Self-sensing magneto-rheological rotary damper

Abstract

The self-sensing magneto-rheological rotary damper of the application comprises a magneto-rheological damping part and an angular velocity self-sensing part, the rotating shaft of the rotary damper is divided into two parts of upper rotating shaft and lower rotating shaft, and the upper and lower rotating shafts are connected through threaded holes; the angular velocity self-sensing part comprises a friction nano power generation unit and a signal processing unit; the friction nano electric structure is installed on the lower rotating shaft, a polytetrafluoroethylene sleeve is fixed on the lower shell, an aluminum foil is pasted on a polypropylene cylinder, and the cylinder is fixed on the lower rotating shaft; the upper rotating shaft is connected with a motor; the rotating shaft is located in the shell, the magneto-rheological fluid is filled in the gap between the rotating disc and the shell, and a bearing is arranged on the upper part and the lower part of the shell respectively, so that the rotor can rotate independently of the shell; and the excitation coil is wound on an aluminum alloy framework and fixed in the shell. The self-sensing magneto-rheological rotary damper designed in the application is suitable for the damping force required by rotary motion; meanwhile, the structure of the system is simplified, and the stability of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of magnetorheological rotating damper technology, and specifically to a self-sensing magnetorheological rotating damper. Background Technology

[0002] Magnetorheological (MR) rotary dampers, as semi-active devices, feature continuously adjustable damping, short response time, and low energy consumption. They are widely used in vehicle braking, robot joints, and other applications. Typically, MR rotary dampers require external sensors to obtain system status information. With system development, the use of external sensors increases the complexity of the damper system. To reduce costs and improve system reliability, designing a MR rotary damper with self-sensing capabilities is a solution. Currently, MR dampers with self-sensing capabilities are mainly linear self-sensing MR dampers designed based on the principles of electromagnetic induction and triboelectric nanogenerators.

[0003] Current magnetorheological dampers with self-sensing capabilities mainly control vibrations generated by linear motion based on the principles of electromagnetic induction or triboelectric nanogeneration to achieve vibration reduction. Therefore, these self-sensing magnetorheological dampers are only suitable for linear motion and not for rotational motion. Therefore, this invention designs a self-sensing magnetorheological rotational damper specifically for rotational motion. Summary of the Invention

[0004] The present invention proposes a self-sensing magnetorheological rotary damper, which can solve the technical problem that magnetorheological rotary dampers require external sensors to obtain damper system information.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A self-sensing magnetorheological rotary damper includes a magnetorheological damping section and an angular velocity self-sensing section.

[0007] The rotating shaft of the rotary damper is divided into two parts: an upper rotating shaft and a lower rotating shaft, which are connected by a threaded hole.

[0008] The angular velocity self-sensing component includes a triboelectric nanogenerator unit and a signal processing unit;

[0009] A triboelectric nanostructure is installed on the lower rotating shaft, a polytetrafluoroethylene sleeve is fixed to the lower housing, an aluminum foil is attached to a polypropylene cylinder, and the cylinder is fixed to the lower rotating shaft; the upper rotating shaft is connected to the motor.

[0010] The rotating shaft is located inside the housing, and the magnetorheological fluid fills the gap between the turntable and the housing. A bearing is placed in the upper and lower parts of the housing, allowing the rotor to rotate independently of the housing.

[0011] When the shaft rotates, the aluminum foil fixed on the shaft rubs against the polytetrafluoroethylene, generating an electrical signal on the aluminum electrode. The signal processing unit then converts the electrical signal into a current signal related to the angular velocity.

[0012] It also includes an excitation coil wound around an aluminum alloy frame and fixed inside the housing.

[0013] Furthermore, a pair of U-shaped sealing rings are placed inside the upper and lower housings respectively to ensure the sealing of the magnetorheological fluid.

[0014] Furthermore, to ensure that the magnetic field forms a closed loop between the rotating shaft, the upper and lower shells, and the magnetorheological fluid, the upper and lower shells and the upper rotating shaft are made of high-permeability 45 steel.

[0015] Furthermore, the triboelectric nanogenerator unit includes a grating-shaped independent triboelectric layer and two sets of interdigitated metal electrodes with complementary shapes.

[0016] Furthermore, the aluminum foil consists of two sets of complementary interdigitated aluminum foils attached to the cylinder to form two sets of metal electrodes.

[0017] Furthermore, the arc length distance between adjacent aluminum electrodes is 2.5 mm, the width of each aluminum electrode is 5 mm, and the two sets of complementary interdigitated electrodes have a total of 16 electrode units.

[0018] Furthermore, the grating-like periodicity of the sleeve is consistent with the periodicity of the aluminum electrode.

[0019] As can be seen from the above technical solution, the self-sensing magnetorheological rotary damper of the present invention uses a single-disc magnetorheological rotary damper for the rotary damper part. Therefore, it can be designed to connect other types of magnetorheological rotary dampers with the self-sensing structure. For the self-sensing structure part, the present invention uses a structure designed based on the principle of triboelectric nanogenerator. Aluminum and PTFE are selected as the materials. Other materials, such as copper and polyimide films, are also feasible for triboelectric nanogenerator. Structurally, the present invention uses a cylindrical PTFE cylinder with a grating-shaped independent friction layer and two sets of interdigitated electrodes with complementary shapes. The interdigitated electrodes rotate with the rotation axis and generate friction with the independent PTFE friction layer. If the independent PTFE friction layer rotates with the rotation axis, the interdigitated electrodes remain fixed. Generating an electrical signal through friction between the two is also feasible.

[0020] Currently known dampers with self-sensing capabilities are all linear dampers. The key point of this invention lies in the combination of a self-sensing structure based on the principle of triboelectric nanogenerators and a magnetorheological rotary damper to achieve the angular velocity self-sensing function of the magnetorheological rotary damper.

[0021] Currently, magnetorheological dampers with self-sensing capabilities are linear self-sensing magnetorheological dampers. They are only suitable for linear motion and not for rotational motion. The self-sensing magnetorheological rotational damper designed in this invention is suitable for the damping force required for rotational motion. It also simplifies the system structure and improves system stability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention;

[0023] Figure 2 This is a structural assembly diagram of the triboelectric nanogenerator unit on the lower rotating shaft;

[0024] Figure 3 This is a schematic diagram of the self-sensing structure of the present invention;

[0025] 1-Upper shaft; 2-Bearing; 3-Upper housing; 4-Magnetorheological fluid; 5-Lower housing; 6-Bearing; 7-PTFE sleeve; 8-Lower pressure cap; 9-Aluminum electrode; 10-Polypropylene cylinder; 11-Lower shaft; 12-U-shaped sealing ring; 13-Excitation coil; 14-Aluminum alloy frame; 15-U-shaped sealing ring; 16-Upper pressure cap. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0027] Figure 1 This is a cross-sectional view of a self-sensing magnetorheological rotary damper, as shown below. Figure 1As shown, a self-sensing rotary magnetorheological damper composed of a magnetorheological damping section and an angular velocity self-sensing section is proposed. The rotation shaft of the rotary damper is divided into an upper rotating shaft 1 and a lower rotating shaft 11. The upper and lower rotating shafts are connected by a threaded hole to ensure consistent rotation. The angular velocity self-sensing section includes a triboelectric nanogenerator unit and a signal processing unit. To achieve angular velocity self-sensing of the rotator, a triboelectric nanostructure is installed on the lower rotating shaft. A polytetrafluoroethylene (PTFE) sleeve 7 is fixed to the lower housing 5, and an aluminum foil is attached to a polypropylene cylinder 10, which is fixed to the lower rotating shaft 11. The upper rotating shaft 1 is connected to a motor. When the shaft rotates, the aluminum foil fixed on the shaft rubs against the PTFE. At this time, an electrical signal is generated on the aluminum electrode. Then, the signal processing unit converts the electrical signal into a current signal related to the angular velocity. The relationship between the angular velocity and the current signal is analyzed, realizing a self-sensing rotary damper with angular velocity self-sensing. In the magnetorheological damping section, a single-disc magnetorheological damper is designed. The rotating shaft is located inside the housing, and magnetorheological fluid fills the gap between the turntable and the housing. Bearings are placed at the upper and lower parts of the housing, allowing the rotor to rotate independently of the housing. A pair of U-shaped sealing rings 15 are placed inside the upper housing 3 and lower housing 5, respectively, to ensure the sealing of the magnetorheological fluid. The excitation coil is wound on an aluminum alloy frame and fixed inside the housing. When a direct current is applied to the excitation coil 13, an induced magnetic field is generated within the rotary damper, braking the rotational motion. To ensure that the magnetic field forms a closed loop between the rotating shaft, upper and lower housings, and magnetorheological fluid, the upper and lower housings and the upper rotating shaft are made of high-permeability 45 steel, while the remaining structures are made of non-magnetic aluminum alloy or polytetrafluoroethylene (PTFE).

[0028] Figure 2 This is an assembly diagram of the triboelectric nanogenerator unit on the lower rotating shaft. It mainly consists of a grating-shaped independent friction layer and two sets of complementary interdigitated metal electrodes. Based on the triboelectric sequence, polytetrafluoroethylene (PTFE) is selected as the material for the independent friction layer. Aluminum is selected as the material for the metal electrodes. A polypropylene cylinder is fixed to the lower rotating shaft, and two sets of complementary interdigitated aluminum foil are attached to the cylinder to form the two sets of metal electrodes. The arc length distance between adjacent aluminum electrodes is 2.5 mm, and the width of each aluminum electrode is 5 mm. The two sets of complementary interdigitated electrodes contain a total of 16 electrode units. The grating-shaped periodicity of the PTFE sleeve matches the periodicity of the aluminum electrodes. When the rotating shaft rotates, it drives the aluminum electrodes to rotate, generating friction with the PTFE sleeve, thus producing an electrical signal related to the rotational speed.

[0029] Figure 3This is a schematic diagram of the self-sensing structure. The working principle of the magnetorheological rotating damper's self-sensing structure mainly involves the coupling of contact charge and in-plane sliding induced charge transfer. Initially, the grating row of PTFE completely overlaps with the grating of the metal electrode group. Because PTFE has a greater triboeity than aluminum when the two surfaces are in contact, a negative charge is generated on the PTFE surface, while an equal amount of positive charge is generated on the aluminum electrode group 2 (AE2). At this time, due to electrostatic equilibrium, there is no charge flow between the two electrodes, and therefore no current is generated.

[0030] As the aluminum electrode layer rotates counterclockwise, the PTFE triboelectric layer rotates relatively clockwise. The gate layer of the triboelectric layer gradually moves from position AE2 to position AE1, creating a potential drop that drives positive charges from AE2 to AE1, thus generating a transient current in the external load. Once the PTFE moves to a position completely overlapping with AE1, all positive charges are transferred to that electrode, achieving another electrostatic equilibrium. As the PTFE continues to move towards AE2 in another step, the positive charges are electrostatically attracted and flow back. A reverse current is generated in the circuit, completing one power generation cycle. When the aluminum electrode layer rotates clockwise, the reverse process occurs.

[0031] In this invention, a single-disc magnetorheological rotary damper is selected for the rotary damper section. Therefore, other types of magnetorheological rotary dampers can be designed to connect with the self-sensing structure. For the self-sensing structure section, this invention uses a structure designed based on the principle of triboelectric nanogenerators. Aluminum and PTFE are selected as the materials. Other materials, such as copper and polyimide films, are also feasible for triboelectric nanogenerators. Structurally, this invention uses a cylindrical PTFE cylinder with a grating-shaped independent friction layer and two sets of interdigitated electrodes with complementary shapes. The interdigitated electrodes rotate with the rotation axis and generate friction with the independent PTFE friction layer. If the independent PTFE friction layer rotates with the rotation axis, the interdigitated electrodes remain fixed. Generating an electrical signal through friction between the two is also feasible.

[0032] Currently known dampers with self-sensing capabilities are all linear dampers. The key point of this invention lies in the combination of a self-sensing structure based on the principle of triboelectric nanogenerators and a magnetorheological rotary damper to achieve the angular velocity self-sensing function of the magnetorheological rotary damper.

[0033] Currently, magnetorheological dampers with self-sensing capabilities are linear self-sensing magnetorheological dampers. They are only suitable for linear motion and not for rotational motion. The self-sensing magnetorheological rotational damper designed in this invention is suitable for the damping force required for rotational motion. It also simplifies the system structure and improves system stability.

[0034] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-sensing magnetorheological rotary damper, comprising a magnetorheological damping section and an angular velocity self-sensing section, characterized in that, The rotating shaft of the rotary damper is divided into two parts: an upper rotating shaft and a lower rotating shaft, which are connected by a threaded hole. The angular velocity self-sensing component includes a triboelectric nanogenerator and a signal processing unit; A triboelectric nanostructure is installed on the lower shaft, a polytetrafluoroethylene sleeve is fixed to the lower housing, aluminum foil is attached to a polypropylene cylinder, and the polypropylene cylinder is fixed to the lower shaft; the upper shaft is connected to the motor. The rotating shaft is located inside the housing, and the magnetorheological fluid fills the gap between the turntable and the housing. A bearing is placed in the upper and lower parts of the housing, allowing the rotor to rotate independently of the housing. When the shaft rotates, the aluminum foil fixed on the shaft rubs against the polytetrafluoroethylene, generating an electrical signal on the aluminum electrode. The signal processing unit then converts the electrical signal into a current signal related to the angular velocity. It also includes an excitation coil wound around an aluminum alloy frame and fixed inside the housing; It also includes a pair of U-shaped sealing rings placed in the upper and lower housings respectively to ensure the sealing of the magnetorheological fluid.

2. The self-sensing magnetorheological rotary damper according to claim 1, characterized in that: To ensure that the magnetic field forms a closed loop between the rotating shaft, the upper and lower shells, and the magnetorheological fluid, the upper and lower shells and the upper rotating shaft are made of high-permeability 45 steel.

3. The self-sensing magnetorheological rotary damper according to claim 1, characterized in that: The triboelectric nanogenerator unit includes a grating-shaped independent triboelectric layer and two sets of interdigitated metal electrodes with complementary shapes.

4. The self-sensing magnetorheological rotary damper according to claim 1, characterized in that: The aluminum foil consists of two sets of complementary interdigitated aluminum foils attached to a cylinder to form two sets of metal electrodes.

5. The self-sensing magnetorheological rotary damper according to claim 4, characterized in that: The arc length distance between adjacent aluminum electrodes is 2.5 mm, the width of each aluminum electrode is 5 mm, and the two sets of complementary interdigitated electrodes have a total of 16 electrode units.

6. The self-sensing magnetorheological rotary damper according to claim 3, characterized in that: The grating-like periodicity of the sleeve is consistent with the periodicity of the aluminum electrode.

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