A magnetorheological sealing device and its hub motor

Abstract

This invention relates to a magnetorheological sealing device and its hub motor, comprising a sealing ring, the sealing ring including 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 and second sealing lips and is filled with magnetorheological fluid. An excitation coil and a permanent magnet are disposed inside the sealing ring. The excitation coil is connected to an external power source to generate a magnetic field in the permanent magnet, and the magnetorheological fluid forms a sealing ring structure under the action of the magnetic field. The connection points between the first and second sealing lips and the support body are each provided with an inwardly inclined slope section. The sealing method of the magnetorheological fluid in this invention is not significantly affected by changes in operating conditions such as temperature, pressure, and vibration, exhibits stable performance, effectively copes with complex operating conditions, ensures long-term stable sealing effect, significantly extends the service life of the motor, and reduces maintenance costs.

Description

Technical Field

[0001] This invention relates to a magnetorheological sealing device and its hub motor, belonging to the field of hub motor technology. Background Technology

[0002] With the booming development of the electric vehicle industry, in-wheel motor technology has received increasing attention. In-wheel motors integrate power directly into the wheel, eliminating traditional components such as gearboxes and drive shafts, thus giving vehicles higher space utilization, more flexible powertrain layouts, and better handling performance. However, the unique working environment of in-wheel motors also presents significant sealing challenges.

[0003] Traditional wheel hub motors primarily rely on mechanical seals, such as rubber seals and oil seals. These seals can maintain a certain level of sealing effectiveness under static or low-speed conditions. However, wheel hub motors operate in the complex dynamic environment of vehicle movement. The centrifugal force generated by the high-speed rotation of the wheels, frequent vibrations, and impacts from harsh road conditions cause the mechanical seals to wear and deform rapidly. Water, dust, and mud from the road surface can easily penetrate the motor when the seals deteriorate. Moisture can cause short circuits in the motor windings and corrode metal components; excessive dust accumulation hinders heat dissipation, reduces motor efficiency, significantly shortens motor lifespan, and increases maintenance costs and the risk of vehicle malfunctions.

[0004] Meanwhile, traditional sealing methods struggle to adapt to varying operating conditions. The sealing requirements of hub motors are not constant under different weather conditions, driving speeds, and loads. For example, when a vehicle is driving through water, a high-strength seal is needed to block large amounts of water; however, when driving smoothly on dry, clean roads, an overly strong seal may increase unnecessary frictional losses and reduce energy efficiency. Traditional mechanical seals lack the ability to flexibly adjust sealing performance and cannot switch sealing states as needed. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a magnetorheological sealing device with stable sealing performance and its hub motor.

[0006] To achieve the objective, the technical solution adopted by this invention is:

[0007] A hub motor includes a magnetorheological sealing device. The 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 and is filled with magnetorheological fluid. An excitation coil and a permanent magnet are disposed inside the sealing ring. The excitation coil is connected to an external power source to generate a magnetic field in the permanent magnet. Under the action of the magnetic field, the magnetorheological fluid forms a sealing ring structure.

[0008] As a further optimization of the above technical solution, it also includes a rotor, a stator, a rim, and a central control microprocessor. The stator is located on the inner circumferential surface of the rim, and the rotor is located on the inner circumferential surface of the stator. The sealing ring seals the space between 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 sets of environmental sensing devices are installed on the side of the rim, and these multiple sets of environmental sensing devices are evenly distributed on the outer circumferential surface of the rim. The motor body supplies power to the environmental sensing devices. The environmental sensing devices are connected to the central control microprocessor. Each set of environmental sensing devices includes a temperature sensor, a humidity sensor, and a dust sensor.

[0009] 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, causing the magnetorheological fluid in the filling chamber to change to a high viscosity state.

[0010] As a further optimization of the above technical solution: the side of the rotor is provided with an installation step connected by a connecting plate, the sealing ring is sleeved on the installation 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 installation 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 cavity 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.

[0011] As a further optimization of the above technical solution: the connection between the first sealing lip, the second sealing lip and the support body is provided with an inwardly inclined slope section.

[0012] 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 opening of the filling chamber is greater than the radial width of the bottom of the filling chamber groove.

[0013] As a further optimization of the above technical solution: a metal skeleton is provided on the side of the sealing ring.

[0014] As a further optimization of the above technical solution: the filling chamber and the first sealing lip and the second sealing lip are all connected by connecting sections.

[0015] As a further optimization of the above technical solution, it also includes a rotating shaft and several screws. A bushing is movably sleeved on the rotating shaft. The bushing can rotate relative to the rotating shaft. The end of the mounting step is bent downward to form a fixing plate. The screws pass through the rim and the fixing plate in sequence and are fixed on the bushing. The stator and the rotating shaft are fixed together.

[0016] Compared with existing technologies, the magnetorheological sealing device of this invention has strong adaptive sealing capabilities. Through the detection of environmental sensors and the analysis of environmental data by the central control microprocessor, the viscosity of the magnetorheological fluid is precisely controlled, enabling automatic adjustment of the sealing state according to the actual working environment of the motor body. When the environmental sensors detect that the motor body is in a good environment (free from water, dust, etc.), the magnetorheological fluid in the filling chamber maintains a low viscosity state, which can achieve effective sealing and reduce resistance to motor rotation, thereby reducing energy consumption. When the environmental sensors detect 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 water, mud, dust and other impurities from entering the motor. The sealing method of the magnetorheological fluid is not significantly affected by changes in operating conditions such as temperature, pressure, and vibration, and its performance is stable. It can effectively cope with complex operating conditions, ensure long-term stable sealing effect, significantly extend the service life of the motor, and reduce maintenance costs. The inclined section prevents the sealing ring from falling off under the condition of high-speed rotation of the hub motor, and the inward inclination of the inclined section can also resist dust and impurities from the external environment. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the sealing ring in this invention.

[0018] Figure 2 This is a three-dimensional structural diagram of the sealing ring from another angle in this invention.

[0019] Figure 3 This is a schematic cross-sectional view of the sealing ring in this invention.

[0020] Figure 4 yes Figure 3 A magnified structural diagram of point A in the middle.

[0021] Figure 5 This is a cross-sectional structural diagram of the hub motor in this invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. For example... 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, and the filling chamber 15 is connected to the first sealing lip 12 and the second sealing lip 14 through connecting sections 13. The filling chamber 15 is filled with magnetorheological fluid. The sealing ring 1 contains 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.

[0023] 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 slope section 16. The slope section 16 causes the first sealing lip 12 and the second sealing lip 14 to be compressed and elastically deformed during sealing. This elastic deformation generates a radial clamping force pointing towards the sealing surface, ensuring that the first sealing lip 12 and the second sealing lip 14 are always firmly and tightly attached to the sealing surface, reducing the tendency to loosen due to vibration and impact. At the same time, the inwardly inclined slope section 16 is a reverse slope for impurities outside the motor. Impurities must pass through the slope section 16 to pass through the sealing gap. The slope section 16 significantly increases the path length and resistance of the impurities. The tight fit between the first sealing lip 12, the second sealing lip 14 and the sealing surface further reduces the sealing gap, making it more difficult for impurities to squeeze in.

[0024] 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 filling chamber 15. The cross-section of the filling chamber 15 is approximately trapezoidal. Compared with V-shaped and U-shaped filling chambers, the filling chamber 15 in this invention can accommodate more magnetorheological fluid, thereby enhancing the sealing performance.

[0025] In the above technical solution: the sealing ring 1 is made of fiber-reinforced rubber composite material. By adding fiber reinforcing materials (such as carbon fiber, glass fiber, etc.) to the rubber matrix, the strength, stiffness, and wear resistance of the sealing ring can be significantly improved, while maintaining the flexibility and sealing performance of the rubber. The addition of fibers can enhance the material's ability to confine the magnetorheological fluid, preventing excessive flow and leakage, and can also improve the durability of the sealing ring under complex stress environments.

[0026] In the above technical solution: a metal frame 17 is provided on the side of the sealing ring 1 to improve the assembly strength of the sealing ring body 1. The metal frame 17 plays a supporting role, ensuring that the sealing ring 1 can always be in the correct position during the high-speed rotation of the rotor, preventing it from falling off or flipping over, and enhancing the reliability of the seal.

[0027] The above 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 circumferential surface of the rim 7. The rotor 2 is located on the inner circumferential surface of the stator 3. There is a gap 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 hazard to the motor's operation and installation. The sealing ring 1 seals the space between the rotor 2 and the stator 3, and the magnetorheological fluid in the filling chamber 15 is in contact with the stator 3. The excitation coil 4 is connected to an intelligent power supply device 6 connected to the motor body. The intelligent power supply device 6 supplies power to the excitation coil 4. All the key hardware components (precision adjustable current source, sensor, processor, communication interface) and basic technology platform required for the intelligent power supply device 6 are mature and commercially available, and can be implemented through customized development and system integration. The specific structure and working principle of the intelligent power supply device 6 will not be elaborated here. Multiple sets of environmental sensors 8 are installed on the side of the wheel rim 7, evenly distributed on the outer circumference of the rim 7. The motor body supplies power to the environmental sensors 8. Each set of environmental sensors 8 includes a temperature sensor, a humidity sensor, and a dust sensor. Specifically, there are three sets of environmental sensors 8, arranged at a 120° angle to each other. The environmental sensors 8 are connected to the central control microprocessor via wireless or wired data transmission.

[0028] The environmental sensing device 8 detects the temperature, humidity, and dust in 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 the corresponding voltage signal. The intelligent power supply device 6 precisely controls the current in the excitation coil 4 of the sealing ring 1 and adjusts the magnetic field strength generated by the permanent magnet 5, thereby controlling the dynamic viscosity of the magnetorheological fluid in the filling chamber 15. This allows the magnetorheological fluid to 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 performance in harsh environments such as water or dust. When the environmental sensor 8 detects that the motor body is in a good environment (free from water, dust, etc.), the permanent magnet 5 inside the sealing ring 1 provides a basic magnetic field strength, keeping the magnetorheological fluid in the filling chamber 15 in a low-viscosity state. This achieves effective sealing, reduces resistance to motor rotation, and lowers energy consumption. When the environmental sensor 8 detects that the motor body is in a harsh environment, the motor body applies current to the excitation coil 4 through the intelligent power supply device 6. The current magnitude is adjusted according to the environmental conditions, thereby changing the magnetic field strength. This causes the magnetorheological fluid in the filling chamber 15 to become a high-viscosity state, tightly filling the sealing gap and effectively preventing water, mud, dust, and other impurities from entering the motor. Multiple evenly distributed environmental sensors 8 can more accurately measure various environmental data, ensuring that the environmental sensors 8 can monitor the environmental quality in real time during the operation of the motor body.

[0029] Compared to traditional sealing methods, magnetorheological (MR) seals are not significantly affected by changes in operating conditions such as temperature, pressure, and vibration. In high-temperature environments, the performance of the magnetorheological fluid remains relatively stable, unlike rubber seals which soften or age at high temperatures and lose their sealing ability. In low-temperature environments, it does not become brittle or crack, effectively handling complex operating conditions and demonstrating excellent stability. Facing the vibrations and centrifugal forces generated by the high-speed rotation of the motor, the magnetorheological fluid can maintain its sealed position without displacement or loosening, ensuring a long-term stable sealing effect, significantly extending the motor's service life, and reducing maintenance costs.

[0030] In the above technical solution: the rotor 2 has an installation step 21 connected to it via a connecting plate 22 on its side, and the sealing ring 1 is fitted onto the installation step 21. The stator 3 has a stator side plate 31 on its side, the end of which is bent and fitted onto the installation step 21. The side of the end of the stator side plate 31 has 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 side plate protrusion 32 makes the seal between the stator 3 and the rotor 2 tighter, enhancing the sealing effect; at the same time, the stator side plate 31 isolates the stator 3 and rotor 2 from the outside, thereby achieving a dustproof and waterproof sealing effect.

[0031] The above technical solution also includes a rotating shaft 9 and several screws 24. A bushing 10 is movably sleeved on the rotating shaft 9, and the bushing 10 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 on the bushing 10. The stator 3 and the rotating shaft 9 are fixed together.

[0032] The magnetorheological sealing device of this invention has strong adaptive sealing capability. Through the detection of the environmental sensing device 8 and the analysis of environmental data by the central control microprocessor, the viscosity of the magnetorheological fluid is precisely controlled, realizing automatic adjustment of the sealing state according to the actual working environment of the motor body. When the environmental sensing device 8 detects that the motor body is in a good environment (free from water, dust, etc.), the magnetorheological fluid in the filling chamber 15 maintains a low viscosity state, which can achieve effective sealing and reduce resistance to motor rotation, thereby reducing 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 water, mud, dust and other impurities from entering the motor. The sealing method of the magnetorheological fluid is not significantly affected by changes in operating conditions such as temperature, pressure, vibration, etc., and its performance is stable. It can effectively cope with complex operating conditions, ensure long-term stable sealing effect, significantly extend the service life of the motor, and reduce maintenance costs. The inclined section 16 prevents the sealing ring 1 from falling off under the condition of high-speed rotation of the hub motor. The inward inclination of the inclined section 16 can also resist dust, impurities and other external environmental factors.

[0033] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should fall within the protection scope of the present invention.

Claims

1. A hub motor, characterized in that... The device 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 filled with magnetorheological fluid. The sealing ring (1) is 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). The magnetorheological fluid forms a sealing ring structure under the action of the magnetic field. It also includes a rotor (2), a stator (3), a rim (7), and a central control microprocessor. The stator (3) is located on the inner circumferential surface of the rim (7), and the rotor (2) is located on the inner circumferential surface 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. The intelligent power supply device (6) supplies power to the excitation coil (4). Multiple sets of environmental sensing devices (8) are installed on the side of the rim (7). The multiple sets of environmental sensing devices (8) are evenly distributed on the outer circumferential surface of the rim (7). The motor body supplies power to the environmental sensing devices (8). The environmental sensing devices (8) are connected to the central control microprocessor. Each set 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) changes to a high viscosity state. The rotor (2) has an installation step (21) connected to the side by a connecting plate (22). The sealing ring (1) is fitted on the installation step (21). The stator (3) has a stator side plate (31) on its side. The end of the stator side plate (31) is bent and fitted on the installation step (21). The side of the end of the stator side plate (31) has a side plate protrusion (32). The side plate protrusion (32) 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).

2. A hub motor according to claim 1, characterized in that... The connection between the first sealing lip (12), the second sealing lip (14) and the support body (11) is provided with an inwardly inclined slope section (16).

3. A hub motor according to claim 1, characterized in that... 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 filling chamber (15).

4. A hub motor according to claim 1, characterized in that... The sealing ring (1) has a metal frame (17) on its side.

5. A hub motor 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 by a connecting section (13).

6. A hub motor according to claim 1, characterized in that... It also includes a rotating shaft (9) and several screws (24). A bushing (10) is movably fitted on the rotating shaft (9). The bushing (10) 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 on the bushing (10). The stator (3) and the rotating shaft (9) are fixed together.

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