CN204547733U - Two gear variable speed drive systems of the plug-in hybrid-power automobile of single drive motor - Google Patents

Abstract

The utility model relates to a two-speed variable-speed drive system of a plug-in hybrid electric vehicle with a single drive motor. The system includes an engine, a driving motor, a dual-clutch two-speed transmission, a final reduction mechanism and a speed reducer, and also includes a brake and a power coupling mechanism; the power coupling mechanism is composed of the driving motor, a clutch and a planetary gear mechanism. The utility model integrates a driving motor, a power coupling mechanism of a planetary gear mechanism, a dual-clutch two-speed transmission and a differential, and compared with a hybrid drive system in which power components are separated, the utility model has a high degree of integration and a short transmission route; The utility model can realize the starting engine mode, parking charging mode, pure electric driving mode, engine independent driving mode, engine driving charging mode, hybrid driving mode, regenerative braking mode and pure electric reversing mode of the vehicle, which is different from the traditional dual-motor planetary Compared with the hybrid drive system of the gear mechanism, the power transmission efficiency is high, the structure is simple, and the cost is low.

Description

Two-speed variable-speed drive system for plug-in hybrid electric vehicles with a single drive motor

technical field

The utility model belongs to the technical field of hybrid electric vehicles, in particular to a two-speed variable speed drive system of a plug-in hybrid electric vehicle.

Background technique

At present, energy issues and environmental pollution have become two prominent problems faced by traditional fuel vehicles. Hybrid vehicles that combine the advantages of pure electric vehicles and traditional fuel vehicles have become a research hotspot in the world's automotive industry. Plug-in hybrid electric vehicle is a new type of hybrid electric vehicle that can be charged externally. Its biggest feature is the combination of hybrid drive system and pure electric drive system. The internal combustion engine is the main hybrid mode, and the external public grid (mainly the evening low power) can be used to balance the vehicle power battery, which can improve the efficiency of the generator set of the power plant, and relieve the power supply pressure. The plug-in hybrid electric vehicle drive system includes multiple power sources, and its key technology is that the hybrid drive system can operate in multiple drive modes to meet the power requirements of the vehicle under variable operating conditions.

Most of the existing hybrid drive systems use planetary gear train schemes, such as the "Prius" launched by Toyota, the "Escape" launched by Ford of the United States, and the "Allison" launched by General Motors of the United States. power system. However, these hybrid power systems introduced by the above automobile companies all adopt the form of double motors, and some even adopt the form of double planetary gear mechanism, which leads to high cost and complicated structure of the system.

At present, electric vehicles or fuel vehicles use multi-speed automatic transmissions, which make the structure of the transmission system complex, increase the weight of the vehicle, and reduce energy utilization efficiency, or use a single fixed speed ratio reducer, so that the engine and drive motor often work in the low-efficiency area , it is difficult to take into account the requirements of vehicle power and economy, and the use of two-speed transmission system can keep the engine and drive motor in a high-efficiency working area, so as to give full play to the advantages of high energy utilization of hybrid vehicles.

Dual-clutch transmission combines the advantages of manual transmission and traditional hydromechanical automatic transmission, so that the vehicle has the same driving convenience and comfort as the hydromechanical transmission vehicle, and has better performance than the hydromechanical transmission. Fuel economy, high transmission efficiency and low manufacturing cost compared with other types of automatic transmissions.

In view of the lack of a unified design and arrangement of the main components of the hybrid vehicle drive system (engine, drive motor, power coupling device, transmission mechanism and differential) during the research and development process, the hybrid drive system has a complex structure, bulky size, increased weight, and system dispersion. , The cost is high, which is not conducive to its development and industrialization. The integration of drive motor, power coupling device, speed change mechanism and differential is an inevitable choice for the development of hybrid electric vehicles.

Utility model content

In order to solve the defects or deficiencies in the above-mentioned prior art, the utility model provides a plug-in hybrid electric vehicle with a single driving motor integrating a driving motor and a power coupling mechanism, a dual-clutch two-speed transmission and a differential. Two-speed variable speed drive system.

The specific technical solutions are as follows:

The two-speed variable-speed drive system of a plug-in hybrid electric vehicle with a single drive motor includes an engine 1, a drive motor, a dual-clutch two-speed transmission, a final reduction mechanism and a differential, and the dual-clutch two-speed transmission includes a dual clutch 30, two transmission;

It also includes a brake 3 and a power coupling mechanism; the power coupling mechanism is composed of the drive motor, a clutch 6 and a planetary gear mechanism, and the clutch 6 is a multi-plate wet friction clutch;

The rotor 31 of the drive motor is an annular rotor; the clutch 6 is located on one axial side of the rotor 31; 7, and is located in the annular rotor; the power coupling input shaft 5 of the power coupling mechanism is located on one side of the clutch 6, and the power coupling output shaft 11 is located on the other side; the brake 3 is arranged on the input end of the power coupling input shaft 5 , the input end of the power coupling input shaft 5 is connected to the power output shaft 2 of the engine when working;

In the engine driving mode, the brake 3 is in a non-braking state, the rotor 31 of the driving motor is in a free state, the clutch 6 is engaged, and the ring gear 8, the sun gear 10 and the planetary gear carrier 7 of the planetary gear mechanism are Mechanically locked, the engine 1 drives the ring gear 8, the sun gear 10 and the planetary carrier 7 of the planetary gear mechanism to rotate, and the power is transmitted to the dual-clutch two-speed transmission through the power coupling output shaft 11 to drive the vehicle to run;

In the motor drive mode, the brake 3 is in a locked state, the ring gear 8 of the planetary gear mechanism and the engine 1 are in a locked state, and the clutch 6 is disengaged; the sun gear 10 and the planetary gear carrier 7 of the planetary gear mechanism are respectively Rotating at respective speeds, the rotor 31 drives the sun gear 10 and the planetary gear carrier 7 to rotate, and the power is transmitted to the dual-clutch two-speed transmission through the power coupling output shaft 11 to drive the vehicle to run;

In the hybrid driving mode, when the vehicle is under high-load acceleration and climbing conditions, both the engine 1 and the drive motor participate in work; the brake 3 is in a non-braking state, and the clutch 6 is disengaged; the planetary gear mechanism The ring gear 8, the sun gear 10 and the planetary gear carrier 7 rotate at respective speeds; the power output shaft 2 of the engine is connected with the ring gear 8 of the planetary gear mechanism through the power coupling input shaft 5, and the rotor 31 of the drive motor It is connected with the sun gear 10 of the planetary gear mechanism, the planetary gear frame 7 is connected with the power coupling output shaft 11, the engine 1 drives the ring gear 8 to rotate, the rotor 31 of the drive motor drives the sun gear 10 to rotate, and the planetary gear frame 7 is output through power coupling The shaft 11 transmits power to the dual-clutch two-speed transmission to drive the vehicle to run.

In the regenerative braking mode, when the vehicle decelerates and brakes, the dual-clutch two-speed transmission is in the low gear working state, the brake 3 is locked, the ring gear 8 of the planetary gear mechanism and the engine 1 are in the locked state, and the clutch 6 Separation; the sun gear 10 of the planetary gear mechanism and the planetary wheel carrier 7 rotate at respective speeds respectively, and the braking force of the wheel 19 passes through the differential gear, the dual-clutch two-speed transmission, and the planetary wheel carrier 7 of the planetary gear mechanism And the sun gear 10 drives the rotor 31 of the driving motor to reverse, the driving motor enters the power generation mode, recovers the braking energy, and charges the power battery pack 34 through the driving motor controller 33 .

The beneficial technical effects of the utility model are embodied in the following aspects:

1. A two-gear variable-speed drive system for a plug-in hybrid electric vehicle with a single drive motor of the present utility model, which respectively integrates the drive motor and the power coupling mechanism of the planetary gear mechanism, the dual-clutch two-gear transmission and the differential as one, Compared with the driving system of a hybrid electric vehicle with separate power components, it has the advantages of high integration and short transmission line, and is beneficial to the design and layout of the whole vehicle.

2. The two-speed variable speed drive system of a plug-in hybrid electric vehicle with a single drive motor of the present utility model adopts a single drive motor, and realizes the starting engine mode of the vehicle by controlling the clutch and the power coupling mechanism of the planetary gear mechanism , parking charging mode, pure electric driving mode, engine independent driving mode, engine driving charging mode, hybrid driving mode, regenerative braking mode and pure electric reversing mode, and the driving system of a hybrid electric vehicle with a traditional dual-motor planetary gear mechanism Compared with it, it has the advantages of high power transmission efficiency, simple structure and low cost.

3. The two-speed variable speed drive system of a plug-in hybrid electric vehicle with a single drive motor of the present utility model adopts a double-clutch two-speed speed change mechanism, which can improve the power of the whole vehicle compared with a speed change mechanism with a fixed speed ratio. Performance, economy, emission and comfort, improve the efficiency of the engine, drive motor efficiency, prolong the life of the power battery and the mileage of the vehicle.

Description of drawings

Fig. 1 is a driving schematic diagram of the utility model.

Fig. 2 is a schematic structural view of the utility model.

Serial numbers in the above picture: 1. Engine, 2. Power output shaft, 3. Brake, 4. Left half shaft, 5. Power coupling input shaft, 6. Clutch, 7. Planet carrier, 8. Ring gear, 9. Planetary gear , 10. Sun gear, 11. Power coupling output shaft, 12. Differential housing, 13. Left side shaft gear, 14. Planetary gear of differential, 15. Planetary shaft of differential, 16. Right half Shaft gear, 17. Right half shaft, 18. Driven reduction gear, 19. Wheel, 20. First gear driven gear, 21. Intermediate shaft, 22. Second gear driven gear, 23. Driving reduction gear, 24 .first gear driving gear, 25. output shaft of first clutch, 26. second gear driving gear, 27. output shaft of second clutch, 28. second clutch, 29. first clutch, 30. double clutch, 31. Rotor, 32. Stator, 33. Drive motor controller, 34. Power battery pack, 35. Car charger, 36. Charging plug.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described further by embodiment.

Example

Referring to Fig. 1 and Fig. 2, the two-speed variable-speed drive system of a plug-in hybrid electric vehicle with a single drive motor includes an engine 1, a drive motor, a dual-clutch two-speed transmission, a final reduction mechanism and a speed reducer. The dual-clutch two-speed transmission includes a dual-clutch 30 and a two-speed transmission; it also includes a brake 3 and a power coupling mechanism; the power coupling mechanism is composed of the drive motor, clutch 6 and planetary gear mechanism.

The drive motor is a permanent magnet brushless motor, including a stator 32 and a rotor 31; the rotor 31 is an annular rotor; the clutch 6 is located on one axial side of the rotor 31; the planetary gear mechanism consists of a ring gear 8, a sun gear 10, two or more The planetary gear 9 and the planetary gear frame 7 are formed, and are located in the annular rotor;

The power coupling input shaft 5 of the power coupling mechanism is located on one side of the clutch 6, and the power coupling output shaft 11 is located on the other side; the brake 3 is arranged on the input end of the power coupling input shaft 5, and the input end of the power coupling input shaft 5 works is connected to the power take-off shaft 2 of the engine.

The clutch 6 is a multi-plate wet friction clutch, the driving plate of the clutch 6 is fixedly connected to the power coupling input shaft 5, the driven plate of the clutch 6 is fixedly connected to one axial side of the rotor 31; the output end of the power coupling input shaft 5 is connected to The ring gear 8 of the planetary gear mechanism;

The other axial side of the sun gear 10 and the rotor 31 of the planetary gear mechanism is fixedly connected by a connecting plate; the wheel shaft of the sun gear 10 is a hollow shaft and is a rotor shaft; the rotor 31 is fixedly connected by a connecting piece on the other axial side Rotor shaft; the wheel shaft of the sun gear 10 is inserted with a power coupling output shaft 11; one end of the power coupling output shaft 11 is the output end, and is connected to the housing of the dual clutch 30, and the other end of the power coupling output shaft 11 is connected to the planet Wheel frame7.

Referring to FIG. 1 and FIG. 2 , the power output shaft 2 of the engine 1 is connected with the power coupling input shaft 5 . The first clutch 29 of the dual-clutch two-speed transmission is connected with the first gear driving gear 24 of the two-speed transmission through the output shaft 25 of the first clutch, and is constantly meshed with the first gear driven gear 20. The second clutch 28 is connected with the second gear driving gear 26 through the output shaft 27 of the second clutch, and is sleeved on the output shaft 25 of the first clutch, and is constantly meshed with the second gear driven gear 22. The gear 20 and the second gear driven gear 22 are respectively sleeved on the intermediate shaft 21 of the two-speed transmission mechanism; The driven reduction gear 18 of the main reduction mechanism is constantly meshed, and the driven reduction gear 18 of the main reduction mechanism is fixedly sleeved with the differential case 12 as a whole, and passes through the planetary gear 14 of the differential, the left side gear 13, and the right side gear 16 and left half shaft 4, right half shaft 17 drive wheel 19; Brake 3 is located on the input end of power coupling input shaft 5, and the input end of power coupling input shaft 5 is connected with the power output shaft 2 of engine when working, by controlling The braking or release of the brake 3 realizes the locking and releasing of the power output shaft 2 of the engine, ensuring that the engine 1 is turned off and the power output shaft 2 does not rotate in the pure electric driving mode and the regenerative braking mode of the vehicle. By controlling the combination and separation of the active plate and the driven plate of the clutch 6, the combination and separation of the sun gear 10 and the ring gear 8 of the planetary gear mechanism are realized, and at the same time, the engine 1, the drive motor rotor 31 and the brake 3 are coordinated and controlled to realize the vehicle's rotation respectively. Starting engine mode, parking charging mode, pure electric driving mode, engine independent driving mode, engine running charging mode, hybrid driving mode, regenerative braking mode and pure electric reverse mode, and by controlling the dual-clutch two-speed transmission respectively Combining and disengaging the first clutch 29 and the second clutch 28 realizes smooth switching between low gear and high gear, and improves the gear shifting power and driving comfort of the vehicle.

The working principle of the utility model is described as follows:

(1) Engine driving mode

The brake 3 is in a non-braking state, the rotor 31 of the driving motor is in a free state, the clutch 6 is combined, the ring gear 8, the sun gear 10 and the planetary gear carrier 7 of the planetary gear mechanism are mechanically locked; the engine 1 drives the The ring gear 8, the sun gear 10 and the planetary gear carrier 7 rotate, and the power is transmitted to the dual-clutch two-speed transmission through the power coupling output shaft 11 to drive the vehicle to run. The engine driving mode includes an engine driving mode alone, an engine driving charging mode and a parking charging mode.

(1.1) Engine alone driving mode

When the vehicle is running at a constant speed and the engine is working in a high-efficiency zone, the vehicle enters the engine-only driving mode. At this time, the brake 3 is in a non-braking state, the rotor 31 of the drive motor is in a free state, and the clutch 6 is engaged. The coupling mechanism is transmitted to the dual-clutch two-speed transmission, and the dual clutch 30 is controlled to drive the vehicle to run in low gear and high gear respectively.

When the vehicle was running in low gear, the second clutch 28 of the dual clutch was separated, and the first clutch 29 of the dual clutch was combined. The power drove the first gear driving gear 24 to rotate through the output shaft 25 of the first clutch, and the first gear driving gear 24 drives the first gear driven gear 20 to rotate, and the driving reduction gear 23 drives the driven reduction gear 18 to rotate, and realizes the engine-only driving operation mode of the low gear of the vehicle through the differential.

When the vehicle was running in the high-speed gear working state, the first clutch 29 of the dual clutch was separated, and the second clutch 28 of the dual clutch was combined. The power drove the second gear driving gear 26 to rotate through the output shaft 27 of the second clutch, and the second gear driving gear 26 drives the second gear driven gear 21 to rotate, and the driving reduction gear 23 drives the driven reduction gear 18 to rotate, and realizes the engine independent driving operation mode of the high gear of the vehicle through the differential.

(1.2) Engine driving charging mode

When the power battery pack 34 is insufficient or the vehicle is running under low load conditions, the vehicle enters the engine driving charging mode under the premise of ensuring the normal driving performance of the vehicle, so as to increase the engine load rate and make it work in a high-efficiency zone. At this time, the brake 3 is in the non-braking state, the clutch 6 is combined, the driving motor is in the power generation state, and the output power of the engine 1 is transmitted to the dual-clutch two-speed transmission through the power coupling mechanism to drive the vehicle to run; at the same time, the sun gear of the planetary gear mechanism 10 drives the rotor 31 of the drive motor to rotate, and charges the power battery pack 34 through the drive motor controller 33 to maintain the battery power level.

(1.3) Parking charging mode

When the power battery pack 34 is insufficient and the engine 1 needs to be charged, the vehicle enters the parking power generation mode. At this time, the brake 3 is in a non-braking state, the clutch 6 is combined, and the driving motor is in a power generation state. The first clutch of the dual clutch 29 and the second clutch 28 are in the disengaged state, the engine 1 drives the ring gear 8 and the sun gear 10 of the planetary gear mechanism to rotate, and drives the drive motor rotor 31 to rotate, and the power battery pack 34 is charged by the drive motor controller 33 .

(2) Motor drive mode

The brake 3 is in the locked state, the ring gear 8 of the planetary gear mechanism and the engine 1 are in the locked state, and the clutch 6 is separated; the sun gear 10 and the planetary gear carrier 7 of the planetary gear mechanism rotate at their respective speeds, and the rotor 31 drives the sun gear 10 and the planetary wheel carrier 7 rotate, and the power is transmitted to the dual-clutch two-speed transmission through the power coupling output shaft 11 to drive the vehicle to run. The motor drive mode includes a pure electric drive mode, a starting engine mode, a pure electric reverse mode and a grid charging mode.

(2.1) Pure electric drive mode

When the vehicle is running at low speed or the engine working efficiency is low, the vehicle enters the pure electric driving mode. At this time, the brake 3 is locked, the engine 1 is locked, the ring gear 8 of the planetary gear mechanism is locked together with the engine, the clutch 6 is separated, the drive motor is in the drive state, and the drive motor rotor 31 drives the sun gear 10, The planetary wheel carrier 7 rotates, and the power is transmitted to the dual-clutch two-speed transmission through the output shaft 11 of the power coupling mechanism, and the vehicle is driven to run in low gear and high gear by controlling the dual clutch 30 .

When the vehicle is running in a low gear working state, the second clutch 28 of the dual clutch is disengaged, and the first clutch 29 of the dual clutch is combined to realize the pure electric driving operation mode of the low gear of the vehicle.

When the vehicle is running in a high-speed working state, the first clutch 29 of the dual-clutch is separated, and the second clutch 28 of the dual-clutch is combined to realize the pure electric drive operation mode of the high-speed vehicle.

(2.2) Start engine mode

When starting the engine, the brake 3 is in a non-braking state, the engine 1 is in a non-locking state, the clutch 6 is engaged, the ring gear 8, the sun gear 10 and the planetary gear carrier 7 of the planetary gear mechanism are mechanically locked, and the double clutch The first clutch 29 and the second clutch 28 are all in the disengaged state, the driving motor is in the driving state, the driving motor rotor 31 drives the sun gear 10 and the ring gear 8 of the planetary gear mechanism to rotate, and drives the engine through the input shaft 5 of the power coupling mechanism The PTO shaft 2 rotates to start the engine 1.

(2.3) Pure electric reversing mode

When the vehicle is reversing, the brake 3 is in the locked state, the engine 1 is in the locked state, the clutch 6 is disengaged, the ring gear 8 of the planetary gear mechanism is in the locked state together with the engine 1, the drive motor rotor 31 is reversed, and through the sun gear of the planetary gear mechanism 10 and the planetary carrier 7 transmit power to the dual-clutch two-speed transmission, the second clutch 28 of the dual-clutch is disengaged, and the first clutch 29 of the dual-clutch is combined to realize the reverse running of the vehicle in low gear.

(2.4) Grid charging mode

At night or when necessary, the vehicle is parked at the charging pile, the brake 3 is in the locked state, the engine 1 is in the off state, the clutch 6 is disengaged, the drive motor is in the power-off and locked state, and the vehicle charger 35 is connected to the power grid of the charging pile through the charging plug 36. Connect, and safely charge the power battery pack 34 according to the charging strategy set.

(3) Hybrid drive mode

When the vehicle is running under high-load (acceleration, climbing) conditions, the engine 1 and the drive motor all participate in work; the brake 3 is in a non-braking state, and the clutch 6 is disengaged; the ring gear 8 of the planetary gear mechanism , the sun gear 10 and the planetary gear carrier 7 rotate at respective speeds; the power output shaft 2 of the engine is connected with the ring gear 8 of the planetary gear mechanism through the power coupling input shaft 5, and the rotor 31 of the drive motor is connected with the planetary gear The sun gear 10 of the mechanism is connected, the planetary gear carrier 7 is connected with the power coupling output shaft 11, the engine 1 drives the ring gear 8 to rotate, the rotor 31 of the driving motor drives the sun gear 10 to rotate, and the planetary gear carrier 7 is connected to the power coupling output shaft 11. The power is transmitted to the dual-clutch two-speed transmission to drive the vehicle to run.

(4) regenerative braking mode,

When the vehicle decelerates and brakes, the dual-clutch two-speed transmission is in a low gear working state, the brake 3 is locked, the ring gear 8 of the planetary gear mechanism and the engine 1 are in a locked state, and the clutch 6 is disengaged; the planetary gear The sun gear 10 and the planetary gear carrier 7 of the mechanism rotate at respective speeds, and the braking force of the wheels 19 drives the drive motor through the differential, the dual-clutch two-speed transmission, the planetary gear carrier 7 and the sun gear 10 of the planetary gear mechanism. The rotor 31 is reversed, the drive motor enters the power generation mode, the braking energy is recovered, and the power battery pack 34 is charged through the drive motor controller 33 .

Claims (3)

1. The two-gear variable-speed drive system of the plug-in hybrid electric vehicle with a single drive motor, comprising an engine (1), a drive motor, a dual-clutch two-gear transmission, a main reduction mechanism and a differential, and the dual-clutch two-gear transmission includes Dual-clutch (30), two-speed transmission; characterized in that: It also includes a brake (3) and a power coupling mechanism; the power coupling mechanism is composed of the driving motor, a clutch (6) and a planetary gear mechanism, and the clutch (6) is a multi-plate wet friction clutch; The rotor (31) of the drive motor is an annular rotor; the clutch (6) is located on one axial side of the rotor (31); The planetary gear mechanism is composed of a ring gear (8), a sun gear (10), more than two planetary gears (9) and a planetary gear carrier (7), and is located in the annular rotor; The power coupling input shaft (5) of the power coupling mechanism is located on one side of the clutch (6), and the power coupling output shaft (11) is located on the other side; the brake (3) is arranged on the input end of the power coupling input shaft (5) , the input end of the power coupling input shaft (5) is connected to the power output shaft (2) of the engine when working; In the engine driving mode, the brake (3) is in a non-braking state, the rotor (31) of the driving motor is in a free state, the clutch (6) is combined, and the ring gear (8) of the planetary gear mechanism, Sun gear (10) and planet gear carrier (7) is mechanically locked, the engine (1) drives the ring gear (8), the sun gear (10) and the planetary gear carrier (7) of the planetary gear mechanism to rotate, and the power is transmitted through the power coupling output shaft (11) to the dual-clutch two-speed transmission to drive the vehicle to run; In the motor drive mode, the brake (3) is in a locked state, the ring gear (8) of the planetary gear mechanism and the engine (1) are in a locked state, and the clutch (6) is separated; the sun of the planetary gear mechanism The wheel (10) and the planetary gear carrier (7) rotate at their respective speeds, the rotor (31) drives the sun gear (10) and the planetary gear carrier (7) to rotate, and the power is output through the power coupling shaft (11) transmitted to the dual-clutch two-speed transmission to drive the vehicle to run; In hybrid driving mode, when the vehicle is running under high load conditions, both the engine (1) and the driving motor are involved in work; the brake (3) is in a non-braking state, and the clutch (6) is disengaged; the planetary gear The ring gear (8), the sun gear (10) and the planetary gear carrier (7) of the mechanism rotate at respective speeds; the power output shaft (2) of the engine is connected to the planetary gear mechanism through the power coupling input shaft (5) The ring gear (8) is connected, the rotor (31) of the drive motor is connected with the sun gear (10) of the planetary gear mechanism, the planetary gear carrier (7) is connected with the power coupling output shaft (11), and the engine (1) drives the gear The ring (8) rotates, the rotor (31) of the drive motor drives the sun gear (10) to rotate, and the power is transmitted to the dual-clutch two-speed transmission through the planetary gear carrier (7) through the power coupling output shaft (11) to drive the vehicle run; In regenerative braking mode, when the vehicle decelerates and brakes, the dual-clutch two-speed transmission is in the low gear working state, the brake (3) is locked, and the ring gear (8) of the planetary gear mechanism and the engine (1) are locked state, the clutch (6) is disengaged; the sun gear (10) and the planetary carrier (7) of the planetary gear mechanism rotate at their respective speeds, through the differential, dual-clutch two-speed transmission, planetary gear The planetary gear carrier (7) and the sun gear (10) of the mechanism drive the rotor (31) of the driving motor to reverse, the driving motor enters the power generation mode, recovers the braking energy, and feeds the power battery pack (34) through the driving motor controller 33 Charge. 2. The two-gear variable speed drive system of the plug-in hybrid electric vehicle of single drive motor according to claim 1, is characterized in that: The driving plate of the clutch (6) is fixedly connected to the power coupling input shaft (5), and the driven plate of the clutch (6) is fixedly connected to one axial side of the rotor (31); the power coupling input shaft (5) The output end is connected with the ring gear (8) of the planetary gear mechanism; The other axial side of the sun gear (10) of the planetary gear mechanism and the rotor (31) is fixedly connected through a connecting plate; the wheel shaft of the sun gear (10) is a hollow shaft, and is a rotor shaft; The connecting piece to the other side is fixedly connected to the rotor shaft; the power coupling output shaft (11) is inserted in the wheel shaft of the sun gear (10); one end of the power coupling output shaft (11) is an output end, and is connected to The housing of double clutch (30), the other end of power coupling output shaft (11) is connected with planetary wheel carrier (7). 3. The two-speed variable speed drive system of a plug-in hybrid electric vehicle with a single drive motor according to claim 1, wherein the drive motor is a permanent magnet brushless motor or an ISG motor.