Speed reduction hub electric wheel system with lightweight cooling and supporting structure

Abstract

The invention relates to a speed reduction hub electric wheel system with a lightweight cooling and supporting structure, which comprises hub electric wheel bodies arranged at two ends of an axle, the hub electric wheel bodies are assembled and fixed on a frame body, the frame body is provided with a lightweight oil cooling unit, the lightweight oil cooling unit is integrally mounted on a battery pack shell, and the lightweight oil cooling unit is connected with the battery pack shell. An EPB actuator is further integrally installed on the battery pack shell, the light-weight oil cooling unit communicates with the interior of the hub electric wheel body through a long pipeline, the light-weight oil cooling unit comprises an oil cooler, an oil pump and a filter, and a motor, a speed reducer, a rotor supporting bearing, a hub bearing and a brake are integrally installed on the hub electric wheel body. And the motor, the speed reducer and the rotor supporting bearing adopt an integrated oil cooling design. Compared with the prior art, the internal space and a cooling system of the electric wheel can be optimized, the unsprung mass is reduced, and the overall reliability of the electric wheel is improved.

Description

Technical Field

[0001] This invention relates to the field of hub electric drive assembly technology, and in particular to a deceleration hub electric wheel system with a lightweight cooling and support structure. Background Technology

[0002] Compared to traditional gasoline vehicles, electric vehicles can achieve energy conservation and emission reduction by using electricity instead of fuel. Electric vehicles can be divided into centralized drive and distributed drive according to their drive method. Among them, the drive shaft, transfer case and differential of the centralized drive occupy most of the space of the vehicle's longitudinal beam, affecting the overall layout and weight reduction of the vehicle, and the overall efficiency of the multi-link drive chain is low. Distributed drive has the advantages of short drive chain, low loss and high efficiency, independent control of each wheel and good road adaptability, and is the current hot topic of electric vehicle design development and drive control research.

[0003] For distributed drive vehicles, in-wheel electric wheels, primarily driven by in-wheel motors, significantly simplify the chassis structure and allow for flexible placement of components other than the drive system. These include both direct-drive and geared-drive in-wheel electric wheel solutions. Compared to geared-drive in-wheel electric wheels, direct-drive in-wheel electric wheels offer higher efficiency and a simpler structure, providing faster acceleration and a better driving experience. However, their disadvantages include the need for higher motor power, more complex control systems, and higher manufacturing and maintenance costs. Currently, direct-drive in-wheel electric wheels are mainly used in high-performance electric vehicles and racing cars. Geared-drive in-wheel electric wheels, on the other hand, integrate an electric motor and a reducer inside the wheel. This technology has been widely used in electric bicycles and electric motorcycles, offering advantages such as improved system efficiency and driving comfort. However, the design of hub-mounted electric wheels is quite challenging. Improper arrangement of the motor and reduction mechanism within the electric wheel can lead to unreasonable placement of the wheel's main bearing, excessive space occupied by the hub motor on the outer side of the wheel, insufficient space for the steering kingpin, suspension, and braking system, and unreasonable load-bearing of components such as the motor housing. If the braking system is not properly arranged, it will affect the reliability and safety of the electric wheel, and the heat generated by the braking system will affect the motor's performance. In addition, hub-mounted electric wheels also face the problem of excessive unsprung mass, resulting in poor overall vehicle ride comfort. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a deceleration hub electric wheel system with a lightweight cooling and support structure, which can optimize the internal space and cooling system of the electric wheel, reduce unsprung mass, and improve the overall reliability of the electric wheel.

[0005] The objective of this invention can be achieved through the following technical solution: a deceleration hub electric wheel system with a lightweight cooling and support structure, comprising hub electric wheel bodies disposed at both ends of the axle, the hub electric wheel bodies being assembled and fixed to the vehicle frame body, a lightweight oil cooling unit being disposed on the vehicle frame body, the lightweight oil cooling unit being integrated and installed on the battery pack housing, the lightweight oil cooling unit being connected to the interior of the hub electric wheel body, and a motor, a reducer, a rotor support bearing, a hub bearing, and a brake being integrated and installed on the hub electric wheel body, wherein the motor, reducer, and rotor support bearing adopt an integrated oil cooling design.

[0006] Furthermore, the lightweight oil cooling unit includes an oil cooler, a filter, and an oil pump. The oil cooler, filter, oil pump, and hub electric wheel body are connected by pipes. Coolant flows through the pipes, which are arranged along the vehicle frame. The pipes connected to the hub electric wheel body are flexible hoses to accommodate tire bounce.

[0007] Furthermore, the oil cooler, filter, oil pump, and hub electric wheel body are all provided with oil inlet and oil outlet. The coolant flows out from the oil outlet of the hub electric wheel body and flows into the filter from the oil inlet through the pipeline. Coolant flows out from the oil outlet of the filter and flows in through the pipeline from the oil inlet of the oil pump; Coolant flows out from the oil pump outlet and into the oil cooler through the pipeline; Coolant flows out from the oil cooler's outlet, then flows into the inlet of the wheel hub electric wheel body on the front and rear axles through pipes. After cooling the inside of the wheel hub electric wheel body, it flows out through the outlet again to start the next cooling cycle.

[0008] Furthermore, the hub electric wheel body has three interconnected sub-cavities inside, which are used to install the motor, reducer and rotor support bearing respectively.

[0009] Furthermore, the hub electric wheel body includes a housing unit for dividing the interior of the hub electric wheel body into three sub-cavities. The housing unit includes an electric wheel housing, an electric wheel end cover, a bearing end cover, and a hub bearing seat. The electric wheel housing is machined with oil passages and nozzles, and the electric wheel end cover is machined with oil grooves and oil passages.

[0010] Furthermore, the hub bearing is a third-generation tapered roller hub bearing, the outer ring of the hub bearing and the hub bearing housing are integrated into one design, and half of the inner ring of the hub bearing is integrated into the axle.

[0011] Furthermore, rollers are installed between the outer and inner rings of the hub bearing, and a sealing ring, a sealing gasket, and a retaining ring are installed at the end of the hub bearing.

[0012] Furthermore, the reducer is a planetary gear reducer, which consists of a sun gear, planet gears, a planet carrier, and a gear ring. The gear ring is fixedly connected to the housing unit, and the planetary gear reducer is nested inside the motor.

[0013] Furthermore, the brake is a drum brake, and the brake base plate of the drum brake is integrated and installed on the hub electric wheel body.

[0014] Furthermore, an EPB (Electrical Park Brake) actuator is integrated and installed on the battery pack housing. The EPB actuator extends along the wheel hub electric wheel body through a long parking cable and is connected to the brake base plate and the brake parking rocker arm.

[0015] Compared with the prior art, the present invention has the following advantages: This invention assembles and fixes the hub-mounted electric wheel body to the vehicle frame body, and installs a lightweight oil-cooling unit on the vehicle frame body. This lightweight oil-cooling unit is integrated into the battery pack housing and is connected to the interior of the hub-mounted electric wheel body. Furthermore, the hub-mounted electric wheel body integrates a motor, reducer, rotor support bearing, hub bearing, and brake. The motor, reducer, and rotor support bearing employ an integrated oil-cooling design. This achieves integrated and lightweight design of the electric wheel's internal space and cooling unit, reducing the overall unsprung mass of the vehicle and improving the reliability of the electric wheel.

[0016] The lightweight oil cooling unit designed in this invention includes an oil cooler, a filter, and an oil pump. The oil cooler, filter, oil pump, and hub electric wheel body are connected by pipes arranged along the vehicle frame, so that the electric wheels on both sides of the vehicle frame share a set of oil cooling units. Furthermore, the pipes connected to the hub electric wheel body are connected by flexible hoses to accommodate tire bounce, thereby reducing the vibration and impact on the oil cooling unit.

[0017] This invention utilizes a housing unit to divide the interior of the hub electric wheel body into three interconnected sub-cavities for corresponding installation of the motor, reducer, and rotor support bearing. Oil passages and nozzles are machined inside the electric wheel housing of the housing unit, and oil grooves and oil passages are machined inside the electric wheel end cover. This allows the motor, reducer, and rotor support bearing to achieve integrated oil cooling through the cavity oil passage design, which has the advantages of small footprint, low energy consumption, and high cooling efficiency.

[0018] In this invention, the wheel hub bearing adopts a third-generation tapered roller wheel hub bearing. The outer ring of the wheel hub bearing and the wheel hub bearing housing are integrated into one design, and half of the inner ring of the wheel hub bearing is integrated into the wheel axle. This can reduce the space occupied by the wheel hub bearing and reduce the unsprung mass of the whole vehicle.

[0019] In this invention, the brake is a drum brake, in which the brake base plate is integrated and installed on the hub electric wheel body. In addition, an EPB actuator is integrated and installed on the battery pack housing. The EPB actuator extends along the hub electric wheel body through the long parking cable and into the brake base plate to connect with the brake parking rocker arm, which can further reduce the unsprung mass and improve the braking reliability of the electric wheel. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is an internal cross-sectional view of the hub-driven electric wheel body in this invention; Figure 3 This is a schematic diagram of the hub bearing structure in this invention; Figure 4 This is a schematic diagram showing the installation position of the EPB actuator in this invention; The markings in the diagram are as follows: 1. Hub electric wheel body; 2. Oil cooler; 3. Filter; 4. Oil pump; 5. Battery pack housing; 6. EPB actuator; 101. Motor; 102. Reducer; 103. Rotor support bearing; 104. Hub bearing; 105. Brake; 10401. Inner ring of hub bearing; 10402. Outer ring of hub bearing; 10403. Roller; 10404. Sealing ring; 10405. Sealing gasket; 10406. Retaining ring. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Example To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of the present invention, not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can be arranged and designed in various different configurations. Reference is made below. Figures 1-4 A deceleration hub electric wheel according to an embodiment of the present invention is described.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] like Figure 1As shown, a lightweight cooling and support structure for a deceleration hub electric wheel system includes a lightweight oil-cooling unit mounted on the vehicle frame and hub electric wheel bodies 1 mounted at both ends of the axle. The hub electric wheel bodies 1 are also mounted and fixed to the vehicle frame, and the electric wheels on both sides of the rear axle share a common oil-cooling system. The lightweight oil-cooling unit includes an oil cooler 2, a filter 3, and an oil pump 4, all of which are integrated into the battery pack housing 5. In addition, the battery pack housing 5 also integrates an EPB actuator 6.

[0025] The hub electric wheel body 1, oil cooler 2, filter 3, and oil pump 4 are connected by a long pipe. The pipe is arranged along the frame and fixed to the frame by fastening components. Coolant flows in the pipe, and the wheel end cooling pipe connected to the hub electric wheel body 1 is a flexible hose, which can suppress the unsprung mass of the vehicle and adapt to tire bounce, so that the coolant is less affected by vibration and impact during circulation and has high reliability.

[0026] The hub electric wheel 1, oil cooler 2, filter 3, and oil pump 4 are all equipped with corresponding oil inlets and outlets. The electric wheel pipeline interface is opened on the housing of the hub electric wheel body 1. A cooling oil channel is formed inside the housing through perforation and sealing rings. The coolant flows out from the oil outlet of the hub electric wheel body 1 and flows into the filter 3 through the oil inlet via the pipeline. The coolant flows out from the oil outlet of the filter 3 and flows into the oil pump 4 through the pipeline. The coolant flows out from the oil pump 4 and flows into the oil cooler 2 through the pipeline. The coolant flows out from the oil cooler 2 and flows into the front and rear axle hub electric wheel body 1 through the pipeline. After cooling the inside of the hub electric wheel body 1, it flows out through the oil outlet for the next cycle.

[0027] In this embodiment, the oil pump 4 is a low-integration oil pump with high pressure and high flow rate.

[0028] like Figure 2As shown, a motor 101, a reducer 102, a rotor support bearing 103, a hub bearing 104, and a brake 105 are integrated and installed inside the hub electric wheel body 1. The motor 101, the reducer 102, and the rotor support bearing 103 adopt an integrated oil-cooling design. The hub electric wheel body 1 includes a housing unit, which comprises an electric wheel housing, an electric wheel end cover, a bearing end cover, and a hub bearing seat. The housing unit divides the interior of the hub electric wheel body 1 into three sub-cavities: a motor sub-cavity, a reducer sub-cavity, and a rotor support bearing sub-cavity. These three sub-cavities are interconnected to achieve integrated oil cooling, allowing the coolant to simultaneously cool the motor 101, reducer 102, and rotor support bearing 103, resulting in better cooling performance. The electric wheel housing has oil channels and nozzles machined within it. The oil channels are connected to the nozzles and the oil pump outlet, with the nozzles aligned with the stator windings of the motor 101. The electric wheel end cover has oil grooves and oil channels. The oil grooves collect the coolant from the motor sub-cavity, while the oil channels guide the collected coolant to the reducer sub-cavity. The hub bearing seat is fixed to the electric wheel end cover with screws to transfer the load on the hub bearing 104 to the electric wheel end cover.

[0029] In this embodiment, the motor 101 is an internal rotor permanent magnet synchronous motor, consisting of a stator and a rotor. The stator is fixedly connected to the motor wheel housing, and the rotor is fixedly connected to the rotor support. The reducer 102 is a planetary gear reducer, consisting of a sun gear, planet gears, a planet carrier, and a gear ring. The sun gear and the sun gear shaft are integrated. The sun gear (shaft) is installed in the center hole of the rotor support of the motor 101 and is fixedly connected to the rotor support. The gear ring is fixedly connected to the housing unit. The planetary gear reducer is nested inside the motor 101.

[0030] In this embodiment, the rotor support bearing 103 is a deep groove ball bearing and a needle roller bearing (using oil bath lubrication), which together support the motor rotating system composed of the rotor, rotor support and sun gear of the motor 101; wherein, the deep groove ball bearing is installed in the housing of the motor 101, and its inner and outer rings are completely positioned to fix the axial position of the motor rotating system relative to the housing unit; the needle roller bearing is arranged between the planet carrier and the sun gear, and its axial direction is completely floating to enhance the structural rigidity of the motor rotating system.

[0031] The hub bearing 104 (grease-lubricated) is fixedly connected to the housing unit, supporting the wheel rotation system composed of the wheel rim, brake drum, and axle. Figure 3As shown, in this embodiment, the wheel hub bearing 104 is a third-generation tapered roller wheel hub bearing. The outer ring 10402 of the wheel hub bearing is integrated with the wheel hub bearing housing. Half of the inner ring 10401 of the wheel hub bearing is integrated with the wheel axle, thereby reducing the number of electric wheel structural components and suppressing the unsprung mass of the vehicle. A roller 10403 is installed between the outer ring 10402 and the inner ring 10401 of the wheel hub bearing. A sealing ring 10404, a sealing gasket 10405, and a retaining ring 10406 ​​are installed at the end of the wheel hub bearing 104.

[0032] In this embodiment, the brake 105 is a low-speed, long-life drum brake, integrated into the motor housing end cover, with the brake base plate integrated with the electric wheel housing. The brake shoes of the drum brake integrate the friction pads of the parking rocker arm, forming a friction pair with the low-speed, large-radius brake drum, resulting in high braking efficiency and long service life. Figure 4 As shown, the EPB actuator 6, which is integrated and installed on the battery pack housing 5, will be connected to the brake parking rocker arm by extending along the electric wheel housing into the brake base plate via a long parking cable, in order to adapt to tire bounce, reduce unsprung mass, and enhance reliability.

[0033] Applying this solution to practical applications can realize a lightweight, low unsprung mass, highly reliable, and impact-resistant deceleration hub electric wheel, which will help promote the development of hub electric wheel assemblies and their application in commercial vehicles and passenger vehicles.

Claims

1. A deceleration hub electric wheel system with a lightweight cooling and support structure, characterized in that, The vehicle includes hub electric wheel bodies (1) located at both ends of the axle. The hub electric wheel bodies (1) are mounted and fixed to the vehicle frame body. The vehicle frame body is equipped with a lightweight oil cooling unit. The lightweight oil cooling unit is integrated and installed on the battery pack housing (5). The lightweight oil cooling unit is connected to the interior of the hub electric wheel bodies (1). The hub electric wheel bodies (1) are integrated and installed with a motor (101), a reducer (102), a rotor support bearing (103), a hub bearing (104), and a brake (105). The motor (101), the reducer (102), and the rotor support bearing (103) adopt an integrated oil cooling design.

2. The reduction hub electric wheel system with lightweight cooling and support structure according to claim 1, characterized in that, The lightweight oil cooling unit includes an oil cooler (2), a filter (3) and an oil pump (4). The oil cooler (2), the filter (3), the oil pump (4) and the hub electric wheel body (1) are connected by a pipe. Coolant flows in the pipe. The pipe is arranged along the vehicle frame. The pipe connected to the hub electric wheel body (1) is a flexible hose to accommodate tire bounce.

3. The reduction hub electric wheel system with lightweight cooling and support structure according to claim 2, characterized in that, The oil cooler (2), filter (3), oil pump (4) and hub electric wheel body (1) are all provided with oil inlet and oil outlet. The coolant flows out from the oil outlet of the hub electric wheel body (1) and flows into the filter (3) through the oil inlet of the filter (3) via the pipeline. Coolant flows out from the oil outlet of the filter (3) and flows in through the pipeline from the oil inlet of the oil pump (4); Coolant flows out from the oil outlet of the oil pump (4) and flows in through the pipeline from the oil inlet of the oil cooler (2); Coolant flows out from the oil outlet of the oil cooler (2), flows into the oil inlet of the hub electric wheel body (1) of the front and rear axles through the pipeline, cools the inside of the hub electric wheel body (1), and then flows out through the oil outlet to carry out the next cooling cycle.

4. The reduction hub electric wheel system with lightweight cooling and support structure according to claim 1, characterized in that, The hub electric wheel body (1) has three interconnected sub-cavities inside, which are used to install the motor (101), reducer (102) and rotor support bearing (103).

5. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 4, characterized in that, The hub electric wheel body (1) includes a housing unit for dividing the interior of the hub electric wheel body (1) into three sub-cavities. The housing unit includes an electric wheel housing, an electric wheel end cover, a bearing end cover, and a hub bearing seat. The electric wheel housing is machined with oil passages and nozzles, and the electric wheel end cover is machined with oil grooves and oil passages.

6. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 5, characterized in that, The hub bearing (104) is a third-generation tapered roller hub bearing. The outer ring of the hub bearing (104) and the hub bearing housing are integrated. Half of the inner ring of the hub bearing (104) is integrated with the axle.

7. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 6, characterized in that, Rollers are installed between the outer and inner rings of the hub bearing (104), and a sealing ring, a sealing gasket, and a retaining ring are installed at the end of the hub bearing (104).

8. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 5, characterized in that, The reducer (102) is a planetary gear reducer (102), which consists of a sun gear, planet gears, a planet carrier and a gear ring. The gear ring is fixedly connected to the housing unit. The planetary gear reducer (102) is nested inside the motor (101).

9. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 1, characterized in that, The brake (105) is a drum brake, and the brake base plate of the drum brake is integrated and installed on the hub electric wheel body (1).

10. A reduction hub electric wheel system with a lightweight cooling and support structure according to claim 9, characterized in that, An EPB actuator (6) is integrated and installed on the battery pack housing (5). The EPB actuator (6) extends into the brake base plate and is connected to the brake parking rocker arm via a long parking cable along the wheel hub electric wheel body (1).

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