Hydraulic damper and rear derailleur

Abstract

The invention discloses a hydraulic damper and a rear derailleur with the hydraulic damper, and the hydraulic damper comprises a shell with a closed inner cavity inside; one end of the main shaft extends into the closed inner cavity and is provided with a damping partition plate capable of dividing the closed inner cavity into a pressure bearing chamber and a pressure relief chamber, and a flowing gap allowing fluid to circulate is formed between the damping partition plate and the shell; the head end and the tail end of the fluid channel communicate with the pressure relief chamber and the pressure bearing chamber correspondingly, a one-way valve is arranged in the fluid channel and comprises a valve element and a spring, and the spring extends in the horizontal direction and is arranged between the valve element and the shell; when the main shaft is actuated in the first rotation direction, fluid in the pressure bearing chamber flows to the pressure relief chamber through the flowing gap, and the damping partition plate bears rotation resistance applied by the fluid in the second rotation direction. The hydraulic damper is very obvious in damping effect, the situation of chain falling is effectively reduced, the requirement for machining and assembling precision of the damping partition plate and the shell is low, and the situation of chain falling caused by reverse opening of the one-way valve is prevented.

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, dampers mostly use spring 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 effect of preventing the chain from falling off unclear. Some also use hydraulic damping. Some hydraulic dampers have a more complex structure and require high sealing performance of various parts of the damper, which in turn requires high processing and assembly precision. In addition, there is the possibility that the parts of the damper fail abnormally under overweight or weightless conditions caused by severe bumps, and the chain is also prone to falling off. 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 damper with obvious damping effect and low sealing performance requirements.

[0005] The present invention also provides a rear derailleur having the damper.

[0006] The hydraulic damper according to the first embodiment of the present invention has a horizontal direction and opposite first and second rotation directions, including: a shell having a sealed inner cavity inside, the sealed inner cavity being configured to contain a fluid; a main shaft, which is connected to the shell by rotation around its own axis, the main shaft can be actuated along the first rotation direction or the second rotation direction, one end of the main shaft extends into the sealed inner cavity and is equipped with a damping baffle that can separate the sealed inner cavity into a pressure-bearing chamber and a pressure-releasing chamber, a flow gap for the fluid to flow is formed between the damping baffle and the shell; a fluid channel is arranged on the shell, the head and tail ends of the fluid channel are respectively connected to the pressure chamber and the pressure chamber. The pressure relief chamber and the pressure receiving chamber are connected, and a one-way valve is arranged in the fluid passage. The one-way valve includes a valve core and a spring. The spring extends in a horizontal direction and is arranged between the valve core and the housing. The spring acts on the valve core and applies an elastic force to the valve core in the direction of blocking the fluid passage. The valve core can pass through the fluid passage under the action of a positive pressure difference between the pressure relief chamber and the pressure receiving chamber. When the main shaft is actuated along a first rotation direction, the one-way valve remains in a closed state, and the fluid in the pressure receiving chamber flows to the pressure relief chamber through the flow gap, and the damping partition withstands the rotational resistance applied by the fluid along the second rotation direction.

[0007] At least the following beneficial effects are provided: when the main shaft is actuated along the second rotation direction, the damping diaphragm rotates accordingly, thereby squeezing the fluid in the pressure relief chamber, and the valve core opens the one-way valve under the action of the positive pressure difference between the pressure relief chamber and the pressure-bearing chamber, and connects the fluid channel, so that the fluid in the pressure relief chamber can easily flow to the pressure-bearing chamber through the fluid channel, and the resistance is very small, and the rotation of the main shaft along the second rotation direction is reasonably converted into the movement of the tensioning wheel along the direction of the tensioning chain, and the chain will not fall off; when the main shaft is actuated along the first rotation direction, the damping diaphragm rotates accordingly, thereby squeezing the fluid in the pressure-bearing chamber. Since the one-way valve remains in a closed state, the fluid in the pressure-bearing chamber can only flow to the pressure relief chamber through the flow gap. Since the cross-sectional area of ​​the flow gap is relatively small, the instantaneous flow rate is small, and the fluid in the rapid extrusion impulse In the event of impact, the damping diaphragm is subjected to the rotational resistance along the second rotational direction applied by the fluid, that is, the resistance formed by the positive pressure difference between the pressure-bearing chamber and the pressure-relief chamber on the damping diaphragm, which prevents the damping diaphragm from rotating significantly. The damping effect is very obvious, and the rotation of the main shaft along the first rotational direction is reasonably converted into the movement of the tensioning wheel along the direction of loosening the chain, which effectively reduces the chain falling. Since there is no need for strict sealing between the damping diaphragm and the shell, the processing and assembly accuracy requirements of the damping diaphragm and the shell are low; and the spring of the one-way valve extends in the horizontal direction, parallel to the ground. Even if the bump causes the valve core to be overweight or weightless, the spring will not be abnormally deformed in the horizontal direction, ensuring that the valve core will not shift its position, thereby preventing the chain falling caused by the reverse opening of the one-way valve.

[0008] According to some embodiments of the present invention, the one-way valve also includes a valve port constituting a section of the fluid channel, the valve port gradually expands in a direction away from the pressure relief chamber, the valve core is spherical, and the valve core can be pressed against the valve port under the elastic force of the spring or move away from the valve port under the action of the positive pressure difference between the pressure relief chamber and the pressure chamber.

[0009] According to some embodiments of the present invention, the shell includes an end cover, a middle shell rotatably connected to the main shaft, and a rotating side wall arranged between the middle shell and the end cover, the middle shell, the rotating side wall and the end cover enclose the closed inner cavity, the rotating side wall is provided with a partition plate extending toward the main shaft, the partition plate extends from the middle shell to the end cover and abuts against the damping partition, the partition plate and the damping partition jointly separate the closed inner cavity into the pressure-bearing chamber and the pressure-relieving chamber.

[0010] According to some embodiments of the present invention, the flow gap includes a first flow gap formed between an end of the damping baffle away from the main shaft and the rotating side wall.

[0011] According to some embodiments of the present invention, the flow gap includes a second flow gap, the damping baffle includes a sleeve portion fixedly mounted on the main shaft and a blade portion extending radially from the sleeve portion toward the rotating side wall, and the second flow gap is formed between the outer side wall of the sleeve portion and the partition plate.

[0012] According to some embodiments of the present invention, the flow gap comprises a third flow gap formed between the damping diaphragm and the end cover.

[0013] According to some embodiments of the present invention, the flow gap includes a fourth flow gap formed between the damping diaphragm and the middle shell.

[0014] According to some embodiments of the present invention, the fluid channel is embedded in the middle shell, the head end of the fluid channel is connected to the pressure relief chamber through the channel inlet, the tail end of the fluid channel is connected to the pressure chamber through the channel outlet, and the rotation range of the damping baffle does not cover the channel inlet and the channel outlet.

[0015] According to some embodiments of the present invention, a tensioning elastic member is disposed between the housing and the main shaft, and the tensioning elastic member is configured to apply a torque to the main shaft to rotate along the second rotation direction.

[0016] The rear derailleur according to the second aspect of the present invention comprises: a main body; a hydraulic damper according to the first aspect of the present invention, wherein the shell is mounted on the main body; a chain guide assembly comprises a guide plate and a guide wheel and a tension wheel rotatably mounted on the guide plate, wherein the guide plate is fixedly connected to the other end of the main shaft, and the tensioning elastic member is configured to apply a force to the tensioning wheel to tension the chain.

[0017] At least the following beneficial effects are provided: under normal conditions, the tensioning elastic member is sufficient to meet the needs of the tensioning wheel to tension the chain. When the bicycle is bumpy, if the tensioning wheel is expected to move in the direction of loosening the chain, it is necessary to drive the guide plate and the main shaft to rotate in the first rotation direction, and the damping diaphragm follows the rotation, thereby squeezing the fluid in the pressure chamber. Since the one-way valve remains in a closed state, the fluid in the pressure chamber can only flow to the pressure relief chamber through the flow gap. Since the cross-sectional area of ​​the flow gap is relatively small and the instantaneous flow rate is small, in the case of rapid extrusion impact, the damping diaphragm withstands the pressure exerted by the fluid in the second rotation direction. The rotational resistance in the direction refers to the resistance formed by the positive pressure difference between the pressure chamber and the pressure relief chamber on the damping baffle, which prevents the damping baffle and the guide plate from rotating significantly. The damping effect is very obvious, which effectively reduces the chain falling. Since there is no need for strict sealing between the damping baffle and the shell, the processing and assembly precision requirements of the damping baffle and the shell are low; and the spring of the one-way valve extends in the horizontal direction, parallel to the ground. Even if the bump causes the valve core to be overweight or weightless, the spring will not be abnormally deformed in the horizontal direction, ensuring that the valve core will not shift its position, preventing the chain falling caused by the reverse opening of the one-way valve.

[0018] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 It is a schematic structural diagram of a rear derailleur in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the structure after the end cover is hidden; Figure 3 for Figure 2 Schematic diagram of the local structure; Figure 4 A schematic diagram of the structure of a hydraulic damper in an embodiment of the present invention; Figure 5 for Figure 4 AA rotated section view; Figure 6 for Figure 4 BB cutaway view.

[0020] Figure numbers: main body 10, hydraulic damper 20, shell 21, closed inner cavity 21a, pressure chamber 21b, pressure relief chamber 21c, end cover 211, middle shell 212, middle shell base 2121, middle shell pressure cover 2122, rotating side wall 213, partition plate 214, main shaft 22, damping partition 23, sleeve part 231, blade part 232, flow gap 24, first flow gap 241, second flow gap 242, third flow gap 243, fourth flow gap 244, fluid channel 25, channel inlet 251, channel outlet 252, one-way valve 26, valve core 261, spring 262, valve port 263, tensioning elastic member 27, compensation chamber 28, through hole 281, liquid capsule membrane 282, chain guide assembly 30, guide plate 31, guide wheel 32, tensioning wheel 33. DETAILED DESCRIPTION

[0021] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0022] In the description of the present invention, it is necessary to understand that the descriptions involving orientations, such as horizontal, inside, outside, up, down, left and right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are 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, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, if there is a description of first, second, third and fourth, it is only for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0024] In the description of the present invention, unless otherwise clearly defined, words such as setting, installing, connecting, rotating, turning, connecting, penetrating, and blocking should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above words in the present invention based on the specific content of the technical solution.

[0025] Reference Figures 1 to 6 The present invention discloses a hydraulic damper having a horizontal direction and opposite first and second rotation directions. The hydraulic damper 20 includes a housing 21, a main shaft 22, a damping baffle 23, a flow gap 24, a fluid channel 25 and a one-way valve 26.

[0026] Among them, refer to Figure 3 and Figure 5 The shell 21 has a closed inner cavity 21a inside, and the closed inner cavity 21a is configured to accommodate fluid. The main shaft 22 rotates around its own axis to connect to the shell 21. The main shaft 22 can be actuated along the first rotation direction or the second rotation direction. One end of the main shaft 22 extends into the closed inner cavity 21a and is installed with a damping baffle 23. The damping baffle 23 can separate the closed inner cavity 21a into a pressure-bearing chamber 21b and a pressure-releasing chamber 21c. A flow gap 24 for fluid circulation is formed between the damping baffle 23 and the shell 21.

[0027] Reference Figure 6 The fluid channel 25 is arranged on the housing 21 , and the head and tail ends of the fluid channel 25 are respectively connected to the pressure relief chamber 21 c and the pressure bearing chamber 21 b , and a one-way valve 26 is arranged in the fluid channel 25 .

[0028] The one-way valve 26 specifically includes a valve core 261 and a spring 262. The spring 262 extends in the horizontal direction and is arranged between the valve core 261 and the housing 21. The spring 262 acts on the valve core 261 and applies an elastic force to the valve core 261 in the direction of blocking the fluid channel 25, so that the one-way valve 26 can remain in a normally closed state; the valve core 261 can penetrate the fluid channel 25 under the action of the positive pressure difference between the pressure relief chamber 21c and the pressure chamber 21b to open the one-way valve 26.

[0029] It should be noted that the cross-sectional area of ​​the flow gap 24 is smaller than the cross-sectional area of ​​the fluid channel 25. It can even be said that the cross-sectional area of ​​the flow gap 24 is much smaller than the cross-sectional area of ​​the fluid channel 25, ensuring that the instantaneous flow rate of the fluid allowed to pass through the flow gap 24 is smaller than the instantaneous flow rate of the fluid allowed to pass through the fluid channel 25.

[0030] Reference Figures 2 to 6 When the main shaft 22 is actuated along the first rotation direction, the damping diaphragm 23 rotates accordingly, thereby squeezing the fluid in the pressure chamber 21b. Since the one-way valve 26 remains closed, the fluid in the pressure chamber 21b can only flow to the pressure relief chamber 21c through the flow gap 24. Since the cross-sectional area of ​​the flow gap 24 is relatively small and the instantaneous flow rate is small, in the case of rapid squeezing impact, the damping diaphragm 23 withstands the rotational resistance along the second rotational direction applied by the fluid, that is, the resistance formed by the positive pressure difference between the pressure chamber 21b and the pressure relief chamber 21c on the damping diaphragm 23, which prevents the damping diaphragm 23 from rotating significantly. The damping effect is very obvious, and the rotation of the main shaft 22 along the first rotational direction is reasonably converted into the movement of the tensioning wheel 33 along the direction of loosening the chain, so as to prevent the damping diaphragm 23 from rotating significantly. Figure 2 As shown in the example, the tensioning wheel is rotated relative to the housing 21 in a first rotation direction to loosen the chain, so that the chain passes from the rear flywheel to the upper right of the guide wheel 32, and then passes from the lower left of the tensioning wheel 33 and extends to the right front flywheel, thereby effectively reducing the possibility of chain falling.

[0031] Reference Figures 2 to 6 When the main shaft 22 is actuated along the second rotation direction, the damping partition 23 rotates accordingly, thereby squeezing the fluid in the pressure relief chamber 21c. The valve core 261 opens the one-way valve 26 under the action of the positive pressure difference between the pressure relief chamber 21c and the pressure chamber 21b, and penetrates the fluid channel 25, so that the fluid in the pressure relief chamber 21c can easily flow to the pressure chamber 21b through the fluid channel 25, and the resistance is very small. The rotation of the main shaft 22 along the second rotation direction is reasonably converted into the movement of the tensioning wheel 33 in the direction of the tensioning chain, and the chain will not fall off.

[0032] It is understandable that when the fluid in the pressure relief chamber 21c is squeezed, a small portion of the fluid in the pressure relief chamber 21c can also flow to the pressure chamber 21b through the flow gap 24, but it is much smaller than the instantaneous flow rate of the fluid channel 25 and can therefore be ignored.

[0033] In addition, the hydraulic damper 20 will not affect the normal speed shifting operation of the rear derailleur. When the chain shifts from the small flywheel to the large flywheel, the tensioning wheel 33 rotates at a constant speed, and the speed is much lower than when encountering bumps, driving the main shaft 22 to rotate slowly along the first rotation direction. The fluid in the pressure chamber 21b is sufficient to flow to the pressure relief chamber 21c through the flow gap 24, and the resistance to the speed shifting operation is very small, which will not affect the normal speed shifting; when the chain shifts from the small flywheel to the large flywheel, it drives the main shaft 22 to rotate slowly along the second rotation direction, and the resistance to the speed shifting operation is even smaller, so the speed shifting can be easily achieved.

[0034] Reference Figure 6 The spring 262 extends in the horizontal direction, which is parallel to the water surface. direction That is to say, parallel to the flat ground, even if the bumps cause the valve core 261 to be overweight or weightless, the spring 262 will not deform abnormally in the horizontal direction, ensuring that the valve core 261 will not shift its position, preventing the chain from falling off due to the reverse opening of the one-way valve 26.

[0035] Since there is no need for strict sealing between the damping diaphragm 23 and the shell 21 , the requirements for the processing and assembly accuracy of the damping diaphragm 23 and the shell 21 are low.

[0036] In some embodiments, reference Figure 6 The one-way valve 26 also includes a valve port 263 constituting one section of the fluid channel 25. The valve port 263 gradually expands in the direction away from the pressure relief chamber 21c. The valve core 261 is spherical, and the valve port 263 is adapted to the shape of the valve core 261. Even if the bump causes the valve core 261 to be overweight or weightless, the valve core 261 can completely press against the valve port 263 under the horizontal elastic force of the spring 262; the valve core 261 moves away from the valve port 263 under the positive pressure difference between the pressure relief chamber 21c and the pressure chamber 21b, and the fluid passes through the valve port 263 and between the valve core 261 and the fluid channel 25, and finally enters the pressure chamber 21b.

[0037] Reference Figure 3 and Figure 5 In some embodiments, the shell 21 includes an end cover 211, a middle shell 212, a rotating side wall 213 and a partition plate 214. The main shaft 22 is rotatably connected to the middle shell 212. The rotating side wall 213 is arranged between the middle shell 212 and the end cover 211. The middle shell 212, the rotating side wall 213 and the end cover 211 are enclosed to form a closed inner cavity 21a. The rotating side wall 213 is extended toward the main shaft 22 and is provided with a partition plate 214. The partition plate 214 extends from the middle shell 212 to the end cover 211 and abuts against the damping partition 23 or the main shaft 22. The partition plate 214 and the damping partition 23 jointly divide the closed inner cavity 21a into a pressure chamber 21b and a pressure relief chamber 21c. Once the main shaft 22 rotates, the damping partition 23 will squeeze the pressure chamber 21b or the pressure relief chamber 21c.

[0038] Among them, the middle shell 212, the rotating side wall 213 and the partition plate 214 can be an integrally formed structure, the main shaft 22 and the middle shell 212 always maintain a sealed fit when they rotate relative to each other, and the end cover 211 is sealed with the end of the main shaft 22 and the end of the rotating side wall 213.

[0039] It is understandable that the partition plate 214 can directly abut against the outer peripheral surface of the main shaft 22. Figure 3 A sleeve portion 231 may also be provided on the damping baffle 23 , the sleeve portion 231 is fixedly sleeved on the main shaft 22 and wraps the main shaft 22 , and the partition plate 214 may abut against the outer wall of the sleeve portion 231 .

[0040] In some embodiments, reference Figure 3 and Figure 5 The flow gap 24 includes a first flow gap 241, which is formed between an end of the damping baffle 23 away from the main shaft 22 and the rotating side wall 213. When the main shaft 22 is actuated along the first rotation direction, the damping baffle 23 rotates accordingly, thereby squeezing the fluid in the pressure chamber 21b. The fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the first flow gap 241.

[0041] In order to further reduce the first flow gap 241 , the end of the damping baffle 23 away from the main shaft 22 may be configured as a curved surface structure.

[0042] In some embodiments, reference Figure 3The damping baffle 23 includes a sleeve portion 231 fixedly mounted on the main shaft 22 and a blade portion 232 extending radially from the sleeve portion 231 toward the rotating side wall 213. The flow gap 24 includes a second flow gap 242. The second flow gap 242 is formed between the outer wall of the sleeve portion 231 and the partition plate 214. When the main shaft 22 is actuated along the first rotation direction, the damping baffle 23 rotates accordingly, thereby squeezing the fluid in the pressure chamber 21b. The fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the second flow gap 242.

[0043] In some embodiments, reference Figure 5 The flow gap 24 includes a third flow gap 243, and the third flow gap 243 is formed between the damping baffle 23 and the end cover 211. When the main shaft 22 is actuated along the first rotation direction, the damping baffle 23 rotates accordingly, thereby squeezing the fluid in the pressure chamber 21b. The fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the third flow gap 243.

[0044] In some embodiments, reference Figure 3 and Figure 5 The flow gap 24 includes a fourth flow gap 244, and the fourth flow gap 244 is formed between the damping baffle 23 and the middle shell 212. When the main shaft 22 is actuated along the first rotation direction, the damping baffle 23 rotates accordingly, thereby squeezing the fluid in the pressure chamber 21b. The fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the fourth flow gap 244.

[0045] It can be understood that the flow gap 24 may include one or more of a first flow gap 241 , a second flow gap 242 , a third flow gap 243 , and a fourth flow gap 244 .

[0046] Reference Figure 6 In some embodiments, the fluid channel 25 is embedded in the middle shell 212, the head end of the fluid channel 25 is connected to the pressure relief chamber 21c through the channel inlet 251, and the tail end of the fluid channel 25 is connected to the pressure chamber 21b through the channel outlet 252. The fluid in the pressure relief chamber 21c can enter the fluid channel 25 through the channel inlet 251, then pass through the one-way valve 26, and finally enter the pressure chamber 21b through the channel outlet 252.

[0047] Among them, the rotation range of the damping baffle 23 does not cover the channel inlet 251 and the channel outlet 252, preventing the channel inlet 251 and the channel outlet 252 from being in the pressure chamber 21b or the pressure relief chamber 21c, thereby eliminating the situation where the connection function fails. Specifically, two stop positions can be set on the rotating side wall 213 or the partition plate 214 to limit the rotation range of the damping baffle 23.

[0048] In some embodiments, reference Figure 5A compensation chamber 28 is provided on the middle shell 212, and the compensation chamber 28 is configured to accommodate fluid. A through hole 281 is provided on the side of the compensation chamber 28 facing the pressure relief chamber 21c. The compensation chamber 28 is connected to the pressure relief chamber 21c through the through hole 281. The compensation chamber 28 and the pressure relief chamber 21c are always connected. The compensation chamber 28 is wholly or partially surrounded by a liquid sac membrane 282. The liquid sac membrane 282 is an elastic material and can be deformed. When the volume of the fluid in the closed inner cavity 21a changes due to temperature changes and other reasons in the pressure relief chamber 21c, the liquid sac membrane 282 is deformed appropriately, so that the compensation chamber 28 compensates the fluid to the pressure relief chamber 21c, or absorbs the fluid from the pressure relief chamber 21c, thereby ensuring the normal pressure in the pressure chamber 21b and the pressure relief chamber 21c and maintaining the damping stability.

[0049] Among them, refer to Figure 5 and Figure 6 The middle shell 212 can be composed of a middle shell base 2121 and a middle shell pressure cover 2122. A part of the compensation chamber 28 is surrounded by the liquid sac membrane 282, and the rest is surrounded by the middle shell base 2121. In addition to constituting a part of the liquid sac membrane 282, the liquid sac membrane 282 also extends between the middle shell base 2121 and the middle shell pressure cover 2122 and is in a sheet shape. The middle shell pressure cover 2122 locks the liquid sac membrane 282 on the middle shell base 2121 through fasteners, which facilitates the installation of the liquid sac membrane 282.

[0050] In addition, refer to Figure 6 The fluid channel 25 is embedded in the middle shell 212. The fluid channel 25 can be specifically enclosed by the middle shell base 2121, the liquid sac membrane 282 and the middle shell gland 2122 in sequence. Before the enclosure, the valve core 261 and the spring 262 are first assembled on the middle shell base 2121, and then the liquid sac membrane 282 is placed. Then, the middle shell gland 2122, the liquid sac membrane 282 and the middle shell base 2121 are locked by fasteners. The liquid sac membrane 282 can achieve a sealing effect between the middle shell gland 2122 and the middle shell base 2121, which is conducive to the installation of the one-way valve 26 and prevents the fluid channel 25 from leaking. The fluid channel 25 is arranged in the middle shell 212, which can effectively reduce the difficulty of assembly.

[0051] In some embodiments, reference Figure 5 and Figure 6 A tensioning elastic member 27 is provided between the housing 21 and the main shaft 22 , and the tensioning elastic member 27 is configured to apply a torque rotating along the second rotation direction to the main shaft 22 , that is, to indirectly apply a force to tension the chain to the tensioning wheel 33 .

[0052] Reference Figures 1 to 6 The present invention further discloses a rear derailleur, comprising a main body 10, a chain guide assembly 30 and the hydraulic damper 20 of the above embodiment.

[0053] Among them, refer to Figure 1The housing 21 is mounted on the main body 10, and the chain guide assembly 30 includes a guide plate 31 and a guide wheel 32 and a tension wheel 33 rotatably mounted on the guide plate 31. The guide plate 31 is fixedly connected to the other end of the main shaft 22. Figure 5 and Figure 6 The tensioning elastic member 27 is configured to apply a force to the tensioning wheel 33 to tension the chain.

[0054] Under normal conditions, the tensioning elastic member 27 is sufficient to meet the needs of the tensioning wheel 33 to tension the chain. When the bicycle is bumpy, if the tensioning wheel 33 is expected to move in the direction of loosening the chain, it is necessary to drive the guide plate 31 and the main shaft 22 to rotate in the first rotation direction, and the damping diaphragm 23 follows the rotation, thereby squeezing the fluid in the pressure chamber 21b. Since the one-way valve 26 remains in a closed state, the fluid in the pressure chamber 21b can only flow to the pressure relief chamber 21c through the flow gap 24. Since the cross-sectional area of ​​the flow gap 24 is relatively small and the instantaneous flow rate is small, in the case of rapid extrusion impact, the damping diaphragm 23 withstands the rotational resistance applied by the fluid in the second rotational direction, that is, the resistance formed by the positive pressure difference between the pressure chamber 21b and the pressure relief chamber 21c on the damping diaphragm 23, which prevents the damping diaphragm 23 and the guide plate 31 from rotating significantly. The damping effect is very obvious, which effectively reduces the occurrence of chain falling.

[0055] Since there is no need for strict sealing between the damping diaphragm 23 and the housing 21, the machining and assembly precision requirements for the damping diaphragm 23 and the housing 21 are low. Figure 6 The spring 262 of the one-way valve extends in the horizontal direction, parallel to the ground. Even if the bumps cause the valve core 261 to be overweight or weightless, the spring 262 will not deform abnormally in the horizontal direction, ensuring that the valve core 261 will not shift its position, preventing the chain from falling off due to the reverse opening of the one-way valve 26.

[0056] 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.

[0057] 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. Hydraulic damper, characterized in that: Having a horizontal direction and opposite first and second rotation directions, comprising: A housing having a sealed inner cavity therein, wherein the sealed inner cavity is configured to contain a fluid; A main shaft, which is rotatably connected to the shell around its own axis, and the main shaft can be actuated along a first rotation direction or a second rotation direction, one end of the main shaft extends into the closed inner cavity and is equipped with a damping baffle that can separate the closed inner cavity into a pressure-bearing chamber and a pressure-releasing chamber, and a flow gap is formed between the damping baffle and the shell for the fluid to flow; a fluid channel, which is arranged on the housing, wherein the head and tail ends of the fluid channel are connected to the pressure relief chamber and the pressure-bearing chamber respectively, and a one-way valve is arranged in the fluid channel, wherein the one-way valve comprises a valve core and a spring, wherein the spring extends in a horizontal direction and is arranged between the valve core and the housing, wherein the spring acts on the valve core and applies an elastic force to the valve core in a direction of blocking the fluid channel, and the valve core can penetrate the fluid channel under the action of a positive pressure difference between the pressure relief chamber and the pressure-bearing chamber; When the main shaft is actuated in a first rotation direction, the one-way valve remains closed, the fluid in the pressure-receiving chamber flows to the pressure-releasing chamber through the flow gap, and the damping diaphragm withstands the rotation resistance in a second rotation direction exerted by the fluid.

2. The hydraulic damper according to claim 1, characterized in that: The one-way valve also includes a valve port constituting a section of the fluid channel, the valve port gradually expands in a direction away from the pressure relief chamber, the valve core is spherical, and the valve core can be pressed against the valve port under the elastic force of the spring or move away from the valve port under the positive pressure difference between the pressure relief chamber and the pressure bearing chamber.

3. The hydraulic damper according to claim 1, characterized in that: The shell includes an end cover, a middle shell rotatably connected to the main shaft, and a rotating side wall arranged between the middle shell and the end cover. The middle shell, the rotating side wall and the end cover enclose the closed inner cavity. The rotating side wall is provided with a partition plate extending toward the main shaft. The partition plate extends from the middle shell to the end cover and abuts against the damping partition. The partition plate and the damping partition jointly separate the closed inner cavity into the pressure-bearing chamber and the pressure-relieving chamber.

4. The hydraulic damper according to claim 3, characterized in that: The flow gap includes a first flow gap formed between an end of the damping diaphragm away from the main shaft and the rotating side wall.

5. The hydraulic damper according to claim 3, characterized in that: The flow gap includes a second flow gap, the damping baffle includes a sleeve portion fixedly mounted on the main shaft and a blade portion radially extending from the sleeve portion toward the rotating side wall, and the second flow gap is formed between the outer side wall of the sleeve portion and the partition plate.

6. The hydraulic damper according to claim 3, characterized in that: The flow gap includes a third flow gap formed between the damping diaphragm and the end cover.

7. The hydraulic damper according to claim 3, characterized in that: The flow gap includes a fourth flow gap formed between the damping diaphragm and the middle shell.

8. The hydraulic damper according to claim 3, characterized in that: The fluid channel is embedded in the middle shell, the head end of the fluid channel is connected to the pressure relief chamber through the channel inlet, the tail end of the fluid channel is connected to the pressure chamber through the channel outlet, and the rotation range of the damping baffle does not cover the channel inlet and the channel outlet.

9. The hydraulic damper according to any one of claims 1 to 8, characterized in that: A tension elastic member is disposed between the housing and the main shaft, and the tension elastic member is configured to apply a torque to the main shaft to rotate along a second rotation direction.

10. A rear derailleur, characterized in that: include: main body; The hydraulic damper according to claim 9, wherein the housing is mounted on the body; The chain guide assembly comprises a guide plate and a guide wheel and a tension wheel rotatably mounted on the guide plate. The guide plate is fixedly connected to the other end of the main shaft, and the tensioning elastic member is configured to apply a force to tension the chain to the tensioning wheel.

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