Electric vehicle independent power split transmission driveline and method thereof

Abstract

The invention relates to an electric vehicle (EV) independent power split transmission driveline (100) comprising: at least two prime movers comprising a first electric machine (M1) for driving a plurality of wheels and a second electric machine (M2) for driving a power take-off shaft (Power Take-Off, PTO); a transmission unit comprising a bipolar reduction gearbox, which uses a plurality of traction gear pairs (GP1, GP2, GP3, GP4, GP5, GP6, GP7, GP7) to split power between the front axle (101) and the rear axle (102) and a plurality of PTO gear pairs (GP8, GP9, GP10, GP11) to split power between the middle PTO (103) and the rear PTO (104); a flexible coupling (C1) connecting the output shafts of the first motor (M1) and the second motor (M2) to the transmission unit; and the meshing sleeve (S1) can be assembled between the traction gear pair (GP1) and the traction gear pair (GP2). The invention advantageously improves the versatility and efficiency of the electric vehicle.

Description

TECHNICAL FIELD

[0001] The present invention relates to a powertrain architecture. More specifically, the present invention relates to an electric vehicle (EV) independent power split transmission powertrain, and in particular to an electric tractor that provides independent road speed and unlimited power take-off (PTO) speed. By overcoming the problem of speed interdependence, the present invention advantageously improves the versatility and efficiency of electric vehicles and provides a more robust and flexible power distribution system. BACKGROUND

[0002] An electric tractor combines the principles of electric vehicle (EV) architecture with the specific needs of agricultural work, representing a major advance in agricultural technology. The architecture of an electric tractor aims to optimize field efficiency and sustainability. Unlike traditional tractors that rely on internal combustion engines (ICE), the powertrain of an electric tractor is simpler and has fewer moving parts, reducing maintenance needs and enabling quieter operation. With no exhaust system, an electric tractor achieves zero emissions, making it an environmentally friendly choice for farmers.

[0003] For example, the powertrain of an electric tractor typically consists of a high-voltage battery pack, an inverter, and a motor controller. The battery pack, usually composed of lithium-ion batteries, stores electrical energy and powers the vehicle. The inverter, connected to the motor controller, converts the direct current from the battery pack into alternating current. The motor controller manages the electrical energy that flows to the electric motor, which propels the tractor forward. In addition to the powertrain, the architecture of an electric vehicle includes an advanced electronic control unit (ECU) that manages various vehicle systems such as traction control, braking, and infotainment.

[0004] Some prior art is as follows:

[0005] US7421917 B2 discloses a tractor equipped with a PTO device, comprising a plurality of wheels; a vehicle body supported by the plurality of wheels; an engine supported on the vehicle body; a rear PTO shaft provided at a rear portion of the vehicle body for transmitting power from the engine; a middle PTO shaft provided below the vehicle body for transmitting power from the engine; a PTO mode selection device having a first position for transmitting power only to the rear PTO shaft, a second position for transmitting power to both the rear PTO shaft and the middle PTO shaft, and a third position for transmitting power only to the middle PTO shaft; a PTO clutch provided on a transmission line upstream of the PTO mode selection device and switchable between an engaged position and a disengaged position; a restriction mechanism for preventing a change operation of the PTO mode selection device when the PTO clutch is in the engaged position, and allowing the change operation of the PTO mode selection device when the PTO clutch is in the disengaged position.

[0006] US11981213 B2 discloses an electric drive train and method of operating the drive train, first and second motor generators are rotatably coupled with a planetary assembly, the planetary assembly is rotatably coupled with a drive axle through an output gear. The system further includes a controller, in a first operating condition, the controller can operate each of the first and second motor generators in a motor mode or a generator mode and cause the output gear to remain at zero rotational speed.

[0007] US20230099321 A1 discloses an electric drive train system and method of operating an electric drive train system, including an electric drive unit with a planetary gear set, the planetary gear set includes a first gear set component, the first gear set component is rotatably coupled with a first electric motor and a second electric motor. In addition, the electric drive unit further includes an output shaft rotatably coupled with a second gear set component in the planetary gear set, a first friction clutch selectively brakeable to a third gear set component in the planetary gear set, and a second friction clutch selectively couplable the first gear set component with the output shaft.

[0008] The electric vehicle conventional electric drive train discussed in the prior art includes an electric motor, which is usually connected to the wheels through a single drive train, and the power output is split between traction and PTO functions. This means that the speed of the PTO must be limited by the road speed, because the electric motor can only produce a certain amount of torque. This limitation restricts the ability to control the PTO speed independently of the road speed, which can pose a challenge in applications such as tractors and field equipment.

[0009] Therefore, there is a need for an improved electric vehicle independent power split transmission drive train that provides 100% power split for each traction and PTO drive device, improves PTO speed, improves traction performance, and is suitable for various tractor and field applications. SUMMARY

[0010] TECHNICAL PROBLEM

[0011] The main purpose of the present application is to provide an electric vehicle (EV) independent power split transmission drive train to improve PTO speed, thereby making it suitable for applications that require high-speed PTO operation.

[0012] Another purpose of the present application is to provide an independent power split transmission drive train that provides dedicated power to the wheels, improves traction and stability on uneven or slippery road surfaces.

[0013] Another purpose of the present application is to provide an independent power split transmission drive train that optimizes power distribution for each drive device, reduces energy waste, and improves overall efficiency.

[0014] Another object of the present invention is to provide an independent power split transmission drive train to distribute power between front and rear wheels in a four-wheel drive system, or between left and right wheels in a two-wheel drive system.

[0015] Technical Solution

[0016] The main aspect of the present invention is to provide an electric vehicle (EV) independent power split transmission drive train 100 comprising: at least two prime movers including a first electric motor M1 for driving a plurality of wheels and a second electric motor M2 for driving power take-off (PTO); a transmission unit comprising a dual reduction gear box for power split between front and rear axles using a plurality of traction gear pairs GP1, GP2, GP3, GP4, GP5, GP6, GP7 and between mid-mounted PTO and rear-mounted PTO using a plurality of PTO gear pairs GP8, GP9, GP10, GP11; a flexible coupling C1 connecting the output shafts of the first electric motor M1 and the second electric motor M2 to the transmission unit; an engagement sleeve S1 fittable between the traction gear pair GP1 and the traction gear pair GP2. The dual reduction gear box can be in neutral, when the vehicle is started, the traction gear pair GP1, the traction gear pair GP2 are free to rotate without engaging with the output shafts.

[0017] The independent power split transmission drive train 100 operates in the following modes comprising:

[0018] (i) two-wheel drive (2WD) mode, the first electric motor M1 drives the rear axle 102, when the vehicle accelerator pedal is depressed, the output shaft of the first electric motor M1 rotates, power from the first electric motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, the engagement sleeve S1 engages with the traction gear pair GP1 or the traction gear pair GP2 according to the shift direction selected by the user using the shift lever, when the engagement sleeve S1 engages with the traction gear pair GP1 or the traction gear pair GP2, power is transmitted from the traction gear pair GP1 or the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7 to provide the rear axle 102 with the required power to drive the rear wheels,

[0019] (ii) Four-wheel drive (4WD) mode, the first motor M1 drives the front axle 101 and the rear axle 102 simultaneously, when the vehicle accelerator pedal is pressed, the output shaft of the first motor M1 rotates, the power from the first motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, according to the shift direction selected by the user using the shift lever, the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, when the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, the power is transmitted from the traction gear pair GP1 to the traction gear pair GP3 to the traction gear pair GP7, or from the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the power required for the driving rear wheels of the rear axle 102, at the same time, when the engagement sleeve S2 is engaged, the power is transmitted from the traction gear pair GP3 to the traction gear pair GP4 to the traction gear pair GP5 to the traction gear pair GP6, to provide the power required for the driving front wheels of the front axle 101,

[0020] (iii) PTO motor mode: the second motor M2 drives the PTO, when the electrical control lever is actuated, the output shaft of the second motor M2 rotates, the power is transmitted from the second motor M2 to the PTO gear pair GP8 and the PTO gear pair GP11, when the engagement sleeve S3 is engaged with the PTO gear pair GP8, the power is transmitted from the PTO gear pair GP8 to the PTO gear pair GP9, and then to the PTO gear pair GP10, to provide power for the middle PTO, when the engagement sleeve S4 is engaged with the PTO gear pair GP11, the PTO gear pair GP11 directly provides power for the rear PTO, when the engagement sleeve S3 and the engagement sleeve S4 are engaged with the PTO gear pair GP8 and the PTO gear pair GP11, the middle PTO and the rear PTO both obtain power.

[0021] Another aspect of the present application is to provide a working method of an electric vehicle (EV) independent power split transmission drive train (100), the method comprising the following steps:

[0022] a. In two-wheel drive (2WD) mode: the first motor M1 drives the rear axle 102, when the vehicle accelerator pedal is pressed, the output shaft of the first motor M1 rotates, the power from the first motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, according to the shift direction selected by the user using the shift lever, the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, when the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, the power is transmitted from the traction gear pair GP1 or the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the power required for the driving rear wheels of the rear axle 102,

[0023] b. In four-wheel drive (4WD) mode: by driving the front axle 101 and the rear axle 102 simultaneously through the first motor M1, when the vehicle accelerator pedal is stepped on, the output shaft of the first motor M1 rotates, power from the first motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, according to the shift direction when the user selects high speed using the shift lever, the mesh sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, when the mesh sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, power is transmitted from the traction gear pair GP1 to the traction gear pair GP3 to the traction gear pair GP7, or from the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the rear axle 102 with the power required to drive the rear wheels, at the same time, when the mesh sleeve S2 is engaged, power is transmitted from the traction gear pair GP3 to the traction gear pair GP4 to the traction gear pair GP5 to the traction gear pair GP6, to provide the front axle 101 with the power required to drive the front wheels,

[0024] c. (iii) In PTO motor mode: by driving the PTO through the second motor M2, when the electrical control lever is actuated, the output shaft of the second motor M2 rotates, power from the second motor M2 is transmitted to the PTO gear pair GP8 and the PTO gear pair GP11, when the mesh sleeve S3 is engaged with the PTO gear pair GP8, power is transmitted from the PTO gear pair GP8 to the PTO gear pair GP9, and then to the PTO gear pair GP10, to provide power to the mid-mounted PTO, when the mesh sleeve S4 is engaged with the PTO gear pair GP11, power is directly transmitted through the PTO gear pair GP11 to provide power to the rear-mounted PTO, when the mesh sleeve S3 and the mesh sleeve S4 are engaged with the PTO gear pair GP8 and the PTO gear pair GP11, both the mid-mounted PTO and the rear-mounted PTO are powered.

[0025] Effects of the invention

[0026] The present invention relates to an independent power split transmission drive train, which can provide additional power transmission to the front axle, which is crucial for heavy load tasks and improving vehicle stability and traction.

[0027] The present invention relates to an independent power split transmission drive train, which can split power according to demand, which means that the vehicle can operate more efficiently, reducing energy waste and improving overall performance.

[0028] The present invention relates to an independent power split transmission drive train, which can operate the PTO at the required speed without being affected by the speed of the vehicle on the road, which is crucial for tasks that require consistent PTO performance.

[0029] The present invention relates to an independent power split transmission drive train which ensures the best performance of the vehicle in terms of both driving and auxiliary functions, which is a major improvement compared to the conventional electric vehicle architecture, whose top speed is usually limited by the maximum angular speed of the electric motor. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of an electric vehicle (EV) independent power split transmission drive train in two-wheel drive configuration mode, according to the present invention.

[0031] Figure 2 is a schematic diagram of an electric vehicle (EV) independent power split transmission drive train in four-wheel drive configuration mode, according to the present invention.

[0032] Figure 3 is a schematic diagram of an electric vehicle (EV) independent power split transmission drive train in PTO configuration mode.

[0033] Figure 4 is a view of an electric vehicle (EV) independent power split transmission drive train, according to the present invention.

[0034] Figure 5 is a view of an electric vehicle (EV) independent power split transmission drive train, according to the present invention.

[0035] EXPLANATION OF REFERENCE NUMERALS

[0036] 100: Independent power split transmission drive train

[0037] 101: Front axle

[0038] 102: Rear axle

[0039] 103: Mid-mounted PTO

[0040] 104: Rear-mounted PTO

[0041] C1: Flexible coupling

[0042] GP1, GP2, GP3, GP4, GP5, GP6, GP7: Traction gear pair

[0043] GP8, GP9, GP10, GP11: PTO gear pair

[0044] M1: First electric motor

[0045] M2: Second electric motor

[0046] S1, S2, S3, S4: Engagement sleeve DETAILED DESCRIPTION

[0047] This invention is specifically embodied in "an independent power split transmission system 100 for electric vehicles (EVs) and its method," and concisely satisfies the aforementioned needs in the art. This invention has objectives arising from the aforementioned needs, which have been listed above.

[0048] The following description relates to an independent power split transmission system 100 for an electric vehicle (EV) and its method. While the objectives of the invention are set forth, it will be apparent to those skilled in the art that the set forth objectives are not exhaustive descriptions of the entire invention, but are merely illustrative. Furthermore, although no structural alternatives and / or functional equivalents are explicitly mentioned in this disclosure or elsewhere, such structural alternatives and / or functional equivalents are included within the scope and rights of the invention. Therefore, the invention also includes within its scope and rights any modifications / alterations applied to the structural / functional alternatives. The invention may be embodied in other specific forms without departing from its essential attributes.

[0049] Furthermore, the terminology and phrases used in this invention are not intended to be limiting, but rather to provide an understandable description. The use of the word "comprise" throughout this specification, as well as variations such as "comprises" and "comprising," may imply the inclusion of elements not specifically described.

[0050] Conventional electric drive systems discussed in the prior art include an electric motor, which is typically connected to the wheels via a single drivetrain, with power output split between traction and PTO (Power To-Drive) functions. This means that the PTO speed must be limited by the road speed because the electric motor can only produce a certain amount of torque. This limitation restricts the ability to control the PTO speed independently of the road speed, which can pose a challenge in applications such as tractors and field equipment. Conventional drive systems may struggle to meet the demands of maintaining a constant PTO speed while road speeds vary, without an additional system to decouple the speed. The single drivetrain and fixed torque output limit the flexibility of electric drive systems in adapting to different operating conditions or applications.

[0051] However, in this invention, the electric drive system can more precisely control power distribution, improve vehicle performance and efficiency, provide a balance between torque and speed, achieve better traction control and adaptability to different driving conditions, and ensure that power is efficiently transmitted to the most needed location without affecting vehicle maneuverability.

[0052] Please see Figure 1In an embodiment of the present invention, an independent power split transmission system 100 for an electric vehicle (EV) is provided, comprising: at least two prime movers, including a first motor M1 for driving multiple wheels and a second motor M2 for driving a power output shaft (PTO); a transmission unit, including a double-stage reduction gearbox, using multiple traction gear pairs GP1, GP2, GP3, GP4, GP5, GP6, GP7 to split power between the front and rear axles and using multiple PTO gear pairs GP8, GP9, GP10, GP11 between the mid-mounted PTO and the rear-mounted PTO; a flexible coupling C1 connecting the output shafts of the first motor M1 and the second motor M2 to the transmission unit; and a meshing sleeve S1, which can be fitted between the traction gear pairs GP1 and GP2. The double-stage reduction gearbox can be in neutral, and when the vehicle is started, the traction gear pairs GP1 and GP2 rotate freely without engaging with the output shaft.

[0053] The independent power split transmission system 100, which operates in the following mode, includes:

[0054] (i) In two-wheel drive (2WD) mode, the first motor M1 drives the rear axle 102. When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, and the power from the first motor M1 is transmitted to the traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever, the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2. When the engagement sleeve S1 is engaged with either the traction gear pair GP1 or GP2, power is transmitted from either the traction gear pair GP1 or GP2 to the traction gear pairs GP3 to GP7, providing the power required to drive the rear wheels of the rear axle 102.

[0055] (ii) In four-wheel drive (4WD) mode, the first motor M1 simultaneously drives both the front and rear axles (101, 102). When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, and power from the first motor M1 is transmitted to traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever at high speed, the engagement sleeve S1 engages with either traction gear pair GP1 or GP2. When the engagement sleeve S1 engages with either traction gear pair GP1 or GP2, power is transmitted from traction gear pair GP1 to traction gear pairs GP3 to GP7, or from traction gear pair GP2 to traction gear pairs GP3 to GP7, providing the power required to drive the rear wheels of the rear axle 102. Simultaneously, when the engagement sleeve S2 engages, power is transmitted from traction gear pair GP3 to traction gear pairs GP4 to GP5 to GP6, providing the power required to drive the front wheels of the front axle 101.

[0056] (iii) PTO motor mode: The second motor M2 drives the PTO. When the electrical control lever is activated, the output shaft of the second motor M2 rotates, and the power is transmitted from the second motor M2 to the PTO gear pair GP8 and PTO gear pair GP11. When the meshing sleeve S3 meshes with the PTO gear pair GP8, the power is transmitted from the PTO gear pair GP8 to the PTO gear pair GP9, and then to the PTO gear pair GP10, providing power to the mid-mounted PTO. When the meshing sleeve S4 meshes with the PTO gear pair GP11, the PTO gear pair GP11 directly provides power to the rear-mounted PTO. When the meshing sleeves S3 and S4 mesh with the PTO gear pairs GP8 and GP11, both the mid-mounted PTO and the rear-mounted PTO receive power.

[0057] In an embodiment of the present invention, the first motor M1 is a traction motor.

[0058] In an embodiment of the present invention, the second motor M2 is a PTO motor.

[0059] In one embodiment of the invention, the centrally located power take-off shaft (PTO) 103 is located in the middle of the vehicle and is used to drive the centrally suspended gardening implement.

[0060] In one embodiment of the present invention, the rear power take-off shaft (PTO) 104 is located at the rear of the vehicle and is used to drive rear-mounted agricultural implements.

[0061] In one embodiment of the present invention, the intermediate-suspension implement includes an intermediate-suspension lawnmower, a hydraulic motor, a gear motor, etc.

[0062] In one embodiment of the present invention, the rear-mounted implements include lawn mowers, rotary tillers, sprayers, etc.

[0063] In one embodiment of the present invention, the traction gear pair GP3 is a small gear with a constant seeding amount.

[0064] Another embodiment of the present invention provides a method for operating an independent power split transmission system 100 for an electric vehicle (EV), the method comprising the following steps:

[0065] a. In two-wheel drive (2WD) mode: The rear axle 102 is driven by the first motor M1. When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, transmitting power from the first motor M1 to the traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever, the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2. When the engagement sleeve S1 is engaged with either the traction gear pair GP1 or GP2, power is transmitted from either the traction gear pair GP1 or GP2 to the traction gear pairs GP3 through GP7, providing the rear axle 102 with the power required to drive the rear wheels.

[0066] b. In four-wheel drive (4WD) mode: The first motor M1 simultaneously drives the front axle 101 and the rear axle 102. When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, transmitting power from the first motor M1 to the traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever at high speed, the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2. When the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2, power is transmitted from traction gear pair GP1 to traction gear pairs GP3 to GP7, or from traction gear pair GP2 to traction gear pairs GP3 to GP7, providing the power required to drive the rear wheels of the rear axle 102. Simultaneously, when the engagement sleeve S2 engages, power is transmitted from traction gear pair GP3 to traction gear pairs GP4 to GP5 to GP6, providing the power required to drive the front wheels of the front axle 101.

[0067] c.(iii) In PTO motor mode: The PTO is driven by the second motor M2. When the electrical control lever is activated, the output shaft of the second motor M2 rotates, transmitting power from the second motor M2 to the PTO gear pair GP8 and PTO gear pair GP11. When the meshing sleeve S3 meshes with the PTO gear pair GP8, the power is transmitted from the PTO gear pair GP8 to the PTO gear pair GP9, and then to the PTO gear pair GP10, providing power to the mid-mounted PTO. When the meshing sleeve S4 meshes with the PTO gear pair GP11, the power is directly provided to the rear-mounted PTO through the PTO gear pair GP11. When the meshing sleeves S3 and S4 mesh with the PTO gear pairs GP8 and PTO gear pair GP11, both the mid-mounted PTO and the rear-mounted PTO receive power.

[0068] Work Example

[0069] An exemplary embodiment discloses an independent power split transmission system for an electric vehicle (EV), comprising at least two prime movers, including a first motor M1 for driving multiple wheels and a second motor M2 for driving a power output shaft (PTO); a transmission unit, including a two-stage reduction gearbox, using multiple traction gear pairs GP1, GP2, GP3, GP4, GP5, GP6, GP7 to split power between the front axle 101 and the rear axle 102, and using multiple PTO gear pairs GP8, GP9, GP10, GP11 to split power between the central power output shaft (PTO) 103 and the rear power output shaft (PTO) 104; a flexible coupling C1 connecting the output shafts of the first motor M1 and the second motor M2 to the transmission unit; and a meshing sleeve S1 that can be fitted between the traction gear pairs GP1 and GP2. The two-stage reduction gearbox can be in neutral, and when the vehicle starts, the traction gear pairs GP1 and GP2 rotate freely without engaging with the output shaft.

[0070] The independent power split transmission system operating in the following mode includes:

[0071] (i) In two-wheel drive (2WD) mode, the first motor M1 drives the rear axle 102. When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, and the power from the first motor M1 is transmitted to the traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever, the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2. When the engagement sleeve S1 is engaged with either the traction gear pair GP1 or GP2, power is transmitted from either the traction gear pair GP1 or GP2 to the traction gear pairs GP3 to GP7, providing the power required to drive the rear wheels of the rear axle 102.

[0072] (ii) In four-wheel drive (4WD) mode, the first motor M1 simultaneously drives the front axle 101 and the rear axle 102. When the accelerator pedal is depressed, the output shaft of the first motor M1 rotates, and power from the first motor M1 is transmitted to the traction gear pairs GP1 and GP2. Depending on the shift direction selected by the user using the shift lever at high speed, the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2. When the engagement sleeve S1 engages with either the traction gear pair GP1 or GP2, power is transmitted from the traction gear pair GP1 to the traction gear pairs GP3 to GP7, or from the traction gear pair GP2 to the traction gear pairs GP3 to GP7, providing the power required to drive the rear wheels of the rear axle 102. Simultaneously, when the engagement sleeve S2 engages, power is transmitted from the traction gear pair GP3 to the traction gear pairs GP4 to GP5 to GP6, providing the power required to drive the front wheels of the front axle 101.

[0073] (iii) PTO motor mode: The second motor M2 drives the PTO. When the electrical control lever is activated, the output shaft of the second motor M2 rotates, and the power is transmitted from the second motor M2 to the PTO gear pair GP8 and PTO gear pair GP11. When the meshing sleeve S3 meshes with the PTO gear pair GP8, the power is transmitted from the PTO gear pair GP8 to the PTO gear pair GP9, and then to the PTO gear pair GP10, providing power to the mid-mounted PTO. When the meshing sleeve S4 meshes with the PTO gear pair GP11, the PTO gear pair GP11 directly provides power to the rear-mounted PTO. When the meshing sleeves S3 and S4 mesh with the PTO gear pairs GP8 and GP11, both the mid-mounted PTO and the rear-mounted PTO receive power.

[0074] It will be apparent to those skilled in the art that the above description is for illustrative purposes only and should not be construed as restrictive. Various modifications, additions, alterations, and improvements can be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An electric vehicle independent power split transmission drive train (100), comprising: a. at least two prime movers including a first electric motor M1 for driving a plurality of wheels and a second electric motor M2 for driving a power take-off shaft; b. a transmission unit including a dual reduction gear box using a plurality of traction gear pairs (GP1, GP2, GP3, GP4, GP5, GP6, GP7, GP7) for power split between a front axle (101) and a rear axle (102) and a plurality of power take-off shaft gear pairs (GP8, GP9, GP10, GP11) for power split between a mid-mounted power take-off shaft (103) and a rear-mounted power take-off shaft (104); c. a flexible coupling CI connecting the output shafts of the first electric motor M1 and the second electric motor M2 to the transmission unit; and d. an engagement sleeve SI that can be fitted between the traction gear pair GP1 and the traction gear pair GP2; wherein the dual reduction gear box can be in neutral, when the vehicle is started, the traction gear pair GP1, the traction gear pair GP2 are free to rotate without engaging with the output shafts, wherein the independent power split transmission drive train operating in modes includes: (i) a two-wheel drive (2WD) mode, the first electric motor M1 drives the rear axle (102), when the vehicle accelerator pedal is depressed, the output shaft of the first electric motor M1 rotates, power from the first electric motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, the engagement sleeve SI engages with the traction gear pair GP1 or the traction gear pair GP2 according to the gear shift direction selected by the user using the gear shift lever, when the engagement sleeve SI engages with the traction gear pair GP1 or the traction gear pair GP2, power is transmitted from the traction gear pair GP1 or the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7 to provide the rear axle (102) with the required power to drive the rear wheels; (ii) a four-wheel drive (4WD) mode, the first electric motor M1 drives both the front axle (101) and the rear axle (102), when the vehicle accelerator pedal is depressed, the output shaft of the first electric motor M1 rotates, power from the first electric motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, the engagement sleeve SI engages with the traction gear pair GP1 or the traction gear pair GP2 according to the gear shift direction selected by the user using the gear shift lever when in high speed, when the engagement sleeve SI engages with the traction gear pair GP1 or the traction gear pair GP2, power is transmitted from the traction gear pair GP1 to the traction gear pair GP3 to the traction gear pair GP7, or from the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the rear axle (102) with the required power to drive the rear wheels, while, when the engagement sleeve S2 engages, power is transmitted from the traction gear pair GP3 to the traction gear pair GP4 to the traction gear pair GP5 to the traction gear pair GP6 to provide the front axle (101) with the required power to drive the front wheels; and (iii) Power take-off shaft motor mode: the second motor M2 drives the power take-off shaft, when the electrical control lever is actuated, the output shaft of the second motor M2 rotates, power is transmitted from the second motor M2 to the power take-off shaft gear pair GP8 and the power take-off shaft gear pair GP11, when the engagement sleeve S3 is engaged with the power take-off shaft gear pair GP8, power is transmitted from the power take-off shaft gear pair GP8 to the power take-off shaft gear pair GP9 and then to the power take-off shaft gear pair GP10, to provide power for the middle power take-off shaft, when the engagement sleeve S4 is engaged with the power take-off shaft gear pair GP11, the power take-off shaft gear pair GP11 directly provides power for the rear power take-off shaft, when the engagement sleeve S3 and the engagement sleeve S4 are engaged with the power take-off shaft gear pair GP8 and the power take-off shaft gear pair GP11, both the middle power take-off shaft and the rear power take-off shaft obtain power.

2. The independent power split transaxle (100) of claim 1, wherein, The first motor M1 is a traction motor.

3. The independent power split transaxle (100) of claim 1, wherein, The second motor M2 is a power take-off shaft motor directly connected to the traction gear pair GP7 and the power take-off shaft gear pair GP8.

4. The independent power split transaxle (100) of claim 1, wherein, The middle power take-off shaft (103) is located in the middle of the vehicle and is used to drive the intermediate suspension type garden machine.

5. The independent power split transaxle (100) of claim 1, wherein, The traction gear pair GP3 is a constant seeding gear.

6. The independent power split transaxle (100) of claim 1, wherein, The rear power take-off shaft (104) is located at the rear of the vehicle and is used to drive the rear suspension type agricultural machine.

7. The independent power split transaxle (100) of claim 1, wherein, The intermediate suspension type machine includes an intermediate suspension type mower, a hydraulic motor, and a gear motor.

8. The independent power split transaxle (100) of claim 1, wherein, The rear suspension type machine includes a lawn mower, a rotary tiller, and a sprayer.

9. The working method of the independent power split transmission drive train (100) according to claim 1, the method comprising the following steps: a. In two-wheel drive (2WD) mode: drive the rear axle (102) by the first motor M1, when the vehicle accelerator pedal is depressed, the output shaft of the first motor M1 rotates, power from the first motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, according to the gear shifting direction selected by the user using the gear shifting lever, the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, when the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, power is transmitted from the traction gear pair GP1 or the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the power required for driving the rear wheels of the rear axle (102), b. In four-wheel drive (4WD) mode: by driving the front axle and the rear axle (101, 102) simultaneously through the first motor M1, when the vehicle accelerator pedal is stepped on, the output shaft of the first motor M1 rotates, the power from the first motor M1 is transmitted to the traction gear pair GP1 and the traction gear pair GP2, according to the shift direction when the user selects high speed using the shift lever, the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, when the engagement sleeve S1 is engaged with the traction gear pair GP1 or the traction gear pair GP2, the power is transmitted from the traction gear pair GP1 to the traction gear pair GP3 to the traction gear pair GP7, or from the traction gear pair GP2 to the traction gear pair GP3 to the traction gear pair GP7, to provide the power required for driving the rear wheels of the rear axle (102), at the same time, when the engagement sleeve S2 is engaged, the power is transmitted from the traction gear pair GP3 to the traction gear pair GP4 to the traction gear pair GP5 to the traction gear pair GP6, to provide the power required for driving the front wheels of the front axle (101); and c. (iii) In the power output shaft motor mode: by driving the power output shaft through the second motor M2, when the electric control lever is actuated, the output shaft of the second motor M2 rotates, the power is transmitted from the second motor M2 to the power output shaft gear pair GP8 and the power output shaft gear pair GP11, when the engagement sleeve S3 is engaged with the power output shaft gear pair GP8, the power is transmitted from the power output shaft gear pair GP8 to the power output shaft gear pair GP9, and then to the power output shaft gear pair GP10, to provide power for the middle power output shaft, when the engagement sleeve S4 is engaged with the power output shaft gear pair GP11, the power is directly transmitted through the power output shaft gear pair GP11 to provide power for the rear power output shaft, when the engagement sleeve S3 and the engagement sleeve S4 are engaged with the power output shaft gear pair GP8 and the power output shaft gear pair GP11, the middle power output shaft and the rear power output shaft are both powered.

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