Powertrain and tractor

Abstract

The embodiments of the present application relate to the technical field of power transmission. Disclosed are a powertrain and a tractor. The powertrain can be applied to new energy architectures. The powertrain comprises a first electric motor, a second electric motor, and a gearbox, which comprises a first driveshaft, a second driveshaft, a rear axle driveshaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear and at least one second driven gear, wherein the rear axle driveshaft is configured to connect to a rear axle; one end of the first driveshaft is configured to connect to a power take-off, and the other end of the first driveshaft is connected to the first electric motor; the first driveshaft is connected to the first driving gear; the second driveshaft is connected to the second electric motor; the second driveshaft is connected to each second driving gear; the first driving gear meshes with the first driven gear; and each second driving gear meshes with one second driven gear.

Description

Power device and tractor

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202410987458.4, filed on July 23, 2024, the contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application relates to the field of power transmission technology, in particular to a power device and a tractor. BACKGROUND

[0004] With the continuous development of tractor manufacturing technology, various different transmission systems such as uninterrupted power transmission system and stepless variable speed transmission system are applied to the speed change of tractors. Tractors such as harvesters, pulverizers and tractors usually need to provide multiple gears to adapt to the high resistance working conditions of farmland.

[0005] However, in actual transportation, rotary plowing and plowing operation conditions, the selection of the speed and torque of the tractor requires a large difference. Even if the tractor frequently changes gears to adjust the speed, the actual working speed of the engine in the tractor is difficult to be in the optimal speed range. The working speed of the tractor cannot adapt to the actual working conditions, and thus the tractor cannot work at high power, resulting in poor reliability of the tractor in actual working conditions. In addition, due to the gradual complication of the structure of the transmission system, impact and jerk are prone to occur during gear shifting of the tractor, and tire slip is prone to occur, further resulting in poor reliability of the tractor in actual working conditions. According to the development trend of tractors and other equipment, new energy architectures have a certain scale, and power devices such as pure electric, extended-range electric, hybrid, fuel cell electric, and hydrogen engine will be widely applied to tractors. Therefore, the optimization and improvement of the present technical solution are also adapted to new energy architectures, achieving energy saving and emission reduction while solving the problem of poor reliability of the tractor in actual working conditions in the prior art.

[0006] SUMMARY

[0007] The purpose of the embodiments of the present application is to provide a power device and a tractor, which solves the problem of poor reliability of the tractor in actual working conditions in the prior art.

[0008] To achieve the above-mentioned purpose, the first aspect of the present application provides a power device, which comprises a first electric motor, a second electric motor and a gearbox, the gearbox comprising a first transmission shaft, a second transmission shaft, a rear axle transmission shaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear and at least one second driven gear, the number of second driving gears being the same as that of second driven gears;

[0009] The rear axle transmission shaft is used for connecting the rear axle, one end of the first transmission shaft is used for connecting the power output device, the other end of the first transmission shaft is connected with the first motor, the first transmission shaft is connected with the first driving gear, the second transmission shaft is connected with the second motor, the second transmission shaft is connected with each second driving gear, the first driving gear is engaged with the first driven gear, and each second driving gear is engaged with a second driven gear respectively;

[0010] The first power transmission structure is used for being connected with the first driven gear to transmit the power of the first motor.

[0011] The second power transmission structure is used for being connected with any one of the second driven gears to transmit the power of the second motor.

[0012] In the embodiment of the application, the gear diameters of each second driving gear are different, and the gear diameters of each second driven gear are different.

[0013] Each second driving gear is engaged with each second driven gear in the order of gear diameter from large to small and in the order of gear diameter from small to large.

[0014] In the embodiment of the application, the second power transmission structure used for being connected with any one of the second driven gears to transmit the power of the second motor comprises:

[0015] The second power transmission structure is used for being connected with the second driven gear corresponding to the target speed range to transmit the power of the second motor, wherein the target speed range is determined according to the gear diameters of the second driving gears and the gear diameters of the second driven gears.

[0016] In the embodiment of the application, the power device further comprises a power supply device.

[0017] The power supply end of the power supply device is connected with the first motor and the second motor, and the first motor is arranged on one side of the second motor.

[0018] In the embodiment of the application, the power device further comprises a diesel engine and a generator.

[0019] The diesel engine is connected with the charging end of the power supply device through the generator.

[0020] The diesel engine is used for supplying energy to the generator.

[0021] The generator is used for charging the power supply device.

[0022] In the embodiment of the application, the power device further comprises a rectifier, an inverter and an electric energy controller.

[0023] The generator is connected with a charging end of the power supply device through a rectifier, and a power supply end of the power supply device is connected with the first motor and the second motor through an inverter, and the electric energy controller is connected with the rectifier and the inverter;

[0024] The rectifier is used for converting alternating current output by the generator into direct current to charge the power supply device;

[0025] The electric energy controller is used for generating a control signal according to the current control parameters of the first motor and the second motor, and sending the control signal to the inverter;

[0026] The inverter is used for converting direct current output by the power supply end of the power supply device into alternating current corresponding to the current control parameters to supply power to the first motor and the second motor respectively in response to the control signal.

[0027] In the embodiment of the application, the power device further comprises a four-wheel drive driving gear, a four-wheel drive driven gear, a four-wheel drive transmission shaft and a four-wheel drive clutch;

[0028] One end of the four-wheel drive clutch is used for connecting the front axle, and the other end of the four-wheel drive clutch is connected with the four-wheel drive transmission shaft;

[0029] The four-wheel drive transmission shaft is connected with the four-wheel drive driven gear, the four-wheel drive driving gear is engaged with the four-wheel drive driven gear, and the four-wheel drive driving gear is connected with the rear axle transmission shaft.

[0030] In the embodiment of the application, the first power transmission structure is further used for connecting with the first driven gear in the case that the second power transmission structure is connected with any one of the second driven gears.

[0031] In the embodiment of the application, the first power transmission structure is used for connecting with the first driven gear to transmit the power of the first motor, comprising:

[0032] The first power transmission structure is used for connecting with the first driven gear to transmit the power of the first motor in the case that the speed difference between the first driving gear and the rear axle transmission shaft is less than a preset difference value;

[0033] The second power transmission structure is used for connecting with any one of the second driven gears to transmit the power of the second motor, comprising:

[0034] The second power transmission structure is used for connecting with any one of the second driven gears to transmit the power of the second motor in the case that the speed difference between the second driving gear and the rear axle transmission shaft is less than a preset difference value.

[0035] The second aspect of the application provides a tractor, which comprises a front axle, a rear axle, a power output device and the above-mentioned power device;

[0036] The power device is connected with the front axle, the rear axle and the power output device.

[0037] The power device comprises a first motor, a second motor, a gearbox, the gearbox comprising a first transmission shaft, a second transmission shaft, a rear axle transmission shaft, a first power transmission structure, a second power transmission structure, a first gear main gear, a first gear driven gear, at least one second gear main gear and at least one second gear driven gear; the rear axle transmission shaft is used for connecting the rear axle, one end of the first transmission shaft is used for connecting the power output device, the other end of the first transmission shaft is connected with the first motor, the first transmission shaft is engaged with the first gear main gear, the second transmission shaft is connected with the second motor, the second transmission shaft is engaged with each second gear main gear, the first gear main gear is engaged with the first gear driven gear, and each second gear main gear is engaged with one second gear driven gear. The power of the first motor and the second motor is coupled and output through gear transmission, and through matching of the torques of the first motor and the second motor, the torque can be smoother, gear shifting impact and jerk during load change can be avoided, and the reliability of the tractor is improved. Meanwhile, through adjustment of the output of the motor, accurate stepless speed change is realized, the efficient range of the motor is effectively utilized, and the efficiency of the tractor is improved, so that the tractor has higher reliability.

[0038] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation part to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0040] Fig. 1 schematically shows a first structure schematic diagram of a power device according to an embodiment of the present application;

[0041] Fig. 2 schematically shows a partial structure schematic diagram of a power device according to an embodiment of the present application;

[0042] Fig. 3 schematically shows a second structure schematic diagram of a power device according to an embodiment of the present application;

[0043] Fig. 4 schematically shows a structure schematic diagram of a tractor according to an embodiment of the present application.

[0044] BRIEF DESCRIPTION OF DRAWINGS

[0045] 1000 - tractor; 10 - power device, 20 - power output device, 30 - rear axle, 40 - front axle; 100 - first electric motor, 200 - second electric motor, 300 - gearbox, 400 - power supply device, 500 - diesel engine, 600 - generator, 700 - rectifier, 800 - inverter, 900 - electric energy controller, 301 - first transmission shaft, 302 - second transmission shaft, 303 - rear axle transmission shaft, 304 - first power transmission structure, 305 - second power transmission structure, 306 - first driving gear, 307 - first driven gear, 308 - second driving gear, 309 - second driven gear, 310 - four-wheel drive driving gear, 311 - four-wheel drive driven gear, 312 - four-wheel drive transmission shaft, 313 - four-wheel drive clutch, 3081 - high-speed gear driving gear, 3082 - low-speed gear driving gear, 3091 - high-speed gear driven gear, 3092 - low-speed gear driven gear. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain and illustrate the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0047] It should be noted that if the embodiments of the present application involve directional indications (such as one side and adjacent, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications also change accordingly.

[0048] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is also not within the scope of protection claimed by the present application.

[0049] The power transmission system of middle and large tractors mainly adopts power shift technology, and some tractors adopt CVT (Continuously Variable Transmission) stepless speed change technology. However, the power system structure of CVT stepless speed change is complex, and the manufacturing and maintenance requirements are very high. The tractors have high load, high energy consumption and high emission during plowing and ditching operations, and the pure electric drive of a single motor is limited by the current battery technology and cannot be used in long-term heavy load working conditions.

[0050] In order to adapt to the heavy load working condition of hybrid tractors, for example, the front and rear axles are driven by an electric motor, and the power output device is driven by a diesel engine, so as to realize the diesel-electric hybrid drive of the tractor. However, when the diesel engine drives the power output device to work, a large amount of energy is wasted, which causes the tractor to not meet the requirements of energy saving and emission reduction.

[0051] Without using the CVT stepless speed change power system, in order to adapt to the heavy load working condition of the tractor, the power system not only includes an engine, a motor and a transmission system, but also includes other complex device structures such as a planetary gear train. The excessive complex device structure in the power system leads to unreasonable space arrangement of the parallel arrangement of the walking motor and the PTO (Power Take-Off) motor, which cannot meet the installation requirements of the minimum wheel span of the whole tractor and the cab. In addition, when the operation load is large, the power system cannot continuously improve the output power to overcome the operation load, and there is a weak situation. The whole arrangement of the power system cannot meet the position requirement of the PTO shaft and the walking driving shaft, and resonance and uneven power transmission are prone to occur. The walking power output mode is single, and the adaptability to large load change working conditions is poor.

[0052] Please refer to FIG. 1, which schematically shows a first structure diagram of a power device according to an embodiment of the present application.

[0053] The power device 10 in FIG. 1 includes a first electric motor 100, a second electric motor 200 and a gearbox 300. The gearbox 300 includes a first transmission shaft 301, a second transmission shaft 302, a rear axle transmission shaft 303, a first power transmission structure 304, a second power transmission structure 305, a first driving gear 306, a first driven gear 307, at least one second driving gear 308 and at least one second driven gear 309. The number of the second driving gears 308 is the same as that of the second driven gears 309.

[0054] The rear axle transmission shaft 303 is used to connect the rear axle, one end of the first transmission shaft 301 is used to connect the power output device, the other end of the first transmission shaft 301 is connected with the first motor 100, the first transmission shaft 301 is connected with the first driving gear 306, the second transmission shaft 302 is connected with the second motor 200, and the second transmission shaft 302 is connected with each second driving gear 308, the first driving gear 306 is engaged with the first driven gear 307, and each second driving gear 308 is engaged with a second driven gear 309;

[0055] The first power transmission structure 304 is used to be connected with the first driven gear 307 to transmit the power of the first motor 100.

[0056] The second power transmission structure 305 is used to be connected with any one of the second driven gears 309 to transmit the power of the second motor 200.

[0057] The power device 10 in the embodiment is applied to a tractor of a new energy architecture to drive the tractor to walk or drive the tractor to work. The power device 10 in the embodiment includes a gearbox 300 and coaxially arranged first and second motors 100 and 200. Compared with a single driving motor, the coaxial double-drive motor improves the efficiency of the tractor.

[0058] The gearbox 300 includes a first transmission shaft 301, a second transmission shaft 302, and a rear axle transmission shaft 303. The power of the first motor 100 is transmitted through the first transmission shaft 301, and the power of the second motor 200 is transmitted through the second transmission shaft 302. In the embodiment, the first transmission shaft 301 and the second transmission shaft 302 are coaxially arranged, and compared with a double-motor parallel structure, the power device 10 of the application is more compact, so that the spatial arrangement of the tractor is more reasonable.

[0059] The gearbox 300 further includes a first power transmission structure 304, a second power transmission structure 305, a first driving gear 306, a first driven gear 307, at least one second driving gear 308, and at least one second driven gear 309. For the convenience of understanding, only two second driving gears 308 and two second driven gears 309 are shown in the figure. The first transmission shaft 301 is connected with the first driving gear 306 to cooperate with transmission, and then the power of the first motor 100 is transmitted to the power output device 20 or the rear axle transmission shaft 303 through the first transmission shaft 301. Each second driving gear 308 is connected with a second driven gear 309 to cooperate with transmission, and then the power of the second motor 200 is transmitted to the rear axle transmission shaft 303 through the second transmission shaft 302.

[0060] The power device 10 provides multiple speed modes, specifically, can be driven by the first motor 100 alone, can be driven by the second motor 200 alone, and can be driven by the first motor 100 and the second motor 200 together. In the case where the first motor 100 needs to provide power, the first power transmission structure 304 is used to be connected with the first driven gear 307 to transmit the power of the first motor 100. In the case where the second motor 200 needs to provide power, the second power transmission structure 305 is connected with any one of the second driven gears 309 to transmit the power of the second motor 200. It needs to be understood that the types of the first power transmission structure 304 and the second power transmission structure 305 are set according to actual needs, which can be meshing sleeves, wet clutches, synchronizers and the like, which are not limited herein. For the convenience of understanding, the first power transmission structure 304 and the second power transmission structure 305 in the embodiments of the present application are meshing sleeves. The power of the first motor 100 and the second motor 200 is coupled and output through the parallel shaft type gear transmission, which can make the torque more smooth, avoid gear shifting impact and jerk when the load changes, and improve the reliability of the tractor. At the same time, through the torque matching of the first motor 100 and the second motor 200, and through the adjustment of the output of the motor, stepless speed change is realized, accurate stepless speed change is realized, the high efficiency range of the motor is effectively utilized, and the efficiency of the tractor is improved, so that the tractor has higher reliability.

[0061] In the embodiments of the present application, the gear diameters of each second driving gear 308 are different, and the gear diameters of each second driven gear 309 are different.

[0062] Each second driving gear 308 is engaged with each second driven gear 309 in the order of gear diameter from large to small and in the order of gear diameter from small to large.

[0063] When the second driving gear 308 and the second driven gear 309 are matched for transmission, the gear diameter will affect the transmission ratio. In the case where the gear diameters of each second driving gear 308 are different and the gear diameters of each second driven gear 309 are the same, the second power transmission structure 305 is selected to be connected with any one of the second driven gears 309, so that different transmission ratios can be selected for power transmission. Similarly, in the case where the gear diameters of each second driving gear 308 are the same and the gear diameters of each second driven gear 309 are different, the second power transmission structure 305 is selected to be connected with any one of the second driven gears 309, so that different transmission ratios can be selected for power transmission. In the embodiments of the present application, the gear diameters of each second driving gear 308 are different, and the gear diameters of each second driven gear 309 are different.

[0064] Each second driving gear 308 meshes with each second driven gear 309 in order of gear diameter from large to small. As shown in the figure, one of the two second driving gears 308 is a high-speed gear driving gear 3081 with a large gear diameter, and the other is a low-speed gear driving gear 3082 with a small gear diameter. One of the two second driven gears 309 is a high-speed gear driven gear 3091 with a small gear diameter, and the other is a low-speed gear driven gear 3092 with a large gear diameter. Each second driving gear 308 meshes with one second driven gear 309, including the high-speed gear driving gear 3081 with a large gear diameter meshing with the high-speed gear driven gear 3091 with a small gear diameter, and the low-speed gear driving gear 3082 with a small gear diameter meshing with the low-speed gear driven gear 3092 with a large gear diameter. It should be understood that the spatial arrangement of the plurality of second driving gears 308 and the spatial arrangement of the plurality of second driven gears 309 are both set according to actual needs, and can be arranged from large to small, from small to large, or in random order, which is not limited herein.

[0065] In the embodiments of the present application, the second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit the power of the second motor 200, and includes:

[0066] The second power transmission structure 305 is used to connect with the second driven gear 309 corresponding to the target speed range to transmit the power of the second motor 200, wherein the target speed range is determined according to the gear diameter of the second driving gear 308 and the gear diameter of the second driven gear 309.

[0067] In the present example, mode one and mode two are provided when the tractor is running, wherein mode one corresponds to a low-speed gear mode driven by the second motor 200, and mode two corresponds to a high-speed gear mode driven by the second motor 200. For ease of understanding, the first target speed range corresponding to mode one in the embodiments of the present application is 0 to 18 km / h, and the second target speed range corresponding to mode two is 0 to 39.9 km / h. The second power transmission structure 305 is used to connect with the second driven gear 309 corresponding to the target speed range to transmit the power of the second motor 200.

[0068] Specifically, in the case of selecting mode one, only the second power transmission structure 305 is connected with the low-speed gear driving gear 3082 corresponding to the first target speed range, and the first transmission mechanism is not connected with the first driven gear 307. The power of the second motor 200 is transmitted to the rear axle transmission shaft 303 through the second transmission shaft 302, the low-speed gear driving gear 3082, and the low-speed gear driven gear 3092 in sequence, so as to drive the rear axle 30 through the rotation of the rear axle transmission shaft 303. At the same time, by adjusting the output size of the second motor 200, stepless speed change corresponding to the first target speed range is realized.

[0069] In the case of selecting mode two, only the second power transmission structure 305 is connected with the high-speed gear main gear 3081 corresponding to the second target speed range, and the first transmission mechanism is not connected with the first driven gear 307. The power of the second motor 200 is transmitted to the rear axle transmission shaft 303 through the second transmission shaft 302, the high-speed gear main gear 3081 and the high-speed gear driven gear 3091, so as to drive the rear axle 30 through the rotation of the rear axle transmission shaft 303. At the same time, by adjusting the output size of the second motor 200, stepless speed change corresponding to the second target speed range is realized.

[0070] Please refer to Fig. 2, which schematically shows a partial structure diagram of a power device according to an embodiment of the present application.

[0071] In the embodiment of the present application, the power device 10 further comprises an electronic power supply 400;

[0072] The power supply end of the electronic power supply 400 is connected with the first motor 100 and the second motor 200, and the first motor 100 is arranged on one side of the second motor 200.

[0073] It should be understood that the type of the electronic power supply 400 is set according to actual needs, which is not limited herein. For the convenience of understanding, the electronic power supply 400 is a ternary lithium battery pack in the embodiment of the present application. The power supply end of the electronic power supply 400 is connected with the first motor 100 and the second motor 200, and the electronic power supply 400 supplies power to the first motor 100 and the second motor 200 respectively after the tractor is started, thereby driving the tractor to walk or work. In addition, the first motor 100 and the second motor 200 can also be driven by a fuel oil structure such as a diesel engine, so that the power device 10 in the embodiment can be applied to a tractor with a diesel structure, which is not described herein.

[0074] In the embodiment, the first motor 100 and the second motor 200 are arranged adjacent to each other. Compared with the split type double motor structure, the coaxial double drive motor can meet the space arrangement requirements of the power output device 20, the rear axle 30 and the front axle 40 of the tractor, and avoid poor reliability caused by resonance and uneven power transmission, thereby making the power device 10 adapt to the working conditions with large load changes.

[0075] Please refer to Fig. 3, which schematically shows a second structure diagram of a power device according to an embodiment of the present application.

[0076] In the embodiment of the present application, the power device 10 further comprises a diesel engine 500 and a generator 600;

[0077] The diesel engine 500 is connected with the charging end of the electronic power supply 400 through the generator 600;

[0078] The diesel engine 500 is used to power the generator 600;

[0079] The generator 600 is used to charge the power supply device 400.

[0080] The types of the diesel engine 500 and the generator 600 are set according to actual needs, which are not limited herein. The diesel engine 500 is connected to the charging end of the power supply device 400 through the generator 600. The generator 600 is powered by the power supply device 400 to start the generator, and the first motor 100 and / or the second motor 200 are also powered by the power supply device 400 to start the first motor 100 and / or the second motor 200. The diesel engine 500 drives the generator 600 to power the generator 600, and then the generator 600 charges the power supply device 400 to store energy. The driving mode of the tractor adopts the extended range mode, that is, the power supply device 400 is charged by the diesel engine 500 and the generator 600, and the diesel engine 500 does not need to operate under the load working condition of the tractor during operation, but works in the optimal working range of fuel consumption and emission to charge the power supply device 400, thereby achieving energy saving and emission reduction.

[0081] In the embodiment of the application, the power device 10 further comprises a rectifier 700, an inverter 800 and an electric energy controller 900;

[0082] The generator 600 is connected to the charging end of the power supply device 400 through the rectifier 700, the power supply end of the power supply device 400 is connected to the first motor 100 and the second motor 200 through the inverter 800, and the electric energy controller 900 is connected to the rectifier 700 and the inverter 800;

[0083] The rectifier 700 is used to convert the alternating current output by the generator 600 into direct current to charge the power supply device 400;

[0084] The electric energy controller 900 is used to generate a control signal according to the current control parameters of the first motor 100 and the second motor 200, and send the control signal to the inverter 800;

[0085] The inverter 800 is used to convert the direct current output by the power supply end of the power supply device 400 into alternating current corresponding to the current control parameters to power the first motor 100 and the second motor 200, respectively.

[0086] The rectifier 700 is arranged between the generator 600 and the power supply device 400, and the inverter 800 is arranged between the power supply device 400 and the first motor 100 and the second motor 200. The rectifier 700 is used to convert the alternating current output by the generator 600 into direct current to charge the power supply device 400.

[0087] The electric energy controller 900 is a device for managing, monitoring and optimizing electric energy, and in this embodiment, the electric energy controller 900 is used to constitute a battery management system (BMS) of the tractor. The electric energy controller 900 can provide high voltage to high-voltage components in the tractor through the power distribution unit (PDU) of the high-voltage distribution box, and can also communicate with the VCU (Vehicle Control Unit) through the CAN (Controller Area Network) bus. The electric energy controller 900 is used to generate a control signal according to the current control parameters of the first motor 100 and the second motor 200, and send the control signal to the inverter 800. The current control parameters can be the amplitude and frequency of alternating current, etc., which will not be described here. The inverter 800 converts the direct current output by the power supply device 400 into alternating current corresponding to the current control parameters in response to the control signal, to supply power to the first motor 100 and the second motor 200 respectively.

[0088] In the embodiment of the present application, the power device 10 further comprises a four-wheel drive driving gear 310, a four-wheel drive driven gear 311, a four-wheel drive transmission shaft 312 and a four-wheel drive clutch 313.

[0089] One end of the four-wheel drive clutch 313 is used to connect the front axle 40, and the other end of the four-wheel drive clutch 313 is connected to the four-wheel drive transmission shaft 312.

[0090] The four-wheel drive transmission shaft 312 is connected to the four-wheel drive driven gear 311, the four-wheel drive driving gear 310 is connected to the four-wheel drive driven gear 311, and the four-wheel drive driving gear 310 is connected to the rear axle transmission shaft 303.

[0091] The type of the four-wheel drive clutch 313 is set according to actual needs, which is not limited here. For the convenience of understanding, the four-wheel drive clutch 313 in the embodiment of the present application is a wet multi-plate compression clutch. In the case that the four-wheel drive clutch 313 is closed, the power of the rear axle transmission shaft 303 is transmitted to the four-wheel drive transmission shaft 312 through the four-wheel drive driving gear 310 and the four-wheel drive driven gear 311 in turn, so that the four-wheel drive transmission shaft 312 and the rear axle transmission shaft 303 rotate synchronously. According to the actual working condition requirements of the tractor, the tractor is driven in four-wheel drive mode, further improving the reliability of the tractor.

[0092] In the embodiment of the present application, the first power transmission structure 304 is further used to connect the first driven gear 307 in the case that the second power transmission structure 305 is connected to any one of the second driven gears 309.

[0093] In the present example, mode three is provided when the tractor is running, and mode three corresponds to a heavy load mode in which the first motor 100 and the second motor 200 are driven together. When the tractor is performing heavy load work such as traction work, the load is likely to be too large, resulting in a situation in which the power of a single motor does not meet the actual working condition requirements. When the tractor is performing heavy load work, mode three is selected, the second power transmission structure 305 is connected to one of the second driven gears 309, and the first power transmission structure 304 is connected to the first driven gear 307. The power of the first motor 100 and the second motor 200 is coupled and output to the rear axle transmission shaft 303, so that the speed of the tractor is in the low-speed constant torque section of the motor, avoiding gear shifting impact and jerk, and making the torque transmission smooth. It should be understood that the tractor can be driven in reverse by reversing the first motor 100 and / or the second motor 200, which will not be described here.

[0094] In the embodiments of the present application, the first power transmission structure 304 is used to connect with the first driven gear 307 to transmit the power of the first motor 100, and includes:

[0095] The first power transmission structure 304 is used to connect with the first driven gear 307 to transmit the power of the first motor 100 when the speed difference between the first driving gear 306 and the rear axle transmission shaft 303 is less than a preset difference value;

[0096] The second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit the power of the second motor 200, and includes:

[0097] The second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit the power of the second motor 200 when the speed difference between the second driving gear 308 and the rear axle transmission shaft 303 is less than a preset difference value.

[0098] When switching from mode one or mode two to mode three, the first motor 100 adjusts the output to adjust the speed of the first driving gear 306. In the case where the speed difference between the first driving gear 306 and the rear axle transmission shaft 303 is less than a preset difference value, the first power transmission structure 304 is connected to the first driven gear 307 to transmit the power of the first motor 100, while avoiding power interruption.

[0099] In the present example, mode four is provided when the tractor is running, wherein mode four corresponds to a low speed gear mode driven by the first electric motor 100. In the case of selecting mode four, only the first transmission mechanism is connected with the first driven gear 307 to transmit the power of the first electric motor 100 to the rear axle drive shaft 303. It should be understood that the power output device 20 is usually built-in with a clutch, and in the case of closing the clutch, the power of the first electric motor 100 is directly transmitted to the power output device 20 through the first transmission.

[0100] In the case of the operation being in mode four, the tractor only runs at a fixed speed range for stepless speed regulation. When the tractor needs to run at high speed, the second electric motor 200 adjusts the output to adjust the rotation speed of the second driving gear 308. In the case that the rotation speed difference between the second driving gear 308 and the rear axle drive shaft 303 is less than a preset difference, the second power transmission mechanism 305 is connected with the second driven gear 309 to transmit the power of the second electric motor 200, while avoiding power interruption. It should be understood that when the second power transmission mechanism 305 is connected with the second driven gear 309, the first power transmission mechanism 304 can be disconnected from the first driven gear 307 to realize uninterrupted power shifting. Relative to the power transmission system provided with a complex structure such as an electric proportional valve, the power device 10 of the present application can realize uninterrupted power shifting and improve the efficiency of the tractor. At the same time, the torque output of the electric motor improves the shifting smoothness and avoids the jerk feeling during shifting, further improving the reliability of the tractor.

[0101] The application provides a power device 10, which comprises a first motor 100, a second motor 200 and a gearbox 300, the gearbox 300 comprises a first transmission shaft 301, a second transmission shaft 302, a rear axle transmission shaft 303, a first power transmission structure 304, a second power transmission structure 305, a first driving gear 306, a first driven gear 307, at least one second driving gear 308 and at least one second driven gear 309; the rear axle transmission shaft 303 is used for connecting a rear axle, one end of the first transmission shaft 301 is used for connecting a power output device, the other end of the first transmission shaft 301 is connected with the first motor 100, the first transmission shaft 301 is connected with the first driving gear 306, the second transmission shaft 302 is connected with the second motor 200, the second transmission shaft 302 is connected with each second driving gear 308, the first driving gear 306 is engaged with the first driven gear 307, and each second driving gear 308 is engaged with one second driven gear 309. The power of the first motor 100 and the second motor 200 is coupled and output through gear transmission, and through matching of the torques of the first motor 100 and the second motor 200, the torque can be smoother, gear shifting impact and jerk when the load changes can be avoided, and the reliability of the tractor can be improved. Meanwhile, through adjustment of the output of the motor, accurate stepless speed change is realized, the high efficiency range of the motor is effectively utilized, and the efficiency of the tractor is improved, so that the tractor has higher reliability.

[0102] Referring to FIG. 4, FIG. 4 schematically shows a structural schematic diagram of a tractor according to an embodiment of the application.

[0103] The application further provides a tractor 1000, which comprises a front axle 40, a rear axle 30, a power output device 20 and the above power device 10.

[0104] The power device 10 is connected with the front axle 40, the rear axle 30 and the power output device 20.

[0105] The front axle 40 and the rear axle 30 are both power transmission systems of the tractor 1000, and generally, the front axle 40 refers to a drive axle or a steering axle at the front of the tractor 1000, and the rear axle 30 refers to a drive axle or a steering axle at the rear of the tractor 1000.

[0106] The tractor 1000 further comprises a motion execution mechanism and other structural devices, the other structural devices are set according to the type of the tractor 1000, and can be an arm support, a cylinder and the like, which are not limited herein. The type of the tractor 1000 is also set according to actual requirements, and can be a tractor, an excavator, a crane and the like, which are not limited herein. The power output device 20 is used for driving the motion execution mechanism of the tractor 1000 through power provided by the power device 10. The type of the motion execution mechanism is set according to actual requirements, and can be a hydraulic pump, which is not limited herein.

[0107] The tractor 1000 can be driven to walk and work by the power device 10. The first motor 100 and the second motor 200 in the power device 10 can realize stepless speed change by adjusting the output. The torque of the tractor 1000 is smoother and more efficient, and the reliability is higher.

[0108] It should also be noted that the terms "comprising", "containing", or any other variant thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0109] The above is only an embodiment of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A power plant, characterized in that The power device comprises a first motor, a second motor and a gearbox, the gearbox comprises a first transmission shaft, a second transmission shaft, a rear axle transmission shaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear and at least one second driven gear, the number of the second driving gears is the same as that of the second driven gears; The rear axle transmission shaft is used for connecting a rear axle, one end of the first transmission shaft is used for connecting a power output device, the other end of the first transmission shaft is connected with the first motor, the first transmission shaft is connected with the first driving gear, the second transmission shaft is connected with the second motor, the second transmission shaft is connected with each second driving gear, the first driving gear is engaged with the first driven gear, and each second driving gear is engaged with one second driven gear; The first motor and the second motor are coaxially connected in series, and the first motor and the second motor are used for adjusting output for stepless speed change; The first power transmission structure is used for being connected with the first driven gear to transmit power of the first motor; The second power transmission structure is used for being connected with any one of the second driven gears to transmit power of the second motor.

2. The power plant of claim 1, wherein, The gear diameters of the second driving gears are different from each other, and the gear diameters of the second driven gears are different from each other; Each second driving gear is engaged with each second driven gear in the order from large to small according to the gear diameters.

3. The power plant of claim 2, wherein, The second power transmission structure is used for being connected with any one of the second driven gears to transmit power of the second motor, and the second power transmission structure comprises the following steps: The second power transmission structure is used for being connected with the second driven gear corresponding to a target speed range to transmit power of the second motor, wherein the target speed range is determined according to the gear diameters of the second driving gears and the gear diameters of the second driven gears.

4. The power plant of claim 1, wherein, The power device further comprises a power supply device; A power supply end of the power supply device is connected with the first motor and the second motor, and the first motor is arranged on one side of the second motor.

5. The power plant of claim 4, wherein, The power device further comprises a diesel engine and a generator; The diesel engine is connected with a charging end of the power supply device through the generator; The diesel engine is used for supplying power to the generator; The generator is used for charging the power supply device.

6. The power plant of claim 5, wherein, The power device further comprises a rectifier, an inverter and an electric energy controller; The generator is connected with the charging end of the power supply device through the rectifier, the power supply end of the power supply device is connected with the first motor and the second motor through the inverter, and the electric energy controller is connected with the rectifier and the inverter; The rectifier is used for converting alternating current output by the generator into direct current to charge the power supply device; The electric energy controller is used for generating a control signal according to current control parameters of the first motor and the second motor, and sending the control signal to the inverter. The inverter is configured to convert direct current output by the power supply end of the power supply device into alternating current corresponding to the current control parameter, so as to supply power to the first motor and the second motor respectively.

7. The power plant of claim 1, wherein The power device further comprises a four-wheel drive driving gear, a four-wheel drive driven gear, a four-wheel drive transmission shaft and a four-wheel drive clutch. One end of the four-wheel drive clutch is connected to the front axle, and the other end of the four-wheel drive clutch is connected to the four-wheel drive transmission shaft. The four-wheel drive transmission shaft is connected to the four-wheel drive driven gear, the four-wheel drive driving gear is engaged with the four-wheel drive driven gear, and the four-wheel drive driving gear is connected to the rear axle transmission shaft. The first power transmission structure is further configured to be connected to the first driven gear when the second power transmission structure is connected to any one of the second driven gears.

8. The power plant of claim 1, wherein, The first power transmission structure is configured to be connected to the first driven gear to transmit power of the first motor, comprising:

9. The power plant of claim 1, wherein, The first power transmission structure is configured to be connected to the first driven gear to transmit power of the first motor when a rotational speed difference between the first driving gear and the rear axle transmission shaft is less than a preset difference value. The second power transmission structure is configured to be connected to any one of the second driven gears to transmit power of the second motor, comprising: The second power transmission structure is configured to be connected to any one of the second driven gears to transmit power of the second motor when a rotational speed difference between the second driving gear and the rear axle transmission shaft is less than a preset difference value. The power device comprises a front axle, a rear axle, a power output device and any one of the power devices according to claims 1 to 9.

10. A tractor characterised in that, The power device is connected to the front axle, the rear axle and the power output device. ​

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