A silent roller for a treadmill

Abstract

The utility model discloses a mute cylinder for treadmill belongs to treadmill technical field, including drive main shaft and two guide wheels, two guide wheels are fixed in the middle two sides of drive main shaft, and drive main shaft both ends pass through the guide wheel and are provided with bearing mounting end portion, and one bearing mounting end portion is provided with double bearing seat, and the double bearing seat is provided with the one -way bearing with key and the ball bearing in parallel, is provided with the keyway on drive main shaft, is provided with fixed key in the keyway, and the inner ring of one -way bearing with key is fixedly connected through fixed key, and the ball bearing is sleeved on drive main shaft, another bearing mounting end portion is provided with floating bearing seat, and the floating bearing seat is reserved with the alignment gap between drive main shaft, is provided with two different bearings in one end, can guarantee enough coaxial degree and stability, provides the main carrying capacity simultaneously, has optimized the noise and the friction heat problem of the noise and the friction heat problem brought by the original two end installation ball bearing.

Description

Technical Field

[0001] This utility model relates to the field of treadmill technology, and in particular to a silent roller for treadmills. Background Technology

[0002] As a popular indoor fitness device, the performance of the treadmill's core transmission component, the roller assembly, directly affects the smoothness of the equipment's operation, noise level, and user safety. Traditional treadmill rollers are typically supported on the running platform frame via a rotating shaft and bearing seats at both ends.

[0003] Chinese patent document CN209033648U discloses a novel treadmill roller, which is installed at both ends of the treadmill frame and used to wind the running belt. The roller is an integral solid slender shaft structure. The roller is pivotally connected to the treadmill frame by means of two bearings, which can reduce the height of the treadmill platform off the ground. The treadmill platform can be made thinner, taking up less space during packing and transportation, which can increase the container capacity. In addition, the platform is closer to the ground, and the treadmill runs more smoothly.

[0004] The bearings at both ends of the existing treadmill rollers are prone to misalignment after installation, which generates huge additional stress, causing the bearings to overheat and produce noise. Utility Model Content

[0005] To address the aforementioned problems, this utility model aims to solve the problems described above. One objective of this utility model is to provide a silent roller for treadmills that solves the above problems, resulting in very low noise during exercise, reduced bearing heat generation, and decreased bearing wear, thus extending bearing lifespan.

[0006] The solution adopted in this embodiment is as follows: a silent roller for a treadmill includes a drive spindle and two guide wheels. The two guide wheels are fixed to the middle sides of the drive spindle. Bearing mounting ends are provided at both ends of the drive spindle passing through the guide wheels. One of the bearing mounting ends is provided with a double bearing seat. A keyed one-way bearing and a ball bearing are arranged side by side in the double bearing seat. A keyway is provided on the drive spindle, and a fixing key is provided in the keyway. The inner ring of the keyed one-way bearing is fixedly connected to the drive spindle by the fixing key. The ball bearing is sleeved on the drive spindle. A floating bearing seat is provided on the other bearing mounting end. A self-aligning clearance is reserved between the floating bearing seat and the drive spindle.

[0007] A preferred technical solution is that the keyed one-way bearing is installed on the side close to the guide wheel, the double bearing housing is provided with a mounting groove in the middle, and both the keyed one-way bearing and the ball bearing are fixedly installed in the mounting groove, with the ball bearing located on the side away from the guide wheel.

[0008] A preferred technical solution is that a stepped bearing is provided in the floating bearing housing, the inner ring of the stepped bearing extends out to form a fixed step, the fixed step is fixedly connected to the drive spindle by screws, and the outer ring of the stepped bearing is clearance-fitted with the floating bearing housing.

[0009] A preferred technical solution is that the floating bearing housing has a mounting hole in the middle, the stepped bearing is installed in the mounting hole, the mounting hole has an oil guide groove on its side wall, a sealing cover is fixedly installed on the side of the floating bearing housing near the guide wheel, the sealing cover seals the end of the oil guide groove, and an oil injection pipe is provided on the outer wall of the floating bearing housing, the oil injection pipe is connected to the oil guide groove.

[0010] A preferred technical solution is that a limiting ring is provided at the outer end of the mounting groove, the limiting ring abuts against the outer ring of the ball bearing, the outer end of the mounting hole passes through, and the stepped bearing can slide along the axial direction of the mounting hole.

[0011] A preferred technical solution is that a retaining ring is provided on both sides of the double bearing housing, a retaining ring is provided on the drive spindle, the retaining ring is engaged in the retaining ring, the retaining ring abuts against the inner rings of the keyed one-way bearing and the ball bearing respectively, and a washer is provided between the retaining ring and the inner ring of the ball bearing.

[0012] A preferred technical solution is that a locking step is provided on the outer side of the guide wheel, the locking step is fixed to the drive spindle by screws, and a retaining spring is provided on both sides of the guide wheel, the retaining spring being engaged with the drive spindle.

[0013] Compared with the prior art, the silent roller for treadmills of this invention has the following technical advantages: This application discloses a silent roller for a treadmill, comprising a drive shaft and two guide wheels. The two guide wheels are fixed to both sides of the middle portion of the drive shaft. Bearing mounting ends are located at both ends of the drive shaft, passing through the guide wheels. One of the bearing mounting ends has a double bearing housing containing a keyed one-way bearing and a ball bearing arranged side-by-side. The drive shaft has a keyway with a fixing key. The inner ring of the keyed one-way bearing is fixedly connected to the drive shaft via the fixing key. The ball bearing is fitted onto the drive shaft. The other bearing mounting end has a floating bearing housing with a pre-existing self-aligning clearance between it and the drive shaft. Having two different bearings at one end ensures sufficient coaxiality and stability while providing the main load-bearing capacity, thus optimizing the noise and frictional heat problems associated with traditional two-end ball bearing installations.

[0014] Other features and advantages of the present invention will become clear when reading the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0016] Figure 1 This is a schematic diagram of the overall structure of the silent roller for a treadmill provided in a specific embodiment of this utility model; Figure 2 This is an exploded structural diagram of the double bearing seat portion provided in a specific embodiment of this utility model; Figure 3 This is an exploded structural diagram of the floating bearing seat provided in a specific embodiment of this utility model; In the picture: 1. Drive spindle; 2. Guide wheel; 3. Floating bearing housing; 4. Stepped bearing; 5. Double bearing housing; 6. Ball bearing; 7. Keyed one-way bearing; 8. Snap ring; 9. Washer; 11. Bearing mounting end; 12. Fixing key; 13. Snap ring; 21. Locking step; 31. Oil injection pipe; 32. Oil guide groove; 33. Sealing cover plate; 34. Mounting hole; 41. Fixing step; 51. Mounting groove; 52. Limiting ring. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0018] The following description, in conjunction with the accompanying drawings and embodiments, details the silent roller for the treadmill.

[0019] like Figure 1-3As shown, a silent roller for a treadmill includes a drive shaft 1 and two guide wheels 2. The two guide wheels 2 are fixed to both sides of the middle portion of the drive shaft 1. Bearing mounting ends 11 are provided at both ends of the drive shaft 1, passing through the guide wheels 2. The drive shaft 1 is made of high-strength alloy steel that has undergone quenching and tempering to provide sufficient rigidity to resist bending deformation and good wear resistance. The two guide wheels 2 are preferably made of lightweight, high-strength materials such as aluminum alloy or engineering plastics coated with a rubber layer, and their outer surfaces are typically textured to increase friction for driving and supporting the running belt.

[0020] One of the bearing mounting ends 11 is provided with a double bearing housing 5, in which a keyed one-way bearing 7 and a ball bearing 6 are arranged side by side. A through-type stepped mounting groove 51 is machined inside the double bearing housing 5. The two bearings, the keyed one-way bearing 7 and the deep groove ball bearing, which have different functions, are arranged side by side in the same bearing housing. A keyway is provided on the drive spindle 1, and a fixing key 12 is provided in the keyway. The inner ring of the keyed one-way bearing 7 is fixedly connected to the drive spindle 1 by the fixing key 12. The ball bearing 6 is sleeved on the drive spindle 1. Here, the ball bearing 6 is preferably a deep groove ball bearing, and its inner ring is sleeved on the spindle with a clearance fit or a slight transition fit. Its main function is not to transmit torque, but to provide a precise radial support point and axial positioning point for the spindle through a tight fit with the seat hole of the double bearing housing 5. It works in collaboration with the keyed one-way bearing 7, with the keyed one-way bearing 7 bearing the driving torque and reverse locking force, and the ball bearing 6 bearing the main radial load and providing axial positioning. This decoupling of functions allows each bearing to work under its best conditions, improving the overall load-bearing capacity and lifespan, and reducing noise caused by a single bearing bearing compound stress.

[0021] A floating bearing seat 3 is provided on the other bearing mounting end 11, and a self-aligning clearance is reserved between the floating bearing seat 3 and the drive spindle 1. The self-aligning clearance refers to two aspects: first, the outer ring of the stepped bearing 4 and the mounting hole 34 of the floating bearing seat 3 are in clearance fit; second, there is an axial clearance at the end of the bearing seat, without rigid limiting. This allows the drive spindle 1 to freely extend and retract axially at the floating end when the roller expands due to temperature rise during operation, avoiding bearing jamming or damage caused by thermal stress. Simultaneously, it automatically compensates for minor axial misalignment errors in the bearing seat holes at both ends of the drive spindle 1 caused by machining or installation, ensuring flexible roller rotation, effectively reducing vibration and operating noise, and improving product yield and reliability.

[0022] The keyed one-way bearing 7 is installed on the side near the guide wheel 2. The double bearing housing 5 has a mounting groove 51 in the middle, and both the keyed one-way bearing 7 and the ball bearing 6 are fixedly installed in the mounting groove 51, with the ball bearing 6 located on the side away from the guide wheel 2. This arrangement results in superior mechanical performance. Placing the keyed one-way bearing 7, which transmits driving torque, on the inner side brings it closer to the load application point, shortening the torque transmission path and improving transmission rigidity. Placing the ball bearing 6, mainly used for positioning, on the outer side creates a larger support span, which, together with the floating bearing housing 3 at the other end, better balances the bending moment of the roller, resulting in smoother operation. The stepped structure of the mounting groove 51 precisely positions and fixes the outer rings of the two bearings.

[0023] Based on the above, a stepped bearing 4 is provided in the floating bearing housing 3. The inner ring of the stepped bearing 4 extends to form a fixed step 41, which is fixedly connected to the drive spindle 1 by screws. Here, the stepped bearing 4 specifically refers to a one-way bearing or ball bearing 6 with a flange. Its inner ring flange has a through hole, which is directly fastened to the threaded hole on the end face of the drive spindle 1 by a hexagonal head screw. This achieves a rigid fit between the bearing inner ring and the drive spindle 1, providing extremely reliable axial fixation and completely preventing bearing movement on the shaft. Therefore, even when there is a gap between the stepped bearing 4 and the floating bearing housing 3, the stepped bearing 4 remains stable and does not move.

[0024] The outer ring of the stepped bearing 4 is clearance-fitted with the floating bearing housing 3. This clearance fit between the outer ring and the housing bore is crucial for achieving the floating function. It allows the entire outer ring assembly of the stepped bearing 4 to have both a small radial movement space within the floating bearing housing 3 for self-alignment and an axial movement space to accommodate thermal expansion. This is a key design feature for achieving low-stress, quiet operation.

[0025] The floating bearing housing 3 has a mounting hole 34 in its center, and the stepped bearing 4 is installed in the mounting hole 34. An oil guide groove 32 is provided on the side wall of the mounting hole 34. A sealing cover plate 33 is fixedly installed on the side of the floating bearing housing 3 near the guide wheel 2, sealing the end of the oil guide groove 32. An oil injection pipe 31 is provided on the outer wall of the floating bearing housing 3, communicating with the oil guide groove 32. The sealing cover plate 33 is fixed to the floating bearing housing 3 with screws, forming a seal with the end face of the mounting hole 34. Lithium-based grease or other lubricating grease can be periodically injected through an external grease nipple and oil injection pipe 31. The grease fills the oil guide groove 32 and slowly penetrates into the gap between the outer ring of the stepped bearing 4 and the housing bore, forming an oil film. This reduces friction and wear of the stepped bearing 4, ensuring the floating mating surfaces are always well lubricated, reducing frictional resistance and wear, and maintaining long-term self-aligning function. Simultaneously, the grease helps to dissipate heat and suppress vibration, further reducing operating noise. This significantly improves the service life of the floating bearing housing 3 and the stepped bearing 4, and reduces the frequency of maintenance.

[0026] A limiting ring 52 is provided at the outer end of the mounting groove 51, and the limiting ring 52 abuts against the outer ring of the ball bearing 6. The outer end of the mounting hole 34 extends through, and the stepped bearing 4 can slide along the axial direction of the mounting hole 34. The limiting ring 52 abuts against the outer ring of the ball bearing 6 from the outside axial direction. This ensures that the ball bearing 6 will not come out of the seat hole when subjected to axial tension from the running belt. The outer ring of the stepped bearing 4 can move slightly axially within the mounting hole 34. When the spindle expands due to heat, it pushes the entire stepped bearing 4 assembly outward; when it contracts due to cooling, it can move inward. This through-type design provides ample and unobstructed compensation space for thermal expansion, avoiding jamming and further overheating during use, resulting in smoother operation.

[0027] Preferably, retaining rings 8 are provided on both sides of the double bearing housing 5, and a retaining ring 13 is provided on the drive spindle 1. The retaining rings 8 are engaged in the retaining rings 13, and the retaining rings 8 abut against the inner rings of the keyed one-way bearing 7 and the ball bearing 6, respectively. A shim 9 is provided between the retaining rings 8 and the inner rings of the ball bearing 6. This is a refinement of the axial fixing scheme of the bearing inner rings on the spindle. The retaining ring 13 is an annular groove machined on the spindle. The retaining ring 8 is engaged in the groove, forming a defined axial constraint with the end face of the inner ring. The added shim 9 is used to fine-tune the axial clearance, ensuring that the bearing is firmly fixed without increasing rotational resistance and temperature rise due to excessive preload.

[0028] A locking step 21 is provided on the outer side of the guide wheel 2, and the locking step 21 is fixed to the drive spindle 1 by screws. The locking step 21 is integrally designed with the guide wheel 2 and is radially locked to the spindle by set screws. It provides a definite axial position for the guide wheel 2, preventing it from moving towards the end of the spindle. Snap rings 8 are provided on both sides of the guide wheel 2, and the snap rings 8 are engaged with the drive spindle 1. Snap ring 8 grooves are machined on the drive spindle 1 at positions corresponding to the two sides of the guide wheel 2 to embed the snap rings 8. These snap rings 8, together with the locking step 21, tightly clamp the guide wheel 2 in the middle from both sides, achieving bidirectional axial fixation of the guide wheel 2 on the spindle. This ensures that the guide wheel 2 will not axially move under high-speed operation and forward and reverse impacts, thereby guaranteeing the stability and centering of the treadmill belt.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes that element.

[0030] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. The utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A silent roller for a treadmill, comprising a drive shaft and two guide wheels, wherein the two guide wheels are fixed to both sides of the middle portion of the drive shaft, and bearing mounting ends are provided at both ends of the drive shaft passing through the guide wheels, characterized in that: One of the bearing mounting ends is provided with a double bearing housing, in which a keyed one-way bearing and a ball bearing are arranged side by side. The drive spindle is provided with a keyway, in which a fixing key is provided. The inner ring of the keyed one-way bearing is fixedly connected to the drive spindle by the fixing key, and the ball bearing is sleeved on the drive spindle. The other bearing mounting end is provided with a floating bearing housing, and a self-aligning clearance is reserved between the floating bearing housing and the drive spindle.

2. The silent roller for a treadmill as described in claim 1, characterized in that: The keyed one-way bearing is installed on the side close to the guide wheel. The double bearing housing has a mounting groove in the middle. Both the keyed one-way bearing and the ball bearing are fixedly installed in the mounting groove. The ball bearing is located on the side away from the guide wheel.

3. The silent roller for a treadmill as described in claim 2, characterized in that: The floating bearing housing is provided with a stepped bearing, the inner ring of the stepped bearing extends out to form a fixed step, the fixed step is fixedly connected to the drive spindle by screws, and the outer ring of the stepped bearing is clearance-fitted with the floating bearing housing.

4. The silent roller for a treadmill as described in claim 3, characterized in that: The floating bearing housing has a mounting hole in the middle, the stepped bearing is installed in the mounting hole, the mounting hole has an oil guide groove on the side wall, a sealing cover plate is fixedly installed on the side of the floating bearing housing near the guide wheel, the sealing cover plate seals the end of the oil guide groove, and an oil injection pipe is provided on the outer wall of the floating bearing housing, the oil injection pipe is connected to the oil guide groove.

5. The silent roller for a treadmill as described in claim 4, characterized in that: A limiting ring is provided at the outer end of the mounting groove, the limiting ring abuts against the outer ring of the ball bearing, the outer end of the mounting hole passes through, and the stepped bearing can slide along the axial direction of the mounting hole.

6. The silent roller for a treadmill as described in claim 2, characterized in that: Both sides of the dual bearing housing are provided with retaining rings, and the drive spindle is provided with a retaining ring. The retaining rings are engaged in the retaining rings. The retaining rings abut against the inner rings of the keyed one-way bearing and the ball bearing, respectively. A shim is provided between the retaining rings and the inner rings of the ball bearings.

7. The silent roller for a treadmill as described in claim 6, characterized in that: A locking step is provided on the outer side of the guide wheel, and the locking step is fixed to the drive spindle by screws. Snap rings are provided on both sides of the guide wheel and are snapped onto the drive spindle.

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