Electric drive walking system of tractor

Abstract

The utility model provides an electrically-driven walking system of a tractor. The electrically-driven walking system comprises a front steering drive axle assembly, a rear drive axle assembly, a walking gearbox assembly, a walking drive motor, a first gear shifting motor and a second gear shifting motor. The walking gearbox assembly selectively outputs power of two gears to the front steering drive axle assembly, the walking gearbox assembly outputs power of one gear to the rear drive axle assembly, and the first gear shifting motor is used for switching the drive gear of the front steering drive axle assembly. The second gear shifting motor is used for controlling connection or separation of the rear drive axle assembly and the transmission assembly. According to the four-wheel-drive electric vehicle, electric drive structure arrangement is adopted, the structure is compact, efficiency is high, and accurate control over a motor and fine distribution of power output can be achieved through power output control.

Description

TECHNICAL FIELD

[0001] The utility model belongs to tractor technical field, and specifically is a tractor electric drive walking system. BACKGROUND

[0002] The existing tractor walking system adopts engine, transmission and clutch structure to realize front and rear axle driving running, such as the four-wheel drive system of the tractor disclosed by Chinese patent CN205890549U, which comprises a transmission device, a rear axle differential, a rear drive transmission shaft, a gearbox, a front drive transmission shaft and a front axle differential, the gearbox is in transmission connection with the rear axle differential through the rear drive transmission shaft, the rear axle differential is in transmission connection with the rear axle through the transmission device, the gearbox is integrated with the front axle, the front axle differential is located in the gearbox and is in transmission connection with the gearbox through the front drive transmission shaft, and the front axle differential is in transmission connection with the front axle.

[0003] For example, the novel front and rear drive tractor transmission system disclosed by Chinese patent CN20302218730U comprises a power component, the power component comprises an engine and a transmission box, the engine transmits power to the transmission box through a transmission belt, the transmission box transmits power to a gearbox through a main transmission shaft, a transmission component, the transmission component comprises a front transmission shaft and a rear transmission shaft connected with the gearbox, the front transmission shaft drives the front wheels to rotate through a front axle, the rear transmission shaft drives the rear wheels to rotate through a rear axle, a front main speed reducer is installed in the front axle, and a rear main speed reducer is installed in the rear axle, wherein the tooth number ratio of the front main speed reducer and the rear main speed reducer is equal to the radius ratio of the front wheels and the rear wheels, the gearbox is provided with a front and rear drive separation operating rod, and the front transmission shaft and the rear transmission shaft are connected with the front and rear drive separation operating rod.

[0004] The above structure has some problems: the engine and the gearbox need to be disconnected during gear shifting, which leads to power interruption and affects the use stability; the labor intensity of the mechanical gear shifting tractor operator is large, the use conditions of the wet clutch of the power gear shifting tractor are harsh, and the gear positions are limited; the change of engine speed leads to flow fluctuation, which affects the operation quality and efficiency. In addition, there are two energy conversions in the power transmission process, the mechanical energy is converted into the internal energy of the liquid, and then the internal energy is converted into mechanical energy again, so the energy conversion efficiency is low; the mechanical brake is used frequently and wears out quickly; the traditional mechanical transmission system has a relatively strict relationship with the spatial position relationship of the input and output shafts; the engine output torque and speed fluctuate greatly, and the impact on the transmission system is large. UTILITY MODEL CONTENTS

[0005] The utility model provides a tractor electric drive walking system, adopts electric drive structure arrangement, compact structure, high efficiency. Power output control can realize accurate control of motor and fine distribution of power output.

[0006] A tractor electric drive walking system, comprising a front steering drive axle assembly, a rear drive axle assembly, a walking gearbox assembly, a walking drive motor, a first gear shifting motor and a second gear shifting motor; the walking gearbox assembly selectively outputs power of two gears to the front steering drive axle assembly, and outputs power of one gear to the rear drive axle assembly, the first gear shifting motor is used for switching the drive gear of the front steering drive axle assembly, and the second gear shifting motor is used for controlling the engagement or separation of the rear drive axle assembly and the walking gearbox assembly; the walking gearbox assembly comprises a four-wheel drive clutch, and the four-wheel drive clutch is used for controlling the engagement or separation of the front steering drive axle assembly and the walking gearbox assembly.

[0007] The utility model discloses adopt the mature motor technology, plus the structure simplification, reduced the component of spare part, and the motor drive can realize stepless speed change and reverse operation, satisfy the working condition demand of work.

[0008] Adopt gear shifting motor to shift, carry out the fine control and distribution of power, realize efficient transmission.

[0009] The utility model discloses adopt three gear engagement motor drive, utilize the motor stepless speed regulation and reverse characteristic, reduced gear setting, transmission assembly greatly reduces, volume and cost reduction.

[0010] Adopt gear shifting motor to shift, structure simple, control accurate, shift fast, reduced gear shifting power interruption, power output control can realize the accurate control and fine distribution power output of motor.

[0011] Preferably, the walking gearbox assembly comprises a first shaft, a second shaft, a third shaft and a front output shaft; further comprising an input gear arranged on the first shaft, and the first shaft is connected with the walking drive motor; further comprising a one-gear driving gear, a first gear shifting mechanism, a two-gear driving gear and a three-gear driving gear arranged on the second shaft in sequence; further comprising a one-gear driven gear, a front drive driving gear, a two-gear driven gear and a three-gear driven gear arranged on the third shaft in sequence; the front drive driving gear and the two-gear driven gear are fixedly arranged on the third shaft.

[0012] The rear end of the third shaft is connected with the rear drive axle assembly, the second gear shifting mechanism connected with the second gear shifting motor is arranged on the third shaft, the three-gear driven gear is sleeved on the third shaft, and the second gear shifting mechanism selectively engages or separates from the three-gear driven gear; when the third gear is needed to be used, the second gear shifting mechanism is used to fixedly connect the three-gear driven gear with the third shaft, so as to realize direct driving of the third gear.

[0013] The front output shaft is sleeved with a front drive driven gear, and a four-wheel drive clutch is arranged on the front output shaft for controlling the engagement or disconnection of the front drive driven gear and the front output shaft.

[0014] In the utility model, the first drive gear and the first driven gear are matched, the second drive gear and the second driven gear are matched, the input gear and the third driven gear are matched, the gear ratio walking of three gears is realized, different speed intervals can be corresponded, and each power source can work in an efficient area.

[0015] Preferably, the utility model also includes a variable speed pump assembly for driving the four-wheel drive clutch, the variable speed pump assembly is used for driving the four-wheel drive clutch, and specifically the variable speed pump assembly includes a variable speed pump, a variable speed pump drive motor and an electromagnetic valve, the variable speed pump drive motor is used for driving the variable speed pump, and the electromagnetic valve is used for controlling the on-off of the oil circuit of the four-wheel drive clutch.

[0016] Preferably, the first shaft, the second shaft and the third shaft are arranged in parallel. The structure is simple, the gears are arranged conveniently, and space is saved.

[0017] Preferably, the first gear shifting motor, the second gear shifting motor and the walking drive motor are arranged outside the shell of the walking transmission box assembly. The structure of external control motor is adopted, maintenance and disassembly are facilitated, and cost is low.

[0018] Preferably, the utility model also includes a front transmission shaft and a rear transmission shaft, the front transmission shaft and the rear transmission shaft are both universal shaft structures, one end of the front transmission shaft is connected with the front output shaft and the other end is connected with the front drive axle assembly, and one end of the rear transmission shaft is connected with the third shaft and the other end is connected with the rear drive axle assembly. The universal transmission shaft can effectively balance the unbalanced force in the transmission process, makes the transmission process more stable, and reduces vibration and noise.

[0019] The control method of the utility model discloses a tractor electric drive walking system, which comprises the following steps:

[0020] Step S1: the whole machine is started, the first gear shifting motor is controlled to switch the gear to the first gear, and the four-wheel drive clutch is engaged; at this time, the first gear four-wheel drive mode driving operation mode is driven.

[0021] Step S2: the vehicle speed is acquired in real time, when the vehicle speed is less than the first threshold value V1, the state of step S1 is kept, when the vehicle speed is greater than the first threshold value V1 and less than the second threshold value V2, step S3 is entered, when the vehicle speed is greater than the second threshold value V2, step 4 is entered. 1< Vehicle speed ≤ Second threshold value V2, step S3 is entered; when the vehicle speed is greater than the second threshold value V 2< Vehicle speed, step 4 is entered.

[0022] Step S3: control the first gear motor to switch to second gear, control the four-wheel drive clutch to engage, return to step S2; at this time, the driving operation mode is in the second gear four-wheel drive mode.

[0023] Step S4: control the second gear motor to engage third gear, control the electromagnetic valve to disconnect the four-wheel drive clutch, and return to step S2. At this time, the driving operation mode is in the third gear rear-wheel drive mode, and the power transmission path is: the walking driving motor, the first shaft, the input gear, the third gear driving gear, the third gear driven gear, the second gear mechanism, the third shaft, the rear drive shaft, and the rear drive axle assembly. At this time, the four-wheel drive clutch is disconnected, the first gear shifting mechanism is in the neutral position, and the front axle has no power output.

[0024] The driving control method adopts the four-wheel drive mode in the starting and medium speed regions, has relatively large power, meets the acceleration demand, adopts the rear-wheel drive mode in the high speed stage, and reduces the power, thereby reducing the energy consumption.

[0025] The first threshold V1 is 15 km / h, and the second threshold V2 is 23 km / h.

[0026] In the utility model, the output power of the walking driving motor in step S1 is greater than the output power of the driving motor in step S3, and the output power of the driving motor in step S2 is greater than the output power of the driving motor in step S4. In terms of the control method, the utility model adopts the four-wheel drive mode in the starting and medium speed regions, has relatively large power, meets the acceleration demand, adopts the rear-wheel drive mode in the high speed stage, and reduces the power, thereby reducing the energy consumption.

[0027] In the utility model, the vehicle speed in step S2 is obtained by acquiring the rotating speed signal of the gear in the walking gearbox assembly. The utility model further includes a rotating speed sensor arranged at the outer edge of the first gear driven gear, and the rotating speed sensor is installed at the edge of the gearbox assembly, so that the installation and dismounting are facilitated. The real-time vehicle speed signal is calculated according to the transmission ratio by acquiring the rotating speed sensor, and the structure is simple and the cost is low.

[0028] In steps S1 and S2, the utility model further includes the step that the variable speed pump assembly drives the four-wheel drive clutch 7 to work and controls the engagement of the front steering drive axle assembly and the gearbox assembly. In this step, the front output shaft and the front drive driven gear are power connected, and the power is output to the front transmission shaft.

[0029] In the utility model, the control system further includes an accelerator pedal, a VCU vehicle control unit, an MCU driving motor controller, a first TCU controller, a second TCU controller, the VCU vehicle control unit is electrically connected with the accelerator pedal, the rotating speed sensor, the MCU driving motor controller, the first TCU controller, the second TCU controller, the variable speed pump and the electromagnetic valve.

[0030] In step S1 of the utility model, the VCU vehicle control unit obtains the accelerator pedal signal and the speed sensor signal and then outputs an instruction, controls the first TCU controller to drive the first gear shifting motor to engage the first gear shifting mechanism with gear one, the VCU vehicle control unit controls the variable speed pump driving motor and the electromagnetic valve to make the four-wheel drive clutch engage, and enters the one-gear four-wheel drive mode.

[0031] In step S3 of the utility model, the VCU vehicle control unit obtains the accelerator pedal signal and the speed sensor signal and then outputs an instruction, controls the first TCU controller to drive the first gear shifting motor to engage the first gear shifting mechanism with gear two, the VCU vehicle control unit controls the variable speed pump driving motor and the electromagnetic valve to make the four-wheel drive clutch engage, and enters the two-gear four-wheel drive mode.

[0032] In step S4 of the utility model, the VCU vehicle control unit sends an instruction to control the electromagnetic valve to separate the four-wheel drive clutch and controls the separation of the front steering drive axle assembly and the variable speed assembly. In this step, the front output shaft and the front drive driven gear are separated from power, and the power output of the forward transmission shaft is interrupted.

[0033] Compared with the prior art, the utility model has the following beneficial effects:

[0034] The existing motor technology is mature and widely used, and the structure is simplified, the components are reduced, and the cost is low.

[0035] Operation: the motor is used for operation, gear shifting is rapid, the negative influence caused by power interruption is reduced, the structure is simplified, control is accurate, motor driving can realize stepless speed change and reverse operation, meets the working condition demand of work. It is simple and easy to operate and control.

[0036] Performance: compared with the prior art, since the motor has speed regulation capability, the gear setting can be reduced, only three gears are set, the power interruption caused by gear shifting of the traditional transmission is avoided, and the transmission efficiency can be improved.

[0037] Function: the electric drive arrangement can ensure that each power source works in the high efficiency area, the motor can be used for realizing brake energy recycling, and the wear of the brake system in the prior art is reduced.

[0038] Control method: the utility model adopts the four-wheel drive mode in the starting and medium speed areas, has large power, meets the acceleration demand, adopts the rear drive mode in the high speed stage and reduces the power, and the energy consumption is reduced. DRAWINGS

[0039] Figure 1 It is an internal structure schematic view of the tractor electric drive walking system.

[0040] Figure 2 It is the appearance structure diagram of the tractor electric drive walking system.

[0041] Figure 3 It is the structure enlarged view of the walking gearbox assembly.

[0042] Figure 4 It is the vehicle speed and gear relationship mapping diagram.

[0043] Figure 5 It is the control step flow chart of the control method of the tractor electric drive walking system.

[0044] In the figure: 1-front steering drive axle assembly, 2-rear drive axle assembly, 3-walking gearbox assembly, 301-first shaft, 302-second shaft, 303-third shaft, 304-front output shaft; 301-first shaft, three 305-gear main gear, 306-three gear main gear, 307-one gear main gear, 308-one gear driven gear, 309-first gear shifting mechanism, 310-two gear main gear, 311-two gear driven gear, 312-front drive main gear, 313-front drive driven gear, 314-second gear shifting mechanism, 315-three gear driven gear, 4-walking drive motor, 5-first gear shifting motor, 6-second gear shifting motor, 7-four-wheel drive clutch, 8-speed pump assembly, 801-speed pump, 802-speed pump drive motor, 803-solenoid valve, 9-front transmission shaft, 10-rear transmission shaft, 11-speed sensor, 12-accelerator pedal, 13-VCU vehicle control unit, 14-MCU drive motor controller, 15-first TCU controller, 16-second TCU controller. DETAILED DESCRIPTION

[0045] The utility model makes further explanation in combination with the figures and specific implementation, the schematic embodiment and the explanation thereof of the utility model are used to explain the utility model, and do not constitute improper limitation to the utility model.

[0046] In the description of the utility model, it is understood that the orientation or position relationship indicated by the terms "left", "right", "up", "down", "front", "back" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or structure must have a particular orientation, is constructed and operated in a particular orientation, therefore, it can not be understood as the limitation of the utility model.

[0047] Example 1:

[0048] As Figure 1 And Figure 2As shown, a tractor electric drive system includes a front steering drive axle assembly 1, a rear drive axle assembly 2, a drive gearbox assembly 3, a drive motor 4, a first shift motor 5, and a second shift motor 6. The drive gearbox assembly 3 selectively outputs two gears of power to the front steering drive axle assembly 1 and outputs one gear of power to the rear drive axle assembly 2. The first shift motor 5 is used to switch the drive gears of the front steering drive axle assembly 1, and the second shift motor 6 is used to control the engagement or disengagement of the rear drive axle assembly 2 and the drive gearbox assembly 3. The drive gearbox assembly 3 includes a four-wheel drive clutch 7, which is used to control the engagement or disengagement of the front steering drive axle assembly 1 and the drive gearbox assembly 3.

[0049] like Figure 3 As shown, in this embodiment, the walking gearbox assembly 3 includes a first shaft 301, a second shaft 302, a third shaft 303, and a front output shaft 304; it also includes an input gear 305 disposed on the first shaft 301, the first shaft 301 being connected to the walking drive motor 4; it also includes a first gear drive gear 307, a first shifting mechanism 309, a second gear drive gear 310, and a third gear drive gear 306 sequentially disposed on the second shaft 302; and a first gear driven gear 308 and a front drive gear sequentially disposed on the third shaft 303. 312, second-gear driven gear 311, third-gear driven gear 315; the rear end of the third shaft 303 is connected to the rear drive axle assembly 2, and a second shifting mechanism 314 connected to the second shifting motor 6 is provided on the third shaft 303. The second shifting mechanism 314 selectively engages or disengages from the third-gear driven gear 315; a front drive driven gear 313 is provided on the front output shaft 304, and a four-wheel drive clutch 7 is provided on the front output shaft 304 to control the engagement or disengagement of the front drive driven gear 313 and the front output shaft 304.

[0050] like Figure 3 As shown, in this embodiment, the first gear drive gear 307 and the first gear driven gear 308 cooperate, the second gear drive gear and the second gear driven gear cooperate, and the input gear and the third gear driven gear cooperate, realizing 30 gears of movement.

[0051] like Figure 3 As shown, in this embodiment, the first gear drive gear 307 and the second gear drive gear are loosely mounted on the second shaft 302, the front drive drive gear 312, the first gear driven gear 308 and the second gear driven gear are fixedly mounted on the third shaft 303, the front drive driven gear 313 is loosely mounted on the front output shaft 304, and the first shifting mechanism is fixedly mounted on the second shaft 302.

[0052] The embodiment also includes a variable speed pump assembly 8 for driving the four-wheel drive clutch 7, the variable speed pump assembly 8 including a variable speed pump 801, a variable speed pump driving motor 802 for driving the variable speed pump 801, and a solenoid valve 803 for controlling the oil passage of the four-wheel drive clutch 7. The solenoid valve 803 is connected to one end of the variable speed pump 801 and to the other end of the four-wheel drive clutch 7.

[0053] As shown in Figure 3 In the embodiment, the first shaft 301, the second shaft 302, and the third shaft 303 are arranged in parallel.

[0054] As shown in Figure 1 and Figure 3 In the embodiment, the first gear shifting motor 5, the second gear shifting motor 6, and the walking driving motor 4 are arranged outside the housing of the walking transmission assembly 3.

[0055] As shown in Figure 1 and Figure 2 The embodiment also includes a front transmission shaft 9 and a rear transmission shaft 10, both of which are universal shaft structures. One end of the front transmission shaft 9 is connected to the front output shaft 304, and the other end is connected to the front drive axle assembly 1. One end of the rear transmission shaft 10 is connected to the third shaft 303, and the other end is connected to the rear drive axle assembly 2.

[0056] As shown in Figure 3 The power transmission principle of the embodiment is as follows:

[0057] When starting or at low speed, one-gear driving is adopted, and the first gear shifting motor 5 drives the first gear shifting mechanism 309 to be located at the left position. The transmission route is: the walking driving motor 4, the first shaft 301, the input gear 305, the three-gear driving gear 306, the second shaft 302, the one-gear driving gear 307, the one-gear driven gear 308, and the third shaft 303. After that, the power is divided into two parts. The first part is directly output from the third shaft 303 to the rear transmission shaft 10, and the other part is transmitted through the front drive driving gear 312, the front drive driven gear 313, the front output shaft 304, the front transmission shaft 9, and the front drive axle assembly, realizing four-wheel drive of the front and rear wheels.

[0058] When the speed is in the middle region, two-gear driving is adopted, and the first gear shifting motor 5 drives the first gear shifting mechanism 309 to be located at the right position. The two-gear transmission path is similar to that of one-gear.

[0059] When the speed is in the high speed region, the first shift motor 5 drives the first shift mechanism 309 to be in the neutral position, and the three-gear transmission is adopted, at this time the second shift mechanism 314 is engaged, and the transmission route is: the walking driving motor 4, the first shaft 301, the input gear 305, the three-gear driving gear 306, the three-gear driven gear 315, the third shaft 303, the rear transmission shaft 10, and the rear drive axle assembly 2.

[0060] The control method of the tractor electric driving walking system comprises the following steps:

[0061] Step S1: The whole machine is started, the first shift motor 5 is controlled to switch the gear to one gear, and the four-wheel drive clutch 7 is controlled to be engaged; at this time, the one-gear four-wheel drive mode driving operation mode is adopted. The transmission route is: the walking driving motor 4, the first shaft 301, the input gear 305, the three-gear driving gear 306, the second shaft 302, the one-gear driving gear 307, the one-gear driven gear 308, and the third shaft 303. After that, the power is divided into two parts, one part is directly output to the rear transmission shaft 10 through the third shaft 303, and the other part is output to the front drive axle assembly through the front drive driving gear 312, the front drive driven gear 313, the front output shaft 304, the front transmission shaft 9.

[0062] Step S2: The vehicle speed is acquired in real time, when the vehicle speed is less than the first threshold value V1, the state of step S1 is maintained, that is, the driving mode and the gear state of step S1 are maintained, that is, the one-gear four-wheel drive mode is maintained; when the first threshold value V 1≤ Vehicle speed < The second threshold value V2, enter step S3; when the second threshold value V 2< Vehicle speed, enter step 4.

[0063] Step S3: The first shift motor 5 is controlled to switch the gear to two gears, the four-wheel drive clutch 7 is controlled to be engaged, and the step S2 is returned; at this time, the two-gear four-wheel drive mode driving operation mode is adopted.

[0064] Step S4: The second shift motor 6 is controlled to engage the three gears, the electromagnetic valve 803 controls the four-wheel drive clutch 7 to be disconnected, and the step S2 is returned. At this time, the three-gear rear drive mode is adopted, and the power transmission path is: the walking driving motor 4, the first shaft 301, the input gear 305, the three-gear driving gear 306, the three-gear driven gear 315, the second shift mechanism 314, the third shaft 303, the rear transmission shaft 10, and the rear drive axle assembly 2. At this time, the four-wheel drive clutch 7 is disconnected, the one-gear shift mechanism is in the neutral position, and the front axle has no power output. The three-gear rear drive mode is adopted, and the low-power output can reduce the energy consumption.

[0065] In this embodiment, the first threshold value V1 is 15km / h, and the second threshold value V2 is 23km / h. The two speed threshold values constitute the low speed, medium speed and high speed regions corresponding to the tractor.

[0066] As Figure 4 shown in the embodiment, the output power in step S1 is greater than that in step S3, and the output power in step S3 is greater than that in step S4. As the speed increases, the acceleration demand of the tractor decreases, and the output power can be gradually reduced to reduce energy consumption. Specifically, in step S1, when the starting speed is lower than 10 km / h, the walking driving motor outputs the full-load traction power Pmax and adopts a one-gear four-wheel drive mode to obtain better acceleration performance; in step 2, when the vehicle runs between the first threshold V1 and the second threshold V2, the traction power of the walking driving motor is gradually reduced; and in step S4, the three-gear rear-wheel drive mode is adopted, at this time, the speed is high, the acceleration demand is weakened, and low-power output can be adopted to reduce energy consumption.

[0067] As Figure 3 shown in the embodiment, the vehicle speed in step S2 is calculated by acquiring the speed signal of the gear in the walking transmission assembly 3. Specifically, in the embodiment, a speed sensor 11 is arranged on the outer edge of the first driven gear 308, and is installed on the edge of the transmission assembly, facilitating installation and disassembly. The real-time speed signal is calculated by the speed sensor 11 according to the transmission ratio, and the structure is simple and the cost is low.

[0068] As Figure 1 shown in the embodiment, the control system further includes an accelerator pedal 12, a VCU vehicle control unit 13, an MCU driving motor controller 14, a first TCU controller 15, a second TCU controller 16, and the VCU vehicle control unit 13 is electrically connected with the accelerator pedal 12, the speed sensor 11, the MCU driving motor controller 14, the first TCU controller 15, the second TCU controller 16, the transmission pump 801 and the electromagnetic valve 803.

[0069] In the embodiment, the VCU vehicle control unit 13 controls the speed of the transmission pump driving motor 802, and the VCU vehicle control unit 13 controls the on-off of the oil way of the electromagnetic valve 803 to realize the engagement or separation of the four-wheel drive clutch 7.

[0070] In step S1 of the embodiment, the VCU vehicle control unit 13 acquires the signals of the accelerator pedal 12 and the speed sensor 11 and then outputs instructions to control the MCU driving motor controller 14 to start the driving motor, control the first TCU controller 15 to drive the first shift motor 5 to engage the first shift mechanism 309 with the first gear, and control the VCU vehicle control unit 13 to control the transmission pump driving motor 802 and the electromagnetic valve 803 to engage the four-wheel drive clutch 7, so as to enter the one-gear four-wheel drive mode.

[0071] In step S3 of this embodiment, the VCU vehicle control unit 13 acquires the accelerator pedal 12 signal and the speed sensor 11 signal, and then outputs an instruction to control the first TCU controller 15 to drive the first shift motor 5 to drive the first shift mechanism 309 to engage the second gear, and the VCU vehicle control unit 13 controls the transmission pump drive motor 802 and the electromagnetic valve 803 to make the four-wheel drive clutch 7 engage, entering the second gear four-wheel drive mode;

[0072] In step S4 of this embodiment, the VCU vehicle control unit 13 issues an instruction to control the first shift motor 5 to control the first shift mechanism 309 to be in the neutral position, i.e. the neutral position, to control the electromagnetic valve 803 to achieve the separation of the four-wheel drive clutch 7, and to control the separation of the front steering drive axle assembly 1 and the transmission assembly 3. In this step, the front output shaft 304 and the front drive driven gear 313 are power disconnected, and the power output to the front transmission shaft 9 is interrupted.

Claims

1. A tractor electric drive travel system, characterized in that The front steering drive axle assembly (1), the rear drive axle assembly (2), the travel gearbox assembly (3), the travel drive motor (4), the first gear shifting motor (5) and the second gear shifting motor (6) are included; the travel gearbox assembly (3) selectively outputs power of two gears to the front steering drive axle assembly (1), and the travel gearbox assembly (3) outputs power of one gear to the rear drive axle assembly (2); the first gear shifting motor (5) is used for switching the drive gear of the front steering drive axle assembly (1); the second gear shifting motor (6) is used for controlling the engagement or separation of the rear drive axle assembly (2) and the travel gearbox assembly (3); the travel gearbox assembly (3) includes a four-wheel drive clutch (7), and the four-wheel drive clutch (7) is used for controlling the engagement or separation of the front steering drive axle assembly (1) and the travel gearbox assembly (3).

2. The electrically driven walking system of a tractor according to claim 1, characterized in that: The travel gearbox assembly (3) includes a first shaft (301), a second shaft (302), a third shaft (303) and a front output shaft (304); further comprising an input gear (305) arranged on the first shaft (301), and the first shaft (301) is connected with the travel drive motor (4); further comprising a one-gear driving gear (307), a first gear shifting mechanism (309), a two-gear driving gear (310) and a three-gear driving gear (306) arranged on the second shaft (302) in sequence; further comprising a one-gear driven gear (308), a front drive driving gear (312), a two-gear driven gear (311) and a three-gear driven gear (315) arranged on the third shaft (303) in sequence; the rear end of the third shaft (303) is connected with the rear drive axle assembly (2), and the second gear shifting mechanism (314) connected with the second gear shifting motor (6) is arranged on the third shaft (303); the second gear shifting mechanism (314) selectively engages or separates from the three-gear driven gear (315); the front output shaft (304) is provided with a front drive driven gear (313), and the four-wheel drive clutch (7) is arranged on the front output shaft (304) for controlling the engagement or separation of the front drive driven gear (313) and the front output shaft (304).

3. A tractor electric drive walking system according to claim 2, characterized in that: Further comprising a variable speed pump assembly (8) for driving the four-wheel drive clutch (7), and the variable speed pump assembly (8) includes a variable speed pump (801), a variable speed pump driving motor (802) and an electromagnetic valve (803); the variable speed pump driving motor (802) is used for driving the variable speed pump (801), and the electromagnetic valve (803) is used for controlling the oil circuit of the four-wheel drive clutch (7).

4. The electrically driven walking system of a tractor according to claim 2, characterized in that: The first shaft (301), the second shaft (302) and the third shaft (303) are arranged in parallel.

5. The electrically driven walking system of the tractor according to claim 1, characterized in that: The first gear shifting motor (5), the second gear shifting motor (6) and the travel drive motor (4) are arranged outside the housing of the travel gearbox assembly (3).

6. A tractor electric drive walking system according to claim 2, characterized in that Also included are a front transmission shaft (9) and a rear transmission shaft (10), both of which are universal shaft structures, one end of the front transmission shaft (9) is connected with the front output shaft (304) and the other end is connected with the front steering drive axle assembly (1), one end of the rear transmission shaft (10) is connected with the third shaft (303) and the other end is connected with the rear drive axle assembly (2).

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