Power split hybrid power transmission system and tractor

Abstract

The application relates to a power split hybrid transmission system and a tractor, which comprises an electronic continuously variable transmission, a first input shaft connected with a planetary carrier and penetrating a planetary gear mechanism composed of a sun gear, the planetary carrier and a ring gear, an engine connected with the first input shaft, a first motor connected with the sun gear and a ring gear shaft sleeved on the outer periphery of the first input shaft and in the ring gear, a double power coupling mechanism comprising a first intermediate transmission shaft, a second intermediate transmission shaft and an output shaft arranged in parallel and spaced apart, a middle shaft gear shifting mechanism connected between the first intermediate transmission shaft and the ring gear shaft, a second motor in driving connection with the second intermediate transmission shaft and a gear shifting mechanism connected between the first intermediate transmission shaft, the output shaft and the second intermediate transmission shaft. The application improves the fluency of the power transmission system, smoothly realizes power interruption-free gear shifting and improves the work efficiency and fuel economy of the tractor.

Description

Technical Field

[0001] This application relates to the field of tractor hybrid powertrain technology, and particularly to a power-split hybrid powertrain system and tractor. Background Technology

[0002] Tractor transmission systems need to adapt to different operating environments, such as tilling, harrowing, land preparation, cultivation, sowing, harvesting, and transportation. High-horsepower tractors can have dozens of gears. With the acceleration of agricultural modernization, the demand for efficient, intelligent, and environmentally friendly tractors is constantly increasing. Automatic gear shifting solves the problem of power interruption during gear shifting, is easy to operate, and can improve efficiency and productivity.

[0003] The mainstream technologies for tractor automatic transmissions include power shift automatic transmissions (PST) and hydraulic continuously variable transmissions (HMCVT). PST uses wet clutches to control gear shifting. It achieves uninterrupted gear shifting and reversing operations through a TCU and hydraulic control system. However, all shifting components in a power shift automatic transmission use wet clutches, resulting in high cost and complex control.

[0004] The hydraulic-mechanical continuously variable transmission (HMCVT) combines hydraulic and mechanical transmissions to achieve continuously variable speeds. CVTs overcome the inherent disadvantage of discontinuous gear ratios in stepped transmissions, offering advantages such as continuous gear ratios, smooth power transmission, good comfort, and strong adaptability. However, due to the application of a dual-flow hydraulic-mechanical transmission, CVTs have relatively lower transmission efficiency than power-shift transmissions, and their mechanical structure is more complex and costly.

[0005] Against the backdrop of electrification in the automotive industry, the trend towards electrification of tractors is accelerating. However, due to numerous limitations such as the scarcity of outdoor charging facilities, long battery charging times, and short operating hours, pure electric tractors are unlikely to achieve widespread adoption in the short term. Therefore, how to replace traditional hydraulic continuously variable transmissions (HMCVTs) with electric ones, improve the fuel economy of tractor power transmission systems, enable seamless gear shifting, simplify driver shifting operations, and enhance reliability has become an urgent problem to be solved. Summary of the Invention

[0006] This application provides a power-split hybrid power transmission system and a tractor to solve the problems of poor fuel economy and power interruption during gear shifts in the power transmission systems of tractors in the related art.

[0007] The first aspect of this application provides a power-split hybrid powertrain system, including:

[0008] An electronic continuously variable transmission (CVT) includes a planetary gear mechanism consisting of a sun gear, a planet carrier, and a ring gear, and a first input shaft connected to and passing through the planet carrier and the planetary gear mechanism. One end of the first input shaft is connected to an engine, a first motor is driven and connected to the sun gear, and a ring gear central shaft is connected to the ring gear and loosely fitted around the outer circumference of the first input shaft.

[0009] A dual-power coupling mechanism includes a first intermediate drive shaft, a second intermediate drive shaft, and an output shaft that are parallel to each other and spaced apart, and a gear shifting mechanism for the intermediate shaft connected between the first intermediate drive shaft and the gear ring intermediate shaft.

[0010] A second motor is connected to the second intermediate drive shaft, and a gear shifting mechanism is connected between the first intermediate drive shaft, the output shaft, and the second intermediate drive shaft.

[0011] In some embodiments: the first motor is connected to the sun gear via a second input shaft, the second input shaft is loosely fitted around the outer circumference of the first input shaft, and the first input shaft also serves as the PTO transmission output shaft for power output and passes through both sides of the planetary gear mechanism;

[0012] The first motor and the second input shaft are coaxially connected to each other, or the first motor is biasedly connected to the second input shaft through a first bias gear coupling mechanism, the first bias gear coupling mechanism including a first active bias gear connected to the first motor;

[0013] A first driven bias gear is connected to the second input shaft, and the diameter of the first driven bias gear is smaller than the diameter of the first driven bias gear and they mesh with each other.

[0014] In some embodiments: the second motor is biasedly connected to the second intermediate transmission shaft via a second bias gear coupling mechanism. The second bias gear coupling mechanism includes a third input shaft connected to the second motor, a second active bias gear and a second driven bias gear connected between the third input shaft and the second intermediate transmission shaft and meshing with each other. The second active bias gear is fixedly sleeved on the third input shaft, and the second driven bias gear is fixedly sleeved on the second intermediate transmission shaft.

[0015] In some embodiments: the intermediate shaft gear shifting mechanism includes a first intermediate gear pair, a second intermediate gear pair and a reverse gear pair connected between the intermediate shaft of the gear ring and the first intermediate transmission shaft, and arranged axially spaced in sequence;

[0016] A first shifting mechanism located between the first intermediate gear pair and the second intermediate gear pair for engaging or disengaging the first intermediate drive shaft from the first intermediate gear pair or the second intermediate gear pair, and a second shifting mechanism for engaging or disengaging the reverse gear pair from the first intermediate drive shaft or the gearbox housing.

[0017] In some embodiments: the first intermediate gear pair includes a first intermediate driving gear fixedly sleeved on the intermediate shaft of the gear ring, and a first intermediate driven gear loosely sleeved on the first intermediate transmission shaft;

[0018] The second intermediate gear pair includes a second intermediate driving gear fixedly sleeved on the intermediate shaft of the gear ring, and a second intermediate driven gear loosely sleeved on the first intermediate transmission shaft;

[0019] The reverse gear pair includes a reverse gear drive gear fixedly sleeved on the gear ring drive shaft, a reverse gear driven gear loosely sleeved on the first intermediate transmission shaft, and a reverse idler gear meshing between the reverse gear drive gear and the reverse gear driven gear;

[0020] The first shifting mechanism is fixed on the first intermediate drive shaft and located between the first intermediate driven gear and the second intermediate driven gear, and can selectively engage or disengage the first intermediate drive shaft from the first intermediate driven gear or the second intermediate driven gear; the second shifting mechanism is connected to the reverse intermediate driven gear and located between the reverse intermediate driven gear and the gearbox housing, and can selectively engage or disengage the reverse intermediate driven gear from the first intermediate drive shaft or the gearbox housing.

[0021] In some embodiments: the central shaft gear shifting mechanism includes a first central gear pair and a reverse central gear pair connected between the central shaft of the gear ring and the first intermediate transmission shaft and arranged axially spaced in sequence, and a first shifting mechanism located between the first central gear pair and the reverse central gear pair for engaging or disengaging the first central gear pair or the reverse central gear pair;

[0022] The first intermediate gear pair includes a first intermediate driving gear fixedly sleeved on the intermediate shaft of the gear ring, and a first intermediate driven gear loosely sleeved on the first intermediate transmission shaft;

[0023] The reverse gear pair includes a reverse gear drive gear fixedly sleeved on the gear ring drive shaft, a reverse gear driven gear loosely sleeved on the first intermediate transmission shaft, and a reverse idler gear meshing between the reverse gear drive gear and the reverse gear driven gear;

[0024] The first shifting mechanism is fixed on the first intermediate drive shaft and located between the first intermediate driven gear and the reverse intermediate driven gear, and can selectively engage or disengage the first intermediate drive shaft from the first intermediate driven gear or the reverse intermediate driven gear.

[0025] In some embodiments, the intermediate shaft gear shifting mechanism further includes an intermediate output gear that meshes with the first intermediate gear pair and is loosely fitted on the output shaft, and a second shifting mechanism that can selectively engage or disengage the intermediate output gear from the output shaft or the gearbox housing;

[0026] The intermediate output gear meshes with the first intermediate driven gear, and the second shifting mechanism is connected to the sleeve shaft of the intermediate output gear.

[0027] In some embodiments: the gear shifting mechanism includes a first intermediate driving gear and a third intermediate driving gear loosely fitted on the first intermediate transmission shaft, a first driven output gear and a second driven output gear fixed on the output shaft, and a second intermediate driving gear and a fourth intermediate driving gear loosely fitted on the second intermediate transmission shaft;

[0028] The first driven output gear meshes with both the first intermediate driving gear and the second intermediate driving gear. The second driven output gear meshes with both the third intermediate driving gear and the fourth intermediate driving gear. A third shifting mechanism is fixedly provided on the first intermediate transmission shaft to engage or disengage the first intermediate driving gear or the third intermediate driving gear from the first intermediate transmission shaft. A fourth shifting mechanism is fixedly provided on the second intermediate transmission shaft to engage or disengage the second intermediate driving gear or the fourth intermediate driving gear from the second intermediate transmission shaft.

[0029] In some embodiments, the gear shifting mechanism further includes a fifth intermediate driving gear and a sixth intermediate driving gear loosely fitted on the first intermediate transmission shaft, and a third driven output gear and a fourth driven output gear fixed on the output shaft;

[0030] The fifth intermediate driving gear meshes with the third driven output gear, and the sixth intermediate driving gear meshes with the fourth driven output gear. A fifth shifting mechanism is fixedly provided on the first intermediate transmission shaft to engage or disengage the fifth intermediate driving gear or the sixth intermediate driving gear from the first intermediate transmission shaft.

[0031] A second aspect of this application provides a tractor that includes the power-split hybrid powertrain system described in any of the above embodiments.

[0032] The beneficial effects of the technical solution provided in this application include:

[0033] This application provides a power-split hybrid power transmission system and a tractor. The power-split hybrid power transmission system of this application is equipped with an electronic continuously variable transmission (CVT), which includes a planetary gear mechanism consisting of a sun gear, a planetary carrier, and a ring gear; a first input shaft connected to the planetary carrier and passing through the planetary gear mechanism; one end of the first input shaft connected to an engine; a first motor driven by the sun gear; a ring gear intermediate shaft connected to the ring gear and loosely fitted around the outer circumference of the first input shaft; a dual power coupling mechanism, which includes a first intermediate drive shaft, a second intermediate drive shaft, and an output shaft arranged parallel to each other and spaced apart; an intermediate shaft gear shifting mechanism connected between the first intermediate drive shaft and the ring gear intermediate shaft; a second motor driven by the second intermediate drive shaft; and a gear shifting mechanism connected between the first intermediate drive shaft, the output shaft, and the second intermediate drive shaft.

[0034] Therefore, the power-split hybrid transmission system of this application can achieve power coupling of three power sources. The engine and the first motor are linked or connected in series via a planetary gear mechanism. The mechanically split power of the engine can selectively achieve efficient driving of multiple forward and reverse gears through the coupling linkage of the central shaft gear shifting mechanism and the gear shifting mechanism. The first motor can control the split of the mechanical input power of the engine. Part of the engine's power is converted into electrical energy by the first motor through electromechanical conversion, and the remaining mechanically split power is transmitted to the output shaft through the mechanical transmission path of the central shaft of the gear ring.

[0035] Furthermore, the second motor provides independent torque superposition or regenerative braking control for two gears via a gear shifting mechanism, significantly improving wheel-side drive traction. During gear shifting, the gear shifting mechanism enables switching between different power transmission paths, allowing for mutual power compensation between the engine and the second motor during gear shifting within the power transmission system. This improves the smoothness of the power transmission system, enabling seamless gear shifting without power interruption, thereby enhancing driving comfort, simplifying tractor operation procedures, and improving tractor operating efficiency and fuel economy. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the power-split hybrid powertrain system according to the first embodiment of this application;

[0038] Figure 2 This is a schematic diagram of the power-split hybrid powertrain system according to the second embodiment of this application;

[0039] Figure 3 This is a schematic diagram of the power-split hybrid powertrain system according to the third embodiment of this application;

[0040] Figure 4 This is a schematic diagram of the power-split hybrid powertrain system according to the fourth embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the power-split hybrid powertrain system according to the fifth embodiment of this application;

[0042] Figure 6 This is a schematic diagram of the power split hybrid powertrain system according to the sixth embodiment of this application.

[0043] Figure 7 This is a schematic diagram of the power-split hybrid powertrain system according to the seventh embodiment of this application;

[0044] Figure 8 This is a schematic diagram of the power split hybrid powertrain system according to the eighth embodiment of this application.

[0045] Figure label:

[0046] 1. Engine; 2. First motor; 3. Second motor; 4. Planetary gear mechanism; 4S. Sun gear; 4C. Planet carrier; 4R. Ring gear;

[0047] 10. First input shaft; 20. Second input shaft; 21. First driving bias gear; 22. First driven bias gear; 30. Third input shaft; 31. Second driving bias gear; 32. Second driven bias gear;

[0048] 40. Gear ring drive shaft; 41. First drive gear; 42. Second drive gear; 43. Reverse drive gear; 43R. Reverse idler gear;

[0049] 50. First intermediate drive shaft; 51. First intermediate driven gear; 52. Second intermediate driven gear; 53. Reverse driven gear; 54. First intermediate drive gear; 55. Third intermediate drive gear; 56. Fifth intermediate drive gear; 57. Sixth intermediate drive gear;

[0050] 60. Second intermediate drive shaft; 61. Second intermediate drive gear; 62. Fourth intermediate drive gear; 70. Output shaft; 71. First driven output gear; 72. Second driven output gear; 73. Third driven output gear; 74. Fourth driven output gear;

[0051] K1, First shifting mechanism; K2, Second shifting mechanism; K3, Third shifting mechanism; K4, Fourth shifting mechanism; K5, Fifth shifting mechanism; 100, Central shaft gear shifting mechanism; 200, Gear shifting mechanism. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] This application provides a power-split hybrid power transmission system and a tractor, which can solve the problems of poor fuel economy and power interruption during gear shifts in the power transmission system of tractors in the related art.

[0054] See Figures 1 to 8 As shown, the first aspect of this application provides a power-split hybrid powertrain system, including:

[0055] The electronic continuously variable transmission (E-CVT) includes a planetary gear mechanism 4 consisting of a sun gear 4S, a planet carrier 4C, and a ring gear 4R. Multiple planetary gears mesh between the sun gear 4S and the ring gear 4R and are rotatably connected to the planet carrier 4C. It also includes a first input shaft 10 connected to the planet carrier 4C and passing through the planetary gear mechanism 4. One end of the first input shaft 10 is connected to an engine 1, a first motor 2 that is drively connected to the sun gear 4S, and a ring gear transfer shaft 40 connected to the ring gear 4R and loosely fitted around the outer circumference of the first input shaft 10.

[0056] Engine 1 is connected to planetary carrier 4C via first input shaft 10, and first motor 2 is connected to sun gear 4S via second input shaft 20. Engine 1 and first motor 2 can be selectively linked or connected in series via planetary gear mechanism 4. The gear ring's central shaft 40 is connected to the output end of gear ring 4R. When gear ring 4R is not locked, first motor 2 can control the mechanical input power of engine 1. Part of the power of engine 1 is converted into electrical energy by first motor 2 through electromechanical conversion, and the remaining mechanically split power is transmitted through the mechanical transmission path of gear ring's central shaft 40. Alternatively, as needed, second gear shifting mechanism K2 can selectively lock gear ring's central shaft 40, allowing engine 1 to drive first motor 2 to generate electricity via the series linkage of planetary gear mechanism 4. First motor 2 then charges the battery to supplement electrical energy.

[0057] Furthermore, the first input shaft 10 also serves as the PTO drive shaft for the engine 1, transmitting a portion of the engine 1's power to other agricultural machinery loads, such as rotary tillers, harvesters, and generators, during operation. One end of the first input shaft 10 is connected to the output shaft of the engine 1, and the other end is connected to and passes through the planetary carrier 4C of the planetary gear mechanism 4. The second input shaft 20 and the gear ring intermediate shaft 40 are hollow shafts respectively fitted around the outer periphery of both sides of the first input shaft 10. The PTO output end of the first input shaft 10 is connected to an external PTO transmission device, and according to the tractor's functional settings, transmits a portion of the engine 1's power to the PTO load devices through the PTO transmission device to meet operational needs such as tilling, sowing, harvesting, and irrigation.

[0058] A dual-power coupling mechanism includes a first intermediate drive shaft 50, a second intermediate drive shaft 60, and an output shaft 70, which are parallel to each other and spaced apart. A gear shifting mechanism 100, connected between the first intermediate drive shaft 50, the gear ring intermediate shaft 40, and the output shaft 70, has one or two forward gears and one reverse gear. A second motor 3 is driven by the second intermediate drive shaft 60, and a gear shifting mechanism 200 is connected between the first intermediate drive shaft 50, the output shaft 70, and the first intermediate drive shaft 50.

[0059] The intermediate shaft gear shifting mechanism 100 is linked with the first intermediate drive shaft 50 or the output shaft 70, selectively transmitting the mechanical power of the engine 1 to the first intermediate drive shaft 50 in one or two forward gears and one reverse gear, or directly to the output shaft 70 in one forward gear. It can also selectively realize the series linkage power generation function between the engine 1 and the first motor 2 in the planetary gear mechanism 4. The first intermediate drive shaft 50 can selectively be linked with the gear shifting mechanism 200, thereby selectively realizing the transmission of multiple gear positions of the power input to the first intermediate drive shaft 50, that is, ultimately selectively realizing the transmission of the mechanical power of the engine 1 to the output shaft 70 in multiple forward gears and multiple reverse gears.

[0060] Furthermore, the second motor 3 is connected to the second intermediate drive shaft 60, which can selectively engage with the gear shifting mechanism 200, thereby selectively transmitting the power input of the second motor 3 to the output shaft 70 according to two independent transmission gears. When the tractor decelerates or brakes, the second motor 3 functions as a generator, converting the tractor's kinetic energy into electrical energy and storing it in the battery, achieving energy recovery and further improving energy efficiency. During tractor operation, the engine 1, the first motor 2, and the second motor 3 can work collaboratively according to different operating conditions.

[0061] When the tractor's power battery has sufficient charge, the second motor 3 can work independently to drive the tractor forward. At this time, the engine 1 does not participate in traction drive, and the tractor relies on the battery's power to drive, achieving zero emissions and low energy consumption.

[0062] When the tractor's PTO power output is activated or the traction drive load demand is high, engine 1 directly transmits part of its power to the PTO driveshaft output, while another part of the engine power is transmitted to the planetary carrier 4C as traction drive power and split-generation power. At this time, the first motor 2 can act as a split-generation motor, coordinating and distributing a portion of the power input from engine 1 to the traction drive power and split-generation power according to the tractor's driving needs, thus achieving continuously variable transmission (CVT) of engine 1 across multiple gears. The first motor 2 can also charge the battery as needed to replenish electrical energy. In this process, engine 1 alone or in conjunction with the second motor 3 provides driving power to the tractor, realizing hybrid power drive and improving power performance and fuel economy.

[0063] Since the mechanical power distribution path of engine 1 and the power transmission path of the second motor 3 are independent, during the gear shifting process of engine 1 through the intermediate shaft gear shifting mechanism 100 and the gear shifting mechanism 200, the second motor 3 can maintain power drive through the intermediate transmission shaft 60 and the gear shifting mechanism 200 in gear linkage, thereby realizing the gear shifting of engine 1 without power interruption; conversely, when the second motor 3 is disengaged through the intermediate transmission shaft 60 to achieve gear shifting control, engine 1 is maintained in gear drive through the intermediate shaft gear shifting mechanism 100 and the gear shifting mechanism 200, thereby realizing the gear shifting control of the second motor 3 without power interruption.

[0064] The power-split hybrid transmission system of this application embodiment can achieve power coupling of three power sources. The engine 1 and the first motor 2 are linked or connected in series via a planetary gear mechanism 4. The mechanically split power of the engine 1 can selectively achieve efficient driving of multiple forward and reverse gears through the coupling linkage of the central shaft gear shifting mechanism 100 and the gear shifting mechanism 200. The first motor 2 can control the split of the mechanical input power of the engine 1, excluding the PTO power output, through the planetary gear mechanism 4. Part of the power of the engine 1 is converted into electrical energy by the first motor 2 through electromechanical conversion, and the remaining mechanically split power is transmitted to the output shaft 70 through the mechanical transmission path of the central shaft 40 of the gear ring.

[0065] Furthermore, the second motor 3 provides independent torque superposition or regenerative braking control for two gears via the gear shifting mechanism 200, which can significantly improve wheel-side drive traction. During gear shifting, the gear shifting mechanism 200 enables switching between different power transmission paths, allowing for mutual power compensation between the engine 1 and the second motor 3 during gear shifting in the power transmission system. This improves the smoothness of the power transmission system, enabling seamless gear shifting without power interruption, thereby improving driving comfort, simplifying tractor operation procedures, and enhancing tractor operating efficiency and fuel economy.

[0066] In some alternative embodiments, see Figures 1 to 8 As shown, this application embodiment provides a power-split hybrid powertrain system. In this system, the engine 1 is directly connected to the planetary carrier 4C via a first input shaft 10, and a clutch is eliminated between the engine 1 and the planetary gear mechanism 4. The first motor 2 is connected to the sun gear 4S via a second input shaft 20, which is loosely fitted around the outer periphery of the first input shaft 10.

[0067] The first input shaft 10, the second input shaft 20, the planetary gear mechanism 4, and the gear ring intermediate shaft 40 are arranged along the same axial direction. The first input shaft 10 connects the engine 1 and the planetary carrier 4C. The second input shaft 20 is connected to the sun gear 4S and is hollowly fitted on one side of the first input shaft 10. The first motor 2 is linked to the sun gear 4S through the second input shaft 20 and splits part of the input power of the engine 1. The mechanical linkage power is transmitted through the mechanical transmission path of the gear ring intermediate shaft 40 connected to the gear ring 4R. In addition, the first input shaft 10 also serves as the PTO power output transmission shaft, passing through both ends of the planetary gear mechanism 4, and the gear ring intermediate shaft 40 is hollowly fitted on the other side of the first input shaft 10.

[0068] In some alternative embodiments, see Figure 1 , Figure 3 and Figure 5 As shown, this application embodiment provides a power-split hybrid powertrain system. The first motor 2 of this power-split hybrid powertrain system is biasedly connected to the second input shaft 20 via a first bias gear coupling mechanism. The first bias gear coupling mechanism includes a first driving bias gear 21 connected to the first motor 2 and a first driven bias gear 22 connected to the second input shaft 20. The diameter of the first driving bias gear 21 is smaller than the diameter of the first driven bias gear 22, and they mesh with each other.

[0069] In this embodiment, the first motor 2 is biasedly connected to the second input shaft 20 via a first bias gear coupling mechanism formed by the meshing of a first driving bias gear 21 and a first driven bias gear 22. The second input shaft 20 is loosely fitted outside the first input shaft 10 and directly connected to the sun gear 4S. The first driving bias gear 21 and the first driven bias gear 22 can bias the first motor 2 and the engine 1, which facilitates the system space arrangement. Furthermore, the smaller diameter of the first driving bias gear 21 compared to the first driven bias gear 22 can increase the rotational speed of the first motor 2 and enhance torque transmission.

[0070] In some alternative embodiments, see Figure 2 , Figure 4 , Figures 6 to 8 As shown, this application embodiment provides a power-split hybrid power transmission system, in which the first motor 2 and the second input shaft 20 are coaxially connected. This embodiment eliminates the first bias gear coupling mechanism formed by the meshing of the first driving bias gear 21 and the first driven bias gear 22 in the above embodiments. In this embodiment, the output shaft of the first motor 2 is directly connected to the second input shaft 20, thereby simplifying the transmission system structure of the above embodiments.

[0071] In some alternative embodiments, see Figures 1 to 8As shown, this application embodiment provides a power-split hybrid powertrain system. The second motor 3 of the power-split hybrid powertrain system is biasedly connected to the second intermediate drive shaft 60 via a second bias gear coupling mechanism. The second bias gear coupling mechanism includes a third input shaft 30 connected to the second motor 3, a second driving bias gear 31 and a second driven bias gear 32 connected between the third input shaft 30 and the second intermediate drive shaft 60 and meshing with each other.

[0072] In this embodiment, the second motor 3 is biasedly connected to the second intermediate transmission shaft 60 via a second bias gear coupling mechanism formed by the meshing of a second driving bias gear 31 and a second driven bias gear 32. The second driving bias gear 31 and the second driven bias gear 32 can bias the second motor 3 and the engine 1, facilitating system space arrangement. Furthermore, the smaller diameter of the second driving bias gear 31 compared to the second driven bias gear 32 enables single-stage speed reduction between the second motor 3 and the second intermediate transmission shaft 60, increasing torque transmission.

[0073] In some alternative embodiments, see Figures 1 to 4 As shown, this application embodiment provides a power split hybrid power transmission system. The transfer shaft gear shifting mechanism 100 of the power split hybrid power transmission system includes a first transfer gear pair, a second transfer gear pair and a reverse transfer gear pair connected between the gear ring transfer shaft 40 and the first intermediate transmission shaft 50 and arranged axially spaced in sequence.

[0074] The intermediate gear shifting mechanism 100 also includes a first shifting mechanism K1 located between the first and second intermediate gear pairs for engaging or disengaging either the first or second intermediate gear pair, and a second shifting mechanism K2 for engaging or disengaging the reverse intermediate gear pair or the gearbox housing. The first shifting mechanism K1 achieves switching between two adjacent consecutive gears by engaging or disengaging the first and second intermediate gear pairs. The second shifting mechanism K2 achieves switching between the reverse gear and the series-linked power generation by engaging or disengaging the reverse intermediate gear pair or the gearbox housing.

[0075] In some alternative embodiments, see Figures 1 to 4 As shown in the figure, this application embodiment provides a power-split hybrid powertrain system. The first intermediate gear pair of the power-split hybrid powertrain system includes a first intermediate drive gear 41 fixedly sleeved on the intermediate shaft 40 of the gear ring, and a first driven gear 51 loosely sleeved on the first intermediate transmission shaft 50. The second intermediate gear pair includes a second drive gear 42 fixedly sleeved on the intermediate shaft 40 of the gear ring, and a second driven gear 52 loosely sleeved on the first intermediate transmission shaft 50.

[0076] The reverse gear pair includes a reverse gear drive gear 43 fixed on the gear ring drive shaft 40, a reverse gear driven gear 53 loosely fitted on the first intermediate drive shaft 50, and a reverse idler gear 43R meshing between the reverse gear drive gear 43 and the reverse gear driven gear 53. A first shifting mechanism K1 is fixed on the first intermediate drive shaft 50 and located between the first driven gear 51 and the second driven gear 52. A second shifting mechanism K2 is fixedly connected to the third driven gear 51 and located between the third driven gear 51 and the gearbox housing.

[0077] The intermediate gear shifting mechanism 100 of this application embodiment is constructed as a three-speed gear assembly transmission mechanism, wherein the first intermediate drive gear 41, the second intermediate drive gear 42, and the reverse intermediate drive gear 43 are fixed on the gear ring intermediate shaft 40. The first intermediate driven gear 51, the second intermediate driven gear 52, and the reverse intermediate driven gear 53 are loosely fitted on the first intermediate transmission shaft 50. The first intermediate drive gear 41 and the second intermediate drive gear 42 mesh with the first intermediate driven gear 51 and the second intermediate driven gear 52, respectively, while the reverse intermediate drive gear 43 and the reverse intermediate driven gear 53 simultaneously mesh with the reverse idler gear 43R.

[0078] The first shifting mechanism K1 and the second shifting mechanism K2 can selectively engage the first intermediate drive shaft 50 with one of the first intermediate drive gear 41, the second intermediate drive gear 42 and the reverse intermediate drive gear 43, so as to selectively realize the mechanical power of the engine 1 being transmitted to the first intermediate drive shaft 50 in two forward gears and one reverse gear through the linkage of the intermediate shaft gear shifting mechanism 100.

[0079] Furthermore, when the first shift mechanism K1 is in neutral, the second shift mechanism K2 engages the reverse gear driven gear 53 with the gearbox housing, locking the gear ring rotating shaft 40 and the gear ring 4R in place, thereby allowing the engine 1 and the first motor 2 to perform the series linkage power generation function in the planetary gear mechanism 4.

[0080] In some alternative embodiments, see Figures 5 to 8 As shown, this application embodiment provides a power split hybrid power transmission system. The transfer shaft gear shifting mechanism 100 of the power split hybrid power transmission system includes a first transfer gear pair and a reverse transfer gear pair connected between the gear ring transfer shaft 40 and the first intermediate transmission shaft 50 and arranged axially at intervals in sequence.

[0081] The intermediate gear shifting mechanism 100 also includes a first shifting mechanism K1 located between the first intermediate gear pair and the reverse intermediate gear pair for engaging or disengaging the first intermediate gear pair or the reverse intermediate gear pair. The first shifting mechanism K1 achieves the switching between forward and reverse gears by engaging or disengaging the first intermediate gear pair and the reverse intermediate gear pair.

[0082] In some alternative embodiments, see Figures 5 to 7 As shown, the intermediate shaft gear shifting mechanism 100 also includes an intermediate output gear 75 that meshes with the first intermediate gear pair and is loosely fitted on the output shaft 70, and a second shifting mechanism K2 that can be connected to the intermediate output gear 75 and can selectively engage or disengage the intermediate output gear 75 from the output shaft 70 or the gearbox housing; the second shifting mechanism K2 can selectively engage or disengage the intermediate output gear 75 from the output shaft 70 or the gearbox housing to realize the switching between a forward gear of the engine mechanical power splitting and the series linkage power generation.

[0083] In some alternative embodiments, see Figures 5 to 7 As shown, this application embodiment provides a power-split hybrid powertrain system. The first intermediate gear pair of this power-split hybrid powertrain system includes a first intermediate drive gear 41 fixed on the gear ring intermediate shaft 40 and a first driven gear 51 loosely fitted on the first intermediate drive shaft 50. The reverse gear pair includes a reverse drive gear 43 fixed on the gear ring intermediate shaft 40, a reverse driven gear 53 loosely fitted on the first intermediate drive shaft 50, and a reverse idler gear 43R meshing between the reverse drive gear 43 and the reverse driven gear 53. A first shifting mechanism K1 is fixed on the first intermediate drive shaft 50 and located between the first driven gear 51 and the reverse driven gear 53. A second shifting mechanism K2 is loosely fitted on the output shaft 70 and connected to the intermediate output gear 75, and is located between the intermediate output gear 75 and the gearbox housing.

[0084] The first shifting mechanism K1 can selectively engage the first intermediate drive shaft 50 with either the first intermediate driven gear 51 or the reverse intermediate driven gear 53. The second shifting mechanism K2 can selectively engage the intermediate output gear 75 with either the output shaft 70 or the gearbox housing. Thus, the first shifting mechanism K1 can selectively transmit the mechanically diverted power of the engine 1 to the first intermediate drive shaft 50 in a forward gear and a reverse gear, while the second shifting mechanism K2 can selectively transmit the mechanically diverted power of the engine 1 directly to the output shaft 70 in a forward gear, in a forward gear, in the intermediate drive shaft gear shifting mechanism 100.

[0085] Furthermore, when the first shift mechanism K1 is in neutral, after the second shift mechanism K2 is engaged with the gearbox housing, it locks and fixes the rotating shaft 40 and the gear ring 4R in place, thereby allowing the engine 1 and the first motor 2 to perform the series linkage power generation function in the planetary gear mechanism 4.

[0086] In some alternative embodiments, see Figure 1 , Figure 2 , Figure 5and Figure 6 As shown, this application embodiment provides a power-split hybrid power transmission system. The gear shifting mechanism 200 of the power-split hybrid power transmission system includes a first intermediate drive gear 54, a third intermediate drive gear 55, a fifth intermediate drive gear 56 and a sixth intermediate drive gear 57 loosely fitted on a first intermediate drive shaft 50, a first driven output gear 71, a second driven output gear 72, a third driven output gear 73 and a fourth driven output gear 74 fixed on an output shaft 70, and a second intermediate drive gear 61 and a fourth intermediate drive gear 62 loosely fitted on a second intermediate drive shaft 60.

[0087] In this embodiment, the first driven output gear 71 meshes with both the first intermediate driving gear 54 and the second intermediate driving gear 61; the second driven output gear 72 meshes with both the third intermediate driving gear 55 and the fourth intermediate driving gear 62; the fifth intermediate driving gear 56 meshes with the third driven output gear 73; and the sixth intermediate driving gear 57 meshes with the fourth driven output gear 74. A third shifting mechanism K3 is fixedly mounted on the first intermediate drive shaft 50 to engage or disengage the first intermediate driving gear 54 or the third intermediate driving gear 55 from the first intermediate drive shaft 50; a fifth shifting mechanism K5 is fixedly mounted on the first intermediate drive shaft 50 to engage or disengage the fifth intermediate driving gear 56 or the sixth intermediate driving gear 57 from the first intermediate drive shaft 50; and a fourth shifting mechanism K4 is fixedly mounted on the second intermediate drive shaft 60 to engage or disengage the second intermediate driving gear 61 or the fourth intermediate driving gear 62 from the second intermediate drive shaft 60. The driving force of the gear shifting mechanism 200 is ultimately transmitted to the drive axle and wheels via the output shaft 70.

[0088] The gear shifting mechanism 200 in this embodiment forms a four-speed gear coupling assembly for the mechanical power distribution of the engine 1 and the two-speed gear coupling assembly for the second motor 3. It includes a first intermediate driving gear 54, a second intermediate driving gear 61, a third intermediate driving gear 55, a fourth intermediate driving gear 62, a fifth intermediate driving gear 56 and a sixth intermediate driving gear 57, a first driven output gear 71, a second driven output gear 72, a third driven output gear 73, a fourth driven output gear 74, a third shifting mechanism K3, a fourth shifting mechanism K4 and a fifth shifting mechanism K5.

[0089] based on Figure 1 and Figure 2 In the embodiment shown in this application, the central shaft gear shifting mechanism 100 provides two forward gears and one reverse gear transmission assembly. The mechanically split power of the engine 1 is ultimately used to achieve eight forward gears and four reverse gears through the gear shifting mechanism 200, as well as a disengaged series power generation function, while the second motor 3 only provides two independent gear drives. This embodiment is suitable for large tractors with high traction drive requirements.

[0090] based on Figure 5 and Figure 6 In the embodiment shown in this application, the central shaft gear shifting mechanism 100 provides two forward gears and one reverse gear transmission assembly. The mechanical power of the engine 1 is split through the transmission combination of the gear shifting mechanism 200 and the central shaft gear shifting mechanism 100, which can ultimately realize five forward gears and four reverse gears for the mechanical power of the engine 1, as well as the disengagement series power generation function. The second motor 3 still only provides two independent gear drives. This embodiment is suitable for medium and medium-large tractors with large traction drive requirements.

[0091] In some alternative embodiments, see Figure 3 , Figure 4 , Figures 7 to 8 As shown, this application provides a power-split hybrid power transmission system. The gear shifting mechanism 200 of the power-split hybrid power transmission system includes a first intermediate drive gear 54 and a third intermediate drive gear 55 loosely fitted on a first intermediate drive shaft 50, a first driven output gear 71 and a second driven output gear 72 fixed on an output shaft 70, and a second intermediate drive gear 61 and a fourth intermediate drive gear 62 loosely fitted on a second intermediate drive shaft 60.

[0092] Furthermore, the first driven output gear 71 simultaneously meshes with the first intermediate driving gear 54 and the second intermediate driving gear 61, and the second driven output gear 72 simultaneously meshes with the third intermediate driving gear 55 and the fourth intermediate driving gear 62. A third shifting mechanism K3 is fixedly provided on the first intermediate transmission shaft 50 to engage or disengage the first intermediate driving gear 54 or the third intermediate driving gear 55 from the first intermediate transmission shaft 50, and a fourth shifting mechanism K4 is fixedly provided on the second intermediate transmission shaft 60 to engage or disengage the second intermediate driving gear 61 or the fourth intermediate driving gear 62 from the second intermediate transmission shaft 60.

[0093] The gear shifting mechanism 200 in this embodiment forms a two-speed gear coupling assembly for the mechanical power splitting of the engine 1 and the two-speed gear coupling assembly for the second motor 3. It includes a first intermediate driving gear 54, a second intermediate driving gear 61, a third intermediate driving gear 55, a fourth intermediate driving gear 62, a first driven output gear 71, a second driven output gear 72, a third shifting mechanism K3, and a fourth shifting mechanism K4.

[0094] based on Figure 3 and Figure 4The embodiment shown in this application provides a two-speed forward and one-speed reverse transmission assembly via a gear shifting mechanism 100, as well as a disengaged series power generation function. The mechanically diverted power from engine 1 is ultimately used to achieve four forward gears and two reverse gears via the gear shifting mechanism 200, while the second motor 3 provides only two independent gears. This embodiment is suitable for medium and small-to-medium-sized tractors with high traction drive requirements.

[0095] based on Figure 7 In the embodiment shown in this application, the central shaft gear shifting mechanism 100 provides a two-speed forward gear and a one-speed reverse gear transmission assembly. The mechanical power of the engine 1 is split through the gear shifting mechanism 200 and the central shaft gear shifting mechanism 100, which can ultimately realize the three forward gears and two reverse gears of the mechanical power splitting of the engine 1, as well as the disengagement series power generation function. The second motor 3 still only provides two independent gear drives. This embodiment is suitable for small tractors with low traction drive requirements.

[0096] based on Figure 8 The embodiments shown in this application are in Figure 7 Based on the previous embodiment, the second shift mechanism K2 and the intermediate output gear 75 are further simplified and eliminated. Therefore, the intermediate shaft gear shift mechanism 100 provides a forward gear and a reverse gear transmission assembly. The mechanical power of the engine 1 is split through the transmission combination of the gear shift mechanism 200 and the intermediate shaft gear shift mechanism 100, which can ultimately realize the two forward gears and two reverse gears of the mechanical power of the engine 1. The second motor 3 still only provides two independent gear drives. This embodiment is suitable for small and micro tractors with small traction drive requirements.

[0097] Since the mechanical power distribution of engine 1 and the independent transmission path of the second motor 3 are independent of each other, during the gear shifting process of engine 1 through the intermediate shaft gear shifting mechanism 100 and the gear shifting mechanism 200, the second motor 3 can maintain power drive through the intermediate transmission shaft 60 and the gear shifting mechanism 200 in gear linkage, thereby achieving uninterrupted gear shifting of engine 1. Conversely, during the gear shifting control process of second motor 3 disengaging through the second intermediate transmission shaft 60, engine 1 remains in gear drive through the intermediate shaft gear shifting mechanism 100 and the gear shifting mechanism 200, thereby achieving uninterrupted gear shifting control of second motor 3.

[0098] Based on the above description of this application Figures 1 to 8In the power-split hybrid transmission system of this embodiment, the first shift mechanism K1 to the fifth shift mechanism K6 each have three position control states: left closed, neutral, and right closed. Under the combined control of the five shift mechanisms, multi-gear forward and reverse gear drive of the mechanical power split of the engine 1 can be realized respectively, and the second motor 3 can selectively realize two independent forward or reverse gear drive only through the second intermediate drive shaft 60 and the fourth shift mechanism K4.

[0099] According to this application Figures 1 to 8 The power-split hybrid transmission system in this embodiment employs a multi-speed parallel shaft gear mechanism combined with electronically controlled power splitting to achieve the function of a multi-speed electric torque converter. This can replace the inefficient and complex hydraulic splitting structure of traditional mechanical hydraulic continuously variable transmissions (HMCVT). It can realize multiple driving modes for the tractor, including two-speed pure electric drive, multi-speed power-split hybrid, or series hybrid, providing powerful driving capabilities, effectively improving fuel economy, and simultaneously meeting the traction requirements of the tractor from low to high speeds, achieving uninterrupted gear shifting.

[0100] The following describes the matching of this application. Figure 1 The drive mode of the power split hybrid powertrain system in the embodiment.

[0101] When the tractor is in parking charging mode, the on-board power battery is low on power, and the first shift mechanism K1 is in neutral. The second shift mechanism K2 closes to the left, engaging the reverse gear driven gear 53 with the gearbox housing, thereby locking and fixing the gear ring 4R and gear ring rotating shaft 40 of the planetary gear mechanism 4. The engine 1 and the first motor 2 are disengaged and connected in series to generate electricity, charging the on-board power battery.

[0102] When the tractor is in pure electric drive mode, the first shift mechanism K1, the second shift mechanism K2, and / or the third shift mechanism K3 and the fifth shift mechanism K5 are in neutral. The first intermediate drive shaft 50 is disengaged, and the engine 1 and the first motor 2 are disengaged and stopped. The second motor 3 can selectively engage with the gear shift mechanism 200 through the second intermediate drive shaft 60, ultimately achieving forward or reverse drive in two gears. The fourth shift mechanism K4 can selectively engage the second intermediate drive shaft 60 with one of the gears, the second intermediate drive gear 61 and the fourth intermediate drive gear 62, thereby achieving two-gear power transmission.

[0103] When the tractor is in series hybrid mode and the onboard power battery is low on charge, the first shift mechanism K1 is in neutral, and the second shift mechanism K2 closes its connection to the gearbox housing, thereby locking the gear ring shaft 40 and the gear ring 4R in place. The engine 1 and the first motor 2 are disengaged and connected in series to generate electricity, charging the onboard power battery and directly supplying power to the second motor 3. The second motor 3, through the second intermediate drive shaft 60 and the gear shift mechanism 200, can selectively provide two gears for forward or reverse drive.

[0104] When the tractor is in forward gear power split hybrid mode, the second shift mechanism K2 is in neutral. The first shift mechanism K1 can selectively engage the first intermediate drive shaft 50 with either the first intermediate driven gear 51 or the second intermediate driven gear 52. The third shift mechanism K3 and the fifth shift mechanism K5 can selectively engage one of the first intermediate drive gear 54, the third intermediate drive gear 55, the fifth intermediate drive gear 56, and the sixth intermediate drive gear 57 with the first intermediate drive shaft 50. The mechanical power split of the engine 1 can selectively achieve the transmission of eight forward gears. The transmission path is represented as follows:

[0105] Engine 1 → First input shaft 10 → Planetary carrier 4C → Gear ring 4R → Gear ring intermediate shaft 40 → First intermediate drive gear 41 (or second intermediate drive gear 42) → First intermediate driven gear 51 (or second intermediate driven gear 52) → First intermediate transmission shaft 50 → First intermediate drive gear 54 (or third intermediate drive gear 55 or fifth intermediate drive gear 56 or sixth intermediate drive gear 57) → First driven output gear 71 (or second driven output gear 72 or third driven output gear 73 or fourth driven output gear 74) → Output shaft 70.

[0106] Simultaneously, the second motor 3 achieves parallel power assistance or regenerative braking through the two-speed pure electric transmission path of the second intermediate drive shaft 60 described above. During the gear shifting process of engine 1, the gear ring intermediate shaft 40 and the first intermediate drive shaft 50 disengage. The first motor 2, through speed closed-loop control, can quickly achieve synchronous speed control of the first intermediate drive shaft 50 during the gear shifting process. The speed closed-loop control of the first motor 2 can keep the speed difference before and after the gear shift within a set threshold range, thereby achieving smooth and rapid gear shifting, and eliminating the complex and costly clutch and synchronizer shifting mechanism. The second motor 3 provides power compensation in gear, thereby achieving smooth gear shifting control of engine 1 without power interruption.

[0107] When the tractor is in reverse power split hybrid mode, the first shift mechanism K1 is in neutral, the second shift mechanism K2 closes to the right, engaging the first intermediate drive shaft 50 with the reverse intermediate driven gear 53, and the third shift mechanism K3 and the fifth shift mechanism K5 selectively engage one of the first intermediate drive gear 54, the third intermediate drive gear 55, the fifth intermediate drive gear 56, and the sixth intermediate drive gear 57 with the first intermediate drive shaft 50. The mechanical power split of engine 1 can selectively achieve the transmission of four reverse gears, and the transmission path is represented as follows:

[0108] Engine 1 → First input shaft 10 → Planetary carrier 4C → Ring gear 4R → Ring gear intermediate shaft 40 → Reverse gear intermediate drive gear 43 → Reverse gear idler gear 43R → Reverse gear intermediate driven gear 53 → First intermediate transmission shaft 50 → First intermediate drive gear 54 (or third intermediate drive gear 55 or fifth intermediate drive gear 56 or sixth intermediate drive gear 57) → First driven output gear 71 (or second driven output gear 72 or third driven output gear 73 or fourth driven output gear 74) → Output shaft 70.

[0109] Similarly, the second motor 3 achieves reverse gear parallel assist or regenerative braking through the two-speed pure electric transmission path of the second intermediate drive shaft 60 described above. During the gear shifting process of engine 1, the first intermediate drive shaft 50 disengages, and the first motor 2 can achieve synchronous gear shifting control of the first intermediate drive shaft 50 during the gear shifting process. The first motor 2 can control the speed difference before and after gear shifting within a set threshold range through closed-loop speed control, thereby achieving smooth and rapid gear shifting and eliminating the need for a complex and costly clutch and synchronizer shifting mechanism. The second motor 3 provides power compensation in gear, thereby achieving smooth gear shifting control without power interruption during the reverse gearing process of engine 1.

[0110] Regardless of whether it's in forward or reverse power-split mode, the first motor 2 converts a portion of the input power from the engine 1 into electrical energy, and the second motor 3 uses the power provided by the onboard battery and / or the first motor 2 to achieve torque superposition. This realizes the function of an electric torque converter, efficiently improving wheel-side traction capability and fully meeting the high traction drive torque requirements for tractor starting and low-speed forward operation. At the same time, it overcomes the complex transmission mechanical structure of traditional power-shift automatic transmissions, achieving significant cost reduction and efficiency improvement in the transmission system.

[0111] In some alternative embodiments, see Figures 1 to 8As shown in the figure, this application embodiment provides a power split hybrid power transmission system, which further includes multiple speed sensors (not shown in the figure) for monitoring engine speed, first motor speed, second motor speed, first intermediate drive shaft speed and output shaft speed. The multiple speed sensors are all connected to the transmission controller (not shown in the figure), and the first motor 2 and the second motor 3 are both connected to the transmission controller.

[0112] The transmission controller receives signals of engine speed, first motor speed, second motor speed, first intermediate drive shaft speed, and output shaft speed, and controls the speeds of the first motor 2 and second motor 3 according to the current shift signal to keep the shift speed difference within a set threshold range. When the intermediate shaft gear shifting mechanism 100 and gear shifting mechanism 200 need to shift gears, the transmission controller can obtain the engine speed, first motor speed, second motor speed, first intermediate drive shaft speed, and output shaft speed.

[0113] The gearbox controller can achieve closed-loop control of the shift gear speed by controlling the speed changes of the first motor 2 and the second motor 3, so that the speed difference between the driving end and the driven end of the shift gear is controlled within the set speed difference threshold, thereby simplifying the first shift mechanism K1 to the fifth shift mechanism K5. The first shift mechanism K1 to the fifth shift mechanism K5 adopts a more simplified meshing sleeve shift mechanism or a dog tooth shift mechanism to replace the synchronizer shift mechanism, and the shift clutch is also eliminated.

[0114] A second aspect of this application provides a tractor that includes the power-split hybrid drive system described in any of the above embodiments. A portion of the power from the tractor's engine 1 is efficiently converted into electrical energy by a first motor 2, thereby charging and buffering the onboard power battery, or a portion of the electrical energy is efficiently and directly supplied to a second motor 3 for driving.

[0115] Compared to traditional hydraulic continuously variable transmissions (HMCVTs) that convert the input power of engine 1 through hydraulic flow, resulting in the loss of some of the engine 1's input power through hydraulic consumption, this application achieves higher energy conversion efficiency through electronic power flow conversion, which can significantly improve the tractor's fuel economy.

[0116] Meanwhile, by setting up a power splitting mechanical structure with multiple gears, the drive requirements for the second motor 3 can be effectively reduced. In addition, in power splitting mode, even when the tractor is running at a continuously extremely low speed, the mechanical power splitting of engine 1 can be directly output in multiple gears. Due to the assistance of the second motor 3, a high torque traction drive output at low gears can be achieved, which can meet the needs of most crawling drive operations.

[0117] The tractor of this application uses a power-split hybrid transmission system, which can cover more driving conditions and take into account the driving needs of low speed and medium-high speed, thereby reducing the overall energy consumption and emissions. In addition, since the transmission paths of engine 1 and second motor 3 are set independently, power compensation can be achieved for the shifting process of engine 1 and second motor 3, so as to achieve smooth shifting without power interruption. This can improve the driving experience, improve the driving comfort and shifting smoothness of the tractor, and also improve the working efficiency of the tractor.

[0118] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0119] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0120] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A power-split hybrid powertrain system, characterized in that, include: An electronic continuously variable transmission (CVT) includes a planetary gear mechanism (4) consisting of a sun gear (4S), a planet carrier (4C), and a ring gear (4R), and a first input shaft (10) connected to the planet carrier (4C) and axially passing through the planetary gear mechanism (4). One end of the first input shaft (10) is connected to an engine (1), a first motor (2) that is drivenly connected to the sun gear (4S), and a ring gear pivot shaft (40) that is connected to the ring gear (4R) and loosely fitted around the outer periphery of the first input shaft (10). The dual-power coupling mechanism includes a first intermediate drive shaft (50), a second intermediate drive shaft (60), and an output shaft (70) that are parallel to each other and spaced apart, and a transfer shaft gear shifting mechanism (100) connected between the first intermediate drive shaft (50) and the gear ring transfer shaft (40). A second motor (3) is connected to the second intermediate drive shaft (60) and a gear shifting mechanism (200) is connected between the first intermediate drive shaft (50), the output shaft (70) and the second intermediate drive shaft (60).

2. The power-split hybrid powertrain system as described in claim 1, characterized in that: The first motor (2) is connected to the sun gear (4S) via the second input shaft (20). The second input shaft (20) is loosely fitted around the outer circumference of the first input shaft (10). The first input shaft (10) also serves as the PTO transmission output shaft for power output and passes through both sides of the planetary gear mechanism (4). The first motor (2) is coaxially connected to the second input shaft (20), or the first motor (2) is biasedly connected to the second input shaft (20) through a first bias gear coupling mechanism. The first bias gear coupling mechanism includes a first active bias gear (21) connected to the first motor (2). The first driven bias gear (22) is connected to the second input shaft (20), and the diameter of the first driving bias gear (21) is smaller than the diameter of the first driven bias gear (22) and they mesh with each other.

3. The power-split hybrid powertrain system as described in claim 1, characterized in that: The second motor (3) is biasedly connected to the second intermediate transmission shaft (60) through a second bias gear coupling mechanism. The second bias gear coupling mechanism includes a third input shaft (30) connected to the second motor (3), a second active bias gear (31) and a second driven bias gear (32) connected between the third input shaft (30) and the second intermediate transmission shaft (60) and meshing with each other. The second active bias gear (31) is fixedly sleeved on the third input shaft (30), and the second driven bias gear (32) is fixedly sleeved on the second intermediate transmission shaft (60).

4. The power-split hybrid powertrain system as described in claim 1, characterized in that: The central gear shifting mechanism (100) includes a first central gear pair, a second central gear pair and a reverse central gear pair connected between the central gear ring central shaft (40) and the first intermediate transmission shaft (50) and arranged axially at intervals in sequence; A first shifting mechanism (K1) located between the first intermediate gear pair and the second intermediate gear pair for engaging or disengaging the first intermediate drive shaft (50) with the first intermediate gear pair or the second intermediate gear pair, and a second shifting mechanism (K2) for engaging or disengaging the reverse gear pair with the first intermediate drive shaft (50) or the gearbox housing.

5. The power-split hybrid powertrain system as described in claim 4, characterized in that: The first intermediate gear pair includes a first intermediate driving gear (41) fixedly sleeved on the intermediate shaft (40) of the gear ring, and a first intermediate driven gear (51) loosely sleeved on the first intermediate transmission shaft (50). The second intermediate gear pair includes a second intermediate driving gear (42) fixedly sleeved on the intermediate shaft (40) of the gear ring, and a second intermediate driven gear (52) loosely sleeved on the first intermediate transmission shaft (50). The reverse gear pair includes a reverse gear drive gear (43) fixedly sleeved on the gear ring drive shaft (40), a reverse gear driven gear (53) loosely sleeved on the first intermediate transmission shaft (50), and a reverse idler gear (43R) meshing between the reverse gear drive gear (43) and the reverse gear driven gear (53). The first shift mechanism (K1) is fixed on the first intermediate drive shaft (50) and located between the first intermediate driven gear (51) and the second intermediate driven gear (52), and can selectively engage or disengage the first intermediate drive shaft (50) with the first intermediate driven gear (51) or the second intermediate driven gear (52); the second shift mechanism (K2) is connected to the reverse intermediate driven gear (53) and located between the reverse intermediate driven gear (53) and the gearbox housing, and can selectively engage or disengage the reverse intermediate driven gear (53) with the first intermediate drive shaft (50) or the gearbox housing.

6. The power-split hybrid powertrain system as described in claim 1, characterized in that: The intermediate shaft gear shifting mechanism (100) includes a first intermediate gear pair and a reverse gear pair connected between the gear ring intermediate shaft (40) and the first intermediate transmission shaft (50) and arranged axially spaced in sequence, and a first shifting mechanism (K1) located between the first intermediate gear pair and the reverse gear pair for engaging or disengaging the first intermediate gear pair or the reverse gear pair. The first intermediate gear pair includes a first intermediate driving gear (41) fixedly sleeved on the intermediate shaft (40) of the gear ring, and a first intermediate driven gear (51) loosely sleeved on the first intermediate transmission shaft (50). The reverse gear pair includes a reverse gear drive gear (43) fixedly sleeved on the gear ring drive shaft (40), a reverse gear driven gear (53) loosely sleeved on the first intermediate transmission shaft (50), and a reverse idler gear (43R) meshing between the reverse gear drive gear (43) and the reverse gear driven gear (53). The first shifting mechanism (K1) is fixed on the first intermediate drive shaft (50) and located between the first intermediate driven gear (51) and the reverse intermediate driven gear (53), and can selectively engage or disengage the first intermediate drive shaft (50) with the first intermediate driven gear (51) or the reverse intermediate driven gear (53).

7. A power-split hybrid powertrain system as described in claim 6, characterized in that: The intermediate shaft gear shifting mechanism (100) further includes an intermediate output gear (75) that meshes with the first intermediate gear pair and is loosely fitted on the output shaft (70), and a second shifting mechanism (K2) that can selectively engage or disengage the intermediate output gear (75) from the output shaft (70) or the gearbox housing. The intermediate output gear (75) meshes with the first intermediate driven gear (51), and the second shifting mechanism (K2) is connected to the sleeve shaft of the intermediate output gear (75).

8. The power-split hybrid powertrain system as described in claim 1, characterized in that: The gear shifting mechanism (200) includes a first intermediate drive gear (54) and a third intermediate drive gear (55) loosely fitted on the first intermediate drive shaft (50), a first driven output gear (71) and a second driven output gear (72) fixed on the output shaft (70), and a second intermediate drive gear (61) and a fourth intermediate drive gear (62) loosely fitted on the second intermediate drive shaft (60). The first driven output gear (71) meshes with the first intermediate driving gear (54) and the second intermediate driving gear (61) simultaneously. The second driven output gear (72) meshes with the third intermediate driving gear (55) and the fourth intermediate driving gear (62) simultaneously. A third shifting mechanism (K3) is fixedly provided on the first intermediate transmission shaft (50) to drive the first intermediate driving gear (54) or the third intermediate driving gear (55) to engage or disengage from the first intermediate transmission shaft (50). A fourth shifting mechanism (K4) is fixedly provided on the second intermediate transmission shaft (60) to drive the second intermediate driving gear (61) or the fourth intermediate driving gear (62) to engage or disengage from the second intermediate transmission shaft (60).

9. A power-split hybrid powertrain system as described in claim 8, characterized in that: The gear shifting mechanism (200) further includes a fifth intermediate drive gear (56) and a sixth intermediate drive gear (57) loosely fitted on the first intermediate drive shaft (50), and a third driven output gear (73) and a fourth driven output gear (74) fixed on the output shaft (70). The fifth intermediate driving gear (56) meshes with the third driven output gear (73), the sixth intermediate driving gear (57) meshes with the fourth driven output gear (74), and a fifth shifting mechanism (K5) is fixedly provided on the first intermediate transmission shaft (50) to engage or disengage the fifth intermediate driving gear (56) or the sixth intermediate driving gear (57) from the first intermediate transmission shaft (50).

10. A tractor, characterized in that, The tractor includes the power-split hybrid powertrain system as described in any one of claims 1 to 9.

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