Clutch device on running machine

Abstract

The utility model relates to a clutch device on a running machine, which comprises a central shaft, a wheel, a clutch wheel, a second friction disc and a clutch driving component, and is characterized in that the wheel is rotatably sleeved on the central shaft and is used for supporting a running belt. The clutch wheel is coaxially arranged on the axial side of the wheel and used for being connected with a resistance device. The second friction disc is coaxially nested in the inner side of the end, close to the wheel, of the clutch wheel and is in circumferential linkage with the clutch wheel. The clutch driving assembly is configured to apply axial driving force to the clutch wheel in the combined state, so that the clutch wheel drives the second friction disc to get close to or get away from the wheel in the axial direction. In the clutch connection process, the second friction disc is in contact friction with the wheels firstly, the rotating speed of the wheels is synchronous with the rotating speed of the second friction disc and the rotating speed of the clutch wheel through friction torque, and after the rotating speed is matched, the clutch wheel continues to axially move relative to the second friction disc to form circumferential meshing with the wheels, and combination of a power transmission path is completed. The scheme has the advantage that the synchronization precision and the meshing reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of fitness equipment technology, and in particular to a clutch device on a treadmill. Background Technology

[0002] Non-motorized treadmills, as a type of fitness equipment that relies on the user's own power to drive the running belt, simulate different intensity exercise scenarios, such as running on flat ground and incline training, by adjusting the resistance. Compared with traditional electric treadmills, non-motorized designs have the advantages of energy saving, environmental protection, and compact structure, but they require efficient clutch and resistance adjustment mechanisms to adapt to diverse training needs.

[0003] In existing technologies, such as Chinese patent CN117942527A, a non-powered treadmill is disclosed, which achieves resistance adjustment through the clutch control of the clutch wheel and wheel assembly. This solution mainly employs two clutch methods: a rubber disc scheme and a gripper disc scheme. The rubber disc scheme transmits power through the frictional engagement between the conical rubber disc and the wheel groove, relying on the friction between the rough surface of the rubber disc and the wheel to achieve synchronous rotation. The gripper disc scheme utilizes the tooth meshing structure of the first and second gripper discs for direct transmission, driving the gripper discs to clamp or disengage through a clutch transmission device.

[0004] However, these solutions have significant technical drawbacks. While the rubber disc solution is simple in structure, it suffers from high friction dependence, making it prone to slippage and power transmission failure, especially under high-speed or high-load conditions where resistance stability is poor. Furthermore, the rubber disc requires frequent replacement after long-term wear, resulting in high maintenance costs, and the wear debris can easily contaminate the transmission structure. Although the gripper disc solution can achieve stable transmission, if the gripper discs' rotational speeds are not synchronized during direct engagement, it can easily cause mechanical shock, leading to tooth wear or abnormal noise.

[0005] These technical solutions all have significant limitations when applied independently: the rubber disc solution is prone to slippage and wear due to its frictional characteristics, while the gripper disc solution, although providing stable transmission, is limited by meshing impact and structural redundancy. How to balance synchronization accuracy and meshing reliability has become a pressing technical challenge in this field.

[0006] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0007] In order to solve the above problems, the purpose of this utility model is to provide a clutch device for a treadmill, which has the advantages of improving synchronization accuracy and engagement reliability.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This application provides a clutch device for a treadmill, the technical solution of which is as follows: It includes a central shaft, a wheel, a clutch wheel, a second friction disc, and a clutch drive assembly. The wheel is rotatably mounted on the central shaft to support the running belt. The clutch wheel is coaxially disposed on the axial side of the wheel to connect a resistance device. The second friction disc is coaxially nested inside the end of the clutch wheel near the wheel and is circumferentially linked with the clutch wheel. The clutch drive assembly is configured to apply an axial driving force to the clutch wheel in the engaged state, causing the clutch wheel to drive the second friction disc to move axially closer to or further away from the wheel relative to its axis. During clutch engagement, the second friction disc first contacts and rubs against the wheel, using frictional torque to synchronize the rotational speeds of the wheel, the second friction disc, and the clutch wheel. After the rotational speeds are matched, the clutch wheel continues to move axially relative to the second friction disc until it forms circumferential engagement with the wheel, completing the engagement of the power transmission path.

[0010] Furthermore, this application proposes that a first friction disc is fixedly connected to the end face of the wheel facing the clutch wheel, and the edge of the first friction disc is provided with a first annular tooth. The end face of the clutch wheel facing the wheel is provided with a first concave cavity, and the inner wall of its edge is provided with a second annular tooth. During clutch engagement, the second annular tooth meshes with the first annular tooth to complete the engagement of the power transmission path.

[0011] Furthermore, this application also proposes that the circumferential outer wall of the second friction disc is provided with a third annular tooth. The second friction disc is embedded in the first cavity, and the clutch wheel and the second friction disc are circumferentially linked through the clearance fit between the third annular tooth and the second annular tooth, while allowing the two to move axially relative to each other.

[0012] Furthermore, this application proposes that each tooth of the third annular tooth has a guide boss at its end near the wheel side, with a constriction formed between adjacent guide bosses. The third annular tooth and the second annular tooth are circumferentially clearance-fitted, enabling circumferential linkage between the clutch wheel and the second friction disc while allowing relative axial movement between the two. During clutch engagement, the guide bosses guide the second annular tooth to align and mesh with the first annular tooth.

[0013] Furthermore, this application proposes that the end face of the first friction disk facing the second friction disk is recessed to form a second cavity. The end of the second friction disk is a truncated cone, which can be embedded into the second cavity and cooperate with the first friction disk.

[0014] Furthermore, this application also proposes that a first wear-resistant ring of rigid material is fixedly connected to the end face of the first friction disc, which includes an annular plane covering the end face and an annular conical surface extending into the second cavity. The outer edge of the annular plane is provided with first annular guide teeth that engage with the first annular teeth, each of the first annular guide teeth having a guide tooth tip. The conical platform of the second friction disc mates with the annular conical surface.

[0015] Furthermore, this application also proposes that a second wear-resistant ring of rigid material is fixed to the end face of the clutch wheel, and a second annular guide tooth is provided on the inner diameter edge of the ring to engage with the second annular tooth, and each second annular guide tooth has a guide tooth tip.

[0016] Furthermore, this application also proposes that a support spring is sleeved on the central shaft between the second friction disc and the clutch wheel, with its two ends directly or indirectly supporting the second friction disc and the clutch wheel. During clutch engagement, the clutch wheel pushes the second friction disc to move axially through the support spring.

[0017] Furthermore, this application proposes that the circumferential outer wall of the second friction disc is provided with multiple sets of elastic push block assemblies, each set including a movable push block and a spring between the push block and the second friction disc. The inner wall of the first recessed cavity of the clutch wheel is provided with a pushing groove. The push block is embedded in the pushing groove and engages with the inclined surface of the pushing groove. During clutch engagement, when the second friction disc can no longer move axially, the pushing groove of the clutch wheel drives the push block to radially compress the spring.

[0018] Furthermore, this application proposes that the clutch drive assembly includes a clutch actuator disc, a cam disc, a fixed bushing, and a sliding bushing. The clutch actuator disc and the cam disc are coaxially mounted on a shaft passing through the fixed bushing. The protruding end of the cam disc is connected to the sliding bushing via a connecting plate, and the clutch wheel is rotatably mounted on the sliding bushing via a bearing. A tension spring is provided between the sliding bushing and the fixed bushing to provide a reset force.

[0019] As can be seen from the above, the clutch device and its clutch drive assembly, wear-resistant ring and elastic push block assembly provided in this application include a central shaft, wheel, clutch wheel, second friction disc and clutch drive assembly. During the clutch engagement process, the second friction disc first contacts to achieve speed synchronization, and then completes the gear meshing transmission, which has the advantages of improving synchronization accuracy and meshing reliability. Attached Figure Description

[0020] Figure 1 This is a three-dimensional schematic diagram of a clutch device on a treadmill.

[0021] Figure 2 This is a schematic diagram of the end face of a clutch device on a treadmill.

[0022] Figure 3 for Figure 2 AA sectional view.

[0023] Figure 4 This is a front view of a clutch device on a treadmill.

[0024] Figure 5 for Figure 4 BB cross-sectional view.

[0025] Figure 6This is an exploded view of the structure of a clutch device on a treadmill.

[0026] Figure 7 for Figure 6 Enlarged view of part A in the image.

[0027] Figure 8 for Figure 6 Enlarged view of part B in the image. Detailed Implementation

[0028] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and 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 this utility model.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more, unless otherwise expressly defined.

[0031] In this utility model, 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 connection. 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, or a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0032] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can 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 top" of the second 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 second 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.

[0033] To address the existing problems described in the background art, researchers observed inherent defects in pure friction or pure meshing schemes and attempted to find a synergistic mechanism combining both. Initially, the idea was to solve the problem of speed synchronization and power transmission separation through phased operation, but it was necessary to ensure that the two phases were continuous and interference-free. Further research revealed that prioritizing frictional contact to forcibly eliminate speed differences during clutch engagement, followed by locking the transmission path through rigid meshing, effectively prevents impact and slippage. To achieve this goal, a second friction disc capable of axial movement and linked to the clutch wheel needs to be designed, while a drive assembly is set up to precisely control the axial displacement timing of the clutch wheel.

[0034] like Figure 1-8 As shown, this application proposes a clutch device for a treadmill, including a central shaft 1, a wheel 2, a clutch wheel 3, a second friction disc 4, and a clutch drive assembly 5. The wheel 2 is rotatably mounted on the central shaft 1 to support the running belt. The clutch wheel 3 is coaxially disposed on the axial side of the wheel 2 to connect a resistance device. The second friction disc 4 is coaxially nested inside the end of the clutch wheel 3 near the wheel 2 and is circumferentially linked with the clutch wheel 3. The clutch drive assembly 5 is configured to apply an axial driving force to the clutch wheel 3 in the engaged state, causing the clutch wheel 3 to drive the second friction disc 4 to move axially closer to or further away from the wheel 2 relative to the wheel 2. During clutch engagement, the second friction disc 4 first contacts and rubs against the wheel 2 to synchronize the rotational speeds of the wheel 2, the second friction disc 4, and the clutch wheel 3 through frictional torque. After the rotational speeds are matched, the clutch wheel 3 continues to move axially relative to the second friction disc 4 until it forms a circumferential engagement with the wheel 2, completing the engagement of the power transmission path.

[0035] In this design, the central shaft 1 refers to the shaft that passes through the device and provides rotational support. It can be made of a high-rigidity metal material and is used to fix the relative positions of the wheel 2 and the clutch wheel 3. The wheel 2 is the rotating component that carries the running belt and transmits power. Its end face can be equipped with a ring-shaped tooth structure for meshing with the clutch wheel 3. The clutch wheel 3 is the component that connects to the resistance device and transmits torque. Its internal cavity can accommodate the second friction disc 4, and the rotational freedom of the second friction disc 4 is restricted by a circumferential linkage structure. The second friction disc 4 is a disc with a friction surface and a meshing structure. It can be made of wear-resistant composite material, and its end generates frictional torque when it contacts the wheel 2. The clutch drive assembly 5 is the actuator that controls the axial movement of the clutch wheel 3. Specifically, it can adopt the traction clutch device or shift fork clutch device described in Chinese Patent CN117942527A.

[0036] Specifically, when the user starts the treadmill, the clutch drive assembly 5 pushes the clutch wheel 3 towards the wheel 2, causing the second friction disc 4 to contact the end face of the wheel 2. This includes a direct contact with the wheel 2, as described below, and a contact with the first friction disc 20 on the wheel 2. The frictional contact between the second friction disc 4 and the wheel 2 generates a resistance torque, which on the one hand slows down the wheel 2, and on the other hand drives the clutch wheel 3 to rotate until the wheel 2 and the clutch wheel 3 are forced to synchronize their speeds. Once the speed difference is eliminated, the clutch wheel 3 continues to move axially, causing the second annular tooth 31 on the end face of the clutch wheel 3 to mesh with the first annular tooth 21 on the end face of the wheel 2, forming a rigid transmission path. During this process, the circumferential linkage between the second friction disc 4 and the clutch wheel 3 allows them to rotate synchronously, while the axial relative movement ensures the precise execution of the engagement action. The support spring 8 is disposed between the clutch wheel 3 and the second friction disc 4, providing a restoring force when disengaged, maintaining the separation of the second friction disc 4 from the wheel 2.

[0037] Compared to existing technologies, traditional friction drive systems are prone to wear and slippage due to their reliance on a single friction surface, while purely rigid meshing systems generate impacts when speeds are not synchronized. This solution employs a phased clutch mechanism, first using frictional contact to force synchronized speeds, and then achieving stable transmission through gear meshing. This avoids the impact problems of rigid meshing and eliminates the slippage risk of friction drives. In existing technologies, the rubber disc and the gripper disc work independently, failing to coordinate and optimize the synchronization and meshing process. This solution significantly improves the smoothness and reliability of the clutch process through structural integration and action timing control. Through the above technical solutions, this application achieves separate control of speed synchronization and power transmission during the clutch process, reducing mechanical impact and component wear caused by speed differences. The linkage design between the second friction disc 4 and the clutch wheel 3 ensures seamless connection between the two stages of action, avoiding interruption of power transmission. The rigid meshing structure locks the transmission path after synchronization, improving the stability of resistance adjustment and making it suitable for high-load scenarios such as high-speed running. When users switch between different training intensities, the clutch device can respond quickly and maintain continuous power transmission, improving the stability and lifespan of the treadmill.

[0038] In a specific implementation plan, a first friction disc 20 is provided on the end face of the wheel 2 facing the clutch wheel 3, and a first annular tooth 21 is provided on the edge of the first friction disc 20. A first cavity 32 with a second annular tooth 31 is provided on the end face of the clutch wheel 3 facing the wheel 2. The power transmission path is combined by the engagement of the second annular tooth 31 and the first annular tooth 21 during the clutch engagement process.

[0039] The first friction disc 20 can be bolted, snap-fitted, or integrally formed onto the wheel 2. The first annular tooth 21 refers to a tooth-like structure distributed circumferentially along the edge of the end face of the wheel 2, which serves to form a rigid transmission connection through meshing with the second annular tooth 31. The second annular tooth 31 refers to a corresponding tooth-like structure set on the inner wall of the edge of the first recess 32 on the end face of the clutch wheel 3. Its tooth spacing is configured to be greater than the tooth thickness of the first annular tooth 21 so as to achieve interference-free meshing after the speed is synchronized. The first recess 32 refers to an annular space formed by the inward concavity of the end face of the clutch wheel 3. Its axial depth is set to accommodate the protruding structure on the end face of the wheel 2, providing clearance space for tooth meshing during the clutch process.

[0040] Specifically, when the clutch drive assembly 5 pushes the clutch wheel 3 to move axially, the first annular tooth 21 on the end face of the first friction disc 20 and the second annular tooth 31 in the first cavity 32 of the clutch wheel 3 form an axial relative motion. In the initial contact stage, the second friction disc 4 and the first friction disc 20 on the wheel 2 achieve speed synchronization through frictional torque. At this time, the tooth grooves of the first annular tooth 21 and the second annular tooth 31 gradually approach each other and gradually align during rotation. When the speed difference is eliminated, the clutch wheel 3 continues to move axially, and the tooth tip of the second annular tooth 31 slides into the tooth groove along the tooth profile of the first annular tooth 21 to complete the meshing. At this time, the power transmission path switches from friction transmission to tooth meshing transmission. The spatial design of the first cavity 32 allows the end face of the wheel 2 to partially extend into the clutch wheel 3, ensuring that the tooth surface contact area is located at the optimal position for torque transmission in the transmission system during meshing.

[0041] Compared to existing technologies, the gripper disc scheme in Chinese patent CN117942527A directly engages the teeth without eliminating the speed difference, which easily leads to tooth surface impact and abnormal noise. This solution, by setting a first concave cavity 32 to accommodate the meshing action and eliminating the speed difference based on the friction synchronization stage, ensures that the tooth meshing only occurs under phase alignment. Compared to the disc scheme that relies on friction to maintain transmission, this solution converts to tooth meshing after synchronization, avoiding long-term frictional wear and overcoming the impact defects of direct meshing. Through the above technical solution, this application effectively reduces the mechanical impact energy during meshing, reducing tooth surface wear and impact noise. Precise meshing after speed synchronization avoids local stress concentration caused by tooth misalignment, improving the meshing accuracy of the transmission system. After rigid tooth meshing replaces friction transmission, power transmission efficiency is stably guaranteed, while reducing maintenance needs caused by friction material wear.

[0042] Furthermore, a third annular tooth 41 is provided on the circumferential outer wall of the second friction disk 4, and the second friction disk 4 is embedded in the first cavity 32. The clutch wheel 3 and the second friction disk 4 are circumferentially linked through the clearance fit between the third annular tooth 41 and the second annular tooth 31, while allowing axial relative movement between the two. The third annular tooth 41 refers to a continuous or discontinuous tooth structure distributed along the outer circumference of the second friction disk 4, specifically using trapezoidal cross-section teeth or involute tooth shapes. The tooth tip maintains an axial clearance with the tooth root of the second annular tooth 31. Its function is to transmit circumferential torque through the tooth clearance while avoiding mechanical interference during axial movement. The clearance fit means that there is circumferential displacement space between the third annular tooth 41 and the second annular tooth 31, specifically using a tooth width difference fit or a tooth side clearance fit. Its function is to allow the clutch wheel 3 and the second friction disk 4 to maintain circumferential synchronization during axial movement, while eliminating the motion resistance generated by rigid contact. The first concave cavity 32 refers to the annular cavity provided on the end face of the clutch wheel 3, which can be implemented using a stepped cavity structure. Its function is to form an axial movement guide space for the second friction disc 4, and at the same time, to constrain the radial displacement of the second friction disc 4 through the inner wall of the cavity.

[0043] Specifically, during the axial movement of the clutch wheel 3, circumferential force is transmitted between the tooth flanks of the third ring tooth 41 and the second ring tooth 31, causing the second friction disc 4 to drive the clutch wheel 3 to rotate synchronously. As the clutch wheel 3 continues to move axially, the third ring tooth 41 slides relative to the tooth groove of the second ring tooth 31 until the wheel 2 achieves synchronized rotational speed. When the clutch wheel 3 moves further, the second ring tooth 31 moves axially along the third ring tooth 41 and begins to engage and lock with the first ring tooth 21 of the wheel 2. During this process, the clearance fit between the third ring tooth 41 and the second ring tooth 31 maintains the stability of the transmission synchronization and releases axial movement space for subsequent engagement. Through the above technical solution, this application effectively solves the technical contradiction of maintaining circumferential linkage and avoiding meshing interference between the clutch wheel 3 and the second friction disc 4 during axial movement. The tooth profile structure with clearance fit achieves the decoupling of power transmission in the friction synchronization stage and displacement in the axial movement stage, ensuring that the ring tooth can be accurately guided to engage after speed synchronization, thus improving the working reliability of the clutch device.

[0044] Furthermore, a guide boss 411 is provided at the end of each tooth of the third annular tooth 41 near the wheel 2 side, and a constriction 412 is formed between adjacent guide bosses 411. During clutch engagement, the guide bosses 411 guide the second annular tooth 31 so that the second annular tooth 31 aligns and meshes with the first annular tooth 21. The guide boss 411 refers to the protruding structure extending from the end of the third annular tooth 41 towards the wheel 2 side, which can be implemented using trapezoidal or arc-shaped protrusions, used to physically contact and constrain the movement path of the second annular tooth 31 during axial movement. The constriction 412 refers to the gap area formed between adjacent guide bosses 411, used to accommodate the tooth tip of the second annular tooth 31 and guide it to slide into a predetermined position when the clutch wheel 3 moves axially. The circumferential clearance fit refers to a tooth groove fit between the third annular tooth 41 and the second annular tooth 31 with a gap, which can be implemented using a design where the tooth width is slightly smaller than the tooth groove width, used to allow axial relative displacement while maintaining circumferential rotational synchronization.

[0045] Specifically, during clutch engagement, the clutch wheel 3 moves axially towards the wheel 2 under the influence of driving force. At this time, the second friction disc 4 has synchronized the rotational speed of the wheel 2 with that of the clutch wheel 3 through frictional torque. The guide boss 411 first contacts the tooth side of the second ring tooth 31, forcing the second ring tooth 31 to slide into the gap of the constriction 412 through the inclined surface or arc surface. As the axial movement continues, the tooth tip of the second ring tooth 31 is guided by the gap of the constriction 412 to be completely aligned with the first ring tooth 21 of the wheel 2, ultimately achieving impact-free engagement. The circumferential clearance fit allows the clutch wheel 3 and the second friction disc 4 to adaptively adjust their relative positions during axial movement, avoiding jamming caused by assembly errors or part deformation. Through the above technical solution, this application solves the problem of misalignment caused by axial movement trajectory deviation of the ring teeth of the clutch wheel 3 and the wheel 2 during engagement, ensuring that after the rotational speed is synchronized, the second ring tooth 31 can slide into the tooth groove of the first ring tooth 21 along a predetermined path to complete rigid engagement. This structure significantly reduces the risk of impact wear caused by tooth misalignment, while also reducing the frequency of manual maintenance.

[0046] like Figure 3 and 5As shown, a second concave cavity 22 is formed by the recessed end face of the first friction disc 20 on the wheel 2 facing the second friction disc 4. The end of the second friction disc 4 is a conical platform 42, which can be embedded into the second concave cavity 22 and cooperate with the first friction disc 20. The second concave cavity 22 refers to the annular recessed area formed by machining the end face of the first friction disc 20 facing the second friction disc 4. Its function is to provide axial embedding space for the conical platform 42 of the second friction disc 4 and limit the radial displacement of the second friction disc 4 during the contact phase. The conical platform 42 refers to the truncated cone structure formed by the transition of the conical surface at the end of the second friction disc 4. It can be achieved by machining or injection molding. Utilizing the geometric fit between the conical surface and the second concave cavity 22, a gradually expanding friction contact area is formed during the initial contact phase.

[0047] Specifically, when the clutch drive assembly 5 pushes the second friction disc 4 closer to the wheel 2, the conical platform 42 of the second friction disc 4 first engages with the second cavity 22. The outer conical surface of the conical platform 42 contacts the inner wall of the second cavity 22. During axial movement, the self-centering effect of the conical surface guides the second friction disc 4 to remain coaxial with the wheel 2, avoiding eccentric friction caused by assembly errors or vibration. As the clutch wheel 3 continues to apply axial driving force, the contact area between the conical platform 42 and the second cavity 22 gradually increases, and the friction torque increases smoothly until the wheel 2 and the second friction disc 4 reach synchronized rotational speed. During this process, the second cavity 22 constrains the radial movement of the conical platform 42, preventing centrifugal force or external impact from causing the second friction disc 4 to disengage from the predetermined contact position. Through the above technical solution, this application improves the alignment accuracy through the geometric fit between the conical platform 42 and the second cavity 22 during the contact process between the second friction disc 4 and the first friction disc 20, ensuring uniform force on the friction surface and reducing local wear. By suppressing radial offset through the self-centering effect of the conical surface, contact stability is enhanced, thereby reducing the risk of power transmission failure caused by misalignment of the friction surface and extending the maintenance cycle of the clutch device.

[0048] Furthermore, a first wear-resistant ring 6 made of rigid material is fixed to the end face of the first friction disk 20. The first wear-resistant ring 6 includes an annular plane 61 covering the end face and an annular conical surface 62 extending into the second cavity 22. The outer edge of the annular plane 61 is provided with first annular guide teeth 63 that engage with the first annular teeth 21. Each first annular guide tooth 63 has a guide tooth tip. The conical platform 42 of the second friction disk 4 mates with the annular conical surface 62. The first wear-resistant ring 6 refers to an annular component fixed to the end face of the first friction disk 20 by welding or bolting. Specifically, it can be made of quenched steel, aluminum alloy, or ceramic composite material. Its annular plane 61 is used to bear the axial pressure transmitted by the second friction disk 4, and the annular conical surface 62 is used to form a conical contact with the conical platform 42 of the second friction disk 4. The annular conical surface 62 refers to an inclined surface extending from the inner edge of the annular plane 61 into the interior of the second cavity 22. Its mating with the conical platform 42 increases the frictional contact area. The first annular guide tooth 63 refers to the tooth-shaped structure set on the outer edge of the annular plane 61. Its guide tooth tip is a tapered wedge shape, which is used to guide the second annular tooth 31 to align with the tooth groove of the first annular tooth 21 during the axial movement of the clutch wheel 3.

[0049] Specifically, when the clutch wheel 3 pushes the second friction disc 4 towards the wheel 2, the conical platform 42 first forms a conical friction contact with the annular conical surface 62. This contact method reduces the pressure per unit area by increasing the effective contact area, thereby delaying end face wear. After the speed is synchronized, the clutch wheel 3 continues to move axially. At this time, the guide tooth tip of the first annular guide tooth 63 contacts the second annular tooth 31. The wedge-shaped guide surface forces the second annular tooth 31 to make a slight adjustment in position circumferentially until the tooth grooves of the first annular tooth 21 and the second annular tooth 31 are completely aligned. At this time, the annular teeth enter the meshing and locking state. During this process, the rigid material of the first wear-resistant ring 6 can avoid tooth misalignment caused by extrusion deformation, while the self-centering effect generated by the conical contact further ensures the axial alignment of the meshing process. Through the above technical solution, this application effectively reduces the local wear rate of the contact surface between the first friction disk 20 and the second friction disk 4, avoids the problem of transmission path loosening caused by end face wear, and eliminates the impact load in the tooth meshing process through the forced alignment function of the guide tooth tip, ensuring a smooth and impact-free clutching process.

[0050] Furthermore, a second wear-resistant ring 7 made of rigid material is fixed to the end face of the clutch wheel 3. The inner diameter edge of the ring 7 is provided with second annular guide teeth 71 that engage with the second annular teeth 31. Each second annular guide tooth 71 has a guide tooth tip. The second wear-resistant ring 7 refers to the annular component covering the end face of the clutch wheel 3, which can be made of hardened steel, aluminum alloy, or other hard alloy materials. This component enhances the wear resistance and impact resistance of the clutch wheel 3 end face. The second annular guide tooth 71 refers to a continuous tooth structure located on the inner diameter edge of the second wear-resistant ring 7. The tooth tip width can be smaller than the tooth groove width of the second annular tooth 31. This structure guides the axial movement trajectory of the clutch wheel 3 during the initial engagement stage. The guide tooth tip refers to the acute-angled structure at the tip of the second annular guide tooth 71. This structure forms a preferential contact point when the tooth surfaces contact to guide the tooth groove alignment.

[0051] Specifically, after the rigid second wear-resistant ring 7 is fixed to the end face of the clutch wheel 3, the second annular guide tooth 71 on its inner diameter edge forms a continuous connection structure with the original second annular tooth 31 of the clutch wheel 3. When the clutch wheel 3 moves axially towards the wheel 2, the guide tooth tip of the second annular guide tooth 71 first contacts the first annular tooth 21 on the end face of the wheel 2. At this time, the acute angle structure of the guide tooth tip can cut into the tooth tip gap of the first annular tooth 21, guiding the clutch wheel 3 and the wheel 2 to automatically correct their circumferential positions through geometric interference. As the axial pressure continues to be applied, the second annular tooth 31 gradually slides into the tooth groove of the first annular tooth 21 under the guidance of the guide tooth tip until the two form a fully meshed state.

[0052] Through the above technical solution, this application solves the problems of tooth wear and meshing difficulties caused by asynchronous rotation speeds during the engagement of the clutch wheel 3 and the wheel 2. The preferential contact characteristic of the guide tooth tip enables the clutch wheel 3 to automatically correct circumferential position deviations during axial movement, reducing tooth surface friction loss. The rigid support of the second wear-resistant ring 7 prevents plastic deformation of the guide teeth during repeated engagement operations, ensuring the long-term effectiveness of the guiding function.

[0053] The above scheme uses the first annular guide tooth 63 and the second annular guide tooth 71 to cooperate, which enables the clutch wheel 3 to engage with the wheel 2 quickly and smoothly.

[0054] like Figure 3 , 5 As shown in Figure 7, a support spring 8 is sleeved on the central shaft 1 between the second friction disc 4 and the clutch wheel 3. Its two ends are directly or indirectly supported by the second friction disc 4 and the clutch wheel 3. During the clutch engagement process, the clutch wheel 3 pushes the second friction disc 4 to move axially through the support spring 8.

[0055] The support spring 8 is an elastic element sleeved on the central shaft 1 and located between the second friction disc 4 and the clutch wheel 3. It can be implemented using a helical spring or a disc spring. When compressed, this spring stores elastic potential energy, and when released, it generates axial thrust. The function of this spring is to provide buffering force through elastic deformation during the initial axial movement of the clutch wheel 3, avoiding impact from rigid contact. Indirect support means that one end of the support spring 8 is in direct contact with the clutch wheel 3 or the second friction disc 4, and the other end is connected to the second friction disc 4 or the clutch wheel 3 through an intermediate structural component. This can be achieved using a spring seat, a washer, or the sliding bushing 54 described below as an intermediate force transmission component. This method allows the spring to maintain stable support during axial movement. The function of this structure is to optimize the transmission path of the spring force and adapt to changes in the relative displacement between the clutch wheel 3 and the second friction disc 4. Direct support means that both ends of the support spring 8 are in direct contact with the end faces of the clutch wheel 3 and the second friction disc 4, respectively. This can be achieved by machining the spring ends into flat or curved surfaces. This method simplifies the hierarchy of the force transmission chain. The purpose of this structure is to reduce energy loss in the intermediate links and ensure that the axial thrust is applied efficiently to the second friction disk 4.

[0056] Specifically, after the clutch drive assembly 5 is activated, the clutch wheel 3 begins to move axially along the central axis 1. The support spring 8 is compressed by the moving end of the clutch wheel 3, and its elastic force pushes the second friction disc 4 towards the wheel 2. At this time, the second friction disc 4 contacts the wheel 2 and generates a frictional torque, causing the two to rotate at the same speed. When the speed difference is eliminated, the clutch wheel 3 continues to move axially against the spring resistance until its second ring tooth 31 is fully engaged with the first ring tooth 21 of the wheel 2. During this process, the elastic deformation of the support spring 8 determines the gradient of the contact pressure between the second friction disc 4 and the wheel 2, avoiding slippage or wear caused by sudden changes in contact surface pressure. Through the above technical solution, this application solves the coordination problem of axial movement control between the second friction disc 4 and the clutch wheel 3 during clutch engagement. The elastic support of the support spring 8 enables the second friction disc 4 to adaptively adjust the pressure when contacting the wheel 2, avoiding instantaneous overload caused by speed difference. Meanwhile, after synchronization is completed, clutch wheel 3 disengages from the spring constraint and continues to move, ensuring sufficient axial driving force when the teeth mesh, thereby achieving a smooth switching of the power transmission path under impact-free conditions.

[0057] like Figure 5 and 7As shown, multiple sets of elastic push block assemblies 9 are provided on the circumferential outer wall of the second friction disk 4. Each set includes a movable push block 91 and a spring 92 between the push block 91 and the second friction disk 4. A pushing groove 33 is provided on the inner wall of the first cavity 32 of the clutch wheel 3. The push block 91 is embedded in the pushing groove 33 and cooperates with the inclined surface of the pushing groove 33. During the clutch engagement process, when the second friction disk 4 can no longer move axially, the pushing groove 33 of the clutch wheel 3 drives the push block 91 to radially compress the spring 92. The elastic push block assembly 9 refers to a transmission unit with radial elastic deformation capability composed of the push block 91 and the spring 92. Specifically, it can be implemented by opening an installation groove in the circumference of the second friction disk 4 and embedding the push block 91, and setting a helical spring at the bottom of the push block 91 and the installation groove. Its function is to absorb the driving force through elastic deformation when the axial movement of the clutch wheel 3 is obstructed, and avoid rigid impact. The push groove 33 refers to the inclined groove on the inner wall of the clutch wheel 3. Specifically, it can be designed using a combination of an inclined wall surface and an arc-shaped transition structure. Its function is to convert the axial driving force into a radial component force through the contact between the inclined surface and the push block 91, thereby triggering the radial displacement of the push block 91. The inclined surface engagement refers to the sliding pair formed by the inclined contact surfaces of the push block 91 and the push groove 33. This can be achieved by setting an arc surface at the end of the push block 91 to match the inclined surface of the push groove 33. Its function is to convert the axial movement of the clutch wheel 3 into the radial compression movement of the push block 91, realizing dynamic adjustment of the power transmission path.

[0058] Specifically, in the initial stage of clutch engagement, the second friction disc 4 has not reached its axial movement limit. At this time, the clutch wheel 3 synchronously pushes the second friction disc 4 towards the wheel 2 via the elastic push block assembly 9, and the spring 92 is in a free state. When the second friction disc 4 can no longer move axially after contacting the wheel 2, the clutch wheel 3 continues to advance axially under the driving force. The inclined surface of the push groove 33 begins to squeeze the push block 91, forcing the push block 91 to compress the spring 92 radially inward. During this process, the sliding cooperation between the inclined surface and the push block 91 converts the axial driving force into the radial elastic potential energy of the spring 92. The radial avoidance of the push block 91 allows the clutch wheel 3 to continue moving relative to the second friction disc 4 until the second ring tooth 31 and the first ring tooth 21 complete engagement. The compression deformation of the spring 92 provides a buffer space for the subsequent action of the clutch wheel 3, avoiding mechanical impact caused by motion interference. Through the above technical solution, this application effectively solves the mechanical impact problem caused by the concentrated transmission of driving force of clutch wheel 3 when the axial movement of the second friction disc 4 is blocked. Through the radial avoidance of elastic push block 91 and the buffering effect of spring 92, it ensures that clutch wheel 3 can still smoothly complete the meshing action after the speed is synchronized, reducing the risk of component wear and improving the transmission reliability of clutch device under high speed or high load conditions.

[0059] like Figure 5 and 8As shown, the clutch drive assembly 5 includes a clutch actuator disc 51, a cam disc 52, a fixed bushing 53, and a sliding bushing 54. The clutch actuator disc 51 and the cam disc 52 are coaxially mounted on a shaft 55 passing through the fixed bushing 53. The protruding end of the cam disc 52 is connected to the sliding bushing 54 via a connecting plate 56, and the clutch wheel 3 is rotatably mounted on the sliding bushing 54 via a bearing 57. A tension spring 58 is provided between the sliding bushing 54 and the fixed bushing 53 to provide a reset force.

[0060] The clutch actuator disk 51 is a rotating component that receives external driving force. It can be implemented as a metal disk with a keyway, and its synchronous rotation is achieved by connecting it to the shaft 55 via a key. The cam disk 52 is a disk with an eccentric protrusion structure, which can be implemented as a split cam structure. Its protruding end is hinged to the connecting plate 56 via a pin, converting the rotational motion of the clutch actuator disk 51 into the axial displacement of the sliding sleeve 54. The fixed sleeve 53 is a sleeve that is fixedly connected to the central shaft 1, which can be achieved by interference fit or bolt fixing, providing a guiding reference for the axial movement of the sliding sleeve 54. The sliding sleeve 54 is a sleeve that can slide axially along the outer wall of the fixed sleeve 53, and can be made of a low-friction copper alloy material. Internally, it supports the clutch wheel 3 via a rolling bearing 57, achieving decoupling of axial driving force transmission and rotational freedom. Among them, tension spring 58 refers to a helical spring that provides reset elasticity. Specifically, it can be implemented by a bidirectional tension spring with adjustable preload. Its two ends are hooked to the lug structure of the fixed bushing 53 and the sliding bushing 54 respectively, to ensure that the clutch wheel 3 automatically returns to its original position in the non-drive state.

[0061] Specifically, the clutch actuator disc 51 and the cam disc 52 are coaxially mounted on the shaft 55. When an external driving force drives the clutch actuator disc 51 to rotate, the eccentric protrusion of the cam disc 52 pushes the sliding sleeve 54 to move axially along the fixed sleeve 53 via the connecting plate 56. The sliding sleeve 54 drives the clutch wheel 3 to move closer to the wheel 2 via the bearing 57. At this time, the second friction disc 4 contacts the wheel 2 and completes speed synchronization. After speed synchronization, the clutch wheel 3 continues to move axially so that its second ring tooth 31 meshes with the first ring tooth 21 of the wheel 2. When the driving force is released, the tension spring 58 pulls the sliding sleeve 54 to reset through contraction force, causing the clutch wheel 3 to disengage and return to its initial position.

[0062] This solution converts rotational motion into linear displacement through a mechanical transmission mechanism between the cam disc 52 and the connecting plate 56. Combined with the elastic reset of the tension spring 58, this provides a buffering effect during the movement of the clutch wheel 3, preventing tooth wear caused by rigid impact. Through this technical solution, this application achieves precise control of the axial movement and reset of the clutch wheel 3. It provides a stable axial thrust during the synchronization phase of the second friction disc 4, maintains stable contact pressure during engagement through the mechanical self-locking characteristic of the cam disc 52, and quickly disengages during reset using the preload of the tension spring 58. This reduces impact vibration during power transmission and improves the operational reliability of the clutch device.

[0063] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0064] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A clutch device for a treadmill, comprising a central shaft (1), a wheel (2), a clutch wheel (3), a second friction disc (4), and a clutch drive assembly (5), characterized in that: The wheel (2) is rotatably mounted on the central shaft (1) to support the running belt; The clutch wheel (3) is coaxially arranged on the axial side of the wheel (2) and is used to connect the resistance device; The second friction disc (4) is coaxially nested inside the end of the clutch wheel (3) near the wheel (2) and is circumferentially linked with the clutch wheel (3); The clutch drive assembly (5) is configured to apply an axial driving force to the clutch wheel (3) in the engaged state, causing the clutch wheel (3) to drive the second friction disc (4) to move axially closer to or further away from the wheel (2) relative to the wheel (2); During the clutch engagement process, the second friction disc (4) first contacts and rubs against the wheel (2). The friction torque makes the rotation speed of the wheel (2), the second friction disc (4), and the clutch wheel (3) synchronize. After the rotation speed is matched, the clutch wheel (3) continues to move axially relative to the second friction disc (4) until it forms circumferential engagement with the wheel (2), thus completing the connection of the power transmission path.

2. The clutch device according to claim 1, characterized in that: A first friction disc (20) is fixedly connected to the end face of the wheel (2) facing the clutch wheel (3), and the edge of the first friction disc (20) is provided with a first annular tooth (21); The clutch wheel (3) has a first cavity (32) on the end face facing the wheel (2), and a second annular tooth (31) is provided on the inner wall of its edge; During clutch engagement, the second ring tooth (31) meshes with the first ring tooth (21) to complete the engagement of the power transmission path.

3. The clutch device according to claim 2, characterized in that: The second friction disk (4) has a third annular tooth (41) on its circumferential outer wall; The second friction disc (4) is embedded in the first cavity (32). The clutch wheel (3) and the second friction disc (4) are circumferentially linked by the circumferential clearance between the third ring tooth (41) and the second ring tooth (31), while allowing the two to move relative to each other axially.

4. The clutch device according to claim 3, characterized in that: Each tooth of the third annular tooth (41) has a guide boss (411) at the end near the wheel (2), and a constriction (412) is formed between adjacent guide bosses (411). During clutch engagement, the guide boss (411) guides the second annular tooth (31) so that the second annular tooth (31) aligns and engages with the first annular tooth (21).

5. The clutch device according to claim 1, characterized in that: The end face of the first friction disk (20) facing the second friction disk (4) is recessed to form a second cavity (22); The end of the second friction disk (4) is a conical platform (42), which can be embedded in the second cavity (22) and cooperate with the first friction disk (20).

6. The clutch device according to claim 5, characterized in that: The first friction disc (20) has a first wear-resistant ring (6) of rigid material fixed to its end face, which includes an annular plane (61) covering the end face and an annular conical surface (62) extending into the second cavity (22); The outer edge of the annular plane (61) is provided with a first annular guide tooth (63) that connects with the first annular tooth (21), and each first annular guide tooth (63) has a guide tooth tip; The conical platform (42) of the second friction disk (4) is engaged with the annular conical surface (62).

7. The clutch device according to claim 2, characterized in that: The clutch wheel (3) has a second wear-resistant ring (7) made of rigid material fixed to its end face. Its inner diameter edge is provided with a second annular guide tooth (71) that connects with the second annular tooth (31). Each second annular guide tooth (71) has a guide tooth tip.

8. The clutch device according to claim 1, characterized in that: A support spring (8) is sleeved on the central shaft (1) between the second friction disc (4) and the clutch wheel (3), and its two ends are directly or indirectly supported by the second friction disc (4) and the clutch wheel (3); During clutch engagement, the clutch wheel (3) pushes the second friction disc (4) to move axially through the support spring (8).

9. The clutch device according to claim 1, characterized in that: The second friction disk (4) has multiple sets of elastic push block assemblies (9) on its circumferential outer wall. Each set includes a movable push block (91) and a spring (92) between the push block (91) and the second friction disk (4). The inner wall of the first cavity (32) of the clutch wheel (3) is provided with a push groove (33); The push block (91) is embedded in the push groove (33) and engages with the inclined surface of the push groove (33); During clutch engagement, when the second friction disc (4) can no longer move axially, the push groove (33) of the clutch wheel (3) drives the push block (91) to radially compress the spring (92).

10. The clutch device according to claim 1, characterized in that: The clutch drive assembly (5) includes a clutch actuator disc (51), a cam disc (52), a fixed bushing (53), and a sliding bushing (54); The clutch actuator disk (51) and the cam disk (52) are coaxially mounted on the shaft (55) that passes through the fixed bushing (53); The protruding end of the cam disk (52) is connected to the sliding bushing (54) through the connecting plate (56), and the clutch wheel (3) is rotatably mounted on the sliding bushing (54) through the bearing (57). A tension spring (58) is provided between the sliding bushing (54) and the fixed bushing (53) to provide a reset tension.

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