Hydraulic damper and rear derailleur

Abstract

The application discloses a hydraulic damper and a rear derailleur with the same, which comprises a shell with a closed inner cavity inside; a main shaft with one end extending into the closed inner cavity and being provided with a damping partition plate capable of separating the closed inner cavity into a pressure bearing chamber and a pressure relief chamber, a flow gap being formed between the damping partition plate and the shell for fluid circulation; a fluid channel with two ends respectively communicating with the pressure relief chamber and the pressure bearing chamber, the fluid channel being provided with a one-way valve, the one-way valve comprising a valve core and a spring, the spring extending along a horizontal direction and being arranged between the valve core and the shell; when the main shaft is actuated along a first rotating direction, the fluid in the pressure bearing chamber flows to the pressure relief chamber through the flow gap, and the damping partition plate bears the rotating resistance in a second rotating direction exerted by the fluid. The hydraulic damper has very obvious damping effect, effectively reduces the chain dropping situation, has low machining and assembling precision requirements for the damping partition plate and the shell, and prevents the chain dropping situation caused by the reverse opening of the one-way valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bicycles, in particular to a damper and a rear derailleur. BACKGROUND

[0002] When a bicycle is subjected to severe jolts, the tension wheel has a tendency to move instantaneously and rapidly towards the direction of the slack chain due to the upward and downward inertia, and the chain is prone to fall off, which is particularly obvious on a mountain bike. To deal with this situation, a damper is developed, which can prevent the tension wheel from abnormal jumping.

[0003] At present, the damper is mostly in the form of spring damping. When dealing with rapid and severe jolts, the damping spring needs to be subjected to a certain degree of impact before it can react and implement reverse damping. The effect of reverse damping is often proportional to the stroke of the damping spring, which causes a delay in reaction and makes the effect of preventing the chain from falling off not obvious. Some dampers are in the form of hydraulic damping. Some hydraulic dampers have a relatively complex structure, high requirements for the sealing performance of the parts of the damper, and high requirements for the machining and assembly precision. Moreover, the parts of the damper are prone to abnormal failure in the state of superweight or weightlessness caused by severe jolts, and the chain is also prone to fall off. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a damper, which has obvious damping effect and low requirements for sealing performance.

[0005] The present application also provides a rear derailleur with the damper.

[0006] The hydraulic damper according to the first aspect of the present application has a horizontal direction and opposite first and second rotating directions, and comprises: a housing having a closed inner cavity inside, the closed inner cavity being configured to contain fluid; a main shaft rotatably connected to the housing about an axis thereof, the main shaft being capable of being actuated in the first or second rotating direction, one end of the main shaft extending into the closed inner cavity and being provided with a damping partition plate capable of separating the closed inner cavity into a pressure-bearing chamber and a pressure-relief chamber, a flow gap for the fluid to flow through being formed between the damping partition plate and the housing; and a fluid passage provided on the housing, the fluid passage having two ends respectively communicating with the pressure-relief chamber and the pressure-bearing chamber, the fluid passage being provided with a one-way valve, the one-way valve comprising a valve core and a spring, the spring extending in the horizontal direction and being arranged between the valve core and the housing, the spring acting on the valve core and applying an elastic force to the valve core in a direction of blocking the fluid passage, the valve core being capable of penetrating through the fluid passage 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 the first rotating direction, the one-way valve remains in a closed state, the fluid in the pressure-bearing chamber flows to the pressure-relief chamber through the flow gap, and the damping partition plate bears a rotating resistance in the second rotating direction exerted by the fluid.

[0007] The hydraulic damper has at least the following beneficial effects: when the main shaft is actuated in the second rotating direction, the damping partition plate rotates and presses the fluid in the pressure-relief chamber, the valve core opens the one-way valve under the action of a positive pressure difference between the pressure-relief chamber and the pressure-bearing chamber, penetrates through the fluid passage, and makes the fluid in the pressure-relief chamber flow to the pressure-bearing chamber through the fluid passage with very small resistance, thereby reasonably converting the rotation of the main shaft in the second rotating direction into the movement of the tensioning wheel in the direction of the tensioning chain and preventing chain dropping; when the main shaft is actuated in the first rotating direction, the damping partition plate rotates and presses the fluid in the pressure-bearing chamber, the fluid in the pressure-bearing chamber can only flow to the pressure-relief chamber through the flow gap due to the closed state of the one-way valve, the instantaneous flow is small due to the relatively small cross-sectional area of the flow gap, and the damping partition plate bears a rotating resistance in the second rotating direction exerted by the fluid in the case of rapid extrusion impact, that is, the damping partition plate bears a resistance formed by a positive pressure difference between the pressure-bearing chamber and the pressure-relief chamber, thereby preventing the damping partition plate from rotating greatly and making the damping effect very obvious, reasonably converting the rotation of the main shaft in the first rotating direction into the movement of the tensioning wheel in the direction of the relaxation chain and effectively reducing the occurrence of chain dropping; the spring of the one-way valve extends in the horizontal direction and is parallel to the ground, so that the spring will not abnormally deform in the horizontal direction even in the case of overloading or weightlessness of the valve core caused by bumps, the position of the valve core is ensured not to deviate, and the occurrence of chain dropping caused by reverse opening of the one-way valve is prevented.

[0008] According to some embodiments of the present application, the one-way valve further comprises a valve port constituting one section of the fluid passage, the valve port is gradually flared in a direction away from the pressure relief chamber, the valve core is spherical, and the valve core is capable of abutting against the valve port under the elastic force of the spring or moving away from the valve port under the positive pressure difference between the pressure relief chamber and the pressure bearing chamber.

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

[0010] According to some embodiments of the present application, the flow gap comprises a first flow gap formed between one end of the damping partition plate away from the main shaft and the rotary side wall.

[0011] According to some embodiments of the present application, the flow gap comprises a second flow gap, the damping partition plate comprises a sleeve portion fixedly sleeved on the main shaft and a blade portion extending radially from the sleeve portion towards the rotary 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 application, the flow gap comprises a third flow gap formed between the damping partition plate and the end cover.

[0013] According to some embodiments of the present application, the flow gap comprises a fourth flow gap formed between the damping partition plate and the middle shell.

[0014] According to some embodiments of the present application, the fluid passage is embedded in the middle shell, a leading end of the fluid passage is communicated with the pressure relief chamber through a passage inlet, a trailing end of the fluid passage is communicated with the pressure bearing chamber through a passage outlet, and a rotation range of the damping partition plate does not cover the passage inlet and the passage outlet.

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

[0016] According to a second aspect of the present invention, a rear derailleur includes: a main body; a hydraulic damper according to the first aspect of the present invention, wherein the housing is mounted on the main body; and a chain guide assembly including 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 element is configured to apply a tensioning force to the tension wheel.

[0017] At least the following beneficial effects are achieved: Under normal conditions, the tensioning elastic element is sufficient to meet the needs of the tensioning wheel for tensioning the chain. When the bicycle experiences bumps, if the tensioning wheel is expected to move in the direction of slack chain, it needs to drive the guide plate and main shaft to rotate in the first rotation direction. The damping baffle rotates accordingly, thereby compressing the fluid in the pressure chamber. Since the one-way valve remains closed, the fluid in the pressure chamber can only flow to the pressure relief chamber through the flow gap. Because the cross-sectional area of ​​the flow gap is relatively small and the instantaneous flow rate is small, under rapid compression and impact, the damping baffle withstands the force applied by the fluid along the second rotation direction. The rotational resistance refers to the resistance formed by the positive pressure difference between the pressure chamber and the pressure relief chamber on the damping diaphragm. This prevents the damping diaphragm and guide plate from rotating significantly, and the damping effect is very obvious, effectively reducing the occurrence of chain drop. Since there is no need for a strict seal between the damping diaphragm and the shell, the requirements for the processing and assembly precision of the damping diaphragm and the shell are low. Moreover, the spring of the one-way valve extends horizontally and is parallel to the ground. Even if the valve core is overweight or weightless due to bumps, the spring will not deform abnormally in the horizontal direction, ensuring that the valve core will not shift its position and preventing the chain drop caused by the one-way valve opening in the opposite direction.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 This is a schematic diagram of the rear derailleur in an embodiment of the present invention;

[0021] Figure 2 for Figure 1 A schematic diagram of the structure after the hidden end cap is installed;

[0022] Figure 3 for Figure 2 A schematic diagram of a partial structure;

[0023] Figure 4 This is a schematic diagram of the hydraulic damper in an embodiment of the present invention;

[0024] Figure 5 for Figure 4A-A rotational section view of FIG. 1;

[0025] Figure 6 A-A rotational section view of FIG. 1; Figure 4 B-B section view of FIG. 1.

[0026] Reference signs: 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 gland 2122, rotary side wall 213, partition plate 214, main shaft 22, damping partition plate 23, sleeve part 231, vane part 232, flow gap 24, first flow gap 241, second flow gap 242, third flow gap 243, fourth flow gap 244, fluid passage 25, passage inlet 251, passage 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 bag film 282, chain guide assembly 30, guide plate 31, guide wheel 32, tensioning wheel 33. DETAILED DESCRIPTION

[0027] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application.

[0028] In the description of the present application, it is understood that the orientation description, such as horizontal, inner, outer, upper, lower, left and right, and the like, is based on the orientation or position relationship shown in the drawings, only for the purpose of facilitating the description of the present application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0029] In the description of the present application, if the first, second, third and fourth are described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the sequence of technical features indicated.

[0030] In the description of the present application, unless otherwise explicitly limited, the words such as arrangement, installation, connection, rotation, rotation, communication, penetration, plugging and the like should be interpreted in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0031] Referring to Figures 1 to 6The application discloses a hydraulic damper, which has a horizontal direction and opposite first and second rotating directions, and comprises a shell 21, a main shaft 22, a damping partition plate 23, a flow gap 24, a fluid channel 25 and a one-way valve 26.

[0032] Wherein, referring to Figure 3 and Figure 5 , the shell 21 has a sealed inner cavity 21a inside, the sealed inner cavity 21a is configured to contain fluid, the main shaft 22 is rotationally connected to the shell 21 around its own axis, the main shaft 22 can be actuated in the first or second rotating direction, one end of the main shaft 22 extends into the sealed inner cavity 21a and is provided with the damping partition plate 23, the damping partition plate 23 can divide the sealed inner cavity 21a into a pressure-bearing chamber 21b and a pressure-relief chamber 21c, and the flow gap 24 for fluid communication is formed between the damping partition plate 23 and the shell 21.

[0033] Referring to Figure 6 , the fluid channel 25 is arranged on the shell 21, the fluid channel 25 has two ends respectively communicating with the pressure-relief chamber 21c and the pressure-bearing chamber 21b, and the one-way valve 26 is arranged in the fluid channel 25.

[0034] The one-way valve 26 specifically comprises a valve core 261 and a spring 262, the spring 262 extends along the horizontal direction and is arranged between the valve core 261 and the shell 21, the spring 262 acts on the valve core 261 and exerts a spring force on the valve core 261 in the direction of plugging the fluid channel 25, so that the one-way valve 26 can be kept in a normally closed state; the valve core 261 can penetrate through the fluid channel 25 under the action of the positive pressure difference between the pressure-relief chamber 21c and the pressure-bearing chamber 21b, so as to open the one-way valve 26.

[0035] It should be noted that the cross-sectional area of the flow gap 24 is smaller than that of the fluid channel 25, or even much smaller than that of the fluid channel 25, so that the instantaneous flow rate allowed by the flow gap 24 to pass through fluid is smaller than that allowed by the fluid channel 25 to pass through fluid.

[0036] Referring to Figures 2 to 6 , when the main shaft 22 is actuated in the first rotating direction, the damping partition plate 23 rotates and presses the fluid in the pressure-bearing chamber 21b, the fluid in the pressure-bearing chamber 21b can only flow to the pressure-relief chamber 21c through the flow gap 24 due to the closed state of the one-way valve 26, the cross-sectional area of the flow gap 24 is relatively small, so the instantaneous flow rate is small, in the case of rapid extrusion impact, the damping partition plate 23 bears the rotating resistance of the fluid in the second rotating direction, that is, the damping partition plate 23 bears the resistance formed by the positive pressure difference between the pressure-bearing chamber 21b and the pressure-relief chamber 21c, so as to prevent the damping partition plate 23 from rotating greatly, and the damping effect is very obvious, the rotation of the main shaft 22 in the first rotating direction is reasonably converted into the movement of the tensioning wheel 33 in the direction of relaxing the chain, so thatFigure 2 As shown in the example, the design of rotating the tensioning wheel relative to the housing 21 in the first rotation direction to slacken the chain, so that the chain is routed from the rear sprocket to the right upper side of the guide wheel 32, and then from the left lower side of the tensioning wheel 33 to the right front sprocket, thereby effectively reducing the occurrence of chain drop.

[0037] Referring to Figures 2 to 6 When the main shaft 22 is actuated in the second rotation direction, the damping baffle 23 rotates to press the fluid in the pressure relief chamber 21c, and 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 bearing chamber 21b, and the fluid in the pressure relief chamber 21c flows through the fluid passage 25 to the pressure bearing chamber 21b with very small resistance, so that the rotation of the main shaft 22 in 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 drop does not occur.

[0038] It can be understood that when the fluid in the pressure relief chamber 21c is pressed, a small part of the fluid in the pressure relief chamber 21c can also flow to the pressure bearing chamber 21b through the flow gap 24, but the instantaneous flow is much smaller than that of the fluid passage 25, so it can be ignored.

[0039] In addition, the hydraulic damper 20 does not affect the normal gear shifting operation of the rear derailleur. When the chain is shifted from the small sprocket to the large sprocket, the tensioning wheel 33 rotates at a uniform speed, and the speed is much smaller than that when it encounters bumps. The main shaft 22 is driven to rotate slowly in the first rotation direction, and the fluid in the pressure bearing chamber 21b is sufficient to flow to the pressure relief chamber 21c through the flow gap 24, and the resistance to the gear shifting operation is very small, which does not affect the normal gear shifting; when the chain is shifted from the small sprocket to the large sprocket, the main shaft 22 is driven to rotate slowly in the second rotation direction, and the resistance to the gear shifting operation is smaller, so that the gear shifting can be easily realized.

[0040] Referring to Figure 6 The spring 262 extends in the horizontal direction, that is, parallel to the water surface Direction That is, parallel to the flat ground. Even if the bumps cause the valve core 261 to be overweight or weightless, the spring 262 will not abnormally deform in the horizontal direction, which ensures that the valve core 261 will not deviate from its position and prevents the chain from dropping due to the reverse opening of the one-way valve 26.

[0041] Since there is no need for strict sealing between the damping baffle 23 and the housing 21, the machining and assembly precision requirements of the damping baffle 23 and the housing 21 are low.

[0042] In some embodiments, referring to Figure 6The one-way valve 26 further comprises a valve port 263 constituting one section of the fluid passage 25, the valve port 263 is gradually flared in a direction away from the pressure relief chamber 21c, the valve core 261 is spherical, the shape of the valve port 263 is matched with the valve core 261, that is, even if the valve core 261 is in an over-weight or weightless state caused by jolting, the valve core 261 can be tightly abutted against the valve port 263 under the horizontal elastic force of the spring 262; the valve core 261 is away from the valve port 263 under the action of the positive pressure difference between the pressure relief chamber 21c and the pressure bearing chamber 21b, the fluid passes through the valve port 263 and passes between the valve core 261 and the fluid passage 25, and finally enters the pressure bearing chamber 21b.

[0043] With reference to Figure 3 and Figure 5 In some embodiments, the shell 21 comprises an end cover 211, a middle shell 212, a rotary side wall 213 and a partition plate 214, the main shaft 22 is rotationally connected to the middle shell 212, the rotary side wall 213 is arranged between the middle shell 212 and the end cover 211, the middle shell 212, the rotary side wall 213 and the end cover 211 enclose to form a closed inner cavity 21a, the rotary side wall 213 is provided with the partition plate 214 extending towards the main shaft 22, the partition plate 214 extends from the middle shell 212 to the end cover 211 and abuts against the damping partition plate 23 or the main shaft 22, the partition plate 214 and the damping partition plate 23 jointly divide the closed inner cavity 21a into the pressure bearing chamber 21b and the pressure relief chamber 21c, once the main shaft 22 rotates, the damping partition plate 23 will press the pressure bearing chamber 21b or the pressure relief chamber 21c.

[0044] The middle shell 212, the rotary 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 sealed cooperation when relatively rotating, and the end cover 211 is in sealed cooperation with the end of the main shaft 22 and the end of the rotary side wall 213.

[0045] It can be understood that the partition plate 214 can directly abut against the outer circumferential surface of the main shaft 22, with reference to Figure 3 The sleeve portion 231 is fixedly sleeved on the main shaft 22 and wraps the main shaft 22, and the partition plate 214 can abut against the outer side wall of the sleeve portion 231.

[0046] In some embodiments, with reference to Figure 3 and Figure 5 The flow gap 24 comprises a first flow gap 241 formed between one end of the damping partition plate 23 away from the main shaft 22 and the rotary side wall 213, when the main shaft 22 is actuated in the first rotation direction, the damping partition plate 23 rotates and presses the fluid in the pressure bearing chamber 21b, and the fluid in the pressure bearing chamber 21b can flow to the pressure relief chamber 21c through the first flow gap 241.

[0047] To further reduce the first flow gap 241, the damping baffle 23 can be further provided with a curved structure away from the end of the main shaft 22.

[0048] In some embodiments, referring to Figure 3 , the damping baffle 23 includes a sleeve portion 231 fixedly sleeved on the main shaft 22 and a blade portion 232 extended from the sleeve portion 231 to the rotary side wall 213 in the radial direction, the flow gap 24 includes a second flow gap 242 formed between the outer side wall of the sleeve portion 231 and the partition plate 214, when the main shaft 22 is actuated in the first rotation direction, the damping baffle 23 rotates and presses the fluid in the pressure chamber 21b, and the fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the second flow gap 242.

[0049] In some embodiments, referring to Figure 5 , the flow gap 24 includes a third flow gap 243 formed between the damping baffle 23 and the end cover 211, when the main shaft 22 is actuated in the first rotation direction, the damping baffle 23 rotates and presses the fluid in the pressure chamber 21b, and the fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the third flow gap 243.

[0050] In some embodiments, referring to Figure 3 and Figure 5 , the flow gap 24 includes a fourth flow gap 244 formed between the damping baffle 23 and the middle shell 212, when the main shaft 22 is actuated in the first rotation direction, the damping baffle 23 rotates and presses the fluid in the pressure chamber 21b, and the fluid in the pressure chamber 21b can flow to the pressure relief chamber 21c through the fourth flow gap 244.

[0051] It can be understood that the flow gap 24 can include one or more of the first flow gap 241, the second flow gap 242, the third flow gap 243 and the fourth flow gap 244.

[0052] Referring to Figure 6 , in some embodiments, the fluid channel 25 is embedded in the middle shell 212, the leading end of the fluid channel 25 is connected to the pressure relief chamber 21c through the channel inlet 251, the trailing 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, pass through the one-way valve 26, and finally enter the pressure chamber 21b through the channel outlet 252.

[0053] The rotation range of the damping partition plate 23 does not cover the channel entrance 251 and the channel exit 252, preventing the channel entrance 251 and the channel exit 252 from being in the pressure-bearing chamber 21b or the pressure relief chamber 21c, and eliminating the situation that the communication function fails. Specifically, two stop positions can be arranged on the rotary side wall 213 or the partition plate 214 to limit the rotation range of the damping partition plate 23.

[0054] In some embodiments, referring to Figure 5 , the middle shell 212 is provided with a compensation chamber 28 configured to accommodate fluid. The compensation chamber 28 is provided with a through hole 281 on the side facing the pressure relief chamber 21c, and the compensation chamber 28 communicates with the pressure relief chamber 21c through the through hole 281. The compensation chamber 28 and the pressure relief chamber 21c always communicate with each other. The compensation chamber 28 is wholly or partially surrounded by a liquid bag film 282. The liquid bag film 282 is made of elastic material and can deform. When the volume of the fluid in the sealed inner cavity 21a changes due to temperature change or other reasons, the liquid bag film 282 deforms moderately to compensate the fluid in the compensation chamber 28 or absorb the fluid from the pressure relief chamber 21c, so as to maintain the normal pressure in the pressure-bearing chamber 21b and the pressure relief chamber 21c and maintain the damping stability.

[0055] In some embodiments, referring to Figure 5 and Figure 6 , the middle shell 212 can be combined by a middle shell base 2121 and a middle shell gland 2122. The compensation chamber 28 is partially surrounded by the liquid bag film 282 and partially surrounded by the middle shell base 2121. The liquid bag film 282 extends between the middle shell base 2121 and the middle shell gland 2122 in a sheet shape. The middle shell gland 2122 locks the liquid bag film 282 on the middle shell base 2121 by fasteners, facilitating the installation of the liquid bag film 282.

[0056] In addition, referring to Figure 6 , the fluid channel 25 is embedded in the middle shell 212. Specifically, the fluid channel 25 can be enclosed by the middle shell base 2121, the liquid bag film 282, and the middle shell gland 2122 in sequence. Before being enclosed, the valve core 261 and the spring 262 are assembled on the middle shell base 2121, and then the liquid bag film 282 is placed. The middle shell gland 2122, the liquid bag film 282, and the middle shell base 2121 are locked by fasteners. The liquid bag film 282 can realize 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. Embedding the fluid channel 25 in the middle shell 212 can effectively reduce the assembly difficulty.

[0057] In some embodiments, referring to Figure 5 and Figure 6The tensioning elastic member 27 is configured to apply a torque along the second rotation direction to the main shaft 22, that is, indirectly to the tensioning wheel 33 to apply a force to the tensioning chain.

[0058] With reference to Figures 1 to 6 The application also discloses a rear derailleur, which comprises a main body 10, a chain guide assembly 30 and the hydraulic damper 20 of the above embodiment.

[0059] With reference to Figure 1 The housing 21 is mounted on the main body 10, and the chain guide assembly 30 comprises a guide plate 31, a guide wheel 32 and a tensioning 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, with reference to Figure 5 and Figure 6 The tensioning elastic member 27 is configured to apply a force to the tensioning chain to the tensioning wheel 33.

[0060] In a normal state, the tensioning elastic member 27 is sufficient to meet the needs of the tensioning wheel 33 to tension the chain, when the bicycle is in a bumpy situation, if the tensioning wheel 33 is expected to move in the direction of the relaxed chain, the guide plate 31 and the main shaft 22 need to be driven to rotate along the first rotation direction, the damping partition plate 23 rotates, and then the fluid in the pressure chamber 21b is extruded, 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, the instantaneous flow is small, in the case of rapid extrusion impact, the damping partition plate 23 bears the rotational resistance of the fluid along the second rotation direction, that is, the damping partition plate 23 is subjected to the resistance formed by the positive pressure difference between the pressure chamber 21b and the pressure relief chamber 21c, preventing the damping partition plate 23 and the guide plate 31 from rotating greatly, the damping effect is very obvious, effectively reducing the situation of chain falling.

[0061] Since there is no strict sealing between the damping partition plate 23 and the housing 21, the machining and assembly precision of the damping partition plate 23 and the housing 21 is low. Figure 6 The spring 262 of the one-way valve extends in the horizontal direction, parallel to the ground, even if the valve core 261 is in an overweight or weightless state caused by bumping, the spring 262 will not abnormally deform in the horizontal direction, ensuring that the valve core 261 will not deviate from its position, preventing the situation of chain falling caused by the reverse opening of the one-way valve 26.

[0062] The technical features of the above embodiments can be combined arbitrarily, in order to make the description simple, not all possible combinations of the technical features in the above embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0063] Of course, the present application is not limited to the above-described embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present application, and these equivalent modifications or substitutions are included in the scope defined by the claims of the present application.

Claims

1. A hydraulic damper, characterized in that, Having a horizontal direction and opposite first and second rotational directions, including: The housing has a sealed inner cavity configured to contain fluid. A main shaft is 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. One end of the main shaft extends into the sealed inner cavity and is equipped with a damping baffle that can divide the sealed inner cavity into a pressure chamber and a pressure relief chamber. A flow gap is formed between the damping baffle and the housing to allow the fluid to flow. The housing includes an end cap, a middle shell rotatably connected to the main shaft, and a rotating sidewall disposed between the middle shell and the end cap. A fluid channel is embedded in the middle shell. The first end of the fluid channel is connected to the pressure relief chamber through the channel inlet, and the last end of the fluid channel is connected to the pressure bearing chamber through the channel outlet. The rotation range of the damping baffle does not cover the channel inlet and the channel outlet. A one-way valve is provided in the fluid channel. The one-way valve includes a valve core and a spring. The spring extends horizontally and is disposed between the valve core and the shell. The spring acts on the valve core and applies a spring force to the valve core in the direction of blocking the fluid channel. The valve core can penetrate the fluid channel under the positive pressure difference between the pressure relief chamber and the pressure bearing chamber. When the main shaft is actuated in the first rotation direction, the one-way valve remains closed, the fluid in the pressure chamber flows through the flow gap to the pressure relief chamber, and the damping baffle bears the rotational resistance applied by the fluid in the second rotation direction.

2. The hydraulic damper according to claim 1, characterized in that, The one-way valve also includes a valve port that forms a section of the fluid passage. The valve port gradually widens in the direction away from the pressure relief chamber. The valve core is spherical. The valve core can press 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 middle shell, the rotating sidewall, and the end cap enclose the sealed inner cavity. The rotating sidewall extends toward the main shaft and is provided with a partition plate. The partition plate extends from the middle shell to the end cap and abuts against the damping partition plate. The partition plate and the damping partition plate together divide the sealed inner cavity into the pressure chamber and the pressure relief chamber.

4. The hydraulic damper according to claim 3, characterized in that, The flow gap includes a first flow gap, which is formed between the end of the damping plate away from the main shaft and the rotating sidewall.

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

6. The hydraulic damper according to claim 3, characterized in that, The flow gap includes a third flow gap, which is formed between the damping septum and the end cap.

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

8. The hydraulic damper according to any one of claims 1 to 7, characterized in that, A tensioning elastic element is provided between the housing and the main shaft, and the tensioning elastic element is configured to apply a torque to the main shaft in a second rotational direction.

9. A rear derailleur, characterized in that, include: main body; The hydraulic damper as described in claim 8, wherein the housing is mounted on the main body; A chain guide assembly includes 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 element is configured to apply a tensioning force to the tension wheel.

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