 supports a first rotating cylinder 122A inside the support cylinder 121 so that it can rotate freely around the axis O1. The support cylinder 121 also supports a second rotating cylinder 122B outside the support cylinder 121 so that it can rotate freely around the axis O1. Although not shown in the figure, the support cylinder 121 is provided with coils (not shown) on both the inner and outer circumferential surfaces. The first rotating cylinder 122A has a magnet on its outer circumferential surface, and a first input shaft 25A extending along the axis O1 is provided at its lower part. The second rotating cylinder 122B has a magnet on its inner circumferential surface, and a second input shaft 25B extending along the axis O1 is provided at its lower part. Therefore, by energizing the coils of the support cylinder 121, a rotational force is input to the first input shaft 25A via the first rotary cylinder 122A, and a rotational force is input to the second input shaft 25B via the second rotary cylinder 122B. On the other hand, when no current is applied to the coils of the support cylinder 121, the first rotary cylinder 122A and the first input shaft 25A are rotatable relative to the support cylinder 121, and the second rotary cylinder 122B and the second input shaft 25B are rotatable.

[0130] In this drive wheel body 105', the first output shaft 40A and the second output shaft 40B are arranged parallel to the axis O1 of the turning shaft 35. In addition, in this drive wheel body 105', the rotation axis O5 of the wheel 15, which is along the vertical direction intersecting the axis O2 of the axle 37, is arranged on the axis O1 of the turning shaft 35.

[0131] In such a driving wheel 120, the same effects as those of the driving wheel 110 can be obtained by using the same configuration.

[0132] Although not shown in the drawings, the drive wheel body of the drive wheel of the embodiment can also be applied to wheel shapes of other types, such as a spherical wheel that rolls by itself. [Explanation of symbols]

[0133] 1. Conveyor device 15 Driving wheels (wheels) 35 Drive wheel pivot (pivot) 52 Drive wheel side suspension shaft (suspension shaft) 54 Drive wheel side elastic member (elastic member) 54A First driving wheel side elastic member (first elastic member) 54B second driving wheel side elastic member (second elastic member) 55 Drive wheel side connecting member (connecting member) 102 Bogie base 103 Drive wheel base (wheel base) 105(105') Drive wheel body 106 Drive wheel side suspension mechanism (suspension mechanism) 108 Drive wheel side regulation mechanism (regulation mechanism) 110 Drive Wheel 203 Driven Wheel Base 206 Driven wheel side suspension mechanism 208 Driven wheel side regulation mechanism 210 Driven Wheel 215 Driven wheels 235 Driven wheel pivot shaft 252 Driven wheel side suspension shaft 254 Driven wheel side elastic member 254A First driven wheel side elastic member 254B Second driven wheel side elastic member 255 Driven wheel side connecting member 310 Lifting mechanism

Claims

1. A bogie base and At least two drive wheels each having a drive wheel pivot shaft that rotatably supports the drive wheels; At least one driven wheel having a driven wheel pivot shaft that rotatably supports the driven wheel; a drive wheel side suspension mechanism located above the bogie base and connecting the bogie base and each of the drive wheels via a drive wheel side elastic member; a driven wheel side suspension mechanism located above the bogie base and connecting the bogie base and each of the driven wheels via a driven wheel side elastic member; Including, an elastic modulus E1 of the driving wheel side elastic member and an elastic modulus E2 of the driven wheel side elastic member satisfy the relationship E2<E1; Conveying device.

2. an elastic modulus E1 of the driving wheel side elastic member and an elastic modulus E2 of the driven wheel side elastic member satisfy the relationship E1 = 1 / 3 × E2; The conveying device according to claim 1 .

3. The drive wheels are arranged at symmetrical positions with respect to the center of the bogie base. The conveying device according to claim 1 .

4. the drive wheel side elastic member includes a first drive wheel side elastic member that is compressed when the bogie base and the drive wheel move away from each other, and a second drive wheel side elastic member that is compressed when the bogie base and the drive wheel move toward each other, The driven wheel side elastic member includes a first driven wheel side elastic member that is compressed when the bogie base and the driven wheel move away from each other, and a second driven wheel side elastic member that is compressed when the bogie base and the driven wheel move toward each other. The conveying device according to claim 1 .

5. the drive wheel side suspension mechanism has a plurality of drive wheel side suspension shafts that are arranged parallel to the axis of the drive wheel turning shaft of the drive wheel and connect the bogie base and each of the drive wheels so as to be movable relative to one another; the driven wheel side suspension mechanism has a plurality of driven wheel side suspension shafts that are arranged parallel to the axis of the driven wheel turning shaft of the driven wheel and connect the bogie base and each of the driven wheels so as to be relatively movable with respect to each other; The conveying device according to claim 1 .

6. the drive wheel side suspension mechanism includes a drive wheel side connecting member that connects the plurality of drive wheel side suspension shafts of each of the drive wheels to each other, the driven wheel side suspension mechanism includes a driven wheel side connecting member that connects the plurality of driven wheel side suspension shafts of each of the driven wheels to each other; The conveying device according to claim 5 .

7. the drive wheel side suspension mechanism further includes a drive wheel side restriction mechanism that restricts the amount of movement of the drive wheel side connecting member and the drive wheel toward each other, the driven wheel side suspension mechanism further includes a driven wheel side restriction mechanism that restricts the amount of movement of the driven wheel side connecting member and the driven wheel toward each other. The conveying device according to claim 6.

8. When the driving wheel side elastic member does not generate an elastic force, the driving wheel side suspension mechanism a first distance L1 on a drive wheel side from a ground contact point of the drive wheel to the bogie base and a second distance L2 on a drive wheel side from the ground contact point of the drive wheel to a drive wheel base supporting the drive wheel satisfy the relationship L1<L2, a drive wheel side restriction distance L3 restricted by the drive wheel side restriction mechanism and a drive wheel side distance L4 between the bogie base and the drive wheel base satisfy the relationship L3<L4, The driven wheel side suspension mechanism, in a state where the driven wheel side elastic member does not generate an elastic force, a first distance L1' from the ground contact point of the driven wheel to the bogie base on a driven wheel side and a second distance L2' from the ground contact point of the driven wheel to a driven wheel base supporting the driven wheel satisfy the relationship L1'<L2', a driven wheel side restriction distance L3' restricted by the driven wheel side restriction mechanism and a driven wheel side distance L4' between the bogie base and the driven wheel base satisfy the relationship L3'<L4'; 8. The conveying device according to claim 7.

9. each of the drive wheel side suspension shafts causes a first drive wheel side movement in which the bogie base and the drive wheel base move away from each other, and a second drive wheel side movement in which the bogie base and the drive wheel base move closer to each other, when the drive wheel side elastic member does not generate an elastic force; Each of the driven wheel side suspension shafts causes a first driven wheel side movement in which the bogie base and the driven wheel base move away from each other, and a second driven wheel side movement in which the bogie base and the driven wheel base move closer to each other, when the driven wheel side elastic member does not generate elastic force.

9. The conveying device according to claim 8.

10. a lifting mechanism provided on the carriage base and moving in a vertical direction relative to the carriage base to engage with the transported object; The conveying device according to claim 1 .

11. A bogie base and a wheel base located above the bogie base and on which a drive wheel main body is disposed; a suspension mechanism that connects the bogie base and the wheel base via an elastic member; Including, The drive wheel body has a pivot shaft that supports the wheel so that the wheel can pivot relative to the wheel base, the suspension mechanism has a plurality of suspension shafts arranged parallel to the axis of the pivot shaft and connecting the bogie base and the wheel base so as to be movable relative to each other; Drive wheel.

12. A head is provided at one end of the suspension shaft, The bogie base is fixed to the other end of the suspension shaft, a sliding support member is provided between both ends of the suspension shaft so as to be slidable in the axial direction of the suspension shaft; The sliding support member is fixed to the wheel base, A first elastic member is disposed between the head and the wheel base, A second elastic member is disposed between the wheel base and the bogie base. A drive wheel according to claim 11.

13. The elastic member includes a first elastic member that is compressed when the bogie base and the wheel base move away from each other, and a second elastic member that is compressed when the bogie base and the wheel base move toward each other. A drive wheel according to claim 11.

14. Further comprising a connecting member connecting each of the suspension shafts to each other. A drive wheel according to claim 11.

15. The drive wheel further includes a restricting mechanism that restricts the amount of movement of the connecting member and the drive wheel main body toward each other.

15. A drive wheel according to claim 14.

16. In an initial state in which the elastic member does not generate an elastic force, a first distance L1 from the ground contact point of the wheel to the bogie base and a second distance L2 from the ground contact point of the wheel to the wheel base satisfy a relationship of L1<L2; a regulating distance L3 regulated by the regulating mechanism and a distance L4 between the bogie base and the wheel base satisfy the relationship L3<L4; 16. A drive wheel according to claim 15.

17. In an initial state in which the elastic member does not generate an elastic force, each suspension axle provides a first movement of the bogie base and the wheel base away from each other and a second movement of the bogie base and the wheel base toward each other; 17. A drive wheel according to claim 16.

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