Chainless sprocketed bicycle

Abstract

The application discloses a chainless large-tooth-ratio two-wheeled vehicle and relates to the technical field of two-wheeled vehicles. The chainless large-tooth-ratio two-wheeled vehicle comprises a vehicle frame, a front wheel set and a rear wheel set arranged at two ends of the vehicle frame, two crank pedal assemblies arranged at two axial ends of the rear wheel set and rotating along the axis of the rear wheel set, and a transmission gear set arranged at one axial end of the rear wheel set. The transmission gear set is arranged between the rear wheel set and one crank and pedal, and the pedal is in transmission connection with the rear wheel set through the transmission gear set. The technical scheme provided by the application aims to solve the technical problem that the pedal frequency of the rear wheel direct-drive bicycle is high and the riding experience is poor in the prior art.

Description

Technical Field

[0001] This invention relates to the field of two-wheeled vehicle technology, and in particular to a chainless two-wheeled vehicle with a large gear ratio. Background Technology

[0002] Bicycles generally use chains as the power transmission medium from the pedals to the rear wheel. Chain drives rely on the coordinated work of multiple exposed parts, which are prone to contamination and wear under long-term use or in complex environments, leading to failures such as detachment and breakage, resulting in transmission interruption, frequent maintenance, and insufficient reliability.

[0003] To address the aforementioned issues, a rear-wheel direct-drive bicycle has emerged in the prior art. In this design, the pedals and cranks are directly mounted on both ends of the hub, directly driving the rear wheel. While this direct-drive system eliminates the chain drive structure and the risk of chain damage, it requires modifications to the hubs, necessitating the addition of components such as bushings or ball bearings to the bearings, resulting in a complex structure and lower reliability and convenience. However, direct-drive of the rear wheel via the crank and pedals has certain drawbacks; for every revolution of the crank, the rear wheel only rotates once, failing to achieve gear ratio conversion. This pedaling method, lacking a transmission mechanism, leads to a high cadence and a poor riding experience. Summary of the Invention

[0004] The main objective of this invention is to propose a chainless two-wheeled vehicle with a large gear ratio, aiming to solve the technical problem of low transmission efficiency in existing rear-wheel direct-drive bicycles, which leads to high cadence and poor riding experience.

[0005] To achieve the above objectives, the present invention proposes a chainless, high-ratio two-wheeled vehicle, comprising: Frame; A front wheel assembly and a rear wheel assembly, wherein the front wheel assembly and the rear wheel assembly are respectively disposed at both ends of the frame; Two crank-pedal assemblies are respectively rotatably mounted at both ends of the rear wheel assembly; It also includes a transmission gear set, which is disposed on the rear wheel assembly and is connected in a transmission manner between the rear wheel assembly and at least one of the crank pedal assemblies, wherein the crank pedal assembly drives the rear wheel assembly to rotate through the transmission gear set.

[0006] In one embodiment, the transmission gear set includes: Crankset, one of the crank pedal assemblies is axially connected to one end of the crankset; A gear transmission mechanism, wherein the gear transmission mechanism is disposed within the gear ring; The gear transmission mechanism is connected to the rear wheel assembly and to the chainring. The center of the toothed disc has an installation space, and the gear transmission mechanism is located within the installation space.

[0007] In one embodiment, a chainring holder is provided on one side of the chainring, and the chainring holder partially covers the center of the chainring axis; one end of the chainring holder is fixedly connected to a crank pedal assembly via a crank.

[0008] In one embodiment, the gear transmission mechanism includes: A flywheel, which is connected to the rear wheel assembly in a drivetrain; and A planetary gear set, wherein the planetary gear set is respectively connected to the flywheel and the chainring; The flywheel and the chainring are coaxially arranged, and the flywheel, the planetary gear set, and the chainring are coplanar in a vertical plane; the teeth of the chainring are arranged within the mounting space.

[0009] In one embodiment, the planetary gear set includes: Planetary gears, which mesh with the teeth of the toothed sprocket; and An idler gear meshes with both the planetary gear and the flywheel.

[0010] In one embodiment, the planetary gear set further includes a planetary gear carrier, which is connected to the planetary gears and the idler gear via bearings to support the meshing transmission of the planetary gear set; the planetary gear carrier is disposed on the side of the rear gear set facing the planetary gear set via bearings.

[0011] In one embodiment, the rear wheel assembly includes: The rear wheel has a hub at its center; The planetary gear carrier is mounted on one end of the hub via a bearing, and the flywheel drive is connected to one end of the hub.

[0012] In one embodiment, the rear wheel assembly further includes a bottom bracket, the hub has a cavity at its center, the bottom bracket passes through the cavity, and the bottom bracket is connected to the hub via a bearing; one end of the bottom bracket is fixedly connected via a crank pedal assembly; the other end of the bottom bracket is fixedly connected to the chainring.

[0013] In one embodiment, the frame includes: beam; The front fork and the rear fork are respectively disposed at both ends of the crossbeam, and the front fork is provided with a handle.

[0014] In one embodiment, a seat is provided at one end of the crossbeam near the rear fork, and the seat is positioned above the rear wheel assembly.

[0015] The technical solution of this invention involves setting a front wheel assembly and a rear wheel assembly at both ends of the frame, and installing cranks and pedals at both axial ends of the rear wheel assembly, allowing the two cranks to rotate along the rear wheel assembly axis. Simultaneously, a transmission gear set is positioned at one axial end of the rear wheel assembly, between the rear wheel assembly and one side of the crank and pedal, enabling the pedal to be connected to the rear wheel assembly via the transmission gear set. Therefore, the rotational power input by the pedal is not directly transmitted to the rear wheel assembly, but rather through intermediate transmission via the transmission gear set before being output to the rear wheel assembly. This improves the high cadence problem caused by the low gear ratio (1:1 rotation) between the crank and rear wheel in rear-wheel direct-drive bicycles, and enhances the riding comfort and efficiency of chainless, high-gear-ratio two-wheeled bicycles.

[0016] Meanwhile, this invention eliminates the need for a traditional chain as the power transmission medium from the pedals to the rear wheel, reducing the risk of contamination, wear, detachment, and breakage caused by exposed chains, lowering the frequency of transmission system maintenance, and improving the overall transmission reliability. Since the transmission gears are concentrated at one axial end of the rear wheel assembly, located between the rear wheel assembly and one side crank and pedal, the power transmission structure is centrally located near the rear wheel assembly. This eliminates the need to reserve transmission space extending along the frame's longitudinal direction for chain drive, simplifying the frame structure, improving vehicle compactness, and making it suitable for the structural layout requirements of folding or portable bicycles. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the chainless, high-ratio two-wheeled vehicle provided by the present invention; Figure 2 A schematic diagram of the rear wheel assembly of the chainless, high-ratio two-wheeled vehicle provided by the present invention; Figure 3 A cross-sectional view of the rear wheel assembly of the chainless, high-ratio two-wheeled vehicle provided by the present invention; Figure 4 An exploded view of the rear wheel assembly of a chainless, high-ratio two-wheeled vehicle provided by the present invention. Figure 5 A schematic diagram of the transmission gear assembly of the chainless, high-ratio two-wheeled vehicle provided by the present invention; Figure 6 An exploded view of the transmission gear set of the chainless, high-ratio two-wheeled vehicle provided by the present invention.

[0019] Explanation of icon numbers: 1. Frame; 2. Front wheel assembly; 3. Rear wheel assembly; 4. Crankset and pedal assembly; 5. Drivetrain; 6. Chainring; 7. Chainring carrier; 8. Freewheel; 9. Idler gear; 10. Planetary gears; 11. Planetary gear carrier; 12. Rear wheel; 13. Hub; 14. Bottom bracket; 15. Crossbeam; 16. Front fork; 17. Rear fork; 18. Seat; 19. Wheel collar; 20. Bearing.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] This invention proposes a chainless two-wheeled vehicle with a large gear ratio.

[0025] Please see Figures 1 to 6 In one embodiment of the present invention, the chainless high-ratio two-wheeled vehicle includes: a transmission gear set 5, which is disposed on the rear wheel set 3 and is connected in a transmission manner between the rear wheel set 3 and at least one crank pedal assembly 4, wherein the crank pedal assembly 4 drives the rear wheel set 3 to rotate through the transmission gear set 5.

[0026] Specifically, the chainless, high-ratio two-wheeled bicycle in this embodiment eliminates the chain, chain tensioner, and centrally mounted frame structure of traditional bicycles. The frame 1 has a front fork 16 at the front and a rear fork 17 at the rear. The front wheel assembly 2 is rotatably mounted on the lower end of the front fork 16, and the rear fork 17 has a collar 19 at its end. The rear wheel assembly 3 is rotatably mounted within the collar 19 via a ball bearing 20. The collar 19 eliminates the instability associated with welding or using curved screws. The crank-pedal assembly 4 includes two cranks located axially on the left and right sides of the rear wheel assembly 3, and pedals respectively mounted on the ends of the cranks. The two crank-pedal assemblies 4 do not directly form a 1:1 fixed rigid drive with the hub 13 of the rear wheel assembly 3, but instead concentrate the power input at a transmission gear set 5 located at one axial end of the rear wheel assembly 3.

[0027] The transmission gear set 5 is arranged coaxially or parallel to the rotation axis of the rear wheel set 3, and is compactly integrated into the axial side of the rear wheel set 3. When the rider pedals the crank-pedal assembly 4 in a circular motion around the axis of the rear wheel set 3, the torque is first transmitted to the power input component of the transmission gear set 5. The transmission gear set 5 converts the input speed and torque through the meshing ratio of the internal gear system, forming an intermediate transmission stage. Its output end is then connected to the drive input part of the rear wheel set 3, thereby driving the rear wheel set 3 to rotate around its axis and propelling the entire vehicle forward. By eliminating the chain drive link that runs through the front and rear of the frame, the power transmission path of the entire vehicle is highly compressed within the space of the rear wheel set 3 and its axial end, completely eliminating the structural hazards of chain detachment, breakage, oil contamination, and interference with frame folding.

[0028] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the transmission gear set 5 includes: a chainring 6, a crank pedal assembly 4 and the chainring 6 being axially disposed away from the rear wheel assembly 3; a gear transmission mechanism disposed within the chainring 6; wherein the gear transmission mechanism is pulsatorically connected to the rear wheel assembly 3 and pulsatorically connected to the chainring 6; the chainring 6 has an installation space at its center, and the gear transmission mechanism is disposed within the installation space.

[0029] Specifically, the chainring 6 has a large-diameter annular internal gear disc structure, with a disc-shaped mounting space that is axially continuous or has a single-sided opening in its center. The chainring 6 is located on the axially outer side of the rear wheel assembly 3, while the pedal in the crank pedal assembly 4 located on the same side is further arranged on the side of the chainring 6 that is axially away from the rear wheel assembly 3.

[0030] The two fork arms of the rear fork 17 are located at both circumferential ends of the rear wheel assembly 3. The two ends of the rear wheel assembly 3 are connected to the collars 19 at the bottom of the fork arms of the rear fork 17 via bearings 20. The chainring 6 is located at one end of the rear fork 17. The hub 13 of the rear wheel assembly 3 passes through the bearing 20 and is connected to the gear transmission mechanism. The chainring 6 and the gear transmission mechanism within the chainring 6 are located on both axial sides of the rear fork 17, which ensures that the rear fork 17 does not interfere with or obstruct the gear transmission mechanism when the chainring 6 drives it.

[0031] The gear transmission mechanism is housed within the mounting space at the center of the chainring 6. The inner or outer wall of the chainring 6 forms power input teeth that mesh with the input gear of the gear transmission mechanism. The output end of the gear transmission mechanism passes through the axial inner side of the mounting space and forms a transmission connection with the rear wheel assembly 3. The high gear ratio power output of the gear transmission mechanism solves the 1:1 transmission ratio problem inherent in traditional rear-wheel direct-drive two-wheeled vehicles. It achieves a transmission ratio of 1:1.5 to 1:3 or higher within a limited space, allowing the rear wheel assembly 3 to rotate multiple times for every revolution of the crank. This solves the core problem of excessively high cadence and poor riding efficiency caused by the low transmission ratio of rear-wheel direct-drive systems.

[0032] This nested structure allows the chainring 6 to not only serve as a torque input component, but also as a protective cover for the gear transmission mechanism, enclosing the internal meshing gears within the installation space, reducing the axial length of the gear transmission system in the rear wheel set 3, and improving the axial compactness of the overall vehicle structure.

[0033] Please see Figure 2 and Figure 3 In one embodiment of the present invention, a crank holder 7 is provided on one side of the crank 6, and the crank holder 7 partially covers the axis of the crank 6; one end of the crank holder 7 is fixedly connected to a foot pedal via a crank.

[0034] Specifically, the crankset 7, as a transition and support component for power transmission, can be designed as a multi-spoke star-shaped frame or a ring-shaped support arm plate structure. The crankset 7 is arranged on the axial outer side of the crankset 6, with its central part covering and fixed to the extension line of the crankset 6's axis. The outer support arm is fixedly connected to the ring-shaped body of the crankset 6 by bolt connection, spline fitting, welding, or integral molding, thereby constraining the crankset 7 and the crankset 6 into a rigid coaxial rotating body.

[0035] The axle extension of the chainring 7 is fixedly connected to the pedal located on that side via a high-strength connecting crank. One end of the crank is rotatably connected to the pedal axle. When the rider pedals, the force is applied directly to the chainring 7 via the crank. The chainring 7 evenly distributes the rotational torque concentrated at the axle and transmits it to the outer main teeth of the chainring 6, improving the bending and torsional stiffness of the chainring 6 under alternating pedaling loads and preventing axial runout or eccentric wear of the chainring 6.

[0036] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the gear transmission mechanism includes: a flywheel 8, which is connected to the rear wheel assembly 3; and a planetary gear set, which is connected to the flywheel 8 and the chainring 6 respectively; wherein the flywheel 8 and the chainring 6 are coaxially arranged, and the flywheel 8, the planetary gear set and the chainring 6 are coplanarly arranged in a vertical plane; the teeth of the chainring 6 are arranged within the mounting space.

[0037] Specifically, the gear transmission mechanism employs a coaxial, coplanar hybrid gear system combining in-plane and external meshing. An inner ring gear is machined into the inner wall of the mounting space of the chainring 6, making the chainring 6 itself the internal gear ring of this gear system, equivalent to the internal gear ring component in a planetary gear system. The flywheel 8, as the power output component, has an external gear machined into its outer circumference. The center of the flywheel 8 is located on the rear wheel axle and is connected to the rear wheel assembly 3 for transmission. The flywheel 8 and the chainring 6 are arranged coaxially.

[0038] The planetary gear set is positioned within the annular space between the internal ring gear of the chainring 6 and the external ring gear of the freewheel 8. Spatially, the pitch circle planes of the internal ring gear of the chainring 6, the pitch circle planes of each gear in the planetary gear set, and the pitch circle plane of the external ring gear of the freewheel 8 all coincide in the same vertical plane perpendicular to the rear wheel axis. This coplanar layout allows the rotational motion input from the chainring 6 to be directly transmitted inward to the planetary gear set through the internal gear mounted on the inner wall of the space. The planetary gear set further transmits the motion to the innermost freewheel 8 within the same vertical plane.

[0039] This design avoids the traditional axially extended transmission system. The transmission components are arranged along the radial space of the chainring, saving axial length and optimizing the space occupied in the rear axle area of ​​the bicycle.

[0040] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the planetary gear set includes: a planetary gear 10, which meshes with the teeth of the sprocket 6; and an idler gear 9, which meshes with the planetary gear 10 and the flywheel 8 respectively.

[0041] Specifically, the planetary gear set consists of at least one planetary gear 10 and at least one idler gear 9 forming a combined intermediate transmission gear chain. The internal gear ring on the inner wall of the mounting space of the chainring 6 meshes internally with the external teeth of the planetary gear 10. When the planetary gear 10 is driven to rotate by the chainring 6, its external teeth further mesh externally with the external teeth of the idler gear 9, and the external teeth of the idler gear 9 then mesh externally with the external teeth of the flywheel 8, thus forming a closed gear transmission chain consisting of the chainring internal gear ring, the planetary gear 10, the idler gear 9, and the flywheel 8.

[0042] The key technological role of introducing idler gear 9 lies in steering correction and gear ratio adjustment. When chainring 6 drives planetary gear 10 through internal engagement, the rotation direction of planetary gear 10 is the same as the rotation direction of chainring 6. If planetary gear 10 directly engages externally to drive cassette 8, the rotation direction of cassette 8 will be opposite to that of planetary gear 10, resulting in the incorrect movement of the rear wheel rotating in the opposite direction when pedaling forward. By intervening idler gear 9 between planetary gear 10 and cassette 8, idler gear 9 achieves an additional external engagement steering, ensuring that the final rotation direction of cassette 8 and rear wheel assembly 3 is completely consistent with the direction the rider pedals chainring 6. Simultaneously, by precisely configuring the gear ratios of chainring 6's internal teeth, planetary gear 10, idler gear 9, and cassette 8, a gear ratio of 1:1.5 to 1:3 or higher can be achieved within a limited space. This allows the rear wheel assembly 3 to rotate multiple times for every revolution of the crank, solving the core problem of excessively high cadence and poor riding efficiency caused by the low gear ratio of the rear wheel direct drive system.

[0043] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the planetary gear set further includes a planetary gear carrier 11, which is connected to the planetary gears 10 and the idler gear 9 via bearings; the planetary gear carrier 11 is disposed on the side of the rear gear set 3 facing the planetary gear set via bearings.

[0044] Specifically, the planetary gear carrier 11 is an F-type support, which includes a base collar and multiple cantilever support pins extending outward from the base collar. Each planetary gear 10 and idler gear 9 has a bearing mounting hole at its center. The planetary gear 10 and idler gear 9 are mounted on the corresponding cantilever support pins of the planetary gear carrier 11 via bearings, allowing the planetary gear 10 and idler gear 9 to rotate freely around their respective pins, while their axes are precisely positioned relative to the planetary gear carrier 11.

[0045] The base collar of the planetary gear carrier 11 is mounted on the side of the rear gear set 3 facing the planetary gear set via a bearing. This supports the planetary gears 10 and 9 while the planetary gear carrier 11, placed on the bearing 20, counteracts the rotational force of the rear gear, ensuring the planetary gear carrier 11 remains in a fixed position. The planetary gear carrier 11 fixes the center position of the planetary gears 10 and 9, ensuring they always rotate around this fixed center point. The bearing 20 under the planetary gear carrier 11 reduces the rotational resistance between the planetary gear carrier 11 and the rear gear set 3. This planetary gear carrier layout allows the planetary gears 10 and 9 to operate as an intermediate transmission gear system, reliably supporting and bearing the tangential gear meshing force transmitted between the sprocket 6 and the flywheel 8, ensuring that no center distance misalignment or tooth surface misalignment occurs under high-speed rotation and high-torque loads.

[0046] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the rear wheel assembly 3 includes: a rear wheel 12, and a hub 13 is provided at the center of the rear wheel 12; wherein, the planetary gear carrier 11 is disposed on one end of the hub 13 by means of a bearing, and the flywheel 8 is drivenly connected to one end of the hub 13.

[0047] Specifically, bearings 20 are fixedly connected to both sides of the hub 13 in the circumferential direction, and the bearings 20 are rotatably connected to the collar 19 at the lower end of the rear fork 17, so as to ensure that the rear fork 17 maintains its stable support when the rear 12 wheels rotate.

[0048] The base collar of the planetary gear carrier 11 is located at the end of the hub 13 facing the planetary gear set via a bearing 20. That is, the planetary gear carrier 11 is fixedly connected to the rear fork 17 by sharing the outer ring of the bearing 20. The bearing 20 enables the planetary gear carrier 11 to form a relative rotational support relationship with the hub 13 when supporting the planetary gears 10 and idler gears 9, reducing the frictional impact of the hub 13 on the planetary gear carrier 11 when it rotates, and ensuring the structural stability of the planetary gear carrier 11 and the rear fork 17 connected above the planetary gear carrier 11 during vehicle operation.

[0049] Please see Figure 2 and Figure 3 In one embodiment of the present invention, the rear wheel assembly 3 further includes a bottom bracket 14, the hub 13 has a cavity in the center, the bottom bracket 14 passes through the cavity, and the bottom bracket 14 is connected to the hub 13 through a bearing; one end of the bottom bracket 14 is fixedly connected to a pedal through a crank; the other end of the bottom bracket 14 is fixedly connected to the chainring 6.

[0050] Specifically, this embodiment constructs a coaxial nested rear axle transmission system. The central shaft 14 passes through the central cavity of the hub 13, and ball bearings are respectively installed at both ends of the axial direction between the outer wall of the central shaft 14 and the inner wall of the hub 13, so that the central shaft 14 and the hub 13 can rotate independently in a coaxial relative manner.

[0051] The bottom bracket 14 extends axially to the left of the hub 13 and is fixedly connected to the left pedal via the left crank; the bottom bracket 14 extends axially to the right of the hub 13 and is fixedly connected to the right chainring 6. When the rider pedals the left and right pedals, the torque of the left pedal is transmitted to the bottom bracket 14 via the left crank. The bottom bracket 14 traverses the entire rear wheel assembly 3, transmitting power to the right side and driving the chainring 6 to rotate; the torque of the right pedal directly or via the chainring bracket 7 drives the chainring 6 to rotate, thus achieving synchronous power input from the left and right pedals to the chainring 6. This structure eliminates the bottom bracket tube located in the middle of the frame of traditional bicycles, directly integrating the function of the bottom bracket 14 into the rear wheel axle, achieving a highly modular and compact chainless drive design.

[0052] Please see Figure 1 In one embodiment of the present invention, the frame 1 includes: a crossbeam 15; and a front fork 16 and a rear fork 17, wherein the front fork 16 and the rear fork 17 are respectively disposed at both ends of the crossbeam 15, and a handle is disposed on the front fork 16.

[0053] Specifically, since the chainless drive system of the present invention fully integrates the crank, bottom bracket 14, chainring 6 and gear transmission mechanism into the rear wheel assembly 3, the frame 1 no longer needs to retain the bottom tube, down tube and chainstay structure that are required in traditional bicycles. The frame 1 adopts a simple single frame or minimalist triangular frame design, mainly composed of horizontal or inclined crossbeams 15 forming the main load-bearing body.

[0054] The front end of the crossbeam 15 is equipped with a head tube, and the seat tube of the front fork 16 is rotatably inserted into the head tube. The upper end of the front fork 16 is equipped with a steering handle, and the lower end is used to install the front wheel assembly 2. The rear end of the crossbeam 15 is fixedly connected to or integrally formed with the rear fork 17. The rear fork 17 has a downwardly inclined fork-shaped structure, and its lower opening forms a rear axle mounting position for fixing the axial support components of the rear wheel assembly 3, such as the planetary gear carrier 11 and the rear axle assembly. Since the lower chainstay connecting the bottom bracket and the rear axle has been removed, the space under the frame 1 is completely freed up. This not only significantly reduces the weight of the entire vehicle and the number of parts, but also significantly shortens the front and rear wheelbase of the vehicle, greatly facilitating the vehicle's entry into elevators, buses, subways, and car trunks. It also creates excellent space conditions for the design of the bicycle's folding mechanism.

[0055] Please see Figure 1In one embodiment of the present invention, a seat 18 is provided at one end of the crossbeam 15 near the rear fork 17, and the seat 18 is disposed above the rear wheel assembly 3.

[0056] Specifically, the seat 18 is directly mounted to the joint of the crossbeam 15 near the rear fork 17 via the seat post, and in spatial projection, the main seat cushion of the seat 18 is located above the rear wheel 12.

[0057] Because the rotation center of the crank-pedal assembly 4 has been moved from the center of the bike to the axle of the rear wheel assembly 3, the input point of the rider's pedaling power has also shifted rearward. Positioning the seat 18 above the rear wheel assembly 3 conforms to the ergonomic principle of the body's center of gravity and the point of pedaling force application, allowing the rider to apply pedaling torque downwards and slightly forwards in a seated position, ensuring optimal application of force to the pedals at the rear axle. Simultaneously, the vertical alignment of the seat 18 with the rear wheel assembly 3 allows the rider's weight to be directly transmitted vertically downwards through the end of the crossbeam 15 and the rear fork 17 to the hub 13 and rear wheel 12 of the rear wheel assembly 3. This optimizes the overall stress distribution and force path of the frame 1, further enhancing the structural durability of the bike under dynamic loads.

[0058] Currently, human-powered / electric bicycles / motorcycles all use chain structures, which often lead to chain detachment / breakage. Moreover, the chain structure increases the number of bicycle / electric bicycle / motorcycle parts, resulting in a high failure rate, increased cost and weight. In particular, for folding bicycles, the chain structure further hinders the convenience of folding. The present invention has the following beneficial effects: 1. Two-wheeled vehicles, including bicycles and electric vehicles, will no longer need chain drive and can achieve the high gear ratio of traditional two-wheeled vehicles, that is, one turn of the pedal drives the wheel to rotate multiple times, resulting in higher reliability and lower maintenance costs; 2. It eliminates the need for the chainstays, downtube, and center tube found in traditional bicycles, reducing the cost of the bike; 3. The length of the two-wheeled vehicle can be shortened, making it easy to enter elevators, buses, subway cars, and car trunks, thus facilitating package delivery. 4. It greatly reduces the weight of the vehicle, resulting in less riding resistance and making riding and carrying easier.

[0059] Please see Figure 4 The left and right rear forks 17 and roller bearings 20 are installed on both sides of the hub. The gear transmission structure is on the right end of the rear fork 17, that is, the freewheel 8 is on the outside of the rear fork 17, and the rear fork 17 is placed on the bearing 20. This ensures that the rear fork 17 remains fixed while the hub 13 rotates. The installation steps are as follows: First, install the roller bearings 20 on both sides of the hub 13, and then install the rear fork 17 on the roller bearings 20; ensure that when the chainring 6 drives the freewheel 8, the rear fork 17 can avoid interference and obstruction between the chainring and the freewheel 8; add a roller bearing 20 to the collar 19. This bearing is wide enough to place the upper fork on the roller bearing. During the ride, the roller in the bearing will completely offset the rotational force of the hub, thereby ensuring that the hub 13 can always remain stationary and stably support the entire vehicle when it rotates; after adding the roller bearing 20 to the hub 13, there is no need to inject bushings or steel balls into the bearing of the hub itself, which improves reliability and convenience.

[0060] The rear fork 17 is connected to the frame 1, and a collar 19 is provided at the bottom. The collar 19 can be directly put onto the bearings 20 at both ends of the hub 13 of the rear wheel assembly 3 to securely connect the two components. Because the contact surface between the bearing 20 and the rear fork 17 is an arc-shaped surface, it replaces the traditional welding or screw fixing method of the rear fork 17 of a two-wheeled vehicle, which reduces costs and improves the fixing effect. There is no need to use screws or welding to fasten it to the roller bearing 20.

[0061] Please refer to the figure. After the rear fork 17 is installed, the freewheel 8 is installed on the hub 13 and placed on the outside of the rear fork 17. In traditional chain bicycles, the freewheel 8 is placed on the inside of the top fork. Due to the obstruction of the top fork, the chainring 6 and pedals cannot be directly integrated with the freewheel 8. Therefore, the structure of placing the freewheel 8 on the outside of the rear fork 17, combined with the collar 19 and bearing 20, can avoid interference between the chainring 6 and the freewheel 8, and the chainring 6 can drive the freewheel 8 without a chain.

[0062] Please see Figure 5 The flywheel 8 is used as the sun gear. An idler gear 9 is added above the flywheel 8. The idler gear 9 and the flywheel 8 form an external mesh. A planet gear 10 is added above the idler gear 9. The planet gear 10 and the idler gear 9 form an external mesh. The upper part of the inner ring of the chainring 6 forms an internal mesh with the planet gear 10. The whole assembly forms a planetary gear set. An F-type planetary gear carrier 11 is installed in the middle of the rear fork 17 and the freewheel 8. The idler gear 9 and the planetary gear 10 are supported by the planetary gear carrier 11, and the F-type planetary carrier 11 is placed on the bearing 20 and fixedly connected to the rear fork 17; to achieve a large gear ratio drive, that is, to ensure that the drive wheel can travel multiple revolutions when the rider pedals once without a chain. The chainring 6 is not directly connected to the freewheel 8, avoiding the chainring 6 directly driving the freewheel 8. Instead, the freewheel 8 is driven through the planetary gear 10 and idler gear 9 in the middle. By superimposing the relative motion between the gears, the rotational motion input from the chainring 6 is redistributed and transformed. Through the transmission of multiple internal and external gear meshing, coaxial output can be achieved without changing the axis position, and the gear ratio change from 1:1 to 3:1 or even higher can be realized. The structure of the planetary gear 10 ensures that the center point of the chainring 6 is always connected to the bottom bracket 14, while also allowing the rider to drive the wheel to travel multiple revolutions with one pedal revolution, making riding less strenuous. This structure, combined with the internal derailleur in the existing technology, can realize multi-gear shifting function without a chain. If the chainring 6 and the freewheel 8 are directly connected for drive, since the chainring 6 and the freewheel 8 are coaxial and rotate from the same fulcrum, it is equivalent to two fixed rotating parts moving. The gear ratio is one, that is, pressing the pedal once can only drive the wheel to rotate once. This will greatly reduce the advantages of the chainless design, thus making it impossible for the chainless high gear ratio two-wheeled vehicle to achieve true market promotion. The function of idler gear 9 is to ensure that chainring 6 and freewheel 8 can rotate in the same direction after being converted by planetary gear 10. When chainring 6 rotates in the forward direction, it drives planetary gear 10 to rotate in the forward direction under the internal meshing structure. When planetary gear 10 rotates, it drives idler gear 9 to rotate in the reverse direction by using external meshing. When idler gear 9 rotates in the reverse direction, it drives freewheel 8 to rotate in the forward direction by using external meshing with freewheel 8. Finally, a large transmission ratio is achieved, and chainring 6 and freewheel 8 can rotate in the same direction again.

[0063] Please see Figure 6 The planetary gear carrier 11 is F-shaped, with a circular collar 19 at the bottom and two protruding support arms at the top. The planetary gear carrier 11 is positioned between the rear fork 17 and the freewheel 8. The circular collar 19 at the bottom is placed on the roller bearing 20 and fixedly connected to the rear fork 17. The connection method can be screwing, welding, embedding, etc.

[0064] The planetary gear carrier 11 provides a support point for the planetary gears 10 and idler gears 9 suspended above the freewheel 8, ensuring that the planetary gears 10 and idler gears 9 are always above the freewheel 8 during rotation. The planetary gear carrier 11 is fixed in position by being placed on the fixed bearing 20 and connected to the rear fork 17. The fixed bearing 20 counteracts the rotational force of the hub 13, and the position of the planetary gear carrier 11 remains fixed when the bike and hub 13 are rotating.

[0065] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A chainless, high-ratio two-wheeled vehicle, comprising: Frame (1); A front wheel assembly (2) and a rear wheel assembly (3) are respectively disposed at both ends of the frame (1); Two crank pedal assemblies (4) are rotatably mounted on both ends of the rear wheel assembly (3); Its characteristic is that it further includes: A transmission gear set (5) is disposed on the rear wheel assembly (3) and is connected in transmission between the rear wheel assembly (3) and at least one crank pedal assembly (4). The crank pedal assembly (4) drives the rear wheel assembly (3) to rotate through the transmission gear set (5).

2. The chainless, high-ratio two-wheeled vehicle as described in claim 1, characterized in that, The transmission gear set (5) includes: A crank-pedal assembly (4) is disposed at one end of the crank chainring (6); A gear transmission mechanism is disposed within the toothed disc (6); The gear transmission mechanism is connected to the rear wheel assembly (3) and to the chainring (6); the chainring (6) has an installation space in the center and the gear transmission mechanism is located in the installation space.

3. The chainless, high-ratio two-wheeled vehicle as described in claim 2, characterized in that, A chainring holder (7) is provided on one side of the chainring (6), and the chainring holder (7) partially covers the axis of the chainring (6); one end of the chainring holder (7) is fixedly connected to the crank pedal assembly (4).

4. The chainless, high-ratio two-wheeled vehicle as described in claim 2, characterized in that, The gear transmission mechanism includes: Flywheel (8), which is connected to the rear wheel assembly (3) via a transmission; and Planetary gear set, wherein the planetary gear set is respectively connected to the flywheel (8) and the chainring (6); The flywheel (8) and the chainring (6) are coaxially arranged, and the flywheel (8), the planetary gear set and the chainring (6) are coplanar on the vertical plane; the teeth of the chainring (6) are arranged in the mounting space.

5. The chainless, high-ratio two-wheeled vehicle as described in claim 4, characterized in that, The planetary gear set also includes a planetary gear carrier (11), and the planetary gear set is mounted on one side of the planetary gear carrier (11) via a bearing to support the meshing transmission of the planetary gear set; the planetary gear carrier (11) is mounted on the side of the rear gear set (3) facing the planetary gear set via a bearing.

6. The chainless, high-ratio two-wheeled vehicle as described in claim 5, characterized in that, The planetary gear set includes: Planetary gear (10), which meshes internally with the teeth of the toothed disc (6); and An idler gear (9) meshes with the planetary gear (10) and the flywheel (8) respectively; The planetary gear carrier (11) is connected to the planetary gear (10) and the idler gear (9) via bearings.

7. The chainless, high-ratio two-wheeled vehicle as described in claim 6, characterized in that, The rear wheel assembly (3) includes: The rear wheel (12) has a hub (13) at its center. The planetary gear carrier (11) is mounted on one end of the hub (13) via a bearing, and the flywheel (8) is connected to one end of the hub (13) via a drive.

8. The chainless, high-ratio two-wheeled vehicle as described in claim 7, characterized in that, The rear wheel assembly (3) also includes a bottom bracket (14). The hub (13) has a cavity in the center. The bottom bracket (14) passes through the cavity. The bottom bracket (14) is connected to the hub (13) through a bearing. One end of the bottom bracket (14) is fixedly connected to a crank pedal assembly (4). The other end of the bottom bracket (14) is fixedly connected to the chainring (6).

9. The chainless, high-ratio two-wheeled vehicle as described in claim 2, characterized in that, The frame (1) includes: Crossbeam (15); and A front fork (16) and a rear fork (17) are respectively disposed at both ends of the crossbeam (15), and a handle is provided on the front fork (16).

10. The chainless, high-ratio two-wheeled vehicle as described in claim 9, characterized in that, A seat (18) is provided at one end of the crossbeam (15) near the rear fork (17), and the seat (18) is located above the rear wheel assembly (3).

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