Holding type damper and rear derailleur

Abstract

The invention discloses an enclasping type damper and a rear derailleur. The enclasping type damper comprises a shell; the main shaft is rotationally connected with the shell around the axis of the main shaft, and a tensioning elastic piece is arranged between the main shaft and the shell; damping grease capable of generating a viscous damping effect is filled between the inner circumferential surface of the sleeve and the outer circumferential surface of the main shaft; the locking spring is provided with a fixed end and a free end and spirally extends to the free end from the fixed end in the axis direction of the main shaft, and when the sleeve rotates in the first rotating direction relative to the shell, the fixed end rotates along with the sleeve in the first rotating direction and forces the locking spring to expand in the radial direction; and the locking spring outwards supports the inner circumferential surface of the shell and prevents the fixed end and the sleeve from continuously rotating along the first rotating direction. The clasping type damper is obvious in one-way damping effect, rapid in damping response, capable of preventing chain falling, free of influence on normal gear shifting and speed changing of a rear derailleur, ingenious in structural design and low in requirement for later maintenance, machining and installation precision.

Description

Technical Field

[0001] The invention relates to the technical field of bicycles, in particular to a damper and a rear derailleur. Background Art

[0002] When a bicycle is bumping violently, due to the up and down inertia, the tensioner tends to move quickly towards the loose chain, which makes the chain fall off easily, which is particularly obvious on mountain bikes. To deal with this situation, dampers came into being, which can prevent the tensioner from jumping abnormally.

[0003] At present, some dampers use hydraulic damping, which has a relatively complex structure and requires high sealing performance of various parts of the damper, thus requiring high processing and installation accuracy. Some dampers use a combination of elastic parts and one-way bearings for damping. When dealing with fast and severe bumps, the damping spring needs to be impacted to a certain extent before it can react and implement reverse damping. The reverse damping effect is often proportional to the stroke of the damping spring, which delays the reaction and makes the chain drop prevention effect unclear. Although the one-way bearing can provide smooth and damped rotation conditions for free rotation and locked rotation respectively, the rollers, ratchets and other parts of the one-way bearing are prone to wear or pitting due to impact loads under frequent starting and stopping or high load conditions. Regular maintenance is required to ensure lubrication, which requires high professional operation of the driver. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a clamping damper, which has an obvious damping effect and has low requirements on subsequent maintenance, processing and installation accuracy.

[0005] The present invention also provides a rear derailleur having the above-mentioned clamping damper.

[0006] The clamping damper according to the embodiment of the first aspect of the present invention has opposite first and second rotation directions, and includes: a housing; a main shaft rotatably connected to the housing about its own axis, the main shaft can be actuated in the first rotation direction or the second rotation direction, a tension elastic member is arranged between the main shaft and the housing, and the tension elastic member is configured to apply a torque to the main shaft to rotate in the second rotation direction; a sleeve located in the housing and rotatably sleeved on the main shaft, and damping grease capable of generating a viscous damping effect is filled between the inner peripheral surface of the sleeve and the outer peripheral surface of the main shaft; a locking spring sleeved outside the sleeve and located between the sleeve and the housing, the locking spring has a fixed end and a free end and spirally extends from the fixed end around the axis direction of the main shaft to the free end, and the wire diameter of the locking spring is smaller than the distance between the outer peripheral surface of the sleeve and the inner peripheral surface of the housing; the fixed end is installed on the housing, the free end surrounds the outer peripheral surface of the sleeve, and the inner diameter of the locking spring in the natural state is equal to the outer peripheral surface diameter of the sleeve. When the sleeve rotates relative to the housing in the first rotation direction, the frictional force applied by the sleeve to the locking spring forces the free end to rotate in the first rotation direction and causes the locking spring to contract radially, so that the locking spring clamps the sleeve and hinders the sleeve from continuing to rotate in the first rotation direction; alternatively, the fixed end is installed on the sleeve, the free end abuts against the inner peripheral surface of the housing outwardly, and the outer diameter of the locking spring in the natural state is equal to the inner peripheral surface diameter of the housing. When the sleeve rotates relative to the housing in the first rotation direction, the fixed end follows the sleeve to rotate in the first rotation direction and forces the locking spring to expand radially, so that the locking spring tightly abuts against the inner peripheral surface of the housing outwardly and hinders the fixed end and the sleeve from continuing to rotate in the first rotation direction.

[0007] At least, it has the following beneficial effects: The main shaft of the clamping damper is configured as the swing center of the tension pulley. The main shaft is rotatably connected to the housing around its own axis. A tension elastic member is arranged between the main shaft and the housing. The tension elastic member can apply a torque to the main shaft to rotate in the second rotation direction, that is, apply a force to the tension pulley to tension the chain. In the normal running state of the bicycle, the tension elastic member is sufficient to meet the requirement of the tension pulley to tension the chain. A sleeve is rotatably sleeved outside the main shaft. A damping grease capable of generating a viscous damping effect is filled between the inner peripheral surface of the sleeve and the outer peripheral surface of the main shaft. A locking spring is arranged between the sleeve and the housing. The locking spring spirally extends from the fixed end around the axis direction of the main shaft to the free end. The fixed end is installed on the housing and the free end surrounds the outer peripheral surface of the sleeve, or the fixed end is installed on the sleeve and the free end outwardly abuts against the inner peripheral surface of the housing. When the bicycle encounters severe bumps, if the tension pulley has a tendency to move instantaneously and rapidly towards the direction of the slack chain, it is necessary to drive the main shaft to rotate rapidly in the first rotation direction. Due to the damping grease being subjected to rapid pulling impact and generating a large viscous damping effect, the main shaft can drive the sleeve to rotate in the first rotation direction through the damping grease. After experiencing a small rotation amplitude, the locking spring can quickly clamp the sleeve or outwardly tighten against the inner peripheral surface of the housing to prevent the sleeve from continuing to rotate in the first rotation direction, generating a large damping, thereby preventing the main shaft and the tension pulley from continuing to rotate and preventing the occurrence of chain dropping; if the tension pulley has a tendency to move instantaneously and rapidly towards the direction of the tensioned chain, it will drive the sleeve to rotate along the second rotation direction following the main shaft. The locking spring will gradually disengage from the outer peripheral surface of the sleeve or the inner peripheral surface of the housing, enabling the sleeve to rotate smoothly following the main shaft with very little resistance. And the tension of the chain itself will prevent the tension pulley from continuing to move, and the situation of chain dropping will not occur even more; when the rear derailleur performs normal shifting and speed change, the tension pulley and the main shaft rotate synchronously and uniformly in the first rotation direction or the second rotation direction, and the speed is much smaller than the situation when the bicycle encounters bumps. When the damping grease is subjected to a relatively slow pulling impact, the generated viscous damping effect is small, and the sleeve hardly rotates following the main shaft, and the resistance to the shifting operation is very small, which will not affect the normal shifting and speed change of the rear derailleur. The one-way damping effect of the clamping damper is obvious, and the damping response is rapid. The structural design is ingenious, and the requirements for later maintenance, processing and installation accuracy are low.

[0008] According to some embodiments of the present invention, an outwardly protruding diameter-expanding sleeve is fixedly installed on the main shaft at a position corresponding to the sleeve. The sleeve is rotatably sleeved on the diameter-expanding sleeve, and the damping grease is filled between the outer peripheral surface of the diameter-expanding sleeve and the inner peripheral surface of the sleeve.

[0009] According to some embodiments of the present invention, the sleeve is stepped and has a stepped end face and two inner peripheral surfaces with different inner diameters. A first sealing ring is provided between the outer peripheral surface of the diameter-expanding sleeve and one of the inner peripheral surfaces of the sleeve, and a second sealing ring is provided between the outer peripheral surface of the main shaft and the other inner peripheral surface of the sleeve. The first sealing ring, the stepped end face, the two inner peripheral surfaces of the sleeve, the second sealing ring, the outer peripheral surface of the main shaft, the end face of the diameter-expanding sleeve facing the stepped end face, and the outer peripheral surface of the diameter-expanding sleeve enclose an annular chamber, and the annular chamber is configured to be filled with damping grease.

[0010] According to some embodiments of the present invention, the diameter-expanding sleeve is provided with a first sealing groove along the circumferential direction, and the main shaft is provided with a second sealing groove along the circumferential direction. The first sealing ring and the second sealing ring are respectively constrained in the first sealing groove and the second sealing groove.

[0011] According to some embodiments of the present invention, the main shaft is provided with a clamping groove along the circumferential direction, and a snap ring is installed in the clamping groove. The snap ring and the end face of the diameter-expanding sleeve facing the stepped end face jointly constrain the axial position of the sleeve relative to the main shaft.

[0012] According to some embodiments of the present invention, the housing includes a rotary side wall, an end cover provided at one end of the rotary side wall, and a middle shell provided inside the rotary side wall. The main shaft is rotatably connected to the end cover, the locking spring is located between the rotary side wall and the sleeve, and the fixed end is installed on the middle shell or the sleeve.

[0013] According to some embodiments of the present invention, one end of the main shaft is axially abutted and stopped by the end cover, and the stepped end face is axially abutted and stopped by the middle shell. The end cover and the middle shell jointly constrain the axial position of the main shaft.

[0014] According to some embodiments of the present invention, one end of the main shaft away from the end cover is drivingly connected to a rotating cover. The rotating cover is inserted into the other end of the rotary side wall. The tensioning elastic member is a torsion spring, and the two torsion arms of the tensioning elastic member are respectively connected to the rotating cover and the middle shell.

[0015] According to some embodiments of the present invention, an external spline is provided at one end of the main shaft away from the end cover, and an internal spline is provided on the rotating cover. The main shaft and the rotating cover are spline-connected.

[0016] The derailleur according to the second aspect embodiment of the present invention includes a main body; a clamping damper according to the first aspect embodiment of the present invention above, and the housing is installed on the main body; a chain guiding assembly, including a guide plate and a guide wheel and a tensioning wheel rotatably installed on the guide plate, the guide plate is fixedly connected to the rotating cover, and the tensioning elastic member is configured to apply a force for tensioning the chain to the tensioning wheel.

[0017] It has at least the following beneficial effects: This derailleur has all the beneficial effects brought by the above clamping damper, and will not be repeated here.

[0018] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the drawings and embodiments, where: Figure 1 It is a schematic structural diagram of one perspective of the derailleur in the embodiment of the present invention; Figure 2 It is a schematic structural diagram of another perspective of the derailleur in the embodiment of the present invention; Figure 3 It is a cross-sectional view of the derailleur in the first embodiment of the present invention; Figure 4 It is an exploded view of the clamping damper in the first embodiment of the present invention; Figure 5 It is an exploded view of the main shaft and the sleeve in the embodiment of the present invention; Figure 6 It is a schematic diagram of the cooperation between the housing and the locking spring in the first embodiment of the present invention; Figure 7 It is a cross-sectional view of the derailleur in the second embodiment of the present invention; Figure 8 It is an exploded view of the clamping damper in the second embodiment of the present invention; Figure 9 It is a schematic diagram of the cooperation between the sleeve and the locking spring in the second embodiment of the present invention.

[0020] Reference numerals: main body 1, clamping damper 2, housing 21, rotating side wall 211, end cap 212, middle shell 213, main shaft 22, second sealing groove 221, clamping groove 222, snap ring 223, external spline 224, tensioning elastic member 23, sleeve 24, stepped end face 241, first inner peripheral surface 242, second inner peripheral surface 243, locking spring 25, fixed end 251, free end 252, diameter-expanding sleeve 26, first sealing groove 261, rotating cover 27, internal spline 271, first sealing ring 28, second sealing ring 29, annular chamber 210, chain guiding assembly 3, guide plate 31, guide wheel 32, tensioning wheel 33. Detailed implementation manners

[0021] In the description of the present invention, it should be understood that for the orientation description, such as the first rotation direction, the second rotation direction, the axial direction, the radial direction, etc., the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present invention.

[0022] In the description of the present invention, if the first and second are described only for the purpose of distinguishing technical features, it should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0023] In the description of the present invention, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection" should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0024] Refer to Figures 1 to 9 , the present invention discloses a clamping damper, including a housing 21, a main shaft 22, a tensioning elastic member 23, a sleeve 24 and a locking spring 25.

[0025] Refer to Figure 3 , Figure 4 , Figure 7 and Figure 8 , the main shaft 22 is rotationally connected to the housing 21 about its own axis, and the main shaft 22 can be actuated in the first rotation direction or the second rotation direction, wherein the first rotation direction and the second rotation direction are opposite. The tensioning elastic member 23 is arranged between the main shaft 22 and the housing 21. Refer to Figure 1 and Figure 2 , the tensioning elastic member 23 is configured to apply a torque to the main shaft 22 to rotate in the second rotation direction, that is, to apply a force to tension the chain to the tensioning wheel 33.

[0026] Refer to Figure 3 ,Figure 5 and Figure 7 The sleeve 24 is located in the housing 21 and is rotatably sleeved on the main shaft 22. The inner circumference of the sleeve 24 and the outer circumference of the main shaft 22 are filled with damping grease that can produce viscous damping effect. When the damping grease is subjected to a rapid pulling impact, it can produce a larger viscous damping effect. When it is subjected to a slower pulling impact, the viscous damping effect produced is smaller.

[0027] Reference Figure 3 , Figure 4 , Figure 7 and Figure 8 The shell 21 has a cylindrical inner circumference, the locking spring 25 is sleeved outside the sleeve 24 and is located between the outer circumference of the sleeve 24 and the inner circumference of the shell 21, the locking spring 25 has a fixed end 251 and a free end 252 and spirally extends from the fixed end 251 around the axial direction of the main shaft 22 to the free end 252, and the wire diameter of the locking spring 25 is smaller than the distance between the outer circumference of the sleeve 24 and the inner circumference of the shell 21.

[0028] Regarding the connection relationship of the locking spring 25 , there are two embodiments in the present invention.

[0029] In the first embodiment, referring to Figure 3 , Figure 4 and Figure 6 The fixed end 251 is installed on the shell body 21, and the free end 252 embraces the outer circumference of the sleeve 24. The inner diameter of the locking spring 25 in the natural state is equal to the outer circumference diameter of the sleeve 24. It should be noted that, considering the actual manufacturing accuracy and consistency of the locking spring 25, in the natural state, the inner diameter of at least part of the spiral section in the locking spring 25 does not exceed the outer circumference diameter of the sleeve 24, so as to maintain the embracing pressure applied by the locking spring 25 to the outer circumference of the sleeve 24.

[0030] When the sleeve 24 rotates relative to the housing 21 in the first rotation direction, the friction effect exerted by the sleeve 24 on the locking spring 25 forces the free end 252 to rotate slightly in the first rotation direction and causes the locking spring 25 to contract radially. The reaction is very rapid, so that the locking spring 25 holds the sleeve 24 tightly. The pressure between the locking spring 25 and the sleeve 24 increases significantly, and the locking spring 25 is hindered by the sleeve 24 in the radial direction and cannot further contract or rotate. The friction force exerted by the locking spring 25 on the sleeve 24 also increases significantly, thereby preventing the sleeve 24 from continuing to rotate in the first rotation direction. When the sleeve 24 rotates relative to the housing 21 in the second rotation direction, the frictional force exerted by the sleeve 24 on the locking spring 25 forces the free end 252 to rotate slightly in the second rotation direction and causes the locking spring 25 to expand radially. The reaction is very rapid, so that the locking spring 25 gradually releases the outer peripheral surface of the sleeve 24. Since the wire diameter of the locking spring 25 is smaller than the distance between the outer peripheral surface of the sleeve 24 and the inner peripheral surface of the housing 21, it is ensured that the locking spring 25 has sufficient radial expansion space, and the pressure between the locking spring 25 and the sleeve 24 is significantly reduced, enabling the sleeve 24 to rotate smoothly with very little resistance.

[0031] In the second embodiment, referring to Figure 7 , Figure 8 and Figure 9 , the fixed end 251 is installed on the sleeve 24, and the free end 252 abuts against the inner peripheral surface of the housing 21 outwardly. The outer diameter of the locking spring 25 in the natural state is equal to the inner peripheral surface diameter of the housing 21. It should be noted that considering the actual manufacturing accuracy and consistency of the locking spring 25, in the natural state, the outer diameter of at least some spiral segments of the locking spring 25 is not less than the inner peripheral surface diameter of the housing 21 to maintain the outward support pressure exerted by the locking spring 25 on the inner peripheral surface of the housing 21.

[0032] When the sleeve 24 rotates relative to the housing 21 in the first rotation direction, the fixed end 251 follows the sleeve 24 to rotate slightly in the first rotation direction and forces the locking spring 25 to expand radially. The reaction is very rapid, so that the locking spring 25 presses tightly against the inner peripheral surface of the housing 21 outwardly. The pressure between the locking spring 25 and the inner peripheral surface of the housing 21 is significantly increased, and the locking spring 25 is blocked by the inner peripheral surface of the housing 21 in the radial direction and cannot expand or rotate further. Since the fixed end 251 is fixedly connected to the sleeve, the fixed end 251 also blocks the sleeve 24 from continuing to rotate in the first rotation direction; When the sleeve 24 rotates relative to the housing 21 in the second rotation direction, the fixed end 251 follows the sleeve 24 to rotate slightly in the second rotation direction and forces the locking spring 25 to contract radially. The reaction is very rapid, so that the locking spring 25 releases the inner peripheral surface of the housing 21 inwardly. Since the wire diameter of the locking spring 25 is smaller than the distance between the outer peripheral surface of the sleeve 24 and the inner peripheral surface of the housing 21, it is ensured that the locking spring 25 has sufficient radial contraction space, and the pressure between the locking spring 25 and the housing 21 is significantly reduced, enabling the locking spring 25 to rotate smoothly with the sleeve 24 with very little resistance.

[0033] In the first embodiment and the second embodiment, as long as the sleeve 24 rotates relative to the housing 21 by a very small angle in the first rotation direction, the locking spring 25 can respond rapidly to achieve the reverse damping effect, while when the sleeve 24 rotates relative to the housing 21 in the second rotation direction, the locking spring 25 offers very little resistance to the sleeve 24, thus achieving the effect of one-way damping.

[0034] Referring to Figure 1 、 Figure 2 and Figure 3 , the clamping damper 2 is applied to the derailleur. The main shaft 22 of the clamping damper 2 is configured as the swing center of the tension pulley 33. The tension elastic member 23 can apply a torque to rotate the main shaft 22 in the second rotation direction. In the normal running state of the bicycle, the tension elastic member 23 is sufficient to meet the requirement of the tension pulley 33 for tensioning the chain.

[0035] When the bicycle encounters severe bumps, if the tension pulley 33 has a tendency to move instantaneously and rapidly towards the direction of the slack chain, it is necessary to drive the main shaft 22 to rotate rapidly in the first rotation direction. Since the damping grease is subjected to rapid pulling impact and generates a large viscous damping effect, the main shaft 22 can drive the sleeve 24 to rotate in the first rotation direction through the damping grease. After experiencing a small rotation amplitude, the locking spring 25 can quickly clamp the sleeve 24 or outwardly press against the inner peripheral surface of the housing 21 to prevent the sleeve 24 from continuing to rotate in the first rotation direction, generating a large damping, thereby preventing the main shaft 22 and the tension pulley 33 from continuing to rotate and preventing the occurrence of chain dropping. If the tension pulley 33 has a tendency to move instantaneously and rapidly towards the direction of the tensioned chain, it will drive the sleeve 24 to rotate along the second rotation direction following the main shaft 22. The locking spring 25 will gradually disengage from the outer peripheral surface of the sleeve 24 or the inner peripheral surface of the housing 21, enabling the sleeve 24 to rotate smoothly following the main shaft 22 with very little resistance. Moreover, the tension of the chain itself will prevent the tension pulley 33 from continuing to move, and the situation of chain dropping will never occur. When the derailleur performs normal shifting and speed changing, the tension pulley 33 and the main shaft 22 rotate synchronously and uniformly in the first rotation direction or the second rotation direction, and the speed is much smaller than the situation when the bicycle encounters bumps. When the damping grease is subjected to a relatively slow pulling impact, the generated viscous damping effect is small, and the sleeve 24 hardly rotates following the main shaft 22, with very little resistance to the shifting operation, which will not affect the normal shifting and speed changing of the derailleur. The one-way damping effect of the clamping damper 2 is obvious, the damping response is rapid, the structural design is ingenious, and the requirements for later maintenance, processing and installation accuracy are low.

[0036] In some embodiments of the present invention, referring to Figure 3 、 Figure 5 and Figure 7, a diameter-expanding sleeve 26 protruding outward is fixedly installed on the main shaft 22 at a position corresponding to the sleeve 24. The sleeve 24 is rotatably sleeved on the diameter-expanding sleeve 26. Between the outer peripheral surface of the diameter-expanding sleeve 26 and the inner peripheral surface of the sleeve 24, damping grease is filled. The diameter of the diameter-expanding sleeve 26 relative to the main shaft 22 is larger, effectively increasing the contact area with the damping grease and enabling the damping grease to generate a greater viscous damping effect. It can be understood that the diameter-expanding sleeve 26 can be integrally formed with the main shaft 22 through a rubber-coated injection molding process or fixedly inserted into the main shaft 22.

[0037] Referring to Figure 3 , Figure 5 and Figure 7 , in some embodiments, the sleeve 24 is stepped and has a stepped end face 241 and two inner peripheral surfaces with different inner diameters. The two inner peripheral surfaces with different inner diameters are respectively a first inner peripheral surface 242 and a second inner peripheral surface 243. The outer ring of the stepped end face 241 is connected to the first inner peripheral surface 242, and the inner ring is connected to the second inner peripheral surface 243. A first sealing ring 28 is provided between the outer peripheral surface of the diameter-expanding sleeve 26 and the first inner peripheral surface 242, and a second sealing ring 29 is provided between the outer peripheral surface of the main shaft 22 and the second inner peripheral surface 243.

[0038] Among them, the first sealing ring 28, the first inner peripheral surface 242, the stepped end face 241, the second inner peripheral surface 243, the second sealing ring 29, the outer peripheral surface of the main shaft 22, the end face of the diameter-expanding sleeve 26 facing the stepped end face 241, and the outer peripheral surface of the diameter-expanding sleeve 26 enclose an annular chamber 210. The annular chamber 210 is configured to be filled with damping grease to further increase the contact area of the damping grease with the main shaft 22, the sleeve 24, and the diameter-expanding sleeve 26.

[0039] It can be understood that there is good sealing between the diameter-expanding sleeve 26 and the main shaft 22, and the damping grease will not penetrate between the diameter-expanding sleeve 26 and the main shaft 22.

[0040] In some embodiments, referring to Figure 3 , Figure 5 and Figure 7 , the diameter-expanding sleeve 26 is provided with a first sealing groove 261 along the circumferential direction, and the main shaft 22 is provided with a second sealing groove 221 along the circumferential direction. The first sealing ring 28 and the second sealing ring 29 are respectively constrained in the first sealing groove 261 and the second sealing groove 221, which can effectively prevent the first sealing ring 28 and the second sealing ring 29 from slipping and shifting, and realize the sealing function of the annular chamber 210.

[0041] Referring to Figure 4 and Figure 9 , in some embodiments, the main shaft 22 is provided with a clamping groove 222 along the circumferential direction, and a snap ring 223 is installed in the clamping groove 222. Further referring to Figure 3 and Figure 7, the end faces of the snap ring 223 and the diameter-expanding sleeve 26 facing the stepped end face 241 jointly restrict the axial position of the sleeve 24 relative to the main shaft 22, facilitating the pre-assembly connection between the sleeve 24, the diameter-expanding sleeve 26 and the main shaft 22, and then the whole is installed into the housing 21.

[0042] It should be noted that there is a gap capable of filling damping grease between the stepped end face 241 and the end face of the diameter-expanding sleeve 26 facing the stepped end face 241, which forms a part of the annular chamber 210.

[0043] Refer to Figure 3 and Figure 7 , the housing 21 may specifically include a rotating side wall 211, an end cover 212 provided at one end of the rotating side wall 211, and a middle shell 213 provided inside the rotating side wall 211. The main shaft 22 is rotatably connected to the end cover 212. The inner peripheral surface of the rotating side wall 211 is cylindrical. The locking spring 25 is located between the rotating side wall 211 and the sleeve 24.

[0044] Among them, in the first embodiment, the fixed end 251 of the locking spring 25 is installed on the middle shell 213; in the second embodiment, the free end 252 of the locking spring 25 abuts against the inner peripheral surface of the rotating side wall 211 outwardly.

[0045] Refer to Figure 3 and Figure 7 , one end of the main shaft 22 is axially abutted and stopped by the end cover 212, and the stepped end face 241 of the sleeve 24 is axially abutted and stopped by the middle shell 213. Since the end faces of the snap ring 223 and the diameter-expanding sleeve 26 facing the stepped end face 241 jointly restrict the axial position of the sleeve 24 relative to the main shaft 22, the end cover 212 and the middle shell 213 jointly restrict the axial position of the main shaft 22. By reasonably designing the distance between the end cover 212 and the middle shell 213, it can be ensured that there is enough clearance between the stepped end face 241 and the end face of the diameter-expanding sleeve 26 facing the stepped end face 241.

[0046] In some embodiments of the present invention, refer to Figure 3 , Figure 4 , Figure 7 and Figure 8 , one end of the main shaft 22 far from the end cover 212 is drivingly connected to the rotating cover 27. The rotating cover 27 is inserted into the other end of the rotating side wall 211 to realize the airtightness of the housing 21. The tensioning elastic member 23 is a torsion spring. The two torsion arms of the tensioning elastic member 23 are respectively connected to the rotating cover 27 and the middle shell 213. The tensioning elastic member 23 applies a torque for rotating the rotating cover 27 in the second rotation direction to apply a force for tensioning the chain to the tensioning wheel 33.

[0047] Refer to Figure 2The rotating cover 27 is configured as an intermediate piece for transmission between the tensioning wheel 33 and the main shaft 22 , and receives the swinging power transmitted from the tensioning wheel 33 to the main shaft 22 , and the damping force transmitted from the main shaft 22 to the tensioning wheel 33 .

[0048] Reference Figure 4 and Figure 8 In some embodiments, an external spline 224 is provided on the end of the main shaft 22 away from the end cover 212, and an internal spline 271 is provided on the rotating cover 27. The main shaft 22 and the rotating cover 27 are spline-connected. The spline connection structure can facilitate the insertion and assembly between the main shaft 22 and the rotating cover 27, and then the rotating cover 27 is fastened to the main shaft 22 by fasteners to achieve axial locking constraints between the two.

[0049] Reference Figures 1 to 9 The present invention discloses a rear derailleur, comprising a main body 1, a clamping damper 2 of the above-mentioned embodiment and a chain guide assembly 3.

[0050] Among them, the shell 21 is installed on the main body 1, the chain guide assembly 3 includes a guide plate 31 and a guide wheel 32 and a tensioning wheel 33 rotatably installed on the guide plate 31, the guide plate 31 is fixedly connected to the rotating cover 27, and the tensioning elastic member 23 is configured to apply a torque rotating along the second rotation direction to the main shaft 22, and the main shaft 22 is the swing center of the tensioning wheel 33, that is, the tensioning elastic member 23 is configured to apply a force to tension the chain to the tensioning wheel 33.

[0051] The rear derailleur has obvious unidirectional damping effect and rapid damping response, can effectively prevent the chain from falling off, and will not affect the normal gear shifting operation of the bicycle. The structural design is ingenious and has low requirements on the later maintenance, processing and installation accuracy.

[0052] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] Of course, the present invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. Clamping damper, characterized in that, Having opposite first and second rotation directions, comprising: case; A main shaft, rotatably connected to the housing about its own axis, the main shaft can be actuated in a first rotation direction or a second rotation direction, a tensioning elastic member is provided between the main shaft and the housing, and the tensioning elastic member is configured to apply a torque to the main shaft to rotate in the second rotation direction; A sleeve is located in the housing and is rotatably sleeved on the main shaft, and a damping grease capable of generating a viscous damping effect is filled between the inner circumference of the sleeve and the outer circumference of the main shaft; A locking spring, which is sleeved outside the sleeve and located between the sleeve and the housing, wherein the locking spring has a fixed end and a free end and spirally extends from the fixed end around the axis direction of the main shaft to the free end, and the wire diameter of the locking spring is smaller than the distance between the outer circumference of the sleeve and the inner circumference of the housing; The fixed end is mounted on the housing, the free end embraces the outer circumference of the sleeve, the inner diameter of the locking spring in a natural state is equal to the outer circumference diameter of the sleeve, and when the sleeve rotates relative to the housing in a first rotation direction, the friction effect exerted by the sleeve on the locking spring forces the free end to rotate in the first rotation direction and causes the locking spring to contract radially, so that the locking spring embraces the sleeve and prevents the sleeve from continuing to rotate in the first rotation direction; Alternatively, the fixed end is mounted on the sleeve, the free end is supported outwardly against the inner circumferential surface of the shell, the outer diameter of the locking spring in a natural state is equal to the inner circumferential surface diameter of the shell, and when the sleeve rotates relative to the shell in a first rotational direction, the fixed end rotates along the first rotational direction with the sleeve and forces the locking spring to expand radially, so that the locking spring is supported outwardly against the inner circumferential surface of the shell and prevents the fixed end and the sleeve from continuing to rotate in the first rotational direction.

2. The clamping damper according to claim 1, wherein The main shaft is fixedly provided with an outwardly protruding diameter expansion sleeve at a position corresponding to the sleeve, the sleeve is rotatably sleeved on the diameter expansion sleeve, and the damping grease is filled between the outer circumference of the diameter expansion sleeve and the inner circumference of the sleeve.

3. The clamping damper according to claim 2, wherein, The sleeve is stepped and has a stepped end face and two inner circumferential surfaces with different inner diameters. A first sealing ring is arranged between the outer circumferential surface of the expansion sleeve and one of the inner circumferential surfaces of the sleeve, and a second sealing ring is arranged between the outer circumferential surface of the main shaft and the other inner circumferential surface of the sleeve. The first sealing ring, the stepped end face, the two inner circumferential surfaces of the sleeve, the second sealing ring, the outer circumferential surface of the main shaft, the end face of the expansion sleeve facing the stepped end face, and the outer circumferential surface of the expansion sleeve together form an annular chamber, and the annular chamber is configured to be filled with the damping grease.

4. The clamping damper according to claim 3, characterized in that The expansion sleeve is provided with a first sealing groove along the circumferential direction, the main shaft is provided with a second sealing groove along the circumferential direction, and the first sealing ring and the second sealing ring are respectively constrained in the first sealing groove and the second sealing groove.

5. The clamping damper according to claim 3, wherein The main shaft is circumferentially provided with a clamping groove, a snap ring is installed in the clamping groove, and the end faces of the snap ring and the diameter-expanding sleeve facing the stepped end face jointly restrict the axial position of the sleeve relative to the main shaft.

6. The clamping damper according to claim 5, characterized in that, The housing includes a rotary side wall, an end cover provided at one end of the rotary side wall, and a middle housing provided inside the rotary side wall. The main shaft is rotatably connected to the end cover. The locking spring is located between the rotary side wall and the sleeve, and the fixed end is installed on the middle housing or the sleeve.

7. The clamping damper according to claim 6, wherein One end of the main shaft is axially abutted and stopped by the end cover, and the stepped end face is axially abutted and stopped by the middle housing. The end cover and the middle housing jointly restrict the axial position of the main shaft.

8. The clamping damper according to claim 7, wherein, One end of the main shaft away from the end cover is drivingly connected to a rotary cover. The rotary cover is inserted into the other end of the rotary side wall. The tensioning elastic member is a torsion spring, and the two torsion arms of the tensioning elastic member are respectively connected to the rotary cover and the middle housing.

9. The clamping damper according to claim 8, wherein, One end of the main shaft away from the end cover is provided with an external spline, the rotary cover is provided with an internal spline, and the main shaft is spline-connected to the rotary cover.

10. Rear derailleur, characterized in that, Comprising: A main body; The clamping damper according to claim 8 or 9, wherein the housing is installed on the main body; A chain guiding assembly, including a guide plate, a guide wheel and a tensioning wheel rotatably installed on the guide plate. The guide plate is fixedly connected to the rotary cover, and the tensioning elastic member is configured to apply a force for tensioning the chain to the tensioning wheel.

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