A sleeve folding structure and a power-assisted bicycle

Abstract

The present application relates to the technical field of sleeve folding structure, and discloses a sleeve folding structure and a power-assisted bicycle, wherein the sleeve folding structure comprises a frame assembly and a rotating assembly; the frame assembly comprises a first sleeve, and a rotating seat is arranged outside the first sleeve; the rotating assembly comprises a connecting piece, a first wheel disc, a second wheel disc, a first connecting shaft, a second connecting shaft, a hub and a belt; the rotating assembly can rotate along a rotating shaft to fold or unfold the power-assisted bicycle. The sleeve folding structure can avoid the change of belt tension by optimizing the rotating mechanism, effectively maintain the constant tension of the belt transmission system, prevent the belt from falling off during folding operation, and improve folding smoothness and use reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of sleeve folding structure, specifically relating to a sleeve folding structure and an electric bicycle. Background Technology

[0002] With the diversification of urban travel demands and the popularization of shared mobility, bicycles and e-bikes, due to their lightweight and environmentally friendly characteristics, have become an important part of urban short-distance transportation. To further enhance the portability and ease of storage of these vehicles, folding structures are widely used in these products. By designing the frame to be foldable, users can reduce the vehicle's size without tools, making it easy to carry indoors, store in a car trunk, or use public transportation. In existing folding bike designs, the arrangement of the transmission system has a significant impact on the realization of the folding structure. Compared to traditional metal chains, belt drives are increasingly being used in mid-to-high-end folding and e-bikes due to their advantages such as light weight, low operating noise, and no need for lubrication or maintenance. Belt drive systems typically consist of pulleys and a high-tension ring belt, relying on the meshing between the belt and the pulley teeth to transmit power.

[0003] However, existing folding structures still have significant shortcomings when combined with belt drive systems. Currently, most common folding designs focus on the middle of the frame or the head tube, with the drivetrain typically positioned along the chainstays or rear forks. During folding, the rear triangle of the frame rotates or shifts relative to the front frame, forcing the annular belt connecting the front and rear pulleys to bend, stretch, or twist. Since the belt itself has a specific tension requirement to ensure reliable engagement with the pulleys, the folding operation often alters the center distance or relative angle between the pulleys, disrupting the belt's preset tension. Significant fluctuations or slack in belt tension can easily cause it to disengage from the pulley teeth during or after folding, leading to belt misalignment, jamming, or even complete detachment. This not only hinders the smooth completion of the folding action but may also affect the normal operation of the drivetrain upon re-unfolding due to improper belt reset, potentially damaging drivetrain components. Therefore, effectively maintaining the tension stability of the belt drive system while achieving frame folding functionality and preventing belt detachment during folding has become a pressing technical problem in the design of existing folding bicycles and electric bicycles. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention provides a sleeve folding structure and a power-assisted bicycle to effectively maintain the tension stability of the belt drive system and prevent the belt from falling off during the folding process.

[0005] The technical effects to be achieved by this invention are realized through the following aspects: In a first aspect, the present invention provides a sleeve folding structure, comprising: The frame assembly includes a first sleeve, and a swivel seat is provided on the outer side of the first sleeve; The system includes a rotating assembly, comprising a connector, a first disc, a second disc, a first connecting shaft, a second connecting shaft, a hub, and a belt. The first end of the connector has a rotating portion, and the upper end of the rotating portion has a rotating shaft rotatably connected to the rotating base. The first connecting shaft is rotatably connected to the lower end of the rotating shaft. The first disc is sleeved on the first connecting shaft. The second end of the connector is connected to the second connecting shaft. The hub is rotatably sleeved on the second connecting shaft. The second disc is fixedly connected to the hub, and the belt is sleeved on the outer side of both the first and second discs. The rotating component can rotate along the rotation axis to fold or unfold the electric bicycle.

[0006] In some implementations, the frame assembly further includes a cross tube, the first end of which is connected to the first sleeve, and the second end of which is connected to the front wheel assembly; the cross tube, the first sleeve, and the front wheel assembly enclose a folding space, and the rotating assembly rotates and folds into the folding space along the rotation axis.

[0007] In some implementations, the lower end of the rotating part is provided with a through groove, and bearing seats are respectively connected to both sides of the lower end of the rotating part. The first connecting shaft is installed in the through groove and rotatably connected to the bearing seats. The two ends of the first connecting shaft are also connected to the foot pedal assembly.

[0008] In some implementations, a battery tube is also included, and a locking clip for fixing the battery tube is provided at the upper end of the first sleeve; a second sleeve is also provided at the first end of the connector, and when the electric bicycle is unfolded, the second sleeve is located below the first sleeve, the battery tube is retractably disposed inside the first sleeve and the second sleeve, and the battery tube is fixed by the locking clip; a seat assembly (50) is also provided at the upper end of the battery tube.

[0009] In some implementations, the rotating assembly further includes a rear wheel and a rear frame, the rear wheel being connected to the hub; the rear frame is connected to the connector via at least one link.

[0010] In some implementations, the rear frame is provided with a first latching part, which has a latching groove and a fixed latching member, the fixed latching member being disposed within the latching groove; the first sleeve is provided with a second latching part, which has an elastic latching member that cooperates with the fixed latching member; when the electric bicycle is deployed, the elastic latching member extends into the latching groove and latches with the fixed latching member under elastic force; the second latching part is also provided with a button connected to the elastic latching member to counteract the elastic force of the elastic latching member under pressing force.

[0011] In some implementations, pulleys are provided at the four corners of the rear frame, and the pulleys protrude from the plane of the rear frame so that the electric bicycle can be supported and fixed by the pulleys when folded.

[0012] In some implementations, the rotating assembly further includes an assist motor, which is mounted on the hub and electrically connected to the battery tube to rotate the rear wheel.

[0013] In some implementations, the front wheel assembly includes a head tube, a front wheel, and a front end. The lower end of the head tube is connected to the front wheel, and the upper end of the head tube is connected to the front end via a first folding device, so that the front end folds towards the front wheel along the first folding device. One side of the head tube is connected to the second end of the cross tube via a second folding device, so that the front wheel assembly folds towards the center tube along the second folding device.

[0014] Secondly, the present invention provides an electric bicycle, the electric bicycle including the aforementioned sleeve folding structure.

[0015] In summary, the present invention has at least the following advantages: The sleeve folding structure of the present invention includes a frame assembly and a rotating assembly; the frame assembly includes a first sleeve, and a rotating seat is provided on the outer side of the first sleeve; the rotating assembly includes a connector, a first wheel, a second wheel, a first connecting shaft, a second connecting shaft, a hub, and a belt; the first end of the connector is provided with a rotating part, and the upper end of the rotating part is provided with a rotating shaft rotatably connected to the rotating seat; the first connecting shaft is rotatably connected to the lower end of the rotating shaft; the first wheel is sleeved on the first connecting shaft; the second end of the connector is connected to the second connecting shaft; the hub is rotatably sleeved on the second connecting shaft; the second wheel is fixedly connected to the hub; and the belt is sleeved on the outer side of the first wheel and the second wheel; wherein, the rotating assembly can rotate along the rotating shaft to fold or unfold the electric bicycle. The present invention avoids belt tension changes by optimizing the rotation mechanism, effectively maintains the constant tension of the belt drive system, prevents the belt from falling off during folding operations, and improves folding smoothness and reliability. Attached Figure Description

[0016] Figure 1 This is a side view of the sleeve folding structure according to an embodiment of the present invention; Figure 2 This is a partial perspective view of the sleeve folding structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the overall folding structure of the sleeve according to an embodiment of the present invention; Figure 4 This is a partial folding schematic diagram of the sleeve folding structure according to an embodiment of the present invention.

[0017] Marked in the image: 10. Frame assembly; 11. First sleeve; 12. Cross tube; 14. Locking clip; 15. Rotary seat; 16. Second snap-fit ​​part; 161. Flexible snap-fit ​​element; 162. Button; 20. Rotating assembly; 21. Connector; 211. Rotating part; 212. Rotating shaft; 213. First connecting shaft; 214. Bearing seat; 215. Second sleeve; 22. First wheel disc; 23. Second wheel disc; 24. Belt; 25. Hub; 26. Rear wheel; 27. Rear frame; 271. Pulley; 28. Connecting rod; 29. ​​First locking part; 291. Locking groove; 292. Fixing locking part; 30. Front wheel assembly; 31. Head tube; 32. Front wheel; 33. Front end; 40. Foot pedal assembly; 50. Seat cushion assembly; 60. First folder; 70. Second folder; 80. Battery tube. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are some, but not all, of the embodiments of the present invention.

[0019] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0020] Example 1: Please see the appendix Figures 1-4This invention provides a sleeve folding structure and an electric bicycle to effectively maintain the tension stability of the belt 24 transmission system and prevent the belt 24 from falling off during folding. Specifically, it includes: The frame assembly 10 includes a first sleeve 11, and a swivel seat 15 is provided on the outer side of the first sleeve 11; The rotating assembly 20 includes a connector 21, a first disc 22, a second disc 23, a first connecting shaft 213, a second connecting shaft, a hub, and a belt 24. The first end of the connector 21 is provided with a rotating part 211, and the upper end of the rotating part 211 is provided with a rotating shaft 212 rotatably connected to the rotating seat 15. The first connecting shaft 213 is rotatably connected to the lower end of the rotating shaft. The first disc 22 is sleeved on the first connecting shaft 213. The second end of the connector 21 is connected to the second connecting shaft. The hub is rotatably sleeved on the second connecting shaft. The second disc 23 is fixedly connected to the hub, and the belt 24 is sleeved on the outside of the first disc 22 and the second disc 23. The rotating component 20 can rotate along the rotating axis 212 to fold or unfold the electric bicycle.

[0021] In this embodiment, the design of the sleeve folding structure is intended to optimize the folding performance of the electric bicycle, especially when using a belt drive system.

[0022] Specifically, the sleeve folding structure includes a frame assembly 10, which is the main structure of the electric bicycle. The frame assembly 10 includes a first sleeve 11, which can be a hollow cylindrical or polygonal tube serving as a support part of the frame. A swivel seat 15 is provided on the outer side of the first sleeve 11. The swivel seat 15 can be an annular structure, fixed to the outer surface of the first sleeve 11 by welding, bolting, or integral molding. For example, the swivel seat 15 can be a simple annular flange whose inner hole mates with a rotating shaft 212.

[0023] Furthermore, the sleeve folding structure also includes a rotating assembly 20, which is the core component for realizing the folding function. The rotating assembly 20 includes a connector 21, a first wheel 22, a second wheel 23, a first connecting shaft 213, a second connecting shaft, a hub, and a belt 24. The connector 21 can be a rod-shaped or plate-shaped structure with a certain length and strength, with different functional components supported at its two ends. For example, the connector 21 can be a curved metal arm with an optimized shape to accommodate the folding space.

[0024] The first end of the connector 21 is provided with a rotating part 211. The rotating part 211 can be an integrally formed structure with the connector 21, or it can be fixed to the connector 21 by means of riveting, threaded connection, etc. The upper end of the rotating part 211 is provided with a rotating shaft 212 that is rotatably connected to the rotating seat 15. The rotating shaft 212 can be a simple pin, one end of which is fixed to the rotating part 211, and the other end passes through the hole in the rotating seat 15, and is rotatably connected by a bearing or bushing. For example, the rotating shaft 212 can be a bolt with a shoulder, which is fixed to the rotating part 211 by a nut and rotates through the hole in the rotating seat 15.

[0025] Based on this, the first connecting shaft 213 is rotatably connected to the lower end of the rotating shaft. The first connecting shaft 213 can be a cylindrical shaft, connected to the lower end of the rotating shaft via bearings or bushings to ensure free rotation. For example, the first connecting shaft 213 can be connected by a simple pin passing through a hole at the lower end of the rotating shaft. The first wheel 22 is fitted onto the first connecting shaft 213. The first wheel 22 can be a toothed disc, mounted on the first connecting shaft 213 via interference fit, key connection, or threaded fixing to ensure no slippage during rotation.

[0026] Simultaneously, the second end of the connector 21 is connected to the second connecting shaft. The second connecting shaft can be a cylindrical shaft similar to the first connecting shaft 213, fixed to the second end of the connector 21 by welding, bolting, or integral molding. The hub rotates on the second connecting shaft. The hub can be a hollow cylinder, rotating on the second connecting shaft via bearings or bushings. The second disc 23 is fixedly connected to the hub. The second disc 23 can be a toothed disc similar to the first disc 22, fixed to the outside of the hub by welding, bolting, or interference fit. The connector 21 ensures that the distance between the first and second discs remains constant during rotation, thus maintaining consistent belt tension and preventing the belt from loosening or slipping due to folding.

[0027] Furthermore, belt 24 is sleeved on the outside of the first pulley 22 and the second pulley 23. Belt 24 can be an annular synchronous belt with teeth on its inner side, which mesh with the teeth of the first pulley 22 and the second pulley 23 to achieve power transmission. The tension of belt 24 can be initially set by adjusting the distance between the first pulley 22 and the second pulley 23 or by using a tensioner.

[0028] Thus, the rotating assembly 20 can rotate along the rotation axis 212 to fold or unfold the electric bicycle. When folding is required, the rotating assembly 20 rotates about the rotation axis 212, causing the connector 21 and its belt 24 drivetrain portion to displace relative to the frame assembly 10, thereby reducing the overall size of the vehicle. When unfolding is required, the rotating assembly 20 rotates in the opposite direction, returning the vehicle to a riding position. For example, the frame can be folded or unfolded by manually rotating the connector 21.

[0029] The sleeve folding structure of this invention integrates the belt 24 drive system onto a rotatable connector 21, allowing it to rotate as a whole along the rotation axis 212. This effectively avoids the tension fluctuations, misalignment, or detachment of the belt 24 caused by frame deformation in traditional folding methods. The design ensures the stability and reliability of the belt 24 drive system during folding and unfolding of the electric bicycle, improves the smoothness of the folding operation, and extends the service life of the belt 24, thereby enhancing the portability and user experience of the electric bicycle.

[0030] Example 2: Based on Embodiment 1, the present invention provides a second embodiment of the sleeve folding structure to further illustrate the sleeve folding structure.

[0031] In some embodiments, a horizontal tube 12 is added to the frame assembly 10, the first end of the horizontal tube 12 is connected to the first sleeve 11, and the second end of the horizontal tube 12 is connected to the front wheel assembly 30; the horizontal tube 12, the first sleeve 11, and the front wheel assembly 30 enclose a folding space, and the rotating assembly 20 is rotated and folded into the folding space along the rotation axis 212.

[0032] Specifically, the cross tube 12 is an important component of the frame assembly 10. It typically has a tubular structure and connects different parts of the frame, providing structural support and stability. Its material can be high-strength, lightweight materials, such as aluminum alloy, carbon fiber composites, or high-strength steel, to reduce the overall weight of the vehicle while ensuring strength. The cross-sectional shape of the cross tube 12 can be circular, square, elliptical, or other irregular shapes according to design requirements to optimize its mechanical properties and appearance. The first end of the cross tube 12 is connected to the first sleeve 11, typically through welding, bolting, riveting, or integral molding to achieve a secure connection and ensure the overall rigidity of the frame. The second end of the cross tube 12 is connected to the front wheel assembly 30, also requiring a reliable connection method, such as through the fork headset, bearing housing 214, or a dedicated connector 21, to ensure the steering and support functions of the front wheel assembly 30.

[0033] The front wheel assembly 30 is a crucial component of a power-assisted bicycle, typically comprising the front fork, front wheel 32, handlebars, and related braking system. The front wheel assembly 30 is responsible for steering, support, and some shock absorption. The structural design of the front wheel assembly 30 should consider folding requirements; for example, its connection to the cross tube 12 should allow for appropriate adjustment or separation during folding, or it should have its own folding function. The size and shape of the front wheel assembly 30 affect the formation of the folding space and the overall volume after folding.

[0034] The folding space is a specific area enclosed by the horizontal tube 12, the first sleeve 11, and the front wheel assembly 30. This space is reserved to accommodate the folded rotating assembly 20. The shape and size of the space need to be precisely designed according to the folded dimensions of the rotating assembly 20 to ensure that the rotating assembly 20 can be completely and compactly housed within it, avoiding protrusion or interference with other components. The formation of the folding space makes the folded structure more regular and compact, helps protect internal components, and facilitates transportation and storage.

[0035] The rotating component 20 rotates along the rotation axis 212, which is the core action for achieving the folding of the power-assisted bicycle. When the rotating component 20 rotates, its overall structure undergoes displacement and posture changes. "Folding into the folding space" means that during rotation, the final position of the rotating component 20 is precisely guided and confined within the area enclosed by the cross tube 12, the first sleeve 11, and the front wheel assembly 30. This folding method ensures that the folded rotating component 20 does not swing arbitrarily or occupy extra space, thus achieving a highly integrated and compact folding effect. The folding process may involve the engagement of certain parts of the rotating component 20 with the edges of the folding space, for example, through guide structures or limiting mechanisms to ensure smooth and accurate folding into place.

[0036] Through the above technical solution, based on the aforementioned sleeve folding structure, a horizontal tube 12 is added to the frame assembly 10, with its first end connected to the first sleeve 11 and its second end connected to the front wheel assembly 30. This cleverly utilizes the horizontal tube 12, the first sleeve 11, and the front wheel assembly 30 to form a specific folding space. When the electric bicycle needs to be folded, the rotating component 20 rotates along the rotation axis 212 and is precisely stored within the folding space. This design effectively protects and secures the folded rotating component 20, preventing the folded parts from being exposed externally, thus significantly improving the compactness, stability, and aesthetics of the folding structure. By embedding the rotating component 20 within the folding space formed by the frame, not only is the overall volume after folding effectively reduced, making it convenient for users to carry and store, but it also prevents the folded parts from being accidentally bumped or damaged during transportation or storage, extending the service life of the components. Furthermore, this integrated folding method makes the electric bicycle more neatly arranged in the folded state, improving the user experience.

[0037] In some embodiments, a through groove is provided at the lower end of the rotating part 211, and bearing seats 214 are respectively connected to both sides of the lower end of the rotating part 211. The first connecting shaft 213 is installed in the through groove and rotatably connected to the bearing seats 214. The two ends of the first connecting shaft 213 are also connected to the foot pedal assembly 40.

[0038] Specifically, the through groove at the lower end of the rotating part 211 is an opening or channel penetrating the rotating part 211. Its main function is to provide an internal installation space for the first connecting shaft 213, ensuring that the first connecting shaft 213 can be properly accommodated inside the rotating part 211, thereby making the structure of the entire rotating assembly 20 more compact and providing a foundation for the subsequent installation of the bearing seat 214. The shape and size of the through groove can be designed according to the diameter of the first connecting shaft 213 and the required installation clearance, for example, it can be circular, elliptical or rectangular, and formed by processes such as milling, casting or stamping.

[0039] The bearing seats 214 connected to both sides of the lower end of the rotating part 211 are structural components used to support and fix the bearings. These bearing seats 214 provide precise positioning and stable support points for the first connecting shaft 213, ensuring that the first connecting shaft 213 maintains good concentricity and axial stability during rotation. The bearing seats 214 can be integrally formed with the rotating part 211, for example by casting or forging, or they can be independent components, firmly connected to both sides of the lower end of the rotating part 211 by bolts, welding, or riveting. The material of the bearing seats 214 is usually a high-strength, wear-resistant metal, such as steel or aluminum alloy, to withstand the loads generated during riding and folding.

[0040] The first connecting shaft 213 is installed in the through groove and rotatably connected to the bearing housing 214, meaning that the first connecting shaft 213 passes through the through groove of the rotating part 211, and its two ends respectively mate with the bearings inside the bearing housings 214 on both sides. This installation method allows the first connecting shaft 213 to achieve low-friction, high-precision rotation with the support of the bearings. The bearings can be ball bearings, needle roller bearings, or sliding bearings, etc., and their selection depends on the required load capacity, speed, and requirements for rotational smoothness. The bearings and bearing housings 214, as well as the bearings and the first connecting shaft 213, are usually fitted with an interference fit or a clearance fit, and are axially fixed by means of snap rings, lock nuts, or end caps to prevent axial movement of the first connecting shaft 213 during operation.

[0041] The first connecting shaft 213 is also connected to the pedal assembly 40 at both ends, meaning that the first connecting shaft 213 not only serves as part of the rotating assembly 20 but also directly connects to the pedal assembly 40. The pedal assembly 40 typically includes two left and right pedal cranks and pedals. The two ends of the first connecting shaft 213 can be designed with specific interface forms, such as square, spline, or tapered interfaces, to reliably connect with the corresponding interfaces of the pedal cranks. The connection method can be bolt fixing, key connection, or press fit, to ensure a rigid connection without relative slippage between the pedal assembly 40 and the first connecting shaft 213 during the rider's pedaling process, thereby efficiently transmitting the rider's pedaling force to the first connecting shaft 213.

[0042] Through the above technical solution, a through groove is provided at the lower end of the rotating part 211, and bearing seats 214 are connected to both sides of it, so that the first connecting shaft 213 can be stably installed in the through groove and rotatably connected to the bearing seats 214. This design provides reliable support and a low-friction rotational environment for the first connecting shaft 213, effectively ensuring the smooth transmission of pedaling power. At the same time, the direct connection between the two ends of the first connecting shaft 213 and the pedal assembly 40 allows the rider to efficiently drive the first connecting shaft 213 through the pedal assembly 40, and then transmit power to the entire transmission system through the first wheel 22 and the belt 24. This solution not only optimizes the installation structure of the first connecting shaft 213, keeping it compact during folding, but also significantly improves pedaling efficiency and comfort during riding, effectively solving the problem of stability and smoothness of the first connecting shaft 213 when balancing folding function and pedal transmission.

[0043] In some embodiments, a battery tube 80 is also included. The upper end of the first sleeve 11 is provided with a locking clip 14 for fixing the battery tube 80. The first end of the connector 21 is also provided with a second sleeve 215. When the electric bicycle is unfolded, the second sleeve 215 is located below the first sleeve 11. The battery tube 80 is telescopically disposed inside the first sleeve 11 and the second sleeve 215, and the battery tube 80 is fixed by the locking clip 14. A seat assembly 50 is also provided at the upper end of the battery tube.

[0044] Specifically, the battery tube 80 is a tubular structure used to house and protect the battery of the electric bicycle. It typically integrates a lithium-ion battery pack and may include a battery management system and charging interface. The battery tube 80 is usually made of a lightweight, high-strength metal alloy, such as aluminum alloy, to balance strength, heat dissipation, and lightweight requirements. The locking clip 14 is a mechanical device used to secure the battery tube 80 to the upper end of the first sleeve 11. It typically consists of two or more parts, connected and locked by bolts, clips, or other fasteners, thus forming a circumferential or compression fixation of the battery tube 80. The inner surface of the locking clip 14 may be provided with a cushioning material to reduce vibration and wear between the battery tube 80 and the frame, and to provide a more stable fixation. The second sleeve 215 is part of the first end of the connector 21. It is designed as a tubular structure to mate with the first sleeve 11, with an inner diameter slightly larger than the outer diameter of the battery tube 80, so that the battery tube 80 can slide smoothly within it. When the electric bicycle is deployed, the second sleeve 215 is located below the first sleeve 11, providing internal space for the battery tube 80 together with the first sleeve 11. The battery tube 80 is telescopically disposed inside the first sleeve 11 and the second sleeve 215, meaning that the battery tube 80 can slide along its axial direction inside the two sleeves. This telescopic function can be achieved by providing guide grooves, slide rails, or low-friction coatings on the outer surface of the battery tube 80 or the inner surface of the sleeves to ensure smooth and stable sliding. When the electric bicycle is in the deployed state or a specific operating state, the battery tube 80 is fixed by the locking clip 14, ensuring the stability of the battery during riding and preventing displacement due to vibration or impact.

[0045] Through the aforementioned technical solution, the battery tube 80 is cleverly integrated into the first sleeve 11 of the frame assembly 10 and the second sleeve 215 of the connector 21, and secured with the locking clip 14, achieving a tight connection between the battery and the frame structure. This design allows the battery tube 80 to be stably positioned inside the first sleeve 11 and the second sleeve 215 when the electric bicycle is unfolded, forming an integrated appearance and enhancing the overall aesthetics of the bicycle. More importantly, when the electric bicycle is folded, the battery tube 80 can utilize its telescopic properties to slide and adjust its position within the first sleeve 11 and the second sleeve 215, thereby avoiding interference between the battery and other components of the frame and ensuring a smooth folding process. Simultaneously, the battery tube 80 is encased within the internal structure of the frame, effectively protecting the battery from external impacts and environmental factors, extending its lifespan. This integrated and telescopic battery arrangement not only optimizes the space utilization of the electric bicycle, making the folded size more compact, but also improves the overall structural strength and safety of the bicycle, providing users with a more convenient and reliable riding and folding experience.

[0046] In some embodiments, the rotating assembly 20 further includes a rear wheel 26 and a rear frame 27, the rear wheel 26 being connected to the hub 25; the rear frame 27 being connected to the connector 21 via at least one link 28, and the rear frame 27 being disposed above the rear wheel 26.

[0047] The rear wheel (26" is a crucial component for the movement and support of an electric bicycle. Its main function is to provide driving force and support the weight of the vehicle and the rider. The rear wheel (26) typically consists of a hub, spokes, rim, and tire. Through its connection to the drive mechanism, it transmits power to the ground, propelling the bicycle forward. In electric bicycles, the size, material, and tread design of the rear wheel (26) affect riding comfort, grip, and range.

[0048] The rear rack 27 is a component that provides seating support for the rider, ensuring comfort and stability during riding. The rear rack 27 typically consists of a saddle, seatpost, and connecting mechanism. The shape and padding material of the saddle affect the riding experience, while the seatpost is used to adjust the height of the rear rack 27 to accommodate riders of different heights. The connection method of the rear rack 27 must ensure its stability during bicycle folding and unfolding, and be able to support the rider's weight.

[0049] The connection between the rear wheel 26 and the hub 25 is intended to integrate the rear wheel 26 into the drive system of the electric bicycle. The hub 25, as part of the rotating assembly 20, is connected to the rear wheel 26, allowing power from the drive mechanism to be transmitted to the rear wheel 26, thereby propelling the electric bicycle. The hub 25 can work in conjunction with other transmission components in the rotating assembly 20 (such as the second chainring 23) to form the drive chain of the electric bicycle. Various mechanical connection methods can be used, such as keys, splines, bolts, or welding, to ensure reliable power transmission between the rear wheel 26 and the hub 25.

[0050] The rear frame 27 is connected to the connector 21 via at least one link 28. The link 28, as a structural component connecting the rear frame 27 and the connector 21, provides stable support and ensures the position and posture of the rear frame 27 during the folding and unfolding of the assisted bicycle. The connector 21 is one of the main structures of the rotating assembly 20, with a rotating part 211 at its first end and a second end connected to a second connecting shaft. Connecting the rear frame 27 to the connector 21 via the link 28 allows the rear frame 27 to move synchronously with the folding or unfolding of the rotating assembly 20, thereby reducing the overall volume in the folded state and providing a stable riding position in the unfolded state. The number and geometry of the links 28 can be designed according to actual needs, such as using a single link 28, a double link 28, or a multi-link 28 structure to achieve different support strengths and folding effects.

[0051] The rear rack 27 is positioned above the rear wheel 26, a common practice in bicycle design aimed at optimizing the rider's center of gravity and improving riding stability. Positioning the rear rack 27 above the rear wheel 26 concentrates the rider's weight primarily above the axle of the rear wheel 26, aiding in vehicle balance and providing a comfortable riding posture. This layout also facilitates integration of the rear wheel 26 with the drive system and allows space for the design of a folding mechanism.

[0052] The above technical solution integrates the rear wheel 26 and rear frame 27, essential for the electric bicycle as a means of transportation, into the existing folding structure. The connection between the rear wheel 26 and the hub 25 allows the rear wheel 26 to effectively receive power from the drive system, thus enabling the electric bicycle to move. Simultaneously, the rear frame 27, connected to the connector 21 via the link 28, ensures that the rear frame 27 moves synchronously with the folding and unfolding of the electric bicycle. In the unfolded state, it provides stable seating support for the rider, while in the folded state, it helps reduce the overall size. Positioning the rear frame 27 above the rear wheel 26 further optimizes the rider's center of gravity distribution, improving stability and comfort during riding. Overall, the solution transforms the original folding structure from a semi-finished frame into a fully functional, rideable electric bicycle, greatly enhancing the product's practicality and user experience while maintaining its inherent folding convenience.

[0053] In some embodiments, the rear frame 27 is provided with a first latching portion 29, which has a latching groove 291 and a fixed latching member 292, the fixed latching member 292 being disposed within the latching groove 291; the first sleeve 11 is provided with a second latching portion 16, which has an elastic latching member 161 that cooperates with the fixed latching member 292; when the electric bicycle is deployed, the elastic latching member 161 extends into the latching groove 291 and latches with the fixed latching member 292 under elastic force; the second latching portion 16 is also provided with a button 162 connected to the elastic latching member 161, so as to counteract the elastic force of the elastic latching member 161 under pressing force, thereby separating the elastic latching member 161 from the fixed latching member 292.

[0054] Specifically, the first engaging portion 29 is a structure provided on the rear frame 27, whose main function is to provide a passively engaged interface for the engaging mechanism. It can be a pre-existing structure on the rear frame 27 body, such as a protrusion or recess, or it can be a separately manufactured accessory fixed to the rear frame 27. Its design should ensure sufficient strength and stability to withstand the forces exerted during engagement. The engaging groove 291 is part of the first engaging portion 29, and its shape is a recess or opening for accommodating the insertion of the resilient engaging member 161. The shape and size of the engaging groove 291 must match the head shape of the resilient engaging member 161 to achieve reliable engagement. For example, it can be a rectangular groove, a U-shaped groove, or a hole with a specific profile. The fixing engaging member 292 is disposed inside the engaging groove 291 and is a fixing structure that directly engages with the resilient engaging member 161. It can be a pin, a protrusion, an edge, or a specific geometry within the engaging groove 291. The material of the fixing clip 292 is usually a wear-resistant metal or a high-strength engineering plastic to ensure long-term reliability.

[0055] The second latching part 16 is disposed on the first sleeve 11, corresponding to the first latching part 29 on the rear frame 27. Its function is to support and position the resilient latching member 161 and the button 162. It can be an integrated part of the first sleeve 11 body or a separate module attached to the outside of the first sleeve 11. The resilient latching member 161 is the active component in the latching mechanism, typically containing a spring or other elastic element that tends to extend when no external force is applied. When the assisted bicycle is deployed, the resilient latching member 161 extends into the latching groove 291 of the first latching part 29 under elastic force, forming a mechanical lock with the fixed latching member 292. The head shape of the resilient latching member 161 should match the shape of the fixed latching member 292 and the latching groove 291 to ensure a stable latch. Common implementations include spring pins, spring balls, elastic hooks, or elastic tongues. The button 162 is mechanically connected to the resilient latching member 161 for manual operation to release the latch. When the user presses button 162, the movement of button 162 causes the elastic latch 161 to overcome its elastic force, causing it to disengage from latch slot 291 and fixed latch 292, thereby releasing the locked state. Button 162 can be designed as a press-type, slide-type, or rotary type, and should have good tactile feedback and reliability.

[0056] Through the above technical solution, when the electric bicycle unfolds from the folded state to the riding state, the elastic locking member 161, driven by its own elastic force, automatically extends into the locking groove 291 of the first locking part 29 of the rear frame 27, and forms a stable mechanical locking with the fixed locking member 292. This automatic locking mechanism ensures a firm connection between the rear frame 27 and the first sleeve 11, thereby locking the entire frame structure in the unfolded state, greatly enhancing the overall rigidity and stability of the electric bicycle during riding, and effectively avoiding the risk of accidental folding. When it is necessary to fold the electric bicycle, the user only needs to press the button 162 to counteract the elastic force of the elastic locking member 161, causing it to separate from the fixed locking member 292, thereby unlocking the bicycle and facilitating the folding operation. Through the above technical solution, not only is the safety of using the electric bicycle in the unfolded state improved, but the locking operation during folding and unfolding is also simplified, providing an intuitive and reliable locking and unlocking experience.

[0057] In some embodiments, pulleys 271 are provided at the four corners of the rear frame 27, and the pulleys 271 protrude from the plane of the rear frame 27 so that the electric bicycle can be supported and fixed by the pulleys 271 when folded.

[0058] Specifically, the pulley 271 is a wheel-shaped mechanical component capable of rotating around an axis. Its main function is to provide rolling support and reduce friction, thereby facilitating the movement of the folded electric bicycle. These pulleys 271 can be made of materials such as wear-resistant plastics (e.g., polyurethane, nylon), rubber, or metal, and their size and load-bearing capacity should be matched to the weight of the electric bicycle and the structure of the rear frame 27. The installation method of the pulley 271 can be varied, such as embedded, external, or connected via a dedicated bracket, but it must be ensured that it is firmly connected to the rear frame 27 and can bear all or part of the weight of the bicycle in the folded state. Placing pulleys 271 at the four corners of the rear frame 27 aims to provide uniform multi-point support to enhance overall stability in the folded state.

[0059] The pulley 271 protrudes from the plane of the rear frame 27, meaning that the rolling surface of the pulley 271, or a portion thereof, is lower than the bottom plane of the rear frame 27. This can be achieved by positioning the axis of the pulley 271 below the bottom plane of the rear frame 27, or by designing a special mounting bracket to extend the pulley 271 downwards. For example, the pulley 271 can be installed in a groove at the bottom of the rear frame 27, but its rolling surface is lower than the edge of the groove; or the pulley 271 can be fixed to the corner of the rear frame 27 using an L-shaped bracket, so that the bottom of the pulley 271 is lower than the bottom of the rear frame 27. The height of the protrusion should be carefully designed to ensure that the pulley 271 can effectively contact the ground and provide support when the power-assisted bicycle is folded and placed on the ground, while not causing discomfort to the user or affecting the overall aesthetics and functionality of the vehicle during normal riding. In addition, the protrusion should have sufficient structural strength to reliably support the weight of the power-assisted bicycle in the folded state.

[0060] With the above setup, when the electric bicycle is folded, its center of gravity changes. At this time, the protruding pulleys 271 at the four corners of the rear frame 27 can contact the ground, thus providing stable support for the folded bicycle. This support not only helps keep the bicycle upright and prevents it from tipping over, but also facilitates subsequent movement.

[0061] Through the above technical solution, after the electric bicycle is folded, the protruding pulleys 271 located at the four corners of the rear frame 27 can contact the ground, providing stable multi-point support for the folded bicycle and effectively solving the problem of insufficient stability when the folding bicycle is parked. Furthermore, due to the presence of the pulleys 271, users can easily move the folded bicycle by rolling it without strenuous handling, greatly improving the portability and ease of use of the folding bicycle. The even distribution of the four pulleys 271 ensures stability during movement, effectively avoiding the risk of tipping over, making the folded electric bicycle safer and more convenient to store, transport, or temporarily park.

[0062] In some embodiments, the rotating assembly 20 further includes a power assist motor, which is mounted on the hub and electrically connected to the battery tube 80 to drive the rear wheel to rotate. The rear wheel also includes an outer tire, inner tire, hub, spokes, motor, etc., with the motor shaft mounted on the hub.

[0063] Specifically, an assist motor is an electric motor capable of providing additional power or torque. Its main function in this invention is to provide auxiliary power during the riding of an assisted bicycle. The assist motor can be a DC motor, stepper motor, or servo motor, etc., and the specific selection can be based on a comprehensive consideration of factors such as required torque, speed, control precision, and cost. Typically, the assist motor is also equipped with a reduction gear mechanism to convert the high speed of the motor into the low speed and high torque required by the folding mechanism.

[0064] The power assist motor is mounted on the hub, meaning there is a direct or indirect mechanical connection between the motor and the hub to transmit the motor's output power to the hub. This arrangement allows the motor to be compactly integrated into a key component of the folding mechanism, reducing the complexity of the transmission path. For example, the motor can be connected to the hub via gears, belts, or chains, or the motor itself can be part of the hub, directly driving its rotation.

[0065] Furthermore, the electric connection between the assist motor and battery tube 80 indicates that the power required by the assist motor is provided by the battery tube 80 of the assist bicycle. Battery tube 80 typically houses the power battery of the assist bicycle, providing power to the entire vehicle. By electrically connecting to battery tube 80, the assist motor can directly utilize the bicycle's existing power system, eliminating the need for a separate power source, simplifying the system structure, and ensuring a continuous power supply for the motor. This connection is usually achieved through wires, connectors, and corresponding power management and control circuitry.

[0066] Ultimately, the power assist motor transmits power to the hub via its output shaft or transmission mechanism, enabling it to rotate along the second connecting shaft. This second connecting shaft is a key shaft in the rotating assembly 20; the hub rotates around this shaft, which in turn drives the rear wheel 26 to rotate. The power assist motor's function is to replace or assist manual riding, achieving smooth, controlled rotation of the hub, thereby providing riding assistance.

[0067] The above technical solutions significantly enhance the riding experience of electric bicycles, making riding easier and less strenuous. The design maintains structural simplicity and ensures the reliability of the folding function. The introduction of the electric motor makes riding smoother and less strenuous.

[0068] In some embodiments, the front wheel assembly 30 includes a head tube 31, a front wheel 32, and a handlebar 33. The head tube 31 is a structural component connecting the front wheel 32 to the frame and the handlebar 33. Its lower end is typically connected to the axle of the front wheel 32 via a bearing or quick-release mechanism, while its upper end is connected to the handlebar 33. The head tube may include a connecting portion connected to a first folding mechanism and a second folding mechanism, and a front fork portion connected to the front wheel. The main function of the head tube 31 is to support the front wheel 32, absorb road vibrations, and transmit steering force. The front wheel 32 is the front wheel of the electric bicycle, connected to the frame via the head tube 31, and is responsible for providing rolling support and steering function. The handlebar 33 is the control component of the electric bicycle, typically including handlebars, a stem, etc., used by the rider for steering, braking, and other operations. To achieve a more compact folding mechanism, the lower end of the head tube 31 is connected to the front wheel 32, and the upper end of the head tube 31 is connected to the front of the vehicle 33 via a first folding device 60, allowing the front of the vehicle 33 to fold towards the front wheel 32 along the first folding device 60. The first folding device 60 is a mechanical device capable of folding or pivoting, positioned between the upper end of the head tube 31 and the front of the vehicle 33. The folding device can take various structural forms; for example, it can be a hinge with a quick-locking mechanism, allowing the front of the vehicle 33 to rotate or fold forward or backward (i.e., towards the front wheel 32) around an axis. In the folded state, the front of the vehicle 33 can fit tightly against the head tube 31 or the front wheel 32, significantly reducing its outward protrusion. Furthermore, one side of the head tube 31 is connected to the second end of the cross tube 12 via a second folding device 70, allowing the front wheel assembly 30 to fold towards the center tube along the second folding device 70. The second folding device 70 is another mechanical device that enables folding or pivoting connection, and it is located between one side of the head tube 31 and the second end of the cross tube 12. The folding device can also take the form of a hinge, a quick-release pivot, or a multi-link 28 mechanism. With the second folding device 70, the entire front wheel assembly 30 (including the head tube 31, the front wheel 32, and the folded front end 33) can be rotated or folded about an axis toward the center tube (i.e., toward the first sleeve 11).

[0069] Through the above technical solution, during the folding process of the power-assisted bicycle, the first folding device 60 folds the front end 33 along the direction of the front wheel 32, effectively reducing the outward extension of the front end 33 and preventing it from forming a large protrusion after folding. Then, the second folding device 70 folds the entire front wheel assembly 30 along the center tube direction, allowing the front wheel assembly 30 to fit tightly against the frame body, maximizing the use of the folding space enclosed by the cross tube 12, the first sleeve 11, and the front wheel assembly 30. This step-by-step and coordinated folding mechanism significantly reduces the overall volume and width of the power-assisted bicycle after folding, making it more convenient to store, transport, and carry, greatly improving the user experience and the product's practicality.

[0070] Example 3: Based on Embodiment 1 or Embodiment 2, this invention proposes an embodiment of an electric-assisted bicycle. An electric-assisted bicycle is a mode of transportation that combines a traditional bicycle with an electric drive system. Its core function is to assist the rider through electric power to reduce riding burden, improve riding efficiency, or expand riding range. The electric-assisted bicycle includes the sleeve folding structure described in Embodiment 1 or Embodiment 2 above. The implementation of an electric-assisted bicycle typically includes an electric motor, a battery pack, a controller, and corresponding sensors. The electric motor provides auxiliary power based on the rider's pedaling force or through handlebar control. The battery pack, as the energy source for the electric motor, is typically designed to be rechargeable and easily replaceable or integrated inside the frame. The controller manages the output power of the electric motor and intelligently adjusts it based on sensor data such as cadence and speed. In specific implementations, the electric motor can be a hub motor mounted in the hub of the front wheel 32 or rear wheel 26, or a mid-mounted motor mounted near the crank, while the battery pack is often cleverly integrated inside the frame tubes, such as the downtube, seatpost, or a specially designed battery tube 80, to maintain the simplicity of the overall appearance and structural strength of the bicycle. This design allows the power-assisted bicycle to maintain the basic riding characteristics and handling of a bicycle while providing power assistance.

[0071] By applying the aforementioned sleeve folding structure to electric bicycles, this invention effectively solves the challenges faced by electric bicycles in terms of portability and storage. Electric bicycles, due to the presence of their batteries and motors, are typically heavier and larger than traditional bicycles, making them inconvenient to carry, transport, and store. By introducing the sleeve folding structure, electric bicycles can achieve quick and compact folding, greatly improving their portability and making it convenient for users to take them on public transportation, put them in the trunk of a car, or store them in limited spaces such as at home or in the office. Furthermore, the design of the structure fully considers the unique components of electric bicycles, such as the battery tube 80 and the electric motor, ensuring that these key components are properly protected or integrated during folding, avoiding potential damage or inconvenience caused by folding. For example, the battery tube 80 is retractably housed inside the first sleeve 11 and the second sleeve 215 and secured by the locking clip 14, while the electric motor can be mounted on the hub, working in conjunction with the folding mechanism. This integrated design not only maintains the structural stability and riding performance of the electric bicycle when unfolded, but also forms a compact whole when folded, thus significantly improving the practicality and user experience of the electric bicycle without sacrificing the power assist function.

[0072] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0073] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. These terms are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0074] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," not that the structure must be completely horizontal, but can be slightly tilted.

[0075] In this invention, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0076] Although the description of the invention has been given in conjunction with the specific embodiments described above, it will be apparent to those skilled in the art that many substitutions, modifications, and variations can be made based on the foregoing. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A sleeve folding structure, characterized in that, include: The frame assembly (10) includes a first sleeve (11) with a swivel seat (15) on the outside of the first sleeve (11); And a rotating assembly (20), including a connector (21), a first wheel (22), a second wheel (23), a first connecting shaft (213), a second connecting shaft, a hub (25), and a belt (24). The first end of the connector (21) is provided with a rotating part (211), and the upper end of the rotating part (211) is provided with a rotating shaft (212) rotatably connected to the rotating seat (15). The first connecting shaft (213) is rotatably connected to the lower end of the rotating shaft. The first wheel (22) is sleeved on the first connecting shaft (213). The second end of the connector (21) is connected to the second connecting shaft. The hub (25) is rotatably sleeved on the second connecting shaft. The second wheel (23) is fixedly connected to the hub (25), and the belt (24) is sleeved on the outside of the first wheel (22) and the second wheel (23). The rotating component (20) can rotate along the rotation axis (212) to fold or unfold the electric bicycle.

2. The sleeve folding structure according to claim 1, characterized in that, The frame assembly (10) also includes a cross tube (12), the first end of which is connected to the first sleeve (11), and the second end of which is connected to the front wheel assembly (30); the cross tube (12), the first sleeve (11), and the front wheel assembly (30) enclose a folding space, and the rotating assembly (20) rotates and folds into the folding space along the rotation axis (212).

3. The sleeve folding structure according to claim 2, characterized in that, The lower end of the rotating part (211) is provided with a through groove, and the two sides of the lower end of the rotating part (211) are respectively connected to bearing seats (214). The first connecting shaft (213) is installed in the through groove and is rotatably connected to the bearing seats (214). The two ends of the first connecting shaft (213) are also connected to the foot pedal assembly (40).

4. The sleeve folding structure according to claim 2, characterized in that, It also includes a battery tube (80), and the upper end of the first sleeve (11) is provided with a locking clip (14) for fixing the battery tube (80); the first end of the connector (21) is also provided with a second sleeve (215). When the electric bicycle is unfolded, the second sleeve (215) is located below the first sleeve (11). The battery tube (80) is telescopically disposed inside the first sleeve (11) and the second sleeve (215), and the battery tube (80) is fixed by the locking clip (14); the upper end of the battery tube is also provided with a seat assembly (50).

5. The sleeve folding structure according to claim 4, characterized in that, The rotating assembly (20) also includes a rear wheel (26) and a rear frame (27), the rear wheel (26) being connected to the hub (25); the rear frame (27) being connected to the connector (21) via at least one link (28), and the rear frame (27) being positioned above the rear wheel (26).

6. The sleeve folding structure according to claim 5, characterized in that, The rear frame (27) is provided with a first latching part (29), the first latching part (29) is provided with a latching groove (291) and a fixed latching member (292), the fixed latching member (292) is disposed in the latching groove (291); the first sleeve (11) is provided with a second latching part (16), the second latching part (16) is provided with an elastic latching member (161) that cooperates with the fixed latching member (292); when the electric bicycle is unfolded, the elastic latching member (161) extends into the latching groove (291) and the elastic latching member (161) latches with the fixed latching member (292) under the elastic force; the second latching part (16) is also provided with a button (162) connected to the elastic latching member (161) to counteract the elastic force of the elastic latching member (161) under the pressing force, so that the elastic latching member (161) separates from the fixed latching member (292).

7. The sleeve folding structure according to claim 5, characterized in that, The rear frame (27) is provided with pulleys (271) at the four corners, and the pulleys (271) protrude from the plane of the rear frame (27) so that the electric bicycle can be supported and fixed by the pulleys (271) when folded.

8. The sleeve folding structure according to claim 5, characterized in that, The rotating assembly (20) also includes a power assist motor, which is mounted on the hub and electrically connected to the battery tube (80) to drive the rear wheel to rotate.

9. The sleeve folding structure according to claim 2, characterized in that, The front wheel assembly (30) includes a head tube (31), a front wheel (32), and a front end (33). The lower end of the head tube (31) is connected to the front wheel (32), and the upper end of the head tube (31) is connected to the front end (33) via a first folding device (60) so that the front end (33) is folded towards the front wheel (32) along the first folding device (60). One side of the head tube (31) is connected to the second end of the cross tube (12) via a second folding device (70) so that the front wheel assembly (30) is folded towards the center tube along the second folding device (70).

10. A power-assisted bicycle, characterized in that, The electric bicycle includes the sleeve folding structure as described in any one of claims 1-9.

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