Drive unit and truck

Abstract

To provide technology that enables stable travel in a drive unit.SOLUTION: A drive unit 1 has a caster unit 3, omnidirectional drive wheels 2, and a support member 11. The support member supports the caster unit and the omnidirectional drive wheels. The caster unit has multiple wheels 31 facing each other through a gap, a caster shaft extending in the vertical direction and disposed between the wheels, and elastic members. The omnidirectional drive wheels 2 are drivable in any direction along a plane perpendicular to the vertical direction. The caster shaft is supported in the vertical direction by the elastic force provided by the elastic members.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] 2. Description of the Related Art Casters used in carts are known in the art (for example, Patent Document 1). [Patent Document 1] JP 2023-060468 A Summary of the Invention [Problem to be solved by the invention]

[0003] However, when a trolley is equipped with a single caster and omnidirectional drive wheels, there is a problem in that the trolley swings significantly from side to side when switching from forward to reverse motion.

[0004] An object of the present invention is to provide a technique for realizing stable driving in a drive unit. [Means for solving the problem]

[0005] The present invention is a drive unit having a caster section, an omnidirectional drive wheel, and a support member supporting the caster section and the omnidirectional drive wheel, wherein the caster section has a plurality of wheels facing each other with a gap therebetween, a caster shaft arranged between the plurality of wheels and extending in an up-down direction, and an elastic member, wherein the omnidirectional drive wheel can be driven along any direction in a plane perpendicular to the up-down direction, and the caster shaft is supported by the elastic member with an elastic force in the up-down direction. Effect of the Invention

[0006] According to the present invention, it is possible to provide a drive unit that can realize stable driving. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a drive unit. [Diagram 2] FIG. 2 is a side view of the drive unit. [Diagram 3] FIG. 3 is a front view of the drive unit. [Figure 4] FIG. 4 is a perspective view of an omnidirectional drive wheel. [Diagram 5] FIG. 5 is a vertical cross-sectional view of the caster portion. [Figure 6] FIG. 6 is a side view of the dolly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, exemplary embodiments of the present application will be described with reference to the drawings. In this application, the shape and positional relationship of each part will be described with the direction in which the caster shaft 32 described later extends being the "vertical direction". However, the definition of the vertical direction is not intended to limit the orientation of the drive unit or cart according to the present invention when in use. In this application, the "parallel direction" also includes a substantially parallel direction, and the "orthogonal direction" also includes a substantially orthogonal direction.

[0009] FIG. 1 is a perspective view of the drive unit 1. FIG. 2 is a side view of the drive unit 1. FIG. 3 is a front view of the drive unit 1. The drive unit 1 shown in FIG. 1, FIG. 2, and FIG. 3 runs on a floor surface or the ground. The drive unit 1 has a support member 11, omnidirectional drive wheels 2, and caster portions 3.

[0010] The support member 11 supports the caster portion 3 and the omnidirectional drive wheels 2. In this embodiment, the drive unit 1 has two omnidirectional drive wheels 2. The two omnidirectional drive wheels 2 are connected to a single axle 23. This allows the drive unit 1 to travel more stably along any direction in a plane perpendicular to the up-down direction. The drive unit 1 has two caster portions 3. In the examples of FIGS. 1, 2, and 3, the support member 11 is made of a flat plate-shaped member. However, the shape of the support member 11 is not particularly limited.

[0011] The two caster parts 3 are located between the two omnidirectional driving wheels 2 in the longitudinal direction of the axle 23. The two caster parts 3 are located outside the two omnidirectional driving wheels 2 in the lateral direction of the axle 23 with the axle 23 as a reference. That is, one of the two caster parts 3 is located on one side of the lateral direction of the axle 23 with the axle 23 as a reference, and the other of the two caster parts 3 is located on the other side of the lateral direction of the axle 23 with the axle 23 as a reference. Also, as shown in FIG. 1 and FIG. 2, one of the two caster parts 3 is located on one side of the omnidirectional driving wheel 2 in the lateral direction of the axle 23 with the axle 23 as a reference, and the other of the two caster parts 3 is located on the other side of the omnidirectional driving wheel 2 in the lateral direction of the axle 23 with the axle 23 as a reference. This allows the entire drive unit 1 to stably contact the floor surface or the ground. Therefore, more stable running is possible.

[0012] 4 is a perspective view of the omnidirectional drive wheel 2. The omnidirectional drive wheel 2 can be driven in any direction on a plane perpendicular to the up-down direction. The omnidirectional drive wheel 2 has a wheel 21 and a plurality of rotors 22.

[0013] The multiple rotating bodies 22 are rotatable in a direction intersecting the circumferential direction of the wheel 21. The multiple rotating bodies 22 are arranged side by side in the circumferential direction of the wheel 21. The multiple rotating bodies 22 are made of, for example, rubber.

[0014] For example, the core body 24 is disposed on the outer circumferential surface of the wheel 21. The core body 24 has an annular shape extending along the circumferential direction of the wheel 21. Each of the multiple rotating bodies 22 has a cylindrical shape, and the multiple rotating bodies 22 are rotatably supported by the core body 24. The outer circumferential surfaces of the multiple rotating bodies 22 supported by the core body 24 form a circular outer periphery of the omnidirectional drive wheel 2. This allows the omnidirectional drive wheel 2 to rotate by sequentially bringing the outer circumferential surfaces of the multiple rotating bodies 22 into contact with the floor surface or the ground.

[0015] Each omnidirectional drive wheel 2 is provided with a wheel drive unit such as a motor that can control the rotation direction and rotation speed. Each omnidirectional drive wheel 2 can be rotated in the forward or reverse direction independently by the wheel drive unit.

[0016] 5 is a vertical cross-sectional view of the caster unit 3. The caster unit 3 has a plurality of wheels 31, a caster shaft 32, an elastic member 33, an adjustment nut , and a mounting block .

[0017] The wheels 31 face each other with a gap therebetween. The caster shaft 32 is disposed between the wheels 31. More specifically, the wheels 31 face each other with a gap therebetween in the longitudinal direction of the axle 23, and the caster shaft 32 is disposed at the middle of the wheels 31 in the longitudinal direction of the axle 23. The caster shaft 32 extends in the vertical direction. The caster shaft 32 is supported by the elastic member 33 with elasticity in the vertical direction. At least a part of the elastic member 33 is disposed above the wheels 31. In this embodiment, the elastic member 33 is a suspension spring. However, the elastic member 33 may be a member having elasticity other than a suspension spring. The adjustment nut 34 contacts the upper end of the elastic member 33. The mounting block 35 is disposed above the adjustment nut 34. For example, the mounting block 35 is attached to the support member 11 by screwing, and the caster portion 3 is supported by the support member 11.

[0018] The adjustment nut 34 adjusts the elastic force of the elastic member 33. The adjustment nut 34 can adjust the elastic force of the elastic member 33 to an adjusted load. The adjusted load is a load at which the wheel 31 does not slip between the floor surface or the ground, and the support member 11 can move without tilting relative to the floor surface or the ground. The adjustment nut 34 can adjust the elastic force of the elastic member 33 to an appropriate elastic force depending on the load placed on the support member 11.

[0019] In this embodiment, the caster part 3 has a plurality of wheels 31, and the plurality of wheels 31 face each other with a gap therebetween. Since the axis that is the center of rotation of the caster part 3 is located between the plurality of wheels 31, the amount of rotation required when switching between forward and backward movement is smaller than that of a single-wheel type wheel. Therefore, compared to a single-wheel type wheel, when switching between forward and backward movement, the drive unit 1 does not swing significantly in a direction perpendicular to the up-down direction. In addition, a stable change of direction can be realized when moving in a free direction. In particular, when the drive unit 1 has an omnidirectional drive wheel 2, the drive unit 1 can move in any direction on a plane perpendicular to the caster shaft 32. However, for example, when the caster part is composed of a single-wheel type wheel, the above-mentioned mechanism may cause the drive unit 1 to swing significantly in a direction perpendicular to the up-down direction, for example, when switching between forward and backward movement. On the other hand, in the configuration of this embodiment, the drive unit 1 can stably change direction in a free direction, which is particularly useful for a drive unit 1 having an omnidirectional drive wheel 2.

[0020] When the wheel 31 is not subjected to a downward elastic force by the elastic member 33, the omnidirectional drive wheel 2 is also not subjected to a downward elastic force by the elastic member 33. In that case, the rotational force of the omnidirectional drive wheel 2 tends to be greater than the frictional force with the floor or ground, making it more likely to slip. However, when the elastic member 33 biases the caster shaft 32 in the vertical direction, a downward elastic force is applied to the wheel 31 and the omnidirectional drive wheel 2. As a result, slipping is less likely to occur than when the downward elastic force by the elastic member 33 is not applied, and stable running is possible.

[0021] Fig. 6 is a side view of the dolly 4. The dolly 4 has a top plate 41 and a housing 42. In Fig. 6, the dolly 4 is shown in a simplified form.

[0022] In this embodiment, the drive unit 1 is used in a cart 4. The cart 4 is an automated guided vehicle. The drive unit 1 is housed in a housing 42. For example, the drive unit 1 contacts the inside of the housing 42 and is attached to the housing 42 by screwing. The top plate 41 is disposed on the upper part of the housing 42. The support member 11 may also serve as the top plate 41.

[0023] It is preferable that the cart 4, which is an unmanned guided vehicle, can at least switch between forward and reverse. According to the configuration of this embodiment, it is possible to smoothly switch between forward and reverse by wireless communication or automatic control, and the cart 4 does not swing significantly in a direction perpendicular to the up-down direction when switching between forward and reverse. Therefore, even when switching between forward and reverse, smooth and stable running is possible. In addition, stable direction changes can be realized when moving in any direction.

[0024] For example, the cart 4, which is an unmanned guided vehicle, receives travel commands from a user via a terminal device by wireless communication to instruct the cart 4 to move in each direction. The cart 4 travels within the movement space according to the travel commands. An example of the terminal device is a tablet computer. The user can operate the terminal device to send a travel command to the cart 4 to switch between forward and reverse movement.

[0025] The cart 4, which is an automated guided vehicle, and the terminal device can be connected one-to-one, for example, to communicate in accordance with the Bluetooth (registered trademark) standard. The cart 4 and the terminal device can also communicate in accordance with Wi-Fi (registered trademark) using one or more access points.

[0026] Furthermore, the cart 4, which is an unmanned transport vehicle, may switch between forward and reverse travel by automatic control without a travel command from the user, using a program stored before the cart starts traveling and various sensors.

[0027] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the scope of the present invention. The drawings are mainly schematic illustrations of each component for ease of understanding, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual ones due to the convenience of drawing. In addition, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples, and are not particularly limited, and various modifications are possible within a scope that does not substantially deviate from the effects of the present invention.

[0028] In the above embodiment, the drive unit 1 is used in a dolly. The dolly is an unmanned guided vehicle. However, the drive unit 1 is not limited to being used in dollies, and can be applied to any moving body that moves on a floor or ground. The moving body may be, for example, a one-wheeled vehicle, a two-wheeled vehicle, a three-wheeled vehicle, or a four-wheeled vehicle. The moving body may have one drive unit 1, or may have two or more drive units 1. When using the drive unit in a dolly, the dolly does not have to be an unmanned guided vehicle.

[0029] In the above embodiment, the elastic member 33 is a suspension spring. However, the elastic member 33 may be a member having other elasticity.

[0030] In the above embodiment, the drive unit 1 has two omnidirectional drive wheels 2 and two caster units 3. However, the drive unit 1 may have only one omnidirectional drive wheel 2 and two or four caster units 3. This can reduce the number of omnidirectional drive wheels 2. This can contribute to making the drive unit 1 smaller and lighter, and reducing manufacturing costs. In addition, the drive unit 1 may have two omnidirectional drive wheels 2 and four caster units 3. This can enable more stable running.

[0031] The present technology can also adopt the following configuration.

[0032] (1) A caster part; Omnidirectional drive wheels; A support member for supporting the caster portion and the omnidirectional drive wheel; having The caster portion is A plurality of wheels opposed to each other with a gap therebetween; A caster shaft disposed between the plurality of wheels and extending in the vertical direction; An elastic member; having The omnidirectional drive wheel is capable of being driven along any direction in a plane perpendicular to the up-down direction, A drive unit, wherein the caster shaft is supported by the elastic member with elastic force in the vertical direction.

[0033] (2) The vehicle has two omnidirectional drive wheels; The drive unit described in (1) above, wherein the two omnidirectional drive wheels are connected to a single axle.

[0034] (3) The caster has two caster parts, The two caster portions are located between the two omnidirectional drive wheels in the longitudinal direction of the axle, The drive unit described in (2), wherein the two caster portions are located outboard of the two omnidirectional drive wheels in a short direction of the axle, with the axle as a reference.

[0035] (4) One of the two caster portions is disposed on one side of the short side direction based on the axle, The other of the two caster portions is positioned on the other side of the short side direction based on the axle.

[0036] (5) One of the two caster portions is disposed on one side of the omnidirectional drive wheel in the short side direction with respect to the axle, The other of the two caster portions is positioned on the other side of the omnidirectional driving wheel in the short direction relative to the axle.

[0037] (6) The caster portion further includes an adjustment nut that contacts an upper end of the elastic member, The drive unit according to any one of (1) to (5), wherein the adjustment nut is capable of adjusting the elastic force of the elastic member.

[0038] (7) The omnidirectional drive wheels are Wheels, A plurality of rotating bodies; having The plurality of rotating bodies rotatable in a direction intersecting the circumferential direction of the wheel are arranged side by side in the circumferential direction of the wheel, The drive unit according to any one of (1) to (6), wherein the outer periphery of the omnidirectional drive wheel is formed by the outer periphery of the plurality of rotating bodies.

[0039] (8) The vehicle has only one omnidirectional drive wheel; The drive unit according to any one of (1), (6), and (7), having two or four caster portions.

[0040] (9) A cart equipped with a drive unit described in any one of (1) to (8).

[0041] (10) The cart is an automated guided vehicle, The bogie described in (9) above is switchable between forward and reverse motion. [Industrial Applicability]

[0042] The present application can be used for drive units and carriages. [Explanation of symbols]

[0043] 1 Drive unit 11 Support member 2 Omni-directional driving wheels 21 Wheels 22 Rotating Body 23 Axle 24 Core body 3 Caster part 31 wheels 32 Caster shaft 33 Elastic Members 34 Adjustment nut 35 Mounting block 4 Carts 41 Tabletop 42 Case

Claims

1. Caster section and Omnidirectional drive wheels; A support member for supporting the caster portion and the omnidirectional drive wheel; having The caster portion is A plurality of wheels opposed to each other with a gap therebetween; A caster shaft disposed between the plurality of wheels and extending in the vertical direction; An elastic member; having The omnidirectional drive wheel is capable of being driven along any direction in a plane perpendicular to the up-down direction, A drive unit, wherein the caster shaft is supported by the elastic member with elastic force in the vertical direction.

2. The vehicle has two omnidirectional drive wheels, 2. The drive unit of claim 1, wherein the two omnidirectional drive wheels are connected to a single axle.

3. The caster has two caster parts, The two caster portions are located between the two omnidirectional drive wheels in the longitudinal direction of the axle, The drive unit according to claim 2 , wherein the two caster portions are positioned outward of the two omnidirectional drive wheels with respect to the axle in a short direction of the axle.

4. One of the two caster portions is disposed on one side of the short side direction based on the axle, The drive unit according to claim 3 , wherein the other of the two caster portions is disposed on the other side in the short direction with respect to the axle.

5. One of the two caster portions is disposed on one side of the omnidirectional drive wheel in the short side direction with respect to the axle; The drive unit according to claim 4 , wherein the other of the two caster portions is disposed on the other side in the short side direction of the omnidirectional drive wheel with respect to the axle.

6. The caster portion further includes an adjustment nut that contacts an upper end of the elastic member, The drive unit according to claim 5 , wherein the adjustment nut is capable of adjusting the elastic force of the elastic member.

7. The omnidirectional drive wheel is Wheels, A plurality of rotating bodies; having The plurality of rotating bodies rotatable in a direction intersecting the circumferential direction of the wheel are arranged side by side in the circumferential direction of the wheel, The drive unit according to claim 6 , wherein the outer periphery of the omnidirectional drive wheel is formed by the outer periphery of the plurality of rotating bodies.

8. The vehicle has only one omnidirectional drive wheel; The drive unit according to claim 1 , comprising two or four of the caster parts.

9. A bogie comprising a drive unit according to any one of claims 1 to 8.

10. The cart is an automated guided vehicle, 10. The bogie according to claim 9, which is switchable between forward and reverse travel.

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