Coaxial electric drive axle, control method of coaxial electric drive axle and coaxial electric drive axle system

Abstract

The invention provides a coaxial electric drive bridge, a control method of the coaxial electric drive bridge and a coaxial electric drive bridge system. The coaxial electric drive axle comprises a first motor, a second motor, four planetary gear sets, a differential mechanism and a gear shifting mechanism. The electric drive axle is connected with the planetary gear set through the first motor and the second motor, and switching of power flow paths is achieved through the gear shifting sliding sleeve and the switching element set. Specifically, an output shaft of the first motor is connected with a sun gear shaft of the first planetary gear set, the second motor is connected with a planet carrier shaft of the first planetary gear set and a sun gear shaft of the second planetary gear set, an input shaft of the differential mechanism is connected with a planet carrier shaft of the second planetary gear set, and finally transmission is conducted to wheels through the third planetary gear set and the fourth planetary gear set. Through the design of the gear shifting mechanism, the power transmission path is optimized under different working conditions, the transmission ratio is dynamically adjusted, and the problem that an existing coaxial electric drive axle is difficult to adapt to complex and changeable working conditions of a new energy automobile is solved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy vehicles, and in particular to a coaxial electric drive bridge, a control method for a coaxial electric drive bridge, a coaxial electric drive bridge system, and a computer-readable storage medium. Background Art

[0002] The development of new energy vehicles has received more and more attention from the country. With the rapid development of electrification of medium and heavy commercial vehicles, matching electric drive axle systems has gradually become the mainstream. However, the current electric drive axles are difficult to meet the requirements of power and vehicle speed under different road conditions, and the electric drive axles have complex structures, low transmission efficiency, heavy weight and high cost. Summary of the invention

[0003] The main purpose of the present application is to provide a coaxial electric drive bridge, a control method of a coaxial electric drive bridge, a coaxial electric drive bridge system and a computer-readable storage medium to solve the problem that the coaxial electric drive bridge in the prior art is difficult to adapt to the complex and changeable working conditions of new energy vehicles.

[0004] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a coaxial electric drive axle is provided, including: a first motor, a second motor, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a differential and a shifting mechanism, wherein the first planetary gear set includes a switching element group, and the shifting mechanism includes a shift sleeve, wherein the output shaft of the first motor is connected to the sun gear shaft of the first planetary gear set, the input shaft and the output shaft of the second motor are respectively connected to the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set, the input shaft of the differential is connected to the planetary carrier shaft of the second planetary gear set, the two output shafts of the differential are respectively connected to the input shaft of the third planetary gear set and the input shaft of the fourth planetary gear set, the two output half shafts of the differential are respectively connected to the left and right wheels, and the shift sleeve engages with the switching element group through axial movement to switch the power flow path.

[0005] Furthermore, the shift mechanism and the differential are asymmetrically distributed on both sides of the coaxial electric drive axle, and the rotation centerline of the input shaft of the first motor, the rotation centerline of the input shaft of the second motor coincides with the rotation centerline of the output half-shaft of the electric drive axle.

[0006] Furthermore, the first motor is a dual-speed motor, and the second motor is a single-speed motor.

[0007] Further, the switching element group includes a first switching element, a second switching element and a third switching element, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planetary carrier shaft of the first planetary gear set, and the shift sleeve engages with one or more of the first switching element, the second switching element and the third switching element through axial movement to switch gears.

[0008] Furthermore, the gear mode of the coaxial electric drive axle includes a first gear mode, a second gear mode and a third gear mode. In the first gear mode, the shift sleeve interlocks the first switching element and the second switching element, in the second gear mode, the shift sleeve interlocks the second switching element and the third switching element, and in the third gear mode, the shift sleeve interlocks the second switching element.

[0009] Furthermore, the driving mode of the coaxial electric drive bridge includes a dual-motor driving mode and a single-motor driving mode, wherein the dual-motor driving mode is that the first motor and the second motor work simultaneously, and the single-motor driving mode is that the first motor works alone or the second motor works alone, in the dual-motor driving mode, the first motor is in the first gear mode or the second gear mode and the second motor is a fixed speed ratio, and in the single-motor driving mode, the first motor is in the first gear mode or the second gear mode and the second motor does not work, or the first motor does not work and the second motor is a fixed speed ratio.

[0010] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a control method for a coaxial electric drive axle is provided, including: obtaining the operating condition of the coaxial electric drive axle; determining the gear mode of the coaxial electric drive axle according to the operating condition of the coaxial electric drive axle; and based on the gear mode of the coaxial electric drive axle, controlling the shift sleeve to interlock at least part of the switching elements in the switching element group.

[0011] Further, according to the operating condition of the coaxial electric drive bridge, the gear mode of the coaxial electric drive bridge is determined, including: if the operating condition of the coaxial electric drive bridge is the first operating condition, the gear mode of the coaxial electric drive bridge is determined to be the first gear mode; if the operating condition of the coaxial electric drive bridge is the second operating condition, the gear mode of the coaxial electric drive bridge is determined to be the second gear mode; if the operating condition of the coaxial electric drive bridge is the third operating condition, the gear mode of the coaxial electric drive bridge is determined to be the third gear mode; based on the gear mode of the coaxial electric drive bridge, control The shift sleeve interlocks at least part of the switching elements in the switching element group, including: if the gear mode of the coaxial electric drive axle is the first gear mode, controlling the shift sleeve to interlock the first switching element and the second switching element in the switching element group; if the gear mode of the coaxial electric drive axle is the second gear mode, controlling the shift sleeve to interlock the second switching element and the third switching element in the switching element group; if the gear mode of the coaxial electric drive axle is the third gear mode, controlling the shift sleeve to interlock the second switching element in the switching element group.

[0012] According to another aspect of the present application, a coaxial electric drive bridge system is provided, comprising: any one of the coaxial electric drive bridges; and a controller, communicating with the coaxial electric drive bridge, for executing any one of the coaxial electric drive bridge control methods.

[0013] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the control methods for the coaxial electric drive axle.

[0014] By applying the technical solution of the present application, a coaxial electric drive axle is proposed, which includes a first motor, a second motor, a plurality of planetary gear sets, a differential and a shift mechanism. The electric drive axle is connected to the planetary gear set through the first motor and the second motor respectively, and the power flow path is switched through the shift sleeve and the switching element group. Among them, the output shaft of the first motor is connected to the sun gear shaft of the first planetary gear set, the second motor is connected to the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set, and the input shaft of the differential is connected to the planetary carrier shaft of the second planetary gear set, and is finally transmitted to the wheels through the third and fourth planetary gear sets. The present application realizes the optimized power transmission path under different working conditions through the design of the shift mechanism. This design can dynamically adjust the transmission ratio according to the actual driving requirements of the vehicle (such as climbing, accelerating, high-speed cruising, etc.), thereby solving the problem that the existing coaxial electric drive axle is difficult to apply to the complex and changeable working conditions of new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 A schematic diagram of the architecture of a coaxial electric drive bridge provided according to an embodiment of the present application is shown;

[0017] Figure 2 A schematic diagram of an application architecture of a coaxial electric drive bridge provided according to an embodiment of the present application is shown;

[0018] Figure 3 A schematic diagram of an application architecture of another coaxial electric drive bridge provided according to an embodiment of the present application is shown;

[0019] Figure 4 A schematic diagram of an application architecture of another coaxial electric drive bridge provided according to an embodiment of the present application is shown;

[0020] Figure 5 A schematic diagram of an application architecture of another coaxial electric drive bridge provided according to an embodiment of the present application is shown;

[0021] Figure 6 A schematic flow chart of a control method for a coaxial electric drive bridge provided according to an embodiment of the present application is shown.

[0022] The above drawings include the following reference numerals:

[0023] 10. First motor; 20. Second motor; 01. First planetary gear set; 02. Second planetary gear set; 03. Third planetary gear set; 04. Fourth planetary gear set; 30. Differential; 40. Shift mechanism; 50. Wheel; 60. First switching element; 70. Second switching element; 80. Third switching element. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0025] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0026] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0027] For the convenience of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0028] Electric drive axle: A device that converts electrical energy into mechanical energy, mainly used to drive vehicles or other means of transportation. It is usually composed of one or more electric motors, reducers, differentials and other components. The electric drive axle provides power through the electric motor, and the reducer adjusts the speed so that the vehicle can travel efficiently.

[0029] Coaxial electric drive axle: Coaxial electric drive axle means that the rotation centerline of the motor input shaft coincides with the rotation centerline of the electric drive axle output half shaft. This design helps to simplify the structure, improve space utilization, and reduce the complexity and cost of the transmission system.

[0030] NGW planetary gear set (New Generation Worm Gear Planetary Gear Set): A new type of planetary gear set design, often used to improve the efficiency and stability of the transmission system. Different from the traditional planetary gear set, the NGW planetary gear set adopts more advanced design concepts and materials, optimizes the gear meshing mode, and reduces friction and energy loss. The characteristics of this gear set are its high efficiency and compact structure, which can provide a larger transmission ratio and higher load capacity in a smaller volume.

[0031] As introduced in the background technology, the existing electric drive axle is difficult to meet the requirements of power and vehicle speed under different road conditions. The electric drive axle has a complex structure, low transmission efficiency, heavy weight and high cost. In order to solve the problem that the existing coaxial electric drive axle is difficult to adapt to the complex and changeable working conditions of new energy vehicles, the present application proposes a coaxial electric drive axle, a control method of a coaxial electric drive axle, a coaxial electric drive axle system and a computer-readable storage medium.

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0033] Figure 1 Schematic diagram of a coaxial electric drive bridge structure provided according to an embodiment of the present application. Figure 1As shown, a coaxial electric drive axle is provided, including: a first motor 10, a second motor 20, a first planetary gear set 01, a second planetary gear set 02, a third planetary gear set 03, a fourth planetary gear set 04, a differential 30 and a shift mechanism 40, wherein the first planetary gear set 01 includes a switching element set, and the shift mechanism 40 includes a shift sleeve.

[0034] The output shaft of the first motor is connected to the sun gear shaft of the first planetary gear set, the input shaft and output shaft of the second motor are respectively connected to the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set, the input shaft of the differential is connected to the planetary carrier shaft of the second planetary gear set, and the two output shafts of the differential are respectively connected to the input shaft of the third planetary gear set and the input shaft of the fourth planetary gear set. Figure 1 The two output half shafts of the differential are respectively connected to the left and right wheels 50, and the shift sleeve engages with the switching element group through axial movement to switch the power flow path, wherein the first planetary gear set, the second planetary gear set, the third planetary gear set and the fourth planetary gear set are four NGW planetary gear sets.

[0035] Specifically, the electric drive axle includes multiple core components: a first motor, a second motor, four planetary gear sets, a differential and a shift mechanism. The specific configuration is as follows: the first motor is responsible for providing power input and is connected to the sun gear shaft of the first planetary gear set; the second motor provides power output and is respectively connected to the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set; the first planetary gear set, the second planetary gear set, the third planetary gear set and the fourth planetary gear set are used to realize power transmission and deceleration between different gears, especially the first planetary gear set is equipped with a switching element group, which is used to realize the switching of power flow through the shift sleeve; the differential is connected to the planetary carrier shaft of the second planetary gear set, and the input shaft of the differential transmits power to the left and right wheels, and the two output shafts of the differential are respectively connected to the input shafts of the third and fourth planetary gear sets, so as to transmit to the wheels; the shift sleeve of the shift mechanism can move axially and mesh with the switching element group to realize the switching of the power flow path between different gears.

[0036] By applying the technical solution of the present application, due to the coaxial architecture design, the output shafts of the first motor and the second motor are connected to multiple planetary gear sets, and the external space occupation is reduced through a compact layout, which improves the overall integration of the system. The electric drive bridge realizes the power output of two gears through the shift mechanism, and can flexibly switch gears according to different working conditions. The meshing design of the shift sleeve and the switching element group enables the power flow path to be precisely controlled, thereby providing more efficient power transmission and a more optimized driving experience under different driving conditions. For example, when starting, a low speed gear is used to provide a higher starting torque, and when driving at high speed, it is switched to the efficient second gear to achieve lower energy consumption and smoother driving. Through the ingenious design of the four planetary gear sets, especially in the switching element group of the first planetary gear set, seamless switching and precise power transmission can be achieved. The electric bridge supports flexible switching between dual-motor and single-motor drive modes, and while ensuring power, it can also optimize energy efficiency according to load conditions to achieve lower energy consumption. Thereby solving the problem that the existing coaxial electric drive bridge is difficult to apply to the complex and changeable working conditions of new energy vehicles.

[0037] As a possible implementation method, the shift mechanism and the differential are asymmetrically distributed on both sides of the coaxial electric drive bridge, and the rotation centerline of the input shaft of the first motor and the rotation centerline of the input shaft of the second motor coincide with the rotation centerline of the output half-shaft of the electric drive bridge.

[0038] Specifically, the shift mechanism and the differential are asymmetrically distributed on both sides of the coaxial electric drive bridge. Further, the shift mechanism and the differential are distributed on both sides of the electric drive bridge to make full use of the internal space of the electric drive bridge, reduce the complexity of the system and optimize the layout. The rotation centerline of the input shaft of the first motor and the rotation centerline of the input shaft of the second motor coincide with the rotation centerline of the output half-shaft of the electric drive bridge. This design ensures the linearity of the transmission path, reduces energy loss in the transmission, and improves the transmission efficiency. In addition, the coaxial design of the electric drive bridge also optimizes the mechanical structure, making the system more compact and helping to reduce the overall weight and size.

[0039] As a possible implementation manner, the first motor is a dual-speed motor, and the second motor is a single-speed motor.

[0040] Specifically, the first motor has two different working speed gears (such as high gear and low gear), and provides different power outputs by switching gears to adapt to different working conditions. The second motor adopts a single-speed design, which is mainly used to provide constant power output without adjusting the speed according to the working conditions. The advantage of this configuration is that the two-speed motor can provide higher torque at low speeds to meet the needs of high-load conditions such as starting and climbing, and can operate more efficiently at high speeds; the single-speed motor is used to provide stable and constant power under specific working conditions to avoid unnecessary power consumption. Through this innovative configuration, the electric drive axle can achieve the best power matching under a variety of driving conditions to meet the needs of power and energy efficiency under different working conditions.

[0041] As a possible implementation, Figure 1 As shown, the switching element group includes a first switching element 60, a second switching element 70 and a third switching element 80, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planetary carrier shaft of the first planetary gear set. The shift sleeve engages with one or more of the first switching element, the second switching element and the third switching element by axial movement to switch gears.

[0042] Specifically, the first switching element is used to switch the connection between the housing shaft of the coaxial electric drive axle and the ring gear shaft of the first planetary gear set between different gears, the second switching element is responsible for the connection between the ring gear shaft of the first planetary gear set and the planetary carrier shaft of the first planetary gear set, and the third switching element controls the connection between the planetary carrier shaft of the first planetary gear set and other components. The shift sleeve slides axially according to different working conditions to quickly switch between gears.

[0043] It can be seen that by designing the switching element group as the first switching element, the second switching element and the third switching element, and realizing the gear switching by the engagement of the shift sleeve with these switching elements, the gear shifting efficiency and the flexibility of the transmission system are effectively improved. The coordinated work of multiple switching elements ensures the precise switching between each gear, making the power transmission smoother and more efficient. Compared with the traditional complex shifting system, this design simplifies the mechanical structure, reduces the manufacturing cost, and improves the reliability and durability of the system. Overall, this application optimizes the operating experience of the electric drive axle while improving the power performance, and meets the power output requirements under different working conditions.

[0044] As a possible implementation method, the gear mode of the coaxial electric drive axle includes a first gear mode, a second gear mode and a third gear mode. In the first gear mode, the shift sleeve interlocks the first switching element and the second switching element, in the second gear mode, the shift sleeve interlocks the second switching element and the third switching element, and in the third gear mode, the shift sleeve interlocks the second switching element.

[0045] Specifically, when the vehicle is in the first gear mode, the shift sleeve in the shift mechanism interlocks the first switching element and the second switching element, that is, the electric drive axle housing shaft and the ring gear shaft of the first planetary gear set are fixedly connected, so that the two shafts rotate synchronously. The first motor is used as a power source, and its power is input into the first planetary gear set through the sun gear shaft of the first planetary gear set. Here, the sun gear shaft of the first planetary gear set is used as the input shaft of the first planetary gear set and is directly connected to the first motor. The rotation of the first motor will be directly converted into power transmission in the gear set. In the first planetary gear set, when the sun gear shaft rotates, it drives the planetary gear to rotate around its own axis. At the same time, the planetary gear transmits power to the planetary carrier shaft under the interaction with the ring gear shaft and the planetary carrier shaft. Since the electric drive axle housing shaft is fixedly connected to the ring gear shaft of the first planetary gear set, the rotation of the ring gear shaft is limited by the housing shaft, so the first planetary gear set will show a larger reduction ratio at this time, that is, the input angular velocity of the sun gear shaft is much greater than the output angular velocity of the planetary carrier shaft, so as to increase the torque output. The rotation of the planetary carrier shaft of the first planetary gear set transmits power to the second motor. The second motor is fixedly connected to the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set. Therefore, the rotation of the planetary carrier shaft of the first planetary gear set directly becomes the power input of the second motor. After receiving the input of the second motor, the sun gear shaft of the second planetary gear set transmits power to the second planetary gear set, and the power output is further adjusted by the reduction ratio of the second planetary gear set. The planetary carrier shaft transmits the output of the second planetary gear set to the differential to balance the speed of the two wheels to meet the needs of the vehicle when turning. The differential receives the output of the second planetary gear set and distributes its power evenly to the left and right wheels, but allows the two wheels to have different speeds when turning. Subsequently, the power is reduced in the last stage through the third planetary gear set and the fourth planetary gear set to increase the torque to meet the power requirements of the vehicle, especially the heavy commercial vehicle, at low speed or complex road conditions. Among them, the third planetary gear set and the fourth planetary gear set are planetary gear sets of wheel-side reducers, which are two identical NGW planetary gear sets.

[0046] After continuous deceleration and torque increase of the first planetary gear set, the second planetary gear set and the third planetary gear set, the final power is distributed through the differential and output by the left and right wheels to push the vehicle forward. In the first gear mode, due to the multi-stage deceleration, the vehicle can obtain higher torque, which is suitable for working conditions that require greater traction such as starting or climbing. Through this series of dynamic interlocking and power transmission, the new coaxial electric drive axle in the first gear mode can efficiently and reliably convert the power of the motor into the rotation of the wheels, and adjust the torque and speed according to the actual needs of the vehicle, providing strong power support for the vehicle's low-speed driving or starting.

[0047] Specifically, when the vehicle is in the second gear mode, the shift sleeve in the shift mechanism interlocks the second switching element and the third switching element, that is, the ring gear shaft of the first planetary gear set and the planetary carrier shaft of the first planetary gear set are fixedly connected, allowing power to be directly transmitted from the ring gear shaft of the first planetary gear set to the planetary carrier shaft of the first planetary gear set without generating additional deceleration through the first planetary gear set. The first motor is used as a power source, and its power is input into the first planetary gear set through the sun gear shaft of the first planetary gear set. Unlike the first gear, at this time, since the ring gear shaft of the first planetary gear set is fixedly connected to the planetary carrier shaft of the first planetary gear set, it means that the rotation speeds of the ring gear shaft and the planetary carrier shaft are equal, so the first planetary gear set does not actually produce any deceleration effect, and its speed ratio is 1:1. In the second gear mode, the speed ratio of the first planetary gear set is 1, which means that the power output by the first motor is directly and non-deceleratedly transmitted to the planetary carrier shaft of the first planetary gear set, and then directly transmitted to the planetary carrier shaft of the first planetary gear set fixedly connected thereto. This direct transmission mechanism can reduce energy loss in the transmission process and improve the overall transmission efficiency under conditions where high torque is not required. The planetary carrier shaft of the second planetary gear set receives direct power from the first planetary gear set, and the power of the second motor is input by the sun gear shaft of the second planetary gear set. After receiving the direct power of the first motor, the participation of the second motor can further adjust the overall output of the system to adapt to the driving needs of the vehicle in the second gear mode. After the sun gear shaft of the second planetary gear set receives the input of the second motor, the power will be further adjusted by the reduction ratio of the second planetary gear set, and output to the differential by the planetary carrier shaft of the second planetary gear set. This stage of reduction is to adapt to the speed requirements of the vehicle in the second gear mode while maintaining a certain torque. The differential receives the power output of the second planetary gear set and distributes it evenly to the left and right wheels, but allows the two wheels to have different speeds when turning to adapt to the driving state of the vehicle. Subsequently, the power is reduced by the third planetary gear set for the final stage to increase the torque to ensure that the vehicle can still obtain sufficient traction when needed.

[0048] After further deceleration through the second, third and fourth planetary gear sets, the power is finally output through the left and right wheels to propel the vehicle forward. In the second gear mode, due to the reduction of the deceleration effect of the first planetary gear set, the vehicle can travel at medium and high speeds in a more efficient manner, while obtaining the necessary torque through the deceleration of the second, third and fourth planetary gear sets when necessary.

[0049] Specifically, when the vehicle needs to switch to the third gear mode, that is, neutral gear, the sleeve in the shift mechanism only interlocks the second switching element, but not the first switching element and the third switching element, which means that the ring gear shaft of the first planetary gear set is fixed or connected to a component directly connected thereto, while the housing shaft of the coaxial electric drive axle and the planetary carrier shaft of the first planetary gear set are in a free constraint state, that is, they can rotate freely without being constrained by the shift sleeve or other components. In the third gear mode, although the first motor can operate, since there is no effective mechanical connection between the housing shaft of the coaxial electric drive axle and the planetary carrier shaft of the first planetary gear set, the power of the first motor cannot be transmitted to the second planetary gear set or the second motor through the first planetary gear set. Therefore, even if the first motor generates power, the power will not be transmitted to the wheels, and the vehicle will not move as a result. Since the planetary carrier shaft of the first planetary gear set is in a free constraint state, the second motor can work independently. However, in the third gear mode, the second motor is usually not activated because there is no power to be transmitted to the wheels, and the operation of the second motor will not affect the driving state of the vehicle.

[0050] In summary, in the third gear mode (i.e. neutral), the power flow path of the system is designed to be closed. The power of the first motor cannot be transmitted to the differential or the third planetary gear set and the fourth planetary gear set through the first planetary gear set and the second planetary gear set, and then cannot reach the wheels, which means that the vehicle will not be affected by the electric drive force and move even if the motor is running. In the third gear mode (i.e. neutral), the vehicle can be safely stationary, even on a slope, because there is no power flow through the transmission system. The key to the design of the third gear mode is to allow the motor to run without driving the vehicle, which is very important for vehicle start preparation, system inspection, and scenarios where the motor needs to run but the vehicle does not move (such as motor testing during charging). Through precise control of the shift sleeve, the effective separation of the motor and the transmission system can be achieved, ensuring that the vehicle can be safely stationary when needed.

[0051] As a possible implementation method, the driving modes of the coaxial electric drive bridge include a dual-motor driving mode and a single-motor driving mode, wherein the dual-motor driving mode is that the first motor and the second motor work simultaneously, and the single-motor driving mode is that the first motor works alone or the second motor works alone. In the dual-motor driving mode, the first motor is in the first gear mode or the second gear mode and the second motor is a fixed speed ratio. In the single-motor driving mode, the first motor is in the first gear mode or the second gear mode and the second motor does not work, or the first motor does not work and the second motor is a fixed speed ratio.

[0052] Specifically, the driving modes of the coaxial electric drive axle include dual-motor driving mode and single-motor driving mode. In the dual-motor driving mode, the first motor and the second motor work at the same time, which can provide higher power output and better performance according to different working conditions. Furthermore, the first motor can be switched to the first gear mode or the second gear mode as needed, and the second motor is a fixed speed ratio, responsible for providing stable power output. In the single-motor driving mode, the first motor can be selected to work alone or the second motor can be selected to work alone. Specifically, the first motor can work alone in the first gear mode or the second gear mode, and the second motor does not work; or in another single-motor driving mode, the first motor does not work, and the second motor runs at a fixed speed ratio to provide stable power.

[0053] It can be seen that by designing the dual-motor drive mode and the single-motor drive mode, the coaxial electric drive axle can be flexibly switched under different working conditions to provide the best power output. In the dual-motor drive mode, the first motor and the second motor work at the same time, which can meet high power requirements and improve power performance; while in the single-motor drive mode, by using a single motor, it not only reduces energy consumption but also optimizes battery life. This design enables the electric drive axle to achieve a good balance between efficient energy utilization and performance, while simplifying the control logic, reducing system complexity, and ensuring the efficiency, economy and reliability of the system.

[0054] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the coaxial electric drive bridge of the present application will be described in detail below in conjunction with specific embodiments.

[0055] The present application provides a coaxial electric drive axle, which can realize coaxial two-gear power output. The architecture is an asymmetric scheme, using the internal space of the bridge tube to arrange the shift mechanism on one side and the differential on the other side. In addition, the first motor is a two-gear motor, the second motor is a single-gear motor, and the reducer is composed of four NGW planetary gear sets, namely, the first planetary gear set, the second planetary gear set, the third planetary gear set and the fourth planetary gear set, wherein the wheel-side reducer is two identical NGW planetary gear sets, named the third planetary gear set and the fourth planetary gear set. Specifically, the first planetary gear set is responsible for transmitting power, and the gear shifting meshing claws and different switching elements are designed, that is, the housing shaft of the coaxial electric drive axle, the ring gear shaft of the first planetary gear set and the planetary carrier shaft of the first planetary gear set are interlocked in different combinations to realize gear shifting. The first motor inputs power through the sun gear shaft of the first planetary gear set, and the second motor outputs power through the planetary carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set. The shift sleeve is meshed with the switching element, and the gear can be switched according to demand to optimize the power output path.

[0056] The architecture is designed as a three-gear coaxial electric drive axle system, which can switch gears according to working conditions to achieve efficient power transmission. The specific gear settings are: first gear mode (first gear), first gear mode (second gear) and first gear mode (neutral gear). The function of each gear is realized by interlocking different switching elements with the sliding sleeve in the shift mechanism. The realization of different gear functions of this architecture is shown in Table 1.

[0057] Table 1 Function realization of different gears

[0058] Gear First switching element The second switching element The third switching element First gear mode √ √ × Second gear mode × √ √ Third gear mode × √ ×

[0059] In the first gear mode, the sliding sleeve of the shift mechanism interlocks the first switching element and the second switching element, so that the housing shaft of the coaxial electric drive axle and the ring gear shaft of the first planetary gear set are fixedly connected, ensuring the stability of the power transmission path. The power of the first motor is input to the sun gear shaft of the first planetary gear set through its output shaft. The first motor, as the main power source, drives the entire power transmission system. The power of the first motor is transmitted to the second motor through the planetary carrier shaft of the first planetary gear set. At this time, the first planetary gear set acts as a bridge for power transmission, ensuring efficient linkage between motors. The second motor receives power from the first motor, inputs power to the second planetary gear set through the sun gear shaft of the second planetary gear set, and the planetary carrier shaft of the second planetary gear set outputs power to the differential. The differential further transmits the power of the second motor to the left and right wheels, and performs the final level of deceleration through the third planetary gear set and the fourth planetary gear set, ensuring that the power is accurately transmitted to the wheels and drives the vehicle to travel. At this point, the power flow transmission in the first gear is completed, providing stable power output to adapt to working conditions such as starting and low-speed driving.

[0060] In the second gear mode, the sliding sleeve of the shift mechanism interlocks the second switching element and the third switching element, so that the ring gear shaft of the first planetary gear set and the planetary carrier shaft of the first planetary gear set are fixedly connected, forming a direct transmission path. The power of the first motor is input to the sun gear shaft of the first planetary gear set through its output shaft, and the speed ratio of the first planetary gear set is 1, which means that the first planetary gear set no longer performs deceleration. The power of the first motor is directly transmitted to the second motor through the first planetary gear set. The power of the second motor is input from the sun gear shaft of the second planetary gear set and output through the planetary carrier shaft of the second planetary gear set. At this time, the input power of the second motor is transmitted to the differential through the second planetary gear set. After receiving the power of the second motor, the differential transmits it to the left and right wheels. The power is decelerated at the final level through the third planetary gear set and the fourth planetary gear set, and drives the vehicle to travel. In the second gear mode, since the speed ratio of the first planetary gear set is 1, the first motor directly outputs power without deceleration, which can provide higher transmission efficiency and is suitable for stable output at medium speed or higher speed.

[0061] In the third gear mode, the sleeve of the shift mechanism interlocks the second switching element, that is, the ring gear shaft of the first planetary gear set is fixed, while the housing shaft of the coaxial electric drive axle and the planetary carrier shaft of the first planetary gear set are in a free constraint state, and the output shaft of the first motor is disconnected from the power transmission path, so the power of the first motor is no longer transmitted to the first planetary gear set. The first motor does not participate in power transmission at this time and is in a neutral state. Therefore, the power flow of the vehicle is completely interrupted and the vehicle is no longer driven by the motor. The neutral state is mainly used when the vehicle is parked or stopped, avoiding unnecessary energy consumption caused by the continuous operation of the motor, and also helps to reduce the wear of vehicle components.

[0062] The electric drive axle can adapt to different working conditions by switching between dual-motor drive mode and single-motor drive mode, and further optimize energy transmission through different gear settings. In each drive mode, it can be further subdivided into 5 different drive modes according to the division of different gears and whether the second motor is running. The drive mode of the electric drive axle is shown in Table 2. At the start, the first motor is in the first gear. As the motor speed is adjusted, the first motor gradually turns to neutral gear, and then the second motor enters the second gear. This switching process can achieve smooth power output at the beginning of vehicle driving. For light load conditions, the system can choose to be driven by only the first motor or the second motor alone, thereby improving economy and reducing energy consumption; while under heavy load conditions, the first motor and the second motor can work at the same time to provide sufficient power output and ensure the power performance of the vehicle.

[0063] Table 2 Driving mode of coaxial electric drive bridge

[0064]

[0065] When the driver releases the accelerator or brakes during driving, the vehicle's kinetic energy can be converted into electrical energy through the brake energy recovery system and stored in the battery. This process effectively utilizes the energy generated during braking, which is then converted back into driving energy to provide continuous power output for the vehicle. Through this design, the electric drive axle can improve energy utilization efficiency, reduce energy waste, and achieve more efficient power system management, while taking into account both power and economy.

[0066] In summary, the coaxial electric drive axle of the present application reduces the overall dimensions and improves the overall integration and space utilization by adopting a coaxial architecture. This design enables the system to be arranged more compactly, thereby saving space for the entire vehicle, freeing up more space for other components of the vehicle, and enhancing the design flexibility of the entire vehicle. In addition, the electric drive axle supports flexible selection of multiple drive modes such as dual-motor drive or single-motor drive according to different working conditions. This switching mechanism enables the electric drive axle to optimize energy efficiency according to actual needs while ensuring power, balancing performance and economy, thereby greatly improving the vehicle's power system efficiency and energy efficiency.

[0067] According to the wheel torque requirements and motor parameters, other coaxial electric drive axle application case architecture diagrams are as follows Figure 2 to Figure 5 As shown. Different architecture designs can be optimized and adjusted according to specific vehicle application requirements to ensure that while providing sufficient power, the efficiency and performance requirements of the vehicle under different working conditions are met. By rationally configuring core components such as motors, gear sets and differentials, the stability and adaptability of the drive system can be effectively improved, thereby better serving various types of new energy vehicle applications.

[0068] Application Case 1

[0069] like Figure 2 As shown, the coaxial electric drive axle includes: a first motor 10, a second motor 20, a first planetary gear set 01, a second planetary gear set 02, a third planetary gear set 03, a fourth planetary gear set 04, a differential 30 and a shift mechanism 40, the first planetary gear set includes a switching element group, the shift mechanism includes a shift sleeve, the switching element group includes a first switching element 60, a second switching element 70 and a third switching element 80, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planetary carrier shaft of the first planetary gear set, and the shift sleeve is engaged with one or more of the first switching element, the second switching element and the third switching element by axial movement to switch gears, so as to switch the power flow path, and finally transmit power to the wheels 50.

[0070] Application Case 2

[0071] like Figure 3As shown, the coaxial electric drive axle includes: a first motor 10, a second motor 20, a first planetary gear set 01, a second planetary gear set 02, a third planetary gear set 03, a differential 30 and a shift mechanism 40, the first planetary gear set includes a switching element group, the shift mechanism includes a shift sleeve, the switching element group includes a first switching element 60, a second switching element 70 and a third switching element 80, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planet carrier shaft of the first planetary gear set, and the shift sleeve is engaged with one or more of the first switching element, the second switching element and the third switching element by axial movement to switch gears, so as to switch the power flow path, and finally transmit power to the wheels 50.

[0072] Application Case 3

[0073] like Figure 4 As shown, the coaxial electric drive axle includes: a first motor 10, a second motor 20, a first planetary gear set 01, a second planetary gear set 02, a third planetary gear set 03, a fourth planetary gear set 04, a differential 30 and a shift mechanism 40, the first planetary gear set includes a switching element group, the shift mechanism includes a shift sleeve, the switching element group includes a first switching element 60, a second switching element 70 and a third switching element 80, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planetary carrier shaft of the first planetary gear set, and the shift sleeve is engaged with one or more of the first switching element, the second switching element and the third switching element by axial movement to switch gears, so as to switch the power flow path, and finally transmit power to the wheels 50.

[0074] Application Case 4

[0075] like Figure 5 As shown, the coaxial electric drive axle includes: a first motor 10, a second motor 20, a first planetary gear set 01, a second planetary gear set 02, a third planetary gear set 03, a differential 30 and a shift mechanism 40, the first planetary gear set includes a switching element group, the shift mechanism includes a shift sleeve, the switching element group includes a first switching element 60, a second switching element 70 and a third switching element 80, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planet carrier shaft of the first planetary gear set, and the shift sleeve is engaged with one or more of the first switching element, the second switching element and the third switching element by axial movement to switch gears, so as to switch the power flow path, and finally transmit power to the wheels 50.

[0076] In order to achieve the above object, according to one aspect of the present application, a control method for a coaxial electric drive bridge is provided. Figure 6 FIG. 1 is a flow chart of a control method of a coaxial electric drive bridge according to an embodiment of the present application. Figure 6 As shown, the following steps are included:

[0077] Step S601, obtaining the operating condition of the coaxial electric drive axle;

[0078] Specifically, sensors or control systems collect the current vehicle operating status and working condition information, such as vehicle speed, load, driver operation (such as throttle or brake control) and other data. These data can accurately reflect the real-time working environment of the vehicle and provide a basis for subsequent gear selection and shift control. By obtaining working condition information in real time, it is ensured that the electric drive axle can dynamically adjust the working mode according to different usage requirements.

[0079] Step S602, determining the gear mode of the coaxial electric drive axle according to the operating condition of the coaxial electric drive axle;

[0080] Specifically, the system analyzes the power transmission mode required by the current vehicle based on the operating condition information collected in step S601, thereby determining the most suitable gear mode. For example, at low speed or starting stage, the first gear mode may need to be selected to provide greater torque; while at high speed, the second gear mode is selected to provide higher vehicle speed and lower energy consumption. The purpose of this step is to ensure that the electric drive axle always operates in the most suitable working mode to optimize the performance of the vehicle.

[0081] Step S603: Based on the gear mode of the coaxial electric drive axle, control the shift sleeve to interlock at least part of the switching elements in the switching element group.

[0082] Specifically, according to the gear mode determined in step S602, the control system will instruct the shift sleeve in the shift mechanism to move axially, interlock the first switching element, the second switching element, and the third switching element in the switching element group, so that the housing shaft of the coaxial electric drive axle, the ring gear shaft of the first planetary gear set, and the planetary carrier shaft of the first planetary gear set are connected in different combinations to complete the gear switching. The shift mechanism can accurately control the power transmission path according to different gear modes, thereby achieving accurate gear switching and meeting the power requirements under different working conditions.

[0083] By applying the technical solution of the present application, the control method can accurately adjust the gear mode of the coaxial electric drive axle according to the real-time working conditions, thereby achieving more efficient and intelligent power control. By automatically selecting and switching gears according to the actual operating needs of the vehicle, the performance and energy efficiency of the vehicle can be optimized under different working conditions such as starting, acceleration, deceleration and high-speed driving. In addition, the method reduces human intervention through intelligent control, improves the smoothness and comfort of driving, and effectively improves the overall efficiency and reliability of the electric drive axle system.

[0084] As a possible implementation method, the gear mode of the coaxial electric drive axle is determined according to the operating condition of the coaxial electric drive axle, including:

[0085] If the operating condition of the coaxial electric drive axle is the first operating condition, determining the gear mode of the coaxial electric drive axle to be the first gear mode;

[0086] Specifically, if the operating condition of the coaxial electric drive axle is the first operating condition (such as low-speed starting or high-load conditions), the system will select the first gear mode to provide a larger torque output. This mode is suitable for scenarios that require a larger starting torque, such as starting, climbing, etc., to ensure that the vehicle can start smoothly and overcome a large load.

[0087] If the operating condition of the coaxial electric drive axle is the second operating condition, determining the gear mode of the coaxial electric drive axle to be the second gear mode;

[0088] Specifically, if the coaxial electric drive axle is in the second operating condition (such as normal driving or medium load condition), the system will select the second gear mode to balance power output and energy efficiency and provide appropriate vehicle speed and power output. This mode is suitable for normal driving conditions, ensuring that the vehicle achieves higher driving efficiency without sacrificing power.

[0089] If the operating condition of the coaxial electric drive axle is the third operating condition, determining the gear mode of the coaxial electric drive axle to be the third gear mode;

[0090] Specifically, if the coaxial electric drive axle is in the third operating condition (such as high-speed driving or low-load conditions), the system will select the third gear mode to provide the highest vehicle speed and the lowest energy consumption. In this mode, the vehicle has the highest power transmission efficiency and is suitable for long-term high-speed cruising.

[0091] Based on the gear mode of the coaxial electric drive axle, controlling the shift sleeve to interlock at least part of the switching elements in the switching element group includes:

[0092] If the gear mode of the coaxial electric drive axle is the first gear mode, the shift sleeve is controlled to interlock the first switching element and the second switching element in the switching element group;

[0093] If the gear mode of the coaxial electric drive axle is the second gear mode, the shift sleeve is controlled to interlock the second switching element and the third switching element in the switching element group;

[0094] If the gear mode of the coaxial electric drive axle is the third gear mode, the shift sleeve is controlled to interlock the second switching element in the switching element group.

[0095] Specifically, according to the selected gear mode, the system will control the interlocking of different switching elements in the switching element group through the shift sleeve. In the first gear mode, the shift sleeve interlocks the first switching element with the second switching element to ensure that the power of the motor flows according to the first gear mode; in the second gear mode, the shift sleeve interlocks the second switching element with the third switching element to ensure that the power is transmitted to the second motor and the power output is completed through the reducer and other components; in the third gear mode, the shift sleeve interlocks the second switching element to ensure that the second motor runs at a fixed speed ratio.

[0096] In summary, this control method ensures that the electric drive axle system can provide optimal power output and energy efficiency under different working conditions by dynamically adjusting the gear mode according to the actual operating conditions of the coaxial electric drive axle. When starting and driving at low speeds, the system automatically selects a lower gear mode to provide sufficient torque to ensure smooth starting of the vehicle; during normal driving and high-speed driving, the system switches to a suitable gear mode to improve driving efficiency and reduce energy consumption. In addition, intelligent gear switching not only improves the vehicle's power response, but also optimizes energy use, improves vehicle performance and driving experience, and avoids power waste or reduced efficiency due to gear mismatch, thereby achieving a balance between power and economy.

[0097] According to another aspect of the present application, a coaxial electric drive bridge system is provided, comprising: any one of the above-mentioned coaxial electric drive bridges; and a controller, communicating with the above-mentioned coaxial electric drive bridge, for executing any one of the above-mentioned coaxial electric drive bridge control methods.

[0098] According to another aspect of the present application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute any one of the control methods for a coaxial electric drive axle.

[0099] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0100] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0101] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0102] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0103] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0104] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0105] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0106] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0107] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0108] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0109] 1) A coaxial electric drive bridge is provided. Due to the coaxial architecture design, the output shafts of the first motor and the second motor are connected to multiple planetary gear sets. The compact layout reduces the occupancy of the external space and improves the overall integration of the system. The electric drive bridge realizes the power output of two gears through the shift mechanism, and can flexibly switch gears according to different working conditions. The meshing design of the shift sleeve and the switching element group enables the power flow path to be precisely controlled, thereby providing more efficient power transmission and a more optimized driving experience under different driving conditions. For example, when starting, a low speed gear is used to provide a higher starting torque, and when driving at high speed, it is switched to the efficient second gear to achieve lower energy consumption and smoother driving. Through the ingenious design of the four planetary gear sets, especially in the switching element group of the first planetary gear set, seamless switching and precise power transmission can be achieved. The electric bridge supports flexible switching between dual-motor and single-motor drive modes. While ensuring power, it can also optimize energy efficiency according to load conditions to achieve lower energy consumption. Thereby solving the problem that the existing coaxial electric drive bridge is difficult to apply to the complex and changeable working conditions of new energy vehicles.

[0110] 2) A control method for a coaxial electric drive axle is provided, which can accurately adjust the gear mode of the coaxial electric drive axle according to the real-time working conditions, thereby achieving more efficient and intelligent power control. By automatically selecting and switching gears according to the actual operating needs of the vehicle, the performance and energy efficiency of the vehicle can be optimized under different working conditions such as starting, acceleration, deceleration and high-speed driving. In addition, the method reduces human intervention through intelligent control, improves the smoothness and comfort of driving, and effectively improves the overall efficiency and reliability of the electric drive axle system. This solves the problem that the existing coaxial electric drive axle is difficult to apply to the complex and changeable working conditions of new energy vehicles.

[0111] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coaxial electric drive bridge, characterized in that: include: a first motor, a second motor, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a differential and a shift mechanism, wherein the first planetary gear set includes a switching element set, and the shift mechanism includes a shift sleeve, Among them, the output shaft of the first motor is connected to the sun gear shaft of the first planetary gear set, the input shaft and the output shaft of the second motor are respectively connected to the planet carrier shaft of the first planetary gear set and the sun gear shaft of the second planetary gear set, the input shaft of the differential is connected to the planet carrier shaft of the second planetary gear set, the two output shafts of the differential are respectively connected to the input shaft of the third planetary gear set and the input shaft of the fourth planetary gear set, the two output half shafts of the differential are respectively connected to the left and right wheels, and the shift sleeve is engaged with the switching element group through axial movement to switch the power flow path.

2. The coaxial electric drive bridge according to claim 1, characterized in that: The shift mechanism and the differential are asymmetrically distributed on both sides of the coaxial electric drive bridge, and the rotation center line of the input shaft of the first motor and the rotation center line of the input shaft of the second motor coincide with the rotation center line of the output half shaft of the electric drive bridge.

3. The coaxial electric drive bridge according to claim 1, characterized in that: The first motor is a dual-speed motor, and the second motor is a single-speed motor.

4. The coaxial electric drive bridge according to claim 1, characterized in that: The switching element group includes a first switching element, a second switching element and a third switching element, the first switching element is connected to the housing shaft of the coaxial electric drive axle, the second switching element is connected to the ring gear shaft of the first planetary gear set, and the third switching element is connected to the planetary carrier shaft of the first planetary gear set. The shift sleeve engages with one or more of the first switching element, the second switching element and the third switching element through axial movement to switch gears.

5. The coaxial electric drive bridge according to claim 4, characterized in that: The gear modes of the coaxial electric drive axle include a first gear mode, a second gear mode and a third gear mode. In the first gear mode, the shift sleeve interlocks the first switching element and the second switching element, in the second gear mode, the shift sleeve interlocks the second switching element and the third switching element, and in the third gear mode, the shift sleeve interlocks the second switching element.

6. The coaxial electric drive bridge according to claim 5, characterized in that: The driving modes of the coaxial electric drive bridge include a dual-motor driving mode and a single-motor driving mode. Among them, the dual-motor drive mode is that the first motor and the second motor work simultaneously, and the single-motor drive mode is that the first motor works alone or the second motor works alone. In the dual-motor drive mode, the first motor is in the first gear mode or the second gear mode and the second motor is a fixed speed ratio. In the single-motor drive mode, the first motor is in the first gear mode or the second gear mode and the second motor does not work, or the first motor does not work and the second motor is a fixed speed ratio.

7. A control method for a coaxial electric drive bridge according to any one of claims 1 to 6, characterized in that: include: Obtain the operating conditions of the coaxial electric drive axle; Determining a gear mode of the coaxial electric drive axle according to the operating condition of the coaxial electric drive axle; Based on the gear mode of the coaxial electric drive axle, the shift sleeve is controlled to interlock at least part of the switching elements in the switching element group.

8. The method according to claim 7, characterized in that Determining the gear mode of the coaxial electric drive axle according to the operating condition of the coaxial electric drive axle includes: If the operating condition of the coaxial electric drive axle is the first operating condition, determining the gear mode of the coaxial electric drive axle to be the first gear mode; If the operating condition of the coaxial electric drive axle is the second operating condition, determining the gear mode of the coaxial electric drive axle to be the second gear mode; If the operating condition of the coaxial electric drive axle is the third operating condition, determining the gear mode of the coaxial electric drive axle to be the third gear mode; Based on the gear mode of the coaxial electric drive axle, controlling the shift sleeve to interlock at least part of the switching elements in the switching element group includes: If the gear mode of the coaxial electric drive axle is the first gear mode, controlling the shift sleeve to interlock the first switching element and the second switching element in the switching element group; If the gear mode of the coaxial electric drive axle is the second gear mode, controlling the shift sleeve to interlock the second switching element and the third switching element in the switching element group; If the gear mode of the coaxial electric drive axle is the third gear mode, the shift sleeve is controlled to interlock the second switching element in the switching element group.

9. A coaxial electric drive axle system, characterized in that: include: The coaxial electric drive axle according to any one of claims 1 to 6; A controller, communicating with the coaxial electric drive bridge, is used to execute the control method of the coaxial electric drive bridge according to claim 7 or 8.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the control method of the coaxial electric drive axle according to claim 7 or 8.

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