Traveling wheel assembly for ground transport trolley, traveling mechanism and ground transport trolley

Abstract

According to the walking wheel assembly for the ground transportation trolley, the walking mechanism and the ground transportation trolley, the wheel pressure can be adjusted, and walking stability is ensured. The ground transportation trolley comprises a fixing part, and the walking wheel assembly for the ground transportation trolley comprises walking wheels; the wheel cover is fixedly connected with the fixing part; the supporting piece is connected to the fixing part in a manner of being capable of moving up and down and is used for supporting the walking wheel to be capable of rotating; the pressurizing device comprises a first elastic component, and the bottom end of the first elastic component is supported on the supporting piece; the movable piece can move downwards relative to the wheel cover so as to apply force to the top end of the first elastic component to enable the first elastic component to be compressed and deformed, and therefore the ground pressure of the walking wheel is increased through the supporting piece; and a pressurizing driving source for driving the movable member to move.

Description

Technical Field

[0001] This utility model relates to a walking wheel assembly, a walking mechanism, and a ground transport trolley for use in ground transport trolleys. Background Technology

[0002] Existing ground transport vehicles use springs (traditional suspension) to adjust the pressure on the drive wheels in order to keep them in contact with the ground. In this structure, the spring force cannot exceed the vehicle's own weight; if the spring force is too large, the vehicle will lift up. On the other hand, when the load is very heavy, the vehicle will not be able to move normally because the pressure between the drive wheels and the ground is insufficient (the springs do not provide enough wheel pressure under heavy load). Utility Model Content

[0003] This invention was made in view of the above-mentioned problems, and its purpose is to provide a walking wheel assembly, a walking mechanism, and a ground transport trolley with adjustable wheel pressure to ensure walking stability.

[0004] The first aspect of this utility model provides a wheel assembly for a ground transport vehicle, the ground transport vehicle including a fixed part, the wheel assembly including: a wheel; a wheel cover fixedly connected to the fixed part; a support member movably connected to the fixed part and supporting the wheel to rotate; and a pressurizing device including: a first elastic member, the bottom end of the first elastic member supported by the support member; a movable member movable relative to the wheel cover to apply force to the top end of the first elastic member to compress and deform the first elastic member, thereby increasing the ground pressure of the wheel via the support member; and a pressurizing drive source for driving the movable member to move.

[0005] The walking wheel assembly for a ground transport vehicle according to this utility model can adjust the compression of the first elastic member by adjusting the vertical position of the movable part, thereby controlling the wheel pressure (i.e., the pressure on the ground). It can adapt to greater load changes and provides a walking wheel assembly with adjustable wheel pressure and ensures walking stability.

[0006] In one embodiment, the pressurizing device includes a linear actuator that directly or indirectly converts the rotational motion of the motor, which serves as the pressurizing drive source, into the up-and-down motion of the movable member, thereby compressing or releasing the first elastic member. The linear actuator enables high-precision, high-speed displacement control.

[0007] In one embodiment, the linear actuator includes: a lead screw rotatably supported on the wheel cover and driven to rotate by the motor; and a nut screwed onto the lead screw, the nut being fixed to the movable member, wherein the first elastic member is an elastic member with a cavity, and the lead screw is inserted into the cavity. According to the above structure, the cavity of the first elastic member can be fully utilized in the linear actuator, which is beneficial for miniaturization of the pressurization device.

[0008] In one embodiment, the pressurizing device includes a sprocket and chain drive mechanism, which comprises: a driving sprocket connected to the output end of the motor; a driven sprocket connected to the top end of the lead screw; and a chain cooperating with the driving sprocket and the driven sprocket. According to this structure, for example, compared to the case where the output end of the motor is directly connected to the top end of the lead screw, the vertical dimension of the pressurizing device can be reduced.

[0009] In one embodiment, a groove is formed between the nut and the movable member, or on the movable member, the groove opening downwards, and the top end of the first elastic member is located in the groove. According to the above structure, the top end of the first elastic member can be limited, preventing deviation of the top end of the first elastic member, and enabling the movable member to reliably apply force to the top end of the first elastic member.

[0010] In one embodiment, the wheel assembly for the ground transport vehicle further includes a pressure plate fixedly connected to the support portion, the bottom end of the first elastic member being supported by the pressure plate, and the pressure plate having an upwardly protruding cylindrical portion inserted into the cavity. According to the above structure, the bottom end of the first elastic member can be limited, preventing deviation of the bottom end of the first elastic member and reliably supporting the bottom end of the first elastic member.

[0011] In one embodiment, the pressure plate has a wall portion, and the cylindrical portion is positioned opposite the wall portion, separated by the first elastic member, in a direction perpendicular to the vertical direction. According to this structure, the bottom end of the first elastic member can be reliably supported further.

[0012] In one embodiment, the movable member has an anti-rotation portion, and the pressurizing device further includes a guide member that guides the vertical movement of the movable member, the guide member contacting the anti-rotation portion in a manner that prevents the movable member from rotating. According to the above structure, rotation of the nut and the movable member can be restricted, allowing them to move smoothly in the vertical direction.

[0013] In one embodiment, the walking wheel assembly further includes a wheel drive source that drives the walking wheels to rotate. By providing a pressurizing device to the drive wheels, the pressurization effect is better compared to providing it to the non-drive wheels.

[0014] In one embodiment, the aforementioned wheel assembly further includes a second elastic member, the bottom end of which is supported by the support member and the top end of which is supported by the wheel cover. The second elastic member applies a downward force to the support member through compression deformation. According to this structure, for example, when the ground transport trolley using the wheel assembly is empty, the required wheel pressure can be provided by the compressed second elastic member, reducing the load on the pressurizing device.

[0015] In one embodiment, at least one of the first elastic member and the second elastic member is a spring.

[0016] A second aspect of this utility model provides a walking mechanism, including any of the above-mentioned walking wheel assemblies for ground transport vehicles.

[0017] According to the second aspect of the present invention, the walking mechanism can achieve good ground adaptability and walking stability through the walking wheel assembly.

[0018] In one embodiment, the walking mechanism further includes a caster wheel supported on the fixed part, and the walking wheel assembly further includes a wheel drive source that drives the walking wheel to rotate.

[0019] A third aspect of this utility model provides a ground transport vehicle, including any of the above-mentioned wheel assemblies for ground transport vehicles, or including any of the above-mentioned walking mechanisms.

[0020] According to a third aspect of the present invention, a ground transport vehicle is provided, which can achieve good ground adaptability and walking stability through a walking wheel assembly.

[0021] In one embodiment, the aforementioned ground transport vehicle further includes: a first sensor that detects the load weight of the ground transport vehicle; and a control unit that receives a first signal related to the load weight of the ground transport vehicle detected by the first sensor, determines the required movement distance of the movable member based on the first signal, and drives the pressure drive source to move the movable member downward by the required movement distance. According to the above structure, adjustments can be automatically made based on the load, and the pressure drive source can be driven based on the load weight of the ground transport vehicle to compress the first elastic member, providing appropriate elastic force to achieve the required wheel pressure.

[0022] In one embodiment, the aforementioned ground transport trolley includes a limiting mechanism disposed on at least one of the movable member, the wheel cover, and the fixed portion, the limiting mechanism being configured to restrict the movable member from moving downward beyond a predetermined position. By providing the limiting mechanism, abnormalities caused by the movable member moving downward beyond the predetermined position can be avoided.

[0023] In one embodiment, the limiting mechanism includes: a control unit that controls the operation of the pressure drive source; a trigger plate disposed on the movable member and moving together with it; and a second sensor fixed to the wheel cover or the fixing part via a bracket and located below the trigger plate. When the trigger plate moves to a distance less than a predetermined distance from the second sensor and triggers the second sensor, the second sensor sends a second signal to the control unit. Upon receiving the second signal, the control unit causes the pressure drive source to stop operating. According to the above structure, when the movable member attempts to move downwards beyond a predetermined position, the second sensor is triggered, which can promptly stop the operation of the pressure drive source and prevent abnormalities. Attached Figure Description

[0024] Figure 1 This is a perspective view showing a walking mechanism according to an embodiment of the present invention.

[0025] Figure 2 From and Figure 1 A three-dimensional view of the walking mechanism from different angles.

[0026] Figure 3 This is a perspective view showing a walking wheel assembly according to an embodiment of the present invention.

[0027] Figure 4 This is an exploded perspective view showing a walking wheel assembly according to an embodiment of the present invention.

[0028] Figure 5 This is a perspective view showing the wheel cover and pressurizing device of a walking wheel assembly according to an embodiment of the present invention.

[0029] Figure 6 This is an exploded perspective view showing the wheel cover and pressurizing device of a walking wheel assembly according to an embodiment of the present invention.

[0030] Figure 7 This is a cross-sectional perspective view showing the wheel cover and pressurizing device of a walking wheel assembly according to an embodiment of the present invention.

[0031] Figure 8 This is a cross-sectional perspective view showing the wheel cover and pressurizing device of a walking wheel assembly according to an embodiment of the present invention.

[0032] (Symbol Explanation)

[0033] 1. Walking wheel assembly

[0034] 3 swivel wheels

[0035] 4. Pressurization device

[0036] 7 Second elastic member

[0037] 11 walking wheels

[0038] 12 wheel covers

[0039] 13 support components

[0040] 14-wheel drive source

[0041] 15 Pressure Plates

[0042] 21 base section

[0043] 41 First elastic member

[0044] 42 movable parts

[0045] 43 Pressure Drive Source

[0046] 48 guides

[0047] 61 lead screw

[0048] 65 nuts

[0049] 91 trigger pieces

[0050] 92 Second Sensor

[0051] 151 concavity

[0052] 152 cylinder section

[0053] 422 protrusion

[0054] 1511 wall section

[0055] S-groove Detailed Implementation

[0056] Hereinafter, with reference to the accompanying drawings, the technical solutions of embodiments and modifications of this utility model will be described. Furthermore, the scope of this utility model is not limited to the following embodiments and modifications, and can be arbitrarily modified within the scope of the technical concept of this utility model. In addition, in the following drawings, for ease of understanding of the structures, the actual construction may sometimes differ from the scale, quantity, etc., in each construction. Furthermore, the same or equivalent parts in the drawings are labeled with the same reference numerals and will not be repeatedly explained.

[0057] <First Embodiment>

[0058] The walking mechanism 100 involved in the first embodiment will be described below.

[0059] In the diagram, for ease of understanding, the intersecting Z, X, and Y directions are appropriately shown.

[0060] The Z-direction is defined based on the following state: the ground transport vehicle with the walking mechanism 100 is positioned on the ground in a usable manner. The Z-direction is the vertical direction of the ground transport vehicle. The X-direction is, for example, the direction parallel to the axis of rotation of the walking wheels 11.

[0061] The Z-direction side and the other side are also referred to as Z-direction side Z1 and Z-direction side Z2. In this embodiment, Z-direction side Z1 and Z-direction side Z2 are the top and bottom of the ground transport vehicle in use.

[0062] The X-direction and the other side are also referred to as X-direction side X1 and X-direction side X2. In this embodiment, in the ground transport vehicle in use, the X-direction is the direction perpendicular to the up and down direction.

[0063] The Y-direction and the other direction are also referred to as Y1 and Y2, respectively. In this embodiment, in the ground transport vehicle in use, the Y-direction is the direction perpendicular to the up-down direction and the X-direction (pickup direction). Furthermore, in this specification, "parallel direction" also includes generally parallel directions, and "perpendicular direction" also includes generally perpendicular directions.

[0064] The "fixed part" of this utility model is a part of the walking wheel assembly on the ground transport vehicle, serving as a reference for the relative movement of the components in the walking wheel assembly. The fixed part is not necessarily a single component; for example, it can be a combination of multiple components that are fixed relative to each other, or it can be different parts of a single component. For example, the "base part 21" in the first embodiment is a fixed part.

[0065] (Simplified structure of the ground transport vehicle)

[0066] Figure 1 This is a perspective view showing the walking mechanism 100 of the first embodiment of the present invention. Figure 2 From and Figure 1 A three-dimensional view of the walking mechanism 100 from different angles. Figure 3 This is a perspective view showing the walking wheel assembly 1 of the walking mechanism 100. Figure 4 This is an exploded perspective view showing the walking wheel assembly 1. Figure 5 This is a perspective view showing the wheel cover and pressurization device of the walking wheel assembly 1. Figure 6 This is an exploded perspective view showing the wheel cover 12 and the pressurizing device 4 of the walking wheel assembly 1. Figure 7 This is a cross-sectional perspective view showing the wheel cover 12 and the pressurizing device 4 of the walking wheel assembly 1. Figure 8 This is a cross-sectional perspective view showing the wheel cover 12 and the pressurizing device 4 of the walking wheel assembly 1.

[0067] The traveling mechanism 100 can be applied, for example, to a ground transport vehicle for transporting goods. The traveling mechanism 100 includes a traveling wheel assembly 1, a chassis 2, and casters 3.

[0068] The wheel assembly 1 and the casters 3 are supported on the chassis 2. The shape of the chassis is not particularly limited; for example, it can be cuboid. The chassis 2 includes a base portion 21, and may also include a top plate (not shown) covering the base portion 21 from above, and a side plate (not shown) connecting the edge of the base portion 21 to the edge of the top plate. That is, the base portion 21 is part of the chassis 2. Furthermore, the chassis 2 may also have a notch opening in at least one direction, a through portion extending vertically, etc. A storage space is formed inside the chassis 2. Part of the wheel assembly 1 and the casters 3 are stored in the storage space of the chassis 2. In addition, the storage space of the chassis 2 can store control components for movement, a power module, etc.

[0069] The installation positions of the wheel assembly 1 and the caster wheel 3 in the chassis 2 are not particularly limited. In the walking mechanism 100 of this embodiment, two wheel assemblies 1 are arranged in the middle part of the chassis 2 in the Y direction along the X direction, and caster wheels 3 are respectively provided on one side Y1 and the other side Y2 of the Y direction for each wheel assembly 1. The base part 21 includes: a base plate 211, which is generally plate-shaped with its thickness along the vertical direction; and a wall 212 extending upward from the base plate 211. In this embodiment, each wheel assembly 1 is provided with walls 212, 212 opposite each other in the Y direction.

[0070] (Walking wheel assembly)

[0071] In this embodiment, the two walking wheel assemblies 1 have the same structure. Hereinafter, the structure of the walking wheel assembly 1 will be described using the walking wheel assembly 1 located in the X direction X1 as an example.

[0072] The walking wheel assembly 1 includes a walking wheel 11, a wheel cover 12, a support 13, a motor 14, and a pressurizing device 4.

[0073] The traveling wheel 11 is located on the X1 side of the second plate 133 in the X direction, as described later, and is rotatably supported on the second plate 133. For example, the axle of the traveling wheel 11 is rotatably supported on the second plate 133 via a bearing (not shown). That is, the support member 13 supports the traveling wheel 11 so that it can rotate.

[0074] The traveling wheel 11 has an axle (not shown) connected to the output of a motor 14, which serves as the wheel drive source. The traveling wheel 11 is driven to rotate by the motor 14. The motor 14 can be a servo motor, a brushless motor, a stepper motor, etc.

[0075] The wheel cover 12 is fixed to the corresponding wall 212, 212 by means of fastening with fasteners such as screws or welding, thereby being fixedly connected to the base part 21.

[0076] The support member 13 includes: a pair of first plates 131 and 132 disposed opposite each other in the Y direction; a second plate 133 fixedly disposed between the side plates 131 and 132; a bent portion 134 bending from the lower end of the first plate 131 toward the side of the first plate 132 (the Y2 side in the opposite Y direction); and a bent portion 135 bending from the lower end of the first plate 132 toward the side of the first plate 131 (the Y1 side in the Y direction). The second plate 133 is plate-shaped with its thickness direction along the X direction. The wheel drive source 14 is mounted on the X2 side of the second plate 133 in the opposite X direction. The bent portions 134 and 135 are located above the lower end of the traveling wheel 11.

[0077] The support member 13 is located below the wheel cover 12. The support member 13 is movably connected to the base portion 21. In this embodiment, the support member 13 is connected to the base portion 21 via a hinge mechanism 5. However, it is not limited to this; a connection structure other than the hinge mechanism 5 can also be used to movably connect the support member 13 to the base portion 21.

[0078] The hinge mechanism 5 includes: a pair of seats 51, 51 arranged opposite each other in the Y direction and fixed to the base 21; two shafts 52, 53 disposed between the pair of seats 51; rocker arms 54, 55 whose base ends (near the ends of the seats 51, 51) are connected to the shafts 52; and rocker arms 56, 57 whose base ends are connected to the shafts 53. The pair of seats 51, 51 are fixed to the upper surface of the base plate 211, for example, by fasteners such as screws. The two shafts 52, 53 are arranged vertically parallel between the pair of seats 51, 51. The two shafts 52, 53 are each cylindrical, extending in the Y direction. The rocker arms 54 to 57 extend in a direction perpendicular to the Y direction.

[0079] The front ends (ends away from the seats 51, 51) of each of the swing arms 54 to 57 are hinged to the first plates 131, 132 of the support member 13 in a swingable manner. The base ends of the swing arms 54 and 55 are swingably supported on the seats 51, 51 via the shaft 52, and the base ends of the swing arms 56 and 57 are swingably supported on the seats 51, 51 via the shaft 53. Thus, the support member 13 is vertically movable and connected to the base portion 21. For example, the two ends of each shaft portion 52, 53 in the Y direction are rotatably supported on the seats 51, 51, respectively. The base ends of the swing arms 54 and 55 are fixed to the shaft portion 52, and the base ends of the swing arms 56 and 57 are fixed to the shaft portion 53. Alternatively, the two ends of each shaft portion 52 and 53 in the Y direction can be fixedly supported on the base portion 51 and 51 respectively, the base ends of the swing rods 54 and 55 can be rotatably supported on the shaft portion 52 around the axis of the shaft portion 52, and the base ends of the swing rods 54 and 55 can be rotatably supported on the shaft portion 53 around the axis of the shaft portion 53.

[0080] (Pressure device)

[0081] The pressurizing device 4 includes a first elastic member 41, a movable member 42, and a pressurizing drive source 43.

[0082] The bottom end of the first elastic member 41 is supported by the support member 13. The movable member 42 is located above the first elastic member 41 and abuts against the top end of the first elastic member 41. The movable member 42 is driven by the pressure drive source 43, so that the movable member 42 can move downward relative to the wheel cover 12 to apply force to the top end of the first elastic member 41, causing the first elastic member 41 to compress and deform, thereby increasing the ground pressure of the walking wheel 11 through the support member 13.

[0083] In this embodiment, the pressure drive source 43 is a motor, the first elastic member 41 is a spring, and the pressure device 4 includes a linear actuator. The linear actuator directly or indirectly, via a transmission mechanism, converts the rotational motion of the motor (which is the pressure drive source 43) into the up-and-down movement of the movable member 42, thereby compressing or releasing the spring 41. By compressing the spring 41, the traveling wheel 11 can be subjected to additional ground pressure. The motor 43 can be, for example, a servo motor.

[0084] The pressurizing device 4 also includes a first mounting plate 44. The motor 43 is fixedly connected to the bases 51, 51 via the first mounting plate 44. For example, the first mounting plate 44 is fixed to the housing of the motor 43 by fasteners such as screws, and is also fixed to the bases 51, 51 by fasteners such as screws.

[0085] The wheel assembly 1 also includes a pressure plate 15. The bottom end of the first elastic member 41 abuts against the upper surface of the pressure plate 15. The two sides of the pressure plate 15 in the Y direction are stacked on the bent portions 134 and 135 of the support member 13, and are fixedly connected to the bent portions 134 and 135 respectively by fasteners such as screws. Thus, the bottom end of the spring 41 is supported on the support member 13 by the pressure plate 15.

[0086] Furthermore, the pressure plate 15 has a downwardly recessed portion 151, and an upwardly protruding cylindrical portion 152 is provided in the recess 151. That is, the pressure plate 15 has an upwardly protruding cylindrical portion 152. The cylindrical portion 152 is a cylindrical shape with openings at the top and bottom. The through portion at the center of the cylindrical portion 152 allows the lead screw to pass through.

[0087] Furthermore, the cylinder 152 is inserted into the cavity of the spring 41. In other words, the lower part of the spring 41 is sleeved outside the cylinder 152.

[0088] The recess 151 has a wall portion 1511. That is, the pressure plate 15 has a wall portion 1511. In a direction perpendicular to the vertical direction (e.g., the Y direction), the cylindrical portion 152 is opposite to the wall portion 1511 via the spring 41. More specifically, the cylindrical portion 152 is radially inward of the wall portion 1511 of the recess 151, centered on the axis of the lead screw 61. The axis of the lead screw 61 is along the vertical direction. The bottom end portion of the spring 41 is located between the cylindrical portion 152 and the wall portion 1511 of the recess 151.

[0089] The linear actuator described above includes a lead screw 61, a transmission member 62, a second mounting plate 63, a bearing 64, and a nut 65. The lead screw 61 is, for example, a ball screw. The lead screw 61 is inserted into the cavity of the spring 41. Alternatively, the first elastic member 41 may also be other elastic members with cavities for the lead screw 61 to be inserted.

[0090] The transmission component 62 is located above the second mounting plate 63. The transmission component 62 is fixed to the top end of the lead screw 61, so that the lead screw 61 can rotate together with the transmission component 62.

[0091] In this example, the transmission component 62 is a driven sprocket. The pressurizing device 4 includes a sprocket and chain drive mechanism. The lead screw 61 is driven to rotate by the motor 43 through the sprocket and chain drive mechanism. The aforementioned sprocket and chain drive mechanism includes: a driving sprocket 45 connected to the output end of the motor 43; a driven sprocket 62 connected to the top end of the lead screw 61; and a chain 46 that engages with the driving sprocket 45 and the driven sprocket 62. The driving sprocket 45 and the driven sprocket 62 are each configured to rotate about an axis in the vertical direction. The chain 46 meshes with the driving sprocket 45 and the driven sprocket 62 respectively. The driving sprocket 45 is driven to rotate by the motor 43, and the driving sprocket 45 transmits power to the driven sprocket 62 via the chain 46, causing the driven sprocket 62 to rotate.

[0092] The second mounting plate 63 is plate-shaped with its thickness extending vertically. The second mounting plate 63 has a first through hole 631 extending through its thickness. A bearing 64 is disposed within the first through hole 631. The bearing 64 allows the lead screw 61 to be rotatably supported on the second mounting plate 63. The lead screw 61 is restricted by the bearing 62, allowing it to only perform rotational movements. Furthermore, the second mounting plate 63 is fixed to the upper surface of the wheel cover 12 by fasteners such as screws. Thus, the lead screw 61 is rotatably supported on the wheel cover 12.

[0093] The wheel cover 12 has a second through hole 121 at a position corresponding to the first through hole 631, through which the lead screw 61 and the like pass.

[0094] Nut 65 is screwed into lead screw. In this embodiment, nut 65 has a large diameter portion 651 and a small diameter portion 652. The small diameter portion 652 is located below the large diameter portion 651, and the outer diameter of the small diameter portion 652 is smaller than the outer diameter of the large diameter portion 651.

[0095] Nut 65 is fixed to movable member 62. When nut 65 moves up and down due to the rotation of lead screw 61, movable member 62 moves together with nut 65.

[0096] The movable member 42 has a rectangular outer contour when viewed in the vertical direction. The movable member 42 has an annular portion 421 surrounding the small-diameter portion 652 of the nut 65, and the annular portion 421 has a rectangular outer contour when viewed in the vertical direction. The upper surface of the annular portion 421 contacts the lower surface of the large-diameter portion 651. The annular portion 421 and the large-diameter portion 651 are fixed by fasteners such as screws.

[0097] The movable member 42 abuts against the tip of the spring 41 on the lower surface of the annular portion 421. The movable member 42 also has a protrusion 422. The protrusion 422 is provided to protrude downward from the edge of the annular portion 421. The protrusion 422 is generally rectangular annular. The protrusion 422 is radially outward relative to the small-diameter portion 652 of the nut 65 centered on the axis of the lead screw 61. The tip of the spring 41 is located between the small-diameter portion 652 of the nut 65 and the protrusion 422. That is, a groove S is formed between the nut 65 and the movable member 42. The groove S opens downward, and the tip of the spring 41 is located in the groove S. Alternatively, a downward-opening groove may be formed in the movable member 42, and the tip of the spring 41 may be located in the groove.

[0098] The pressurizing device 4 also includes guide members 48 that guide the vertical movement of the movable member 42. In this embodiment, two guide members 48 are provided in the Y direction, spaced apart from the movable member 42. By providing guide members 48, the rotation of the nut 65 and the movable member 42 can be restricted (the nut 65 cannot rotate but can only reciprocate axially in the lead screw 61), allowing it to move smoothly in the vertical direction. The vertical position of the movable member 42 can be adjusted by controlling the movement of the nut 65, thereby adjusting the compression of the spring 41 and achieving the purpose of controlling the wheel pressure.

[0099] Two guide members 48 are fixed to the wheel cover 12 at their top ends by fasteners such as screws. The movable member 42 has outer surface portions 422a and 422b facing the Y direction at its protrusion 422. The outer surface portions 422a and 422b function as anti-rotation portions. That is, the movable member 42 has an anti-rotation portion. The guide members 48 contact the outer surface portions 422a and 422b in a manner that prevents the movable member 42 from rotating. In this embodiment, the guide members 48 contact the outer surface portions 422a and 422b in a direction perpendicular to the vertical direction.

[0100] In this embodiment, the movable member 42 has a rectangular outer contour when viewed in the vertical direction. This rectangle has two opposite sides in the Y direction and two opposite sides in the X direction. In this embodiment, the two guide members 48 are respectively opposite to the two opposite sides of the rectangle in the Y direction. More specifically, the outer surface portions 422a and 422b of the protrusion 422 facing the Y direction form the two opposite sides of the rectangle in the Y direction. The two guide members 48 each have a guide surface 481 opposite to the outer surface portions 422a and 422b. The two guide members 48 guide the vertical movement of the movable member 42 via the guide surfaces 481. Furthermore, for example, a sliding partition 49 with low surface roughness can be provided between the movable member 42 and the guide members 48 to reduce friction when in contact with the guide surfaces 481. For example, the sliding partition 49 is fixed to the outer surface portions 422a and 422b. At this time, the guide surface 481 of the guide member 48 contacts the sliding partition 49, and the sliding partition 49 functions as an anti-rotation part. Furthermore, the number of guide members 48 is not particularly limited; there can be one or more. The anti-rotation part is not limited to a planar shape; it can also be curved.

[0101] In addition, the wheel assembly 1 also includes a second elastic member 7. The number of second elastic members 7 is not particularly limited; for example, four second elastic members 7 may be arranged around the wheel 11. The bottom end of each second elastic member 7 is supported by a support member 13, and the top end is supported by a wheel cover 12. In this embodiment, the bottom ends of two second elastic members 7 are supported by the support member 13 across a pressure plate 15. The second elastic members 7 exert a downward force on the support member 13 through compression deformation. The second elastic member 7 may be, for example, a spring. Alternatively, one or more second elastic members other than four may be arranged around the wheel 11.

[0102] The following is an example of the operation of the pressurizing device 4.

[0103] The motor 43 drives the drive sprocket 45 to rotate, and the drive sprocket 45 transmits power to the driven sprocket 62 via the chain 46, so that the driven sprocket 62 rotates together with the lead screw 61. When the lead screw 61 rotates in one or the other direction, under the action of the guide 48, the nut 65, which is fixed to the movable member 42, is restricted from rotating and can only move up and down. Thus, the up and down movement of the movable member 42 is realized.

[0104] In this embodiment, the motor, which serves as the pressure driving source 43, rotates at a certain angle, causing the first elastic member 41 to compress and provide appropriate elastic force. For example, if it is necessary to adjust and increase the wheel pressure, the motor, which serves as the pressure driving source 43, drives the lead screw 61 to rotate, causing the movable member 42 to move downwards, compressing the first elastic member 41, and providing greater wheel pressure for the traveling wheel 11.

[0105] The elastic force of the first elastic member 41 acts on the chassis 2 and the wheel assembly 1. By changing the position of the nut 65, the elastic force of the first elastic member 41 can be adjusted, making the ground pressure of the wheel 11 controllable. In addition, maintaining the position of the lead screw 61 can ensure the pressure provided by the first elastic member 41, which can be achieved by stopping the motor or adding a brake function.

[0106] In one example, the distance that the movable part 42 should move can be determined based on the load weight of the ground transport vehicle using the walking wheel assembly 1, and the pressure drive source 43 can be driven to move the movable part 42 downward by that distance.

[0107] For example, a ground transport vehicle includes: a first sensor (not shown) that detects the load weight of the ground transport vehicle; and a control unit (not shown) that controls the operation of a motor (pressure drive source) 43. The first sensor is a gravity sensor. The control unit receives a first signal related to the load weight of the ground transport vehicle detected by the first sensor, determines the required movement distance of a movable member based on the first signal, and drives the pressure drive source 43 to move the movable member 42 downward by the required movement distance. As an example, data of a pre-set value of the required movement distance corresponding to the load weight can be stored in the memory included in the control unit, and the required movement distance can be obtained by reading the data stored in the memory.

[0108] In this embodiment, a pressure device 4 and a plurality of second elastic members 7 are provided around the walking wheel 11. The first elastic member 41 and the second elastic member 7 are springs, respectively.

[0109] When the movable member 42 is empty, it contacts (aggregates) the top end of the uncompressed or compressed first elastic member 41.

[0110] When the vehicle is empty, the compressed second elastic member 7 (or the compressed second elastic member 7 and the compressed first elastic member 41) ensures the normal operation of the ground transport trolley. Under load, the pressurizing device 4 in the walking wheel assembly 1 can be activated according to the load weight, increasing the pressure to ensure the ground transport trolley operates normally under load. Thus, the ground pressure of the walking wheels 11 can be dynamically adjusted. When empty, the motor (pressurizing drive source) 43 does not need to operate; under load, the motor is controlled according to the actual weight to increase the ground pressure on the walking wheels 11, ensuring normal movement even under heavy loads.

[0111] Furthermore, the ground transport trolley includes a limiting mechanism 9 disposed on at least one of the movable member 42, wheel cover 12, and base portion 21. The limiting mechanism is configured to restrict the movable member 42 from moving downwards beyond a predetermined position. This limits the travel of the nut 65 in the wheel assembly 1, ensuring a fixed position each time it resets and preventing the motor from exceeding its predetermined travel, which could lead to structural damage or other abnormalities. For example, it can prevent motor overload caused by excessive downward travel of the movable member 42, and damage due to excessive compression of the first elastic member 41. Additionally, it can limit the travel of the nut 65; for example, when using a ball screw, if the travel exceeds the limit, the balls will fall out, causing abnormal screw operation.

[0112] In one example, the limiting mechanism includes the aforementioned control unit, trigger plate 91, and second sensor 92. Trigger plate 91 is fixedly mounted on movable member 42 and moves together with it. Second sensor 92 is fixed to wheel cover 12 via a bracket and is located below trigger plate 91. Second sensor 92 may be an inductive proximity switch sensor.

[0113] When the trigger plate 91 moves to a distance less than a specified distance from the second sensor 92 and triggers the second sensor 92, the second sensor 92 sends a second signal to the control unit. Upon receiving the second signal, the control unit causes the pressure drive source 43 to stop operating.

[0114] Sometimes, due to motor encoder malfunctions, assembly errors, or other reasons, the downward stroke of the movable part 42 may exceed the design range. In this embodiment, by setting a limit mechanism 9, when the movable part 42 attempts to move downward beyond the specified position, the second sensor 92 is triggered, which can stop the motor operation in time and avoid abnormalities.

[0115] Alternatively, a third sensor 93 can be installed, fixed to the wheel cover 12 via a bracket and located above the trigger plate 91. When the ground transport vehicle is unloaded, the trigger plate 91 triggers the third sensor 93, which puts the first elastic member 41 in a state of no pressure or low pressure.

[0116] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above embodiments and modifications.

[0117] For example, multiple pressurizing devices 4 can be provided around the walking wheel 11.

[0118] For example, the first elastic member 41 and the second elastic member 7 can also be elastic members other than springs. In addition, the second elastic member 7 can be omitted.

[0119] For example, the pressure drive source 43 can also be a hydraulic cylinder or an electric cylinder.

[0120] For example, the second sensor 92 can also be fixed to the base portion 21 via a bracket.

[0121] For example, the limit mechanism 9 can also use photoelectric sensors, limit switches, etc. to limit the downward movement of the movable part 42 beyond the specified position.

[0122] For example, a synchronous belt and synchronous pulley transmission mechanism can be used instead of a sprocket and chain transmission mechanism between the pressure drive source 43 and the linear driver.

[0123] For example, the pressurizing device can also be placed around the non-drive wheels (e.g., caster wheel 3).

[0124] The specific embodiments of this utility model have been described above in conjunction with the accompanying drawings. However, it is understood that the above description does not limit this utility model in any way, and the technical features of each embodiment can be combined with each other in any way to constitute new embodiments. Furthermore, those skilled in the art, after understanding the above specific embodiments, can make various other modifications and changes to this utility model as needed. These modifications and changes do not depart from the essential content of this utility model.

Claims

1. A walking wheel assembly for a floor transport trolley, the floor transport trolley comprising a fixed portion, characterised in that, include: Wheels; Wheel cover, the wheel cover being fixedly connected to the fixing part; A support member is movably connected to the fixed part and supports the traveling wheel so that it can rotate. as well as Pressurization device, The pressurizing device includes: A first elastic member, the bottom end of which is supported by the support member; A movable member, capable of moving downward relative to the wheel cover to apply force to the tip of the first elastic member, causing the first elastic member to compress and deform, thereby increasing the ground pressure of the wheel via the support member; and A pressure drive source that drives the movable part to move.

2. The wheel assembly for a ground transport vehicle according to claim 1, characterized in that, The pressurizing device includes a linear actuator, which directly or indirectly converts the rotational motion of the motor, which serves as the pressurizing drive source, into the up-and-down motion of the movable member, so as to compress or release the first elastic member.

3. The walking wheel assembly for a ground transport vehicle according to claim 2, characterized in that, The linear actuator includes: a lead screw rotatably supported on the wheel cover and driven to rotate by the motor; and a nut screwed onto the lead screw, the nut being fixed to the movable member. The first elastic member is an elastic member with a cavity, and the lead screw is inserted into the cavity.

4. The walking wheel assembly for a ground transport vehicle according to claim 3, characterized in that, The pressurizing device includes a sprocket and chain drive mechanism. The sprocket and chain drive mechanism includes: A drive sprocket, which is connected to the output end of the motor; Driven sprocket, the driven sprocket being connected to the top end of the lead screw; and A chain that cooperates with the driving sprocket and the driven sprocket.

5. The wheel assembly for a ground transport vehicle according to claim 3, characterized in that, A groove is formed between the nut and the movable member, or on the movable member, the groove opening downwards, and the top end of the first elastic member is located in the groove.

6. The wheel assembly for a ground transport vehicle according to claim 3, characterized in that, It also includes a pressure plate fixedly connected to the support portion, and the bottom end of the first elastic member is supported on the pressure plate. The pressure plate is provided with an upwardly protruding cylindrical portion. The cylindrical portion is inserted into the cavity.

7. The wheel assembly for a ground transport vehicle according to claim 6, characterized in that, The pressure plate is provided with a wall portion. In a direction perpendicular to the vertical direction, the cylindrical portion and the wall portion are opposite each other through the first elastic member.

8. The wheel assembly for a ground transport vehicle according to claim 1, characterized in that, The movable part has an anti-rotation part. The pressurizing device further includes a guide member for guiding the vertical movement of the movable member, the guide member contacting the anti-rotation part in a manner that prevents the movable member from rotating.

9. The wheel assembly for a ground transport vehicle according to claim 1, characterized in that, The walking wheel assembly also includes a wheel drive source that drives the walking wheels to rotate.

10. The wheel assembly for a ground transport vehicle according to claim 1, characterized in that, It also includes a second elastic member, the bottom end of which is supported by the support member and the top end of which is supported by the wheel cover, and applies a downward force to the support member through compression deformation.

11. The wheel assembly for a ground transport vehicle according to claim 10, characterized in that, At least one of the first elastic member and the second elastic member is a spring.

12. A walking mechanism characterized by comprising: Includes the walking wheel assembly for a ground transport vehicle as described in any one of claims 1 to 11.

13. The walking mechanism according to claim 12, characterized in that, It also includes casters, which are supported by the fixed part. The walking wheel assembly also includes a wheel drive source that drives the walking wheels to rotate.

14. A ground transport dolly characterized by, It includes the walking wheel assembly for a ground transport vehicle as described in any one of claims 1 to 11, or includes the walking mechanism as described in claim 12 or 13.

15. The floor transport cart of claim 14, wherein, Also includes: A first sensor detects the load weight of the ground transport vehicle; as well as The control unit receives a first signal related to the load weight of the ground transport vehicle detected by the first sensor, determines the required movement distance of the movable member based on the first signal, and drives the pressure drive source to move the movable member downward by the required movement distance.

16. The ground transport trolley according to claim 14, characterized in that, The device includes a limiting mechanism disposed on at least one of the movable member, the wheel cover, and the fixed portion, the limiting mechanism being configured to restrict the movable member from moving downward beyond a predetermined position.

17. The ground transport trolley according to claim 16, characterized in that, The limiting mechanism includes: The control unit controls the operation of the pressurization drive source; A trigger plate, wherein the trigger plate is disposed on the movable member and moves together with the movable member; and The second sensor is fixed to the wheel cover or the fixing part via a bracket and is located below the trigger plate. When the trigger plate moves to a distance less than a predetermined distance from the second sensor and triggers the second sensor, the second sensor sends a second signal to the control unit. Upon receiving the second signal, the control unit causes the pressure drive source to stop operating.

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