Weight distribution balanced single-motor three-gear electric drive axle and vehicle

Abstract

The utility model discloses a single-motor three-gear electric drive axle with balanced weight distribution and a vehicle, which belong to the technical field of new energy automobile electric drive systems and comprise a drive motor, an input shaft, an intermediate shaft component, a transmission gear set, a differential mechanism assembly and a half shaft, and the intermediate shaft component, the transmission gear set, the differential mechanism assembly and the half shaft are arranged on two sides of the axle. The driving motor is connected with the input shaft, and the intermediate shaft assembly and the transmission gear set are arranged on the two radial sides of the half shaft correspondingly. The input shaft selectively transmits power to a second-third-gear intermediate shaft or a first-gear intermediate shaft of the intermediate shaft assembly through the transmission gear set and the gear selection mechanism. Power of the differential mechanism assembly is transmitted to the planet row speed reducing mechanism through the transmission gear set, output to the differential mechanism shell and output drive through the half shaft. The transmission gear and the shaft system are arranged on the two sides of the axle to balance the weight, the time of the motor running in an efficient interval is prolonged through three-gear speed change, energy consumption is reduced, the large reduction ratio is obtained through the planet row speed reducer, the wheel end output torque is improved, and practicability and adaptability are achieved.

Description

Technical Field

[0001] This utility model belongs to the technical field of electric drive systems for new energy vehicles, specifically relating to a single-motor three-speed electric drive axle with balanced weight distribution and a vehicle. Background Technology

[0002] In the commercial vehicle sector, electric drive axle technology, as the core transmission device for new energy trucks and tractors, is undergoing a transformation and upgrade from a single reducer to multi-speed transmission in order to improve the efficiency, power and economy of electric drive systems.

[0003] Currently, existing two-speed electric drive axle products on the market suffer from problems such as excessively large axial dimensions and uneven weight distribution. Most mainstream solutions employ parallel shaft single-stage or two-stage reduction structures, which, while offering the advantage of compact structure, suffer from low efficiency at high speeds and poor adaptability to complex road conditions. The industry's technical pain points focus on how to achieve a balance between multi-speed transmission, lightweight design, and reliability, as well as the coordinated optimization of the transmission system's spatial layout and NVH performance. In summary, in current multi-speed electric drive axle transmissions, the gear sets of a single-motor multi-speed transmission are concentrated on one side of the axle, resulting in uneven weight distribution on both sides of the axle and affecting vehicle handling stability; the limited number of gears leads to insufficient fuel economy, and single-speed or two-speed solutions make it difficult to keep the motor operating in its efficient range across all operating conditions for extended periods. Utility Model Content

[0004] This utility model provides a single-motor three-speed electric drive axle and vehicle with balanced weight distribution. The purpose is to solve the problems existing in current multi-speed electric drive axle transmissions, such as the gear set of a single-motor multi-speed transmission being concentrated on one side of the axle, resulting in uneven weight distribution on both sides of the axle and affecting vehicle handling stability; insufficient economy due to few gears; and difficulty in keeping the motor in the high-efficiency range of all working conditions for a long time in single-speed or two-speed schemes.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This utility model provides a single-motor three-speed electric drive axle with balanced weight distribution, including a drive motor, an input shaft, and intermediate shaft assemblies, transmission gear sets, differential assemblies, and half-shafts arranged on both sides of the axle, wherein:

[0007] The intermediate shaft assembly includes a second and third gear intermediate shaft and a first gear intermediate shaft. The drive motor is connected to the input shaft. The second and third gear intermediate shafts, the first gear intermediate shaft, and the transmission gear set are respectively arranged on the radial sides of the half shaft to balance the weight on both sides of the axle.

[0008] The input shaft can selectively transmit power to the second or third gear intermediate shaft or the first gear intermediate shaft through the transmission gear set and gear selection mechanism to achieve three-speed transmission;

[0009] The differential assembly includes a planetary gear reducer and a left and right half-shaft. The power of the differential assembly is transmitted to the planetary gear reducer via a transmission gear set, and then output to the differential housing via the planetary gear reducer, and finally driven through the left and right half-shafts.

[0010] In some embodiments, the transmission gear set includes a first-stage driving gear, a first-stage driven gear, a second-stage driving gear, a second-stage driven gear, a first-gear driving gear, a first-gear driven gear, a third-gear driving gear, a third-gear driven gear, a second-gear driving gear, a second-gear driven gear, and a first-gear intermediate shaft output gear.

[0011] The first-stage drive gear is fixedly connected to the input shaft. The second-stage drive gear and the first-stage driven gear are fixedly connected to the intermediate shaft between the second and third gears. The third-stage drive gear and the second-stage drive gear are loosely fitted onto the intermediate shaft between the second and third gears. The second-stage driven gear and the first-stage drive gear form a double gear and are loosely fitted onto the left half-shaft. The third-stage driven gear and the second-stage driven gear are loosely fitted onto the left half-shaft.

[0012] Furthermore, the input shaft selectively transmits power to the second and third gear intermediate shaft via the meshing of the first-stage driving gear and the first-stage driven gear; or via the meshing of the first-stage driving gear and the first-stage driven gear, the meshing of the second-stage driving gear and the second-stage driven gear, and the meshing of the first gear driving gear and the first gear driven gear to the first gear intermediate shaft.

[0013] Furthermore, the gear selection mechanism includes a gear shift sleeve, which is connected to the intermediate shaft key for second and third gears. The gear shift sleeve can move left and right to select whether to engage with the third gear drive gear or the second gear drive gear.

[0014] Furthermore, the planetary gear reducer includes a sun gear, planet gears, a planet carrier, and an internal gear ring. The sun gear is connected to the transmission gear set, and power is transmitted to the planet carrier via the planet gears. The internal gear ring remains stationary.

[0015] Furthermore, the first gear intermediate shaft output gear meshes with the second gear driven gear for first gear power transmission.

[0016] Furthermore, the second-gear driven gear is connected to the sun gear for second-gear power transmission; the third-gear driven gear is connected to the sun gear for third-gear power transmission.

[0017] In some implementations, an intermediate roller is added between the input shaft and the intermediate shaft for the second and third gears.

[0018] In some implementations, a reserved power take-off (PTO) interface is also included, which is connected to the differential assembly or the transmission gear set.

[0019] This utility model also provides a vehicle, which includes the above-mentioned single-motor three-speed electric drive axle with balanced weight distribution.

[0020] Compared with the prior art, the single-motor three-speed electric drive axle and vehicle with balanced weight distribution of this utility model have the following beneficial effects:

[0021] This utility model discloses a single-motor three-speed electric drive axle with balanced weight distribution. Addressing the technical problems of existing electric drive axle systems, it designs a transmission route for a single-motor three-speed electric drive axle used in new energy vehicles. This transmission route adopts a fusion scheme of a double-sided gear layout and a planetary gear reducer. Through the single-motor three-speed electric drive axle assembly, the three-speed transmission increases the time the motor operates in the high-efficiency range, reducing overall vehicle energy consumption. The transmission gears and shaft system are arranged on both sides of the axle to balance the weight on both sides of the electric drive axle. By using a planetary gear reducer, a large reduction ratio can be obtained, increasing the wheel-end output torque. Furthermore, the planetary gear reducer has a relatively compact structure and a relatively small space occupancy rate.

[0022] Furthermore, this utility model can reserve a power take-off connection port to support power output from external equipment, and can also add an intermediate wheel to meet the needs of spatial arrangement or reduction ratio. Through the design of the intermediate wheel, the transmission ratio and spatial layout can be flexibly adjusted, enhancing the practicality and applicability of the single motor three-speed electric drive bridge. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0024] Figure 1 This utility model provides a single-motor three-speed electric drive axle with balanced weight distribution and a structural schematic diagram of a single-motor three-speed electric drive axle in a vehicle.

[0025] Figure 2 This is a schematic diagram of the power transmission route of the first gear in a single-motor three-speed electric drive bridge with balanced weight distribution according to this utility model.

[0026] Figure 3 This is a schematic diagram of the power transmission route for the second gear in a single-motor three-speed electric drive bridge with balanced weight distribution according to this utility model.

[0027] Figure 4 This is a schematic diagram of the power transmission route for the three gears in a single-motor three-speed electric drive bridge with balanced weight distribution according to this utility model.

[0028] Figure 5 This is a schematic diagram of the structure of a single-motor three-speed electric drive bridge with balanced weight distribution connected to a power take-off interface according to this utility model.

[0029] Figure 6 This is a schematic diagram of the structure of a single-motor three-speed electric drive bridge with added intermediate rollers for weight distribution balance according to this utility model.

[0030] The components are as follows: 1. Drive motor; 2. Input shaft; 3. Second and third gear intermediate shaft; 4. Second gear drive gear; 5. Gear shift sleeve; 6. Third gear drive gear; 7. First gear driven gear; 8. First gear drive gear; 9. Second gear drive gear; 10. Second gear driven gear; 11. First gear drive gear; 12. Left wheel; 13. Third gear driven gear; 14. First gear driven gear; 15. First gear intermediate shaft; 16. Gear shift sleeve; 17. First gear intermediate shaft output gear; 18. Right wheel; 19. Differential housing; 20. Half-shaft gear; 21. Right half-shaft; 22. Cross shaft; 23. Differential planetary gear; 24. Sun gear; 25. Left half-shaft; 26. Planetary carrier; 27. Planetary gears; 28. Internal gear ring; 29. ​​Second gear driven gear; 30. Intermediate gear. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present 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 present invention without inventive effort are within the scope of protection of the present invention.

[0033] Similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of the embodiments of this utility model, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, they are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the utility model. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0035] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0036] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] like Figure 1 As shown, this utility model discloses a single-motor three-speed electric drive axle with balanced weight distribution, comprising a drive motor 1, an input shaft 2, and intermediate shaft assemblies, transmission gear sets, differential assemblies, and half-shafts arranged on both sides of the axle, wherein:

[0038] The intermediate shaft assembly includes a second and third gear intermediate shaft 3 and a first gear intermediate shaft 15. The drive motor 1 is connected to the input shaft 2. The second and third gear intermediate shaft 3, the first gear intermediate shaft 15, and the transmission gear set are respectively arranged on the radial sides of the half shaft to balance the weight on both sides of the axle.

[0039] The input shaft 2 can selectively transmit power to the second or third gear intermediate shaft 3 or the first gear intermediate shaft 15 through the transmission gear set and gear selection mechanism to achieve three-speed shifting;

[0040] The differential assembly includes a planetary gear reducer mechanism, and the half-shafts include a left half-shaft 25 and a right half-shaft 21. The power of the differential assembly is transmitted to the planetary gear reducer mechanism via a transmission gear set, and output to the differential housing 19 through the planetary gear reducer mechanism, and then driven through the left half-shaft 25 and the right half-shaft 21.

[0041] This invention relates to a single-motor three-speed electric drive axle. By symmetrically arranging the intermediate shaft assembly, transmission gear set, differential assembly, and half-shaft transmission gear set on both sides of the axle, it effectively balances the weight distribution on both sides of the electric drive axle, improving vehicle handling stability and avoiding the weight imbalance problem caused by traditional single-sided layouts. Employing a three-speed transmission, the meshing relationship of different gear sets allows the drive motor to operate in its high-efficiency range for extended periods, reducing overall vehicle energy consumption and enhancing adaptability to complex road conditions. Furthermore, this invention combines a planetary gear reducer mechanism and a symmetrical gear layout to solve the problem of excessively large axial dimensions in traditional multi-speed transmissions, achieving miniaturization and weight reduction of the transmission system.

[0042] In some embodiments, the single-motor three-speed electric drive bridge with balanced weight distribution of this utility model specifically includes a first-stage driving gear 8, a first-stage driven gear 7, a second-stage driving gear 9, a second-stage driven gear 10, a first-speed driving gear 11, a first-speed driven gear 14, a third-speed driving gear 6, a third-speed driven gear 13, a second-speed driving gear 4, a second-speed driven gear 29, and a first-speed intermediate shaft output gear 17. The specific relationships between the gears in the transmission gear set are as follows: the first-stage driving gear 8 is fixedly connected to the input shaft 2; the second-stage driving gear 9 and the first-stage driven gear 7 are fixedly connected to the second and third-speed intermediate shaft 3; the third-speed driving gear 6 and the second-speed driving gear 4 are loosely fitted on the second and third-speed intermediate shaft 3; the second-stage driven gear 10 and the first-speed driving gear 11 form a double gear and are loosely fitted on the left half-shaft 25; the third-speed driven gear 13 and the second-speed driven gear 29 are loosely fitted on the left half-shaft 25.

[0043] Specifically, in the single-motor three-speed electric drive bridge with balanced weight distribution of this utility model, the input shaft 2 selectively transmits power to the second and third gear intermediate shaft 3 through the meshing of the first-stage driving gear 8 and the first-stage driven gear 7; or through the meshing of the first-stage driving gear 8 and the first-stage driven gear 7, the meshing of the second-stage driving gear 9 and the second-stage driven gear 10, and the meshing of the first-speed driving gear 11 and the first-speed driven gear 14, thereby realizing three-speed transmission. Specifically, the three-speed transmission is achieved as follows: the output gear 17 of the first-speed intermediate shaft meshes with the second-speed driven gear 29 for first-speed power transmission; the second-speed driven gear 29 is connected to the sun gear 24 for second-speed power transmission; and the third-speed driven gear 13 is connected to the sun gear 24 for third-speed power transmission.

[0044] This utility model achieves three-speed transmission by selectively engaging various gears through the meshing relationship of the transmission gear set and the gear selection mechanism; by arranging the second and third gear intermediate shaft 3, the first gear intermediate shaft 15 and the transmission gear set on the radial sides of the half shaft respectively, the weight on both sides of the axle is balanced.

[0045] Furthermore, the single-motor three-speed electric drive axle of this invention, with balanced weight distribution, transmits power through the meshing of the sun gear 24, planetary gears 27, and planetary carrier 26, combined with the fixed internal gear ring 28, achieving a large reduction ratio and high torque output while maintaining a compact structure and reducing space occupation. This invention optimizes the power transmission path, reduces energy loss, and improves the transmission efficiency of each gear by directly connecting the second-speed driven gear 29 and the third-speed driven gear 13 to the sun gear 24, and by having the first-speed intermediate shaft output gear 17 mesh with the second-speed driven gear 29.

[0046] The gear selection mechanism of this utility model includes a gear shift sleeve 5, which is keyed to the second and third gear intermediate shaft 3. The gear shift sleeve 5 can move left and right to select engagement with the third gear drive gear 6 or the second gear drive gear 4. This utility model, through the independent layout of the second and third gear intermediate shaft 3 and the first gear intermediate shaft 15, clearly defines the power transmission path with the first-stage driven gear 7 fixedly connected, ensuring transmission stability and reliability. The left and right movement of the gear shift sleeve 5 selects the gear, simplifying the shifting operation and improving shifting accuracy and response speed.

[0047] This utility model also provides a vehicle, which includes a single-motor three-speed electric drive axle with balanced weight distribution.

[0048] The following detailed description of a single-motor three-speed electric drive bridge with balanced weight distribution is provided through specific embodiments.

[0049] like Figure 1 As shown, the single-motor three-speed electric drive axle assembly of this utility model includes a drive motor 1 connected to an input shaft 2; a first-stage drive gear 8 fixedly connected to the input shaft 2; and components on the second- and third-speed intermediate shaft 3 including a second-stage drive gear 9, a first-stage driven gear 7, a third-speed drive gear 6, a gear engaging sleeve 5, and a second-speed drive gear 4. The second-stage drive gear 9 and the first-stage driven gear 7 are fixedly connected to the second- and third-speed intermediate shaft 3, while the third-speed drive gear 6 and the second-speed drive gear 4 are loosely fitted onto the second- and third-speed intermediate shaft 3. The gear engaging sleeve 5 is keyed to the second- and third-speed intermediate shaft 3, allowing it to move left and right to engage with either the third-speed drive gear 6 or the second-speed drive gear 4, thus transmitting power from the second- and third-speed intermediate shaft 3 to either the third-speed drive gear 6 or the second-speed drive gear 4.

[0050] In this utility model, the components on the left half-shaft 25 and the right half-shaft 21 include a left wheel 12, a right wheel 18, a second-stage driven gear 10, a first-speed driving gear 11, a third-speed driven gear 13, a second-speed driven gear 29, a sun gear 24, a planetary carrier 26, planetary gears 27, an internal gear ring 28, and the main components of the differential assembly, the differential housing 19, half-shaft gears 20, a cross shaft 22, and a differential planetary gear 23. The second-stage driven gear 10 and the first-speed driving gear 11 are double gears, loosely fitted on the left half-shaft 25, and do not directly transmit power from the gears to the half-shaft. The third-speed driven gear 13 and the second-speed driven gear 29 are loosely fitted on the left half-shaft 25, and do not directly transmit power from the gears to the half-shaft. The internal gear ring 28 does not rotate. When power is transmitted, it is transmitted to the differential assembly via the sun gear 24, planetary gears 27, and planetary carrier 26, and then to the left half-shaft 25 and the right half-shaft 21.

[0051] In this utility model, the components on the first gear intermediate shaft 15 include a first gear driven gear 14, a gear engagement sleeve 16, and a first gear intermediate shaft output gear 17. The first gear driven gear 14 is loosely fitted on the first gear intermediate shaft 15. The gear engagement sleeve 16 and the first gear intermediate shaft 15 are connected by a key, allowing it to move left and right to engage or disengage with the first gear driving gear 14. The first gear intermediate shaft output gear 17 is fixedly connected to the first gear intermediate shaft 15.

[0052] like Figure 2 As shown, in this utility model, if the gear shift sleeve 5 is in the middle position and does not engage with the gears on both sides, while the gear shift sleeve 16 engages with the first gear driven gear 14, the electric drive axle is in the first gear working state. When the electric drive axle is in the first gear working state, the power transmission route is as follows: the drive motor transmits power to the input shaft 2, then through the meshing of the first-stage drive gear 8 and the first-stage driven gear 7, it is transmitted to the second and third gear intermediate shaft 3, then through the meshing of the second-stage drive gear 9 and the second-stage driven gear 10, it is transmitted to the first gear drive gear 11, which forms a double gear with the second-stage driven gear 10. The first gear drive gear 11 meshes with the first gear driven gear 14, transmitting power to the first gear intermediate shaft 15, then through the first gear intermediate shaft output gear 17 and the second gear driven gear 29, it is transmitted to the sun gear 24, then through the planetary gear 27 and the planet carrier 26, it is transmitted to the differential assembly, and finally to the left half shaft 25 and the right half shaft 21.

[0053] like Figure 3 As shown in the present invention, when the shift sleeve 5 engages with the second gear drive gear 4 while the shift sleeve 16 does not engage with the gear, the electric drive axle is in the second gear working state. When the electric drive axle is in the second gear working state, the power transmission route is as follows: the drive motor transmits power to the input shaft 2, then through the meshing of the first-stage drive gear 8 and the first-stage driven gear 7 to the second-third gear intermediate shaft 3, then through the meshing of the second-stage drive gear 4 and the second-stage driven gear 29 to the sun gear 24, then through the planetary gears 27 and the planet carrier 26 to the differential assembly, and finally to the left half shaft 25 and the right half shaft 21.

[0054] like Figure 4 As shown in the present invention, when the shift sleeve 5 engages with the third gear drive gear 6 but the shift sleeve 16 does not engage with the gear, the electric drive axle is in the third gear working state. When the electric drive axle is in the third gear working state, the power transmission route is as follows: the drive motor transmits the power to the input shaft 2, then through the meshing of the first-stage drive gear 8 and the first-stage driven gear 7 to the second-third gear intermediate shaft 3, then through the meshing of the third gear drive gear 6 and the third gear driven gear 13 to the sun gear 24, then through the planetary gears 27 and the planet carrier 26 to the differential assembly, and finally to the left half shaft 25 and the right half shaft 21.

[0055] like Figure 5 and Figure 6As shown, as a preferred embodiment, the single-motor three-speed electric drive axle of this utility model with balanced weight distribution can reserve a power take-off interface to expand external devices and support the power output of external devices, thus expanding the application scenarios of the single-motor three-speed electric drive axle and increasing the scenarios in which the vehicle can work. This utility model can also add an intermediate wheel 30 between the input shaft 2 and the second / third gear intermediate shaft 3 to meet the needs of spatial arrangement or reduction ratio. Through the design of the intermediate wheel 30, the transmission ratio and spatial layout can be flexibly adjusted, enhancing the adaptability of the single-motor three-speed electric drive axle.

[0056] Finally, it should be noted that the above description is only a preferred embodiment of this utility model and is not intended to limit this utility model in any way. Anyone skilled in the art can smoothly implement this utility model according to the description and above. However, any modifications, alterations, and variations made by those skilled in the art without departing from the scope of the technical solution of this utility model using the disclosed technical content are equivalent embodiments of this utility model. At the same time, any equivalent changes, alterations, and variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of the technical solution of this utility model.

Claims

1. A single-motor three-speed electric drive bridge with balanced weight distribution, characterized in that, Includes a drive motor (1), an input shaft (2), and intermediate shaft assemblies, transmission gear sets, differential assemblies, and half shafts arranged on both sides of the axle, wherein: The intermediate shaft assembly includes a second and third gear intermediate shaft (3) and a first gear intermediate shaft (15). The drive motor (1) is connected to the input shaft (2). The second and third gear intermediate shaft (3), the first gear intermediate shaft (15), and the transmission gear set are respectively arranged on the radial sides of the half shaft to balance the weight on both sides of the axle. The input shaft (2) can selectively transmit power to the second or third gear intermediate shaft (3) or the first gear intermediate shaft (15) through the transmission gear set and gear selection mechanism to achieve three-speed transmission; The differential assembly includes a planetary gear reducer mechanism, and the half-shaft includes a left half-shaft (25) and a right half-shaft (21). The power of the differential assembly is transmitted to the planetary gear reducer mechanism via a transmission gear set, and output to the differential housing (19) through the planetary gear reducer mechanism, and driven through the left half-shaft (25) and the right half-shaft (21).

2. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 1, characterized in that, The transmission gear set includes a first-stage driving gear (8), a first-stage driven gear (7), a second-stage driving gear (9), a second-stage driven gear (10), a first-stage driving gear (11), a first-stage driven gear (14), a third-stage driving gear (6), a third-stage driven gear (13), a second-stage driving gear (4), a second-stage driven gear (29), and a first-stage intermediate shaft output gear (17). The first-stage driving gear (8) is fixedly connected to the input shaft (2), the second-stage driving gear (9) and the first-stage driven gear (7) are fixedly connected to the second and third gear intermediate shaft (3), the third gear driving gear (6) and the second gear driving gear (4) are loosely fitted on the second and third gear intermediate shaft (3); the second-stage driven gear (10) and the first gear driving gear (11) form a double gear and are loosely fitted on the left half shaft (25), the third gear driven gear (13) and the second gear driven gear (29) are loosely fitted on the left half shaft (25).

3. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 2, characterized in that, The input shaft (2) selectively transmits power to the second and third gear intermediate shaft (3) through the meshing of the first-level driving gear (8) and the first-level driven gear (7); or through the meshing of the first-level driving gear (8) and the first-level driven gear (7), the meshing of the second-level driving gear (9) and the second-level driven gear (10), and the meshing of the first gear driving gear (11) and the first gear driven gear (14) to the first gear intermediate shaft (15).

4. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 2, characterized in that, The gear selection mechanism includes a gear sleeve (5), which is keyed to the second and third gear intermediate shaft (3). The gear sleeve (5) can move left and right to select engagement with the third gear drive gear (6) or the second gear drive gear (4).

5. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 2, characterized in that, The planetary gear reducer includes a sun gear (24), planet gears (27), a planet carrier (26), and an internal gear ring (28). The sun gear (24) is connected to the transmission gear set, and the power is transmitted to the planet carrier (26) via the planet gears (27). The internal gear ring (28) is fixed.

6. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 5, characterized in that, The first gear intermediate shaft output gear (17) meshes with the second gear driven gear (29) for first gear power transmission.

7. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 6, characterized in that, The second-gear driven gear (29) is connected to the sun gear (24) for second-gear power transmission; the third-gear driven gear (13) is connected to the sun gear (24) for third-gear power transmission.

8. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 1, characterized in that, An intermediate wheel (30) is added between the input shaft (2) and the intermediate shaft (3) of the second and third gears.

9. The single-motor three-speed electric drive bridge with balanced weight distribution according to claim 1, characterized in that, It also includes a reserved power take-off (PTO) interface, which is connected to the differential assembly or the transmission gear set.

10. A vehicle, characterized in that, The vehicle includes a single-motor three-speed electric drive axle with balanced weight distribution as described in any one of claims 1-9.

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