Double-motor two-stage transmission electric drive axle

Abstract

The invention discloses a dual-motor two-stage transmission electric drive axle, and belongs to the technical field of new energy automobile electric drive. The drive axle solves the technical problems of insufficient power and transmission efficiency attenuation of a commercial vehicle under complex working conditions through the innovative combination of dual-motor cooperative driving and a two-stage transmission structure. The first driving motor and the second driving motor are axially arranged in parallel, output gears of the first driving motor and the second driving motor are meshed with an input gear of an intermediate shaft to form two-stage speed reduction transmission, and a differential receives power through an output gear of the intermediate shaft. The hollow shaft design enables the left half shaft to penetrate through the rotor shaft of the first driving motor, coaxial layout of the differential mechanism and the motor is achieved, the transmission stage number is reduced compared with a traditional three-stage speed reduction system, and mechanical efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of dual-motor electric drive axles, and in particular to a dual-motor two-stage transmission electric drive axle. Background Art

[0002] As a means of production, the economic efficiency of commercial vehicles throughout their life cycle has become a core concern for users. With the advancement of three-electric technology and the emergence of operating cost advantages, new energy commercial vehicles are accelerating their penetration from urban logistics scenarios to inter-city and urban-rural logistics scenarios. It is worth noting that inter-city and urban-rural logistics transportation generally face more complex working conditions, especially full-load starting, mountain climbing and other scenarios that put higher requirements on the continuous torque output of the drive system. The traditional single-motor electric drive system can no longer meet the actual operational needs.

[0003] In response to the above technical pain points, existing technologies such as CN114771228A proposed a dual-motor three-stage transmission electric drive axle solution, which improves the system power density by arranging dual power sources in parallel. However, in-depth research shows that this solution has significant technical bottlenecks: First, although the three-stage reduction structure can amplify the torque, as the total reduction ratio increases, the mechanical transmission efficiency decreases nonlinearly, which directly affects the vehicle's cruising range; secondly, the dual-motor double-sided arrangement mode leads to an increase in the volume of the electric drive axle, which conflicts with the compact design trend of commercial vehicle chassis. How to achieve an optimal balance between transmission efficiency and spatial layout while ensuring power performance has become a key technical problem that needs to be solved in the electric drive system of new energy commercial vehicles. Summary of the invention

[0004] The purpose of the present invention is to address the corresponding deficiencies in the prior art and provide a dual-motor two-stage transmission electric drive axle. The dual-motor two-stage transmission electric drive axle is configured with a first drive motor and a second drive motor. The first drive motor and the second drive motor mesh with the intermediate shaft input gear on the intermediate shaft to transmit power. The rotor shaft of the first drive motor is a hollow shaft, and the left half shaft passes through the rotor shaft and is connected to the differential, thereby achieving efficient transmission and compact layout.

[0005] The objective of the present invention is achieved by adopting the following scheme: A dual-motor two-stage transmission electric drive axle, comprising an electric drive axle housing, wherein a reducer gear set and a differential are supported in the electric drive axle housing, and a first drive motor and a second drive motor are also supported in the electric drive axle housing, which are axially parallel and arranged in parallel; The reducer gear set is a two-stage transmission gear set, including an intermediate shaft, an intermediate shaft input gear on the intermediate shaft meshes with a first output gear of the first drive motor and a second output gear of the second drive motor, and an intermediate shaft output gear on the intermediate shaft meshes with a differential input gear to transmit power; The first driving motor and the differential are coaxially arranged. The motor shaft of the first driving motor is a hollow shaft. One end of the left half shaft passes through the inner hole of the motor shaft of the first driving motor and is connected to the left half shaft bevel gear of the differential, and the other end extends out of the electric drive axle housing and is connected to the left wheel hub. One end of the right half shaft is connected to the right half shaft bevel gear of the differential, and the other end extends out of the electric drive axle housing and is connected to the right wheel hub.

[0006] Preferably, both the first driving motor and the second driving motor include a motor stator and a motor rotor. The motor rotor is located inside the motor stator. The first output gear of the first driving motor is located on the rotor shaft of the first driving motor, and the second output gear of the second driving motor is located on the rotor shaft of the second driving motor.

[0007] Preferably, a first driving motor installation cavity and a second driving motor installation cavity are provided inside the electric drive axle housing, and the first driving motor installation cavity and the second driving motor installation cavity are separated by a cavity wall.

[0008] Preferably, half shaft installation cavities extending outward are respectively provided on both sides of the electric drive axle housing. The left half shaft extends out of the left half shaft installation cavity and is connected to the left wheel hub, and the right half shaft extends out of the right half shaft installation cavity and is connected to the right wheel hub.

[0009] Preferably, the rotor shafts of the first driving motor, the rotor shaft of the second driving motor, the intermediate shaft, and the differential are respectively supported in the electric drive axle housing by bearings.

[0010] The beneficial effects of the present invention are as follows: Good power performance and high transmission efficiency: Through the design of dual-motor coordinated drive and two-stage transmission structure, the co-engagement layout of the intermediate shaft input gear and the dual-motor output gears realizes two-stage deceleration. The dual-motor coordinated drive effectively solves the problem of insufficient power under the full-load climbing condition of commercial vehicles. The two-stage deceleration has higher mechanical transmission efficiency than the three-stage deceleration, which can significantly extend the vehicle's cruising range. Moreover, the single-motor drive or dual-motor drive mode can be flexibly switched according to the working conditions. For example, the single motor operates during high-speed cruising, and the dual motors output during climbing, realizing the efficient utilization of electric energy.

[0011] Innovative space layout: Through the hollow shaft design of the first driving motor, the left half shaft and the motor rotor form a coaxial layout. This structure meets the requirements of compactification of commercial vehicle chassis, reduces the volume of the drive system, and provides more space for systems such as battery packs. The electric drive axle housing adopts a split cavity design to isolate the dual-motor installation cavities, effectively improving the NVH performance of the system.

[0012] Improved reliability: With the dual-motor design, when one motor fails, the remaining motor can still maintain the basic driving ability of the vehicle through two-stage transmission, ensuring the emergency driving ability of the vehicle and significantly improving the operation safety of commercial vehicles.

[0013] In summary, this technology improves power performance and transmission efficiency through the coordinated drive of dual motors and a two-stage transmission structure, solves the problem of insufficient power for commercial vehicles when fully loaded and climbing slopes, and extends the endurance with a single / double motor intelligent switching mode (such as single drive at high speed and dual drive when climbing slopes); innovatively adopts a coaxial layout of hollow shafts and a split-chamber electric drive axle housing design to achieve compact space optimization and NVH performance improvement; the dual-motor redundancy system can maintain emergency driving ability in case of a single-motor failure, significantly improving the operational safety and reliability of commercial vehicles. Brief Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of the present invention. Detailed Embodiments

[0015] As Figure 1 shown, a dual-motor two-stage transmission electric drive axle includes an integrally formed electric drive axle housing 1. The electric drive axle housing 1 includes a first drive motor installation cavity 20, a second drive motor installation cavity 21, a differential and a reduction gear set installation cavity, and half-axle installation cavities 16 extending outward on both sides. The first drive motor installation cavity 20, the second drive motor installation cavity 21, and the differential and reduction gear set installation cavity are separated by cavity walls 22. A first drive motor 3 is supported in the first drive motor installation cavity 20, and a second drive motor 4 is supported in the second drive motor installation cavity 21. The first drive motor 3 and the second drive motor 4 are arranged in parallel axially. A reduction gear set and a differential 2 are supported in the differential and reduction gear set installation cavity.

[0016] The reduction gear set is a two-stage transmission gear set, including an intermediate shaft 5. An intermediate shaft input gear 6 fixedly arranged on the intermediate shaft 5 meshes with a first output gear 7 of the first drive motor 3 and a second output gear 8 of the second drive motor 4. That is, the intermediate shaft input gear 6 meshes with the first output gear 7 and the second output gear 8 at the same time. An intermediate shaft output gear 9 fixedly arranged on the intermediate shaft 5 meshes with a differential input gear 10 to transmit power. The power is generated separately or jointly by the first drive motor 3 and / or the second drive motor 4, and is transmitted to the differential 2 through the reduction gear set and then to the half-axle.

[0017] The first drive motor 3 and the second drive motor 4 both include a motor stator 18 and a motor rotor 19. The motor rotor 19 is located inside the motor stator 18. The first output gear 7 of the first drive motor 3 is located on the rotor shaft of the first drive motor 3, and the second output gear 8 of the second drive motor 4 is located on the rotor shaft of the second drive motor 4. The rotor shafts of the first drive motor 3, the second drive motor 4, the intermediate shaft 5, and the differential 2 are respectively supported in the electric drive axle housing 1 through bearings.

[0018] The first driving motor 3, the differential 2, and the half-shaft mounting cavity 16 are coaxially arranged. The motor shaft of the first driving motor 3 is a hollow shaft 11. One end of the left half-shaft 12 passes through the inner hole of the motor shaft of the first driving motor 3 and is connected to the left half-shaft bevel gear of the differential 2, and the other end extends out of the electric drive axle housing 1 and is connected to the left wheel hub 14. One end of the right half-shaft 15 is connected to the right half-shaft bevel gear of the differential 2, and the other end extends out of the electric drive axle housing 1 and is connected to the right wheel hub 17. The left half-shaft 12 extends out of the left half-shaft mounting cavity 16 and is connected to the left wheel hub 14, and the right half-shaft 15 extends out of the right half-shaft mounting cavity 16 and is connected to the right wheel hub 17.

[0019] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications made by those skilled in the art without departing from the spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A dual-motor two-stage transmission electric drive axle, comprising an electric drive axle housing (1), wherein a reducer gear set and a differential (2) are supported in the electric drive axle housing (1), characterized in that: The electric drive axle housing (1) also supports a first drive motor (3) and a second drive motor (4) which are axially parallel and arranged side by side. The reducer gear set is a two-stage transmission gear set, comprising an intermediate shaft (5), an intermediate shaft input gear (6) on the intermediate shaft (5) meshing with a first output gear (7) of a first drive motor (3) and a second output gear (8) of a second drive motor (4), and an intermediate shaft output gear (9) on the intermediate shaft (5) meshing with a differential input gear (10) to transmit power; The first drive motor (3) and the differential (2) are coaxially arranged, the motor shaft of the first drive motor (3) is a hollow shaft (11), one end of the left half shaft (12) passes through the inner hole of the motor shaft of the first drive motor (3) and is connected to the left half shaft bevel gear of the differential (2), and the other end extends out of the electric drive axle housing (1) and is connected to the left wheel hub (14), and one end of the right half shaft (15) is connected to the right half shaft bevel gear of the differential (2), and the other end extends out of the electric drive axle housing (1) and is connected to the right wheel hub (17).

2. The dual-motor two-stage transmission electric drive axle according to claim 1, characterized in that: The first drive motor (3) and the second drive motor (4) both comprise a motor stator (18) and a motor rotor (19); the motor rotor (19) is located inside the motor stator (18); the first output gear (7) of the first drive motor (3) is located on the rotor shaft of the first drive motor (3); and the second output gear (8) of the second drive motor (4) is located on the rotor shaft of the second drive motor (4).

3. The dual-motor two-stage transmission electric drive axle according to claim 1, characterized in that: A first drive motor installation cavity (20) and a second drive motor installation cavity (21) are provided in the electric drive axle housing (1); the first drive motor installation cavity (20) and the second drive motor installation cavity (21) are separated by a cavity wall (22).

4. The dual-motor two-stage transmission electric drive axle according to claim 1, characterized in that: The electric drive axle housing (1) is provided with outwardly extending half-axle installation cavities (16) on both sides, the left half-axle (12) extends out of the left half-axle installation cavity (16) to be connected to the left wheel hub (14), and the right half-axle (15) extends out of the right half-axle installation cavity (16) to be connected to the right wheel hub (17).

5. The dual-motor two-stage transmission electric drive axle according to claim 1, characterized in that: The rotor shaft of the first drive motor (3), the rotor shaft of the second drive motor (4), the intermediate shaft (5), and the differential (2) are supported in the electric drive axle housing (1) via bearings respectively.

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