Magnetorheological sealing device and hub motor thereof

Abstract

The magnetorheological sealing device comprises a sealing ring, the sealing ring comprises an annular supporting body, a first sealing lip, a second sealing lip and a filling cavity, the first sealing lip, the second sealing lip and the filling cavity are integrally formed on the supporting body, and the filling cavity is located between the first sealing lip and the second sealing lip. The filling cavity is filled with magnetorheological fluid, a magnet exciting coil and a permanent magnet are arranged in the sealing ring, the magnet exciting coil is externally connected with a power source to enable the permanent magnet to generate a magnetic field, and the magnetorheological fluid forms a sealing ring structure under the action of the magnetic field. Inclined plane sections inclining inwards are arranged at the connecting positions of the first sealing lip and the supporting body and the connecting positions of the second sealing lip and the supporting body. The sealing mode of the magnetorheological fluid is not obviously influenced by changes of working conditions such as temperature, pressure and vibration, the performance is stable, complex working conditions are effectively dealt with, the long-term stable sealing effect is guaranteed, the service life of the motor is obviously prolonged, and the maintenance cost is reduced.

Description

Technical Field

[0001] The invention relates to a magnetorheological sealing device and a hub motor thereof, belonging to the technical field of hub motors. Background Art

[0002] With the booming electric vehicle industry, in-wheel motor technology is gaining increasing attention. In-wheel motors integrate power directly into the wheel, eliminating traditional components like transmissions and drive shafts. This allows for greater vehicle space utilization, more flexible powertrain layout, and improved handling. However, the unique operating environment of in-wheel motors also presents significant sealing challenges.

[0003] Traditional in-wheel motor sealing methods rely primarily on mechanical seals, such as rubber seals and oil seals. These seals can maintain a certain sealing effect under static or low-speed operating conditions. However, in-wheel motors are subject to the complex dynamic environment of vehicle operation. The centrifugal force generated by the high-speed rotation of the wheels, frequent vibrations, and the impact of harsh road conditions can cause rapid wear and deformation of the mechanical seals. Water, dust, sediment, and other impurities on the road surface can easily take advantage of the seal's deterioration to penetrate the motor interior. Once moisture enters, it can cause short circuits in the motor windings and corrode metal components. Excessive dust accumulation can hinder heat dissipation in the motor, reducing efficiency, significantly shortening its lifespan, and increasing repair costs and the risk of vehicle failure.

[0004] At the same time, traditional sealing methods struggle to adapt to changing operating conditions. The sealing requirements for in-wheel motors vary depending on weather conditions, driving speeds, and loads. For example, when wading through water, a high-strength seal is crucial to prevent the flow of water. However, when driving smoothly on dry, clean roads, an overly strong seal can increase unnecessary friction and reduce energy efficiency. Traditional mechanical seals lack the ability to flexibly adjust sealing performance and cannot switch sealing states on demand. Summary of the Invention

[0005] The purpose of the present invention is to provide a magnetorheological sealing device with stable sealing performance and a hub motor thereof in view of the shortcomings of the prior art.

[0006] To achieve the purpose, the present invention adopts the following technical solutions: A magnetorheological sealing device includes a sealing ring, which includes an annular support body and a first sealing lip, a second sealing lip and a filling chamber integrally formed on the support body. The filling chamber is located between the first sealing lip and the second sealing lip. The filling chamber is filled with magnetorheological fluid. An excitation coil and a permanent magnet are provided inside the sealing ring. The excitation coil is connected to an external power supply to cause the permanent magnet to generate a magnetic field. The magnetorheological fluid forms a sealing ring structure under the action of the magnetic field.

[0007] As a further optimization of the above technical solution: the connections between the first sealing lip, the second sealing lip and the supporting body are all provided with inwardly inclined slope sections.

[0008] As a further optimization of the above technical solution: the inner circumferential surface of the filling chamber is inclined so that the radial width of the filling chamber opening is larger than the radial width of the filling chamber groove bottom.

[0009] As a further optimization of the above technical solution: a metal frame is provided on the side of the sealing ring.

[0010] As a further optimization of the above technical solution: the filling chamber and the first sealing lip and the second sealing lip are connected via a connecting section.

[0011] A hub motor includes a magnetorheological sealing device according to the above technical solution, and also includes a rotor, a stator, a rim and a central control microprocessor. The stator is located on the inner circumference of the rim, the rotor is located on the inner circumference of the stator, the sealing ring seals the rotor and the stator, the magnetorheological fluid in the filling chamber is in contact with the stator, the tail of the excitation coil is connected to an intelligent power supply device connected to the motor body, the intelligent power supply device supplies power to the excitation coil, multiple groups of environmental sensing devices are installed on the side of the rim, and the multiple groups of environmental sensing devices are evenly distributed on the outer circumference of the rim, the motor body supplies power to the environmental sensing devices, and the environmental sensing devices are connected to the central control microprocessor. Each group of environmental sensing devices includes a temperature sensor, a humidity sensor, and a dust sensor.

[0012] As a further optimization of the above technical solution: when the environmental sensing device detects that the motor body is in a good environment, the magnetorheological fluid in the filling chamber maintains a low viscosity state; when the environmental sensing device detects that the motor body is in a harsh environment, the motor body applies current to the excitation coil through the intelligent power supply device, so that the magnetorheological fluid in the filling chamber is converted into a high viscosity state.

[0013] As a further optimization of the above technical solution: the side of the rotor is provided with a mounting step connected by a connecting plate, the sealing ring is sleeved on the mounting step, the side of the stator is provided with a stator side plate, the end of the stator side plate is bent and sleeved on the mounting step, the side of the end of the stator side plate is provided with a side plate protrusion, the side plate protrusion is inserted into the filling chamber of the sealing ring, and the first sealing lip and the second sealing lip are both in close contact with the side of the stator side plate.

[0014] As a further optimization of the above technical solution: it also includes a rotating shaft and several screws, the movable sleeve on the rotating shaft is provided with a shaft sleeve, the shaft sleeve can rotate relative to the rotating shaft, the end of the mounting step is bent downward to form a fixed plate, the screws pass through the rim and the fixed plate in sequence and are fixed on the shaft sleeve, and the stator and the rotating shaft are fixed.

[0015] Compared with the prior art, the magnetorheological sealing device of the present invention has strong adaptive sealing capabilities. Through detection by an environmental sensing device and analysis of environmental data by a central control microprocessor, the viscosity of the magnetorheological fluid is precisely controlled, achieving automatic adjustment of the sealing state according to the actual operating environment of the motor body. When the environmental sensing device detects that the motor body is in a good environment (free of water, dust, etc.), the magnetorheological fluid in the filling chamber maintains a low viscosity state, which not only achieves effective sealing but also reduces resistance to motor rotation and reduces energy consumption. When the environmental sensing device detects that the motor body is in a harsh environment, the magnetorheological fluid in the filling chamber changes to a high viscosity state, tightly filling the sealing gap, thereby effectively preventing impurities such as water, sand, and dust from entering the motor interior. The magnetorheological fluid's sealing method is not significantly affected by changes in operating conditions such as temperature, pressure, and vibration. The performance is stable, effectively copes with complex operating conditions, ensures long-term stable sealing, significantly extends the service life of the motor, and reduces maintenance costs. The inclined section prevents the sealing ring from falling off under high-speed rotation conditions of the hub motor. The inward inclination of the inclined section also protects against dust and impurities in the external environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the sealing ring in the present invention.

[0017] Figure 2 It is a schematic diagram of the three-dimensional structure of the sealing ring in the present invention from another angle.

[0018] Figure 3 It is a schematic diagram of the cross-sectional structure of the sealing ring in the present invention.

[0019] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure at point A in the middle.

[0020] Figure 5 It is a schematic cross-sectional structure diagram of the hub motor in the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Figure 1-5As shown, the hub motor includes a magnetorheological sealing device, which includes a sealing ring 1. The sealing ring 1 includes an annular support body 11 and a first sealing lip 12, a second sealing lip 14, and a filling chamber 15 integrally formed on the support body 11. The filling chamber 15 is located between the first sealing lip 12 and the second sealing lip 14. The filling chamber 15 is connected to the first sealing lip 12 and the second sealing lip 14 by a connecting section 13. The filling chamber 15 is filled with magnetorheological fluid. The sealing ring 1 is internally provided with an excitation coil 4 and a permanent magnet 5. The excitation coil 4 is connected to an external power source to generate a magnetic field in the permanent magnet 5. Under the action of the magnetic field, the magnetorheological fluid forms a sealing ring structure.

[0022] In the above technical solution, the connection between the first sealing lip 12, the second sealing lip 14, and the support body 11 is provided with an inwardly inclined bevel section 16. Bevel section 16 causes the first and second sealing lips 12, 14 to be squeezed and elastically deformed during sealing. This elastic deformation generates a radial clamping force directed toward the sealing surface, ensuring that the first and second sealing lips 12, 14 always adhere firmly to the sealing surface, reducing the tendency to loosen due to vibration and impact. Furthermore, the inwardly inclined bevel section 16 acts as a counter-bevel for impurities outside the motor. Impurities must pass through bevel section 16 to pass through the sealing gap, significantly increasing the path length and resistance of the impurities. The close fit between the first and second sealing lips 12, 14 and the sealing surface further reduces the sealing gap, making it more difficult for impurities to enter.

[0023] In the above technical solution: the inner circumferential surface of the filling chamber 15 is inclined so that the radial width of the opening of the filling chamber 15 is greater than the radial width of the bottom of the groove of the filling chamber 15. The cross-section of the filling chamber 15 is approximately trapezoidal. Compared with the V-type and U-type, the filling chamber 15 in the present invention can accommodate more magnetorheological fluid, thereby enhancing the sealing performance.

[0024] In the above technical solution, sealing ring 1 utilizes a fiber-reinforced rubber composite material. By adding fiber reinforcement (such as carbon fiber or glass fiber) to the rubber matrix, the sealing ring's strength, rigidity, and wear resistance are significantly improved while maintaining the rubber's flexibility and sealing properties. The addition of fiber enhances the material's ability to constrain the magnetorheological fluid, preventing excessive flow and leakage, and improves the sealing ring's durability in complex stress environments.

[0025] In the above technical solution, a metal frame 17 is provided on the side of the sealing ring 1 to enhance the assembly strength of the sealing ring body 1. The metal frame 17 provides support, ensuring that the sealing ring 1 remains in the correct position during high-speed rotation of the rotor, preventing it from falling off or flipping, and thus enhancing sealing reliability.

[0026] The above-described technical solution also includes a rotor 2, a stator 3, a rim 7, and a central control microprocessor. The stator 3 is located on the inner circumference of the rim 7. The rotor 2 is located on the inner circumference of the stator 3. A gap exists between the rotor 2 and the stator 3. External impurities such as dust and moisture can easily enter the motor through this gap during operation, posing a significant risk to the motor's operation and installation. A sealing ring 1 seals the rotor 2 and stator 3, and the magnetorheological fluid in the filling chamber 15 contacts the stator 3. The excitation coil 4 is connected to an intelligent power supply device 6 connected to the motor body. This intelligent power supply device 6 supplies power to the excitation coil 4. All key hardware components (precision adjustable current source, sensors, processor, communication interface) and the underlying technology platform required for this intelligent power supply device 6 are highly mature and commercially available, allowing for customized development and system integration. The specific structure and operating principle of the intelligent power supply device 6 will not be detailed here. Multiple sets of environmental sensing devices 8 are mounted on the side of the rim 7, evenly distributed across its outer circumference. Power is supplied by the motor. Each set includes a temperature sensor, a humidity sensor, and a dust sensor. Specifically, there are three sets of environmental sensing devices 8, arranged at a 120° angle. These are connected to the central control microprocessor via wireless or wired data transmission.

[0027] The environmental sensing device 8 detects the temperature, humidity, and dust of the environment, transmits the data back to the central control microprocessor in real time, processes and analyzes the environmental data in a timely manner, and outputs a corresponding voltage signal. The intelligent power supply device 6 is used to accurately control the current in the excitation coil 4 of the sealing ring 1, adjust the magnetic field strength generated by the permanent magnet 5, and thus control the dynamic viscosity of the magnetorheological fluid in the filling chamber 15, so that the magnetorheological fluid can automatically adjust the sealing state according to the actual working environment of the motor, ensuring that the magnetorheological fluid and the sealing ring 1 maintain strong sealing properties in harsh environments such as water or dust. When the environmental sensing device 8 detects that the motor body is in a favorable environment (free of water, dust, etc.), the permanent magnet 5 within the sealing ring 1 provides a basic magnetic field strength, maintaining a low viscosity for the magnetorheological fluid in the filling chamber 15. This effectively seals the motor while reducing resistance to motor rotation and lowering energy consumption. When the environmental sensing device 8 detects that the motor body is in a harsh environment, the motor body applies a current to the excitation coil 4 via the intelligent power supply device 6, adjusting the current according to the environmental conditions. This changes the magnetic field strength, causing the magnetorheological fluid in the filling chamber 15 to transition to a high viscosity state, tightly filling the sealing gap and effectively preventing impurities such as water, sand, and dust from entering the motor interior. Multiple evenly distributed sets of environmental sensing devices 8 enable more accurate measurement of various environmental data, ensuring that the environmental sensing devices 8 can monitor environmental quality in real time during motor operation.

[0028] Compared to traditional sealing methods, magnetorheological seals are not significantly affected by operating conditions such as temperature, pressure, and vibration. In high-temperature environments, magnetorheological fluid (MRF) maintains relatively stable performance, unlike rubber seals that soften and age at high temperatures and lose their sealing ability. In low-temperature environments, it also resists becoming brittle or cracking, effectively handling complex operating conditions and demonstrating excellent stability. Despite the vibration and centrifugal forces generated by high-speed motor rotation, MRF maintains its sealing position without shifting or loosening, ensuring long-term, stable sealing, significantly extending the motor's lifespan and reducing maintenance costs.

[0029] In the above technical solution, the side of the rotor 2 is provided with a mounting step 21 connected via a connecting plate 22, and the sealing ring 1 is mounted on the mounting step 21. The side of the stator 3 is provided with a stator side plate 31, the end of which is bent and mounted on the mounting step 21. The side of the end of the stator side plate 31 is provided with a side plate protrusion 32, which is inserted into the filling chamber 15 of the sealing ring 1. The first sealing lip 12 and the second sealing lip 14 are both in close contact with the side of the stator side plate 31. The provision of the side plate protrusion 32 ensures a tighter seal between the stator 3 and the rotor 2, enhancing the sealing effect. At the same time, the stator side plate 31 isolates the stator 3 and the rotor 2 from the outside, thereby achieving a dustproof and waterproof sealing effect.

[0030] The above technical solution also includes a rotating shaft 9 and several screws 24. A sleeve 10 is movably mounted on the rotating shaft 9 and can rotate relative to the rotating shaft 9. The end of the mounting step 21 is bent downward to form a fixing plate 23. The screws 24 pass through the rim 7 and the fixing plate 23 in sequence and are fixed to the sleeve 10, thereby fixing the stator 3 and the rotating shaft 9.

[0031] The magnetorheological sealing device of the present invention has a strong adaptive sealing capability. Through detection by the environmental sensing device 8 and analysis of environmental data by the central control microprocessor, the viscosity of the magnetorheological fluid is precisely controlled, achieving automatic adjustment of the sealing state according to the actual operating environment of the motor body. When the environmental sensing device 8 detects that the motor body is in a good environment (free of water, dust, etc.), the magnetorheological fluid in the filling chamber 15 maintains a low viscosity state, which not only achieves effective sealing but also reduces resistance to motor rotation and reduces energy consumption. When the environmental sensing device 8 detects that the motor body is in a harsh environment, the magnetorheological fluid in the filling chamber 15 changes to a high viscosity state, tightly filling the sealing gap, thereby effectively preventing impurities such as water, sand, and dust from entering the motor interior. The magnetorheological fluid's sealing method is not significantly affected by changes in operating conditions such as temperature, pressure, and vibration. The performance is stable, effectively coping with complex operating conditions, ensuring long-term and stable sealing, significantly extending the service life of the motor, and reducing maintenance costs. The inclined surface section 16 prevents the sealing ring 1 from falling off under high-speed rotation conditions of the hub motor. The inward inclination of the inclined surface section 16 also protects against dust and impurities in the external environment.

[0032] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should fall within the scope of protection of the present invention.

Claims

1. A magnetorheological sealing device, characterized in that The invention comprises a sealing ring (1), wherein the sealing ring (1) comprises an annular supporting body (11) and a first sealing lip (12), a second sealing lip (14) and a filling chamber (15) integrally formed on the supporting body (11); the filling chamber (15) is located between the first sealing lip (12) and the second sealing lip (14); the filling chamber (15) is filled with magnetorheological fluid; an excitation coil (4) and a permanent magnet (5) are provided inside the sealing ring (1); the excitation coil (4) is connected to an external power supply to enable the permanent magnet (5) to generate a magnetic field; and the magnetorheological fluid forms a sealing ring structure under the action of the magnetic field.

2. A magnetorheological sealing device according to claim 1, characterized in that The connections between the first sealing lip (12), the second sealing lip (14) and the supporting body (11) are each provided with an inwardly inclined slope section (16).

3. A magnetorheological sealing device according to claim 1, characterized in that The inner circumferential surface of the filling chamber (15) is arranged to be inclined, so that the radial width of the opening of the filling chamber (15) is greater than the radial width of the groove bottom of the filling chamber (15).

4. A magnetorheological sealing device according to claim 1, characterized in that A metal frame (17) is provided on the side of the sealing ring (1).

5. The magnetorheological sealing device according to claim 1, characterized in that The filling chamber (15) and the first sealing lip (12) and the second sealing lip (14) are all connected via a connecting section (13).

6. A hub motor comprising a magnetorheological sealing device according to any one of claims 1 to 5, characterized in that The invention also includes a rotor (2), a stator (3), a rim (7) and a central control microprocessor, wherein the stator (3) is located on the inner circumference of the rim (7), the rotor (2) is located on the inner circumference of the stator (3), the sealing ring (1) seals the rotor (2) and the stator (3), the magnetorheological fluid in the filling chamber (15) is in contact with the stator (3), the tail of the excitation coil (4) is connected to an intelligent power supply device (6) connected to the motor body, and the intelligent power supply device (6) supplies power to the excitation coil (4), and multiple groups of environmental sensing devices (8) are installed on the side of the rim (7), and the multiple groups of environmental sensing devices (8) are evenly distributed on the outer circumference of the rim (7). The motor body supplies power to the environmental sensing devices (8), and the environmental sensing devices (8) are connected to the central control microprocessor. Each group of environmental sensing devices (8) includes a temperature sensor, a humidity sensor, and a dust sensor. When the environmental sensing device (8) detects that the motor body is in a good environment, the magnetorheological fluid in the filling chamber (15) maintains a low viscosity state; when the environmental sensing device (8) detects that the motor body is in a bad environment, the motor body applies current to the excitation coil (4) through the intelligent power supply device (6), so that the magnetorheological fluid in the filling chamber (15) is converted into a high viscosity state.

7. The hub motor according to claim 6, characterized in that The side surface of the rotor (2) is provided with a mounting step (21) connected via a connecting plate (22), the sealing ring (1) is sleeved on the mounting step (21), the side surface of the stator (3) is provided with a stator side plate (31), the end of the stator side plate (31) is bent and sleeved on the mounting step (21), the side surface of the end of the stator side plate (31) is provided with a side plate protrusion (32), the side plate protrusion (32) is inserted into the filling chamber (15) of the sealing ring (1), and the first sealing lip (12) and the second sealing lip (14) are both in close contact with the side surface of the stator side plate (31).

8. The hub motor according to claim 7, characterized in that It also includes a rotating shaft (9) and a plurality of screws (24). A sleeve (10) is provided on the movable sleeve of the rotating shaft (9). The sleeve (10) can rotate relative to the rotating shaft (9). The end of the mounting step (21) is bent downward to form a fixed plate (23). The screws (24) pass through the rim (7) and the fixed plate (23) in sequence and are fixed to the sleeve (10). The stator (3) and the rotating shaft (9) are fixed to each other.

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