A hub electric drive vehicle axle

Abstract

This invention discloses a hub-driven electric axle, belonging to the technical field of electric drive axles. It includes an axle body with hub assemblies containing built-in hub motors mounted at both ends. A housing is integrally cast in the middle of the axle body, and a flange cover is bolted to the top of the housing. Unsprung mass dispersion units are provided at both ends of the axle body. It also includes a heat exchange core assembly and a connector unit. The heat exchange core assembly is fixed inside the housing. The heat exchange core assembly includes a first-flow heat exchanger and a second-flow heat exchanger arranged vertically, with a heat insulation pad between them. Multiple frame beams are bolted to the exterior of the first and second flow heat exchangers. This hub-driven electric axle can adapt to the large unsprung mass conditions of hub-driven electric vehicles, efficiently dissipate heat from inside the hub, and improve the vehicle's lateral stability during cornering.

Description

Technical Field

[0001] This invention specifically relates to a hub-driven electric vehicle axle, belonging to the field of electric drive vehicle axle technology. Background Technology

[0002] Existing electric drive structures include central electric drive assemblies, integrated electric drive axles, and hub electric drive axles. Central electric drive assemblies replace the engine and transmission with an electric motor and reducer structure, suitable for light, medium, and heavy-duty vehicles. However, they suffer from long transmission routes and low driving efficiency. Integrated electric drive axles offer advantages such as short transmission routes, high integration, and light weight, solving the problems of difficult chassis layout and high energy consumption associated with central electric drive assemblies. However, they often employ rigid structures, making them unsuitable for all-wheel drive or high-pass-off-road vehicles. Hub electric drive axles integrate the motor and reducer within the wheel-side assembly. For example, Chinese Patent Publication No. CN119116678A discloses a hub electric drive axle comprising two sets of parking brake assemblies, steering knuckle assemblies, motor assemblies, service brake assemblies, and wheel-side reducer assemblies, symmetrically arranged on both sides of the electric drive axle. The drive assembly and wheel-side reducer assembly are axially connected sequentially. This axle structure has a compact layout and small axial space, facilitating vehicle arrangement. However, the axle structure corresponding to the wheel hub electric drive structure is not disclosed. Existing conventional axle structures are difficult to match the usage requirements of wheel hub electric drive, resulting in the following defects: The wheel hub motor is integrated into the wheel side, leading to a significant increase in unsprung mass. The bending load-bearing capacity of the conventional axle body is insufficient, and the static bending stress at both ends of the axle is too large under long-term service, making it prone to fatigue deformation. The wheel hub motor itself generates heat during operation, and since the service brake is located adjacent to the motor stator, a large amount of heat generated during braking will be directly transferred to the wheel hub motor windings. High temperatures can easily cause permanent magnet demagnetization and high-temperature volatilization of wheel hub bearing grease. At the same time, high temperatures will accelerate the aging of rubber seals at the wheel hub, causing seal failure and seriously affecting the service life and operational reliability of the wheel hub motor. When the vehicle turns at high speed, the wheel end bears a large lateral centrifugal force, and the steering knuckle of the conventional axle is prone to lateral deformation, affecting driving stability and steering accuracy. Summary of the Invention

[0003] To address the aforementioned issues, this invention proposes a hub electric drive axle that can adapt to the large unsprung mass conditions of hub electric drive, while efficiently dissipating heat from inside the hub and improving the vehicle's lateral stability during cornering.

[0004] The present invention relates to a hub-driven electric drive axle, comprising an axle body, hub assemblies with built-in hub motors mounted at both ends of the axle body, a housing integrally cast in the middle of the axle body, and a flange cover plate bolted to the top of the housing; and further comprising: A heat exchange core assembly is fixed inside the containment chamber. The heat exchange core assembly includes a first medium heat exchanger and a second medium heat exchanger arranged vertically. A heat insulation pad is provided between the first and second medium heat exchangers. Multiple frame beams are bolted to the exterior of the first and second medium heat exchangers, and the bottom of the frame beams is bolted to the bottom of the containment chamber. A first pump body and a second pump body are respectively fixed to the heat exchange output ends of the first and second medium heat exchangers. A first output tee and a second output tee are respectively connected to the output ends of the first and second pump bodies. The two ends of the first output tee are connected to... The axle is equipped with an air-cooled output pipeline, and the second output tee is connected to two ends of a medium output pipeline. The heat exchange input ends of the first and second medium heat exchangers are respectively connected to a first input tee and a second input tee. The first input tee is connected to two ends of an air-cooled input pipeline, and the second input tee is connected to two ends of a medium input pipeline. The first and second medium heat exchangers are respectively provided with an industrial medium input end and an industrial medium output end on opposite sides. The industrial medium input end is connected to the air conditioning system through a pump set. The air-cooled output pipeline, the medium output pipeline, the air-cooled input pipeline, and the medium input pipeline extend from the inside of the axle body to both ends. The connector unit includes a first sealing seat that is fitted and fixed at the center of the stator of the hub motor, and a waterproof connector is fixed at the center of the first sealing seat; four sets of pressure check valves are fixed on the side of the first sealing seat near the hub motor, two sets of pressure check valves are connected to the hub motor cooling pipeline; one end of the other two sets of pressure check valves is hollow, and the other end of the four sets of pressure check valves is fixed with a flexible hose; the hub motor lead wires are connected from the waterproof connector; the flexible hoses and lead wires are connected to the inside of the axle body through a second sealing seat, and the second sealing seat is sealed and fixed to the end of the axle body; each of the flexible hoses is connected to the end of the air-cooled output pipeline, the fluid output pipeline, the air-cooled input pipeline, and the fluid input pipeline.

[0005] Furthermore, a sheath is fitted between the first and second sealing seats for the hose body and the lead wire; the hose body is connected to the ends of the air-cooled output pipeline, the fluid output pipeline, the air-cooled input pipeline and the fluid input pipeline via flanges or spiral joints; the lead wire is led out from the top of the flange cover plate via a waterproof joint; the working fluid input end and the working fluid output end are led out from the side of the accommodating chamber.

[0006] Furthermore, the fluid output pipeline and fluid input pipeline are heat transfer oil pipelines or antifreeze pipelines.

[0007] Furthermore, the second fluid heat exchanger is a three-channel heat exchanger; the heat transfer oil pipeline or antifreeze pipeline is connected to two sets of fluid output pipelines and fluid input pipelines respectively.

[0008] Furthermore, the air conditioning system is an independent compressor air conditioning system or a vehicle air conditioning system; the air conditioning system is connected to the central control unit, and a temperature monitoring unit is connected in series on the air-cooled input pipeline and the fluid input pipeline; the temperature monitoring unit, the pump group, the first pump body and the second pump body are connected to the central control unit; the central control unit obtains data on the current vehicle speed, braking force, braking time and circuit temperature, controls the first pump body and the second pump body to operate individually or in combination, and adjusts the output power of the first pump body and the second pump body.

[0009] Furthermore, a replenishment tank is fixed at the top of the first fluid heat exchanger. The replenishment tank is connected to the fluid input pipeline and can replenish heat transfer oil or antifreeze to the fluid input pipeline.

[0010] Furthermore, the unsprung mass dispersion unit includes a reinforcing angle plate, which is integrally cast at both ends of the axle body and is staggered vertically on opposite sides of the axle body; the reinforcing angle plate is provided with multiple flange holes spaced apart; the reinforcing angle plate is connected from the outer edge of the steering seat (steering assembly component) to the middle of the axle body, and can transmit and disperse the lateral centrifugal force at the wheel end to the entire axle body. When high-speed turning generates lateral centrifugal thrust that causes the steering seat (steering assembly component) to move outward of the wheel, the reinforcing angle plate can hold the rear end of the steering seat to counteract the lateral deformation; The beam frame is an inverted U-shaped structure. Flange seats are integrally formed at both ends of the beam frame. The flange seats are fastened to the flange holes by bolts and nuts. A through groove is opened in the middle of the top surface of the beam frame. An inertial damping unit includes a guide sleeve that is fitted and fixed to a through slot. A magnetorheological damper is disposed above the axle body. The telescopic rod of the magnetorheological damper is slidably installed with the guide sleeve. A pull plate is hinged to the bottom of the telescopic rod. A strong spring body is disposed between the pull plate and the guide sleeve on the telescopic rod. The top of the magnetorheological damper is hinged to a spring support via a hinged ball joint. The spring support is fixed to the frame. The hinged ball joint can automatically adapt to axle and frame bumps, loads, etc. The multi-directional micro-displacements caused by thermal expansion and contraction can automatically compensate for the angular deviation between the magnetorheological damper and the frame. The magnetorheological damper can be used for road bump adjustment during the testing phase. The magnetorheological damper, together with the high-strength spring body, can pre-tension and unload, and under normal conditions, share the load of the axle body. The high-strength spring body comes with pre-tension at the factory, and under normal conditions of vehicle no-load and full-load, it continuously lifts upward, which reduces the static bending stress at both ends of the axle body in the long term and is compatible with motor hubs. At the same time, it can eliminate vertical inertial impact force and bump inertial impact.

[0011] Furthermore, the beam frame is integrally formed with multiple reinforcing ribs on its exterior, which can enhance the overall strength of the beam frame.

[0012] Furthermore, the pull plate has multiple through holes, and a guide post is slidably disposed in the through holes. The guide post is fixed to the top surface of the axle body, so that when the pull plate is pulled, it can ensure that the pull plate acts vertically on the axle body.

[0013] Furthermore, the axle body is integrally formed with a slide rail at the bottom of the reinforcing angle plate, and a top block is slidably disposed on the inner side of the slide rail. The top block is disposed outside the wheel hub rotation end. A damping spring body is fixed between the slide rail and the top block. The top block is restricted by the damping spring body and is close to the steering area under normal conditions. During normal turning, the steering assembly does not contact the top block. When high-speed turning generates lateral centrifugal thrust that causes the steering seat (steering assembly component) to displace to the outside of the wheel, the steering assembly abuts against the top block. The top block provides resistance through the damping spring body to counteract the lateral deformation caused by lateral inertia.

[0014] Compared with the prior art, the hub electric drive axle of the present invention has the following advantages: 1. It adopts dual independent cooling circuits of air cooling and liquid cooling. Through the heat exchange core integrated in the middle of the axle body, it exchanges heat with the vehicle air conditioning system. It can perform graded heat dissipation for the wheel hub motor and braking components, efficiently remove heat from the inside of the wheel hub, avoid motor demagnetization, grease evaporation and seal aging caused by high temperature, and improve the operational reliability and service life of the wheel hub electric drive system.

[0015] 2. The axle main structure adopts a centrally integrated cast housing, which integrates heat exchange components, pump body and pipelines inside the axle. The structure is compact and does not occupy additional chassis layout space. At the same time, the axle has high overall bending strength and is suitable for the large unsprung mass characteristics of hub electric drive.

[0016] 3. By using a pre-tensioned, high-strength spring to lift the axle body upwards under normal conditions, the static bending stress at both ends of the axle is reduced over a long period. Combined with a magnetorheological damper, this can quickly dissipate the vertical inertial impact force generated by road bumps, improving ride comfort and axle fatigue resistance. At the same time, through the staggered arrangement of reinforcing corner plates and lateral damping top block structure, the lateral centrifugal force at the wheel ends can be distributed and transmitted to the entire axle body, and lateral damping support can be provided during high-speed cornering to counteract lateral inertial deformation, thereby improving steering accuracy and driving stability.

[0017] 4. The central control unit combines vehicle speed, braking parameters and circuit temperature for intelligent regulation. It can start the air-cooled and liquid-cooled circuits individually or in combination to match the heat dissipation requirements of different driving conditions, taking into account both heat dissipation efficiency and energy consumption control. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the hub electric drive axle of the present invention.

[0019] Figure 2 This is a schematic diagram of the overall structure of the heat exchange core assembly of the present invention.

[0020] Figure 3 This is a schematic diagram of the overall structure of the connector unit of the present invention.

[0021] Figure 4 This is a schematic diagram of the overall structure of the inertial dissipation unit of the present invention.

[0022] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of the hub electric drive axle of the present invention.

[0023] Reference numerals: 1. Axle body; 2. Storage compartment; 3. Flange cover; 4. First medium heat exchanger; 5. Second medium heat exchanger; 6. Insulation pad; 7. Frame beam; 8. First pump body; 9. Second pump body; 10. First output tee; 11. Second output tee; 12. Air-cooled output pipeline; 13. Medium output pipeline; 14. Air-cooled input pipeline; 15. Medium input pipeline; 16. Working medium input end; 17. Working medium output end; 18. Pump unit; 19. Air conditioning system, 20. Connector unit, 21. First sealing seat, 22. Waterproof connector, 23. Pressure check valve, 24. Hose body, 25. Lead wire, 26. Second sealing seat, 27. Sheath, 28. Liquid replenishment tank, 29. Reinforcing angle plate, 30. Beam frame, 31. Guide sleeve, 32. Magnetorheological damper, 33. Pull plate, 34. High-strength spring body, 35. Hinged ball head, 36. Spring support, 37. Reinforcing rib, 38. Guide column, 39. Slide rail, 40. Top block. Detailed Implementation

[0024] Example 1: like Figures 1 to 4 The hub-driven electric axle shown includes an axle body 1, with hub assemblies containing built-in hub motors mounted at both ends of the axle body 1. A housing 2 is integrally cast in the middle of the axle body 1, and a flange cover 3 is bolted to the top of the housing 2. The axle body 1 serves as the load-bearing base, with the housing 2 integrally cast in the middle. The housing 2 has an upward-opening structure, and its top opening is sealed with a flange cover 3 by bolts, achieving protection and sealing of the internal components. It also includes: A heat exchange core assembly is fixed inside the containment chamber 2. The heat exchange core assembly includes a first-flow heat exchanger 4 and a second-flow heat exchanger 5 arranged vertically. A heat insulation pad 6 is provided between the first-flow heat exchanger 4 and the second-flow heat exchanger 5. Multiple frame beams 7 are bolted to the outside of the first-flow heat exchanger 4 and the second-flow heat exchanger 5, and the bottom of the frame beams 7 is bolted to the bottom of the inside of the containment chamber 2. The heat insulation pad 6 isolates the heat transfer between the first-flow heat exchanger 4 and the second-flow heat exchanger 5, preventing interference between different temperature circuits. Multiple frame beams 7 are bolted to the outside of the medium heat exchanger 5. The bottom of the frame beams 7 is bolted to the inner bottom surface of the accommodating chamber 2, achieving a stable installation of the entire heat exchange core assembly. A first pump body 8 and a second pump body 9 are respectively fixed to the heat exchange output ends of the first medium heat exchanger 4 and the second medium heat exchanger 5. A first output tee 10 and a second output tee 11 are respectively connected to the output ends of the first pump body 8 and the second pump body 9. Air-cooled output pipelines 12 are connected to both ends of the first output tee 10, and medium output pipelines 13 are connected to both ends of the second output tee 11. The heat exchange input ends of the first medium heat exchanger 4 and the second medium heat exchanger 5 are respectively connected to a first input tee and a second input tee; the first input tee is connected to an air-cooled input pipeline 14 at both ends, and the second input tee is connected to a medium input pipeline 15 at both ends; the first medium heat exchanger 4 and the second medium heat exchanger 5 are respectively provided with an industrial medium input end 16 and an industrial medium output end 17 on opposite sides; the industrial medium input end 16 is connected to the air conditioning system 19 through a pump set 18; the air-cooled output pipeline 12, the medium output pipeline 13, the air-cooled input pipeline 14, and the medium input pipeline 15 are... Extending from the inside of the axle body 1 to both ends; two air-cooled output lines 12 and two air-cooled input lines 14 extend to both ends of the axle body respectively; two liquid-cooled output lines 13 and two liquid-cooled input lines 15 also extend to the left and right ends of the axle body 1; the working medium input end 16 is connected to the air conditioning system 19 through an external pump set 18. The low-temperature working medium output by the air conditioning system 19 enters the first liquid-cooled heat exchanger 4 and the second liquid-cooled heat exchanger 5, and exchanges heat with the medium of the air-cooled circuit and the liquid-cooled circuit. The heated working medium flows back to the air conditioning system 19 from the working medium output end 17 to form a refrigeration cycle. The connector unit 20 is used to achieve a transition connection and seal between the cooling pipeline and the motor lead wire. The connector unit 20 includes a first sealing seat 21 fitted and fixed at the center of the stator of the hub motor, with a waterproof connector 22 fixed at the center of the first sealing seat 21. Four sets of pressure check valves 23 are fixed to the side of the first sealing seat 21 near the hub motor. Two sets of pressure check valves 23 are connected to the hub motor cooling pipeline, forming a liquid cooling circuit. The other two sets of pressure check valves 23 are hollow at one end, forming a wind cooling circuit. A flexible hose 24 is fixed to the other end of the four sets of pressure check valves 23. The flexible hose 24 is made of heat-resistant and bend-resistant flexible tubing, adaptable to the displacement caused by wheel steering and bouncing. The hub motor lead wire 25 is connected to the waterproof connector. Connector 22 leads out; the flexible hose 24 and lead wire 25 are connected to the inside of the axle body 1 through the second sealing seat 26, and the second sealing seat 26 is sealed and fixed to the end of the axle body 1; each of the flexible hoses 24 is connected to the end of the air-cooled output pipeline 12, the fluid output pipeline 13, the air-cooled input pipeline 14, and the fluid input pipeline 15; a sheath 27 is sleeved between the flexible hose 24 and the lead wire 25 and the first sealing seat 21 and the second sealing seat 26; the flexible hose 24 is connected to the end of the air-cooled output pipeline 12, the fluid output pipeline 13, the air-cooled input pipeline 14, and the fluid input pipeline 15 through a flange or spiral connector; the lead wire 25 is led out from the top of the flange cover plate 3 through the waterproof connector 22; the working fluid input end 16 and the working fluid output end 17 are led out from the side of the accommodating chamber 2. During installation, the flexible hose 24 and the motor lead wire 25 pass through the second sealing seat 26 and enter the inner cavity of the axle body 1. The second sealing seat 26 is sealed and fixed to the end of the axle body 1 to achieve sealing protection of the axle end. The section between the flexible hose 24 and the lead wire 25 between the first sealing seat 21 and the second sealing seat 26 is covered with a sheath 27, which protects and bundles the pipeline and wire harness. The ends of each flexible hose 24 are respectively connected to the ends of the air-cooled output pipeline 12, the fluid output pipeline 13, the air-cooled input pipeline 14, and the fluid input pipeline 15 on the same side. The flexible hose 24 is fastened to the rigid pipeline through a flange joint or a spiral joint to ensure reliable sealing. After the motor lead wire 25 is routed from inside the axle, it is led out to the vehicle controller through the waterproof joint 22 on the flange cover plate 3. The working fluid input end 16 and the working fluid output end 17 are led out from the side of the accommodating compartment 2 for easy connection to the vehicle air conditioning pipeline.

[0025] The fluid output line 13 and fluid input line 15 are heat transfer oil lines or antifreeze lines.

[0026] The second medium heat exchanger 5 is a three-channel heat exchanger; the heat transfer oil pipeline or antifreeze pipeline is connected to two sets of medium output pipelines 13 and medium input pipelines 15 respectively; the second medium heat exchanger 5 adopts a three-channel heat exchanger, the medium output pipeline 13 and the medium input pipeline 15 adopt heat transfer oil pipelines or antifreeze pipelines, and the heat transfer oil and antifreeze circuits on the left and right sides are independently connected to the three-channel heat exchanger to ensure that the cooling circuits on both sides exchange heat independently.

[0027] The air conditioning system 19 is either an independent compressor air conditioning system 19 or a vehicle air conditioning system 19. The air conditioning system 19 is connected to the central control unit. A temperature monitoring unit is connected in series on the air-cooled input pipeline 14 and the fluid input pipeline 15. The temperature monitoring unit, the pump group 18, the first pump body 8 and the second pump body 9 are connected to the central control unit. The central control unit acquires data on the current vehicle speed, braking force, braking time and circuit temperature, controls the first pump body 8 and the second pump body 9 to operate individually or in combination, and adjusts the output power of the first pump body 8 and the second pump body 9.

[0028] The first fluid heat exchanger 4 has a liquid replenishment tank 28 fixed on top. The liquid replenishment tank 28 is connected to the fluid input pipeline 15 and is used to replenish heat transfer oil or antifreeze to the liquid cooling circuit, compensate for pipeline losses, and maintain stable circuit pressure.

[0029] The unsprung mass dispersion unit includes a reinforcing angle plate 29, which is integrally cast at both ends of the axle body 1 and is staggered vertically on opposite sides of the axle body 1. The reinforcing angle plate 29 has multiple flange holes spaced apart. The reinforcing angle plate 29 is connected from the outer edge of the steering seat (steering assembly component) to the middle of the axle body 1, and can transmit and disperse the lateral centrifugal force at the wheel end to the entire axle body 1. When high-speed turning generates lateral centrifugal thrust that causes the steering seat (steering assembly component) to move outward of the wheel, the reinforcing angle plate 29 can hold the rear end of the steering seat to counteract lateral deformation. The beam frame 30 has an inverted U-shaped structure. Flange seats are integrally formed at both ends of the beam frame 30. The flange seats are fastened to the flange holes by bolts and nuts. A through groove is opened in the middle of the top surface of the beam frame 30. An inertial dissipation unit includes a guide sleeve 31 that is fitted and fixed to a through slot. A magnetorheological damper 32 is disposed above the axle body 1. The telescopic rod of the magnetorheological damper 32 is slidably installed with the guide sleeve 31. A pull plate 33 is hinged to the bottom of the telescopic rod of the magnetorheological damper 32. A strong spring body 34 is disposed between the pull plate 33 and the guide sleeve 31 on the telescopic rod of the magnetorheological damper 32. The top of the magnetorheological damper 32 is hinged to a spring support 36 via a hinged ball joint 35. The spring support 36 is fixed to the vehicle frame. The hinged ball joint 35 can automatically adapt to the vehicle. The multi-directional micro-displacements caused by bridge and frame bumps, loads, and thermal expansion and contraction can be automatically compensated for by the magnetorheological damper 32 and the frame. The magnetorheological damper 32 can be used for road bump adjustment during the testing phase. The magnetorheological damper 32 and the high-strength spring body 34 work together to pre-tension and unload, and share the load of the axle body 1 under normal conditions. The high-strength spring body 34 is pre-tensioned at the factory, and continuously lifts upward under normal conditions of vehicle no-load and full-load, which reduces the static bending stress at both ends of the axle body 1 in the long term and is compatible with motor hubs. At the same time, it can eliminate vertical inertial impact force and bump inertial impact.

[0030] The beam frame 30 is integrally formed with multiple reinforcing ribs 37 on its exterior, which can enhance the overall strength of the beam frame 30.

[0031] The pull plate 33 has multiple through holes, and a guide post 38 is slidably disposed in the through holes. The guide post 38 is fixed to the top surface of the axle body 1 so that when the pull plate 33 is pulled, it can ensure that the pull plate 33 acts vertically on the axle body 1.

[0032] Example 2: like Figure 5 The hub-driven electric axle shown has a slide rail 39 integrally formed on the bottom of the reinforcing angle plate 29 of the axle body 1. A top block 40 is slidably disposed on the inner side of the slide rail 39 and is disposed outside the hub rotation end. A damping spring is fixed between the slide rail 39 and the top block 40. The top block 40 is restricted by the damping spring and is close to the steering area under normal conditions. During normal turning, the steering assembly does not contact the top block 40. When high-speed turning generates lateral centrifugal thrust that causes the steering seat (steering assembly component) to displace to the outside of the wheel, the steering assembly abuts against the top block 40. The top block 40 provides resistance through the damping spring to counteract the lateral deformation caused by lateral inertia.

[0033] The heat dissipation circuit of the hub electric drive axle of the present invention operates as follows: By setting up dual independent air-cooled and liquid-cooled circuits, the central control unit collects data on current vehicle speed, braking force, braking time, and circuit temperature. The operating mode is dynamically adjusted through a built-in multi-parameter coupled heat dissipation control model, specifically as follows: The central control unit's built-in heat dissipation control model uses real-time vehicle speed, brake pedal opening, braking duration, air-cooled circuit return air temperature, and liquid-cooled circuit return liquid temperature as input variables, and the output control quantities are the output power of the first pump body 8, the second pump body 9, and the air conditioning side pump group 18. The heat dissipation control model presets three operating modes and a first-level over-temperature protection mechanism. The switching between modes is based on a joint determination of temperature and operating condition thresholds: when the return liquid temperature is lower than the first set threshold and the vehicle is in a state of... Under constant speed and low load conditions, this is considered a low load normal, and only the single-cycle air-cooled circuit is activated. When the return fluid temperature is between the first and second set thresholds, or when the vehicle is under continuous braking or climbing conditions, this is considered a medium load condition, and both the air-cooled and liquid-cooled circuits are activated simultaneously, with the pump operating at base power. When the return fluid temperature is higher than the second set threshold, or when the brake opening is greater than the set value and the duration exceeds the set time, this is considered a high load condition, increasing the power of the dual-circuit pump and the air conditioning cooling power to enhance heat exchange efficiency. When the return fluid temperature exceeds the protection threshold, the over-temperature protection mechanism is triggered, and the central control unit sends a power reduction signal to the vehicle controller, limiting the output torque of the wheel hub motors, while the cooling system operates at full power. Until the temperature drops back to a safe range; based on the graded mode, the heat dissipation control model introduces closed-loop temperature regulation, which collects the deviation between the circuit temperature and the target temperature in real time, and dynamically corrects the pump speed and air conditioning pump displacement through proportional, integral and derivative operations to achieve precise and stable temperature control and avoid large temperature fluctuations; the heat dissipation control model adjusts the heat dissipation power in advance according to changes in driving conditions, for example, when braking is detected, the power of the liquid cooling circuit pump is increased in advance to cope with the instantaneous temperature rise caused by braking and improve the temperature response speed; when the vehicle is driving at a low constant speed and the wheel hub motor generates less heat, the central control unit only activates the air cooling circuit. At this time, the first pump 8 is activated, driving the air circulation in the air cooling circuit: low temperature air After being pressurized by the first pump body 8, the air is evenly distributed to the two air-cooled output pipelines 12 through the first output tee 10. It then runs through the internal wiring of the axle body 1 to the two end connector units 20. Through the hose body 24 and the pressure check valve 23, it is blown into the internal cavity of the wheel hub motor, directly blowing on the motor stator and windings, and carrying away the heat generated by the motor. The heated air flows back from the other side air-cooled input pipeline 14, and after being collected by the first input tee, it enters the first flow medium heat exchanger 4, where it exchanges heat with the low-temperature working fluid input by the air conditioning system 19. The cooled air then enters the first pump body 8 again, completing the air-cooling cycle. In this mode, the air directly contacts the heat-generating components of the motor for heat exchange. The structure is simple, the energy consumption is low, and it meets the heat dissipation requirements of normal driving conditions.

[0034] When the vehicle is traveling at high speed, climbing hills for a long time, or braking frequently, the heat generated by the hub motor and brakes increases significantly. The central control unit simultaneously activates the air-cooling circuit and the liquid-cooling circuit for dual-circuit combined heat dissipation. When the liquid-cooling circuit is running, the second pump body 9 starts, driving the heat transfer oil or antifreeze to circulate. The low-temperature cooling medium is pressurized by the second pump body 9 and distributed to the two flow medium output lines 13 through the second output tee 11. It then enters the cooling lines inside the hub motor through the hose body 24 and the pressure check valve 23, where it exchanges heat over a large area with the motor stator and brake mounting base, quickly removing a large amount of heat. The heated cooling medium flows back from the flow medium input line 15, is collected by the second input tee, and enters the second flow medium heat exchanger 5, where it exchanges heat with the low-temperature working fluid of the air conditioning system 19 to cool down. After that, it re-enters the second pump body 9 for circulation. Meanwhile, the air-cooled circuit continues to operate, enhancing air convection and promptly removing the radiant heat from the braking components. The central control unit collects the return liquid temperature in real time through the temperature monitoring unit and dynamically adjusts the output power of the first pump body 8 and the second pump body 9, as well as the cooling power of the air conditioning system 19, based on the temperature level, optimizing energy consumption while ensuring heat dissipation. When the braking intensity is extremely high and the temperature rise rate exceeds the threshold, the central control unit can increase the speed of the pump group 18 and the air conditioning cooling power, entering the extreme heat dissipation mode to quickly suppress the temperature peak and prevent the motor from overheating. The pressure check valve 23 ensures stable pressure within the circuit, preventing pipeline pressure fluctuations from affecting the cooling effect. At the same time, it can prevent fluid overflow and seal failure in the event of pipeline damage. The replenishment tank 28 replenishes the liquid cooling circuit with medium in real time, maintaining stable liquid level and pressure in the circuit.

[0035] The working process of the unsprung mass dispersion unit of the present invention is as follows: Vertical load bearing and inertia relief process: When the vehicle is stationary or moving smoothly, the high-strength spring body 34 is in a pre-compressed state, applying an upward pulling force to the axle body 1 through the pull plate 33, offsetting part of the self-weight of the axle and wheel hub assembly, reducing the static bending stress at the axle fist positions at both ends of the axle, adapting to the large unsprung mass brought by the wheel hub electric drive, and improving the fatigue life of the axle; when the vehicle travels over a bumpy road surface and the axle generates vertical bounce, the axle body 1 moves up and down relative to the frame, and the pull plate 33 slides vertically along the guide post 38, strongly... The force spring body 34 is further compressed or rebounded to absorb some of the impact energy; at the same time, the magnetorheological damper 32 adjusts the damping force in real time according to the control signal input from the central control unit, quickly attenuating vertical vibration, dissipating the inertial force generated by road impact, improving ride comfort, and avoiding rigid impact on the axle; the articulated ball joint 35 can adapt to the angular deviation generated during axle bounce, avoiding the damper from bearing lateral bending moment; the damping parameters of the magnetorheological damper 32 can be matched through vehicle tuning to adapt to the suspension characteristics of different models; Lateral deformation resistance process: When the vehicle is turning at normal low speed, the lateral force at the wheel end is low, the steering assembly will not contact the top block 40, and the steering action is not interfered with; when the vehicle is turning at high speed, the wheel end bears a large lateral centrifugal force, and the steering assembly tends to displace to the outside of the wheel; at this time, the reinforcing angle plate 29 first disperses and transmits the lateral force at the wheel end to the middle area of ​​the axle body 1, reducing the local stress at the axle fist; if the lateral force increases further, the steering assembly will produce a small deformation outward and abut against the top block 40, the top block 40 compresses the damping spring body, the damping spring body provides a reverse damping force, counteracts the deformation tendency caused by lateral inertia, limits the lateral displacement of the steering knuckle, thereby improving the steering accuracy and driving stability when turning at high speed, and avoiding permanent lateral deformation of the axle; Vehicle matching and calibration process: During the vehicle matching stage, this axle can be systematically calibrated to adapt to the load-bearing requirements and driving characteristics of different vehicle models. The calibration process includes vertical performance calibration, lateral performance calibration, and cooling system calibration. Vertical performance calibration is divided into two stages: bench calibration and actual vehicle calibration. In the bench calibration stage, the axle body 1 is fixed on a vibration test bench, and a standard load is applied to the spring support 36. First, the pre-compression of the strong spring body 34 is adjusted by adding or removing shims between the guide sleeve 31 and the through groove to change the initial installation distance and set the corresponding preload. The static bending stress at both ends of the axle was reduced to within the design threshold range, completing the static load adjustment. Then, vertical vibration excitations of different frequencies and amplitudes were input to the test bench, and the axle vibration acceleration and damper telescopic rod displacement were simultaneously collected. The damping current and damping force mapping parameters of the magnetorheological damper 32 were adjusted accordingly, establishing a mapping table between vibration amplitude, vibration frequency, and damping current, which was stored in the central control unit. This allows the damper to match the optimal damping force in real time according to the road surface excitation, completing the basic damping calibration. In the actual vehicle calibration phase, actual vehicle driving tests were conducted on different grades of road surfaces. Tests were conducted, collecting vertical vibration data of the axle and vibration data of the chassis. The damping response gradient and trigger threshold in the mapping table were fine-tuned to optimize the damping response speed, balancing ride comfort and load-bearing reliability. The initial angle of the articulated ball joint 35 could be adjusted using the mounting shims of the spring support 36 to compensate for installation errors in the chassis and axle, ensuring the damper is always at its optimal stress angle. Lateral performance tuning primarily focused on matching the lateral support characteristics during high-speed cornering: during bench testing, graded lateral loads were applied to the wheel ends, and the lateral displacement of the steering knuckle and the stress on the reinforcing angle plate 29 were collected. Force data was first used to verify the force transmission effect of the reinforcing angle plate 29, ensuring that the lateral force could be effectively distributed to the axle body 1. Then, the initial preload and stiffness specifications of the damping spring were adjusted so that the top block 40 would start to contact and provide damping support under the set lateral load threshold, ensuring no interference during normal steering and providing sufficient support stiffness under high speed and large lateral force. In the actual vehicle tuning stage, turning tests at different vehicle speeds and steering angles were conducted to collect parameters such as vehicle roll angle and steering response delay, and the damping spring parameters were fine-tuned to match the steering feel and driving stability requirements of the whole vehicle. During the calibration phase of the heat dissipation system, temperature rise tests were conducted under the rated operating conditions, peak operating conditions, and continuous braking conditions of the hub motor. Data on the temperature of the hub motor windings, the brake, and the circuit medium were collected. The temperature threshold, pump power mapping parameters, and air conditioning cooling capacity matching parameters in the heat dissipation control model were then corrected accordingly to ensure that the internal temperature of the hub is within a safe operating range under each operating condition.

[0036] The above embodiments are merely preferred embodiments of the present invention. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention are included within the scope of the present invention.

Claims

1. A hub-driven electric axle, comprising an axle body, wherein hub assemblies with built-in hub motors are mounted at both ends of the axle body, characterized in that: The axle body has an integrally cast accommodating chamber in the middle, and a flange cover plate is bolted to the top of the accommodating chamber; unsprung mass dispersion units are provided at both ends of the axle body; it also includes: A heat exchange core assembly is fixed inside the containment chamber. The heat exchange core assembly includes a first medium heat exchanger and a second medium heat exchanger arranged vertically. A heat insulation pad is provided between the first and second medium heat exchangers. Multiple frame beams are bolted to the exterior of the first and second medium heat exchangers, and the bottom of the frame beams is bolted to the bottom of the containment chamber. A first pump body and a second pump body are respectively fixed to the heat exchange output ends of the first and second medium heat exchangers. A first output tee and a second output tee are respectively connected to the output ends of the first and second pump bodies. The two ends of the first output tee are connected to... The axle is equipped with an air-cooled output pipeline, and the second output tee is connected to two ends of a medium output pipeline. The heat exchange input ends of the first and second medium heat exchangers are respectively connected to a first input tee and a second input tee. The first input tee is connected to two ends of an air-cooled input pipeline, and the second input tee is connected to two ends of a medium input pipeline. The first and second medium heat exchangers are respectively provided with an industrial medium input end and an industrial medium output end on opposite sides. The industrial medium input end is connected to the air conditioning system through a pump set. The air-cooled output pipeline, the medium output pipeline, the air-cooled input pipeline, and the medium input pipeline extend from the inside of the axle body to both ends. The connector unit includes a first sealing seat that is fitted and fixed at the center of the stator of the hub motor, and a waterproof connector is fixed at the center of the first sealing seat; four sets of pressure check valves are fixed on the side of the first sealing seat near the hub motor, two sets of pressure check valves are connected to the hub motor cooling pipeline; one end of the other two sets of pressure check valves is hollow, and the other end of the four sets of pressure check valves is fixed with a flexible hose; the hub motor lead wires are connected from the waterproof connector; the flexible hoses and lead wires are connected to the inside of the axle body through a second sealing seat, and the second sealing seat is sealed and fixed to the end of the axle body; each of the flexible hoses is connected to the end of the air-cooled output pipeline, the fluid output pipeline, the air-cooled input pipeline, and the fluid input pipeline.

2. The hub electric drive axle according to claim 1, characterized in that: The hose body and the lead wire are fitted with a sheath between the first and second seals; the hose body is connected to the ends of the air-cooled output pipeline, the fluid output pipeline, the air-cooled input pipeline, and the fluid input pipeline via flanges or spiral joints; the lead wire is led out from the top of the flange cover plate via a waterproof joint; the working fluid input end and the working fluid output end are led out from the side of the containment chamber.

3. The hub electric drive axle according to claim 1, characterized in that: The fluid output pipeline and fluid input pipeline are heat transfer oil pipelines or antifreeze pipelines.

4. The hub electric drive axle according to claim 1, characterized in that: The second fluid heat exchanger is a three-channel heat exchanger; the heat transfer oil pipeline or antifreeze pipeline is connected to two sets of fluid output pipelines and fluid input pipelines respectively.

5. The hub electric drive axle according to claim 1, characterized in that: The air conditioning system is either an independent compressor air conditioning system or a vehicle air conditioning system; the air conditioning system is connected to the central control unit, and a temperature monitoring unit is connected in series on the air-cooled input pipeline and the fluid input pipeline; the temperature monitoring unit, the pump group, the first pump body and the second pump body are connected to the central control unit.

6. The hub electric drive axle according to claim 1, characterized in that: The first fluid heat exchanger has a replenishment tank fixed at the top, and the replenishment tank is connected to the fluid input pipeline.

7. The hub electric drive axle according to claim 1, characterized in that: The unsprung mass dispersion unit includes: The reinforcing angle plate is integrally cast at both ends of the axle body and is staggered vertically on opposite sides of the axle body; the reinforcing angle plate is provided with multiple flange holes spaced apart. The beam frame is an inverted U-shaped structure. Flange seats are integrally formed at both ends of the beam frame. The flange seats are fastened to the flange holes by bolts and nuts. A through groove is opened in the middle of the top surface of the beam frame. An inertial dissipation unit includes a guide sleeve that is fitted and fixed to a through slot. A magnetorheological damper is disposed above the axle body. The telescopic rod of the magnetorheological damper is slidably installed with the guide sleeve. A pull plate is hinged to the bottom of the telescopic rod of the magnetorheological damper. A strong spring body is disposed between the pull plate and the guide sleeve on the telescopic rod of the magnetorheological damper. The top of the magnetorheological damper is hinged to a spring support through a hinged ball joint. The spring support is fixed to the vehicle frame.

8. The hub electric drive axle according to claim 7, characterized in that: The beam frame is integrally formed with multiple reinforcing ribs on its exterior.

9. The hub electric drive axle according to claim 7, characterized in that: The pull plate has multiple through holes, and a guide post is slidably disposed in the through hole. The guide post is fixed to the top surface of the axle body.

10. The hub electric drive axle according to claim 7, characterized in that: The axle body is integrally formed with a slide rail at the bottom of the reinforcing angle plate. A top block is slidably arranged on the inner side of the slide rail, and the top block is located outside the wheel hub rotation end. A damping spring body is fixed between the slide rail and the top block.

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