Electric wheel drive assembly with integrated inflation and deflation passage, method for controlling the air pressure of a vehicle tire

Abstract

An electric wheel drive assembly with integrated inflation and deflation channels includes a hub motor, a planetary reducer connected to the hub motor, and a wheel hub fixed to the output end of the planetary reducer. The assembly is characterized by an inflation and deflation channel formed on the hub motor, extending forward through the planetary reducer to the wheel hub and connecting to the tire valve on the wheel hub. A parking brake for braking protection during parking is installed at the rear end of the hub motor, and a service brake for braking during driving is installed at the front end. This invention allows for automatic tire inflation, deflation, or pressure maintenance via a pneumatic system controlled by the inflation and deflation channels while the vehicle is in motion. The inflation and deflation channels are integrated within the electric wheel drive assembly, occupying no external space and requiring no additional components. The structure is simple and highly integrated, meeting the requirements of compact, modular, and lightweight electric wheel drive structures. This invention also provides a method for controlling automotive tire pressure.

Description

Technical Field

[0001] This invention relates to an electric wheel drive assembly with integrated inflation and deflation channels, belonging to the field of electric wheel drive technology. This invention also relates to a method for controlling tire pressure in automobiles. Background Technology

[0002] With the rapid development of the electric vehicle industry, the structural design of electric vehicle drive systems has become increasingly diversified. Currently, the drive system structure of electric vehicles is mainly centralized, with the electric motor replacing the original engine. This system configuration is simple and easy to implement, but the power flow from the motor to the wheels requires passing through reducers, differentials, drive shafts, and other transmission mechanisms, resulting in some power loss and relatively low transmission efficiency. Furthermore, the overall system integration, modularity, and lightweighting are relatively low. Benefiting from the flexibility of electrical component placement, distributed drive has become a hot research topic in electric drive systems. It uses two or more drive motors to independently drive their respective wheels, eliminating the differential mechanism, shortening the transmission chain length, and reducing the power and torque requirements of individual motors. This facilitates system integration, lightweighting, and modular design. However, electric wheel drive still has the following disadvantages: 1. To improve the installation flexibility of electric drive wheels, achieve a more compact layout, higher energy conversion efficiency, and increase the driving range of electric vehicles, research on electric wheel technology has received increasing attention in recent years. However, the high integration of electric wheel devices has brought considerable challenges to the design and integration of automatic tire inflation / deflation systems. Currently, some high-end models in the traditional vehicle field are equipped with tire pressure monitoring systems to remind the driver to inflate or deflate tires when the tire pressure is unsafe, but these systems cannot achieve automatic inflation / deflation. Some devices require additional components to achieve automatic inflation / deflation, but these have drawbacks such as complex structure, low integration, and applicability only to traditional vehicles with ample space. However, a complete automatic tire inflation / deflation system has not yet emerged in the field of electric wheel drive vehicles.

[0003] 2. The high power density electric drive wheel structure still lacks consideration for the miniaturization and weight reduction of the electric drive wheel as a whole, so further research and improvement are needed. Summary of the Invention

[0004] The electric wheel drive assembly with integrated inflation and deflation channels provided by this invention uses a pneumatic system to control the inflation and deflation channels to inflate, deflate, or maintain tire pressure while the vehicle is in motion, achieving automatic tire inflation and deflation during vehicle operation. The inflation and deflation channels are located within the electric wheel drive assembly and do not occupy external space, requiring no additional components. The structure is simple and highly integrated, meeting the requirements of compact, modular, and lightweight electric wheel drive structures. This invention also provides a method for controlling automotive tire pressure.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: An electric wheel drive assembly with integrated air inlet / outlet channels includes a hub motor, a planetary reducer connected to the hub motor, and a wheel hub fixed to the output end of the planetary reducer. The hub motor has an air inlet / outlet channel extending forward through the planetary reducer to the wheel hub and connecting to the tire valve on the wheel hub. The hub motor has a parking brake at its rear end for braking protection when parked and a service brake at its front end for braking when driving.

[0006] Preferably, the hub motor includes a rear end cover connected to the vehicle frame, a housing coaxially fixed to the rear end cover, a front end cover coaxially fixed to the housing, a stator coaxially fixed in the housing, and a rotor cooperating with the stator. The rear end of the rotor is supported by the rear end cover, and the front end is supported by the front end cover. The parking brake is a disc electronic parking brake, and the rear end of the rotor extends out of the rear end cover and is splinedly connected to the parking brake.

[0007] Preferably, the planetary reducer includes a primary planetary drive splined to the front end of the rotor and a secondary planetary drive splined to the primary planetary drive. The primary and secondary planetary drives share a gear ring, which is integrally formed with the front end cover. The hub is fixed to the planet carrier in the secondary planetary drive.

[0008] Preferably, the primary planetary transmission includes a primary sun gear splined to the front end of the rotor, primary planet gears meshing with the primary sun gear, a primary planet carrier assembling the primary planet gears, and a gear ring meshing with the primary planet gears and integrally formed with the front end cover. The secondary planetary transmission includes a secondary sun gear splined to the primary planet carrier, secondary planet gears meshing with the secondary sun gear, and a secondary planet carrier assembling the secondary planet gears. The gear ring meshes with the secondary planet gears, and the hub is coaxially fixed with the secondary planet carrier.

[0009] Preferably, the service brake includes a brake disc fixed coaxially with the wheel hub, and a hydraulic brake caliper mounted on the front end cover and cooperating with the brake disc. The hydraulic brake caliper is connected to the vehicle's hydraulic system via an oil pipe.

[0010] Preferably, the hydraulic brake caliper includes a brake seat coaxially fixed on the front end cover, a piston chamber 1 opened on the front end cover, a brake pad 1 cooperating with the piston chamber 1, a piston chamber 2 opened on the brake seat, and a brake pad 2 cooperating with the piston chamber 2. The piston chamber 1 and the piston chamber 2 are respectively connected to the vehicle's hydraulic system through oil pipes. The brake disc is disposed between the brake pad 1 and the brake pad 2. The brake pad 1 moves and contacts or separates from the brake disc as oil enters the piston chamber 1, and the brake pad 2 moves and contacts or separates from the brake disc as oil enters the piston chamber 2.

[0011] Preferably, the rear end of the gear ring is coaxially fixed to the front end cover, the front end is coaxially fixed to the reducer end cover, the secondary planetary carrier includes a front half carrier fixed to the hub and a rear half carrier fixed behind the front half carrier, the reducer end cover is supported on the front half carrier by the front hub bearing, the front half carrier and the rear half carrier are respectively supported on the primary planetary carrier by bearings, and the gear ring is supported on the rear half carrier by the rear hub bearing.

[0012] Preferably, the charging / discharging air passages include a rear cover air passage on the rear cover, a housing air passage on the housing, a front cover air passage on the front cover, a gear ring air passage on the gear ring, a reducer end cover air passage on the reducer end cover, and a hub air passage on the hub. The rear cover air passage, housing air passage, front cover air passage, gear ring air passage, and reducer end cover air passage are connected sequentially from back to front. The reducer end cover air passage is connected to the hub air passage, and the hub air passage is connected to the air nozzle.

[0013] Preferably, the hub is a cylindrical shape with a rearward opening, fitted over the gear ring and the reducer end cover, forming an annular space between the hub and the reducer end cover. A filling / draining oil seal is provided in the annular space and pressed against the inner wall of the hub. The filling / draining oil seal has an annular sealing chamber. The reducer end cover air passage is connected to the inner end of the annular sealing chamber, and the hub air passage is connected to the outer end of the annular sealing chamber.

[0014] The method for controlling tire pressure in automobiles uses an electric wheel drive assembly with an integrated inflation / deflation channel as described above to control tire pressure. Its features include: connecting the inflation / deflation channel to the vehicle's pneumatic system; and controlling the inflation / deflation channel to inflate, deflate, or maintain tire pressure through the pneumatic system based on real-time tire pressure monitoring data while the vehicle is in motion.

[0015] The beneficial effects of the invention are: 1. The electric wheel drive assembly with integrated inflation and deflation channels of the present invention has inflation and deflation channels on the hub motor. The inflation and deflation channels extend forward through the planetary reducer to the wheel hub and connect with the tire valve. An inflation and deflation channel from rear to front is formed inside the electric wheel drive assembly. The inflation and deflation channels are connected to the vehicle's pneumatic system. Based on real-time monitoring data of tire pressure, the pneumatic system controls the inflation and deflation channels to inflate, deflate, or maintain pressure of the tires while the vehicle is in motion, realizing the function of automatic inflation and deflation of the tires while the vehicle is in motion. The inflation and deflation channels are located inside the electric wheel drive assembly and do not occupy external space. No additional components are required. The structure is simple and highly integrated, meeting the requirements of compact, modular, and lightweight electric wheel drive structure. The parking brake is installed at the rear end of the hub motor, and the service brake is installed at the front end of the hub motor. The service brake and parking brake are designed separately to ensure the safety of the vehicle during driving and parking under high-speed and high-torque conditions.

[0016] 2. The planetary reducer employs a two-stage planetary transmission, offering high load-bearing capacity and a small footprint. It is suitable for rims of 20 inches and larger, making it ideal for electric wheel drives in heavy-duty vehicles. The integrated design of the planetary reducer's gear ring and the front cover of the hub motor effectively reduces the overall assembly space, improving structural sealing and compactness. The rotor's front end is splinedly connected to the first-stage sun gear, allowing for a certain amount of radial float during operation. The second-stage sun gear is splinedly connected to the first-stage planetary carrier, also allowing for a certain amount of radial float during operation. This reduces noise from uneven load distribution and manufacturing errors in the planetary gear set, while also extending the lifespan of the planetary gear set. The second-stage planetary carrier features a split design, facilitating machining and assembly. The reducer end cover is fixed to the front of the gear ring, which is supported on the second-stage planetary carrier via a front hub bearing. The gear ring is supported on the second-stage planetary carrier via a rear hub bearing, allowing the hub to rotate and connect to the gear ring through the hub bearing. This allows the load to be transferred to the frame via the front cover, housing, and rear cover, providing high load-bearing capacity to meet the demands of high-torque, heavy-load applications. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an electric wheel drive assembly with integrated charging and discharging air passages in a specific embodiment.

[0018] Figure 2 for Figure 1 A magnified view of a portion of the image.

[0019] Figure 3 A schematic diagram of the electric wheel drive assembly with the charging / discharging air passages integrated into it. Detailed Implementation

[0020] The following is combined with Figures 1-3 The embodiments of the present invention will be described in detail below.

[0021] An electric wheel drive assembly with integrated air inlet / outlet channels includes a hub motor 1, a planetary reducer 2 connected to the hub motor 1, and a wheel hub 3 fixed to the output end of the planetary reducer 2. The hub motor 1 has an air inlet / outlet channel 4 that extends forward through the planetary reducer 2 to the wheel hub 3 and connects with the tire valve 5 on the wheel hub 3. The hub motor 1 has a parking brake 6 at its rear end for braking protection when parked and a service brake 7 at its front end for braking when driving.

[0022] The electric wheel drive assembly with integrated inflation and deflation channels described above has an inflation and deflation channel 4 on the hub motor 1. The inflation and deflation channel 4 extends forward through the planetary reducer 2 to the wheel hub 3 and connects with the tire valve 5. An inflation and deflation channel 4 is formed inside the electric wheel drive assembly from rear to front. The inflation and deflation channel 4 is connected to the vehicle's pneumatic system. Based on real-time monitoring data of tire pressure, the pneumatic system controls the inflation and deflation channel to inflate, deflate, or maintain pressure of the tires while the vehicle is in motion, realizing the function of automatically inflating and deflating the tires while the vehicle is in motion. The inflation and deflation channel 4 is located inside the electric wheel drive assembly and does not occupy external space. It does not require additional components, has a simple structure, and a high degree of integration, meeting the requirements of compact, modular, and lightweight electric wheel drive structure. The parking brake 6 is installed at the rear end of the hub motor 1, and the service brake 7 is installed at the front end of the hub motor. The service brake 7 and the parking brake 6 are designed separately to ensure the safety of the vehicle during driving and parking under high-speed and high-torque conditions.

[0023] The hub motor 1 includes a rear end cover 101 connected to the vehicle frame, a housing 102 coaxially fixed to the rear end cover 101, a front end cover 103 coaxially fixed to the housing 102, a stator 104 coaxially fixed in the housing 102, and a rotor 105 cooperating with the stator 104. The rear end of the rotor 105 is supported by the rear end cover 101, and the front end is supported by the front end cover 103. The parking brake 6 is a disc electronic parking brake. The rear end of the rotor 105 extends out of the rear end cover 101 and is splinedly connected to the parking brake 6. The rear cover 101, housing 102 and front cover 103 form the housing of the hub motor 1. The rear end of the rotor 105 extends out of the rear cover 101 and is splinedly connected to the parking brake 6. The brake disc of the parking brake 6 is engaged with the rear spline of the rotor 105 and moves together with the rotor. The brake caliper of the parking brake 6 is mounted on the rear cover 101. When the brake caliper of the parking brake 6 presses against its brake disc, it restricts the rotation of the rotor and provides safety assurance for parking the entire vehicle.

[0024] The planetary reducer 2 includes a primary planetary drive 21 splinedly connected to the front end of the rotor 105 and a secondary planetary drive 22 splinedly connected to the primary planetary drive 21. The primary and secondary planetary drives 21 share a common gear ring, which is integrally formed with the front end cover 103. The wheel hub 3 is fixed to the planet carrier in the secondary planetary drive 22. The planetary reducer 2 employs a two-stage planetary drive, offering high load-bearing capacity and a small footprint. It is suitable for rims of 20 inches and above, making it ideal for electric wheel drives in heavy-duty vehicles. The shared gear ring, integrally formed with the front end cover 103, does not rotate. Torque is transmitted from the primary planetary drive to the planet carrier of the secondary planetary drive, driving the wheel hub 3 to rotate and thus driving the wheel. The integrated design of the gear ring and the front end cover 103 effectively reduces the assembly space and improves structural sealing and compactness.

[0025] The first-stage planetary transmission 21 includes a first-stage sun gear 211 splined to the front end of the rotor 105, a first-stage planet gear 212 meshing with the first-stage sun gear 211, a first-stage planet carrier 213 mounting the first-stage planet gear 212, and a gear ring 214 meshing with the first-stage planet gear 212 and integrally formed with the front end cover 103. The second-stage planetary transmission 22 includes a second-stage sun gear 221 splined to the first-stage planet carrier 213, a second-stage planet gear 222 meshing with the second-stage sun gear 221, and a second-stage planet carrier 223 mounting the second-stage planet gear 222. The gear ring 214 meshes with the second-stage planet gear 222, and the hub 3 is coaxially fixed with the second-stage planet carrier 223. The front end of the rotor 105 is splined to the first-stage sun gear 211, so that the first-stage sun gear 211 has a certain amount of radial floating when it is running. The second-stage sun gear 221 is splined to the first-stage planetary carrier 213, so that the second-stage sun gear 221 has a certain amount of radial floating when it is running. This can reduce the noise of the planetary gear set due to uneven load and manufacturing errors, and at the same time improve the service life of the planetary gear set. After the torque is input to the first-stage sun gear 211, the first-stage sun gear 211 meshes with the first-stage planetary gear 212. The gear ring 214 is fixedly connected to the front end cover 103 on the housing 102. The gear ring 214 is fixed and stationary. The first-stage planetary gear 211 rotates along the gear ring 214, which drives the first-stage planetary carrier 213 to rotate. The first-stage planetary carrier 213 is splinedly connected to the second-stage sun gear 221, which causes the second-stage sun gear 221 to rotate. The second-stage sun gear 221 meshes with the second-stage planetary gear 222. The second-stage planetary gear 222 drives the second-stage planetary carrier 223 to rotate. The second-stage planetary carrier 223 is fixedly connected to the hub 3. The hub is fixedly connected to the rim, thereby realizing the electric wheel assembly driving the whole vehicle.

[0026] The service brake 7 includes a brake disc 71 coaxially fixed to the wheel hub 3, and a hydraulic brake caliper 72 mounted on the front cover 103 and cooperating with the brake disc 71. The hydraulic brake caliper 72 is connected to the vehicle's hydraulic system via an oil pipe. The brake disc 71 rotates synchronously with the wheel hub 3. Under the action of hydraulic pressure, the hydraulic brake caliper 72 clamps the brake disc 71, restricting its rotation and realizing the service braking function. The hydraulic brake caliper 72 is integrated on the front cover 103, with a compact structure, small space occupation, and easy assembly.

[0027] The hydraulic brake caliper 72 includes a brake seat 721 coaxially fixed on the front end cover 103, a piston chamber 722 opened on the front end cover, a brake pad 723 cooperating with the piston chamber 722, a piston chamber 724 opened on the brake seat 721, and a brake pad 725 cooperating with the piston chamber 724. The piston chamber 722 and the piston chamber 724 are respectively connected to the vehicle's hydraulic system through oil pipes. The brake disc 71 is disposed between the brake pad 723 and the brake pad 725. The brake pad 723 moves with the oil intake of the piston chamber 722 and contacts or separates from the brake disc. The brake pad 725 moves with the oil intake of the piston chamber 724 and contacts or separates from the brake disc 71. During braking, brake pad 1 723 and brake pad 2 725 clamp the brake disc 71. When starting the vehicle, brake pad 1 723 and brake pad 2 725 separate from the brake disc 71. Piston chamber 1 722 is opened on the front cover 103. The brake seat 721 is fixed to the front cover 103, so that the hydraulic brake caliper 72 is integrated on the front cover 103. The structure is highly compact, occupies little space, and has higher structural stability and braking reliability.

[0028] The gear ring 214 is coaxially fixed to the rear end of the front end cover 103, and the reducer end cover 8 is coaxially fixed to the front end. The secondary planetary carrier 223 includes a front half carrier 224 fixed to the hub 3 and a rear half carrier 225 fixed behind the front half carrier 224. The reducer end cover 8 is supported on the front half carrier 224 by the front hub bearing 9. The front half carrier 224 and the rear half carrier 225 are respectively supported on the primary planetary carrier 213 by bearings. The gear ring 214 is supported on the rear half carrier by the rear hub bearing 10. The secondary planetary carrier 223 is composed of the front half carrier 224 and the rear half carrier 225, which is a split design, which is beneficial to the operability of processing and assembly. The gear ring 214 has a fixed reducer end cover 8 at the front end. The reducer end cover 8 is supported on the secondary planetary carrier 223 by the front wheel hub bearing 9. The gear ring 214 is supported on the secondary planetary carrier 223 by the rear wheel hub bearing 10. The wheel hub 3 is rotatably connected to the gear ring 214 through the wheel hub bearing to transmit the load. The load is transmitted to the frame through the front cover 103, the housing 102 and the rear cover 101. Its load-bearing capacity meets the requirements of high torque and heavy load.

[0029] The charging / discharging air passage 4 includes a rear cover air passage 41 on the rear cover 101, a housing air passage 42 on the housing 102, a front cover air passage 43 on the front cover 103, a gear ring air passage 44 on the gear ring 214, a reducer end cover air passage 45 on the reducer end cover 8, and a hub air passage 46 on the hub 3. The rear cover air passage 41, housing air passage 42, front cover air passage 43, gear ring air passage 44, and reducer end cover air passage 45 are connected sequentially from back to front. The reducer end cover air passage 45 is connected to the hub air passage 46, and the hub air passage 45 is connected to the air nozzle 5. By utilizing the motor housing, gear ring, reducer end cover, and hub to open the charging / discharging air passage, the charging / discharging air passage 4 is located inside the electric wheel drive assembly, without occupying external space, requiring no additional components, and featuring a simple structure and high integration, meeting the requirements of compact, modular, and lightweight electric wheel drive structures.

[0030] The hub 3 is a cylindrical shape with a rearward opening, and is fitted over the gear ring 214 and the reducer end cover 8. An annular space is formed between the hub 3 and the reducer end cover 8. An air filling and emptying oil seal 11 is provided in the annular space and pressed against the inner wall of the hub 3. The air filling and emptying oil seal 11 has an annular sealing air chamber 111. The reducer end cover air passage 45 is connected to the inner end of the annular sealing air chamber 111, and the hub air passage 45 is connected to the outer end of the annular sealing air chamber 111. Since the hub 3 is a rotating component during operation, while the reducer end cover 8 and gear ring 214 are fixed and stationary components, an annular space is formed between the reducer end cover 8 and the hub 3 to allow gas to flow between the rotating and stationary components. A filling / draining oil seal 11 is press-fitted into the annular space. The filling / draining oil seal 11 has an annular sealing chamber 111 inside. The filling / draining oil seal 11 rotates synchronously with the hub 3. The annular sealing chamber 111 serves as a connecting chamber between the reducer end cover air passage 45 and the hub air passage 46, allowing airflow to flow from the reducer end cover air passage 45 to the hub air passage 46 or from the hub air passage 46 to the reducer end cover air passage 45. This realizes the function of filling gas from the rear end cover air passage 41 to the hub air passage 46 and the function of releasing gas from the hub air passage 46 to the rear end cover air passage 41.

[0031] A method for controlling tire pressure in automobiles employs an electric wheel drive assembly with an integrated inflation / deflation channel, as described above, to control tire pressure. Its key feature is that the inflation / deflation channel 4 is connected to the vehicle's pneumatic system. Based on real-time tire pressure monitoring data, the pneumatic system controls the inflation / deflation channel to inflate, deflate, or maintain tire pressure during vehicle operation. This method involves forming an inflation / deflation channel 4 from rear to front within the electric wheel drive assembly, connecting the inflation / deflation channel 4 to the vehicle's pneumatic system, and controlling the inflation / deflation channel to inflate, deflate, or maintain tire pressure during vehicle operation based on real-time tire pressure monitoring data, thus achieving automatic tire inflation / deflation during vehicle movement.

[0032] The technical solutions of the embodiments of the present invention have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. An integrated motorized wheel drive assembly with a self-inflating and deflating air channel, comprising a wheel hub motor, a planetary reducer in driving connection with the wheel hub motor, and a wheel hub fixed with an output end of the planetary reducer, characterized in that An air inlet / outlet channel is provided on the hub motor. The air inlet / outlet channel extends forward through the planetary reducer to the hub and connects with the tire valve on the hub. A parking brake is installed at the rear end of the hub motor for braking protection when the vehicle is parked, and a service brake is installed at the front end for braking when the vehicle is in motion. The hub motor includes a rear end cover connected to the vehicle frame, a housing coaxially fixed to the rear end cover, a front end cover coaxially fixed to the housing, a stator coaxially fixed in the housing, and a rotor cooperating with the stator. The rear end of the rotor is supported by the rear end cover, and the front end is supported by the front end cover. The parking brake is a disc electronic parking brake. The rear end of the rotor extends out of the rear end cover and is splinedly connected to the parking brake. The planetary reducer includes a first-stage planetary drive splined to the front end of the rotor and a second-stage planetary drive splined to the first-stage planetary drive. The first-stage planetary drive and the second-stage planetary drive share a gear ring, which is integrally formed with the front end cover. The hub is fixed to the planet carrier in the second-stage planetary drive. The first-stage planetary transmission includes a first-stage sun gear connected to the front end of the rotor by a spline, a first-stage planet gear meshing with the first-stage sun gear, a first-stage planet carrier equipped with the first-stage planet gear, and a gear ring meshing with the first-stage planet gear and integrally formed with the front end cover. The second-stage planetary transmission includes a second-stage sun gear connected to the first-stage planet carrier by a spline, a second-stage planet gear meshing with the second-stage sun gear, and a second-stage planet carrier equipped with the second-stage planet gear. The gear ring meshes with the second-stage planet gear, and the hub is coaxially fixed with the second-stage planet carrier. The rear end of the gear ring is coaxially fixed to the front end cover, and the front end is coaxially fixed to the reducer end cover. The secondary planetary carrier includes a front half carrier fixed to the hub and a rear half carrier fixed behind the front half carrier. The reducer end cover is supported on the front half carrier by the front hub bearing. The front half carrier and the rear half carrier are respectively supported on the primary planetary carrier by bearings. The gear ring is supported on the rear half carrier by the rear hub bearing. The charging and discharging air passages include the rear cover air passage on the rear cover, the housing air passage on the housing, the front cover air passage on the front cover, the gear ring air passage on the gear ring, the reducer end cover air passage on the reducer end cover, and the wheel hub air passage on the wheel hub. The rear cover air passage, housing air passage, front cover air passage, gear ring air passage, and reducer end cover air passage are connected sequentially from back to front. The reducer end cover air passage is connected to the wheel hub air passage, and the wheel hub air passage is connected to the air nozzle.

2. The electric wheel drive assembly with integrated charging and discharging air passages according to claim 1, characterized in that: The service brake includes a brake disc fixed coaxially with the wheel hub, and a hydraulic brake caliper mounted on the front cover and cooperating with the brake disc. The hydraulic brake caliper is connected to the vehicle's hydraulic system via an oil pipe.

3. The electric wheel drive assembly with integrated charging and discharging air passages according to claim 2, characterized in that: The hydraulic brake caliper includes a brake seat coaxially fixed on the front cover, a piston chamber 1 opened on the front cover, a brake pad 1 that mates with the piston chamber 1, a piston chamber 2 opened on the brake seat, and a brake pad 2 that mates with the piston chamber 2. The piston chamber 1 and piston chamber 2 are respectively connected to the vehicle's hydraulic system through oil pipes. The brake disc is disposed between the brake pad 1 and brake pad 2. The brake pad 1 moves and contacts or separates from the brake disc as oil enters the piston chamber 1, and the brake pad 2 moves and contacts or separates from the brake disc as oil enters the piston chamber 2.

4. The electric wheel drive assembly with integrated charging and discharging air passages according to claim 1, characterized in that: The hub is a cylindrical shape with a rearward opening, which is fitted over the gear ring and the reducer end cover. An annular space is formed between the hub and the reducer end cover. A filling and releasing oil seal is installed in the annular space and pressed against the inner wall of the hub. The filling and releasing oil seal has an annular sealing air chamber. The air passage of the reducer end cover is connected to the inner end of the annular sealing air chamber, and the air passage of the hub is connected to the outer end of the annular sealing air chamber.

5. A method for controlling tire pressure in automobiles, comprising using an electric wheel drive assembly with an integrated inflation / deflation passage as described in any one of claims 1 to 4 to control tire pressure, characterized in that: The air inlet / outlet channels are connected to the vehicle's pneumatic system. Based on real-time tire pressure monitoring data, the air inlet / outlet channels are controlled by the pneumatic system to inflate, deflate, or maintain tire pressure while the vehicle is in motion.

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