Magnetorheological damper using permanent magnetic sealing ring

Abstract

A kind of magnetorheological damper using permanent magnetic seal ring, including cylinder assembly, piston assembly;Cylinder assembly includes working cylinder, working cylinder one end is sealed through sealing guide mechanism and is sealed with piston rod;Working cylinder other end is provided with gas compensation assembly;Piston assembly includes piston rod, and piston rod is connected with piston head assembly;Piston head assembly includes piston sleeve, and iron core is arranged in piston sleeve, and the left and right ends of iron core are correspondingly clamped with upper end cover and lower end cover and are combined into an integral whole with piston sleeve;Excitation coil is provided in piston sleeve and located outside iron core, and excitation coil controls the damping performance of magnetorheological fluid.The magnetorheological damper using permanent magnetic seal ring provided by the application can effectively reduce the leakage of magnetorheological fluid.

Description

Technical Field

[0001] This invention relates to the field of magnetorheological vibration dampers, and in particular to a magnetorheological vibration damper using a permanent magnetic sealing ring. Background Technology

[0002] Magnetorheological dampers (MRDs) are intelligent dampers that utilize the magnetorheological effect to adjust damping force. They have wide applications in mechanical vibration control, automotive suspension systems, and seismic resistance of building structures. Sealing is a key limiting factor for the commercial application of MRDs, as it not only affects the damper's ability to prevent magnetorheological fluid leakage but also determines its durability and maintenance costs in complex environments, thus impacting market acceptance and trust in this high-tech product.

[0003] Currently, most magnetorheological vibration dampers utilize the elastic deformation of O-rings to achieve sealing. However, ferromagnetic particles between the O-ring and the sealing surface accelerate O-ring wear, and the frictional heat generated by the relative movement between the O-ring and the sealing surface also accelerates O-ring aging. Existing commercial magnetorheological vibration dampers, due to their assembly methods such as edge-rolling and welding, are not disassembled, meaning that the durability of the sealing components cannot be enhanced through regular maintenance. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a single-cylinder inflatable magnetorheological fluid vibration damper. Based on the traditional piston, the permanent magnetic O-ring seal can adsorb ferromagnetic particles in the magnetorheological fluid, filling the gap between the piston rod and the sealing guide mechanism, thereby effectively reducing the risk of magnetorheological fluid leakage. Simultaneously, through reasonable calculation, the magnetism of the permanent magnetic O-ring seal is just enough to adsorb a sufficient amount of ferromagnetic particles without significantly reducing the mass fraction of ferromagnetic particles in the magnetorheological fluid or causing sedimentation.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A magnetorheological vibration damper using a permanent magnetic sealing ring includes a cylinder assembly, a piston assembly, and a gas compensation assembly; The cylinder assembly includes a working cylinder, one end of which is sealed by a sealing guide mechanism and sealed with the piston rod; the other end of the working cylinder is provided with a gas compensation assembly. The piston assembly includes a piston rod, which is connected to a piston head assembly. The piston head assembly includes a piston sleeve, in which an iron core is arranged. The left and right ends of the iron core are correspondingly engaged with the upper and lower end caps and are combined with the piston sleeve as a whole. An excitation coil is provided inside the piston sleeve and outside the iron core. The excitation coil controls the damping performance of the magnetorheological fluid. The gas compensation assembly includes a gas storage cylinder, one side of which is connected to the working cylinder and the other side is equipped with a gas filling valve. The gas storage cylinder is filled with inert gas. A floating piston is arranged in the working cylinder near the gas storage cylinder. The floating piston performs reciprocating linear motion under the action of the gas.

[0007] The piston rod has an axially penetrating wire hole at its center, and the wire is arranged in the wire hole and sealed with epoxy resin.

[0008] The sealing and guiding mechanism includes a guide body, the outer side of which is sealed to the working cylinder by an O-ring; the inner side of the guide body is sealed to the piston rod by a permanent magnetic O-ring.

[0009] The inner wall of the sealing guide mechanism is provided with multiple sets of annular grooves, and a permanent magnetic O-ring is installed in each annular groove. The number of permanent magnetic O-rings is matched with the working environment of the magnetorheological vibration damper.

[0010] A first piston ring is installed on the inner side of the guide body, and a first sealing ring and a second sealing ring are installed on the front and rear sides of the guide body, respectively.

[0011] The connection between the working cylinder and the gas storage cylinder is sealed by a third sealing ring.

[0012] The portion of the gas storage cylinder located inside the working cylinder forms a boss with the side wall of the working cylinder, and the boss limits the position of the floating piston away from the piston head assembly.

[0013] The middle section of the outer wall of the piston sleeve protrudes outward, and the middle section of the outer wall of the piston sleeve is in contact with the working cylinder and guides the left and right movement of the piston head assembly.

[0014] The excitation coil is sealed by an epoxy resin sealing ring.

[0015] A method for sealing using a permanent magnetic sealing ring and a magnetorheological vibration damper includes the following steps: Step 1: First, a set of permanent magnetic O-rings closest to the magnetorheological fluid attracts ferromagnetic particles in the magnetorheological fluid to deposit at the installation position of the permanent magnetic O-rings, thereby blocking the passage of other unattracted ferromagnetic particles to achieve the sealing purpose. Step 2: Then, the first piston ring cleans up any small amount of ferromagnetic particles leaking from the mounting position of the permanent magnet O-ring; at the same time, the first piston ring 7 prevents leakage of the magnetorheological fluid; Step 3: Finally, the other permanent magnetic O-rings on the side away from the magnetorheological fluid can attract a very small number of ferromagnetic particles passing through the first piston ring to achieve the purpose of sealing.

[0016] This invention provides a single-cylinder air-filled magnetorheological fluid vibration damper, which has the following technical advantages: 1) Compared to traditional magnetorheological dampers, this device operates with the piston rod reciprocating linearly along the working cylinder, and the piston rod moving relative to the sealing guide mechanism, while other component connections remain relatively stationary. Therefore, the risk of leakage is highest at the seal between the piston rod and the sealing guide mechanism. To address this issue, this invention features a permanent magnetic O-ring seal that adsorbs ferromagnetic particles from the magnetorheological fluid, filling the gap between the piston rod and the sealing guide mechanism, thus effectively reducing the risk of magnetorheological fluid leakage. Furthermore, through careful calculation, the magnetism of the permanent magnetic O-ring seal is precisely sufficient to adsorb a sufficient amount of ferromagnetic particles without significantly reducing the mass fraction of ferromagnetic particles in the magnetorheological fluid or causing sedimentation. Additionally, different sealing components are provided at other connections to ensure that the magnetorheological fluid does not leak. The floating piston in the gas compensation assembly provides gas compensation for the single-rod, single-cylinder damper.

[0017] 2) By simulating the magnetic circuit and particle dynamics, the magnetic flux density of the permanent magnetic O-ring is determined, and the position and size of the permanent magnetic O-ring are adjusted so that it only adsorbs a sufficient amount of particles to form a dense deposition layer, thereby achieving a sealing effect. After this layer is formed, other magnetorheological fluids will no longer be attracted by the permanent magnetic O-ring, so as not to significantly reduce the mass fraction of ferromagnetic particles in the magnetorheological fluid.

[0018] 3) Permanent magnetic O-rings ensure wear resistance and overcome frictional heat: The inner layer of the permanent magnetic O-ring uses high-hardness rare-earth permanent magnet materials, such as samarium-cobalt alloy, which can withstand temperatures above 350℃. The surface can be plated with chromium or tungsten carbide coatings to improve wear resistance and reduce frictional heat generation. The outer rubber layer uses fluororubber or silicone rubber, with a temperature resistance range of 200~250℃ and excellent resistance to thermal oxidation.

[0019] The sealing guide mechanism 2 is made of aluminum alloy, which has high thermal conductivity and can dissipate frictional heat in a timely manner. Furthermore, it employs two sets of permanent magnetic O-rings arranged in layers to distribute the frictional load at single points and prevent localized overheating.

[0020] 4) This device enables effective disassembly: The sealing guide mechanism 2 is threaded to the end of the working cylinder 8, and can be separated by rotating it. The piston rod 1 is threaded to the piston head assembly, and can be separated by rotating it counterclockwise. The charging valve 23 in the gas compensation assembly is removable, facilitating the maintenance of the inert gas in the gas storage cylinder 21. All of these features are designed for effective disassembly of this device. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the structure of the present invention cut along the axial direction.

[0022] Figure 2 This is an exploded view of the present invention.

[0023] Figure 3 This is a front sectional view of the present invention.

[0024] Figure 4 This is a cross-sectional schematic diagram of the sealing guide mechanism in this invention.

[0025] Figure 5 This is a schematic diagram of the sealing principle at the sealing guide mechanism in this invention.

[0026] In the diagram: Piston rod 1, sealing guide mechanism 2, first sealing ring 3, first O-ring 4a, second O-ring 4b, second sealing ring 5, first permanent magnetic O-ring 6a, second permanent magnetic O-ring 6b, first piston ring 7, working cylinder 8, upper end cover 9, piston sleeve 10, iron core 11, lower end cover 12, first epoxy resin sealing ring 13a, second epoxy resin sealing ring 13b, first excitation coil 14a, second excitation coil 14b, wire retaining steel ring 15, first O-ring 16, second piston ring 17, second O-ring 18, floating piston 19, third sealing ring 20, air storage cylinder 21, sealing gasket 22, air filling valve 23. Detailed Implementation

[0027] like Figure 1-4 As shown, a single-cylinder gas-filled magnetorheological fluid vibration damper includes a cylinder assembly, a piston assembly, a gas compensation assembly, and various sealing parts.

[0028] The cylinder assembly includes a sealing guide mechanism 2, a first sealing ring 3, a first O-ring 4a, a second O-ring 4b, a second sealing ring 5, a first permanent magnetic O-ring 6a, a second permanent magnetic O-ring 6b, a first piston ring 7, and a working cylinder 8.

[0029] The first O-ring 4a and the second O-ring 4b are used to seal the mating area between the outer wall of the guide mechanism 2 and the inner wall of the working cylinder 8; the first permanent magnetic O-ring 6a and the second permanent magnetic O-ring 6b are used to seal the mating gap between the guide mechanism 2 and the piston rod 1.

[0030] The first piston ring 7 is installed in the annular groove inside the sealing guide mechanism 2 to scrape off the ferromagnetic particles adsorbed on the surface of the piston rod 1 and assist the sealing ring in preventing leakage.

[0031] The first sealing ring 3 is located at the connection between the working cylinder 8 and the sealing guide mechanism 2 on the outside, to prevent external contaminants from entering the working cylinder 8.

[0032] The second sealing ring 5 is located at the connection between the working cylinder 8 and the sealing guide mechanism 2, preventing the internal magnetorheological fluid from leaking outward.

[0033] The sealing guide mechanism 2 is threaded to the end of the working cylinder 8. It is made of aluminum alloy, which has high thermal conductivity. It supports and guides the piston rod movement and integrates the sealing ring assembly.

[0034] The inner layer of the permanent magnetic O-ring uses high-hardness rare-earth permanent magnet materials, such as samarium cobalt alloy, which can withstand temperatures above 350℃. The surface is coated with chromium or tungsten carbide to improve wear resistance and reduce frictional heat generation. The outer rubber layer uses fluororubber or silicone rubber, with a temperature resistance range of 200~250℃ and excellent resistance to thermal oxidation.

[0035] The piston assembly includes a piston rod 1, an upper end cap 9, a piston sleeve 10, an iron core 11, a lower end cap 12, a first epoxy resin sealing ring 13a, a second epoxy resin sealing ring 13b, a first excitation coil 14a, a second excitation coil 14b, a wire-stopping steel ring 15, and a first O-ring seal 16. The piston assembly is coaxially arranged in the working cylinder 8.

[0036] The iron core 11 is provided with a first excitation coil 14a and a second excitation coil 14b. The first excitation coil 14a is sealed with a first epoxy resin sealing ring 13a, and the second excitation coil 14b is sealed with a second epoxy resin sealing ring 13b.

[0037] The iron core 11 has grooves at both the upper and lower ends. The upper end of the iron core 11 is interference-fitted with the boss at the lower end of the upper end cover 9 through the groove, and the lower end of the iron core 11 is interference-fitted with the boss at the upper end of the lower end cover 12 through the groove. Together with the rolled edge treatment of the piston sleeve 10, they form the piston head assembly.

[0038] The piston rod 1 has a groove that, through which a retaining wire steel ring 15 is inserted, forms an interference fit with the lower end cap 12, thereby fixing its relative position to the piston head assembly.

[0039] The first O-ring 16 is located at the gas compensation component interface to prevent inert gas leakage.

[0040] The gas compensation assembly includes a second piston ring 17, a second O-ring seal 18, a floating piston 19, a third sealing ring 20, a gas cylinder 21, a gasket 22, and a filling valve 23.

[0041] The gas storage cylinder 21 is connected to the working cylinder 8 and sealed by the third sealing ring 20. A floating piston 19 is provided on one side of the piston assembly. The inner diameter of the front end of the gas storage cylinder 21 changes in a step, and the part of it located inside the working cylinder 8 forms a boss with the inner wall of the working cylinder 8, which limits the movement of the floating piston 19.

[0042] An air filling valve 23 is provided at the bottom of the air storage cylinder 21. After the assembly of the magnetorheological damper is completed, inert gas is filled into the air storage cylinder 21 through the air filling valve 23 to the specified pressure.

[0043] The second O-ring 18 is used to seal the floating piston 19, isolating the gas from the magnetorheological fluid.

[0044] The second piston ring 17 is a positioning ring for the floating piston 19, which limits its displacement range and prevents the leakage of magnetorheological fluid.

[0045] like Figure 1 As shown, the iron core 11 has two sets of excitation coil slots, in which a first excitation coil 14a and a second excitation coil 14b are placed respectively. The first excitation coil 14a is sealed by a first epoxy resin sealing ring 13a; the second epoxy resin sealing ring 13b is sealed by the second excitation coil 14b. The magnetic field generated by the first excitation coil 14a and the second excitation coil 14b acts on the magnetorheological fluid in the damping channel, so as to realize the control of the damping performance of the magnetorheological fluid by controlling the current, thereby making the damping performance of the vibration damper controllable.

[0046] The damping channel is the annular gap between the outer wall of the piston sleeve 10 and the inner wall of the working cylinder 8. The magnetorheological fluid flows through this channel and is regulated by the magnetic field.

[0047] Working process of magnetorheological fluid vibration damper: Compression stroke: The piston head assembly moves to the right, the magnetorheological fluid is squeezed and flows to the left through the damping channel, the excitation coil is energized to generate a magnetic field, the ferromagnetic particles chain together to generate a magnetorheological effect, thereby increasing the damping force.

[0048] Recovery stroke: The piston head assembly moves to the left, and the magnetorheological fluid flows in the opposite direction, which can change the current magnitude and adjust the applied magnetic field, thereby controlling the damping effect again.

[0049] Gas compensation: The floating piston 19 moves left and right with the change of liquid volume, and the inert gas buffers the pressure fluctuation.

[0050] The outer surface of the piston head assembly is plated with chromium or tungsten carbide coating to improve wear resistance and reduce frictional heat generation.

[0051] Working principle and process: like Figure 5 As shown, the sealing of the sealing guide mechanism 2 consists of a first permanent magnetic O-ring 6a and a second permanent magnetic O-ring 6b, both of which are magnetic. Firstly, the second permanent magnetic O-ring 6b attracts ferromagnetic particles in the magnetorheological fluid. Figure 5Deposition occurs at position A, preventing the passage of any unattracted ferromagnetic particles and achieving a seal. The first piston ring 7 then cleans up any remaining ferromagnetic particles leaking from position A, preventing wear on other parts and also preventing leakage of the magnetorheological fluid. Finally, the first permanent magnetic O-ring 6a attracts a small number of ferromagnetic particles passing through the first piston ring 7 and the second permanent magnetic O-ring 6b, achieving a seal again. It should be noted that, through careful calculation, the magnetism of the permanent magnetic O-ring is precisely sufficient to attract a sufficient amount of ferromagnetic particles without significantly reducing the mass fraction of ferromagnetic particles in the magnetorheological fluid or causing sedimentation. It should also be noted that the number of permanent magnetic O-rings can be increased or decreased by adding or removing annular grooves on the inner wall of the sealing guide mechanism 2, depending on the working environment and intensity of the magnetorheological damper, to meet sealing requirements under different conditions.

Claims

1. A magnetorheological vibration damper using a permanent magnetic sealing ring, characterized in that: Includes cylinder assembly, piston assembly, and gas compensation assembly; The cylinder assembly includes a working cylinder (8), one end of which is sealed by a sealing guide mechanism (2) and sealed with the piston rod (1); the other end of the working cylinder (8) is provided with a gas compensation assembly; The piston assembly includes a piston rod (1), which is connected to the piston head assembly; the piston head assembly includes a piston sleeve (10), an iron core (11) is arranged inside the piston sleeve (10), and the left and right ends of the iron core (11) are correspondingly engaged with the upper end cap (9) and the lower end cap (12) and combined with the piston sleeve (10) to form a whole; an excitation coil is provided inside the piston sleeve (10) and outside the iron core (11), and the excitation coil controls the damping performance of the magnetorheological fluid; The gas compensation assembly includes a gas storage cylinder (21), one side of which is connected to the working cylinder (8) and the other side is equipped with a gas filling valve (23). The gas storage cylinder (21) is filled with inert gas. A floating piston (19) is arranged in the working cylinder (8) near the gas storage cylinder (21). The floating piston (19) moves in a reciprocating linear motion under the action of the gas.

2. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The piston rod (1) has an axially penetrating wire hole at its center. Wires are arranged in the wire hole and sealed with epoxy resin.

3. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The sealing guide mechanism (2) includes a guide body, the outer side of which is sealed to the working cylinder (8) by an O-ring; the inner side of the guide body is sealed to the piston rod (1) by a permanent magnetic O-ring.

4. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 3, characterized in that: The inner wall of the sealing guide mechanism (2) is provided with multiple sets of annular grooves, and a permanent magnetic O-ring is installed in each annular groove. The number of permanent magnetic O-rings matches the working environment of the magnetorheological damper.

5. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 3, characterized in that: A first piston ring (7) is installed on the inner side of the guide body, and a first sealing ring (3) and a second sealing ring (5) are installed on the front and rear sides of the guide body, respectively.

6. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The connection between the working cylinder (8) and the gas storage cylinder (21) is sealed by a third sealing ring (20).

7. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The portion of the gas storage cylinder (21) located inside the working cylinder (8) forms a boss with the side wall of the working cylinder (8), and the boss limits the position of the floating piston (19) away from the piston head assembly.

8. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The middle section of the outer wall of the piston sleeve (10) protrudes outward, and the middle section of the outer wall of the piston sleeve (10) is attached to the working cylinder (8) and guides the piston head assembly to move left and right.

9. A magnetorheological vibration damper using a permanent magnetic sealing ring according to claim 1, characterized in that: The excitation coil is sealed by an epoxy resin sealing ring.

10. A method for sealing using a permanent magnetic sealing ring magnetorheological vibration damper according to any one of claims 1-9, characterized in that, Includes the following steps: Step 1: First, a set of permanent magnetic O-rings closest to the magnetorheological fluid attracts ferromagnetic particles in the magnetorheological fluid to deposit at the installation position of the permanent magnetic O-rings, thereby blocking the passage of other unattracted ferromagnetic particles to achieve the sealing purpose. Step 2: Then, the first piston ring (7) cleans up the small amount of ferromagnetic particles leaking from the installation position of the permanent magnet O-ring; at the same time, the first piston ring 7 prevents the leakage of magnetorheological fluid; Step 3: Finally, the other permanent magnetic O-rings on the side away from the magnetorheological fluid can attract a very small number of ferromagnetic particles passing through the first piston ring (7) to achieve the purpose of sealing.

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