Three-gear transmission structure of electric drive axle of commercial vehicle

Abstract

The commercial vehicle electric drive axle three-gear transmission structure comprises a motor and an input shaft, and an input-stage driving gear is arranged on the input shaft and meshed with an input-stage driven gear on an intermediate shaft; the first-gear driving gear and the third-gear driving gear are arranged on the intermediate shaft and are respectively meshed with the first-gear driven gear and the third-gear driven gear; a first-gear driven gear and a third-gear driven gear are hollowly sleeved on an output shaft through a needle bearing, power is transmitted to the output shaft through a gear shifting sliding sleeve structure, an output-stage driving gear is fixed on the output shaft and meshed with the output-stage driven gear to transmit first-gear power and third-gear power to a differential mechanism shell, and the first-gear power and the third-gear power are transmitted to wheels through a differential mechanism and a half shaft to achieve first-gear and third-gear mode driving. The second-gear transmission gear is hollowly sleeved on the differential mechanism shell through a needle bearing and is meshed with the first-gear driven gear; and when the second-gear shifting sliding sleeve structure is in gear engagement, the differential mechanism and the half shaft transmit power to wheels to realize second-gear mode driving. A three-gear transmission structure is adopted, the speed ratio stage difference is reasonable, power transition between gears is more stable, and the transmission high-efficiency area is wider.

Description

Technical Field

[0001] The invention belongs to the technical field of electric drive axles for commercial vehicles and relates to a three-speed transmission structure for an electric drive axle. Background Art

[0002] In recent years, with the rapid development of new energy technology for passenger cars and the increasing maturity of three-electric technology, new energy for commercial vehicles has also ushered in explosive growth. Especially under the background of overall negative growth of traditional fuel commercial vehicles, new energy vehicles have rebounded sharply against the trend. As the most advanced form of new energy technology for commercial vehicles, electric drive axle technology is favored by OEMs, especially new car-making forces, because of its short transmission path and high transmission efficiency. Compared with central vertical new energy vehicles, due to the limitation of the drive shaft, the bulky battery pack is usually located behind the cab, which makes the center of gravity of the whole vehicle higher and reduces the stability of the whole vehicle. The application of electric drive axle technology saves the drive shaft and helps to lighten the whole vehicle. At the same time, the battery pack can be assembled on the frame, the overall center of gravity of the vehicle is lower, and high-speed driving is more stable and safer. However, the electric drive axle technology is relatively complex, and two-speed electric drive axles are more common. This type of electric drive axle mostly uses traditional stamping and welding bridge shell or casting bridge shell technology, which is mainly manifested in low bridge shell cost and mature and reliable technology. The three-speed electric drive axle structure mostly adopts planetary gear trains, but the use of planetary gear trains means that the bridge housing can only adopt the emerging segmented bridge housing technology. This type of technology has not been widely verified in the market and has poor reliability. Currently, there are few complete vehicle matches and it is mostly seen in various exhibitions.

[0003] Traditional punched and welded bridge housings mostly use a two-speed transmission structure, which is mainly restricted by the circular bridge housing interface. While not increasing the bridge housing cost, ensuring reliability, further reducing the gear ratio difference, improving the smoothness of power transition between different gears, and not producing obvious power setbacks have always been one of the difficulties in the research of electric drive axle technology. This essentially requires the development of a three-speed electric drive axle structure. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a three-speed transmission structure for a commercial vehicle electric drive axle, so as to realize the development of a three-speed electric drive axle structure under a traditional circular stamped and welded bridge housing, thereby reducing development costs, improving technological advancement, and satisfying the reliability of the electric drive axle.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0006] A three-speed transmission structure of an electric drive axle for a commercial vehicle, comprising a motor, an input shaft, an input-stage driving gear, a bearing, a third-speed driving gear, an intermediate shaft, an input-stage passive gear, an output shaft, a third-speed passive gear, a first- and third-speed shifting sleeve structure, a first-speed passive gear, a first-speed driving gear, an output-stage driving gear, an output-stage passive gear, a differential, a second-speed transmission gear, a second-speed shifting sleeve structure, a left half shaft, and a right half shaft;

[0007] The input shaft is connected to the motor shaft via a spline and supported and positioned by a pair of bearings; the input shaft is fixedly connected to the input stage driving gear;

[0008] The third gear driving gear, the input stage passive gear and the first gear driving gear are all fixedly connected to the intermediate shaft respectively, and the intermediate shaft is supported and positioned by a pair of bearings; the input stage passive gear is meshed with the input stage driving gear for transmission;

[0009] The third-gear passive gear and the first-gear passive gear are loosely sleeved on the output shaft through needle bearings; a third-gear shift sliding sleeve structure is arranged on the output shaft, and the output-stage active gear is fixedly connected to the output shaft; the first-gear passive gear meshes with the first-gear active gear for transmission, and the third-gear passive gear meshes with the third-gear active gear for transmission;

[0010] The output stage passive gear is fixedly connected to the differential housing and meshes with the output stage active gear for transmission; the second gear transmission gear is loosely sleeved on the differential housing through a needle bearing and meshes with the first gear passive gear for transmission; the second gear shift sliding sleeve structure is arranged on the differential housing;

[0011] The left and right half shafts are connected to the differential through splines to output power to the wheels and drive the entire vehicle.

[0012] The present invention also includes the following technical features:

[0013] Specifically, the connection between the input shaft and the input-stage driving gear includes a key connection, an interference connection, or being combined into a gear shaft part.

[0014] Specifically, the third-speed driving gear, the input-stage driven gear, the first-speed driving gear and the intermediate shaft are fixedly connected in a manner that includes a key connection, an interference connection and a gear shaft structure.

[0015] Specifically, the connection method of fixing the output stage driving gear to the output shaft includes a key connection and an integral gear shaft structure, and the output shaft is supported and positioned by a pair of bearings.

[0016] Specifically, the three-speed shift sleeve structure can realize power transmission by fixing the first-speed passive gear with the output shaft through a sliding spline, and the third-speed passive gear can idle on the output shaft; the three-speed shift sleeve structure can also realize power transmission by fixing the third-speed passive gear with the output shaft through a sliding spline, and the first-speed passive gear can idle on the output shaft.

[0017] Specifically, the output stage driven gear is fixedly connected to the housing of the differential by bolt connection and key connection; the differential housing is supported and positioned by a pair of bearings.

[0018] Specifically, the second-gear shift sleeve structure can realize power transmission by fixedly connecting the differential housing and the second-gear transmission gear via a sliding spline.

[0019] Specifically, the three-speed transmission structure also includes a power take-off output shaft, a power take-off gear, and a power take-off shift sleeve structure; the power take-off gear is loosely sleeved on the power take-off shaft through a needle bearing, the power take-off shift sleeve structure is arranged on the power take-off shaft, and the power take-off gear is meshed with the second-speed transmission gear for transmission.

[0020] Specifically, the power take-off shift sleeve structure can realize power transmission by fixing the power take-off shaft and the power take-off gear through a sliding spline through an operating mechanism. The power is output by the power take-off shaft and can drive the oil pump to realize the power take-off function; the power take-off shaft is supported and positioned by bearings.

[0021] Specifically, the output ends of the left half shaft and the right half shaft are fixedly connected to the sun gear of the left wheel side planetary gear set and the sun gear of the right wheel side planetary gear set through splines, and the torque transmitted by the differential is further amplified through the planetary gear set to drive the wheels to rotate.

[0022] Compared with the prior art, the present invention has the following technical effects:

[0023] The transmission structure of the three-speed electric drive axle for commercial vehicles of the present invention adopts a parallel shaft structure, with a compact overall space, which is suitable for the traditional circular punching and welding bridge housing structure, breaking the technical barrier that the traditional punching and welding bridge housing can only develop a two-speed electric drive axle. It not only takes into account the reliability of the traditional integrated bridge housing, but also reduces the difference between the speed ratios of different gears, making the power transition between different gears smoother and without power shocks.

[0024] The transmission structure of the three-speed electric drive axle for commercial vehicles of the present invention can be directly adapted to medium and light trucks without wheel-end deceleration; when the wheel-end deceleration is used, the maximum output torque of the single-motor electric drive axle can reach more than 40,000 Nm, which is adapted to medium and heavy trucks, and the dual-bridge mode can match 49-ton 6×4 models; when the wheel-end deceleration is used, the maximum output torque of the dual-motor electric drive axle can reach more than 80,000 Nm, which is adapted to 49-ton 4×2 heavy trucks. Various application modes are configured according to the needs of the whole vehicle. The three-speed electric drive axle of this specification matches the traditional integrated circular bridge housing.

[0025] The transmission structure of the three-speed electric drive axle for commercial vehicles of the present invention can also adopt a cast non-circular axle housing, and can also be applied to a segmented axle housing. Compared with the planetary gear train adopted in the transmission part, the transmission structure of the three-speed electric drive axle of the present invention is more reliable and the service life of the transmission part is longer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the transmission structure of the three-speed electric drive axle of a commercial vehicle according to the present invention.

[0027] Figure 2 This is a schematic diagram of another transmission structure of a three-speed electric drive axle for commercial vehicles according to the present invention.

[0028] The meaning of each number in the figure is:

[0029] 1. Motor, 2. Input shaft, 3. Input stage driving gear, 4. Bearing, 5. Third gear driving gear, 6. Intermediate shaft, 7. Input stage passive gear, 8. Output shaft, 9. Third gear passive gear, 10. First and third gear shift sleeve structure, 11. First gear passive gear, 12. First gear driving gear, 13. Output stage driving gear, 14. Output stage passive gear, 15. Differential, 16. Second gear transmission gear, 17. Power take-off output shaft, 18. Power take-off gear, 19. Power take-off shift sleeve structure, 20. Second gear shift sleeve structure, 21. Left half shaft, 22. Right half shaft, 23. Left wheel side planetary gear, 24. Right wheel side planetary gear, 25. Wheel. DETAILED DESCRIPTION

[0030] The present invention provides a three-speed transmission structure of an electric drive axle for commercial vehicles, comprising a motor and an input shaft, wherein an input-stage driving gear is fixedly connected to the input shaft, and the motor power is transmitted to an intermediate shaft fixedly connected to the input-stage passive gear by meshing with the input-stage passive gear. A first-speed driving gear and a third-speed driving gear are fixedly connected to the intermediate shaft, and the power is transmitted to the first-speed passive gear and the third-speed passive gear respectively by meshing. The first-speed passive gear and the third-speed passive gear are loosely sleeved on the output shaft through a needle bearing, and the power is transmitted to the output shaft through a shift sleeve structure, and the output-stage driving gear is fixed on the output shaft, and the first- and third-speed power is transmitted to the differential housing by meshing with the output-stage passive gear, and is further transmitted to the wheels through the differential and the half shaft, so as to realize driving in the first- and third-speed modes. When the first and third gear shift sleeves are in neutral, the output shaft has no power transmission. When the second gear shift sleeve structure is connected to the second gear transmission gear, the first gear passive gear is used as the intermediate gear to transmit the power of the intermediate shaft to the differential housing, and further transmitted to the wheels through the differential and the half shaft, so as to realize the second gear mode driving. As an optional structure, the power take-off can be additionally provided with a power take-off shaft, a power take-off gear, and a power take-off shift sleeve structure according to the requirements of the whole vehicle, and the power take-off can be realized through the second gear transmission gear. In order to further improve the wheel end torque, the left and right half shafts can be further equipped with a wheel side reduction mechanism. The present invention reduces the difficulty of arranging the commercial vehicle electric drive system on the whole vehicle through the reasonable arrangement of the component structure, the overall integration, and the compact structure, and greatly reduces the risk of interference with other structures, and has strong reliability. At the same time, due to the use of a three-speed transmission structure, the speed ratio difference is more reasonable, the power transition between different gears is smoother, and the transmission high efficiency area is wider.

[0031] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0032] Example:

[0033] like Figure 1 As shown, the present embodiment provides a three-speed transmission structure of an electric drive axle for a commercial vehicle, comprising a motor 1, an input shaft 2, an input-stage driving gear 3, a bearing 4, a third-speed driving gear 5, an intermediate shaft 6, an input-stage passive gear 7, an output shaft 8, a third-speed passive gear 9, a first- and third-speed shift sleeve structure 10, a first-speed passive gear 11, a first-speed driving gear 12, an output-stage driving gear 13, an output-stage passive gear 14, a differential 15, a second-speed transmission gear 16, a second-speed shift sleeve structure 20, a left half shaft 21, and a right half shaft 22.

[0034] The input shaft 2 is connected to the motor shaft through a spline, and the power is input through the motor; and is supported and positioned by a pair of bearings 4; the input shaft 2 is fixedly connected to the input stage driving gear 3. The third gear driving gear 5, the input stage passive gear 7, and the first gear driving gear 12 are all fixedly connected to the intermediate shaft 6, which is supported and positioned by a pair of bearings; the input stage passive gear 7 is meshed with the input stage driving gear 3 for transmission, receiving the power from the input shaft, and realizing the power transmission from the input shaft to the intermediate shaft. The third gear passive gear 9 and the first gear passive gear 11 are sleeved on the output shaft 8 through a needle bearing and can idly rotate on the output shaft; a third gear shift sleeve structure 10 is arranged on the output shaft 8, and the output stage driving gear 13 is fixedly connected to the output shaft 8; the first gear passive gear 11 is meshed with the first gear driving gear 12 for transmission, and when the first-third gear shift sleeve structure is shifted to the first gear, the first gear power transmission can be realized; the third gear passive gear 9 is meshed with the third gear driving gear 5 for transmission, and when the first-third gear shift sleeve structure is shifted to the third gear, the third gear power transmission can be realized; the output shaft 8, the third gear passive gear 9, the first-third gear shift sleeve structure 10, the first gear passive gear 11, the output stage driving gear 13 and a pair of supporting bearings together constitute the output shaft assembly; the output stage passive gear 14 is fixedly connected to the housing of the differential 15, and meshes with the output stage driving gear 13 for transmission; the second gear transmission gear 16 is idled on the housing of the differential 15 through a needle roller and can idling, and meshes with the first gear passive gear 11 for transmission; the second gear shift sliding sleeve structure 20 is arranged on the housing of the differential 15; the output stage passive gear 14, the differential 15, the second gear transmission gear 16, the second gear shift sliding sleeve structure 20 and a pair of bearings together constitute the differential output assembly; the left half shaft 21 and the right half shaft 22 are connected to the differential 15 through splines to realize power output to the wheels 25 to drive the whole vehicle to travel.

[0035] In the first and third gears, the power is transmitted to the output shaft through the first and third gear gears via the intermediate shaft, and the second gear shift sleeve structure is in neutral gear; the output stage driving gear is meshed with the output stage passive gear, and the first and third gear power is transmitted from the output shaft to the differential housing, and further transmitted to the left and right half shafts, driving the vehicle to travel in the first or third gear; the first and third gear shift sleeve structure is in neutral gear, and the output shaft cannot transmit power at this time. The second gear shift sleeve structure is connected to the second gear transmission gear, and the power will be directly transmitted from the intermediate shaft to the differential housing with the first gear passive gear acting as an intermediate gear, and further transmitted to the left and right half shafts, driving the vehicle to travel in the second gear. In order to further increase the wheel-end output torque, a wheel-end reduction planetary gear system can be added.

[0036] The connection between the input shaft 2 and the input-stage driving gear 3 includes a key connection and an interference connection; optionally, the input shaft 2 and the input-stage driving gear 3 can also be combined into one gear shaft.

[0037] The third gear driving gear 5 , the input stage driven gear 7 , and the first gear driving gear 12 are all fixedly connected to the intermediate shaft 6 in a manner including key connection, interference connection, gear shaft structure, etc.; the first gear driving gear 12 can also form a gear shaft with the intermediate shaft 6 .

[0038] The connection method of the output stage driving gear 13 fixed to the output shaft 8 includes key connection and integral gear shaft structure. The output stage gear 13 and the output shaft 8 are fixedly connected together or combined into one gear shaft. The output shaft 8 is supported and positioned by a pair of bearings.

[0039] The first gear and the third gear can be selected through the three-speed shift sleeve structure 10, and the power can be transmitted to the output shaft through the meshing of the corresponding gear gears. The three-speed shift sleeve structure 10 can realize the power transmission by fixing the first gear passive gear 11 with the output shaft 8 through the sliding spline through the operating structure, and the third gear passive gear 9 can be idle on the output shaft 8; the three-speed shift sleeve structure 10 can also realize the power transmission by fixing the third gear passive gear 9 with the output shaft 8 through the sliding spline through the operating structure, and the first gear passive gear 11 can be idle on the output shaft 8.

[0040] The connection methods for fixing the output stage driven gear 14 to the housing of the differential 15 include but are not limited to bolt connection, key connection, etc.; the housing of the differential 15 is supported and positioned by a pair of bearings.

[0041] The second gear shift sleeve structure 20 can realize the second gear selection; the second gear shift sleeve structure 20 can realize the fixed connection between the differential 15 housing and the second gear transmission gear 16 through the sliding spline through the operating mechanism to realize power transmission.

[0042] The three-speed transmission structure also includes a power take-off output shaft 17, a power take-off gear 18, and a power take-off shift sleeve structure 19; the power take-off gear 18 is loosely sleeved on the power take-off shaft 17 through a needle bearing. When the power take-off shift sleeve is in neutral, the power take-off shaft has no power output. When the power take-off shift sleeve is combined with the power take-off gear, the power take-off shaft outputs power, which can further drive the oil pump and other work to achieve the power take-off requirements of the whole vehicle; the secondary transmission gear to the power take-off output shaft can be a primary transmission or a secondary transmission, depending on the power take-off output torque and speed requirements. The power take-off design meets the different working conditions of the whole vehicle, such as driving power take-off and parking power take-off. Without a power take-off, the corresponding transmission structure can be symmetrical about the front and rear of the bridge housing, and the front and rear two sets of transmission structures share the output stage passive gear, the second gear transmission gear, and the differential to achieve greater torque output. The power take-off gear shift sleeve structure 19 is arranged on the power take-off shaft 17, the power take-off gear 18 is meshed with the second gear transmission gear 16 to receive power, and the final power is output by the power take-off output shaft 17. The power take-off output shaft 17, the power take-off gear 18, the power take-off gear shift sleeve structure 19 and a pair of bearings together constitute the power take-off shaft assembly.

[0043] The power take-off shift sleeve structure 19 can realize power transmission by fixing the power take-off shaft 17 and the power take-off gear 18 through a sliding spline through an operating mechanism. The power is output by the power take-off shaft 17 and can drive an oil pump etc. to realize the power take-off function; the power take-off shaft 17 is supported and positioned by bearings.

[0044] The transmission between the power take-off shaft 17 and the second gear transmission gear 16 is not limited to one-stage transmission. It can be two-stage transmission according to the actual speed ratio. If it is a two-stage transmission, the power take-off gear shift sleeve structure 19 can be set on any transmission shaft according to space requirements, and the gear on the corresponding transmission shaft should be loosely sleeved on the transmission shaft through a needle bearing, and the other transmission shaft and the corresponding gear should be fixedly connected together, and the fixed connection method is not limited to splines, interference fit, etc. The power take-off shaft 17, the power take-off gear 18, and the power take-off gear shift sleeve structure 19 together constitute the power take-off output part.

[0045] The power take-off shaft 17 outputs power, and the vehicle power take-off oil pump can be directly driven by the power take-off shaft 17, eliminating the bulky transmission shaft and universal joint structure. Furthermore, the power take-off pump drives the hydraulic cylinder through the oil pipe to meet the power take-off requirements of the vehicle, such as unloading of dump truck compartments and rollover of tractor compartments. In addition, the power take-off structure meets different scenarios such as parking power take-off and driving power take-off, ensuring that unloading in various scenarios is easier and more thorough.

[0046] For vehicles without power take-off requirements, the three-speed transmission structure can replace some of the power take-off output components, and can be without the power take-off shaft assembly composed of the power take-off output shaft 17, the power take-off gear 18, the power take-off shift sleeve structure 19, etc. It cannot be regarded as forming a new transmission structure, does not affect its use in the whole vehicle, and does not reduce the number of driving gears.

[0047] The output ends of the left half shaft 21 and the right half shaft 22 are fixedly connected to the sun gear of the left wheel side planetary gear 23 and the sun gear of the right wheel side planetary gear 24 through splines, and drive the wheels 25 to rotate by receiving the power transmitted by the differential 15. The left half shaft 21 and the right half shaft 22 can increase the left wheel side planetary gear 23 and the right wheel side planetary gear 24 according to the torque requirements, so as to increase the torque transmitted to the wheels 25.

[0048] Further deceleration and torque increase are achieved through the left wheel side planetary gear 23 and the right wheel side planetary gear 24, which can ensure that the single-bridge output wheel end torque reaches more than 40,000 Nm, meeting the maximum climbing requirement of 30% for a 6×4 49-ton vehicle.

[0049] For vehicles with low wheel end torque requirements such as medium and light trucks, Figure 2The three-speed transmission structure can replace some components of the left wheel side planetary gear 23 and the right wheel side planetary gear 24, and cannot be regarded as forming a new transmission structure, does not affect its use in the whole vehicle, and does not reduce the number of driving gears.

[0050] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0051] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0052] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A three-speed transmission structure for an electric drive axle of a commercial vehicle, characterized in that: It comprises a motor (1), an input shaft (2), an input-stage driving gear (3), a bearing (4), a third-speed driving gear (5), an intermediate shaft (6), an input-stage passive gear (7), an output shaft (8), a third-speed passive gear (9), a first- and third-speed gearshift sliding sleeve structure (10), a first-speed passive gear (11), a first-speed driving gear (12), an output-stage driving gear (13), an output-stage passive gear (14), a differential (15), a second-speed transmission gear (16), a second-speed gearshift sliding sleeve structure (20), a left half shaft (21), and a right half shaft (22); The input shaft (2) is connected to the motor shaft via a spline and is supported and positioned by a pair of bearings (4); the input shaft (2) is fixedly connected to the input stage driving gear (3); The third gear driving gear (5), the input stage passive gear (7), and the first gear driving gear (12) are all fixedly connected to the intermediate shaft (6), and the intermediate shaft (6) is supported and positioned by a pair of bearings; the input stage passive gear (7) is meshed with the input stage driving gear (3) for transmission; The third-gear passive gear (9) and the first-gear passive gear (11) are loosely sleeved on the output shaft (8) via a needle bearing; a third-gear shift sliding sleeve structure (10) is arranged on the output shaft (8); the output-stage active gear (13) is fixedly connected to the output shaft (8); the first-gear passive gear (11) meshes with the first-gear active gear (12) for transmission, and the third-gear passive gear (9) meshes with the third-gear active gear (5) for transmission; The output-stage passive gear (14) is fixedly connected to the housing of the differential (15) and meshes with the output-stage active gear (13) for transmission; the second-gear transmission gear (16) is loosely sleeved on the housing of the differential (15) via a needle bearing and meshes with the first-gear passive gear (11) for transmission; the second-gear shift sliding sleeve structure (20) is arranged on the housing of the differential (15); The left half shaft (21) and the right half shaft (22) are connected to the differential (15) via splines, so that power is output to the wheels (25) to drive the entire vehicle.

2. The three-speed transmission structure of the commercial vehicle electric drive axle according to claim 1, characterized in that: The connection between the input shaft (2) and the input-stage driving gear (3) includes key connection, interference connection, or merging into a gear shaft part.

3. The three-speed transmission structure of the commercial vehicle electric drive axle according to claim 1, characterized in that: The third gear driving gear (5), the input stage driven gear (7), the first gear driving gear (12) and the intermediate shaft (6) are fixedly connected in a manner including a key connection, an interference connection and a gear shaft structure.

4. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 1, characterized in that: The connection method of fixing the output stage driving gear (13) to the output shaft (8) includes key connection and integral gear shaft structure, and the output shaft (8) is supported and positioned by a pair of bearings.

5. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 1, characterized in that: The three-speed gearshift sliding sleeve structure (10) can realize power transmission by fixing the first-speed passive gear (11) with the output shaft (8) through a sliding spline, and the third-speed passive gear (9) can idle on the output shaft (8); the three-speed gearshift sliding sleeve structure (10) can also realize power transmission by fixing the third-speed passive gear (9) with the output shaft (8) through a sliding spline, and the first-speed passive gear (11) can idle on the output shaft (8).

6. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 1, characterized in that: The output stage driven gear (14) is fixedly connected to the housing of the differential (15) by bolt connection and key connection; the housing of the differential (15) is supported and positioned by a pair of bearings.

7. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 1, characterized in that: The second-gear shift sliding sleeve structure (20) can realize power transmission by fixedly connecting the differential (15) housing and the second-gear transmission gear (16) via sliding splines.

8. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 1, characterized in that: The three-speed transmission structure also includes a power take-off output shaft (17), a power take-off gear (18), and a power take-off gear shifting sleeve structure (19); the power take-off gear (18) is loosely sleeved on the power take-off shaft (17) via a needle bearing, the power take-off gear shifting sleeve structure (19) is arranged on the power take-off shaft (17), and the power take-off gear (18) is meshed with the second-speed transmission gear (16) for transmission.

9. The three-speed transmission structure of the commercial vehicle electric drive axle as claimed in claim 8, characterized in that: The power take-off gear shift sleeve structure (19) can realize power transmission by fixedly connecting the power take-off shaft (17) and the power take-off gear (18) through a sliding spline through an operating mechanism; the power is output by the power take-off shaft (17) and can drive an oil pump to realize the power take-off function; the power take-off shaft (17) is supported and positioned by a bearing.

10. The three-speed transmission structure of the commercial vehicle electric drive axle according to claim 1, characterized in that: The output ends of the left half shaft (21) and the right half shaft (22) are fixedly connected to the sun gear of the left wheel side planetary gear (23) and the sun gear of the right wheel side planetary gear (24) through splines, respectively, and the torque transmitted by the differential (15) is further amplified through the planetary gear, so as to drive the wheel (25) to rotate.

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