Stepless speed change tractor with power dividing function

Abstract

The utility model relates to a power split stepless speed change tractor which comprises a power driving system, the power driving system comprises an engine, a torsion damper, a generator, a hybrid power box and a driving motor which are connected in sequence, and the engine is connected with a PTO shaft. The PTO shaft sequentially penetrates through a generator shaft of the generator, the hybrid power box and a driving motor shaft of the driving motor, a rear axle input shaft is arranged between the driving motor shaft and the PTO shaft, and a double-planetary gear set is arranged in the hybrid power box. And the motor controller is connected with the generator and the driving motor, and is connected with the energy storage device through a high-voltage junction box. The tractor can work in multiple modes and is located in a working area with good economical efficiency in real time. The electric stepless speed change and the increase of the torque of the wheel end are realized, so that the power requirement of the tractor for operation under different working conditions is met, and the operation intensity is reduced; secondary recovery of energy is achieved, and fuel economy is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hybrid tractors, and particularly relates to a continuously variable transmission tractor with power split. Background Art

[0002] Traditional tractors use diesel engines as the sole power source. During the operation of agricultural implements driven by the PTO, due to the uncertainties of the loads on the running gear and the PTO operation, the working point of the engine often fluctuates greatly. The single power source cannot precisely control the power distribution between the two, increasing the exhaust emission problem of the tractor, reducing the working efficiency of the engine, and being unable to achieve energy recovery for secondary recycling of energy. At the same time, to achieve a large driving speed range and increase the adaptability of matching agricultural implements, a multi-gear gearbox is usually adopted, resulting in the driver needing to shift gears frequently and continuously, unable to achieve flexible speed change, and with a large labor intensity. Therefore, the development of new energy tractors is of great significance for achieving energy conservation and emission reduction and reducing the operation intensity. Summary of the Utility Model

[0003] The technical problem to be solved by the utility model is to provide a continuously variable transmission tractor with power split, which can work in multiple modes through a hybrid power drive system and is always in a working area with better economy; realizes electric continuously variable transmission and increases the torque at the wheel end to meet the power requirements of the tractor under different working conditions, reducing the operation intensity; realizes the secondary recovery of energy and improves the fuel economy.

[0004] To solve the above problems, the technical solution adopted by the utility model is:

[0005] A continuously variable transmission tractor with power split, which includes a power drive system. The power drive system includes an engine, a torsional damper, a generator, a hybrid box, and a drive motor connected in sequence. The engine is connected to the PTO shaft, and the PTO shaft passes through the generator shaft of the generator, the hybrid box, and the drive motor shaft of the drive motor in sequence. A rear axle input shaft is arranged between the drive motor shaft and the PTO shaft, and a double planetary gear set is arranged in the hybrid box; it also includes a motor controller connected to the generator and the drive motor, and the motor controller is connected to an energy storage device through a high-voltage distribution box;

[0006] The flywheel of the engine is arranged in the engine flywheel housing, the generator is arranged in the generator housing, the drive motor is arranged in the drive motor housing. A transition plate is arranged between the engine flywheel housing and the generator housing, and the engine flywheel housing, the transition plate, the generator housing, the hybrid box, and the drive motor housing are bolted together through flange plates; the torsional damper is bolted to the flywheel, and the PTO shaft is connected to the torsional damper through a spline.

[0007] As an embodiment of the present utility model, a lubricating oil port of the hybrid box is provided at the upper end of the hybrid box. Cooling oil inlet ports are provided at the upper end and both sides of the generator housing and the drive motor housing, and a cooling oil sump is provided at the lower part. A cooling oil outlet is provided at the bottom of the cooling oil sump. The cooling oil outlet is connected to a cooling radiator, and the cooling radiator is connected to the cooling oil inlet port and the lubricating oil port of the hybrid box through an oil pump.

[0008] As an embodiment of the present utility model, the double planetary gear set includes an input gear of the hybrid box, a generator gear, a drive motor gear, a reduction gear, and an output gear of the hybrid box. The input gear of the hybrid box, the generator gear, and the drive motor gear form a planetary gear set. Among them, the input gear of the hybrid box is a planet gear, which is fixed on the PTO shaft through a spline. The generator gear is a sun gear, which is fixed on the generator shaft through a spline. The drive motor gear is a ring gear, which is fixed on the drive motor shaft through a spline. The drive motor gear, the reduction gear, and the output gear of the hybrid box form a planetary gear set. The output gear of the hybrid box is a sun gear, which is fixed on the rear axle input shaft through a spline. The reduction gear is a planet gear, which is arranged on the rear axle input shaft through a needle bearing.

[0009] As an embodiment of the present utility model, the rear axle input shaft is connected to a reduction box, and the reduction box is respectively connected to the rear axle and the front axle for outputting power to the wheels. The PTO shaft is connected to a PTO gearbox for outputting power to agricultural implements.

[0010] As an embodiment of the present utility model, the PTO shaft passes through the reduction box and the rear axle in sequence and is connected to the PTO gearbox. A PTO wet clutch is arranged between the reduction box and the rear axle on the PTO shaft. A rear-end transition housing is arranged between the drive motor housing and the reduction box. The drive motor housing, the rear-end transition housing, the reduction box, and the rear axle are bolted together through flange plates.

[0011] As an embodiment of the present utility model, the high-voltage distribution box is respectively connected to a 24V DC-DC converter and a 220V / 380V DC-AC converter, and the 24V DC-DC4 is connected to the low-voltage 24V battery of the whole machine.

[0012] As an implementation manner of the present utility model, the energy storage device is a power battery or a super capacitor with a high voltage of 380V - 600V; the 24V DC - DC converter draws power from the energy storage device and converts it into a low voltage of 24V, which can be used to replace the low - voltage 24V battery of the whole machine or charge the low - voltage 24V battery of the whole machine; the 220V / 380V DC - AC converter draws power from the energy storage device and converts it into a voltage of 220V / 380V for disaster relief, field welding or daily power demand.

[0013] As an implementation manner of the present utility model, the motor controller is a dual - motor controller or two single - motor controllers.

[0014] As an implementation manner of the present utility model, the engine flywheel housing, transition plate, generator housing, hybrid box housing, drive motor housing, rear - end transition housing, reduction box housing, and the housings of the rear axle and front axle all adopt load - bearing housings.

[0015] The beneficial effects produced by adopting the above - mentioned technical solutions are as follows:

[0016] The continuously variable transmission tractor with power split provided by the present utility model can work in multiple modes such as electric mode, range - extender mode, hybrid mode, and direct - drive mode through a hybrid power drive system, enabling the tractor to always operate in a region with better economy under various working conditions; the drive motor connected to the double planetary gear set in the hybrid box realizes stepless electric speed change and increases the torque at the wheel end, which can meet the power requirements of the tractor under different working conditions and reduce the operation intensity. The secondary recovery of energy is achieved through the generator and the energy storage device, improving the fuel economy.

[0017] The hybrid box, generator, and drive motor share the oil. The oil is sprayed into the motor windings and gears from the cooling radiator under the action of the oil pump, enters the cooling oil sump, and is connected to the cooling radiator through the cooling oil outlet, realizing heat dissipation through reciprocating circulation, and reducing the lubrication system of the power assembly.

[0018] The engine does not need to be equipped with a starter. The energy storage device provides power to run the generator to start the engine, saving space, reducing production costs, reducing components, and facilitating later maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the present utility model.

[0020] Figure 2 is a structural schematic diagram of the power drive system in the present utility model.

[0021] Figure 3 isFigure 2 Partial enlarged schematic diagram at location A in the middle.

[0022] Wherein: 1 - generator; 2 - generator shaft; 3 - energy storage device; 4 - 24V DC - DC converter; 5 - high - voltage distribution box; 6 - 220V / 380V DC - AC converter; 7 - motor controller; 8 - hybrid transmission case; 9 - drive motor; 10 - drive motor shaft; 11 - reduction gearbox; 12 - PTO wet clutch; 13 - PTO shaft; 20 - torsional damper; 21 - engine; 22 - whole - machine low - voltage 24V battery; 23 - engine flywheel housing; 24 - transition plate; 25 - generator housing; 26 - drive motor housing; 27 - rear - end transition housing; 28 - rear axle input shaft; 29 - lubricating oil port of hybrid transmission case; 30 - cooling oil inlet; 31 - cooling oil outlet; 32 - cooling oil sump; 33 - oil - cooled radiator; 34 - reduction gear; 35 - drive motor gear; 36 - output gear of hybrid transmission case; 37 - input gear of hybrid transmission case; 38 - generator gear; 39 - flywheel. Specific embodiments

[0023] To make the objectives, technical solutions and advantages of the present utility model clearer, the following describes the utility model clearly and completely with reference to specific embodiments.

[0024] As Figure 1 and Figure 2 shown, a continuously variable transmission tractor with power split includes a power drive system. The power drive system includes an engine 21, a torsional damper 20, a generator 1, a hybrid transmission case 8 and a drive motor 9 connected in sequence. The engine 21 is connected to the PTO shaft 13, and the PTO shaft 13 passes through the generator shaft 2 of the generator 1, the hybrid transmission case 8 and the drive motor shaft 10 of the drive motor 9 in sequence. A rear axle input shaft 28 is provided between the drive motor shaft 10 and the PTO shaft 13, and a double planetary gear set is provided in the hybrid transmission case 8; It also includes a motor controller 7 connected to the generator 1 and the drive motor 9, and the motor controller 7 is connected to the energy storage device 3 through a high - voltage distribution box 5;

[0025] The flywheel 39 of the engine 21 is arranged in the engine flywheel housing 23, the generator 1 is arranged in the generator housing 25, the drive motor 9 is arranged in the drive motor housing 26. A transition plate 24 is provided between the engine flywheel housing 23 and the generator housing 25. The engine flywheel housing 23, the transition plate 24, the generator housing 25, the hybrid transmission case 8 and the drive motor housing 26 are connected together by flange bolts; The torsional damper 20 is bolt - fixed on the flywheel 39, and the PTO shaft 13 is connected to the torsional damper 20 through a spline, and the rotational speed of the PTO shaft 13 is synchronous with that of the engine 21.

[0026] The continuously variable transmission tractor with power split can work in multiple modes such as electric mode, range extender mode, hybrid mode, and direct drive mode through a hybrid powertrain system, enabling the tractor to operate in the region with better economy in real time under various working conditions; the drive motor 9 connected to the double planetary gear set in the hybrid box 8 realizes stepless electric speed change and increases the torque at the wheel end, which can meet the power requirements of the tractor under different working conditions and reduce the operation intensity. The generator 1 and the energy storage device 3 realize secondary energy recovery and improve fuel economy.

[0027] As Figure 2 shown, a hybrid box lubricating oil port 29 is provided at the upper end of the hybrid box 8, cooling oil inlet ports 30 are provided at the upper ends and both sides of the generator housing 25 and the drive motor housing 26, a cooling oil sump 32 is provided at the lower part, the bottom of the hybrid box 8 is communicated with the cooling oil sump 32, a cooling oil outlet 31 is provided at the bottom of the cooling oil sump 32, the cooling oil outlet 31 is connected to the cooling radiator 33, and the cooling radiator 33 is connected to the cooling oil inlet port 30 and the hybrid box lubricating oil port 29 through an oil pump. The hybrid box 8, the generator 1, and the drive motor 9 share the oil fluid. The oil fluid is sprayed into the motor windings and gears from the cooling radiator 23 under the action of the oil pump, enters the cooling oil sump 32, and is connected to the cooling radiator 33 through the cooling oil outlet 31, and circulates reciprocally to achieve heat dissipation, and the lubrication system of the powertrain is reduced.

[0028] As Figure 3 shown, the double planetary gear set includes a hybrid box input gear 37, a generator gear 38, a drive motor gear 35, a reduction gear 34, and a hybrid box output gear 36; the hybrid box input gear 37, the generator gear 38, and the drive motor gear 35 form a planetary gear set, where the hybrid box input gear 37 is a planet gear, fixed to the PTO shaft 13 through a spline, the generator gear 38 is a sun gear, fixed to the generator shaft 2 through a spline, and the drive motor gear 35 is a ring gear, fixed to the drive motor shaft 10 through a spline; the drive motor gear 35, the reduction gear 34, and the hybrid box output gear 36 form a planetary gear set, the hybrid box output gear 36 is a sun gear, fixed to the rear axle input shaft 28 through a spline, and the reduction gear 34 is a planet gear, arranged on the rear axle input shaft 28 through a needle bearing.

[0029] The rear axle input shaft 28 is connected to the reduction gearbox 11, and the reduction gearbox 11 is connected to the rear axle and the front axle through the rear drive shaft and the front drive shaft respectively, for outputting power to the rear wheels and the front wheels; the PTO shaft 13 is connected to the PTO gearbox, for outputting power to the farm implements.

[0030] Specifically, the PTO shaft 13 passes through the reduction gearbox 11 and the rear axle in sequence and is connected to the PTO gearbox. A PTO wet clutch 12 is arranged on the PTO shaft 13 between the reduction gearbox 11 and the rear axle. A rear-end transition housing 27 is arranged between the drive motor housing 26 and the reduction gearbox 11. The drive motor housing 26, the rear-end transition housing 27, the reduction gearbox 11 and the rear axle are connected together by flange bolts.

[0031] The high-voltage distribution box 5 is respectively connected to the 24V DC-DC converter 4 and the 220V / 380V DC-AC converter 6. The 24V DC-DC 4 is connected to the 24V battery 22 of the whole machine at low voltage. The energy storage device 3 is a power battery or a super capacitor with a high voltage of 380V - 600V. The 24V DC-DC converter 4 draws power from the energy storage device 3 and converts it into 24V low voltage, which can be used to replace the 24V battery 22 of the whole machine at low voltage to provide 24V low voltage for the whole machine, or can charge the 24V battery 22 of the whole machine at low voltage to meet the low-voltage power demand of the whole machine. The 220V / 380V DC-AC converter 6 draws power from the energy storage device 3 and converts it into 220V / 380V voltage for disaster relief, field welding or daily power demand.

[0032] In this embodiment, the motor controller 7 is a dual-motor controller or two single-motor controllers. The engine flywheel housing 23, the transition plate 24, the generator housing 25, the housing of the hybrid box 8, the drive motor housing 26, the rear-end transition housing 27, the housing of the reduction gearbox 11, the rear axle and the housing of the front axle all adopt load-bearing housings.

[0033] There are two optimization methods for the power drive system in this embodiment: 1) The generator on the engine 21 can be removed, and the 24V battery 22 of the whole machine at low voltage can be removed. The low-voltage power consumption of the whole machine is provided by the energy storage device 3. When the power of the energy storage device 3 is insufficient, the engine 21 reduces the output power and increases the power generation power of the generator 1 to supply power to the energy storage device 3. 2) The engine 21 does not need to be equipped with a starter. The energy storage device 3 provides power to operate the generator 1 to start the engine 21. At this time, the generator 1 is used as a motor. Through the above two optimization methods, space is saved, production costs are reduced, the number of components is reduced, and it is convenient for later maintenance.

[0034] Specific working mode:

[0035] Range-extended mode: When the tractor is starting or in low-speed crawling conditions, the engine 21 and the generator 1 act as power sources to generate electricity. Through the energy storage device 3 and the motor controller 7, stable electric energy is provided to the drive motor 9. The drive motor 9 transmits the power to the rear axle input shaft 28 to drive the tractor to move, giving play to the characteristics of the permanent magnet motor with high torque at low speed. The engine 21 drives the PTO shaft 13 for farming operations. When the power of the drive motor 9 is insufficient, the energy storage device 3 distributes power to the generator 1, and the generator 1 acts as a motor to provide power.

[0036] Pure electric mode: The energy storage device 3 serves as the power source and directly supplies power to the drive motor 9. The drive motor 9 converts the electric energy into mechanical energy to realize the operation and movement of the tractor. This mode is divided into two forms: light hybrid and heavy hybrid according to the power ratio of the energy storage device 3. When the power of the energy storage device 3 accounts for 5%-10% of the tractor power, it is the light hybrid mode. In this mode, when the engine 21 suddenly fails or runs out of fuel, the tractor can walk for a short time to a repairable location and a refueling place for use, and the PTO does not work. When the power of the energy storage device 3 accounts for 30%-50% of the tractor power, it is the heavy hybrid mode. In this mode, the energy storage device 3 directly supplies power to the drive motor 9, and the drive motor 9 can work for a long time to meet the operation requirements of small-load conditions such as road transportation, achieving energy conservation and environmental protection.

[0037] Hybrid mode: When the vehicle speed in the operating condition is running at 7-12 km / h, the power of the engine 21 is shunted through the hybrid box 8. Part of the power of the engine 21 is used for the generator 1 to generate electricity, and the generated electric energy is provided to the energy storage device 3 for driving the rotation of the drive motor 9; part of the power is directly transmitted to the wheels for vehicle movement. At this time, the wheel torque consists of two parts: the engine torque and the drive motor torque. The drive motor 9 provides the vehicle speed, giving full play to the constant power characteristics of the engine 21 and the drive motor 9.

[0038] The vehicle controller VCU controls the power distribution. When the energy storage device 3 is fully charged, the engine 21 does not generate electricity, and all the power is provided to the reduction gearbox 11 for traction operation. If PTO rotation operation is required at this time, the vehicle controller VCU controls the engine 21 to perform power distribution. Part of the power of the engine 21 is used for generating electricity, and the generated electricity is used to supply the drive motor 9. The drive motor 9 is responsible for the vehicle movement, and the other part of the power of the engine 21 is used for the rotation operation of the PTO shaft 13.

[0039] Direct drive mode: When the operating speed of the tractor is in the range of 12 - 20 km / h during operation, the motor 9 is driven into the constant power state according to the motor characteristic curve. The higher the speed, the smaller the torque. At this time, the engine 21 transmits the torque to the wheels through the reduction gearbox 11 to achieve the direct drive mode. At the wheel end, the engine 21 provides the torque and the drive motor 9 provides the vehicle speed, jointly performing traction operations at high speeds. At this time, the engine 21 is still in the high-efficiency range, without the gear transmission of a mechanical tractor, and the working efficiency is high. If the tractor does not need to move, in the direct drive mode, all the power of the engine 21 is used for the PTO shaft 13 for farming operations and does not need to provide power to the generator 1 for power generation; if the tractor needs to move, in the direct drive mode, a part of the power of the engine 21 is used for the generator 1 to generate electricity.

[0040] Since the electric energy of the energy storage device 3 is consumed during the driving and operation of the tractor, when the tractor stops but the engine is not turned off, the power of the engine 21 is used for the generator 1 to generate electricity.

[0041] When the tractor brakes, it is equivalent to the power drive system of the tractor driving the generator 1 to generate electricity in reverse, and the drive motor 9 can also be used as a generator to generate electricity. If the PTO is in the working state when the tractor stops without turning off the engine or brakes, and the electric energy of the energy storage device 3 is not full, a part of the power of the engine 21 is used to generate torque for the PTO shaft 13, and the remaining power drives the generator 1 to generate electricity.

[0042] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A stepless variable speed tractor with power split, characterized in that: It includes a power drive system, which includes an engine, a torsional damper, a generator, a hybrid box, and a drive motor connected in sequence. The engine is connected to the PTO shaft, and the PTO shaft passes through the generator shaft of the generator, the hybrid box, and the drive motor shaft of the drive motor in sequence. A rear axle input shaft is arranged between the drive motor shaft and the PTO shaft, and a double planetary gear set is arranged in the hybrid box; it also includes a motor controller connected to the generator and the drive motor, and the motor controller is connected to the energy storage device through a high-voltage distribution box; The flywheel of the engine is arranged in the engine flywheel housing, the generator is arranged in the generator housing, the drive motor is arranged in the drive motor housing, a transition plate is arranged between the engine flywheel housing and the generator housing, and the engine flywheel housing, the transition plate, the generator housing, the hybrid box, and the drive motor housing are bolted together through flange plates; the torsional damper is bolted to the flywheel, and the PTO shaft is connected to the torsional damper through a spline.

2. A stepless variable speed tractor with power splitting according to claim 1, characterized in that: A hybrid box lubricating oil port is arranged at the upper end of the hybrid box, cooling oil inlet ports are arranged at the upper end and both sides of the generator housing and the drive motor housing, a cooling oil sump is arranged at the lower part, a cooling oil outlet is arranged at the bottom of the cooling oil sump, the cooling oil outlet is connected to a cooling radiator, and the cooling radiator is connected to the cooling oil inlet port and the hybrid box lubricating oil port through an oil pump.

3. The continuously variable transmission tractor with power split according to claim 2, characterized in that: The double planetary gear set includes a hybrid box input gear, a generator gear, a drive motor gear, a reduction gear, and a hybrid box output gear; The hybrid box input gear, the generator gear, and the drive motor gear form a planetary gear set. Among them, the hybrid box input gear is a planet gear, fixed to the PTO shaft through a spline, the generator gear is a sun gear, fixed to the generator shaft through a spline, and the drive motor gear is a ring gear, fixed to the drive motor shaft through a spline; The drive motor gear, the reduction gear, and the hybrid box output gear form a planetary gear set. The hybrid box output gear is a sun gear, fixed to the rear axle input shaft through a spline, and the reduction gear is a planet gear, arranged on the rear axle input shaft through a needle roller bearing.

4. A continuously variable transmission tractor with power split according to claim 3, characterized in that: The rear axle input shaft is connected to a reduction gearbox, and the reduction gearbox is connected to the rear axle and the front axle respectively, for outputting power to the wheels; the PTO shaft is connected to a PTO gearbox, for outputting power to agricultural implements.

5. A continuously variable transmission tractor with power split according to claim 4, characterized in that: The PTO shaft passes through the reduction gearbox and the rear axle in sequence and is connected to the PTO gearbox. A PTO wet clutch is arranged on the PTO shaft between the reduction gearbox and the rear axle; a rear-end transition housing is arranged between the drive motor housing and the reduction gearbox, and the drive motor housing, the rear-end transition housing, the reduction gearbox, and the rear axle are bolted together through flange plates.

6. A continuously variable transmission tractor with power split according to any one of claims 1-5, characterized in that: The high-voltage distribution box is respectively connected to a 24V DC-DC converter and a 220V / 380V DC-AC converter, and the 24V DC-DC (4) is connected to the 24V battery of the whole machine at low voltage.

7. A stepless variable speed tractor with power split according to claim 6, characterized in that: The energy storage device is a power battery or a super capacitor with a high voltage of 380V - 600V; the 24V DC-DC converter draws power from the energy storage device and converts it into a low voltage of 24V, which can be used to replace the low-voltage 24V battery of the whole machine or charge the low-voltage 24V battery of the whole machine; the 220V / 380V DC-AC converter draws power from the energy storage device and converts it into a voltage of 220V / 380V for disaster relief, field welding or daily power consumption needs.

8. A stepless variable speed tractor with power split according to claim 1, characterized in that: The motor controller is a dual-motor controller or two single-motor controllers.

9. A stepless variable speed tractor with power split according to claim 4, characterized in that: The engine flywheel housing, transition plate, generator housing, hybrid box housing, drive motor housing, rear-end transition housing, reduction box housing, and the housings of the rear axle and front axle all adopt load-bearing housings.

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