Composite sealed magnetorheological damper

Abstract

The utility model aims to provide a composite sealed magnetorheological damper. The composite sealed magnetorheological damper comprises a cylinder body, a left end cover, a sleeve, a piston rod, a left pole shoe, a right pole shoe, a permanent magnet ring, a piston assembly and a guide ring, the left end of the cylinder body is sealed by the left end cover and filled with magnetorheological fluid, and the sleeve is arranged at the left end in the cylinder body; the circular ring surface of the left end of the sleeve is hermetically assembled with the inner side wall of the left end cover; a guide ring, a left pole shoe, a permanent magnet ring and a right pole shoe are sequentially arranged in the sleeve from the left end to the right end, and the right end of the piston rod extends into the cylinder body from the left end cover; the outer circle face of the guide ring makes contact with the inner circle face of the sleeve, the right end face of the guide ring makes contact with the inner wall of the right side of the sleeve, and the guide ring and the piston rod form a sealed sliding structure. The piston rod and the right side wall of the sleeve also form a sealed sliding structure; the left pole shoe, the right pole shoe and the permanent magnet ring are arranged on the inner wall of the sleeve and are not in contact with the piston rod; the right end of the piston rod is provided with a piston assembly. The piston rod can be efficiently sealed.

Description

Technical Field

[0001] This utility model relates to the field of vibration reduction in mechanical engineering, and in particular to a composite sealed magnetorheological damper. Background Technology

[0002] Magnetorheological dampers are advanced vibration reduction devices based on smart materials technology. Their core lies in utilizing the unique physical properties of magnetorheological fluids to achieve rapid and precise adjustment of damping force. The magnetorheological damper is controlled by a piston assembly integrating an electromagnetic coil. When the piston reciprocates due to external environmental vibrations, the magnetorheological fluid flows through a pre-set damping channel. Adjusting the coil current intensity changes the magnetic field strength, thereby controlling the fluid's flow resistance. In traditional magnetorheological dampers, the damping channel is typically a linear structure, resulting in a limited dynamic adjustment range and restricting its application scenarios. Furthermore, the damper end caps usually use ordinary sealing rings, posing a risk of magnetorheological fluid leakage during the piston rod's reciprocating motion. Therefore, magnetorheological dampers with a large dynamic adjustment range and achieving efficient sealing and guidance coordination are currently a research hotspot.

[0003] A patent search was conducted, comparing the magnetorheological dampers in Document 1 (Publication No. CN222315780U) and Document 2 (Publication No. CN221683464U). The former provides a channel-adjustable, built-in valve-type magnetorheological vibration damper. This damper can open or close the DC channel by rotating a lever linkage, thereby changing the number of fluid channels and thus altering the zero-field damping force and dynamic adjustable range of the damper. However, expanding the damping adjustment range through mechanical means sacrifices the original advantages of magnetorheological technology: rapid response, high reliability, and low maintenance. A trade-off must be made between mechanical complexity, dynamic performance, and long-term durability when pursuing a larger adjustable range. Furthermore, this damper does not consider the need for dynamic sealing of rotating components; however, the magnetorheological fluid contains tiny particles, which can easily accelerate the wear of seals, potentially leading to leakage with long-term use. The latter provides a magnetorheological damper with high damping force density. This damper features a damping channel within its cylinder for the magnetorheological fluid to flow through. A piston assembly extends beyond the cylinder and is equipped with a lifting ring. A floating piston is slidably fitted between the cylinder bottom and the piston assembly. This damper requires fewer machined parts in its piston head and achieves high damping force density. However, the simplified piston head may not accommodate complex magnetic circuit structures or multi-stage damping channels, leading to uneven magnetic field distribution and a single fluid flow path, ultimately limiting the adjustable range of the damping force. Furthermore, the stress points are concentrated on a few components, making them susceptible to wear, deformation, or even breakage due to fatigue or particle erosion after prolonged use. Therefore, there is an urgent need for a magnetorheological damper with a wide dynamic adjustment range, broad application scenarios, and good reciprocating sealing performance. Utility Model Content

[0004] This invention aims to provide a composite sealed magnetorheological damper that can achieve efficient sealing, effectively avoid problems such as easy failure of reciprocating seals at the piston rod, and the preferred solution can also solve the problems of single width of damping channel and narrow dynamic adjustment range of ordinary magnetorheological dampers.

[0005] The technical solution of this utility model is as follows:

[0006] The composite sealed magnetorheological damper includes a cylinder, a left end cover, a sleeve, a piston rod, a left pole shoe, a right pole shoe, a permanent magnet ring, a piston assembly, and a guide ring.

[0007] The left end of the cylinder is sealed by a left end cap, which is filled with magnetorheological fluid. A sleeve is located at the left end of the cylinder. The left end of the sleeve is an open structure, and the annular surface of the left end of the sleeve is sealed and assembled with the inner wall of the left end cap.

[0008] From left to right inside the sleeve, a guide ring, a left pole shoe, a permanent magnet ring, and a right pole shoe are arranged in sequence. The right end of the piston rod passes through the guide ring, left pole shoe, permanent magnet ring, right pole shoe, and sleeve from the left end cover and extends into the cylinder body. The outer circular surface of the guide ring contacts the inner circular surface of the sleeve, and the right end face of the guide ring contacts the right inner wall of the sleeve, forming a sealed sliding structure with the piston rod. The piston rod also forms a sealed sliding structure with the right side wall of the sleeve. The left pole shoe, right pole shoe, and permanent magnet ring are all located on the inner wall of the sleeve and do not contact the piston rod.

[0009] A piston assembly is mounted on the right end of the piston rod.

[0010] The inner surface of the guide ring is a stepped ring surface. There is a gap between the inner surface of the guide ring and the outer surface of the piston rod. The stepped ring sealing ring, sealing ring A, and sealing ring B are arranged sequentially from left to right in the gap.

[0011] The left end face and inner circular surface of the left pole shoe are respectively provided with pole teeth A. Pole teeth A correspond to the inner wall of the left end cover and the outer circular surface of the piston rod but do not contact each other. Magnetorheological fluid is provided between pole teeth A, the right side wall of the guide ring and the outer circular surface of the piston rod.

[0012] The right end face and inner circular surface of the right pole shoe are respectively provided with pole teeth B. The pole teeth B correspond to the guide ring and the outer circular surface of the piston rod but do not contact each other. Magnetorheological fluid is provided between the pole teeth B, the right inner wall of the sleeve, and the outer circular surface of the piston rod.

[0013] Positioning sleeve A and positioning sleeve B are respectively provided on the inner wall of the sleeve by interference fit; positioning sleeve C is fitted on the outer circular surface of the piston rod by interference fit.

[0014] The positioning sleeve A contacts the left side wall of the guide ring and the left end face of the left pole shoe, respectively; the positioning sleeve C contacts the left side wall of the guide ring and the left end face of the left pole shoe, respectively; the pole tooth B on the right end face of the right pole shoe is located in the area between the inner circular surface of the positioning sleeve A and the outer circular surface of the positioning sleeve C.

[0015] The positioning sleeve B contacts the right end face of the right pole shoe and the left end face of the sleeve, respectively; the pole tooth B on the right end face of the right pole shoe is located in the area between the inner circular surface of the positioning sleeve B and the outer circular surface of the piston rod.

[0016] The left end cap and the right side wall of the sleeve are respectively provided with piston rod holes. The piston rod passes through the piston rod holes with clearance fit. The piston rod holes are respectively provided with sealing ring grooves C, and sealing rings C are provided inside them.

[0017] The piston assembly includes an excitation coil, an inner piston, an outer piston ring, an upper piston cap, and a lower piston cap. The upper end face of the inner piston is encapsulated by the upper piston cap, the lower end face by the lower piston cap, and the outer circular surface by the outer piston ring. The outer piston ring is sealed to the lower piston cap and the upper piston cap. The outer circular surface of the inner piston is provided with one or more coil slots at intervals, and an excitation coil is placed in the coil slot. The surface of the excitation coil is coated with sealant. A damping channel is formed between the outer piston ring and the outer circular surface of the inner piston. The upper piston cap and the lower piston cap are provided with two or more sets of connecting holes corresponding to the damping channel at intervals.

[0018] The right end of the piston rod passes through the center of the piston upper end cap and is fixedly connected to the inner piston.

[0019] The piston outer ring has a concave ring on the right side, forming a damping channel with a larger diameter between the concave ring and the outer circular surface of the inner piston.

[0020] The composite sealed magnetorheological damper also includes a floating piston and a right end cap. The right end of the cylinder is sealed by the right end cap. A floating piston is provided on the right side of the cylinder. The floating piston can slide relative to the cylinder. A sealing ring groove is provided on the outer circular surface of the floating piston, and a sealing ring is provided inside it. The cylinder on the left side of the floating piston is filled with magnetorheological fluid, and the cylinder between the right end face of the floating piston and the right end cap is filled with nitrogen.

[0021] The right end cover is equipped with a one-way inflation valve, which is connected to a nitrogen source and is used to fill the space between the right end cover and the floating piston with nitrogen.

[0022] A connecting ring is fixedly installed on the right end face of the right end cover.

[0023] The inner circular surface of the sleeve is provided with one or more sealing ring grooves D, and each sealing ring groove D is provided with a sealing ring D.

[0024] The beneficial effects of this utility model are as follows:

[0025] This invention addresses the problem of reciprocating seal failure at the piston rod of ordinary magnetorheological dampers. The damper innovatively adopts an integrated sealing-guiding design. By adding a sleeve, pole shoe, permanent magnet, and guide ring to the end cap side, and embedding a double sealing structure within the guide ring, multiple performance improvements are achieved. This design has three significant advantages: First, the magnetorheological sealing structure is close to the cylinder interior. If internal magnetorheological fluid leaks, it can be used to replenish the magnetorheological medium in the sealing device, increasing the damper's sealing performance while reusing leaked material. Second, the guide ring can precisely constrain the piston rod's movement trajectory, reducing lateral offset or radial wobble and significantly improving motion stability. Finally, integrating the guiding sealing structure inside the magnetorheological sealing device simplifies the end cap structure and allows the seal to dynamically conform to the piston rod surface, reducing magnetorheological fluid leakage to an acceptable range even under high-speed reciprocating motion.

[0026] This invention innovatively employs a variable-width damping channel design, improving the traditional single-width damping channel into a variable-width damping channel composed of combinations of damping channels with different widths. This design has three significant advantages: First, the step-like variation in channel width promotes a gradient distribution of the magnetic field, which, combined with the coordinated control of dual coils, expands the dynamic adjustable range of the damper and achieves more precise multi-level damping adjustment; second, the segmented structure ensures rapid flow of the magnetorheological fluid through the wide damping channel segment, shortening the damper's response time; at the same time, the rational design of the narrow damping channel segment ensures sufficient damping force and, due to its combination with the wide channel, effectively reduces the risk of blockage that is common in traditional single narrow channels.

[0027] This invention proposes a magnetorheological damper with a variable gap flow channel and composite seal. Through innovative variable-width damping channel design and integrated sealing-guiding design, it effectively solves key problems of traditional magnetorheological dampers, such as limited dynamic adjustment range, insufficient response speed, and poor sealing reliability. This design not only achieves a wider adjustable damping range and more precise multi-stage control, but also significantly improves the damper's response speed, anti-clogging ability, and long-term sealing performance, possessing significant engineering application value. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the composite sealed magnetorheological damper of Example 1;

[0029] Figure 2 This is a schematic diagram of the left end cap and sleeve structure of Example 1;

[0030] The names and numbers of the parts in the diagram are as follows:

[0031] 1-Cylinder body, 2-Left end cover, 3-Sleeve, 4-Piston rod, 5-Left pole shoe, 6-Right pole shoe, 7-Permanent magnet ring, 8-Guide ring, 9-Sealing ring D, 10-Pole tooth A, 11-Pole tooth B, 12-Positioning sleeve A, 13-Positioning sleeve B, 14-Positioning sleeve C, 15-Excitation coil, 16-Inner piston, 17-Piston outer ring, 18-Piston upper end cover, 19-Piston lower end cover, 20-Floating piston, 21-Right end cover, 22-Connecting ring, 23-Stepped ring sealing ring, 24-Sealing ring A, 25-Sealing ring B, 26-Sealing ring C, 27-Concave ring. Detailed Implementation

[0032] The following description, in conjunction with the accompanying drawings, details the implementation methods and embodiments of this utility model and their working processes.

[0033] like Figure 1 and 2 As shown, the composite sealed magnetorheological damper includes a cylinder body 1, a left end cover 2, a sleeve 3, a piston rod 4, a left pole shoe 5, a right pole shoe 6, a permanent magnet ring 7, a piston assembly, and a guide ring 8.

[0034] The left end of the cylinder 1 is sealed by the left end cap 2 and is filled with magnetorheological fluid. The sleeve 3 is located inside the left end of the cylinder 1. The inner circular surface of the sleeve 3 has one or more sealing ring grooves D, and each sealing ring D9 is provided in the sealing ring groove D. The left end of the sleeve 3 is an open structure, and the annular surface of the left end of the sleeve 3 is sealed and assembled with the inner side wall of the left end cap 2.

[0035] From left to right inside the sleeve 3, a guide ring 8, a left pole shoe 5, a permanent magnet ring 7, and a right pole shoe 6 are arranged sequentially. The right end of the piston rod 4 passes through the guide ring 8, left pole shoe 5, permanent magnet ring 7, right pole shoe 6, and sleeve 3 from the left end cover 2 and extends into the cylinder body 1. The outer circular surface of the guide ring 8 contacts the inner circular surface of the sleeve 3, and the right end face of the guide ring 8 contacts the right inner wall of the sleeve 3. The guide ring 8 and the piston rod 4 form a sealed sliding structure. The piston rod 4 and the right side wall of the sleeve 3 also form a sealed sliding structure. The left pole shoe 5, right pole shoe 6, and permanent magnet ring 7 are all located on the inner wall of the sleeve 3 and do not contact the piston rod 4.

[0036] The inner surface of the guide ring 8 is a stepped ring surface. There is a gap between the inner surface of the guide ring 8 and the outer surface of the piston rod 4. The stepped ring sealing ring 23, sealing ring A24 and sealing ring B25 are arranged in the gap from left to right.

[0037] The left end face and inner circular surface of the left pole shoe 5 are respectively provided with pole teeth A10. The pole teeth A10 correspond to the inner wall of the left end cover 2 and the outer circular surface of the piston rod 4 but do not contact each other. Magnetorheological fluid is provided between the pole teeth A10, the right side wall of the guide ring 8 and the outer circular surface of the piston rod 4.

[0038] The right end face and inner circular face of the right pole shoe 6 are respectively provided with pole teeth B11. The pole teeth B11 correspond to the guide ring 8 and the outer circular face of the piston rod 4 but do not contact each other. Magnetorheological fluid is provided between the pole teeth B11 and the right inner wall of the sleeve 3 and the outer circular face of the piston rod 4.

[0039] Positioning sleeves A12 and B13 are respectively provided on the inner wall of the sleeve 3 by interference fit; positioning sleeve C14 is fitted on the outer circumference of the piston rod 4 by interference fit.

[0040] The positioning sleeve A12 contacts the left side wall of the guide ring 8 and the left end face of the left pole shoe 5 respectively, and the positioning sleeve C14 contacts the left side wall of the guide ring 8 and the left end face of the left pole shoe 5 respectively; the pole tooth B11 on the right end face of the right pole shoe 6 is located in the area between the inner circular surface of the positioning sleeve A12 and the outer circular surface of the positioning sleeve C14.

[0041] The positioning sleeve B13 contacts the right end face of the right pole shoe 6 and the left end face of the sleeve 3 respectively; the pole tooth B11 on the right end face of the right pole shoe 6 is located in the area between the inner circular surface of the positioning sleeve B13 and the outer circular surface of the piston rod 4.

[0042] The left end cap 2 and the right side wall of the sleeve 3 are respectively provided with piston rod holes. The piston rod 4 passes through the piston rod hole based on clearance fit. The piston rod hole is provided with sealing ring groove C, and sealing ring C26 is provided inside it.

[0043] A piston assembly is mounted on the right end of the piston rod 4. The piston assembly includes an excitation coil 15, an inner piston 16, an outer piston ring 17, an upper piston cap 18, and a lower piston cap 19. The upper end face of the inner piston 16 is encapsulated by the upper piston cap 18, the lower end face by the lower piston cap 19, and the outer circular surface by the outer piston ring 17. The outer piston ring 17 is sealed to the lower piston cap 19 and the upper piston cap 18. One or more coil slots are spaced apart on the outer circular surface of the inner piston 16, and an excitation coil 15 is placed in the coil slot. The surface of the excitation coil 15 is coated with sealant. A damping channel is formed between the outer piston ring 17 and the outer circular surface of the inner piston 16. Two or more sets of connecting holes corresponding to the damping channel are spaced apart on the upper piston cap 18 and the lower piston cap 19. The right end of the piston rod 4 passes through the center of the upper piston cap 18 and is fixedly connected to the inner piston 16. A concave ring 27 is provided on the right side of the piston outer ring 17, and a damping channel with a larger diameter is formed between the concave ring 27 and the outer circular surface of the inner piston 16.

[0044] The composite sealed magnetorheological damper further includes a floating piston 20 and a right end cap 21. The right end of the cylinder 1 is sealed by the right end cap 21. The floating piston 20 is installed on the right side inside the cylinder 1. The floating piston 20 can slide relative to the cylinder 1. A sealing ring groove is provided on the outer circumference of the floating piston 20, and a sealing ring is installed inside it. The cylinder 1 on the left side of the floating piston 20 is filled with magnetorheological fluid, and the cylinder 1 between the right end face of the floating piston 20 and the right end cap 21 is filled with nitrogen. A one-way inflation valve is provided on the right end cap 21. The one-way inflation valve is connected to a nitrogen source and is used to fill the space between the right end cap 21 and the floating piston 20 with nitrogen. A connecting ring 22 is fixedly installed on the right end face of the right end cap 21.

Claims

1. A composite sealed magnetorheological damper, comprising a cylinder body (1), a left end cap (2), a sleeve (3), a piston rod (4), a left pole shoe (5), a right pole shoe (6), a permanent magnet ring (7), a piston assembly, and a guide ring (8), characterized in that: The left end of the cylinder (1) is sealed by the left end cap (2), which is filled with magnetorheological fluid. The sleeve (3) is located at the left end of the cylinder (1). The left end of the sleeve (3) is an open structure, and the annular surface of the left end of the sleeve (3) is sealed and assembled with the inner side wall of the left end cap (2). From left to right inside the sleeve (3), a guide ring (8), a left pole shoe (5), a permanent magnet ring (7), and a right pole shoe (6) are arranged in sequence. The right end of the piston rod (4) passes through the guide ring (8), the left pole shoe (5), the permanent magnet ring (7), the right pole shoe (6), and the sleeve (3) from the left end cover (2) and extends into the cylinder (1). The outer circular surface of the guide ring (8) contacts the inner circular surface of the sleeve (3), and the right end face of the guide ring (8) contacts the right inner wall of the sleeve (3). The guide ring (8) and the piston rod (4) form a sealed sliding structure. The piston rod (4) and the right side wall of the sleeve (3) also form a sealed sliding structure. The left pole shoe (5), the right pole shoe (6), and the permanent magnet ring (7) are all located on the inner wall of the sleeve (3) and do not contact the piston rod (4). A piston assembly is installed on the right end of the piston rod (4).

2. The composite sealed magnetorheological damper of claim 1, wherein: The inner surface of the guide ring (8) is a stepped ring surface. There is a gap between the inner surface of the guide ring (8) and the outer surface of the piston rod (4). The stepped ring sealing ring (23), sealing ring A (24), and sealing ring B (25) are arranged in the gap from left to right.

3. The composite sealed magnetorheological damper according to claim 2, characterized in that: The left end face and inner circular face of the left pole shoe (5) are respectively provided with pole teeth A (10). The pole teeth A (10) correspond to the inner wall of the left end cover (2) and the outer circular face of the piston rod (4) but do not contact each other. Magnetorheological fluid is provided between the pole teeth A (10), the right side wall of the guide ring (8) and the outer circular face of the piston rod (4). The right end face and inner circular face of the right pole shoe (6) are respectively provided with pole teeth B (11). The pole teeth B (11), the guide ring (8), and the outer circular face of the piston rod (4) correspond to each other but do not contact each other. Magnetorheological fluid is provided between the pole teeth B (11), the right inner wall of the sleeve (3), and the outer circular face of the piston rod (4).

4. The composite sealed magnetorheological damper of claim 3, wherein: Positioning sleeve A (12) and positioning sleeve B (13) are respectively provided on the inner wall of the sleeve (3) by interference fit; positioning sleeve C (14) is fitted on the outer circumference of the piston rod (4) by interference fit. The positioning sleeve A (12) contacts the left side wall of the guide ring (8) and the left end face of the left pole shoe (5) respectively; the positioning sleeve C (14) contacts the left side wall of the guide ring (8) and the left end face of the left pole shoe (5) respectively; the pole tooth B (11) on the right end face of the right pole shoe (6) is located in the area between the inner circle of the positioning sleeve A (12) and the outer circle of the positioning sleeve C (14); The positioning sleeve B (13) contacts the right end face of the right pole shoe (6) and the left end face of the sleeve (3) respectively; the pole tooth B (11) on the right end face of the right pole shoe (6) is located in the area between the inner circle of the positioning sleeve B (13) and the outer circle of the piston rod (4).

5. The composite sealed magnetorheological damper of claim 1, wherein: The left end cap (2) and the right side wall of the sleeve (3) are respectively provided with piston rod holes. The piston rod (4) passes through the piston rod hole based on clearance fit. The piston rod hole is provided with sealing ring groove C, and sealing ring C (26) is provided inside.

6. The composite sealed magnetorheological damper according to claim 1, characterized in that: The piston assembly includes an excitation coil (15), an inner piston (16), an outer piston ring (17), an upper piston cap (18), and a lower piston cap (19). The upper end face of the inner piston (16) is encapsulated by the upper piston cap (18), the lower end face is encapsulated by the lower piston cap (19), and the outer circular surface is encapsulated by the outer piston ring (17). The outer piston ring (17) is sealed to the lower piston cap (19) and the upper piston cap (18). The outer circular surface of the inner piston (16) is provided with one or more coil slots at intervals. An excitation coil (15) is provided in the coil slots. The surface of the excitation coil (15) is coated with sealant. A damping channel is formed between the outer piston ring (17) and the outer circular surface of the inner piston (16). The upper piston cap (18) and the lower piston cap (19) are provided with two or more sets of connecting holes corresponding to the damping channel at intervals. The right end of the piston rod (4) passes through the center of the piston upper end cap (18) and is fixedly connected to the inner piston (16).

7. The composite sealed magnetorheological damper of claim 6, wherein: The piston outer ring (17) has a concave ring (27) on the right side, and a damping channel with a larger diameter is formed between the concave ring (27) and the outer circular surface of the inner piston (16).

8. The composite sealed magnetorheological damper of claim 1, wherein: It also includes a floating piston (20) and a right end cap (21). The right end of the cylinder (1) is sealed by the right end cap (21). A floating piston (20) is provided on the right side inside the cylinder (1). The floating piston (20) can slide relative to the cylinder (1). A sealing ring groove is provided on the outer circular surface of the floating piston (20), and a sealing ring is provided inside it. The cylinder (1) on the left side of the floating piston (20) is filled with magnetorheological fluid, and the cylinder (1) between the right end face of the floating piston (20) and the right end cap (21) is filled with nitrogen. The right end cover (21) is provided with a one-way inflation valve, which is connected to a nitrogen source and is used to fill the space between the right end cover (21) and the floating piston (20) with nitrogen.

9. The composite sealed magnetorheological damper of claim 8, wherein: A connecting ring (22) is fixedly installed on the right end face of the right end cover (21).

10. The composite sealed magnetorheological damper of claim 1, wherein: The sleeve (3) has one or more sealing ring grooves D on its inner circular surface, and each sealing ring groove D is provided with a sealing ring D (9).

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