Heavy truck hybrid power system and driving method thereof

Abstract

According to the heavy truck hybrid power system, efficient starting and stopping, power generation and torque assistance are achieved through the auxiliary motor, strong electric driving force is achieved through the motor set, pure electric driving and energy recovery are supported, through cooperative control of the multiple motors, the working interval of the engine is dynamically optimized, idling loss is reduced, the power output efficiency is improved under the high-load scenes such as climbing and acceleration, and the power output efficiency is improved. Oil consumption of the heavy truck can be reduced, tail gas emission can be reduced, meanwhile, battery range extending is compatible, multi-mode dynamic driving of power generation, driving and energy recovery is achieved, low-speed pure electric driving and high-speed fuel economy are considered, flexible switching of a pure electric mode, a hybrid power mode, a range extending mode and a fuel direct driving mode can be formed, the road condition adaptability of the heavy truck is improved, and the service life of the heavy truck is prolonged. The method is suitable for multiple application scenes such as port short barge and trunk line logistics. The invention further provides a driving method of the heavy truck hybrid power system.

Description

Technical Field

[0001] The present invention relates to a heavy - duty truck hybrid system and a driving method thereof, belonging to the technical field of heavy - duty truck driving. Background Art

[0002] Traditional diesel heavy - duty trucks face challenges such as low energy consumption efficiency, excessive emissions of nitrogen oxides (NOx) and particulate matter during long - distance transportation. While pure - electric solutions are limited by battery costs, driving range, and charging facilities, and it is difficult to meet the requirements of heavy - duty truck heavy - load and long - distance operation in the short term. The hybrid system composed of a fuel engine and an electric drive mechanism applied in heavy - duty trucks combines the advantages of fuel and electric drive, can provide good fuel economy and low emissions, and is increasingly attracting market attention. The working conditions of heavy - duty commercial vehicles are relatively harsh, often requiring continuous operation for a long time, with a large load, which places more demanding requirements on the vehicle's power system, and the load of the power system is huge. Moreover, the road conditions for heavy - duty commercial vehicles are harsh and complex, and the working conditions are constantly changing rapidly. The battery needs to generate electricity and charge frequently, and its power requirements, stability, and durability requirements are all higher than those of passenger cars. However, current hybrid technologies mainly focus on passenger cars. Due to the significant differences in the actual working conditions between commercial vehicles and passenger cars, the application working conditions of heavy - duty commercial vehicles are extremely complex, and the working conditions of a single vehicle also vary greatly at different usage times. Therefore, the road - condition adaptability of hybrid systems in heavy - duty commercial vehicles remains to be improved.

[0003] In addition, in the existing heavy - duty truck hybrid system, the transmission relationship of the fuel engine determines that it can only assist the drive mechanism during driving and cannot drive the generator to generate electricity for electric - drive range extension. Only when the vehicle stops running can the engine drive the generator to generate electricity. This causes the battery power to approach the lower limit during vehicle operation, and there is no power generation supplement when the electric - drive ability is about to be lost. Summary of the Invention

[0004] The heavy - duty truck hybrid system provided by the present invention realizes multi - mode dynamic driving of power generation, driving, and energy recovery, takes into account low - speed pure - electric driving and high - speed fuel economy, can flexibly switch between pure - electric mode, hybrid mode, range - extender mode, and fuel direct - drive mode, improves the road - condition adaptability of heavy - duty trucks, and is suitable for meeting multiple application scenarios such as port short - haul and trunk - line logistics. The present invention also provides a driving method for a heavy - duty truck hybrid system.

[0005] To achieve the above object, the technical solution adopted by the present invention is: Heavy truck hybrid system, including a gearbox, an engine connected to the gearbox through a clutch, a drive shaft connected to the output end of the gearbox, and a double joint drive axle connected to the drive shaft, characterized in that: the gearbox includes an auxiliary motor, a transmission gear set connected to the auxiliary motor, a motor set composed of at least two motors, a power coupling set for coupling the power of multiple motors in the motor set, a shifting component with two-speed shifting function, and an output shaft meshing with the shifting component and coaxially connected to the drive shaft. The number of shifting components is two groups and they are symmetrically arranged on both sides of the output shaft. The power coupling set is connected to one group of shifting components, the transmission gear set is connected to the clutch, and a sliding gear sleeve corresponding to the other group of shifting components and axially slidable is installed on the transmission gear set. The transmission gear set is connected or disconnected from the other group of shifting components as the sliding gear sleeve axially slides.

[0006] Preferably, the shifting component includes a shifting shaft parallel to the output shaft, a rear intermediate shaft parallel to the shifting shaft, a shifting gear sleeve axially slidably assembled on the shifting shaft, a first gear driving gear rotatably installed on the shifting shaft, a second gear driving gear rotatably installed on the shifting shaft, a first gear driven gear fixed on the rear intermediate shaft and meshing with the first gear driving gear, a second gear driven gear fixed on the rear intermediate shaft and meshing with the second gear driving gear. The shifting gear sleeve is located between the first gear driving gear and the second gear driving gear. The shifting gear sleeve moves to the left to combine with the first gear driving gear and moves to the right to combine with the second gear driving gear. The rear intermediate shaft meshes with the output shaft. The shifting shaft of one group of shifting components is connected to the power coupling set, and a mating gear corresponding to the sliding gear sleeve is coaxially fixed on the shifting shaft of the other shifting component.

[0007] Preferably, the transmission gear set includes an input shaft one connected to the auxiliary motor, a constantly meshing shaft meshing with the input shaft one, and a support gear coaxially fixed on the constantly meshing shaft. The constantly meshing shaft is coaxially connected to the clutch, and the sliding gear sleeve is axially slidably assembled on the support gear.

[0008] Preferably, the sliding gear sleeve is located on the left side of the mating gear. The sliding gear sleeve slides to the right on the support gear to combine with the mating gear to connect the transmission gear set to the shifting component.

[0009] Preferably, the power coupling set includes input shafts two respectively connected to the motors in the motor set one by one, and constantly meshing gears two respectively meshing with multiple input shafts two. The constantly meshing gears two are coaxially fixed to the shifting shaft of one group of shifting components.

[0010] Preferably, the two rear intermediate shafts are symmetrically arranged on both sides of the output shaft. The shifting shafts are parallelly arranged outside the rear intermediate shafts. Output pinions are coaxially fixed on the rear intermediate shafts, and output large gears meshing with the output pinions are fixed on the output shaft.

[0011] Preferably, an electric eddy current retarder is coaxially installed on the drive shaft.

[0012] Preferably, the dual drive axle includes a first differential, a first half axle assembled on the half axle gear of the first differential, a second differential, a second half axle assembled on the half axle gear of the second differential, and a differential housing connecting shaft. The differential housing connecting shaft connects the differential housing of the first differential and the differential housing of the second differential. Drive wheels are mounted on both the first half axle and the second half axle.

[0013] The drive control method of the heavy-duty truck hybrid system described above is characterized in that the heavy-duty truck hybrid system has the following drive modes: Pure electric mode: The clutch is disengaged, and the sliding gear sleeve connects the transmission gear set to the shifting component. The auxiliary motor and the motor set drive together. Hybrid mode: The clutch is engaged, and the sliding gear sleeve connects the transmission gear set to the shifting component. The engine, the auxiliary motor and the motor set drive together, or the engine and the motor set drive together and the engine drives the auxiliary motor to generate electricity to charge the battery pack. Range extender mode: The clutch is engaged, and the sliding gear sleeve disconnects the transmission gear set from the shifting component. The motor set drives, and the engine drives the auxiliary motor to generate electricity to charge the battery pack. Fuel direct drive mode: The clutch is engaged, and the sliding gear sleeve connects the transmission gear set to the shifting component. Only the engine is used as the power source to drive. Energy recovery mode: The clutch is disengaged, and the sliding gear sleeve connects the transmission gear set to the shifting component. The drive wheels drive the auxiliary motor and the motor set in reverse to generate electricity to charge the battery pack.

[0014] Preferably, in the pure electric mode, range extender mode, hybrid mode and fuel direct drive mode, the shifting gear sleeve moves to the left to engage with the first gear driving gear to form first gear drive, or moves to the right to engage with the second gear driving gear to form second gear drive. In the energy recovery mode, the shifting gear sleeve moves to the left to engage with the first gear driving gear to form first gear reverse drive.

[0015] The beneficial effects of the invention are: The heavy truck hybrid system of the present invention includes an auxiliary motor, a motor group, and two shifting components in the transmission. The power coupling group couples and transmits the power of multiple motors in the motor group to one of the shifting components. The transmission gear group is respectively connected to the auxiliary motor and the clutch and is connected to the other shifting component through the movement of a sliding gear sleeve. Under heavy load conditions, if the battery pack has sufficient power, the clutch remains disengaged first. The sliding gear sleeve is connected to the shifting component, and the auxiliary motor and the motor group are used to drive together to increase the output torque, improve the starting and climbing power of the heavy truck, and meet the power requirements under heavy load conditions. When encountering extreme road conditions such as long-distance climbing or complex muddy road conditions, the clutch is engaged, and the engine is added to drive to form a hybrid drive, improve the torque density, ensure the passing performance of the vehicle, and help the vehicle get out of trouble in time. When the battery pack has insufficient power, the auxiliary motor drive is stopped, and the engine and the motor group are used to drive together, and the engine drives the auxiliary motor to generate electricity to charge the battery pack to maintain the battery pack power, so as to realize power generation by the engine during driving to increase the range of electric drive. Under light load conditions, if the battery pack has sufficient power, the clutch remains disengaged first, and the sliding gear sleeve is disconnected from the shifting component, and only the motor group is used to drive. When the battery pack has insufficient power, the clutch is engaged, and the engine drives the auxiliary motor to generate electricity to charge the battery pack to maintain the battery pack power, so as to realize power generation by the engine during driving to increase the range of electric drive. Under reverse drive conditions such as going down a long slope, the clutch is disengaged, the sliding gear sleeve is connected to the shifting component, the drive wheels reverse drive the double drive axle, and the double drive axle transmits the reverse driving force to the transmission to drive the auxiliary motor and the motor group to generate electricity to charge the battery pack, realizing energy recovery.

[0016] The auxiliary motor is used to achieve efficient start-stop, power generation, and torque assistance. The motor group is used to achieve strong electric driving force, and supports pure electric drive and energy recovery. Through the coordinated control of multiple motors, the working range of the engine is dynamically optimized, the idle loss is reduced, and the power output efficiency is improved in high-load scenarios such as climbing and accelerating. It can reduce the fuel consumption of heavy trucks, reduce exhaust emissions, and at the same time be compatible with battery range extension, realizing multi-mode dynamic drive of power generation, driving, and energy recovery, taking into account low-speed pure electric drive and high-speed fuel economy, and can form flexible switching between pure electric mode, hybrid mode, range extension mode, and fuel direct drive mode, improving the road condition adaptability of heavy trucks and being suitable for meeting multiple application scenarios such as port short-distance transportation and trunk line logistics. Brief Description of the Drawings

[0017] Figure 1 It is a transmission schematic diagram of the heavy truck hybrid system of the present invention.

[0018] Figure 2 It is a transmission schematic diagram of the connection between the engine and the transmission.

[0019] Figure 3 It is a transmission schematic diagram of the transmission when forming a first gear drive in pure electric mode.

[0020] Figure 4 It is a transmission schematic diagram of the gearbox when forming a second - gear drive in the pure - electric mode.

[0021] Figure 5 It is a transmission schematic diagram of the gearbox when forming a first - gear drive in the range - extender mode.

[0022] Figure 6 It is a transmission schematic diagram of the gearbox when forming a second - gear drive in the range - extender mode.

[0023] Figure 7 It is a transmission schematic diagram of the gearbox when forming a first - gear drive in the hybrid mode.

[0024] Figure 8 It is a transmission schematic diagram of the gearbox when forming a second - gear drive in the hybrid mode.

[0025] Figure 9 It is a transmission schematic diagram of the gearbox in the energy - recovery mode. Specific embodiments

[0026] The following combines Figures 1 to 9 to make a detailed description of the embodiments of the present invention.

[0027] A heavy - duty truck hybrid system includes a gearbox, an engine 2 connected to the gearbox through a clutch 1, a transmission shaft 3 connected to the output end of the gearbox, and a dual - drive axle 4 connected to the transmission shaft 3. It is characterized in that: the gearbox includes an auxiliary motor 5, a transmission gear set 6 connected to the auxiliary motor 5, a motor group 7 composed of at least two motors, a power coupling group 8 for coupling the power of multiple motors in the motor group, a shift component 9 with a two - speed shifting function, and an output shaft 10 meshing with the shift component 9 and coaxially connected to the transmission shaft. The number of the shift components 9 is two groups and they are symmetrically arranged on both sides of the output shaft 10. The power coupling group 8 is connected to one group of the shift components 9. The transmission gear set 6 is connected to the clutch 1. A sliding gear sleeve 61 corresponding to the other group of the shift components 9 and axially slidable is installed on the transmission gear set 6. The transmission gear set 6 is connected or disconnected from the other group of the shift components 9 along with the axial sliding of the sliding gear sleeve 61.

[0028] For the heavy-duty truck hybrid system described above, the gearbox includes an auxiliary motor 5, a motor group 7, and two shifting assemblies 9. The power coupling group 8 couples and transmits the power of multiple motors in the motor group 7 to one of the shifting assemblies 9. The transmission gear group 6 is respectively connected to the auxiliary motor 5 and the clutch 1 and is connected to the other shifting assembly 9 through the movement of the sliding gear sleeve 61. Under heavy-load conditions, if the battery pack has sufficient power, the clutch 1 remains disengaged first. The sliding gear sleeve 61 is connected to the shifting assembly 9, and the auxiliary motor 5 and the motor group 7 are used together to drive, increasing the output torque, enhancing the starting and climbing power of the heavy-duty truck, and meeting the power requirements under heavy-load conditions. When encountering extreme road conditions such as long-distance climbing or complex muddy road conditions, the clutch 1 is engaged, and the engine 2 is added to drive, forming a hybrid drive, increasing the torque density, ensuring the vehicle's passing performance, and helping the vehicle get out of trouble in time. When the battery pack has insufficient power, the auxiliary motor 5 stops driving, and the engine 2 and the motor group 7 are used together to drive, and the engine 2 drives the auxiliary motor 5 to generate electricity to charge the battery pack to maintain the battery pack's power, realizing power generation by the engine during driving to extend the electric drive range. Under light-load conditions, if the battery pack has sufficient power, the clutch 1 remains disengaged first. The sliding gear sleeve 61 is disconnected from the shifting assembly 9, and only the motor group 7 is used to drive. When the battery pack has insufficient power, the clutch 2 is engaged, and the engine 2 drives the auxiliary motor 5 to generate electricity to charge the battery pack to maintain the battery pack's power, realizing power generation by the engine during driving to extend the electric drive range. Under reverse drive conditions such as going down a long slope, the clutch 1 is disengaged, the sliding gear sleeve 61 is connected to the shifting assembly 9, the drive wheels reverse-drive the dual drive axle 4, and the dual drive axle 4 transmits the reverse driving force to the gearbox to drive the auxiliary motor 5 and the motor group 7 to generate electricity to charge the battery pack, realizing energy recovery. The auxiliary motor 5 is used to achieve efficient start-stop, power generation, and torque assistance. The motor group 7 is used to achieve strong electric driving force, and supports pure electric drive and energy recovery. Through the coordinated control of multiple motors, the working range of the engine 2 is dynamically optimized, reducing idle losses, and improving the power output efficiency in high-load scenarios such as climbing and accelerating, which can reduce the fuel consumption of the heavy-duty truck, reduce exhaust emissions, and at the same time be compatible with battery range extension, realizing multi-mode dynamic drive of power generation, driving, and energy recovery, taking into account low-speed pure electric drive and high-speed fuel economy, and enabling flexible switching between pure electric mode, hybrid mode, range-extended mode, and fuel direct drive mode, improving the road condition adaptability of the heavy-duty truck, and being suitable for meeting multiple application scenarios such as port short-haul and trunk logistics.

[0029] Among them, the shifting component 9 includes a shifting shaft 91 parallel to the output shaft 10, a rear intermediate shaft 92 parallel to the shifting shaft 91, a shifting gear sleeve 93 slidably assembled on the shifting shaft 91 along the axial direction, a first-gear driving gear 94 rotatably mounted on the shifting shaft 91, a second-gear driving gear 95 rotatably mounted on the shifting shaft 91, a first-gear driven gear 96 fixed on the rear intermediate shaft 92 and meshing with the first-gear driving gear 94, a second-gear driven gear 97 fixed on the rear intermediate shaft 91 and meshing with the second-gear driving gear 95. The shifting gear sleeve 93 is located between the first-gear driving gear 94 and the second-gear driving gear 95. The shifting gear sleeve 93 moves leftward to engage with the first-gear driving gear 94 and moves rightward to engage with the second-gear driving gear 95. The rear intermediate shaft 92 meshes with the output shaft 10. The shifting shaft 91 of one set of shifting components 9 is connected to the power coupling group 8, and a mating gear 98 corresponding to the sliding gear sleeve 61 is coaxially fixed on the shifting shaft 91 of the other shifting component 9. As shown in the figure, the two sets of shifting components are symmetrically arranged on both sides of the output shaft 10. One set of shifting components 9 is connected to the power coupling group to transmit the coupling power of the motor group 7 to the shifting components 9. A mating gear 98 corresponding to the sliding gear sleeve 61 is installed on the shifting shaft 91 of the other set of shifting components 9. In the initial state, the sliding gear sleeve 61 is not engaged with the mating gear 98. When it is necessary for the auxiliary motor and / or the engine to participate in driving, the sliding gear sleeve 61 is slid rightward to engage with the mating gear 98, so that the power of the auxiliary motor and / or the engine can be transmitted to the shifting shaft 91 through the transmission gear set. The first-gear driving gear 94 and the second-gear driving gear 95 are rotatably assembled on the shifting shaft 91. When the shifting gear sleeve 93 engages with the first-gear driving gear 94, the power on the shifting shaft 91 is transmitted to the rear intermediate shaft 92 through the first-gear driving gear 94 and the first-gear driven gear 96, and is transmitted from the rear intermediate shaft 92 to the output shaft 10, forming a first-gear power output to the transmission shaft 3. When the shifting gear sleeve 93 engages with the second-gear driving gear 95, the power on the shifting shaft 91 is transmitted to the rear intermediate shaft 92 through the second-gear driving gear 95 and the second-gear driven gear 97, and is transmitted from the rear intermediate shaft 92 to the output shaft 10, forming a second-gear power output to the transmission shaft 3.

[0030] Among them, the transmission gear set 6 includes a first input shaft 62 connected to the auxiliary motor 5, a constantly meshing shaft 63 meshing with the first input shaft 62, and a support gear 64 coaxially fixed on the constantly meshing shaft 63. The constantly meshing shaft 63 is coaxially connected to the clutch 1. The sliding gear sleeve 61 is axially slidably assembled on the support gear 64. Only when the sliding gear sleeve 61 is combined with the mating gear 98 can the transmission gear set 6 transmit power to the shifting assembly 9. Only when the clutch 1 is engaged and the sliding gear sleeve 61 is combined with the mating gear 98 can the power of the engine be transmitted to the shifting shaft 91 through the clutch 1. When the clutch is disengaged, the power of the engine 1 cannot be output. When the clutch is engaged and the sliding gear sleeve 61 is not combined with the mating gear 98, the power of the engine 1 can only be transmitted to the auxiliary motor 5 through the reduction gear shaft 6 to drive the auxiliary motor 5 to generate electricity and charge the battery pack.

[0031] Among them, the sliding gear sleeve 61 is located on the left side of the mating gear 98. The sliding gear sleeve 61 slides to the right on the support gear 64 and combines with the mating gear 98 to connect the transmission gear set 6 with the shifting assembly 9. The rightward sliding of the sliding gear sleeve 61 forms the connection between the transmission gear set 6 and the shifting assembly 9, and the leftward retraction forms the disconnection between the transmission gear set 6 and the shifting assembly 9. Through the sliding of the sliding gear sleeve 61 and the opening and closing of the clutch 1, flexible switching among the pure electric mode, hybrid mode, range extender mode, and fuel direct drive mode can be achieved, improving the timeliness of drive mode switching and the working condition adaptability.

[0032] Among them, the power coupling group 8 includes a second input shaft 81 connected to each motor in the motor group 7 one by one, and constantly meshing gears two 82 meshing with the multiple second input shafts 81 respectively. The constantly meshing gears two 82 are coaxially fixed to the shifting shaft 91 of a set of shifting assemblies 9. As shown in the figure, the motor group 7 consists of two motors. The two second input shafts 81 are respectively connected to the two motors, and the two second input shafts 81 are respectively connected to the constantly meshing gears two 82 to couple and transmit the power of the two motors to the shifting shaft 91.

[0033] Among them, the two rear intermediate shafts 92 are symmetrically arranged on both sides of the output shaft 10. The shifting shaft 91 is arranged in parallel on the outside of the rear intermediate shaft 82. An output pinion 99 is coaxially fixed on the rear intermediate shaft 92, and an output gear 11 meshing with the output pinion 99 is fixed on the output shaft 10. The power on the rear intermediate shaft 92 is transmitted to the output gear 11 through the output pinion 99, thereby driving the output shaft 10 to rotate. The power of the output shaft 10 is transmitted to the dual drive axle 4 through the transmission shaft 3.

[0034] Among them, an eddy current retarder 12 is coaxially installed on the transmission shaft 3. The eddy current retarder 12 realizes non-contact braking through the principle of electromagnetic induction and is installed on the transmission shaft 3 between the gearbox and the dual drive axle 4 to improve the braking efficiency.

[0035] Among them, the dual-link drive axle 4 includes a differential one 10, a half axle one 42 assembled on the side gear of the differential one 41, a differential two 43, a half axle two 44 assembled on the side gear of the differential two 43, and a differential case connecting shaft 45. The differential case connecting shaft 45 connects the differential case of the differential one 41 and the differential case of the differential two 43. Driving wheels 46 are assembled on both the half axle one 42 and the half axle two 44. The output shaft 10 drives the transmission shaft 3 to rotate. The transmission shaft 3 drives the differential transmission of the differential one 41, and drives the differential two 43 to rotate synchronously through the differential case connecting shaft 45, so that the half axle one 42 and the half axle two 44 drive the driving wheels 46 to rotate synchronously, and the differential of the left and right driving wheels 46 is formed through the differential one 41 and the differential two 43. The structure of the dual-link drive axle 4 is simple and reliable.

[0036] The driving control method of the heavy truck hybrid system described above is characterized in that: the heavy truck hybrid system has the following driving modes. Pure electric mode: The clutch 1 is disengaged, and the sliding gear sleeve 61 connects the transmission gear set 6 with the shift assembly 9. The auxiliary motor 5 and the motor set 7 drive together. Under heavy load conditions, if the battery pack has sufficient power, the pure electric mode is adopted for driving, and the engine does not participate in driving. Energy consumption is reduced under the condition of meeting the driving requirements. The power of the auxiliary motor 5 is transmitted to a group of shift assemblies 9 through the transmission gear set 6, and the power of the motor set 7 is transmitted to another group of shift assemblies 9 through the power coupling group 8. The power of the two groups of shift assemblies 9 is coupled and transmitted to the output shaft 10. The output shaft 10 drives the transmission shaft 3 to move, transmits the power to the dual-link drive axle 4, and drives the vehicle to move. Hybrid mode: The clutch 1 is closed, and the sliding gear sleeve 61 connects the transmission gear set 6 with the shift assembly 9. The engine 2, the auxiliary motor 5 and the motor set 7 drive together, or the engine 2 and the motor set 7 drive together and the engine 1 drives the auxiliary motor 5 to generate electricity for the battery pack to charge; under heavy load conditions, such as when encountering long uphill slopes or complex muddy road conditions, the hybrid mode is adopted for driving. The clutch 1 is closed, and the engine 2 participates in driving. The power of the engine 2 and the auxiliary motor 5 is transmitted to a group of shift assemblies 9 through the transmission gear set 6, and the power of the motor set 7 is transmitted to another group of shift assemblies 9 through the power coupling group 6. The power of the two groups of shift assemblies 9 is coupled and transmitted to the output shaft 10. The output shaft 10 drives the transmission shaft 3 to move, transmits the power to the dual-link drive axle 4, and drives the vehicle to move; in the hybrid mode, if the battery pack runs out of power due to continuous driving of the motor, the driving of the auxiliary motor 5 is stopped, and the engine 2 and the motor set 7 drive together and the engine 2 drives the auxiliary motor 5 to generate electricity to charge the battery pack to maintain the battery power, so as to realize the engine generating electricity to increase the range of the electric drive during driving. That is to say, in the hybrid mode, when the battery pack runs out of power, the engine 1 and the motor set 7 can drive together while driving the auxiliary motor 5 to generate electricity to charge the battery pack, preventing the battery pack from running out of power during driving, and realizing the range extension of the electric drive in the hybrid mode. Range-extending mode: Clutch 1 is closed. The sliding gear sleeve 61 disconnects the transmission gear set 6 from the shift assembly 9. Driven by the motor set 7, the engine 2 drives the auxiliary motor 5 to generate electricity to charge the battery pack. Under light load conditions, if the battery pack has sufficient power, clutch 1 remains disconnected first, disconnecting the sliding gear sleeve 61 from the shift assembly 9. Only the motor set 7 is used for driving. The power of the motor set 7 is transmitted to one set of shift assemblies 9 through the power coupling set 8. This set of shift assemblies 9 transmits the power to the output shaft. The output shaft 10 drives the transmission shaft 3 to move, transmitting the power to the dual-drive axle 4 to drive the vehicle. When the battery pack has insufficient power, clutch 2 is engaged, and the engine 2 drives the auxiliary motor 5 to generate electricity to charge the battery pack to maintain the battery power, realizing the range extension by using the engine to generate electricity during driving. In the range-extending mode, the engine 2 cannot transmit power to the shift assembly 9 and can only drive the auxiliary motor 5 to generate electricity to charge the battery pack. Fuel direct drive mode: Clutch 1 is closed. The sliding gear sleeve 61 connects the transmission gear set 6 to the shift assembly. Only the engine is used as the power source for driving. When the battery pack is depleted or the auxiliary motor and the motor set cannot work properly, the fuel direct drive mode is used to drive the vehicle. Energy recovery mode: Clutch 1 is disconnected. The sliding gear sleeve 61 connects the transmission gear set 6 to the shift assembly 9. The driving wheels drive the auxiliary motor 4 and the motor set 7 in reverse to generate electricity to charge the battery pack. Under reverse drive conditions such as going down a long slope, clutch 1 is disconnected, and the sliding gear sleeve 61 is connected to the shift assembly 9. The driving wheels drive the dual-drive axle 4 in reverse. The dual-drive axle 4 transmits the reverse driving force to the gearbox to drive the auxiliary motor 5 and the motor set 7 to generate electricity to charge the battery pack, realizing energy recovery.

[0037] Among them, in the pure electric mode, range-extending mode, hybrid mode, and fuel direct drive mode, the shift gear sleeve 93 moves to the left to engage with the first gear driving gear 94 to form first gear drive, or moves to the right to engage with the second gear driving gear 95 to form second gear drive. Through the shift adjustment of the shift assembly, two-gear power output is achieved in the pure electric mode, range-extending mode, hybrid mode, and fuel direct drive mode, dynamically optimizing the working range of the engine 2, reducing idle losses, and improving the power output efficiency in high-load scenarios such as climbing and accelerating. In the energy recovery mode, the shift gear sleeve 93 moves to the left to engage with the first gear driving gear 94 to form first gear reverse drive. In the energy recovery mode, no shift is required. The shift gear sleeve 93 is engaged with the first gear driving gear 94, and the reverse driving force of the driving wheels drives the auxiliary motor 5 and the motor set 7 to generate electricity to charge the battery pack to achieve energy recovery.

[0038] The technical solutions of the embodiments of the present invention have been completely described in conjunction with the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts shall fall within the scope of protection of the present invention.

Claims

1. A heavy-duty truck hybrid system, comprising a gearbox, an engine connected to the gearbox through a clutch, a drive shaft connected to the output end of the gearbox, and a dual-wheel drive axle connected to the drive shaft, characterized in that: The described transmission includes an auxiliary motor, a transmission gear set connected to the auxiliary motor, a motor set composed of at least two motors, a power coupling set that couples the power of multiple motors in the motor set, a shift component with a two-speed shifting function, and an output shaft that meshes with the shift component and is coaxially connected to the transmission shaft. The number of shift components is two groups and they are symmetrically arranged on both sides of the output shaft. The power coupling set is connected to one group of shift components, the transmission gear set is connected to the clutch, and a sliding gear sleeve corresponding to the other group of shift components and axially slidable is installed on the transmission gear set. The transmission gear set is connected or disconnected from the other group of shift components as the sliding gear sleeve axially slides.

2. The heavy-duty truck hybrid system according to claim 1, wherein: The described shift component includes a shift shaft parallel to the output shaft, a rear intermediate shaft parallel to the shift shaft, a shift gear sleeve axially slidably assembled on the shift shaft, a first-gear driving gear rotatably installed on the shift shaft, a second-gear driving gear rotatably installed on the shift shaft, a first-gear driven gear fixed on the rear intermediate shaft and meshing with the first-gear driving gear, a second-gear driven gear fixed on the rear intermediate shaft and meshing with the second-gear driving gear. The shift gear sleeve is located between the first-gear driving gear and the second-gear driving gear. The shift gear sleeve moves to the left to combine with the first-gear driving gear and moves to the right to combine with the second-gear driving gear. The rear intermediate shaft meshes with the output shaft. The shift shaft of one group of shift components is connected to the power coupling set, and a mating gear corresponding to the sliding gear sleeve is coaxially fixed on the shift shaft of the other shift component.

3. The heavy-duty truck hybrid system according to claim 2, characterized in that: The described transmission gear set includes an input shaft one connected to the auxiliary motor, a constantly meshing shaft meshing with the input shaft one, and a support gear coaxially fixed on the constantly meshing shaft. The constantly meshing shaft is coaxially connected to the clutch, and the sliding gear sleeve is axially slidably assembled on the support gear.

4. The heavy-duty truck hybrid system according to claim 3, wherein: The described sliding gear sleeve is located on the left side of the mating gear. The sliding gear sleeve slides to the right on the support gear to combine with the mating gear, connecting the transmission gear set to the shift component.

5. The heavy-duty truck hybrid system according to claim 2, wherein: The described power coupling set includes input shafts two respectively corresponding and connected to the motors in the motor set, and constantly meshing gears two respectively meshing with multiple input shafts two. The constantly meshing gears two are coaxially fixed to the shift shaft of one group of shift components.

6. The heavy-duty truck hybrid system according to claim 2, wherein: The two described rear intermediate shafts are symmetrically arranged on both sides of the output shaft. The shift shafts are parallelly arranged outside the rear intermediate shafts. Output pinions are coaxially fixed on the rear intermediate shafts, and output gears meshing with the output pinions are fixed on the output shaft.

7. The heavy-duty truck hybrid system according to claim 1, characterized in that: An eddy current retarder is coaxially installed on the transmission shaft.

8. The heavy-duty truck hybrid system according to claim 1, characterized in that: The described dual-drive axle includes a differential one, a half shaft one assembled on the side gear of the differential one, a differential two, a half shaft two assembled on the side gear of the differential two, and a differential case connecting shaft. The differential case connecting shaft connects the differential case of the differential one and the differential case of the differential two. Drive wheels are assembled on both the half shaft one and the half shaft two.

9. The drive control method of the heavy-duty truck hybrid system according to any one of claims 1 to 8, characterized in that: The described heavy-duty truck electric hybrid system includes the following driving modes. Pure electric mode: The clutch is disengaged, the sliding gear sleeve connects the transmission gear set to the shift component, and the auxiliary motor and the motor set drive together. Hybrid mode: The clutch is engaged, the sliding gear sleeve connects the transmission gear set to the shift component, and the engine, the auxiliary motor and the motor set drive together, or the engine and the motor set drive together and the engine drives the auxiliary motor to generate electricity to charge the battery pack. Range-extended mode: The clutch is closed, and the sliding gear sleeve disconnects the transmission gear set from the shift assembly. It is driven by the motor set, and the engine drives the auxiliary motor to generate electricity to charge the battery pack. Fuel direct drive mode: The clutch is closed, and the sliding gear sleeve connects the transmission gear set to the shift assembly. Only the engine is used as the power source for driving. Energy recovery mode: The clutch is disengaged, and the sliding gear sleeve connects the transmission gear set to the shift assembly. The drive wheels drive the auxiliary motor and the motor set in reverse to generate electricity to charge the battery pack.

10. The driving method of the heavy-duty truck hybrid system according to claim 9, wherein: In pure electric mode, range-extended mode, hybrid mode, and fuel direct drive mode, the shift gear sleeve moves to the left to engage with the first gear driving gear to form first gear drive, or moves to the right to engage with the second gear driving gear to form second gear drive. In energy recovery mode, the shift gear sleeve moves to the left to engage with the first gear driving gear to form first gear reverse drive.

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