A magnetorheological damper with a semi-circular toroidal winding frame

Abstract

This invention proposes a magnetorheological damper with a semi-circular annular winding frame. The annular gap formed between the piston head and the inner surface of the cylinder constitutes a fluid flow channel. By designing the piston head as a rotating body with a semi-circular cross-section, the magnetic field lines at the piston head are guided into a semi-circular shape. This increases the magnetic field at the effective damping gap without increasing the overall size of the damper, effectively improving the output damping force and the adjustable range of the damping force. Simultaneously, the magnetic conductive material is made of silicon steel, while the magnetic shielding material is made of high-density aluminum alloy; the significant difference in density between the two materials effectively reduces the weight of the magnetorheological damper. When the excitation coil is energized, the magnetic field lines generated by electromagnetic induction form a semi-circular magnetic field line at the piston head. This line passes through the left side of the piston head, the axial annular damping gap A, to the cylinder, and then through the right side of the winding frame, the axial annular damping gap B, to the piston head, forming a closed loop.

Description

Technical Field

[0001] This invention relates to a magnetorheological damper, and more particularly to a magnetorheological damper with a semi-circular toroidal winding frame. Background Technology

[0002] Magnetorheological dampers are a new type of intelligent damping device that uses magnetorheological fluid as the working medium. Based on the magnetorheological effect, magnetorheological dampers have advantages such as simple structure, small size, low energy consumption, and fast response. Due to their adjustable damping characteristics, they are widely used in vibration control fields such as automobiles, shock absorbers, and prosthetics.

[0003] In high-output applications, magnetorheological dampers often employ extended internal fluid channels during the design process to increase output damping force. However, this method frequently results in excessively large damper volumes. Furthermore, the narrow gaps in the flow channels make the excessively long channels prone to blockage, affecting performance. Increased volume also leads to higher magnetic reluctance, consequently impacting the magnetic field strength at the effective damping gap. Therefore, to further enhance the output damping force of the magnetorheological damper, it is necessary to increase the magnetic field at the effective damping gap, ensuring that most of the magnetic field lines pass through it.

[0004] Based on this, the present invention proposes a magnetorheological damper with a circular winding frame, which increases the magnetic field at the effective damping gap by changing the magnetic field lines, while also having the advantage of light weight. Summary of the Invention

[0005] To overcome the shortcomings of the magnetorheological dampers described in the background art and meet the requirements of engineering applications, this invention proposes a magnetorheological damper with a semi-circular annular winding frame. The annular gap formed between the annular piston head and the inner surface of the cylinder constitutes a fluid flow channel. By designing the piston head, made of magnetically conductive material, as a rotating body with a semi-circular cross-section, and to prevent magnetic leakage, a piston rod made of magnetically insulating material is fully fitted to the inner surface of the piston head, guiding the magnetic lines of force at the piston head in a semi-circular shape. This increases the magnetic field at the effective damping gap without increasing the overall size of the damper, effectively improving the output damping force and the adjustable range of the damping force. Simultaneously, the magnetically conductive material is made of silicon steel, and the magnetically insulating material is made of aluminum alloy; the significant difference in density between the two materials effectively reduces the weight of the magnetorheological damper. When the excitation coil is energized, the magnetic field lines generated by electromagnetic induction form a semi-circular magnetic field line at the piston head. This line passes through the left side of the piston head, the axial circular damping gap A, to the cylinder body, and then through the right side of the winding frame, the axial circular damping gap B, to the piston head, forming a closed loop. Under the influence of the magnetic field, the magnetorheological fluid generates a magnetorheological effect in the fluid flow channel, increasing the shear yield stress of the magnetorheological fluid and generating a damping force that hinders the movement of the piston rod. By changing the magnitude of the current flowing through the excitation coil, the output damping force of the damper can be changed in real time.

[0006] The technical solution adopted by the present invention to solve its technical problem includes: a left piston rod (1), an oil injection screw (2), a screw (3), a left end cap (4), a damper cylinder (5), a piston head (6), an excitation coil (7), a magnetorheological fluid (8), a right end cap (9), an end cover (10), and a right piston rod (11); the left piston rod (1) is processed into a stepped shape, and external threads are processed on the outer circumferential surfaces of its left and right ends, and a quarter-circular arc surface (101) is processed on the right side of the external thread on the right end; the left end cap (4) of the damper is fixedly connected to the damper cylinder (5) by screws (3) and sealed by a sealing ring; the left end cap (4) of the damper is processed with a right central through hole, and the left piston rod (1) is clearance-fitted with the inner surface of the central through hole of the left end cap (4) of the damper and sealed by a sealing ring; an inner semi-circular surface (103) is processed at the center of the piston head and is connected to the left piston rod (1). The right end has a quarter-circular arc surface (101) for mating; the right piston rod (2) is machined into a stepped shape, and the left end has a quarter-circular arc surface (102) for mating with the center arc surface (103) of the piston head. A threaded hole is machined on the left end face for mating with the external thread on the right end of the left piston rod to clamp the piston head; the inner surface of the damper cylinder (5) and the outer circular channel of the piston head (6) form damping gaps A and B; the excitation coil (7) is evenly wound on the piston head (6); the left side of the piston head (6) and the left piston rod (1) are machined with right lead holes, and the lead wire of the excitation coil (7) is led out through the lead holes; a protective boss (201) is machined on the left piston rod (1) to prevent the left end cover (4) of the damper from cutting the lead wire of the excitation coil (7); the piston head (6) and the damper cylinder (5) are made of magnetic silicon steel, and the rest of the parts are made of non-magnetic aluminum alloy.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] (1) The magnetorheological damper of the present invention, by processing the piston head into a semi-circular shape, guides the magnetic field lines to pass through the damping gap in a circular shape, thereby increasing the magnetic field strength at the piston head gap; it can effectively improve the output damping force and adjustable range of the damper without changing the external dimensions.

[0009] (2) The magnetorheological damper of the present invention uses aluminum alloy to make an outer arc profile at one end of the left and right piston rods respectively, which reduces the magnetic leakage phenomenon of the magnetorheological damper; it can further increase the utilization rate of the magnetic field and reduce the magnetic field loss at the damping gap.

[0010] (3) The magnetorheological damper of the present invention greatly reduces the weight of the magnetorheological damper by using a circular piston head and supplementing it with a material with a density much lower than that of magnetic silicon steel.

[0011] (4) The present invention has a compact structure and occupies little space. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention.

[0013] Figure 2 This is a cross-sectional view of the piston head of the present invention.

[0014] Figure 3 This is a cross-sectional view of the left piston rod of the present invention.

[0015] Figure 4 This is a cross-sectional view of the right piston rod of the present invention.

[0016] Figure 5 This is a magnetic field line distribution diagram of the present invention.

[0017] Explanation of reference numerals in the attached figures:

[0018] 1-Left piston rod, 2-Oil injection screw, 3-Screw, 4-Left end cap, 5-Damper cylinder body, 6-Piston head, 7-Excitation coil, 8-Magnetorheological fluid, 9-Right end cap, 10-End cover, 11-Right piston rod. Detailed Implementation

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

[0020] Figure 1 The diagram shown is a schematic representation of the structure of this invention. Left piston rod (1), oil filler screw (2), screw (3), left end cap (4), damper cylinder (5), piston head (6), excitation coil (7), magnetorheological fluid (8), right end cap (9), end cover (10), right piston rod (11).

[0021] Figure 2 This is a cross-sectional view of the piston head. The center hole inside the piston head (6) is machined into an arc surface (103) and an arc winding surface (104).

[0022] Figure 3 This is a cross-sectional view of the left piston rod of the present invention. The left piston rod (3) is machined to form an arc surface (101) and a protective boss (302).

[0023] Figure 4 This is a cross-sectional view of the right piston rod of the present invention. The right piston rod (11) has a threaded hole and an arc surface (102) machined inside.

[0024] Figure 5 This is a magnetic field distribution diagram of the present invention. The magnetic field lines generated by the excitation coil (7) start from the piston head (6), pass through the damping gap A to reach the damper cylinder (5), and then return to the piston head (6) through the damping gap B, forming a closed loop at the piston head (6).

[0025] The working principle of this invention is as follows:

[0026] The annular gaps between the outer circumferential surface of the piston head and the inner circumferential surface of the damper cylinder constitute damping gaps A and B. The piston head, damper cylinder, damping gaps A and B form a closed magnetic field loop. When current flows through the excitation coil, a magnetic field perpendicular to the fluid flow direction is formed within the annular gap. After the magnetorheological fluid flows through fluid flow channel A, it exhibits a magnetorheological effect, increasing shear stress. Under external excitation, the left piston rod 1 moves, causing the piston head 6 and right piston rod 11 to move. Due to the increased shear stress, a large output damping force is generated, hindering the movement of the left piston rod 1, piston head 6, and right piston rod 11, thus achieving a damping and vibration reduction effect. Changing the magnitude of the current flowing through the excitation coil 7 changes the output damping force.

Claims

1. A magnetorheological damper with a semi-circular annular winding frame, characterized in that, include: Left piston rod, oil filler screw, screw, left end cap, damper cylinder, piston head, excitation coil, magnetorheological fluid, right end cap, end cover, and right piston rod; The left end cover is fixedly connected to the damper cylinder body by screws and sealed by a sealing ring; the left end cover has a central through hole, the left piston rod is clearance-fitted with the inner surface of the central through hole of the left end cover, and sealed by a sealing ring; The left piston rod is machined into a stepped shape, with external threads on the outer circumference surfaces of both ends. A quarter-circle arc surface is machined on the right side of the external thread at the right end. The right piston rod is machined into a stepped shape, with a quarter-circular outer arc surface machined on its left end. A threaded hole is machined on the left end face to mate with the external thread on the right end of the left piston rod and clamp the piston head. The piston head has an inner semi-circular surface machined at its center, which mates with the quarter-circular arc surface at the right end of the left piston rod and the quarter-circular arc surface at the left end of the right piston rod. The inner surface of the damper cylinder and the outer circular channel of the piston head form a damping gap; The excitation coil is evenly wound around the piston head; Lead wire holes are machined on the left side of the piston head and the left piston rod, through which the lead wires of the excitation coil are led out.

2. The magnetorheological damper with a semi-circular annular winding frame according to claim 1, characterized in that, The piston head, left piston rod, right piston rod, and damper cylinder together form a semi-circular magnetic circuit; the piston head is a hollow structure with a semi-circular wound wire.

3. The magnetorheological damper with a semi-circular annular winding frame according to claim 1, characterized in that, A protective boss is machined on the left piston rod.

Images