Stacked combined hub with notches and wheel
By using a stacked wheel hub structure with notches and adjusting the tire notch position with rotatable connection and locking components, the problem of insufficient tire grip under complex road conditions is solved, thereby improving tire grip and extending service life, and providing temporary support when the tire is damaged.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 蒋路平
- Filing Date
- 2025-05-12
- Publication Date
- 2026-04-17
AI Technical Summary
Existing vehicle tires have insufficient grip in complex road conditions such as mud, snow, desert, and stairs, and the grip is further weakened after the tires wear out, making it impossible to continue driving when the tires are punctured.
It adopts a stacked combination wheel hub structure with notches. The base wheel hub and the moving wheel hub are rotatably connected and locked. Nylon clips are used to fix the outer tire. The position of the notch can be adjusted to change the tire's grip. The moving wheel hub can be used as a temporary support to continue driving when the tire is damaged.
It improves the tire's grip under complex road conditions, extends tire life, and provides temporary support to ensure the vehicle can continue driving when the tire is damaged. It has a simple and reliable structure and is suitable for various road conditions.
Smart Images

Figure CN224130794U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of wheel hub and wheel technology, and particularly relates to a stacked composite wheel hub and wheel with a notch. Background Technology
[0002] Currently, conventional road tires have a circular outer edge. However, when the road surface is deep mud such as paddy fields, thick snow, deserts, or stairs, conventional circular tires struggle. Existing technologies often address this by adding snow chains or replacing the tire with three-, four-, or multi-claw wheels. Adding snow chains to a conventional circular tire is difficult due to the small height difference between the new chain and the tire's outer surface, making it hard to adapt to the aforementioned road conditions. While replacing the tires with multi-claw wheels at both ends of the axle can achieve actions like climbing stairs, the removed multi-claw wheels take up space and require separate storage when the circular tire is needed, causing inconvenience. Furthermore, after years of use, the original tire treads of conventional vehicle tires wear down significantly, greatly reducing their grip and affecting the vehicle's normal use. This invention offers a possible solution to maximize tire grip. In current vehicle tire technology, if a tire is punctured by an obstacle, the entire tire collapses, rendering the vehicle immobile. This deficiency is expected to be improved in the design of this utility model. Utility Model Content
[0003] The purpose of this utility model is to propose a transformation of the structure of the outer circumference of a traditional circular vehicle wheel hub. Using conventional machining methods such as stamping, stretching, and welding, this utility model conceives and produces a vehicle wheel hub composed of metal circular plates with fan-shaped notches, which are stacked, rotated, and then stacked again to form a notched metal circular plate.
[0004] The technical solution adopted in this utility model is as follows:
[0005] A stacked composite wheel hub with notches includes a base wheel hub and a moving wheel hub. The base wheel hub includes a base center disc and a base rim, and the base rim is provided with one or more fan-shaped first notches. The moving wheel hub includes a moving center disc and a moving rim, and the moving rim is provided with one or more fan-shaped second notches. The base wheel hub and the moving wheel hub are connected by a rotatable structure, and a locking component is provided between the base wheel hub and the moving wheel hub. Nylon clips are detachably provided at the bottom positions of the first and second notches. The outer circular surface of the base rim is provided with first grooves on both sides, and the outer circular surface of the moving wheel rim is provided with second grooves on both sides.
[0006] A further technical solution is that the rotatable structure includes a central shaft set in the center of the substrate center disk, an internal threaded hole in the center of the central shaft, a shaft hole seat set in the center of the moving plate center disk, the central shaft passing through the shaft hole seat and rotatably connected thereto, a central bolt being threadedly connected inside the internal threaded hole, and a compression spring being sleeved on the shaft hole seat, the compression spring being located between the moving plate center disk and the nut of the central bolt.
[0007] A further technical solution is that the rotatable structure includes a connecting hole in the center of the substrate center disk, a central cylinder coaxially fixedly connected in the connecting hole, a fixed axis plate inside the central cylinder, a connecting shaft fixed in the center of the fixed axis plate, the connecting shaft being coaxially arranged with the central cylinder, one or more movable plate hubs on the central cylinder, a cylinder seat coaxially fixedly connected in the center of the movable plate center disk, the cylinder seat being sleeved on the central cylinder and movably connected to it, the connecting shaft being threadedly connected to a positioning post, a limiting cap being provided at the end of the positioning post, a disc cover being sleeved on the positioning post, the outer diameter of the disc cover being larger than the outer diameter of the central cylinder, and the disc cover pressing against the cylinder seat.
[0008] A further technical solution is that the locking component includes at least two locking screw holes and two positioning stakes distributed circumferentially on the central disk of the substrate.
[0009] Multiple positioning tubes are arranged circumferentially on the moving plate center plate. A positioning stake is inserted into a positioning tube on each layer of the moving plate center plate. The locking bolt passes through the positioning tube from the outermost moving plate hub and is threaded into the locking screw hole.
[0010] A further technical solution is that pits are distributed at the bottom of both the substrate rim and the moving plate rim.
[0011] A further technical solution involves providing a housing on the outer side of the outermost moving plate rim.
[0012] A wheel includes a stacked composite wheel hub with a notch, wherein a first inner tube and a first outer tire are disposed within the base rim, the edges of the first outer tire are disposed in a first groove, and a nylon clip at the bottom of the first notch is clamped onto the first outer tire; a second inner tube and a second outer tire are disposed within the moving rim, the edges of the second outer tire are disposed in a second groove, and a nylon clip at the bottom of the second notch is clamped onto the second outer tire.
[0013] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:
[0014] 1. Because the base plate hub and the moving plate hub are connected by a rotatable structure, and a locking component is provided between the base plate hub and the moving plate hub, the relative position of the base plate hub and the moving plate hub in the circumferential direction can be adjusted. Because the base plate rim of the base plate hub is provided with one or more fan-shaped first notches, the first inner tube and the first outer tire mounted on the base plate hub match the base plate rim. The first outer tire is fixed to the base plate rim at the first notch using nylon clips, which can strengthen the connection between the first outer tire and the base plate rim at the first notch. Because the moving plate rim of the moving plate hub is provided with one or more fan-shaped second notches, the second inner tube and the second outer tire mounted on the moving plate hub match the moving plate rim. The second outer tire is fixed to the moving plate rim at the second notch using nylon clips, which can strengthen the connection between the second outer tire and the moving plate rim at the second notch.
[0015] 2. During normal use, adjust the corresponding positions of the base plate hub and the moving plate hub in the circumferential direction so that the first notch and the second notch are completely misaligned. In this way, the base plate hub and the moving plate hub, viewed as a whole, form a complete circular wheel. During daily use, the parts of the first outer tire outside the first notch and the parts of the second outer tire outside the second notch are frequently worn. The parts inside the first and second notches are not worn. Therefore, after these parts are worn to a certain extent, by removing the first and second outer tires and reinstalling them, the unworn parts of the first and second outer tires can be moved to positions outside the first and second notches. This can restore some of the tire's grip and extend its service life. Moreover, in the event of a puncture, if the first inner tube and the first outer tire are damaged, the moving plate hub, the second inner tube, and the second outer tire can provide temporary support, allowing continued driving.
[0016] 3. If increased grip is required, adjust the relative positions of the base plate hub and the moving plate hub in the circumferential direction so that the first notch and the second notch are aligned or partially misaligned. Due to the existence of the first and second notches, there will be a drop when the wheel rotates to the first and second notches. Combined with the corners on the outer sides of the first and second notches, a new concave-convex state is formed on the outer edge of the tire to improve grip and thus improve vehicle passability. That is, the different misalignment angles between the first and second notches result in different grip capabilities.
[0017] 4. This utility model has a novel and simple structure, effective and reliable performance, and convenient state transformation. When combined with tires, this wheel hub can adapt to various road conditions, improving vehicle passability.
[0018] 5. The relative positions of the base plate hub and the moving plate hub can be manually rotated and changed according to road conditions. After the change and locking, the different concave and convex tire surfaces composed of opposing protrusions and notches mounted on the hub will be altered. The different force angles and postures of these tire surfaces in actual contact with the ground will change the grip of the tires on such hubs, effectively improving the vehicle's passability under different road conditions. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the substrate hub described in Embodiment 1 of this utility model;
[0020] Figure 2 This is a schematic diagram of the substrate hub with a first outer tire as described in Embodiment 1 of this utility model;
[0021] Figure 3 This is a cross-sectional structural diagram of the substrate hub described in Embodiment 1 of this utility model;
[0022] Figure 4 This is a schematic diagram of the moving plate hub described in Embodiment 1 of this utility model;
[0023] Figure 5 This is a schematic cross-sectional view of the moving plate wheel hub with a second outer tire as described in Embodiment 1 of this utility model;
[0024] Figure 6 This is a cross-sectional structural schematic diagram of the moving plate hub described in Embodiment 1 of this utility model;
[0025] Figure 7 This is a schematic cross-sectional view of the moving plate wheel hub with a second outer tire as described in Embodiment 1 of this utility model;
[0026] Figure 8 This is a schematic diagram of the structure after the substrate hub and the moving plate hub are connected according to Embodiment 1 of this utility model;
[0027] Figure 9 This is a schematic cross-sectional view of the substrate hub and the moving plate hub after they are connected, as described in Embodiment 1 of this utility model.
[0028] Figure 10 This is a schematic diagram of the connection structure of the outer shell described in Embodiment 1 of this utility model;
[0029] Figure 11 This is a side view of the structure after the substrate hub and the moving plate hub are connected, as described in Embodiment 1 of this utility model;
[0030] Figure 12 This is a schematic diagram of the substrate hub corresponding to Embodiment 2 of this utility model;
[0031] Figure 13This is a cross-sectional structural schematic diagram of the substrate hub corresponding to Embodiment 2 of this utility model;
[0032] Figure 14 This is a cross-sectional structural schematic diagram of the moving plate hub corresponding to Embodiment 2 of this utility model;
[0033] Figure 15 This is a schematic diagram of the structure after the substrate hub and the moving plate hub are connected according to Embodiment 2 of this utility model;
[0034] Figure 16 This is a schematic cross-sectional view of the substrate hub and the moving plate hub after they are connected, corresponding to Embodiment 2 of this utility model.
[0035] Figure 17 This is a schematic diagram of the structure of the connection between the first outer tire, the first inner tire and the base plate hub of this utility model;
[0036] Figure 18 This is a schematic diagram of the connection structure of the nylon clip described in this utility model;
[0037] Figure 19 This is a schematic diagram of the structure of the connection between the second outer tire, the second inner tire and the moving plate hub of this utility model. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.
[0039] like Figures 1-19 As shown.
[0040] Example 1: A stacked composite wheel hub with notches, comprising a base plate hub 1 and a moving plate hub 2. The base plate hub 1 includes a base plate center disk 3 and a base plate rim 4. The base plate rim 4 is located around the base plate center disk 3, meaning that everything inside the base plate rim 4 belongs to the structure of the base plate center disk 3. The base plate rim 4 is provided with one or more fan-shaped first notches 5. The moving plate hub 2 includes a moving plate center disk 6 and a moving plate rim 7. The moving plate rim 7 is located around the moving plate center disk 6, meaning that everything inside the moving plate rim 2 belongs to the structure of the base plate center disk 3. All plates within 7 belong to the structure of the moving plate center disk 6. The moving plate rim 7 is provided with one or more fan-shaped second notches 8. The base plate hub 1 and the moving plate hub 2 are connected by a rotatable structure, and a locking component is provided between the base plate hub 1 and the moving plate hub 2. Nylon clips 9 are detachably provided at the bottom positions of the first notch 5 and the second notch 8. The outer circular surface of the base plate rim 4 is provided with first grooves 10 on both sides, and the outer circular surface of the moving plate rim 7 is provided with second grooves 11 on both sides.
[0041] A wheel includes a stacked composite hub with a notch. A first inner tube 30 and a first outer tire 31 are disposed in the base rim 4. The edges on both sides of the first outer tire 31 are disposed in a first groove 10. A nylon clip 9 at the bottom of the first notch 5 is clamped on the first outer tire 31. A second inner tube 32 and a second outer tire 33 are disposed in the moving rim 7. The edges on both sides of the second outer tire 33 are disposed in a second groove 11. A nylon clip 9 at the bottom of the second notch 8 is clamped on the second outer tire. One end of the nylon clip 9 is engaged with the base plate rim 4. Specifically, a fixing hole 35 is opened on the base plate rim 4, and one end of the nylon clip 9 passes through the fixing hole 35. A limiting head 36 is provided at the end of the nylon clip 9. A through hole is opened at the other end of the nylon clip 9, and a fixing threaded hole is opened on the base plate rim 4. The clip fixing bolt 37 passes through the through hole and is threadedly connected to the fixing threaded hole. Similarly, a fixing hole 35 is opened on the moving plate rim 7, and one end of the nylon clip 9 passes through the fixing hole 35. A limiting head 36 is provided at the end of the nylon clip 9, and a through hole is opened at the other end of the nylon clip 9. A fixing threaded hole is opened on the moving plate rim 7, and the clip fixing bolt 37 passes through the through hole and is threadedly connected to the fixing threaded hole. Nylon has a tensile strength close to that of metal and wear resistance 10 times that of cotton and 20 times that of wool. It is suitable for manufacturing mechanical parts such as gears and bearings. Therefore, nylon material with moderate hardness is selected, which is relatively suitable for this utility model.
[0042] A fixing threaded hole is provided on the base plate rim 4 for the clamp fixing bolt 37, and a fixing threaded hole is also provided on the moving plate rim 7. In use, a bolt hole 39 for connecting the wheel axle 38 is provided on the base plate center plate 3 of the base plate hub 1, and the base plate hub 1 is connected to the wheel axle 38 by the wheel bolt 40.
[0043] The first inner tube 30 is fitted onto the base plate rim 4, and then the first outer tire 31 is fitted onto the base plate rim 4. The first inner tube 30 is restricted to the base plate rim 4 by the first outer tire 31. The edge of the first outer tire 31 matches the first notch 5. The materials of the first inner tube 30 and the first outer tire 31 are the same as those of existing inner tubes and outer tires. The second inner tube 32 is fitted onto the moving plate rim 7, and then the second outer tire 33 is fitted onto the moving plate rim 7. The second inner tube 32 is restricted to the moving plate rim 7 by the second outer tire 33. The edge of the second outer tire 33 matches the second notch 8. The materials of the second inner tube 32 and the second outer tire 33 are the same as those of existing inner tubes and outer tires.
[0044] During normal use, the corresponding positions of the base plate hub 1 and the moving plate hub 2 in the circumferential direction are adjusted so that the first notch 5 and the second notch 8 are completely misaligned. In this way, the base plate hub 1 and the moving plate hub 2, viewed as a whole, form a complete circular wheel. During daily use, the parts of the first outer tire 31 outside the first notch 5 and the parts of the second outer tire 33 outside the second notch 8 are frequently worn. The parts inside the first notch 5 and the second notch 8 are not worn. Therefore, after these parts are worn to a certain extent, by removing the first outer tire 31 and the second outer tire 33 and reinstalling them, the unworn parts of the first outer tire 31 and the second outer tire 33 are partially or completely moved to the position outside the first notch 5 and the second notch 8. This can restore some of the tire's grip.
[0045] In summary, there are two ways to change the grip of a wheel by altering the combination of wheel hubs: first, by changing the angle between adjacent notches, causing the outer geometry of the rim to change its concave-convex state; second, by utilizing the flexibility of the tire to move the relative positions of the worn tire at various notches on the wheel hub to restore some of the original grip of the wheel as a whole.
[0046] The substrate hub 1 is formed by stamping two notched metal discs, each notched metal disc being half of the substrate hub 1. The two stamped metal discs are then welded back to back with their notches aligned. The cavity in the center of the substrate center disc 3 is used to weld and mount the center shaft 13. The locking screw hole 25 and the positioning post 26 on the substrate hub 1 are also welded together with the substrate. The moving plate hub 2 is formed in the same way. The cavity in the center of the moving plate center disc 6 of the moving plate hub 2 is welded together with the shaft hole seat 14. The positioning tube 27 on the moving plate hub 2 is also welded together with the moving plate hub 2.
[0047] In the event of a puncture, if the first inner tube 30 and the first outer tire 31 are damaged, the moving plate hub 2, the second inner tube 32 and the second outer tire 33 can provide temporary support to allow continued driving. Similarly, if the second inner tube 32 and the second outer tire 33 are damaged, the base plate hub 1, the first inner tube 30 and the first outer tire 31 can provide temporary support to allow continued driving.
[0048] If increased grip is required, adjust the corresponding positions of the base plate hub 1 and the moving plate hub 2 in the circumferential direction so that the first notch 5 and the second notch 8 are aligned or partially misaligned. Due to the presence of the first notch 5 and the second notch 8, there will be a drop when the wheel rotates to the first notch 5 and the second notch 8. Combined with the corners on the outside of the first notch 5 and the second notch 8, there is better grip, which is beneficial to improving the vehicle's passability. The grip is different depending on the misalignment angle of the first notch 5 and the second notch 8.
[0049] The rotatable structure includes a central shaft 12 located in the center of the substrate center disk 3, an internal threaded hole 13 located in the center of the central shaft 12, a shaft hole seat 14 located in the center of the moving plate center disk 6, the central shaft 12 passing through the shaft hole seat 14 and rotatably connected thereto, a central bolt 15 being threadedly connected inside the internal threaded hole 13, and a compression spring 16 being sleeved on the shaft hole seat 14, the compression spring 16 being located between the moving plate center disk 6 and the nut of the central bolt 15. The moving plate hub 2 is fixed to the central shaft 12 by the central bolt 15 and the compression spring 16. The number of moving plate hubs 2 can be increased by extending the length of the central shaft 12. The moving plate hub 2 can rotate around the central shaft 12 of the base plate hub 1. After the moving plate hub 2 and the base plate hub 1 are stacked, the step angle of concentric rotation can be selected within an integer multiple of 22.5 degrees in the 360-degree range in this example. That is, the grip capability of the tire on the outer end face of this vehicle combination wheel hub composed of multiple stacked notched metal discs can vary due to the different included angles and positions between the two types of wheel hubs or between the convex and notched parts of the multiple moving plate hubs 2. This allows for more variations in the grip capability of the tire on the outer end face of the vehicle combination wheel hub composed of stacked notched wheel hubs.
[0050] The locking assembly includes at least two locking screw holes 25 and positioning posts 26 arranged circumferentially on the substrate center disk 3, and multiple positioning tubes 27 arranged circumferentially on the moving plate center disk 6. A positioning post 26 is inserted into a positioning tube 27 on each moving plate center disk (6), and a locking bolt 34 is threaded from the outermost end and through a positioning tube 27 of each layer to the inside of the locking screw hole (25).
[0051] In other words, when installing the substrate hub 1 and the moving hub 2, when the moving hub 2 is fitted onto the central shaft 12, the positioning pin 26 on the substrate center plate 3 is aligned with the corresponding positioning tube 27 on the moving center plate 6, and the positioning pin 26 is inserted into the corresponding positioning tube 27. A locking bolt 34 is inserted into the positioning tube 27 of the outermost moving hub 2 corresponding to the locking screw hole 25, and the locking bolt 34 is connected to the locking screw hole 25 by threads.
[0052] Both the base rim 4 and the moving rim 7 have recesses 28 distributed on their inner bottom. These recesses 28 are designed to dampen the sliding of the first inner tube 30 within the hub of the base rim 4, and similarly, to dampen the sliding of the second inner tube 32 within the hub of the moving rim 7. At this point, on the outermost moving rim hub 2, the compression spring 16 is fitted into the axle hole seat 14, the center bolt 15 is inserted into the internal threaded hole 13, and after tightening the center bolt 15, the outer shell 29 is installed. The compression spring 16 acts as a spring washer to prevent the center bolt 15 from loosening.
[0053] Example 2: Unlike Example 1, the rotatable structure has a connecting hole 17 in the middle of the substrate center disk 3. A central cylinder 18 is coaxially fixedly connected inside the connecting hole 17. A fixed axis plate 19 is set inside the central cylinder 18. A connecting shaft 20 is fixed in the middle of the fixed axis plate 19. The connecting shaft 20 is coaxially set with the central cylinder 18. These structures are all fixed together by welding. One or more moving plate hubs 2 are set on the central cylinder 18. In this example, a cylinder seat 21 is coaxially welded and fixedly connected to the middle of the moving plate center disk 6. The cylinder seat 21 is sleeved on the central cylinder 18 and movably connected to it. The connecting shaft 20 is threadedly connected to the positioning post 22. A limit cap 23 is set at the end of the positioning post 22. A disc cover 24 is sleeved on the positioning post 22. The outer diameter of the disc cover 24 is larger than the outer diameter of the central cylinder 18. The disc cover 24 presses against the cylinder seat 21.
[0054] After the movable plate hub 2 is mounted on the central cylinder 18, it restricts the axial position of the movable plate hub 2 with the disc cover 24. The number of movable plate hubs 2 can be increased by extending the length of the central cylinder 18.
[0055] The above are merely preferred embodiments of this utility model.
Claims
1. A split stack hub characterized by, The device includes a substrate hub (1) and a moving plate hub (2). The substrate hub (1) includes a substrate center disk (3) and a substrate rim (4). The substrate rim (4) is provided with one or more fan-shaped first notches (5). The moving plate hub (2) includes a moving plate center disk (6) and a moving plate rim (7). The moving plate rim (7) is provided with one or more fan-shaped second notches (8). The substrate hub (1) and the moving plate hub (2) are connected by a rotatable structure. A locking component is provided between the substrate hub (1) and the moving plate hub (2). Nylon clips (9) are detachably provided at the bottom of the first notch (5) and the second notch (8). A first groove (10) is provided on both sides of the outer circular surface of the substrate rim (4). A second groove (11) is provided on both sides of the outer circular surface of the moving plate rim (7).
2. A split spoke wheel hub according to claim 1 wherein, The rotatable structure includes a central shaft (12) in the center of the substrate center disk (3), an internal threaded hole (13) in the center of the central shaft (12), a shaft hole seat (14) in the center of the moving plate center disk (6), the central shaft (12) passing through the shaft hole seat (14) and rotatably connected to it, a central bolt (15) is threaded inside the internal threaded hole (13), and a compression spring (16) is sleeved on the shaft hole seat (14), the compression spring (16) being located between the moving plate center disk (6) and the nut of the central bolt (15).
3. A split spoke hub according to claim 1 wherein, The rotatable structure includes a connecting hole (17) in the middle of the substrate center disk (3), a central cylinder (18) coaxially fixedly connected in the connecting hole (17), a fixed axis plate (19) inside the central cylinder (18), a connecting shaft (20) fixed in the middle of the fixed axis plate (19), the connecting shaft (20) and the central cylinder (18) being coaxially arranged, and one or more moving plate hubs (2) being provided on the central cylinder (18), a cylinder seat (21) coaxially fixedly connected in the middle of the moving plate center disk (6), the cylinder seat (21) being sleeved on the central cylinder (18) and movably connected to it, the connecting shaft (20) being threadedly connected to a positioning post (22), a limiting cap (23) being provided at the end of the positioning post (22), a disc cover (24) being sleeved on the positioning post (22), the outer diameter of the disc cover (24) being larger than the outer diameter of the central cylinder (18), and the disc cover (24) pressing against the cylinder seat (21).
4. A split rim hub according to claim 2 or 3, wherein, The locking assembly includes at least two locking screw holes (25) and two positioning posts (26) distributed circumferentially on the substrate center disk (3). Multiple positioning tubes (27) are arranged circumferentially on the moving plate center plate (6). A positioning stake (26) is inserted into a positioning tube (27) on each layer of moving plate center plate (6). The locking bolt (34) passes through the positioning tube (27) from the outermost moving plate hub (2) and is threaded into the locking screw hole (25).
5. A split spoke hub according to claim 4 wherein, The bottom of both the substrate rim (4) and the moving plate rim (7) are provided with recesses (28).
6. A split spoke hub according to claim 4 wherein, The outermost moving plate rim (7) is provided with a housing (29).
7. A vehicle wheel, characterised in that The present invention includes a stacked composite wheel hub with a notch as described in claim 4, wherein a first inner tube (30) and a first outer tire (31) are provided in the base rim (4), the edges on both sides of the first outer tire (31) are provided in the first groove (10), and a nylon clip (9) at the bottom of the first notch (5) is clamped on the first outer tire (31). A second inner tube (32) and a second outer tire (33) are provided in the moving rim (7), the edges on both sides of the second outer tire (33) are provided in the second groove (11), and a nylon clip (9) at the bottom of the second notch (8) is clamped on the second outer tire (33).