An electric drive axle assembly

Abstract

The utility model discloses an electric drive axle assembly, including drive motor, differential mechanism, left and right two transmission and left and right two half axle, the rotor of drive motor is integrated with differential mechanism setting, the left and right half axle gear of differential mechanism is fixedly connected with the input shaft of left and right two transmission respectively, and the output shaft of left and right two transmission is correspondingly connected with left and right two half axle respectively, the transmission in the utility model discloses the planetary array transmission or parallel shaft transmission, can reduce differential mechanism load all, realizes the miniaturization of differential mechanism and whole axle weight reduction, and promotes transmission light weight.

Description

Technical Field

[0001] This utility model belongs to the field of electric drive technology for heavy vehicles, specifically relating to an electric drive axle assembly, which is mainly used in the electric drive systems of highway buses, light trucks and other vehicle types. Background Technology

[0002] Electric vehicles, powered by onboard electricity and driven by electric motors, have become an important direction for green development in the transportation sector. In my country's commercial electric vehicle market, electric drive axles are widely used in a significant number of models due to their direct power transmission and high space utilization.

[0003] Currently, most electric drive axle designs adopt a traditional configuration, namely a series structure of "motor + reducer + differential". In this structure, the differential needs to bear all the torque output by the motor to achieve the differential function of the left and right wheels. This results in an extremely high load on the differential, which in turn significantly increases its size and weight, typically accounting for 20%-30% of the total weight of the transmission, seriously affecting the lightweight development of electric drive axles.

[0004] Furthermore, due to the overall structural limitations and assembly process requirements of the electric drive axle assembly, parameters such as motor diameter, differential diameter, and axle housing thickness are mutually constrained, directly affecting the motor offset distance design and transmission speed ratio distribution. To meet assembly feasibility and power transmission reliability requirements, designers have to reserve a large design margin for the transmission, which further increases the overall weight of the transmission. This not only increases the vehicle's curb weight but may also indirectly affect the vehicle's range and power efficiency.

[0005] In summary, existing electric drive axles suffer from technical problems such as high differential load, high weight ratio, and heavy transmission due to limited design margin. A new electric drive axle structure is urgently needed to solve these defects. Summary of the Invention

[0006] To address the technical problems of large differential load and heavy weight in existing electric drive axles, and the difficulty in lightweighting the transmission due to the size limitations of the motor and differential, this utility model proposes an electric drive axle assembly. By optimizing the power transmission sequence and structural integration method, it achieves reduced differential load and smaller size, while reducing the impact of motor and differential size on transmission design, ultimately achieving the goal of overall lightweighting of the electric drive axle.

[0007] The technical solution adopted by this utility model is as follows: an electric drive axle assembly, including a drive motor, a differential, two left and right gearboxes and two left and right half shafts; the rotor of the drive motor is integrated with the differential, the left and right half shaft gears of the differential are respectively fixedly connected to the input shafts of the left and right gearboxes, and the output shafts of the left and right gearboxes are respectively connected to the left and right half shafts for transmission.

[0008] Furthermore, the transmission is a planetary gear transmission, in which the sun gear of the planetary gear transmission is coaxially fixed with the half-shaft gear of the differential, the ring gear of the planetary gear transmission is fixedly installed, and the planet carrier of the planetary gear transmission is drivenly connected to the half-shaft; the rotation axis of the differential is collinear with the rotation axis of the half-shaft.

[0009] Furthermore, the transmission is a parallel shaft transmission, which includes an input gear, an intermediate gear shaft, and an output gear. The input gear is fixedly connected to the half-shaft gear of the differential, the input gear meshes with the intermediate driving gear on the intermediate gear shaft, the intermediate driven gear on the intermediate gear shaft meshes with the output gear, and the output gear is fixedly connected to the half-shaft.

[0010] Furthermore, the housing of the differential is connected to the rotor of the drive motor by a key or welded, and the rotation axis of the differential is collinear with the rotation axis of the drive motor rotor.

[0011] Furthermore, the transmission ratios of the left and right gearboxes are the same to ensure the synchronization of the output speeds of the left and right half-shafts.

[0012] The beneficial effects of this utility model are:

[0013] 1. Reduce differential load, achieving differential miniaturization and overall axle weight reduction: By optimizing the traditional power transmission sequence of "deceleration first, then differential" to "differential first, then deceleration", the differential only needs to bear the initial torque output by the drive motor, without having to bear the torque amplified by the reducer. The load is greatly reduced, which can significantly reduce the size and weight of the differential. At the same time, the integrated design of the drive motor rotor and the differential reduces intermediate transmission components, further reducing the overall weight of the electric drive axle, which is conducive to controlling the vehicle's curb weight and improving its range.

[0014] 2. Reduce size constraints and promote lightweight transmission: Due to the reduced size of the differential and the significant reduction in space constraints on the transmission from the motor and differential after the power transmission sequence is optimized, the transmission design does not need to reserve too much margin. The speed ratio and structure can be flexibly designed according to actual power requirements, effectively reducing the weight of the transmission and further realizing the lightweight design of the electric drive axle. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the first embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of the second embodiment of the present invention;

[0017] In the diagram: 1-Drive motor, 2-Differentiation, 3-Planetary gearbox, 4-Half shaft, 5-Parallel shaft gearbox, 501-Input gear, 502-Intermediate drive gear, 503-Intermediate driven gear, 504-Output gear. Detailed Implementation

[0018] To more clearly illustrate the technical solution of this utility model, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort. To facilitate understanding of this utility model, a more detailed description of this utility model will be provided below in conjunction with the accompanying drawings and specific embodiments.

[0019] The present invention discloses an electric drive axle assembly, including a drive motor 1, a differential 2, two left and right gearboxes connected to the differential 2, and two left and right half shafts 4 connected between the two gearboxes and the wheels on both sides.

[0020] like Figure 1 As shown, the following is the first embodiment of this utility model. In this embodiment, the two transmissions connected to the differential 2 are planetary gearboxes 3. The rotor of the drive motor 1 is integrated with the differential 2, and the power is directly output from the rotor of the drive motor 1 to the differential 2, and the rotation axes of the two are collinear. The left and right half-shaft gears of the differential 2 are respectively fixed coaxially with the sun gears of the left and right planetary gearboxes 3 through splines. The gear ring of the planetary gearbox 3 is fixed to the inner wall of the axle housing. The planet carrier of the planetary gearbox 3 is fixedly connected to the half-shaft 4 through flanges. The drive motor 1, the differential 2 and the planetary gearbox 3 are all fixed in the axle housing with bolts, and the half-shaft 4 passes through the axle housing and extends to the wheel end.

[0021] The power transmission process in this embodiment is as follows: After the drive motor 1 is powered on, the rotor drives the integrated differential 2 to rotate synchronously; the planetary gears in the differential 2 rotate with it, and achieve differential speed by meshing with the left and right half-shaft gears, and transmit power to the sun gear of the left and right planetary gearbox 3; the sun gear drives the planetary gears to rotate around their own axis, and at the same time the planetary gears roll along the inner wall of the gear ring, driving the planet carrier to rotate; the planet carrier transmits power to the half-shaft 4, and finally the half-shaft 4 drives the wheels to rotate.

[0022] In this embodiment, the rotation axes of the rotor of the drive motor 1, the differential 2, the planetary gearbox 3, and the half-shaft 4 are all collinear, which can maximize the reduction of the size and weight of the differential.

[0023] like Figure 2 As shown, the following is the second embodiment of this utility model. In this embodiment, the left and right transmissions connected to the differential 2 are parallel shaft transmissions 5. The rotor of the drive motor 1 is integrated with the differential 2, and the power is directly output from the rotor of the drive motor 1 to the differential 2, and the rotation axes of the two are collinear. The left and right half-shaft gears of the differential 2 are respectively connected and fixed to the input gears 501 of the left and right parallel shaft transmissions 5 by keys. The intermediate gear shaft of the parallel shaft transmission 5 is mounted on the axle housing by bearings. The intermediate gear shaft has an integrally formed intermediate driving gear 502 and intermediate driven gear 503. The intermediate driving gear 502 meshes with the input gear 501, and the intermediate driven gear 503 meshes with the output gear 504. The output gear 504 is fixedly connected to the half-shaft 4 by splines. The drive motor 1, differential 2 and parallel shaft transmission 5 are all fixed in the axle housing by bolts. The half-shaft 4 passes through the axle housing and extends to the wheel end.

[0024] The power transmission process in this embodiment is as follows: After the drive motor 1 is powered on, the rotor drives the integrated differential 2 to rotate synchronously; the differential 2 achieves differential speed through the meshing of planetary gears and left and right half-shaft gears, and transmits power to the input gear 501 of the parallel shaft transmission 5; the input gear 501 drives the intermediate drive gear 502 to rotate, and the intermediate gear shaft rotates synchronously with the intermediate drive gear 502, thereby driving the intermediate driven gear 503 to rotate; the intermediate driven gear 503 drives the output gear 504 to rotate, and the output gear 504 transmits power to the half-shaft 4, ultimately driving the wheels to rotate.

[0025] In the two embodiments described above, the transmission ratios of the left and right gearboxes are the same to ensure synchronized output speeds of the left and right half-shafts 4; the planetary gears of the differential 2 are arranged symmetrically to ensure the smoothness of the differential function. Those skilled in the art can adjust parameters such as the transmission ratio and the number of planetary gears in the differential according to the actual vehicle's power requirements, all of which fall within the protection scope of this utility model.

[0026] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electric drive axle assembly, characterized in that: It includes a drive motor (1), a differential (2), two left and right gearboxes and two left and right half shafts (4); the rotor of the drive motor (1) is integrated with the differential (2), the left and right half shaft gears of the differential (2) are respectively fixedly connected to the input shafts of the left and right gearboxes, and the output shafts of the left and right gearboxes are respectively connected to the left and right half shafts (4) for transmission.

2. The electric drive axle assembly according to claim 1, characterized in that: The transmission is a planetary gearbox (3). The sun gear of the planetary gearbox (3) is coaxially fixed with the half-shaft gear of the differential (2). The ring gear of the planetary gearbox (3) is fixedly installed. The planet carrier of the planetary gearbox is connected to the half-shaft (4) for transmission. The rotation axis of the differential (2) is collinear with the rotation axis of the half-shaft (4).

3. The electric drive axle assembly according to claim 1, characterized in that: The transmission is a parallel shaft transmission (5), which includes an input gear (501), an intermediate gear shaft, and an output gear (504). The input gear (501) is fixedly connected to the half-shaft gear of the differential (2). The input gear (501) meshes with the intermediate driving gear (502) on the intermediate gear shaft. The intermediate driven gear (503) on the intermediate gear shaft meshes with the output gear (504). The output gear (504) is fixedly connected to the half-shaft (4).

4. An electric drive axle assembly according to claim 1, characterized in that: The housing of the differential (2) is connected to the rotor of the drive motor (1) by a key or weld, and the rotation axis of the differential (2) is collinear with the rotation axis of the rotor of the drive motor (1).

5. An electric drive axle assembly according to claim 1, characterized in that: The transmission ratios of the two gearboxes on the left and right sides are the same to ensure the synchronization of the output speeds of the two half-shafts (4).

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