Output type power split hybrid tractor gearbox

Abstract

The invention relates to an output type power split hybrid tractor gearbox. An engine output shaft of an output type power split stepless speed change system is connected with a generator and a gear ring, and a rotating shaft of the generator is connected with the gear ring; a rotating shaft of the driving motor is connected with the sun gear, and the PTO output shaft is sleeved with a planetary frame hollow shaft which can rotate; a walking driving gear is connected to the planet carrier hollow shaft, a walking driven gear is connected to the walking output shaft, and the walking driving gear is constantly meshed with the walking driven gear; the four-wheel-drive driven gear is connected to the four-wheel-drive output shaft, and the four-wheel-drive driven gear is constantly meshed with the walking driven gear; a PTO output shaft of the engine direct-drive output system is connected with the output penetrating shaft, and a hydraulic driving gear of the hydraulic pump driving set is connected to the PTO output shaft. The walking stepless speed change control system is highly integrated, compact in structure and simple in transmission, walking stepless speed change is controlled, and independent and stable power performance of high-power power output, hydraulic pump drive and four-wheel drive output can be guaranteed.

Description

Technical Field

[0001] This invention relates to an output-type power-split hybrid tractor gearbox, belonging to the technical field of hybrid tractor gearboxes. Background Technology

[0002] Wheeled tractors are primarily used for field operations. With the rise of hybrid tractors, their advantages in energy saving and power performance have gradually made them a new direction for industry development. Currently, hybrid systems are an effective way to achieve energy conservation, emission reduction, and improved power performance in the tractor field. However, existing hybrid systems use an engine, generator, electric motor, and planetary gear mechanism. The engine drives the generator to convert some mechanical energy into electrical power, while the generator provides electrical energy to the electric motor, which then converts the electrical energy back into mechanical energy. Because existing hybrid technology solutions are mostly directly transplanted from automated vehicle platforms, they fail to fully consider the special needs of medium and high horsepower tractors for multiple power outputs.

[0003] As disclosed in CN117445645A, a continuously variable transmission (CVT) system for hybrid electric vehicles has an input drive connected to an engine, which is connected to the ring gear of a planetary gear mechanism. The electric motor is connected to a sun gear, which meshes with planetary gears. The planetary carrier shaft has a high-gear drive gear and a low-gear drive gear. The high-gear drive gear meshes with a high-gear driven gear, and the low-gear drive gear meshes with a low-gear driven gear. The high-gear driven gear or the low-gear driven gear is connected to the output shaft. Although this transmission system can achieve power splitting, it can only achieve continuously variable transmission for tractor walking systems.

[0004] Therefore, existing hybrid electric continuously variable transmission (CVT) systems for tractors mostly focus solely on the continuously variable transmission of the walking system, failing to efficiently integrate the walking system, PTO (Power Take-Off) mechanism, hydraulic pump drive, and four-wheel drive output. While using multiple motors to drive each power system separately achieves decoupled control, it results in a complex transmission structure, leading to high manufacturing costs, difficult spatial layout, and challenges in maintenance. Existing four-wheel drive systems mostly employ dedicated mechanical transfer cases, which not only occupy considerable space but also require significant modifications to the vehicle structure when integrating them with the CVT system, resulting in structural complexity and control difficulties. Thus, existing hybrid electric transmissions for tractors have always faced a contradiction between the increased power output functions and the complexity of the transmission system, preventing a reduction in transmission costs. Summary of the Invention

[0005] The purpose of this invention is to provide an output-type power split hybrid tractor gearbox, which is highly integrated, compact in structure, and simple in transmission. It can coordinate speed regulation and torque regulation to control the continuously variable transmission of travel, while also ensuring independent and stable power performance for high-power output, hydraulic pump drive, and four-wheel drive output.

[0006] The technical solution of the present invention to achieve the above objectives is: an output-type power-split hybrid tractor gearbox, characterized in that: it includes a gearbox housing, an output-type power-split continuously variable transmission system, and an engine direct drive output system; The output-type power split continuously variable transmission system includes an engine, a generator, a planetary gear set, a drive motor, a walking drive group, and a four-wheel drive transmission group. The generator, planetary gear set, drive motor, walking drive group, and four-wheel drive transmission group are housed in the gearbox housing. The engine has an output shaft and an output through-shaft disposed within the output shaft. The output shaft supports and passes through the gearbox housing and is connected to the input end of the generator to drive the generator. The output shaft is connected to the ring gear of the planetary gear set to distribute mechanical power to the planetary gear set. The generator provides electrical energy to the drive motor and is used to regulate the walking speed. The generator shaft is connected to the ring gear of the planetary gear set. The drive motor drives the sun gear of the planetary gear set and is used to adjust the walking torque. The shaft of the drive motor is connected to the sun gear of the planetary gear set. The sun gear meshes with the ring gear through the planetary gears. The planetary gears are mounted on the planet carrier. The hollow shaft of the sun gear passes through the drive motor and is mounted on the PTO output shaft, allowing relative rotation. The hollow shaft of the planet carrier is mounted on the PTO output shaft and can rotate relative to it. The aforementioned travel drive assembly includes a travel output shaft, a travel drive gear, and a travel driven gear. The travel output shaft is supported on the gearbox housing, the travel drive gear is connected to the hollow shaft of the planetary carrier, and the travel driven gear is connected to the travel output shaft. The travel drive gear and the travel driven gear are constantly meshed. The four-wheel drive power group includes a four-wheel drive output shaft and a four-wheel drive driven gear. The four-wheel drive output shaft is supported on the gearbox housing, and the four-wheel drive driven gear is connected to the four-wheel drive output shaft. The four-wheel drive driven gear is constantly meshed with the travel driven gear. The engine direct drive output system includes a PTO output shaft and a hydraulic pump drive assembly, which are installed inside the gearbox housing. The engine output through-shaft is connected to the PTO output shaft supported on the gearbox housing. The hydraulic pump drive assembly includes a hydraulic output shaft, a hydraulic drive gear, and a hydraulic driven gear. The hydraulic output shaft is supported on the gearbox housing. The hydraulic drive gear is connected to the PTO output shaft. The hydraulic driven gear is connected to the hydraulic output shaft. The hydraulic drive gear and the hydraulic driven gear are in constant mesh.

[0007] The output-type power-split hybrid tractor gearbox of this invention employs an output-type power-split continuously variable transmission (CVT) system and an engine direct-drive output system arranged in a common gearbox housing. The engine's output shaft is connected to the generator's input end and the ring gear of the planetary gear set, with the engine directly driving the generator. The drive motor is connected to the sun gear. Therefore, the power of the CVT system is input through the ring gear and output through the planetary carrier, achieving mechanical power splitting and motor power splitting. Speed ​​regulation by the generator and torque adjustment by the drive motor are used to coordinate the CVT control of the walking system. This provides assistance under different operating conditions when driving the vehicle, allowing the engine to continuously operate within its efficient speed range, significantly reducing fuel consumption and emissions. The four-drive power unit of this invention directly draws power from the walking output shaft, using a four-drive driven gear to distribute power to the four-drive output shaft. This eliminates the need for a dedicated four-drive power distribution box, optimizing the overall layout and space, greatly simplifying the internal structure of the gearbox, improving operational reliability, reducing control difficulty, and lowering manufacturing and operating costs. The engine direct-drive output system of this invention employs a PTO output shaft and a hydraulic pump drive assembly. Therefore, the engine's power is directly input to the PTO output shaft, providing driving force to each implement and achieving high-power output. Simultaneously, the hydraulic drive gear on the hydraulic pump drive assembly is connected to the PTO output shaft, and the hydraulic pump drive assembly provides power to each hydraulic pump through the hydraulic output shaft. Since both the PTO output shaft and the hydraulic pump drive assembly are directly driven by the engine, their output power is independent of the tractor's travel speed, ensuring the stability and abundance of power output under different operating conditions. The tractor gearbox of this invention completely eliminates the shift actuator, greatly simplifying the internal structure of the gearbox and reducing potential failure points. The tractor gearbox of this invention highly integrates four major functions—travel drive, four-wheel drive transmission, PTO output, and hydraulic pump power source—into a single gearbox housing, resulting in a compact layout and effective space utilization. This invention features an innovative structure integrating a direct-drive PTO engine with a hydraulic system, a generator for stepless speed regulation, and a four-wheel drive output group. By eliminating all shifting components, it simultaneously achieves stepless speed regulation, four-wheel drive force distribution, independent PTO output, and hydraulic output within the same gearbox housing. This completely resolves the fundamental contradiction between multi-functional output and the complexity of the transmission system, improves the overall reliability of the gearbox, significantly reduces manufacturing costs, ensures the stability and lifespan of each power source within the housing under various operating conditions, saves space in the overall machine layout, and provides a guarantee for the normal operation of the tractor. Attached Figure Description

[0008] The embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0009] Figure 1 This is a schematic diagram of the structure of an output-type power-split hybrid tractor gearbox according to the present invention.

[0010] Figure 2 This is a schematic diagram of another output-type power-split hybrid tractor gearbox of the present invention.

[0011] Wherein: 1—Engine, 1-1—Output shaft, 1-2—Output through shaft, 2—Generator, 3—Sun gear, 3-1—Hollow shaft of sun gear, 4—Planet gear, 5—Ring gear, 6—Planet carrier, 6-1—Hollow shaft of planet carrier, 6-2—Planet carrier support, 7—Drive motor, 8—Hydraulic driven gear, 9—Hydraulic output shaft, 10—Hydraulic drive gear, 11—PTO output shaft, 12—Travel drive gear, 13—Travel output shaft, 14—Travel driven gear, 15—Four-wheel drive driven gear, 16—Four-wheel drive output shaft, 17—Gearbox housing, 17-1—Rear end cover, 17-2—Second inner wall panel, 17-3—Lower bearing cover, 17-4—First inner wall panel, 18—Hydraulic guide wheel, 19—Guide wheel shaft. Detailed Implementation

[0012] See Figure 1 , 2 As shown, the present invention discloses an output-type power-split hybrid tractor gearbox, comprising a gearbox housing 17, an output-type power-split continuously variable transmission (CVT) system, and an engine direct-drive output system. See [link / reference]. Figure 1 , 2 As shown, the output-type power split continuously variable transmission system of the present invention includes an engine 1, a generator 2, a planetary gear set, a drive motor 7, a walking drive group and a four-wheel drive group. The generator 2, the planetary gear set, the drive motor 7, the walking drive group and the four-wheel drive group are disposed in the gearbox housing 17. The operating parameters of the engine 1, the generator 2 and the drive motor 7 can be controlled by the electronic control unit (ECU) of existing vehicles.

[0013] See Figure 1 , 2As shown, the engine 1 of the present invention has an output shaft 1-1 and an output through-shaft 1-2 disposed within the output shaft 1-1. The output shaft 1-1 supports and passes through the gearbox housing 17 and is connected to the input end of the generator 2 to drive the generator. The output shaft 1-1 and the output through-shaft 1-2 are connected to the engine flywheel. The output shaft 1-1 of the engine 1 is connected to the input end of the generator 2 and drives the generator 2 to work, so that the engine 1 and the generator 2 are directly connected. Therefore, after the engine 1 starts, it can drive the generator 2 to generate electricity. The generated electrical power is then transmitted to the drive motor 7 through the inverter, converting mechanical energy into electrical energy and transmitting it to the drive motor 7. See Figure 1 As shown, the output shaft 1-1 of the engine 1 of the present invention passes through the generator 2 and is connected to the ring gear 5 of the planetary gear set to divert mechanical power to the planetary gear set. The output shaft 1-1 is supported on the front wall of the gearbox housing by the front bearing. The engine 1 transmits part of the mechanical energy to the ring gear 5 to realize the diversion of mechanical power. The ring gear 5 is connected to the planet carrier 6 through the planetary gear 4, and the driving gear 12 is connected to the planet carrier 6 to transmit mechanical power to the driving gear 12 through the planet carrier 6.

[0014] See Figure 1 , 2 As shown, the generator 2 of this invention provides electrical energy to the drive motor 7 and is used to regulate the walking speed. In generator mode, the electrical energy generated by the generator 2 is directly transmitted to the drive motor 7 via an inverter, and excess electrical energy can be stored in a battery. The shaft of the generator 2 is connected to the ring gear 5 of the planetary gear set. When the generator 2 is working, its shaft drives the ring gear 5 to rotate. By controlling the speed and direction of the generator 2, the ratio of engine speed to wheel speed is continuously and steplessly changed, achieving continuous stepless speed regulation, so that the engine 1 always operates within the most economical and efficient speed range.

[0015] See Figure 1 , 2As shown, the drive motor 7 of this invention drives the sun gear 3 of the planetary gear set and is used to adjust the walking torque. The shaft of the drive motor 7 is connected to the sun gear 3 of the planetary gear set. The sun gear 3 meshes with the ring gear 5 through the planetary gears 4. The planetary gears 4 are mounted on the planet carrier 6. Three to four planetary gears 4 can be mounted on the planet carrier 6. The hollow shaft 3-1 of the sun gear 3 passes through the drive motor 7 and is mounted on the PTO output shaft 11, allowing relative rotation. The hollow shaft 6-1 of the planet carrier 6 is mounted on the PTO output shaft 11 and allows relative rotation. The drive motor 7 converts electrical energy back into mechanical power and drives the sun gear 3 to rotate, thereby providing the torque required for walking power through the planetary gears 4 and the planet carrier 6, and adjusting the torque under different working conditions. The walking power of this invention is input from the ring gear 5 and output from the planet carrier 6. Through the coordinated control of the speed regulation of the generator 2 and the torque regulation of the drive motor 7, the walking system continuously adjusts the speed, allowing the engine 1 to continuously operate in the high-efficiency speed range, significantly reducing fuel consumption and emissions.

[0016] See Figure 1 , 2 As shown, the walking drive assembly of the present invention includes a walking output shaft 13, a walking drive gear 12, and a walking driven gear 14. The walking output shaft 13 is supported on the gearbox housing 17. The walking drive gear 12 is connected to the hollow shaft 6-1 of the planetary carrier. Therefore, based on power splitting, the power is transmitted to the walking drive gear 12 through the planetary carrier 6. The walking driven gear 14 is connected to the walking output shaft 13. The walking drive gear 12 and the walking driven gear 14 are constantly meshed. The walking output shaft 13 outputs driving power and transmits the power to the wheels through the rear axle to drive the tractor to move.

[0017] See Figure 1 , 2 As shown, the four-drive power unit of the present invention includes a four-drive output shaft 16 and a four-drive driven gear 15. The four-drive output shaft 16 is supported on the gearbox housing 17, and the four-drive driven gear 15 is connected to the four-drive output shaft 16. The four-drive driven gear 15 is constantly meshed with the travel driven gear 14. The four-drive power of the present invention is directly taken from the travel output shaft 13, which greatly simplifies the internal structure of the gearbox, improves working reliability, reduces control difficulty, and reduces manufacturing and usage costs. The travel power is redistributed to the four-drive output shaft 16 to realize the output of four-drive power. The four-drive power is provided to the front wheels through the front axle, which can improve the economy of use and work efficiency, and ensure the continuous, efficient and stable operation of high-power machinery. The power output of continuously variable travel drive and the power output of four-drive are realized in the same housing, ensuring stability and life under various working conditions.

[0018] See Figure 1 , 2As shown, the engine direct drive output system of the present invention includes a PTO output shaft 11 and a hydraulic pump drive assembly. The PTO output shaft 11 and the hydraulic pump drive assembly are installed inside the gearbox housing 17. The output through-shaft 1-2 of the engine 1 is connected to the PTO output shaft 11 supported on the gearbox housing 17. The PTO output shaft is installed at the bearing hole of the rear end cover 17-1 of the gearbox housing through a rear bearing and extends out of the rear end cover 17-1. The rear end cover 17-1 is sealed and installed at the rear of the gearbox housing 17 by fasteners. The PTO output shaft can be connected to the hollow shaft of the sun gear and the hollow shaft of the planetary carrier through multiple integral or separate wear-resistant bushings or bearings. Therefore, the power of the engine 1 is directly transmitted to the PTO output shaft 11 to directly output power, which can realize high power output and ensure the stability of power output under different working conditions.

[0019] See Figure 1 As shown, the hydraulic pump drive assembly of the present invention includes a hydraulic output shaft 9, a hydraulic drive gear 10, and a hydraulic driven gear 8. The hydraulic output shaft 9 is supported on the gearbox housing 17. The hydraulic drive gear 10 is connected to the PTO output shaft 11, realizing direct connection between the hydraulic pump drive assembly and the engine, forming independent PTO output and hydraulic output. The hydraulic driven gear 8 is connected to the hydraulic output shaft 9. The hydraulic drive gear 10 and the hydraulic driven gear 8 are constantly meshed. Power is output to the hydraulic pump through the hydraulic output shaft 9, thereby realizing the hydraulic operation required for hydraulic lifting, steering, and agricultural implements. Within the same gearbox housing 17, each can form its own independent high-power power output and hydraulic pump drive, ensuring stability and lifespan under various working conditions.

[0020] See Figure 1 , 2 As shown, the gearbox housing 17 of this invention has a first inner wall plate 17-4 and a second inner wall plate 17-2 at the rear of the drive motor 7, dividing the gearbox housing 17 into a first housing, a second housing, and a third housing. The generator 2, the planetary gear set, and the drive motor 7 are sequentially and coaxially installed in the first housing. This invention places the planetary gear set between the generator 2 and the drive motor 7, which not only reduces the cost of the generator 2 and the drive motor 7 but also facilitates the installation of the planetary gear set with the generator 2 and the drive motor 7, resulting in better manufacturability. The walking drive group and the four-drive force group of this invention are installed in the second housing. The four-drive force is directly taken from the walking output shaft 13, resulting in a simple structure, convenient control, and reliable operation. See [link to relevant documentation]. Figure 1 , 2 As shown, the hydraulic pump drive unit of the present invention is installed in the third housing, and the hydraulic pump is powered by the hydraulic pump drive unit. The arrangement of each drive unit in the gearbox is optimized, which facilitates later maintenance and repair.

[0021] See Figure 1 , 2As shown, the planetary carrier 6 of the present invention is provided with a planetary carrier support 6-2 on the front side of the hollow planetary carrier shaft 6-1. The bearing hole on the planetary carrier support 6-2 is installed at the rear of the hollow sun gear shaft 3-1 through the first bearing. The planetary carrier 6 and the hollow planetary carrier shaft 6-1 are integrally formed or fixedly connected. Similarly, the sun gear 3 and the hollow sun gear shaft 3-1 are integrally formed or fixedly connected. The hollow planetary carrier shaft 6-1 is installed at the bearing hole of the first inner wall plate 17-4 and the bearing hole of the second inner wall plate 17-2 through the second bearing and the third bearing, respectively. The planetary carrier support 6-2 is not connected to the hollow planetary carrier shaft 6-1, so that one side of the planetary carrier 6 is supported on the hollow sun gear shaft 3-1 and the other side is supported on the two inner wall plates. Therefore, during the driving and power assistance process, the planetary carrier 6 has a better load-bearing capacity, improves the working reliability of the planetary gear set, and realizes various operations of high-horsepower tractors.

[0022] See Figure 1 , 2 As shown, the walking output shaft 13 of the present invention is installed in the bearing holes of the first inner wall plate 17-4 and the bearing holes of the rear end cover 17-1 respectively through the fourth bearing and the fifth bearing, and passes through the second inner wall plate 17-2. The walking output shaft 13 passes through the rear end cover 17-1, which has good assembly performance and maintenance performance.

[0023] See Figure 1 , 2 As shown, the first inner wall panel 17-4 of the present invention has an outer wall panel extending outward. The lower bearing cover 17-3 is sealed and installed on the outer wall panel by fasteners. The four-wheel drive output shaft 16 is installed on the lower bearing cover 17-3 and the second inner wall panel 17-2 respectively by the sixth bearing and the seventh bearing. The four-wheel drive output shaft 16 extends out of the lower bearing cover 17-3. Therefore, the four-wheel drive output shaft 16 extends out of the lower bearing cover 17-3 and connects to the front axle to realize four-wheel drive.

[0024] See Figure 1 As shown, the hydraulic output shaft 9 of this invention is installed in the bearing holes of the second inner wall plate 17-2 and the rear end bearing hole respectively via the eighth bearing and the ninth bearing, and the hydraulic output shaft 9 passes through the rear end cover 17-1 for convenient connection with the hydraulic pump. See Figure 2 As shown, another structure of the gearbox of the present invention is shown. The hydraulic pump drive group also has a hydraulic guide wheel 18 and a guide wheel shaft 19. The guide wheel shaft 19 is disposed between the PTO output shaft 11 and the hydraulic output shaft 9. The guide wheel shaft 19 is installed at the bearing holes of the second inner wall plate 17-2 and the rear end cover 17-1 respectively through the tenth bearing and the eleventh bearing. The hydraulic guide wheel 18 connected to the guide wheel shaft 19 is constantly meshed with the hydraulic drive gear 10 and the hydraulic driven gear 8, making the gearbox more compact.

[0025] When the output-type power-split hybrid tractor gearbox of the present invention is working, see Figure 1 , 2 As shown, the working process of the power-split continuously variable transmission (CVT) system is as follows: The flywheel of engine 1 drives generator 2 via output shaft 1-1, which in turn drives the ring gear 5 of the planetary gear set to rotate. This, in turn, drives the planetary carrier 6 to rotate via planetary gear 4. Part of the mechanical power of engine 1 is split to generator 2, and the other part is split to the ring gear 5. The drive gear 12 is connected to the planetary carrier 6, realizing the output of the split driving power. Generator 2 generates electricity, converting mechanical energy into electrical energy. This electrical energy is then rectified by an inverter and supplied to drive motor 7. The system is controlled by... The speed and direction of the generator 2 are controlled to achieve continuously variable transmission for walking; the shaft of the drive motor 7 is connected to the sun gear 3 to achieve torque regulation of walking power, converting electrical energy into mechanical energy and splitting the electrical power. The walking power is transmitted to the walking drive gear 12 through the planetary carrier 6, and then to the walking output shaft 13 through the walking driven gear 14. The walking output shaft 13 outputs the continuously variable driving power required by the wheels; the four-wheel drive driven gear 15 is constantly meshed with the walking driven gear 14, and the four-wheel drive force is output from the four-wheel drive output shaft 16 to the front wheels.

[0026] See Figure 1 , 2 As shown, the working process of the engine direct drive output system is as follows: the flywheel of engine 1 directly outputs power through the output through shaft 1-2 and PTO output shaft 11, while the hydraulic drive gear 10 is connected to the PTO output shaft 11. The hydraulic drive gear 10 meshes with the hydraulic driven gear 8 and outputs power to the hydraulic pump through the hydraulic output shaft 9, or the hydraulic drive gear 10 meshes with the hydraulic driven gear 8 through the hydraulic through wheel 18 to form independent PTO output and hydraulic output.

Claims

1. An output-type power-split hybrid tractor gearbox, characterized in that: This includes the gearbox housing, the output-type power-split continuously variable transmission system, and the engine direct-drive output system; The output-type power split continuously variable transmission system includes an engine, a generator, a planetary gear set, a drive motor, a walking drive group, and a four-wheel drive transmission group. The generator, planetary gear set, drive motor, walking drive group, and four-wheel drive transmission group are housed in the gearbox housing. The engine has an output shaft and an output through-shaft disposed within the output shaft. The output shaft supports and passes through the gearbox housing and is connected to the input end of the generator to drive the generator. The output shaft is connected to the ring gear of the planetary gear set to distribute mechanical power to the planetary gear set. The generator provides electrical energy to the drive motor and is used to regulate the walking speed. The generator shaft is connected to the ring gear of the planetary gear set. The drive motor drives the sun gear of the planetary gear set and is used to adjust the walking torque. The shaft of the drive motor is connected to the sun gear of the planetary gear set. The sun gear meshes with the ring gear through the planetary gears. The planetary gears are mounted on the planet carrier. The hollow shaft of the sun gear passes through the drive motor and is mounted on the PTO output shaft, allowing relative rotation. The hollow shaft of the planet carrier is mounted on the PTO output shaft and can rotate relative to it. The aforementioned travel drive assembly includes a travel output shaft, a travel drive gear, and a travel driven gear. The travel output shaft is supported on the gearbox housing, the travel drive gear is connected to the hollow shaft of the planetary carrier, and the travel driven gear is connected to the travel output shaft. The travel drive gear and the travel driven gear are constantly meshed. The four-wheel drive power group includes a four-wheel drive output shaft and a four-wheel drive driven gear. The four-wheel drive output shaft is supported on the gearbox housing, and the four-wheel drive driven gear is connected to the four-wheel drive output shaft. The four-wheel drive driven gear is constantly meshed with the travel driven gear. The engine direct drive output system includes a PTO output shaft and a hydraulic pump drive assembly, which are installed inside the gearbox housing. The engine output through-shaft is connected to the PTO output shaft supported on the gearbox housing. The hydraulic pump drive assembly includes a hydraulic output shaft, a hydraulic drive gear, and a hydraulic driven gear. The hydraulic output shaft is supported on the gearbox housing. The hydraulic drive gear is connected to the PTO output shaft. The hydraulic driven gear is connected to the hydraulic output shaft. The hydraulic drive gear and the hydraulic driven gear are in constant mesh.

2. The output-type power-split hybrid tractor gearbox according to claim 1, characterized in that: The gearbox housing has a first inner wall panel and a second inner wall panel in sequence at the rear of the drive motor, which divide the gearbox housing into a first housing, a second housing and a third housing. The generator, planetary gear set and drive motor are installed in sequence and coaxially in the first housing. The walking drive group and the four-drive force group are installed in the second housing. The hydraulic pump drive group is installed in the third housing.

3. The output-type power-split hybrid tractor gearbox according to claim 1 or 2, characterized in that: The planetary carrier is provided with a planetary carrier support seat on the front side of the hollow planetary carrier shaft. The bearing hole on the planetary carrier support seat is installed at the rear of the hollow sun gear shaft through a first bearing. The hollow planetary carrier shaft is installed at the bearing hole of the first inner wall plate and the bearing hole of the second inner wall plate through a second bearing and a third bearing, respectively.

4. The output-type power-split hybrid tractor gearbox according to claim 1 or 2, characterized in that: The walking output shaft is installed in the bearing holes of the first inner wall plate and the rear end cover respectively through the fourth bearing and the fifth bearing, and passes through the second inner wall plate. The walking output shaft extends out of the rear end cover.

5. The output-type power-split hybrid tractor gearbox according to claim 1 or above, characterized in that: The first inner wall panel has an outer wall panel extending outwards. The lower bearing cover is sealed and installed on the outer wall panel by fasteners. The four-wheel drive output shaft is installed on the lower bearing cover and the second inner wall panel respectively by the sixth bearing and the seventh bearing. The four-wheel drive output shaft passes through the lower bearing cover.

6. The output-type power-split hybrid tractor gearbox according to claim 1 or 2, characterized in that: The hydraulic output shaft is installed in the bearing holes of the second inner wall plate and the rear end cover respectively via the eighth and ninth bearings, and the hydraulic output shaft passes through the rear end cover; the hydraulic pump drive group also has a hydraulic guide wheel and a guide wheel shaft, the guide wheel shaft is set between the PTO output shaft and the hydraulic output shaft, the guide wheel shaft is installed in the bearing holes of the second inner wall plate and the rear end cover respectively via the tenth and eleventh bearings, and the hydraulic guide wheel connected to the guide wheel shaft is in constant mesh with the hydraulic drive gear and the hydraulic driven gear.

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