Three-gear electric drive axle

Abstract

The utility model relates to the technical field of electric vehicle driving systems, and discloses a three-gear electric drive axle which comprises a first-stage gear shaft, a second-stage gear shaft and a third-stage gear shaft which are arranged in parallel. The first-stage gear shaft is meshed with the first-stage driven gear; the primary gear shaft is in transmission connection with a driving source; the second-stage gear shaft is meshed with the first-gear driven gear; the second-gear driving gear, the first-stage driven gear and the third-gear driving gear are sequentially arranged on the second-gear gear shaft; the second-gear driving gear is meshed with the second-gear driven gear, and the third-gear driving gear is meshed with the third-gear driven gear; the third-stage gear shaft is meshed with a third-stage driven gear; the first-gear driven gear, the first-gear tooth holder, the second-gear driven gear, the second-gear and third-gear tooth holder and the third-gear driven gear are sequentially arranged on the third-gear shaft. The transmission performance and the structure cost can be both considered, and the purposes of light weight, high performance and long endurance of the whole pure electric heavy truck are achieved in an auxiliary mode.

Description

Technical Field

[0001] The utility model relates to the technical field of electric vehicle drive systems, in particular to a three-speed electric drive axle. Background Art

[0002] In the heavy-duty truck market, pure electric heavy-duty trucks (i.e. heavy-duty trucks powered by electricity) are becoming more and more widely used.

[0003] Currently, pure electric heavy-duty trucks on the market primarily utilize central drive and electric axle drive technologies. The central drive approach allows for rapid initial development and stable vehicle performance. However, due to its larger installation space and the need to transmit power to the axle via a drive shaft, it presents challenges such as high cost, heavy weight, low transmission efficiency, and limited installation space. In contrast, the electric axle drive approaches currently available are primarily two-speed and four-speed electric axles. The wide speed ratio span of the two-speed electric axle limits its practical operating speed to only 60-90 km / h, resulting in low overall efficiency and poor economic performance. While the four-speed electric axle can increase vehicle speeds, it may have certain redundancies, further increasing vehicle cost and weight, placing it at a competitive disadvantage. Therefore, reducing cost and weight while maintaining vehicle performance and improving transmission efficiency are key areas of focus for the current development of pure electric heavy-duty truck technology. Utility Model Content

[0004] The utility model aims to provide a three-speed electric drive axle that can take into account both transmission performance and structural cost, and assist pure electric heavy-duty trucks in achieving the goals of lightweight, high performance and long endurance.

[0005] The basic solution provided by the utility model is: a three-speed electric drive axle, comprising a first-stage gear shaft, a second-stage gear shaft, and a third-stage gear shaft arranged in parallel; and a first-stage driven gear, a first-speed driven gear, a second-speed driving gear, a second-speed driven gear, a third-speed driving gear, a third-speed driven gear, a first-speed gear adapter, and second- and third-speed gear adapters;

[0006] The first-stage gear shaft is meshed with the first-stage driven gear; the first-stage gear shaft is transmission-connected to the driving source; the second-stage gear shaft is meshed with the first-speed driven gear; the second-speed driving gear, the first-stage driven gear and the third-speed driving gear are sequentially arranged on the second-speed gear shaft; the second-speed driving gear is meshed with the second-speed driven gear, and the third-speed driving gear is meshed with the third-speed driven gear;

[0007] The three-stage gear shaft is meshed with the three-stage driven gear; the first-gear driven gear, first-gear gear seat, second-gear driven gear, second- and third-gear gear seats and third-gear driven gear are sequentially arranged on the three-stage gear shaft; the first-gear gear seat is also provided with a first-gear sliding gear sleeve; the second- and third-gear gear seats are also provided with second- and third-gear sliding gear sleeves.

[0008] The working principle and advantages of this utility model are:

[0009] When first gear is engaged, the first gear sliding sleeve moves leftward, connecting it to both the first gear adapter and the first gear driven gear, allowing the first gear driven gear and the third gear shaft to rotate at the same speed. The second and third gear sliding sleeves remain midway between the second and third gear adapters, allowing the second and third gear driven gears to rotate freely. Power is input from the drive source, and the power transmission route is from the first gear shaft to the first gear driven gear, then the second gear shaft, then the first gear driven gear, then the first gear adapter, then the third gear shaft, then the third gear driven gear.

[0010] When second gear is engaged, the second- and third-gear sliding sleeve moves leftward, connecting the second- and third-gear adapters and the second-gear driven gear simultaneously, allowing the second-gear driven gear and the third-stage gear shaft to rotate at the same speed. The first-gear sliding sleeve remains in the center of the first-gear adapter, allowing the first- and third-gear driven gears to rotate freely. Power is input from the drive source, and the power transmission route is from the first-stage gear shaft to the first-stage driven gear, to the second-gear driving gear, to the second-gear driven gear, to the second- and third-gear adapters, to the third-stage gear shaft, and finally to the third-stage driven gear.

[0011] When third gear is engaged, the second- and third-gear sliding sleeve moves to the right, connecting the second- and third-gear adapters and the third-gear driven gear simultaneously, allowing the third-gear driven gear and the third-stage gear shaft to rotate at the same speed. The first-gear sliding sleeve remains in the center of the first-gear adapter, allowing the first- and second-gear driven gears to rotate freely. Power is input from the drive source, and the power transmission route is from the first-stage gear shaft to the first-stage driven gear, to the third-gear driving gear, to the third-gear driven gear, to the second- and third-gear adapters, to the third-stage gear shaft, and finally to the third-stage driven gear.

[0012] In the above process, after the power is output to the three-stage driven gear, the three-stage driven gear outputs the power to the target structure, such as to the differential, and finally transmits it to the left / right half-shaft of the wheel through the differential to provide power to the wheel end.

[0013] The utility model provides a three-speed electric drive axle that can take into account both transmission performance and structural costs, and assist pure electric heavy-duty trucks in achieving the goals of lightweight, high performance, and long driving range. The key point is: this solution provides a new three-speed electric drive axle route. Compared with the two-speed electric drive axle, the gear selection is more flexible and the road adaptability is stronger. The most suitable gear can be selected according to the actual working conditions, taking into account the power performance and economic performance of the vehicle. While the weight and cost are similar, it can achieve stronger power and lower power consumption. Compared with the four-speed electric drive axle, this solution does not have performance redundancy, and is lower in cost and lighter in weight.

[0014] Specifically, this solution utilizes a three-stage reduction transmission with a high overall speed ratio, making it suitable for high-speed, low-torque motors. Compared to low-speed motors, this type of motor offers greater power and density, a smaller footprint, and significant advantages in weight and cost. Furthermore, the motor's high-efficiency range is wider, and combined with this solution's three-speed transmission, it can effectively leverage the high-efficiency advantages of high-speed, low-torque motors, enabling the electric drive axle to maintain high-efficiency operation under various complex operating conditions.

[0015] Second, the structural layout of this solution is simpler and more compact. Compared with the technical solution of arranging the first-stage reduction gear pair separately on one side in the existing electric drive axle structure, this solution arranges the first-stage reduction gear pair of the transmission between the second and third gear pairs, sharing the axial space occupied by the shift structure. This can avoid the first-stage reduction gear pair occupying a section of axial space alone, achieving a shortened overall axial length of the reducer, a more compact structure, and lightweight design and cost reduction. In addition, it is easier to achieve the overall lightweight and compact design of heavy-duty trucks, taking into account system cost and performance, and achieving equivalent performance, lighter weight, smaller dimensions, and lower cost. Third, this solution adopts a parallel shaft helical gear solution, which has smooth overall transmission, high reliability, and good NVH performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural schematic diagram of an embodiment of a three-speed electric drive axle of the utility model. DETAILED DESCRIPTION

[0017] The following is a further detailed description through specific implementation methods:

[0018] The symbols in the drawings of the specification include: drive motor 1, transmission housing 2, first-stage gear shaft 21, second-stage gear shaft 221, second-gear driving gear 222, third-gear driving gear 223, first-stage driven gear 224, first-gear driven gear 231, second-gear driven gear 232, third-gear driven gear 233, third-stage gear shaft 234, first-gear gear seat 235, second- and third-gear gear seats 236, first-gear sliding gear sleeve 237, second- and third-gear sliding gear sleeve 238, third-stage driven gear 241, differential case 242, left half shaft 243, and right half shaft 244.

[0019] The embodiment is basically as shown in the attached Figure 1The figure shows a three-speed electric drive axle, comprising a parallel arrangement of a primary gear shaft 21, a secondary gear shaft 221, and a tertiary gear shaft 234; a primary driven gear 224, a first-gear driven gear 231, a second-gear driving gear 222, a second-gear driven gear 232, a third-gear driving gear 223, a third-gear driven gear 233, a first-gear gear holder 235, and second- and third-gear gear holders 236. The primary gear shaft 21, the secondary gear shaft 221, and the tertiary gear shaft 234 are all disposed within the transmission housing 2. Each end of the primary gear shaft 21, the secondary gear shaft 221, and the tertiary gear shaft 234 is connected to the transmission housing 2 via a bearing.

[0020] The primary gear shaft 21 is meshed with the primary driven gear 224 ; the primary gear shaft 21 is in transmission connection with a driving source; the driving source is a driving motor 1 ; the driving motor 1 is disposed outside the transmission housing 2 .

[0021] The secondary gear shaft 221 is meshed with the first gear driven gear 231; the second gear driving gear 222, the first gear driven gear 224 and the third gear driving gear 223 are sequentially arranged on the second gear gear shaft; the second gear driving gear 222 is meshed with the second gear driven gear 232, and the third gear driving gear 223 is meshed with the third gear driven gear 233.

[0022] The third-stage gear shaft 234 is meshed with the third-stage driven gear 241; the first-gear driven gear 231, the first-gear gear seat 235, the second-gear driven gear 232, the second- and third-gear gear seats 236 and the third-gear driven gear 233 are sequentially arranged on the third-stage gear shaft 234; the first-gear gear seat 235 is also provided with a first-gear sliding gear sleeve 237; the second- and third-gear gear seat 236 is also provided with a second- and third-gear sliding gear sleeve 238.

[0023] The first gear tooth seat 235 and the second and third gear tooth seat 236 are rigidly connected to the third gear shaft 234. The first gear sliding gear sleeve 237 is in sliding cooperation with the first gear tooth seat 235; the second and third gear sliding gear sleeve 238 is in sliding cooperation with the second and third gear tooth seat 236.

[0024] The first gear driven gear 231, the second gear driven gear 232 and the third gear driven gear 233 are loosely mounted on the third gear shaft 234 via a needle bearing. The third gear driven gear 241 is rigidly connected to the differential case 242.

[0025] The differential is respectively connected to the left half shaft 243 and the right half shaft 244 of the vehicle driving wheels.

[0026] In specific applications, the working principle of this three-speed electric drive axle is as follows:

[0027] When first gear is engaged, the first gear sliding sleeve 237 moves leftward, connecting it to both the first gear holder 235 and the first gear driven gear 231, allowing the first gear driven gear 231 and the third gear shaft 234 to rotate at the same speed. The second and third gear sliding sleeve 238 remains in the middle of the second and third gear holders 236, allowing the second and third gear driven gears 232 and 233 to rotate freely. Power is input from the drive motor 1 and transmitted along the following route: first gear shaft 21 → first gear driven gear 224 → second gear shaft 221 → first gear driven gear 231 → first gear holder 235 → third gear shaft 234 → third gear driven gear 241 → differential case 242. Ultimately, power is transmitted through the differential to the left and right axle shafts 244, providing power to the wheels.

[0028] When second gear is engaged, the second / third gear sliding sleeve 238 moves leftward, connecting it to the second / third gear holder 236 and the second gear driven gear 232, allowing the second gear driven gear 232 and the third gear shaft 234 to rotate at the same speed. The first gear sliding sleeve 237 remains in the center of the first gear holder 235, allowing the first gear driven gear 231 and the third gear driven gear 233 to rotate freely. Drive motor 1 inputs power, which is transmitted along the following path: first gear shaft 21 → first gear driven gear 224 → second gear driving gear 222 → second gear driven gear 232 → second / third gear holder 236 → third gear shaft 234 → third gear driven gear 241 → differential case 242. Ultimately, the power is transmitted through the differential to the left / right half shafts 244, providing power to the wheels.

[0029] When third gear is engaged, the second- and third-gear sliding sleeve 238 moves rightward, connecting it to the second- and third-gear gear holder 236 and the third-gear driven gear 233, allowing the third-gear driven gear 233 and the third-stage gear shaft 234 to rotate at the same speed. The first-gear sliding sleeve 237 remains in the center of the first-gear gear holder 235, allowing the first-gear driven gear 231 and the second-gear driven gear 232 to rotate freely. Drive motor 1 inputs power, which is transmitted along the following path: first-stage gear shaft 21 → first-stage driven gear 224 → third-gear driving gear 223 → third-gear driven gear 233 → second- and third-gear gear holder 236 → third-stage gear shaft 234 → third-stage driven gear 241 → differential case 242. Ultimately, the power is transmitted through the differential to the left and right half-shafts 244, providing power to the wheels.

[0030] The three-speed electric drive axle provided in this embodiment can take into account both transmission performance and structural cost, and assist pure electric heavy-duty trucks in achieving the goals of lightweight, high performance and long endurance.

[0031] The above description is merely an embodiment of the present invention. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. A person of ordinary skill in the art is aware of all common technical knowledge in the technical field to which the utility model belongs before the application date or priority date, is able to obtain all existing technologies in the field, and has the ability to apply conventional experimental means before that date. A person of ordinary skill in the art can, under the guidance of this application, improve and implement the present scheme in combination with his or her own abilities. Some typical known structures or methods should not become an obstacle for a person of ordinary skill in the art to implement the present application. It should be pointed out that a person of ordinary skill in the art can make several variations and improvements without departing from the structure of the present invention. These should also be considered as the scope of protection of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A three-speed electric drive axle, characterized in that: include: A first-stage gear shaft, a second-stage gear shaft, and a third-stage gear shaft arranged in parallel; and, a primary driven gear, a first gear driven gear, a second gear driving gear, a second gear driven gear, a third gear driving gear, a third gear driven gear, a first gear gear holder, and second and third gear gear holders; The first-stage gear shaft is meshed with the first-stage driven gear; the first-stage gear shaft is transmission-connected to the driving source; the second-stage gear shaft is meshed with the first-speed driven gear; the second-speed driving gear, the first-stage driven gear and the third-speed driving gear are sequentially arranged on the second-speed gear shaft; the second-speed driving gear is meshed with the second-speed driven gear, and the third-speed driving gear is meshed with the third-speed driven gear; The three-stage gear shaft is meshed with the three-stage driven gear; the first-gear driven gear, first-gear gear seat, second-gear driven gear, second- and third-gear gear seats and third-gear driven gear are sequentially arranged on the three-stage gear shaft; the first-gear gear seat is also provided with a first-gear sliding gear sleeve; the second- and third-gear gear seats are also provided with second- and third-gear sliding gear sleeves.

2. A three-speed electric drive axle according to claim 1, characterized in that: The first-stage gear shaft, the second-stage gear shaft and the third-stage gear shaft are all arranged inside the transmission housing.

3. The three-speed electric drive axle according to claim 2, characterized in that: Both ends of the first-stage gear shaft, the second-stage gear shaft and the third-stage gear shaft are connected to the transmission housing through a bearing respectively.

4. The three-speed electric drive axle according to claim 1, characterized in that: The first gear gear seat, the second gear gear seat and the third gear gear seat are rigidly connected to the third gear shaft.

5. The three-speed electric drive axle according to claim 1, characterized in that: The first gear driven gear, the second gear driven gear and the third gear driven gear are loosely sleeved on the three-stage gear shaft through a needle roller bearing respectively.

6. The three-speed electric drive axle according to claim 1, characterized in that: The first gear sliding gear sleeve is in sliding cooperation with the first gear gear seat; the second and third gear sliding gear sleeves are in sliding cooperation with the second and third gear gear seats.

7. The three-speed electric drive axle according to claim 1, characterized in that: The three-stage driven gear is rigidly connected to the differential case.

8. The three-speed electric drive axle according to claim 7, characterized in that: The differential is respectively connected to the left half shaft and the right half shaft of the vehicle driving wheel.

9. The three-speed electric drive axle according to claim 2, characterized in that: The driving source is a driving motor; the driving motor is arranged outside the transmission housing.

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