Electric drive system and four-wheel drive vehicle

Abstract

The invention provides an electric drive system and a four-wheel drive vehicle, the electric drive system comprises an engine, an input shaft, a first clutch, a first motor, a first intermediate shaft, a second clutch and a second motor, the input shaft is connected with the engine, the first clutch is arranged on the input shaft and is connected with the first motor and the second clutch through the first clutch, and the second clutch is arranged on the second intermediate shaft. The second clutch is arranged on the first intermediate shaft, the first intermediate shaft is connected with the first wheel end of the vehicle, and the second motor is connected with the second wheel end of the vehicle, so that the four-wheel-drive function, the front-wheel-drive function and the rear-wheel-drive function can be achieved only through the two motors and the two clutches, the size is reduced, and cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of vehicles, and mainly to an electric drive system and a four-wheel drive vehicle. Background Art

[0002] In existing four-wheel drive vehicles with electric drive systems, the electric drive systems generally include extended-range electric drive systems or plug-in electric drive systems.

[0003] The extended-range electric drive system utilizes a combination of the drive motor and the first motor, enabling only series mode, pure electric mode, parking mode, and energy recovery mode. During high-speed cruising, the vehicle's power requirements are low, but the engine cannot directly drive the vehicle. The engine still needs to drive the first motor to generate electricity, which is then directly or indirectly fed to the drive motor to propel the wheels. While the engine operates at its optimal efficiency point, reducing fuel consumption compared to a combustion engine, the power to the wheels suffers significant losses due to multiple conversions, making it a non-optimal operating point. Furthermore, relying solely on a single drive motor to power either the front or rear wheels doesn't fully utilize the vehicle's grip and achieve optimal power performance. Without all-wheel drive, the drive wheels are more susceptible to slipping on wet roads, increasing the likelihood of the vehicle spinning out or spinning out. Furthermore, achieving all-wheel drive requires the addition of an electric drive system to supplement this power requirement, which increases vehicle powertrain costs and complicates vehicle integration. Furthermore, the engine-less high-speed direct drive mode also presents technical challenges, such as higher fuel consumption.

[0004] The plug-in electric drive system uses a multi-speed electric drive system for the front wheel, and an electric drive system for the rear wheel, achieving a four-wheel drive architecture for the entire vehicle. This architecture can realize pure electric four-wheel drive and parallel four-wheel drive modes, and the engine direct drive mode has multiple gears to improve the fuel economy of the engine in direct drive mode. The plug-in hybrid vehicle equipped with this solution has a large battery capacity and sufficient battery capacity to achieve pure electric driving in most operating conditions. The engine only participates in driving under high-speed conditions or deep-feed conditions. The utilization rate of the engine using multiple gears is not high, and it brings technical reliability and user experience issues such as complex system structure, long assembly axial dimension, increased parts, high assembly cost, and poor shifting comfort. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide an electric drive system and a four-wheel drive vehicle, which can realize front and rear wheel drive of the vehicle and are small in size and low in cost.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] An electric drive system includes an engine, an input shaft, a first clutch, a first motor, a first intermediate shaft, a second clutch, a second motor and a power battery; the input shaft is connected to the engine; the first clutch includes a first coupling and a second coupling, the first coupling is fixedly connected to the input shaft, and the second coupling can be coupled to or separated from the first coupling; the first motor is transmission-connected to the second coupling; the first intermediate shaft is parallel to the input shaft and is used for transmission connection to the first wheel end; the second clutch includes a third coupling and a fourth coupling, the third coupling is fixedly connected to the first intermediate shaft, the fourth coupling is transmission-connected to the second coupling, and the fourth coupling is coupled to or separated from the third coupling; the second motor is used for transmission connection to the second wheel end; the power battery is electrically connected to the first motor and the second motor.

[0008] In some schemes of the present application, the second coupling member is rotationally connected to the input shaft, and when the second coupling member and the first coupling member are in a separated state, the second coupling member can rotate relative to the first coupling member, and the second coupling member is provided with an input driving gear; the fourth coupling member is rotationally connected to the first intermediate shaft, and when the fourth coupling member and the third coupling member are in a separated state, the fourth coupling member can rotate relative to the third coupling member, and the fourth coupling member is provided with a sixth gear, and the sixth gear is transmission-connected to the input driving gear.

[0009] In some schemes of the present application, the first coupling member is the first clutch outer hub, the second coupling member is the first clutch inner hub, the first clutch inner hub is arranged inside the first clutch outer hub, and the input driving gear is located axially outside the first clutch outer hub; a first gear is provided on the output shaft of the first motor, the first gear is engaged with the input driving gear, and the diameter of the first gear is smaller than that of the input driving gear.

[0010] In some embodiments of the present application, the input driving gear includes a first input driving gear and a second input driving gear, the first input driving gear and the second input driving gear are distributed along the axial direction of the input shaft, the first input driving gear is engaged with the first gear, and the second input driving gear is engaged with the sixth gear; the diameter of the second input driving gear is smaller than the diameter of the first input driving gear.

[0011] In some embodiments of the present application, the rotating shaft of the first motor is provided with a center hole, and the first clutch is located inside the center hole; the first coupling member is the first clutch inner hub, the second coupling member is the first clutch outer hub, the first clutch inner hub is provided inside the first clutch outer hub, the first clutch outer hub is fixedly connected to the rotating shaft of the first motor, and the input driving gear is located axially outside the first motor.

[0012] In some embodiments of the present application, the third coupling member is the second clutch inner hub, the fourth coupling member is the second clutch outer hub, the second clutch inner hub is arranged inside the second clutch outer hub, and the sixth gear is located axially outside the second clutch outer hub.

[0013] In some embodiments of the present application, a fifth gear is provided on the first intermediate shaft; the electric drive system also includes a first differential, the first differential includes a first differential driven gear, the first differential driven gear is engaged with the fifth gear, and the diameter of the first differential driven gear is larger than the diameter of the fifth gear.

[0014] In some embodiments of the present application, a second gear is provided on the output shaft of the second motor; the electric drive system also includes a transmission assembly and a second differential, the transmission assembly includes a second intermediate shaft, a third gear and a fourth gear, the third gear and the fourth gear are arranged at intervals on the second intermediate shaft, the third gear is engaged with the second gear, and the diameter of the third gear is larger than the diameter of the second gear; the second differential includes a second differential driven gear, the second differential driven gear is engaged with the fourth gear, and the diameter of the second differential driven gear is larger than the diameter of the fourth gear.

[0015] In some embodiments of the present application, the operating modes of the electric drive system include a parallel four-wheel drive mode, a pure electric four-wheel drive mode, an engine direct drive mode, a parallel two-wheel drive mode, a pure electric two-wheel drive mode, a series mode, a parking power generation mode, a single-motor energy recovery mode, and a dual-motor energy recovery mode, wherein: when the parallel four-wheel drive mode is running, the first clutch and the second clutch are both engaged, the engine and the second motor are working, the power of the engine is transmitted to the first wheel end through the first clutch, the second clutch and the first intermediate shaft, and the second motor drives the second wheel end; when the pure electric four-wheel drive mode is running, the first clutch is disengaged, the second clutch is engaged, the first motor and the second motor are working, the engine is not working, the power of the first motor is transmitted to the first wheel end through the second coupling member of the first clutch, the second clutch, and the first intermediate shaft, and the second motor drives the second wheel end; when the engine direct drive mode is running, the first clutch and the second clutch are both engaged, the engine is working, the first motor and the second motor are not working, and the power of the engine is transmitted to the first wheel end through the first clutch, the second clutch and the first intermediate shaft; When operating in the coupled two-wheel drive mode, the first clutch and the second clutch are both engaged, the engine is operating, and the second motor is not operating. Part of the power of the engine is transmitted to the first wheel end through the first clutch, the second clutch and the first intermediate shaft, and the other power drives the first motor to generate electricity through the first clutch; when operating in the pure electric two-wheel drive mode, the first clutch and the second clutch are both disengaged, the engine and the first motor are not operating, and the second motor drives the second wheel end; when operating in the series mode, the first clutch is engaged, the second clutch is disengaged, the engine drives the first motor to generate electricity, and the second motor drives the second wheel end to rotate; when operating in the parking power generation mode, the first clutch is engaged, the second clutch is disengaged, the second motor is not operating, and the engine drives the first motor to generate electricity; when operating in the single-motor energy recovery mode, the first clutch and the second clutch are both disengaged, and the first wheel end and the second wheel end drive the first motor and the second motor to generate electricity; when operating in the dual-motor energy recovery mode, the first clutch is disengaged and the second clutch is engaged, and the first wheel end and the second wheel end drive the first motor and the second motor to generate electricity.

[0016] A four-wheel drive vehicle comprises a vehicle body, an electric drive system, a first wheel end and a second wheel end, wherein the electric drive system is mounted on the vehicle body; the first wheel end is drivingly connected to a first intermediate shaft of the electric drive system; and the second wheel end is drivingly connected to the second motor.

[0017] Beneficial effects: The electric drive system of the present application includes an engine, an input shaft, a first clutch, a first motor, a first intermediate shaft, a second clutch and a second motor. The input shaft is connected to the engine, the first clutch is arranged on the input shaft, and is connected to the first motor and the second clutch through the first clutch, the second clutch is arranged on the first intermediate shaft, the first intermediate shaft is connected to the first wheel end of the vehicle, and the second motor is connected to the second wheel end of the vehicle, so that the four-wheel drive function, the front-wheel drive function and the rear-wheel drive function can be realized with only two motors and two clutches, which reduces the volume and reduces the cost.

[0018] The four-wheel drive vehicle of the present application includes the above-mentioned electric drive system, which can realize four-wheel drive function, front-wheel drive function and rear-wheel drive function, and reduces the volume and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the electric drive system of Example 1.

[0020] Figure 2 It is a structural diagram of the electric drive system when it is in parallel four-wheel drive mode.

[0021] Figure 3 It is a structural diagram of the electric drive system when it is in pure electric four-wheel drive mode.

[0022] Figure 4 It is a structural diagram of the electric drive system when it is in engine direct drive mode.

[0023] Figure 5 It is a structural diagram of the electric drive system when it is in parallel two-drive mode.

[0024] Figure 6 It is a structural diagram of the electric drive system when it is in pure electric two-wheel drive mode.

[0025] Figure 7 It is a structural diagram of the electric drive system in series mode.

[0026] Figure 8 It is a structural diagram of the electric drive system when it is in parking power generation mode.

[0027] Figure 9 It is a structural diagram of the electric drive system when it is in single-motor energy recovery mode.

[0028] Figure 10 It is a structural diagram of the electric drive system when it is in dual-motor energy recovery mode.

[0029] Figure 11 It is a structural diagram of the electric drive system of Example 2.

[0030] Figure 12 It is a structural diagram of the electric drive system of Example 3.

[0031] Explanation of the main component symbols: 11-engine; 12-input shaft; 13-first motor; 131-first gear; 14-first intermediate shaft; 141-fifth gear; 15-second motor; 151-second gear; 16-power battery; 17-torsional vibration damper; 2-first clutch; 21-first coupling; 22-second coupling; 23-input driving gear; 231-first input driving gear; 232-second input driving gear; 3-second clutch; 32-third coupling; 31-fourth coupling; 33-sixth gear; 4-first differential; 41-first differential driven gear; 5-transmission assembly; 51-second intermediate shaft; 52-third gear; 53-fourth gear; 6-second differential; 61-second differential driven gear; 71-first wheel end; 72-second wheel end. DETAILED DESCRIPTION

[0032] The present invention provides an electric drive system and a four-wheel drive vehicle. To make the objectives, technical solutions, and effects of the present invention more clear and explicit, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0034] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections, or mutual communication; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] See Figure 1A four-wheel drive vehicle includes a vehicle body, an electric drive system, a first wheel end 71 and a second wheel end 72. The electric drive system is installed on the vehicle body. The first wheel end 71 is transmission-connected to the first intermediate shaft 14 of the electric drive system, so that the first wheel end 71 can be driven by the engine 11 or the first motor 13, or the first wheel end 71 can be driven by the engine 11 and the first motor 13. The second wheel end 72 is transmission-connected to the second motor 15, so that the second wheel end 72 is driven by the second motor 15.

[0036] The second motor 15 is a drive motor, mainly used to drive the vehicle, but can also be used to generate electricity. The first motor 13 is a generator, mainly used to generate electricity, but can also be used to drive the vehicle, thereby maximizing the vehicle's power.

[0037] In the above description, one of the first wheel end 71 and the second wheel end 72 is located at the front end of the vehicle body, forming the front wheel of the vehicle, while the other is located at the rear end of the vehicle body, forming the rear wheel of the vehicle. In a preferred embodiment of the present application, the first wheel end 71 is the front wheel of the vehicle, and the second wheel end 72 is the rear wheel of the vehicle. For ease of understanding, the electric drive system will be described below using the example of the first wheel end 71 being the front wheel of the vehicle and the second wheel end 72 being the rear wheel of the vehicle.

[0038] See Figure 1 、 Figure 11 as well as Figure 12 The electric drive system of the present application includes an engine 11, an input shaft 12, a first clutch 2, a first motor 13, a first intermediate shaft 14, a second clutch 3, a second motor 15 and a power battery 16. The input shaft 12 is connected to the engine 11, and the first clutch 2 includes a first coupling member 21 and a second coupling member 22. The first coupling member 21 is fixedly connected to the input shaft 12, and the second coupling member 22 can be coupled to or separated from the first coupling member 21. The first motor 13 is transmission-connected to the second coupling member 22. When the second coupling member 22 is coupled to the first coupling member 21 (that is, the first clutch 2 is in a coupled state), the power of the engine 11 can be transmitted to the first motor 13 through the input shaft 12 and the first clutch 2 to drive the first motor 13 to generate electricity, thereby improving the endurance of the electric drive system. When the engine is started, the first motor 13 can also be controlled to rotate to assist in starting the engine 11.

[0039] The first intermediate shaft 14 is parallel to the input shaft 12 and is drivingly connected to the first wheel end 71. The second clutch 3 includes a third coupling member 32 and a fourth coupling member 31. The third coupling member 32 is fixedly connected to the first intermediate shaft 14, and the fourth coupling member 31 is drivingly connected to the second coupling member 22. That is, the fourth coupling member 31 and the first motor 13 are both drivingly connected to the second coupling member 22, so that the power of the first motor 13 can be transmitted to the third coupling member 32 via the fourth coupling member 31. When the third coupling member 32 and the fourth coupling member 31 are engaged (i.e., the second clutch 3 is in the engaged state), the power of the first motor 13 can drive the first wheel end 71 to rotate.

[0040] Similarly, when the first clutch 2 and the second clutch 3 are both in the engaged state, the power of the engine 11 can be transmitted to the first wheel end 71 through the input shaft 12, the first clutch 2, the second clutch 3 and the first intermediate shaft 14, so that the engine 11 directly drives the vehicle to move.

[0041] The power battery 16 is electrically connected to the first motor 13 and the second motor 15 so that when one or both of the first motor 13 and the second motor 15 are used to drive the vehicle, the power battery 16 can provide power to the first motor 13 and the second motor 15, and when one or both of the first motor 13 and the second motor 15 are used to generate electricity, the electricity generated by the first motor 13 and the second motor 15 can be stored in the power battery 16.

[0042] In the above description, the electric drive system includes an engine 11, two motors, and two clutches. By controlling the engine 11, the first motor 13, the second motor 15, the first clutch 2, and the second clutch 3, the vehicle can achieve four-wheel drive, front-wheel drive, and rear-wheel drive functions. Moreover, the two clutches form a first gear structure between the input shaft 12 and the first intermediate shaft 14, maximizing the quietness and comfort of pure electric driving. The engine can be used for driving only during high-speed cruising, thus achieving the best balance between economy and system cost. The first clutch 2 and the second clutch 3 are arranged on different shaft systems, so that the system space is compact and the axial dimension is short, which is conducive to reducing the assembly weight and improving the system power density.

[0043] Specifically, the engine 11 and the first motor 13, or both, jointly drive the first wheel end 71 to rotate, while the second motor 15 drives the second wheel end 72 to rotate, thereby providing the vehicle with four-wheel drive. This prevents the wheels from slipping on slippery roads, preventing the vehicle from spinning out or spinning out, improving the vehicle's overall adhesion, and enhancing its overall power and safety. When the engine 11 and the first motor 13, or both, jointly drive the first wheel end 71 to rotate, and the second motor 15 is not operating, the second wheel end 72 becomes a driven structure, thereby achieving the vehicle's front-wheel drive function. When the engine 11 and the first motor 13 are not operating, and the second motor 15 drives the second wheel end 72 to rotate, the first wheel end 71 becomes a driven structure, thereby achieving the vehicle's rear-wheel drive function.

[0044] The vehicle's four-wheel drive functions include parallel four-wheel drive mode and pure electric four-wheel drive mode.

[0045] See Figure 2-Figure 10 , the arrows in the figure indicate the direction of power transmission.

[0046] When the electric drive system is in parallel four-wheel drive mode, the first clutch 2 and the second clutch 3 are both engaged, the engine 11 and the second motor 15 are working, and the power of the engine 11 is transmitted to the first wheel end 71 through the first clutch 2, the second clutch 3 and the first intermediate shaft 14. The excess power of the engine 11 can drive the first motor 13 to generate electricity, and the second motor 15 drives the second wheel end 72 to rotate. When the vehicle enters high-speed acceleration or high-speed climbing conditions, the vehicle adopts the following parallel two-wheel drive mode, at which time the operating point of the engine 11 falls within the high-efficiency range. When there is acceleration and overtaking at high speed or high-speed slope changes that require higher power, the second motor 15 intervenes and participates in the drive according to demand, so that the vehicle enters parallel four-wheel drive mode and provides greater driving force.

[0047] When the electric drive system is in pure electric four-wheel drive mode, the first clutch 2 is disengaged and the second clutch 3 is engaged, and the first motor 13 and the second motor 15 are in operation. The power of the first motor 13 is transmitted to the first wheel end 71 through the second coupling member 22 of the first clutch 2, the second clutch 3, and the first intermediate shaft 14. The second motor 15 then drives the second wheel end 72. When the power battery 16 has a high SOS (SOS refers to the remaining charge of the power battery 16), when the accelerator is pressed deeply at low and medium speeds or when overtaking at high speed, the pure electric four-wheel drive mode can be selected according to the power demand to provide a faster power response and a more dynamic acceleration.

[0048] The engine 11 and the first motor 13, or both, drive the first wheel end 71 to rotate, while the second motor 15 is not in operation, thus forming the front-wheel drive function of the vehicle. The front-wheel drive function of the vehicle includes an engine direct drive mode and a parallel two-wheel drive mode.

[0049] When the electric drive system is in the engine direct drive mode, the first clutch 2 and the second clutch 3 are both engaged, the engine 11 is working, the first motor 13 and the second motor 15 are not working, and the power of the engine 11 is transmitted to the first wheel end 71 through the first clutch 2, the second clutch 3 and the first intermediate shaft 14. When the vehicle enters a high-speed cruising condition, in order to optimize the energy consumption of the entire vehicle, the control strategy gives priority to the direct drive of the engine 11. At this time, the operating point of the engine 11 falls within the high-efficiency range, realizing the optimal transmission path of the power energy flow of the entire vehicle, which is conducive to reducing the energy consumption of the entire vehicle. In addition, the power energy of the engine 11 does not need to be converted into electrical energy through the first motor 13 first, and then converted into power to drive the vehicle through the second motor 15, avoiding the large loss of the power energy of the engine 11 due to multiple conversions.

[0050] When the electric drive system is in parallel two-wheel drive mode, the first clutch 2 and the second clutch 3 are both engaged, the engine 11 is operating, and the second motor 15 is not operating. Part of the power of the engine 11 is transmitted to the first wheel end 71 through the first clutch 2, the second clutch 3, and the first intermediate shaft 14, and the remaining power drives the first motor 13 to generate electricity through the first clutch 2. In the engine direct drive mode, if there is excess power after the engine 11 directly drives the wheels, the system switches to parallel two-wheel drive mode. The excess power of the engine 11 is used to drive the first motor 13 to generate electricity, and the electricity is stored in the power battery 16, thereby reducing power loss of the engine 11.

[0051] When the second motor 15 drives the second wheel 72 and neither the engine 11 nor the first motor 13 drives the first wheel 71, the vehicle's rear-wheel drive function is realized. The vehicle's rear-wheel drive function includes a pure electric two-wheel drive mode and a series mode (also known as an extended-range mode).

[0052] When the electric drive system is in pure electric two-wheel drive mode, the first clutch 2 and the second clutch 3 are both disengaged, the engine 11 and the first motor 13 are both inoperative, and the second motor 15 drives the second wheel end 72. In pure electric two-wheel drive mode, the first clutch 2 and the second clutch 3 are both disengaged, and only the first differential 4 and the intermediate shaft 14 rotate in counter-rotation with the vehicle speed, reducing the drag force of the vehicle, reducing the power loss of the second motor 15, and improving system efficiency.

[0053] When the electric drive system is in series mode, the first clutch 2 is engaged, the second clutch 3 is disengaged, the engine 11 drives the first motor 13 to generate electricity, and the second motor 15 drives the second wheel end 72 to rotate, wherein the electricity generated by the first motor 13 can be used to operate the second motor 15. When the battery is low SOS, the engine 11 starts the engine 11 by sliding the first motor 13 against the first clutch 2, and after the engine 11 starts, the first clutch 2 is engaged, and the power of the engine 11 drives the first motor 13 through the first clutch 2 to generate electricity to charge the power battery 16 or the electricity is supplied to the second motor 15 through the PDU power system components (i.e., the vehicle high-voltage distribution box). When the vehicle is in this working mode, only the first differential 4 and the intermediate shaft 14 rotate in the opposite direction of the vehicle speed, which reduces the drag force of the vehicle movement, reduces the power loss of the second motor 15, and improves the system efficiency.

[0054] In addition, the vehicle can also achieve parking power generation mode, single motor energy recovery mode and dual motor energy recovery mode.

[0055] When the electric drive system is in parking power generation mode, the first clutch 2 is engaged, the second clutch 3 is disengaged, the second motor 15 is not working, and the engine 11 drives the first motor 13 to generate electricity. When the vehicle's power battery SOS is low or the engine 11 is started at low temperature, the engine 11 is started and the first clutch 2 is engaged, so that the engine 11 drives the first motor 13 to generate electricity, converting the kinetic energy of the engine 11 into electricity for the power battery 16. Starting the engine 11 at low temperature means starting the engine 11 first when the vehicle is in a low temperature state and the vehicle is in a parked state, so that the engine 11 works and generates heat, thereby quickly heating the engine 11 to the optimal operating temperature, which is referred to as a heat engine.

[0056] When the electric drive system is in single-motor energy recovery mode, the first clutch 2 and the second clutch 3 are both disengaged, and the second wheel end 72 drives the second motor 15 to generate electricity. When the electric drive system is in dual-motor energy recovery mode, the first clutch 2 is disengaged and the second clutch 3 is engaged, and the first wheel end 71 and the second wheel end 72 respectively drive the first motor 13 and the second motor 15 to generate electricity.

[0057] When the vehicle requires low braking energy, it switches to single-motor energy recovery mode, and the second motor 15 converts part of the vehicle's kinetic energy into electricity for the power battery 16. When the vehicle requires high braking energy, such as in a steep downhill scenario, it switches to dual-motor energy recovery mode, and the second motor 15 and the first motor 13 simultaneously recover kinetic energy to charge the battery. When the SOS of the vehicle's power battery 16 is low or the engine 11 (also called a heat engine) is started at low temperature, the engine 11 starts and enters the parking power generation mode, so that the engine 11 drives the first motor 13 to generate electricity, converting the kinetic energy of the engine 11 into electricity for the power battery 16, thereby avoiding power waste of the engine 11.

[0058] The working modes of the electric drive system are as follows:

[0059]

[0060]

[0061] Compared to existing four-wheel drive systems that use extended-range electric drive systems and add motors to drive the rear wheels, the electric drive system of this application reduces the number of motors used, lowers costs, and reduces the difficulty of vehicle integration. Furthermore, the engine 11 can directly drive the vehicle at high speeds. While the engine 11 is driving the vehicle, excess power can drive the first motor 13 to generate electricity, thereby increasing the power utilization of the engine 11, reducing vehicle fuel consumption, and improving fuel economy. A second clutch 3 is arranged on the first intermediate shaft 14. When driven solely by the second motor 15, the second clutch 3 is controlled to disengage, thereby reducing energy loss caused by drag on the engine 11 and the first motor 13 and maximizing system efficiency.

[0062] Compared with the existing plug-in electric drive system combined with the electric drive system to achieve the four-wheel drive structure of the entire vehicle, the electric drive system of the present application only has two clutches, the first clutch 2 and the second clutch 3, which reduces the use of clutches and the transmission gears required for power transmission, making the structure simpler and reducing costs. It can also reduce the overall volume of the electric drive system and the difficulty of arranging the electric drive system on the vehicle body, making the electric drive system applicable to compact vehicles. In addition, arranging the first clutch 2 and the second clutch 3 on different shaft systems makes the system space compact, further reducing the axial dimension, which is conducive to reducing the assembly weight and improving the system power density.

[0063] In one embodiment, the engine 11, input shaft 12, first clutch 2, first motor 13, first intermediate shaft 14, and second clutch 3 can be mounted together in a housing, and the second motor 15 and power battery 16 are separately arranged. For example, the engine 11, input shaft 12, first clutch 2, first motor 13, first intermediate shaft 14, and second clutch 3 are arranged at the front end of the vehicle body, so that the first intermediate shaft 14 is closer to the front wheels of the vehicle, the second motor 15 is arranged at the rear end of the vehicle body, so that the second motor 15 is closer to the rear wheels of the vehicle, and the power battery 16 is arranged in the middle of the vehicle body, so that the wiring between the power battery 16 and the first motor 13 and the second motor 15 is shorter, and the length of the vehicle body is fully utilized to arrange the electric drive system. In other embodiments, the entire electric drive system can be concentrated at the front end of the vehicle body, that is, the engine 11, input shaft 12, first clutch 2, first motor 13, first intermediate shaft 14, second clutch 3, second motor 15, and power battery 16 are all arranged at the front end of the vehicle body.

[0064] In one embodiment, the second engaging member 22 is rotationally connected to the input shaft 12 and is sleeved on the input shaft 12, so that the entire first clutch 2 is located on the input shaft 12, and the second engaging member 22 is more stable when rotating around the input shaft 12. When the second engaging member 22 is separated from the first engaging member 21, the second engaging member 22 can rotate relative to the first engaging member 21, that is, the rotation of the second engaging member 22 does not cause the first engaging member 21 to rotate. When the second engaging member 22 is engaged with the first engaging member 21, the second engaging member 22 and the first engaging member 21 are fixed together. Similarly, the fourth engaging member 31 is rotationally connected to the first intermediate shaft 14, and the entire second clutch 3 is mounted on the first intermediate shaft 14, and the fourth engaging member 31 is more stable when rotating around the first intermediate shaft 14. When the fourth combining member 31 and the third combining member 32 are in a separated state, the fourth combining member 31 can rotate relative to the third combining member 32, that is, when the fourth combining member 31 rotates, it will not drive the third combining member 32 to rotate; when the fourth combining member 31 and the third combining member 32 are in a combined state, the fourth combining member 31 and the third combining member 32 are fixed together.

[0065] The second coupling member 22 is provided with an input driving gear 23 , and the fourth coupling member 31 is provided with a sixth gear 33 . The sixth gear 33 is transmission-connected to the input driving gear 23 , thereby realizing transmission connection between the fourth coupling member 31 and the second coupling member 22 .

[0066] In one embodiment, if Figure 1 As shown, the first coupling member 21 is a first clutch outer hub, and the second coupling member 22 is a first clutch inner hub. The first clutch inner hub is disposed inside the first clutch outer hub, and the input driving gear 23 is located axially outward of the first clutch outer hub. Because the first clutch inner hub is disposed inside the first clutch outer hub, the diameter of the first clutch outer hub is larger than that of the first clutch inner hub. In this embodiment, the first clutch outer hub is connected to the input shaft 12, so that when the engine 11 is not operating and the vehicle is driven by the first motor 13 and the second motor 15, or when the vehicle is coasting, the first clutch 2 is disengaged. That is, the first clutch outer hub (first coupling member 21) does not rotate, while the first clutch inner hub (second coupling member 22) rotates, reducing the centrifugal force on the second coupling member 22. This makes the first clutch 2 more stable during vehicle motion, improves its service life, and reduces noise.

[0067] In other embodiments, the first coupling member 21 is the first clutch inner hub, and the second coupling member 22 is the first clutch outer hub, which can also achieve the coupling or separation function between the first coupling member 21 and the second coupling member 22.

[0068] Similarly, the third coupling member 32 is the second clutch inner hub, the fourth coupling member 31 is the second clutch outer hub, the second clutch inner hub is arranged inside the second clutch outer hub, and the sixth gear 33 is located axially outside the second clutch outer hub.

[0069] Since the second clutch inner hub is arranged inside the second clutch outer hub, the diameter of the second clutch outer hub is larger than the diameter of the second clutch inner hub. The second clutch inner hub of this embodiment is connected to the first intermediate shaft 14, so that when the engine 11 is not working and the vehicle is driven by the second motor 15 or the vehicle is in a coasting state, the second clutch 3 is in a disengaged state, that is, the second clutch outer hub (fourth coupling member 31) does not rotate, and the second clutch inner hub (third coupling member 32) rotates, so that the centrifugal force of the third coupling member 32 is smaller, so the second clutch 3 is more stable during the movement of the vehicle, the service life is improved, and the noise is reduced.

[0070] In other embodiments, the fourth coupling member 31 is the second clutch inner hub, and the third coupling member 32 is the second clutch outer hub, which can also achieve the coupling or separation function between the fourth coupling member 31 and the third coupling member 32 .

[0071] A first gear 131 is provided on the output shaft of the first motor 13. The first gear 131 meshes with the input driving gear 23 to realize a transmission connection between the first motor 13 and the second coupling member 22. The diameter of the first gear 131 is smaller than the input driving gear 23, so that when the power of the engine 11 passes through the input driving gear 23 and the first gear 131 to drive the first motor 13 to generate electricity, speed increase and torque reduction are achieved, that is, the torque demand of the first motor 13 is reduced, so that the volume of the first motor 13 can be made smaller. Conversely, when the first motor 13 drags the engine 11 to rotate to achieve the function of assisting the engine 11 to start quickly, the power of the first motor 13 passes through the first gear 131 and the input driving gear 23 to achieve the effect of increasing torque, which also reduces the torque demand of the first motor 13, so that the volume of the first motor 13 can be made smaller.

[0072] Example 1:

[0073] See Figure 1 There is only one input driving gear 23, and the first gear 131 and the sixth gear 33 are both engaged with the input driving gear 23, reducing one input shaft 12 gear, thereby achieving a more compact layout, and the first gear 131, the driving gear 23 and the sixth gear 33 are coplanar, making the axial dimension of the assembly shorter and reducing the gear meshing loss.

[0074] Example 2:

[0075] Referring to FIG11 , the input driving gear 23 includes a first input driving gear 231 and a second input driving gear 232. The first input driving gear 231 and the second input driving gear 232 are arranged axially along the input shaft 12. The first input driving gear 231 meshes with the first gear 131, and the second input driving gear 232 meshes with the sixth gear 33. In this embodiment, by connecting the first input driving gear 231 and the second input driving gear 232 to the second coupling member 22, the first input driving gear 231 meshes with the first gear 131, and the second input driving gear 232 meshes with the sixth gear 33. This reduces the positional accuracy requirements of the input driving gear 23, the first gear 131, and the sixth gear 33, facilitates the distribution of transmission ratios between the input driving gear 23 and the first gear 131, and between the input driving gear 23 and the sixth gear 33, and reduces the diameter of the gears.

[0076] In one embodiment, the diameter of the second input driving gear 232 is smaller than that of the first input driving gear 231, thereby reducing the diameter of the sixth gear 33. For example, when the engine 11 drives the first motor 13 to generate electricity, it is necessary to increase speed and reduce torque, thereby reducing the size of the first motor 13. Therefore, the diameter of the first gear 131 needs to be smaller than the input driving gear 23. When the power of the engine 11 is used to drive the first wheel end, the diameter of the sixth gear 33 needs to be larger than the diameter of the input driving gear 23, thereby increasing the torque output by the first intermediate shaft 14 and improving the vehicle's power. When the first gear 131 and the sixth gear 33 are connected to the same input driving gear 23, the diameter of the sixth gear 33 needs to be larger than the diameter of the input driving gear 23 to achieve increased torque; when the first gear 131 and the sixth gear 33 are respectively connected to two gears fixed together, that is, the first input driving gear 231 is meshed with the first gear 131, and the second input driving gear 232 is meshed with the sixth gear 33, the diameters of the second input driving gear 232 and the sixth gear 33 can be reduced in equal proportion to ensure that the same transmission ratio is obtained, thereby reducing the diameter of the sixth gear 33.

[0077] Example 3:

[0078] See Figure 12The rotating shaft of the first motor 13 is provided with a center hole, the first motor 13 is sleeved on the input shaft 12, and the first clutch 2 is integrally installed inside the center hole of the rotating shaft of the first motor 13, so that the position of the first motor 13 coincides with the position of the first clutch 2 in the axial direction, thereby reducing the axial length of the electric drive system along the input shaft 12, and the first motor 13 can output a larger torque. Among them, the axial direction of the input shaft 12 is the width direction of the vehicle, thus making it convenient for the electric drive system to be installed on a vehicle with a smaller width. The second coupling 22 is fixed to the rotating shaft of the first motor 13 to realize the connection between the second coupling 22 and the rotating shaft of the first motor 13, thereby eliminating the first gear 131 and the first input driving gear 231, thereby making the structure of the electric drive system simpler and smaller in size, and reducing production costs.

[0079] Specifically, the first coupling member 21 is the first clutch inner hub, and the second coupling member 22 is the first clutch outer hub. The first clutch outer hub is mounted within the center hole of the first motor 13 and is fixedly connected to the first clutch outer hub. The first clutch inner hub is disposed within the first clutch outer hub, facilitating the connection between the first coupling member 21 and the input shaft 12, and between the second coupling member 22 and the first motor 13. The input driving gear 23 is located axially outward from the first motor 13, enabling it to mesh with the sixth gear 33.

[0080] See Figure 1 、 Figure 11 as well as Figure 12 In one embodiment, a fifth gear 141 is provided on the first intermediate shaft 14. The electric drive system further includes a first differential 4, which includes a first differential driven gear 41. The first differential driven gear 41 meshes with the fifth gear 141, and the first wheel end is connected to the output half shaft of the first differential 4. Therefore, the power on the first intermediate shaft 14 can be transmitted to the first wheel end 71 through the fifth gear 141 and the first differential 4. The diameter of the first differential driven gear 41 is larger than that of the fifth gear 141, which enables the power to be transmitted from the first intermediate shaft 14 to the first differential 4 to reduce speed and increase torque. In other words, a speed reduction structure is formed between the fifth gear 141 and the first differential driven gear 41.

[0081] exist Figure 1 and Figure 11 In the illustrated embodiment, the first differential driven gear 41 and the fifth gear 141 are coplanar, and the fifth gear 141 at least partially overlaps with the first clutch 2 in the axial direction, thereby reducing the axial size of the electric drive system. The first differential 4 at least partially overlaps with the first clutch 2 in the axial direction, thereby reducing the axial size of the electric drive system. In some embodiments, the second clutch 3 at least partially overlaps with the first differential 4 in the axial direction, thereby reducing the axial size of the electric drive system.

[0082] exist Figure 11 In the embodiment shown, the first clutch 2 and the first differential 4 are axially overlapped, and the fifth gear 141 and the second clutch 3 are axially overlapped with the first clutch 2 and the first differential 4, thereby reducing the axial size of the electric drive system.

[0083] exist Figure 11 In the illustrated embodiment, the second input driving gear 232 is located on the side of the first input driving gear 231 away from the first clutch 2, and the second clutch 3 is located between the fifth gear 141 and the sixth gear 33, and overlaps with the first input driving gear 231, making the structure of the electric drive system more compact.

[0084] exist Figure 12 In the illustrated embodiment, the first differential driven gear 41 and the fifth gear 141 are coplanar, and the second clutch 3 and the first differential 4 at least partially overlap in the axial direction, thereby reducing the axial size of the electric drive system.

[0085] See Figure 1 、 Figure 11 and Figure 12 A second gear 151 is provided on the output shaft of the second motor 15. The electric drive system also includes a transmission assembly 5 and a second differential 6. The transmission assembly 5 includes a second intermediate shaft 51, a third gear 52 and a fourth gear 53. The third gear 52 and the fourth gear 53 are arranged at intervals on the second intermediate shaft 51. The third gear 52 is engaged with the second gear 151. The second differential 6 includes a second differential driven gear 61. The second differential driven gear 61 is engaged with the fourth gear 53, so that the power of the second motor 15 can be transmitted to the second wheel end through the second gear 151, the third gear 52, the second intermediate shaft 51, the fourth gear 53 and the second differential 6. Among them, the diameter of the third gear 52 is larger than the diameter of the second gear 151, and the diameter of the second differential driven gear 61 is larger than the diameter of the fourth gear 53, so that the power of the second motor 15 is reduced in speed and increased in torque when passing between the second gear 151 and the third gear 52 and between the fourth gear 53 and the second differential driven gear 61, that is, two-stage deceleration is achieved, thereby increasing the torque output to the second wheel end.

[0086] In one embodiment, the second differential 6 and the first differential 4 overlap in the axial direction, and the transmission assembly 5 and the second differential 6 at least partially overlap in the axial direction, so that the size of the electric drive system in the axial direction is smaller.

[0087] Specifically, the second differential driven gear 61, the fourth gear 53, and the fifth gear 141 are arranged in the same plane, the third gear 52 is coplanar with the second gear 151, and at least partially overlaps with the second clutch 3 in the axial direction, thereby reducing the axial size of the electric drive system.

[0088] In a preferred embodiment, the first clutch 2 is a wet clutch, so that when the first motor 13 assists the engine 11 in starting, the first clutch 2 realizes a sliding engagement when engaged, that is, during the engagement process of the first clutch 2, there is first sliding friction between the first coupling member 21 and the second coupling member 22 (the first coupling member 21 and the second coupling member 22 rotate relative to each other, rather than directly reaching a synchronous state), and then the first coupling member 21 and the second coupling member 22 are synchronized. Otherwise, it will cause a start shock or a sense of frustration, thereby improving the comfort of the vehicle. For example, when the pure electric drive mode enters the series mode, the vehicle speed is high, that is, the speed of the first motor 13 is high, and the engine 11 cannot be started by hard connection or switching the clutch, otherwise it will cause a start shock or a sense of frustration. The first clutch 2 is a wet clutch, so that when the engine 11 is started at a higher vehicle speed, the engine 11 can be started quickly and smoothly.

[0089] In a preferred embodiment, the second clutch 3 is used to transmit the power of the engine 11 to the first wheel or disconnect the first motor 13 when operating in pure electric mode to reduce drag losses, improve the system efficiency of the pure electric two-wheel drive, and thus extend the range. The second clutch 3 is a wet clutch, which ensures rapid response and smooth switching of the power of the engine 11, avoiding starting shock or jerk, and improving vehicle comfort.

[0090] In the above description, the first clutch 2 and the second clutch 3 are mode switching actuators, and the structure is not limited to wet clutches, dry clutches, synchronizers and other types of actuators.

[0091] In one embodiment, a torsional vibration damper 17 is provided on the output shaft of the engine 11, and the engine 11 is connected to the input shaft 12 through the torsional vibration damper 17 to prevent the vibration of the engine 11 from being transmitted to the input shaft 12, reduce the vibration of the input shaft 12, thereby improving the stability of the electric drive system and increasing the service life.

[0092] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the scope of protection of the present invention.

Claims

1. An electric drive system, characterized in that: include: engine; an input shaft connected to the engine; The first clutch comprises a first coupling member and a second coupling member, wherein the first coupling member is fixedly connected to the input shaft, and the second coupling member can be coupled to or separated from the first coupling member; a first motor, drivingly connected to the second coupling member; a first intermediate shaft, parallel to the input shaft and configured for transmission connection with the first wheel end; a second clutch comprising a third coupling member and a fourth coupling member, wherein the third coupling member is fixedly connected to the first intermediate shaft, the fourth coupling member is drivingly connected to the second coupling member, and the fourth coupling member is engaged or disengaged with the third coupling member; A second motor is used for transmission connection with the second wheel end; A power battery is electrically connected to the first motor and the second motor.

2. The electric drive system according to claim 1, characterized in that: The second coupling member is rotatably connected to the input shaft, and when the second coupling member and the first coupling member are in a separated state, the second coupling member can rotate relative to the first coupling member, and the second coupling member is provided with an input driving gear; The fourth coupling member is rotationally connected to the first intermediate shaft, and when the fourth coupling member and the third coupling member are in a separated state, the fourth coupling member can rotate relative to the third coupling member. The fourth coupling member is provided with a sixth gear, and the sixth gear is transmission-connected to the input driving gear.

3. The electric drive system according to claim 2, characterized in that: The first coupling member is a first clutch outer hub, the second coupling member is a first clutch inner hub, the first clutch inner hub is arranged inside the first clutch outer hub, and the input driving gear is located axially outside the first clutch outer hub; A first gear is provided on the output shaft of the first motor, and the first gear is engaged with the input driving gear. The diameter of the first gear is smaller than that of the input driving gear.

4. The electric drive system according to claim 3, characterized in that: The input driving gear includes a first input driving gear and a second input driving gear, the first input driving gear and the second input driving gear are distributed along the axial direction of the input shaft, the first input driving gear is meshed with the first gear, and the second input driving gear is meshed with the sixth gear; The diameter of the second input driving gear is smaller than the diameter of the first input driving gear.

5. The electric drive system according to claim 2, characterized in that: The rotating shaft of the first motor is provided with a central hole, and the first clutch is located inside the central hole; The first coupling member is a first clutch inner hub, the second coupling member is a first clutch outer hub, the first clutch inner hub is arranged inside the first clutch outer hub, the first clutch outer hub is fixedly connected to the rotating shaft of the first motor, and the input driving gear is located axially outside the first motor.

6. The electric drive system according to claim 2, characterized in that: The third coupling member is the second clutch inner hub, the fourth coupling member is the second clutch outer hub, the second clutch inner hub is arranged inside the second clutch outer hub, and the sixth gear is located axially outside the second clutch outer hub.

7. The electric drive system according to any one of claims 1 to 6, characterized in that: A fifth gear is provided on the first intermediate shaft; The electric drive system further includes: The first differential includes a first differential driven gear, the first differential driven gear is meshed with the fifth gear, and the diameter of the first differential driven gear is greater than the diameter of the fifth gear.

8. The electric drive system according to any one of claims 1 to 6, characterized in that: The output shaft of the second motor is provided with a second gear; The electric drive system further includes: a transmission assembly comprising a second intermediate shaft, a third gear, and a fourth gear, wherein the third gear and the fourth gear are spaced apart on the second intermediate shaft, the third gear meshes with the second gear, and the diameter of the third gear is greater than that of the second gear; The second differential includes a second differential driven gear, the second differential driven gear is meshed with the fourth gear, and the diameter of the second differential driven gear is larger than the diameter of the fourth gear.

9. The electric drive system according to any one of claims 1 to 6, characterized in that: The operating modes of the electric drive system include parallel four-wheel drive mode, pure electric four-wheel drive mode, engine direct drive mode, parallel two-wheel drive mode, pure electric two-wheel drive mode, series mode, parking power generation mode, single motor energy recovery mode, and dual motor energy recovery mode, among which: When the parallel four-wheel drive mode is in operation, the first clutch and the second clutch are both engaged, the engine and the second motor are in operation, the power of the engine is transmitted to the first wheel end through the first clutch, the second clutch and the first intermediate shaft, and the second motor drives the second wheel end; When the vehicle is in the pure electric four-wheel drive mode, the first clutch is disengaged, the second clutch is engaged, the first motor and the second motor are in operation, the engine is inoperative, and the power of the first motor is transmitted to the first wheel end through the second engaging member of the first clutch, the second clutch, and the first intermediate shaft, and the second motor drives the second wheel end; When the engine is in direct drive mode, the first clutch and the second clutch are both engaged, the engine is operating, the first motor and the second motor are not operating, and the power of the engine is transmitted to the first wheel end through the first clutch, the second clutch, and the first intermediate shaft; When operating in the parallel two-wheel drive mode, the first clutch and the second clutch are both engaged, the engine is operating, the second motor is not operating, a portion of the engine power is transmitted to the first wheel end through the first clutch, the second clutch, and the first intermediate shaft, and the remaining power drives the first motor to generate electricity through the first clutch; When the pure electric two-wheel drive mode is in operation, the first clutch and the second clutch are both disengaged, the engine and the first motor are both inoperative, and the second motor drives the second wheel end; When operating in the series mode, the first clutch is engaged, the second clutch is disengaged, the engine drives the first motor to generate electricity, and the second motor drives the second wheel end; When the vehicle is in the parking power generation mode, the first clutch is engaged, the second clutch is disengaged, the second motor is not working, and the engine drives the first motor to generate electricity; When the single-motor energy recovery mode is in operation, the first clutch and the second clutch are both disengaged, and the first wheel end and the second wheel end drive the second motor to generate electricity; When the dual-motor energy recovery mode is in operation, the first clutch is disengaged and the second clutch is engaged, and the first wheel end and the second wheel end drive the first motor and the second motor to generate electricity.

10. A four-wheel drive vehicle, characterized in that: include: body; The electric drive system according to any one of claims 1 to 9, mounted on the vehicle body; a first wheel end, drivingly connected to a first intermediate shaft of the electric drive system; The second wheel end is transmission-connected to the second motor.

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