Hybrid electric vehicle driving transmission system and transmission method thereof

Abstract

The invention discloses a hybrid electric vehicle driving transmission system and a transmission method thereof, and belongs to the technical field of automobile transmission. An engine is connected with an input shaft, a C2 clutch, a C1 clutch and a driving gear are arranged outside the input shaft, the C2 clutch is connected with a planet carrier, the planet carrier is provided with two planet wheels, the two planet wheels are both in meshed connection with a sun wheel and are in meshed linkage with a gear ring, and the gear ring is fixedly connected with the C2 clutch and the C1 clutch. The sun gear is connected with a rotor shaft of the second motor, a brake B1 is arranged outside the rotor shaft of the second motor, and the brake B1 is connected with the shell; the C1 clutch is connected with the driving gear, a rotor shaft of the first motor is connected with the motor gear, and the driving gear and the motor gear are both in meshed connection with the output unit. A multi-mode power system of pure electricity, series connection and parallel connection double gears, series-parallel power dividing, parking power generation and the like is constructed, and all-working-condition oil consumption optimization is achieved in cooperation with the planet row power dividing characteristic and motor speed regulation compensation.

Description

Technical Field

[0001] The present invention relates to a driving transmission system for a hybrid vehicle and a transmission method thereof, belonging to the technical field of vehicle transmissions. Background Art

[0002] Hybrid vehicle models are usually equipped with two power conversion devices, an engine and an electric motor, which cooperate through a transmission system to drive the wheels. Due to its significant advantages such as low emissions, it has become a new type of vehicle that is being actively developed in the current automotive field. In the field of hybrid transmission systems, according to different power connection methods, it can be divided into three basic forms: series, parallel, and series-parallel.

[0003] The existing hybrid transmissions generally have technical defects such as complex structural design and low system transmission efficiency. Although through the coordinated operation of the electric motor, the engine can operate in a high-efficiency region, thereby improving the efficiency of the entire power system to a certain extent, this technical solution is still difficult to effectively reduce the fuel consumption of the vehicle. In addition, the working mode of the existing hybrid transmission is relatively single, and it is unable to flexibly adjust the power distribution strategy according to the actual driving conditions of the vehicle to improve the working conditions of the whole machine and further enhance the power performance of the hybrid transmission. Summary of the Invention

[0004] To solve the problems existing in the background art, the present invention provides a driving transmission system for a hybrid vehicle and a transmission method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solution: A driving transmission system for a hybrid vehicle includes an engine, motor two, motor one, C2 clutch, C1 clutch, B1 brake, input shaft, sun gear, planet carrier, planet gears, ring gear, drive gear, motor gear, and output unit; the crankshaft of the engine is coaxially and fixedly connected to the input end of the input shaft, the outside of the input shaft is sleeved with a C2 clutch, a C1 clutch, and a drive gear, the input shaft is fixedly connected to the inner hub of the C2 clutch, and the input shaft is rotatably connected to the inner hub of the C1 clutch and the drive gear; the inner hub of the C2 clutch is fixedly connected to one end of the planet carrier, the other end of the planet carrier is provided with two planet gears, both of the two planet gears are meshed with the sun gear and meshed with the ring gear, and the ring gear is fixedly connected to the outer hub of the C2 clutch and the outer hub of the C1 clutch; the sun gear is coaxially and fixedly connected to the rotor shaft of motor two, the outside of the rotor shaft of motor two is coaxially and fixedly sleeved with the inner hub of the B1 brake, and the outer hub of the B1 brake is fixedly connected to the inner wall of the housing; the inner hub of the C1 clutch is fixedly connected to the drive gear, the rotor shaft of motor one is coaxially and fixedly connected to the motor gear, and both the drive gear and the motor gear are meshed with the output unit.

[0006] Further, the output unit includes an output shaft, a driven gear, a main reduction gear, and a differential gear; the driven gear is meshed and connected to both the driving gear and the motor gear, the driven gear is coaxially and fixedly connected to the input end of the output shaft, the output end of the output shaft is coaxially and fixedly connected to the main reduction gear, and the main reduction gear is meshed and connected to the differential gear.

[0007] Further, a torsional damper or a dual-mass flywheel is connected between the crankshaft of the engine and the input shaft.

[0008] A transmission method for the pure electric mode of a hybrid vehicle drive transmission system according to the present invention, the method comprising the following steps: S1: Keep the C2 clutch, the C1 clutch, and the B1 brake in a disengaged state, keep the engine and the second motor in a non-operating state, and keep the first motor in an operating state; S2: Start the first motor to drive the motor gear to rotate; S3: The motor gear drives the driven gear to rotate; S4: The driven gear drives the main reduction gear to rotate through the output shaft; S5: The main reduction gear drives the differential gear to rotate for power output.

[0009] A transmission method for the series mode of a hybrid vehicle drive transmission system according to the present invention, the method comprising the following steps: S1: Keep the C2 clutch in an engaged state, keep the C1 clutch and the B1 brake in a disengaged state, and keep the engine, the second motor, and the first motor in an operating state; S2: The engine drives the C2 clutch to rotate through the input shaft; S3: The C2 clutch drives the planet gear to rotate through the combined action of the ring gear and the planet carrier; S4: The planet gear drives the sun gear to rotate; S5: The sun gear drives the rotor shaft of the second motor to store energy in the energy management system; S6: The first motor receives the energy from the energy management system and drives the motor gear to rotate; S7: The motor gear drives the driven gear to rotate; S8: The driven gear drives the main reduction gear to rotate through the output shaft; S9: The main reduction gear drives the differential gear to rotate for power output.

[0010] A transmission method for the first gear of the parallel mode of a hybrid vehicle drive transmission system according to the present invention, the method comprising the following steps: S1: Engage both the C2 clutch and the C1 clutch, disengage the B1 brake, and operate both the engine, motor two, and motor one. S2: The engine drives the C2 clutch and the C1 clutch to rotate through the input shaft. S3: The C2 clutch drives the planet gears to rotate through the combined action of the ring gear and the planet carrier. S4: The planet gears drive the sun gear to rotate. S5: The sun gear drives the rotor shaft of motor two to store energy in the energy management system. S6: Motor one receives energy from the energy management system and drives the motor gear to rotate. S7: The motor gear drives the driven gear to rotate. At the same time, the C1 clutch drives the driven gear to rotate through the drive gear. S8: The driven gear drives the main reduction gear to rotate through the output shaft. S9: The main reduction gear drives the differential gear to rotate for power output.

[0011] The transmission method for the second gear in the parallel mode of a hybrid vehicle drive transmission system according to the present invention includes the following steps: S1: Engage both the C1 clutch and the B1 brake, disengage the C2 clutch, turn off motor two, and operate both the engine and motor one. S2: The engine drives the ring gear to rotate through the input shaft, planet carrier, and planet gears. S3: The ring gear drives the drive gear to rotate through the C1 clutch. S4: The drive gear drives the driven gear to rotate. At the same time, start motor one to drive the motor gear to rotate, and the motor gear drives the driven gear to rotate. S5: The driven gear drives the main reduction gear to rotate through the output shaft. S6: The main reduction gear drives the differential gear to rotate for power output.

[0012] The transmission method for the series-parallel mode of a hybrid vehicle drive transmission system according to the present invention includes the following steps: S1: Engage the C1 clutch, disengage both the C2 clutch and the B1 brake, and operate both the engine, motor two, and motor one. S2: Control the rotational speeds of the engine and motor two according to the operating characteristics of the planetary gear set. S3: The engine drives the planet gears through the input shaft and planet carrier. At the same time, motor two drives the sun gear to rotate through the rotor shaft, and the sun gear drives the planet gears to rotate. S4: The planet gears drive the ring gear to rotate. S5: The ring gear drives the drive gear to rotate through the C1 clutch; S6: The drive gear drives the driven gear to rotate; meanwhile, the first motor is started to drive the motor gear to rotate, and the motor gear drives the driven gear to rotate; S7: The driven gear drives the main reduction gear to rotate through the output shaft; S8: The main reduction gear drives the differential gear to rotate for power output.

[0013] The transmission method of the parking / generating electricity mode of a hybrid vehicle drive transmission system of the present invention includes the following steps: S1: Make the C2 clutch in the engaged state, make the C1 clutch and the B1 brake in the disengaged state, make the first motor in the non-working state, and make the engine and the second motor in the working state; S2: Start the engine through the second motor; S3: The engine drives the planet carrier and the C2 clutch to act together through the input shaft; S4: The C2 clutch drives the ring gear to rotate; S5: The ring gear and the planet carrier drive the planet gears to rotate together; S6: The planet gears drive the sun gear to rotate; S7: The sun gear drives the rotor shaft of the second motor to store energy in the energy management system.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The present invention innovatively constructs a multi-mode power system such as pure electric, series, parallel dual-gear, hybrid power split, and parking power generation by integrating a planetary gear train mechanism and a dual-motor cooperative control architecture, enabling the engine to always operate in the efficient range. With the power split characteristics of the planetary gear train and the motor speed regulation compensation, the fuel consumption is optimized under all working conditions. A compact actuator composed of a dual clutch and a brake is adopted. While retaining the advantages of the planetary gear train structure, the dual physical gear shift is realized through the logical combination of the clutches, taking into account the smoothness of continuously variable transmission and the improvement of the transmission efficiency in the high-speed range. The shift control strategy based on motor torque compensation ensures that there is no power interruption during the mode switching process, significantly improving the driving experience. And the modular integrated design reduces the number of components, reducing the system complexity and manufacturing cost at the same time. The parking power generation mode innovatively uses the planetary mechanism to realize the decoupled start of the engine-generator, improving the energy recovery efficiency, and finally forming a low-cost, lightweight, and high-efficiency hybrid solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the structural schematic diagram of the present invention; Figure 2 is the working schematic diagram of the pure electric mode of the present invention; Figure 3 It is a schematic diagram of the operation of the series mode of the present invention; Figure 4 It is a schematic diagram of the operation of the first gear of the parallel mode of the present invention; Figure 5 It is a schematic diagram of the operation of the second gear of the parallel mode of the present invention; Figure 6 It is a schematic diagram of the operation of the series-parallel mode; Figure 7 It is a schematic diagram of the operation of the parking / on-vehicle power generation mode. Specific embodiments

[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] A hybrid vehicle drive train system includes an engine 1, a second motor 3, a first motor 4, a C2 clutch 5, a C1 clutch 6, a B1 brake 7, an input shaft 8, a sun gear 9, a planet carrier 10, planet gears 11, a ring gear 12, a drive gear 14, a motor gear 18, and an output unit; the crankshaft of the engine 1 is coaxially and fixedly connected to the input end of the input shaft 8, the outside of the input shaft 8 is sleeved with a C2 clutch 5, a C1 clutch 6, and a drive gear 14, the input shaft 8 is fixedly connected to the inner hub of the C2 clutch 5, and the input shaft 8 is rotatably connected to the inner hub of the C1 clutch 6 and the drive gear 14 through bearings; the inner hub of the C2 clutch 5 is fixedly connected to one end of the planet carrier 10, the other end of the planet carrier 10 is provided with two planet gears 11, both of the two planet gears are meshed with the sun gear 9 and meshed with the ring gear 12, and the ring gear 12 is fixedly connected to the outer hub of the C2 clutch 5 and the outer hub of the C1 clutch 6; the C2 clutch 5 and the C1 clutch 6 share one outer hub or the C2 clutch 5 and the C1 clutch 6 respectively have their own outer hubs, and the two outer hubs are connected by splines or welding. The sun gear 9 is coaxially and fixedly connected to the rotor shaft 13 of the second motor 3, the outside of the rotor shaft 13 of the second motor 3 is coaxially and fixedly sleeved with the inner hub of the B1 brake 7, and the outer hub of the B1 brake 7 is integrally and fixedly connected to the inner wall of the housing; the inner hub of the C1 clutch 6 is fixedly connected to the drive gear 14, the rotor shaft of the first motor 4 is coaxially and fixedly connected to the motor gear 18, and both the drive gear 14 and the motor gear 18 are meshed with the output unit, and the output unit can be connected to the rear-end reduction mechanism or the vehicle rear axle transmission mechanism to transmit power to the vehicle wheels.

[0018] Further, the output unit includes an output shaft 15, a driven gear 16, a main reduction gear 17, and a differential gear 19; the driven gear 16 is meshed and connected with both the driving gear 14 and the motor gear 18, the driven gear 16 is coaxially and fixedly connected to the input end of the output shaft 15, the output end of the output shaft 15 is coaxially and fixedly connected to the main reduction gear 17, and the main reduction gear 17 is meshed and connected with the differential gear 19 to transmit power.

[0019] Further, a torsional damper 2 or a dual-mass flywheel is connected between the crankshaft of the engine 1 and the input shaft 8.

[0020] A transmission method for the pure electric mode of a hybrid vehicle drive transmission system according to the present invention, the method comprising the following steps: S1: Keep the C2 clutch 5, the C1 clutch 6, and the B1 brake 7 all in a disengaged state, keep the engine 1 and the motor two 3 both in a non-operating state, and keep the motor one 4 in an operating state; S2: Start the motor one 4 to provide power and drive the motor gear 18 to rotate; S3: The motor gear 18 drives the driven gear 16 to rotate; S4: The driven gear 16 drives the main reduction gear 17 to rotate through the output shaft 15; S5: The main reduction gear 17 drives the differential gear 19 to rotate for power output.

[0021] In this mode, the motor one 4 undergoes two-stage deceleration. The differential gear 19 can be fixedly connected to the differential assembly, and then through the vehicle's half shafts, the power reaches the vehicle's wheels. According to the vehicle's speed and torque requirements, the operating point of the motor one 4 is adjusted to meet the vehicle's needs, which can improve the vehicle's power performance. Since the motor one 4 itself has the operating characteristics of forward and reverse rotation, according to the vehicle's needs, the forward and reverse gear functions of the vehicle can be realized.

[0022] A transmission method for the series mode of a hybrid vehicle drive transmission system according to the present invention, the method comprising the following steps: S1: Keep the C2 clutch 5 in an engaged state, keep the C1 clutch 6 and the B1 brake 7 all in a disengaged state, and keep the engine 1, the motor two 3, and the motor one 4 all in an operating state; S2: The engine 1 drives the C2 clutch 5 to rotate through the input shaft 8; S3: The C2 clutch 5 drives the planet gear 11 to rotate through the combined action of the ring gear 12 and the planet carrier 10; S4: The planet gear 11 drives the sun gear 9 to rotate; S5: The sun gear 9 drives the rotor shaft 13 of the motor two 3 to rotate to store energy in the energy management system (for external devices); S6: The first motor 4 receives the energy from the energy management system to drive the motor gear 18 to rotate; S7: The motor gear 18 drives the driven gear 16 to rotate; S8: The driven gear 16 drives the main reduction gear 17 to rotate through the output shaft 15; S9: The main reduction gear 17 drives the differential gear 19 to rotate for power output.

[0023] The transmission method of the first gear in the parallel mode of a hybrid vehicle drive transmission system according to the present invention includes the following steps: S1: Make both the C2 clutch 5 and the C1 clutch 6 in the engaged state, make the B1 brake 7 in the disengaged state, and make the engine 1, the second motor 3 and the first motor 4 all in the working state; S2: The engine 1 drives the C2 clutch 5 and the C1 clutch 6 to rotate through the input shaft 8; S3: The C2 clutch 5 drives the planet gear 11 to rotate through the combined action of the ring gear 12 and the planet carrier 10; S4: The planet gear 11 drives the sun gear 9 to rotate; S5: The sun gear 9 drives the rotor shaft 13 of the second motor 3 to rotate to store energy in the energy management system (for external devices); S6: The first motor 4 receives the energy from the energy management system to drive the motor gear 18 to rotate; S7: The motor gear 18 drives the driven gear 16 to rotate. At the same time, the C1 clutch 6 drives the driven gear 16 to rotate through the drive gear 14; S8: The driven gear 16 drives the main reduction gear 17 to rotate through the output shaft 15; S9: The main reduction gear 17 drives the differential gear 19 to rotate for power output.

[0024] 0]The transmission method of the second gear in the parallel mode of a hybrid vehicle drive transmission system according to the present invention includes the following steps: S1: Make both the C1 clutch 6 and the B1 brake 7 in the engaged state, make the C2 clutch 5 in the disengaged state, make the second motor 3 in the non - working state, and make the engine 1 and the first motor 4 all in the working state; S2: Since the B1 brake 7 is in the engaged state, the rotor shaft 13 and the sun gear 9 of the second motor 3 are both locked and cannot rotate. Therefore, the engine 1 drives the ring gear 12 to rotate through the input shaft 8, the planet carrier 10 and the planet gear 11; S3: The ring gear 12 drives the drive gear 14 to rotate through the C1 clutch 6; S4: The driving gear 14 drives the driven gear 16 to rotate; at the same time, the starting motor 14 drives the motor gear 18 to rotate, and the motor gear 18 drives the driven gear 16 to rotate; S5: The driven gear 16 drives the main reduction gear 17 to rotate through the output shaft 15; S6: The main reduction gear 17 drives the differential gear 19 to rotate to output power.

[0025] The present invention provides a transmission method for a hybrid electric vehicle drive transmission system in a parallel-parallel mode (i.e., ECVT mode), the method comprising the following steps: S1: The C1 clutch 6 is engaged, the C2 clutch 5 and the B1 brake 7 are disengaged, and the engine 1, the motor 2 3 and the motor 1 4 are all in operation; S2: Control the speed of engine 1 and motor 2 3 according to the operating characteristics of the planetary gearbox; S3: Engine 1 drives planetary gears 11 via input shaft 8 and planetary carrier 10; simultaneously, motor 2 3 drives sun gear 9 via rotor shaft 13, and sun gear 9 drives planetary gears 11; S4: The planetary gear 11 drives the ring gear 12 to rotate, and the speed of the ring gear 12 can be known; S5: The ring gear 12 drives the drive gear 14 to rotate through the C1 clutch 6; S6: The driving gear 14 drives the driven gear 16 to rotate; at the same time, the starting motor 14 drives the motor gear 18 to rotate, and the motor gear 18 drives the driven gear 16 to rotate; S7: The driven gear 16 drives the main reduction gear 17 to rotate through the output shaft 15; S8: The main reduction gear 17 drives the differential gear 19 to rotate to output power.

[0026] The torque of engine 1 is divided into two parts. One part is transmitted to ring gear 12 through input shaft 8, planetary carrier 10 and planetary gear 11 in sequence; the other part of the torque is transmitted to sun gear 9 and motor 2 3 through planetary gear 11; since the speed of engine 1 is affected by the speed of motor 1 4 or motor 2 3, and the relative continuity relationship between engine 1 and vehicle speed is maintained, this power split mode is also called ECVT mode.

[0027] The present invention provides a method for driving a hybrid vehicle drive transmission system in a parking / stopping power generation mode, the method comprising the following steps: S1: The C2 clutch 5 is engaged, the C1 clutch 6 and the B1 brake 7 are both disengaged, the motor 1 4 is in a non-operating state, and the engine 1 and the motor 2 3 are both in an operating state; S2: Start engine 1 through motor 2 3; S3: The engine 1 drives the planet carrier 10 and the C2 clutch 5 to act together through the input shaft 8; S4: The C2 clutch 5 drives the ring gear 12 to rotate; S5: The ring gear 12 and the planet carrier 10 drive the planet gears 11 to rotate together; S6: The planet gears 11 drive the sun gear 9 to rotate; S7: The sun gear 9 drives the rotor shaft 13 of the second motor 3 to rotate, and stores energy into the energy management system (for external devices) to realize the battery charging function. According to the safety strategy, it is possible to select the parking / stopping power generation mode when the vehicle is in the P gear.

[0028] Table 1 Working mode table of the present invention Based on the planetary gear train structure and components of market - mature products, the present invention realizes a pure - electric mode, a series mode, a parallel mode with two fixed gears, and a hybrid power - split mode by adding two motors, two clutches and one brake. It has the advantages of simple structure, reasonable design and relatively low cost. According to the working conditions of the vehicle, different working modes are selected, and at the same time, the hybrid transmission system and the engine are in an efficient working area.

[0029] The pure - electric mode provides a way to rely on the battery to supply electrical energy to drive the motor to work alone when the engine does not provide power, and realizes the normal driving of the vehicle through the speed - changing transmission mechanism.

[0030] The series mode can realize the working mode of an extended - range electric vehicle according to the working requirements of the whole vehicle.

[0031] In the parallel mode, the engine can work alone, and the power distribution mechanism and the speed - changing transmission mechanism can transfer power normally to drive the whole vehicle, and at the same time, the motor can also be used to adjust the torque of the engine to improve the efficiency of the engine.

[0032] In the hybrid mode, the engine and the motor work together to drive the vehicle to run normally; by controlling the motor, the engine speed and torque operating points can be adjusted to reduce the engine fuel consumption. The hybrid power - split mode can effectively improve the engine working conditions, and combined with the two fixed gears in parallel, it can effectively solve the fuel economy and power performance of the vehicle in the whole working condition range, enable the engine to always be in an efficient area, and achieve excellent fuel consumption performance of the whole vehicle.

[0033] During the vehicle driving process, by switching among the above - mentioned working modes, the fuel consumption of the vehicle can be effectively saved. During the switching process of each mode, the motor can participate in driving, and there is no power interruption. The present invention improves the efficiency of the whole system, and has the advantages of low cost, light weight, simple structure, reasonable design and relatively low cost.

[0034] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other forms without departing from the spirit or essential characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent conditions of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0035] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hybrid vehicle drive transmission system, characterized in that: It includes an engine (1), a second motor (3), a first motor (4), a C2 clutch (5), a C1 clutch (6), a B1 brake (7), an input shaft (8), a sun gear (9), a planet carrier (10), planet gears (11), a ring gear (12), a drive gear (14), a motor gear (18), and an output unit; the crankshaft of the engine (1) is coaxially and fixedly connected to the input end of the input shaft (8), the C2 clutch (5), the C1 clutch (6), and the drive gear (14) are sleeved outside the input shaft (8), the input shaft (8) is fixedly connected to the inner hub of the C2 clutch (5), and the input shaft (8) is rotatably connected to the inner hub of the C1 clutch (6) and the drive gear (14); the inner hub of the C2 clutch (5) is fixedly connected to one end of the planet carrier (10), two planet gears (11) are installed at the other end of the planet carrier (10), both of the two planet gears (11) are meshed with the sun gear (9) and meshed with the ring gear (12), and the ring gear (12) is fixedly connected to the outer hub of the C2 clutch (5) and the outer hub of the C1 clutch (6); the sun gear (9) is coaxially and fixedly connected to the rotor shaft (13) of the second motor (3), the inner hub of the B1 brake (7) is coaxially and fixedly sleeved outside the rotor shaft (13) of the second motor (3), and the outer hub of the B1 brake (7) is fixedly connected to the inner wall of the housing; the inner hub of the C1 clutch (6) is fixedly connected to the drive gear (14), the rotor shaft of the first motor (4) is coaxially and fixedly connected to the motor gear (18), and both the drive gear (14) and the motor gear (18) are meshed with the output unit.

2. The drive transmission system of a hybrid vehicle according to claim 1, characterized in that: The output unit includes an output shaft (15), a driven gear (16), a main reduction gear (17), and a differential gear (19); the driven gear (16) is meshed with both the drive gear (14) and the motor gear (18), the driven gear (16) is coaxially and fixedly connected to the input end of the output shaft (15), the output end of the output shaft (15) is coaxially and fixedly connected to the main reduction gear (17), and the main reduction gear (17) is meshed with the differential gear (19).

3. A hybrid vehicle drive transmission system according to claim 1, characterized in that: A torsional damper (2) or a dual mass flywheel is connected between the crankshaft of the engine (1) and the input shaft (8).

4. A transmission method for the pure electric mode of a hybrid vehicle drive transmission system according to any one of claims 1-3, characterized in that: The method includes the following steps: S1: Keep the C2 clutch (5), the C1 clutch (6), and the B1 brake (7) in a disengaged state, keep the engine (1) and the second motor (3) in a non-operating state, and keep the first motor (4) in an operating state; S2: Start the first motor (4) to drive the motor gear (18) to rotate; S3: The motor gear (18) drives the driven gear (16) to rotate; S4: The driven gear (16) drives the main reduction gear (17) to rotate through the output shaft (15); S5: The main reduction gear (17) drives the differential gear (19) to rotate for power output.

5. A transmission method for the series mode of a hybrid vehicle drive transmission system according to any one of claims 1 to 3, characterized in that: The method includes the following steps: S1: Engage the C2 clutch (5), disengage both the C1 clutch (6) and the B1 brake (7), and operate both the engine (1), the second motor (3), and the first motor (4). S2: The engine (1) drives the C2 clutch (5) to rotate via the input shaft (8). S3: The C2 clutch (5) drives the planet gears (11) to rotate through the combined action of the ring gear (12) and the planet carrier (10). S4: The planet gears (11) drive the sun gear (9) to rotate. S5: The sun gear (9) drives the rotor shaft (13) of the second motor (3) to rotate and store energy in the energy management system. S6: The first motor (4) receives energy from the energy management system and drives the motor gear (18) to rotate. S7: The motor gear (18) drives the driven gear (16) to rotate. S8: The driven gear (16) drives the main reduction gear (17) to rotate via the output shaft (15). S9: The main reduction gear (17) drives the differential gear (19) to rotate for power output.

6. A transmission method for the first gear in the parallel mode of the hybrid vehicle drive transmission system according to any one of claims 1-3, characterized in that: The method comprises the following steps: S1: Engage both the C2 clutch (5) and the C1 clutch (6), disengage the B1 brake (7), and operate both the engine (1), the second motor (3), and the first motor (4). S2: The engine (1) drives the C2 clutch (5) and the C1 clutch (6) to rotate via the input shaft (8). S3: The C2 clutch (5) drives the planet gears (11) to rotate through the combined action of the ring gear (12) and the planet carrier (10). S4: The planet gears (11) drive the sun gear (9) to rotate. S5: The sun gear (9) drives the rotor shaft (13) of the second motor (3) to rotate and store energy in the energy management system. S6: The first motor (4) receives energy from the energy management system and drives the motor gear (18) to rotate. S7: The motor gear (18) drives the driven gear (16) to rotate. Meanwhile, the C1 clutch (6) drives the driven gear (16) to rotate via the drive gear (14). S8: The driven gear (16) drives the main reduction gear (17) to rotate via the output shaft (15). S9: The main reduction gear (17) drives the differential gear (19) to rotate for power output.

7. A transmission method for the second gear in the parallel mode of the hybrid vehicle drive train according to any one of claims 1-3, characterized in that: The method comprises the following steps: S1: Engage both the C1 clutch (6) and the B1 brake (7), disengage the C2 clutch (5), turn off the second motor (3), and operate both the engine (1) and the first motor (4). S2: The engine (1) drives the ring gear (12) to rotate via the input shaft (8), the planet carrier (10), and the planet gears (11). S3: The ring gear (12) drives the drive gear (14) to rotate via the C1 clutch (6). S4: The drive gear (14) drives the driven gear (16) to rotate. Meanwhile, start the first motor (4) to drive the motor gear (18) to rotate, and the motor gear (18) drives the driven gear (16) to rotate. S5: The driven gear (16) drives the main reduction gear (17) to rotate via the output shaft (15). S6: The main reduction gear (17) drives the differential gear (19) to rotate for power output.

8. A power-split mode transmission method for a hybrid vehicle drive train according to any one of claims 1-3, characterized in that: The method includes the following steps: S1: Engage the C1 clutch (6), disengage both the C2 clutch (5) and the B1 brake (7), and keep the engine (1), the second motor (3), and the first motor (4) all in working states. S2: Control the rotational speeds of the engine (1) and the second motor (3) according to the operating characteristics of the planetary gear set. S3: The engine (1) drives the planet gears (11) through the input shaft (8) and the planet carrier (10); meanwhile, the second motor (3) drives the sun gear (9) to rotate through the rotor shaft (13), and the sun gear (9) drives the planet gears (11) to rotate. S4: The planet gears (11) drive the ring gear (12) to rotate. S5: The ring gear (12) drives the drive gear (14) to rotate through the C1 clutch (6). S6: The drive gear (14) drives the driven gear (16) to rotate; meanwhile, start the first motor (4) to drive the motor gear (18) to rotate, and the motor gear (18) drives the driven gear (16) to rotate. S7: The driven gear (16) drives the main reduction gear (17) to rotate through the output shaft (15). S8: The main reduction gear (17) drives the differential gear (19) to rotate for power output.

9. A transmission method for the parking / stopping power generation mode of a hybrid vehicle drive transmission system according to any one of claims 1-3, characterized in that: The method includes the following steps: S1: Engage the C2 clutch (5), disengage both the C1 clutch (6) and the B1 brake (7), keep the first motor (4) in a non - working state, and keep the engine (1) and the second motor (3) all in working states. S2: Start the engine (1) through the second motor (3). S3: The engine (1) drives the planet carrier (10) and the C2 clutch (5) to act together through the input shaft (8). S4: The C2 clutch (5) drives the ring gear (12) to rotate. S5: The ring gear (12) and the planet carrier (10) jointly drive the planet gears (11) to rotate. S6: The planet gears (11) drive the sun gear (9) to rotate. S7: The sun gear (9) drives the rotor shaft (13) of the second motor (3) to rotate to store energy in the energy management system.

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