CN217672121U - Electric tractor - Google Patents

Abstract

The utility model relates to a tractor field discloses an electric tractor, and this electric tractor's a steering system is including turning to operating mechanism (5), and electric drive system is connected to including installing power battery package (6), the electricity that corresponds to the part of front axle (2) of frame (1) and walking motor (7) and operation motor (8) and the transmission of this power battery package (6) to rear axle transmission shaft (10) between walking motor (7) and rear axle (3), walking motor (7) are located turn to the below of operating mechanism (5), operation motor (8) are installed to rear axle housing (31) and are connected to the operation power transmission subassembly of locating this rear axle housing (31) at least partially on the rear axle housing (31). This electric tractor makes the load distribution on the frame more even, and different parts and system integration, compactly arrange, are convenient for make the tractor miniaturization, can match well and be adapted to the requirement of tractor electrodynamic technical development.

Description

Electric tractor

Technical Field

The utility model relates to a tractor specifically relates to an electric tractor.

Background

A tractor is one of the indispensable working machines in agricultural production. The existing tractor industry has the problems of excess productivity, serious homogenization and the like, and the traditional fuel oil tractor can generate a large amount of harmful gas in the using process and depends on the consumption of non-renewable energy sources. With the urgent need of agricultural production environments such as facility agriculture, ecological agriculture, courtyard agriculture and the like for zero-emission, pollution-free and low-noise green power agricultural machines, electric tractors are in the process of being transported, and the electromotion of the tractors is an important direction for the development of technical innovation and environment-friendly agriculture.

Most of existing electric tractors are improved based on a traditional fuel oil tractor, the arrangement of the whole tractor basically adopts the arrangement form of the traditional fuel oil tractor, the main change is that an interface used for connecting an engine is changed into a motor interface, and the motor replaces the engine to be used as a walking and working power source so as to realize walking and working functions. Therefore, the existing electric tractor has the defects of insufficient matching and adaptability in the aspects of component composition, arrangement and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the electric tractor that prior art exists and forming and arranging the not enough problem of aspect matching nature and adaptability at the part, provide an electric tractor, this electric tractor suitably sets up the part according to motor drive's characteristic and constitutes and the arrangement mode to make load distribution and power transmission route more reasonable, make different system integration, arrange compactly, the tractor of being convenient for is miniaturized, has higher matching nature and adaptability to tractor electromotion.

In order to achieve the above object, an aspect of the present invention provides an electric tractor, including a frame, a front axle and a rear axle connected to the frame at an interval, a steering system operatively connected to the front axle in a transmission manner, and an electric drive system supported on the frame and in a transmission manner connected to the front axle and the rear axle, wherein the steering system includes a steering gear and a steering mechanism connected to the steering gear, the electric drive system includes a power battery pack mounted to a portion of the frame corresponding to the front axle, a traveling motor and an operating motor electrically connected to the power battery pack, and a rear axle transmission shaft drivingly connected to the traveling motor and the rear axle between the rear axles, the traveling motor is located below the steering mechanism, and the operating motor is mounted to a rear axle housing of the rear axle and connected to an operating power input shaft of an operating power transmission assembly at least partially disposed in the rear axle housing.

Preferably, the electric drive system further comprises a motor controller and a charging power distribution device, wherein the motor controller and the charging power distribution device are respectively connected to two sides of the frame and located between the front wheel and the rear wheel, the motor controller is in signal connection with the walking motor and/or the operation motor, and the charging power distribution device is provided with a charging port used for charging the power battery pack.

Preferably, the electric drive system further comprises a transfer case mounted to a rear end of the travel motor, the transfer case having a first output extending rearwardly and a second output extending forwardly, the rear axle drive shaft being connected to the first output, the second output being drivingly connected to the front axle by a front axle drive shaft.

Preferably, the work power transmission assembly is integrally provided with a PTO clutch located within the rear axle housing.

Preferably, the work power transmission assembly includes the work power input shaft connected to the power output end of the work motor, a work power output shaft, and an intermediate shaft connected between the work power input shaft and the work power output shaft through gear transmission, and the PTO clutch is provided on the intermediate shaft so as to be switchable by the PTO clutch such that the work power output shaft selectively receives the power input by the work power input shaft.

Preferably, the working power input shaft is disposed near a top wall of the rear axle housing, on which a hydraulic speed reducer having a hydraulic power output shaft connected to the working power input shaft through a gear transmission and a hydraulic pump connected to the hydraulic power output shaft are mounted.

Through the technical scheme, the electric tractor of the utility model independently drives the walking and the operation by the walking motor and the operation motor respectively, thereby controlling the walking and the operation process by utilizing the stepless speed change characteristic of the motor without arranging a complex speed change transmission device; through make power battery package, walking motor and install the rear axle of operation motor and arrange in proper order backward on the frame in the past, can be so that the load distribution on this frame is more even, different parts and system integration, arrange compactly, walking and operation power transmission route are reasonable, and each part can not occupy the installation space additionally, are convenient for make the tractor miniaturized, can match well and be adapted to the requirement of tractor electrodynamic technology development.

Drawings

Fig. 1 is a schematic perspective view of an electric tractor according to a preferred embodiment of the present invention;

FIG. 2 is a right side elevational view of the electric tractor of FIG. 1 with portions removed;

FIG. 3 is a left side elevational view of the electric tractor of FIG. 1 with portions removed;

fig. 4 is a bottom view of the electric tractor of fig. 1;

FIG. 5 is a schematic view of the drive and transmission arrangement of the electric tractor of FIG. 1;

FIG. 6 is a schematic perspective view of the transfer case of the electric tractor of FIG. 1;

FIG. 7 is a schematic structural view of the transfer case of FIG. 6 with the transfer case housing removed;

FIG. 8 is a schematic structural view of the transfer control assembly of the transfer case of FIG. 7 disassembled.

Description of the reference numerals

1-a vehicle frame; 2-a front axle; 3-rear axle; 31-a rear axle housing; 4-a diverter; 5-a steering control mechanism; 51-a steering wheel; 52-a steering column; 6-power battery pack; 7-a walking motor; 8-a working motor; 9-a transfer case; 91-transfer case housing; 92-an input shaft; 92 a-input shaft gear; 93-a first output shaft; 93 a-a drive gear; 93 b-driven gear; 94-an idler shaft; 94 a-an idler; 95-a second output shaft; 951-sliding sleeve external spline; 952-duplicate gear; 952 a-a first gear portion; 952 b-a second gear portion; 953-sliding sleeve; 96-transfer gear; 10-rear axle drive shaft; 11-front axle drive shaft; 12-a heat sink; 13-a hood; 14-a motor controller; 141-a walking motor controller; 142-a work motor controller; 15-charging power distribution devices; 16-a hydraulic retarder; 17-a hydraulic pump; 18-a hydraulic lift cylinder; 19-three point suspension; 20-an instrument mask; 21-front wheel; 22-a rear wheel; 23-a mud-guard tile; 24-an adjustment element; 25-a seat; 26-a combination handle; 27-a brake pedal; 28-gantry.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.

In the present invention, unless otherwise specified, terms of orientation such as "front", "rear", "upper", "lower", and the like used herein are understood with reference to the conventional direction of the vehicle, and "inner" and "outer" refer to the inner and outer with respect to the outline of each member itself.

Referring to fig. 1 to 5, an electric tractor according to a preferred embodiment of the present invention includes: a running system having a frame 1, a front axle 2 and a rear axle 3 connected to the frame 1 at a distance from each other, wheels (i.e., a front wheel 21 and a rear wheel 22) connected to the front axle 2 and the rear axle 3, respectively, and the like; a steering system operatively drivingly connected to front axle 2 to be operable to turn front wheels 21 connected to front axle 2 to effect steering; a transmission system, which comprises a transmission shaft (such as a front axle transmission shaft 11 and a rear axle transmission shaft 10) and the like for transmitting the torque output by the walking motor 7 to the rear axle 3 (and/or the front axle 2); a brake system that can be manipulated to generate a braking force, such as by a brake pedal 27, to effect deceleration or stopping. In addition, the electric tractor is provided with a power battery pack 6 mounted to the vehicle frame 1, and a traveling motor 7 and a working motor 8 electrically connected to the power battery pack 6, the traveling motor 7 and the working motor 8 being capable of obtaining electric power from the power battery pack 6 and outputting power for driving traveling and working, respectively, as power sources. In order to facilitate a better understanding of the interrelationship of the various parts, in the following description, the power source including the power battery pack 6, the travel motor 7 and the work motor 8, and the above-described transmission system will be described as being part of an electric drive system to more accurately express the driving and transmission characteristics of the electric tractor. In addition, the electric tractor may be provided with other accessories such as a meter and a lighting device as necessary.

Specifically, the frame 1 as the main load-bearing member of the electric tractor of the present invention may have a pair of longitudinal beams extending parallel to each other and a plurality of cross beams connected between the pair of longitudinal beams, and the front axle 2, the rear axle 3, the steering system, and the related components of the electric drive system may all be mounted to the frame 1 so as to be maintained in relatively correct positions. Generally, a steering system includes a steering gear 4 and a steering gear 5 connected to the steering gear 4, and the steering gear 5 may include a steering column 52 extending obliquely and a steering wheel 51 connected to an upper end of the steering column 52, and an operator may rotate the front wheels 21 by rotating the steering wheel 51 to perform steering driving.

As described above, the electric drive system includes the power battery pack 6, the traveling motor 7 and the working motor 8, etc., which are electrically connected to the power battery pack 6, wherein the power battery pack 6 is mounted to the vehicle frame 1 at a position corresponding to the front axle 2, i.e., the power battery pack 6 is positioned above the front axle 2, whereby its weight is exerted on the front axle 2 mainly through the vehicle frame 1. Under the situation of front axle 2 as steering axle, the utility model discloses an electric tractor is at least as the transaxle with rear axle 3, for this reason, the transmission is connected with rear axle transmission shaft 10 between walking motor 7 and rear axle 3, and from this, the power that walking motor 7 produced can transmit to this rear axle 4 to drive rear wheel 22 and rotate, realize the walking function.

The utility model discloses an electric tractor utilizes walking motor 7 and operation motor 8 independently to drive walking and operation respectively to can utilize motor infinitely variable's characteristic control walking and operation process, and need not to set up complicated variable speed transmission. In this case, the electric tractor has a great difference from a conventional fuel oil tractor in terms of component composition, and the arrangement of components needs to be arranged reasonably. The power battery pack 6 occupies the installation space of the frame 1 corresponding to the front axle 2, and the walking motor 7 is one of the main power sources, and belongs to a part with relatively large volume and weight in the electric tractor. The utility model discloses an among the electric tractor, walking motor 7 arranges in the below that turns to operating mechanism 5 to can fix to frame 1 through the installing support, make full use of turns to the narrow and small space of operating mechanism 5 below from this, and be convenient for utilize the transmission shaft of appropriate length with power transmission to rear axle 3 (with front axle 2). Wherein, a mounting bracket can be fixed on the inner side of the longitudinal beams of the frame 1, so that the walking motor 7 occupies the space between the longitudinal beams in the height direction, and is arranged so that the lowest point of the walking motor 7 is lower than the lowest point of the frame 1, which has high space utilization rate. The weight of the traveling motor 7 is applied to the middle section of the vehicle frame 1 between the front axle 2 and the rear axle 3.

Generally, the three-point hitch 19 and other working devices are generally disposed at the rear side of the tractor and can be powered by the working motor 8 independently of the traveling motor 7, and therefore, the working motor 8 can be disposed at a position appropriately close to the rear side of the tractor to avoid complication of the power transmission path. The utility model discloses in, on operation motor 8 (if through fasteners such as bolt) installs the rear-axle housing 31 to rear axle 3, this operation motor 8's power take off end is connected with the operation power transmission subassembly that is used for transmitting power to the operation device, and this operation power transmission subassembly is located in rear-axle housing 31 at least partially to receive the power that this operation motor 8 produced through the operation power input shaft that is connected to operation motor 8. Thus, the electric tractor integrally provides a power take-off (PTO) on the rear axle 3 and locates at least part of the components within the rear axle housing 31, so that the working power transmission assembly and the running system are integrated and compactly arranged, with the weight thereof being mainly applied to the rear axle 3 through the vehicle frame 1.

Therefore, the utility model discloses an electric tractor arranges in proper order on frame 1 through making power battery package 6, walking motor 7 and the rear axle 3 from the front to the back that installs operation motor 8, can be so that the load distribution on this frame 1 is more even, different parts and system integration, arrange compactly, walking and operation power transmission route are reasonable, and each part can not additionally occupy installation space, be convenient for make the tractor miniaturized, can match well and be adapted to the requirement of tractor electrodynamic technology development.

With continued reference to fig. 1 to 5, a radiator 12 may be mounted on the frame 1, and the radiator 12 may be disposed in front of the power battery pack 6, so as to exchange heat with the air flow in front during driving, thereby achieving rapid heat dissipation. The radiator 12 may be used to cool the traveling motor 7, the working motor 8, and the motor controller 14 and the charging power distribution device 15, which will be described later, and for this purpose, these components may be connected to the radiator 12 by fluid lines, so that cooling water can circulate therebetween to take away heat generated during the operation of these components, thereby preventing high-temperature damage. Specifically, a fluid passage may be formed in the radiator 12, and the fluid passage may be connected to the walking motor 7, the working motor 8 and the like through a fluid pipe to form a fluid circulation loop, and an electromagnetic pump may be provided in the fluid circulation loop to pump a heat dissipation fluid such as cooling water to circulate in the fluid circulation loop, so that the heat is dissipated to the outside through the radiator 12. Wherein the electromagnetic pump may be mounted, for example, below the radiator 12.

In order to maintain the appearance and reduce the explosion risk of the power battery pack 6 caused by external collision, etc., a hood 13 may be mounted on the frame 1, and the hood 13 covers the power battery pack 6 and the radiator 12 and may be formed with a plurality of heat dissipation holes or heat dissipation grids so that the heat of the power battery pack 6 and the radiator 12 is dissipated outwards.

At the rear end of the hood 13, a portal frame 28 may also be mounted on the frame 1, and the portal frame 28 may enhance the overall rigidity of the frame 1 and may also serve as a handrail for a driver to get on the driving seat. The steering mechanism 5 may be disposed behind the gantry 28, and includes a steering wheel 51 and a steering column 52, the steering column 52 extending obliquely rearward from the bottom up. The lower end of the steering column 52 is connected to a steering gear 4, which steering gear 4 can be connected to the front axle 2, for example by a hydraulic line transmission, so as to be able to be manipulated by the steering wheel 51 in such a way as to turn the front wheels 21 connected to the front axle 2.

Similar to a typical vehicle, a combination handle 26 mounted to the steering column 52 may be provided beneath the steering wheel 51 for controlling illumination devices such as high and low beam switches and turn signals. In addition, a display instrument covered by the instrument cover 20 may be further disposed below the steering wheel 51, including a speedometer, a motor tachometer, a battery thermometer, an electricity meter, and various indicator lights (such as a fault indicator light and a charging indicator light).

Further, in the electric tractor according to a preferred embodiment of the present invention, the electric drive system may further include a motor controller 14 and a charging power distribution device 15, and the motor controller 14 and the charging power distribution device 15 may be respectively connected to both sides of the frame 1 and located between the front and rear wheels. Specifically, in the illustrated preferred embodiment, the motor controller 14 is disposed on the left side (outside the side member) of the frame 1 between the front wheel 21 and the rear wheel 22 on the left side, and the motor controller 14 includes a traveling motor controller 141 signal-connected to the traveling motor 7 and a working motor controller 142 signal-connected to the working motor 8 so as to be able to be used for independently controlling the rotation speed and the output torque of the traveling motor 7 and the working motor 8, respectively, one of which may be disposed directly above the other to fully utilize the longitudinal space outside the frame 1; the charging power distribution device 15 is disposed on the right side (outside of the side member) of the vehicle frame 1 between the front wheel 21 and the rear wheel 22 on the right side, and the traveling motor controller 141 and the working motor controller 142 may be connected to the power battery pack 6 through the charging power distribution device 15, respectively. This distribution device 15 that charges is equipped with the direct current and charges mouthful and exchange the mouth that charges, realizes high multiplying power direct current from this easily and fills soon, effectively shortens the charge time, promotes user experience. In addition, this distribution device 15 that charges can set up to detect the electric quantity of battery (not mark) and communicate with it when the tractor is placed for a long time to charge the battery through power battery package 6 by oneself, avoid insufficient voltage problem.

In order to adapt to various walking operating modes better or go with the four-wheel drive mode, the utility model discloses an electric tractor can set up transfer case 9 in the transmission path between walking motor 7 and axle to can make the power that walking motor 7 produced only export to rear axle 3 or export to front axle 2 and rear axle 3 simultaneously. Wherein, in the illustrated preferred embodiment, the transfer case 9 is mounted to the rear end of the walking motor 7 to receive the power generated by the walking motor 7 by being connected with the power output end of the walking motor 7, and by this arrangement, the compact arrangement of the transmission components can be realized with a small space occupation. Specifically, the transfer case 9 may have a first output end extending backward and a second output end extending forward, wherein the first output end is connected with a rear axle transmission shaft 10, and at least a part of the power generated by the traveling motor 7 is transmitted to the rear axle 3 through the rear axle transmission shaft 10; a front axle drive shaft 11 is connected to the second output, and the other end of the front axle drive shaft 11 is connected to the front axle 2 to allow the front axle 2 to receive a portion of the power generated by the travel motor 7.

Wherein, transfer case 9 can set up to be handled as required for distributing the power that walking motor 7 produced between front axle 2 and rear axle 3, from this, when walking under the field of different humidity, the road surface of going of different slopes etc. operating mode, the utility model discloses an electric tractor can make the wheel obtain different rotation torque through controlling transfer case 9 to the walking operating mode before better fitting. For example, when walking in a muddy field, the transfer case 9 can be switched to the four-wheel drive mode, and the walking motor 7 simultaneously drives the front wheels 21 and the rear wheels 22 to rotate, thereby avoiding problems such as difficulty in walking due to wheel slip and the like.

Fig. 6 to 8 are schematic structural views of a transfer case used in a preferred embodiment of the present invention. Wherein the transfer case includes a transfer case housing 91, and an input shaft 92, a first output shaft 93, an idler shaft 94, and a second output shaft 95 rotatably mounted to the transfer case housing 91, respectively. Wherein, the transfer case 91 may be formed in a split structure and has a front case portion and a rear case portion hermetically connected to an open end of the front case portion, which may be positioned by a positioning pin and detachably connected to each other by a plurality of bolts, so that the respective shafts and the gears thereon are mounted, and damage of the gears due to foreign matter such as dust is avoided or reduced. Meanwhile, lubricating oil can be contained in the transfer case shell 91 so as to lubricate meshed gears and ensure transmission efficiency.

The input shaft 92, first output shaft 93, idler shaft 94 and second output shaft 95 may be rotatably mounted to the front and rear side walls of the transfer case housing 91 by bearings (not labeled), respectively, so as to be free to rotate relative to the transfer case housing 91. Wherein, the part of the input shaft 92 extending out of the transfer case shell 91 can be formed with external splines so as to be in transmission connection with a power output end of the walking motor 7 for receiving power from the walking motor. The input shaft 92 is fixedly provided with an input shaft gear 92a, for example, the input shaft 92 and the input shaft gear 92a may be integrally formed to be a gear shaft, or the input shaft gear 92a may be fixed to the input shaft 92 in the circumferential direction by splines. Thus, the "fixed" relationship of the gear and shaft described herein and below means that the two are circumferentially relatively fixed so as to be capable of being driven into synchronous rotation.

The first output shaft 93 is fixedly provided with a driving gear 93a and a driven gear 93b, and the driving gear 93a and the driven gear 93b can be properly spaced in the axial direction to prevent unnecessary movement interference during meshing with other gears. The driving gear 93a is engaged with an input shaft gear 92a of the input shaft 92, and the driven gear 93b is engaged with an idler gear 94a fixed to an idler shaft 94. Thus, the power from the traveling motor 7 can be input through the input shaft 92, output through the first input shaft 93, and transmitted to the idler shaft 94.

Further, a sliding sleeve external spline 951 is fixedly arranged on the second output shaft 95, and a duplicate gear 952 is rotatably sleeved on the second output shaft 95, wherein the duplicate gear 952 can rotate relative to the second output shaft 95 (for example, is mounted on the second output shaft 95 through a deep groove ball bearing), and has a first gear portion 952a and a second gear portion 952b. Wherein the first gear portion 952a is intermeshed with the idle gear 94a to receive power transmitted by the idle gear 94 a; the second gear unit 952b is axially offset from the first gear unit 952 a. The sliding sleeve outer spline 951 is provided with a sliding sleeve 953 engaged therewith, the sliding sleeve 953 is engaged with the sliding sleeve outer spline 951 through internal teeth so as to be capable of synchronous rotation, and the sliding sleeve 953 can be manipulated to slide in the axial direction so as to be selectively engaged with the second gear unit 952b of the double gear 952.

Therefore, the traveling motor 7 can drive the input shaft 92 to rotate, so as to drive the first output shaft 93 to rotate and output power to the rear axle transmission shaft 10 connected with the first output shaft. At the same time, the driven gear 93b of the first output shaft 93 drives the idle gear 94a engaged therewith to rotate, thereby transmitting power to the dual gear 952. At this time, if the sliding sleeve 953 is in a position not engaged with the second gear portion 952b of the double gear 952, the double gear 952 idles on the second output shaft 95, so that the electric tractor can perform a two-drive (rear-drive) running mode by the power output from the first output shaft 93; when the sliding sleeve 953 slides to a position where it is engaged with the second gear portion 952b of the double gear 952, a part of the power input from the input shaft 92 is transmitted to the second output shaft 95 and the front axle transmission shaft 11 connected thereto through the input shaft gear 92a, the driving gear 93a, the driven gear 93b, the idle gear 94a, the first gear portion 952a of the double gear 952, the second gear portion 952b of the double gear, the sliding sleeve 953, and the sliding sleeve external spline 951 in this order, so that the electric tractor can perform the four-wheel drive mode. Therefore, the transfer case can timely execute the transfer function by controlling the sliding sleeve 953, so that the power from the walking motor 7 is distributed to the front axle 2 and/or the rear axle 3 according to requirements to adapt to different running conditions.

In the transfer case, the first output shaft 93 and the second output shaft 95 can be rotated in the same direction by an idler pulley 94a provided between the first output shaft 93 and the second output shaft 95 for transmission, thereby conveniently connecting the respective output ends thereof to the front axle 2 and the rear axle 3 in a corresponding transmission manner. Control components such as the sliding sleeve external spline 951, the sliding sleeve 953 and the duplicate gear 952 for transfer control are arranged on the second output shaft 95, so that the second output shaft 95 and the first output shaft 93 are arranged in a staggered mode, the size of the transfer case in the front-back direction of the electric tractor can be allowed to be small, the occupied space in the longitudinal direction is reduced, and the transfer case can be directly mounted on the traveling motor 7 conveniently.

The number of teeth of the input shaft gear 92a may be less than that of the driving gear 93a, so that the transmission ratio between the input shaft gear 92a and the driving gear 93a is greater than 1, the rotation speed of the first output shaft 93 can be less than the input rotation speed of the input shaft 92, and a speed reduction function is achieved. From this, need not in the utility model discloses an electric tractor sets up the gearbox among the conventional art, therefore can conveniently install on walking motor 7. Accordingly, the transfer operating mechanism 96 can also be disposed in a position close to the driver more conveniently, while the transmission shafts drivingly connected to the front axle 2 and the rear axle 3 need not take the form of a plurality of combinations or intermediate supports, thus facilitating lightweight design of the components.

In addition, the driven gear 93b on the first output shaft 93 and the first gear portion 952a of the double gear 952 on the second output shaft 95 may have the same number of teeth, and thus have the same rotation speed since both are simultaneously engaged with the idle gear 94a on the idle gear shaft 94. In this case, the first output shaft 93 and the second output shaft 95 may have the same rotation direction and the same rotation speed, so that the rotation speeds of the front wheel 21 and the rear wheel 22 may be the same without increasing or decreasing in the subsequent transmission process, thereby avoiding the problems of complicated structure of the transmission system, and the like.

In the illustrated preferred embodiment, the input shaft gear 92a, the driving gear 93a, the driven gear 93b and the idle gear 94a are helical gears, respectively, thereby having advantages of smooth transmission, less shock, vibration and noise, and being suitable for transmitting large torque. In other embodiments, the gears may also adopt other forms of gears, such as straight toothed spur gears, etc., and can also realize the transmission function, and have the functions of speed reduction and transmission at the same rotating speed through proper tooth number setting.

The above-mentioned input shaft 92, first output shaft 93, idler shaft 94 and second output shaft 95 are installed so that their respective rotational axes are parallel to each other due to the spur gear mesh transmission, whereby the first output shaft 93 is made to project in the longitudinal direction from one side of the transfer case housing 91, and the second output shaft 95 is made to project in the longitudinal direction from the other side of the transfer case housing 91, thereby connecting the rear axle transmission shaft 10 and the front axle transmission shaft 11, respectively. In order to reduce the center-to-center distance between the different shafts, in the illustrated preferred embodiment, the angle between the vertical line connecting the respective rotational axes of the first output shaft 93 and the idler shaft 94 and the vertical line connecting the respective rotational axes of the idler shaft 94 and the second output shaft 95 is not more than 90 °, whereby an excessive dimension of the transfer case in the height direction can be avoided, facilitating a compact arrangement thereof in the vehicle.

As aforementioned, the utility model discloses an operation motor 8 is installed to the rear-axle housing 31 of rear axle 3 on, and operation power transmission assembly locates at least partially in this rear-axle housing 31 to be used for transmitting power to the operation device who is connected to the automobile body rear. Wherein the work power transmission assembly may be integrally provided with a PTO clutch in the rear axle housing 31 to enable switching of the engagement state of (the work power output shaft of) the power take-off and the work motor 8 by the PTO clutch.

Specifically, a final drive may be provided in the rear axle housing 31 to decelerate the power transmitted from the traveling motor 7 by the rear propeller shaft 10 to the rear wheels 22. The working power transmission assembly may include a working power input shaft, an intermediate shaft and a working power output shaft which are in turn drivingly connected by gears, these shafts being rotatably supported by bearings on the housing wall and/or support ribs of the rear axle housing 31. Wherein the working power input shaft extends through the front wall of the rear axle housing 31 and is connected directly or indirectly to the working motor 8 at an end outside the rear axle housing 31.

The intermediate shaft may be provided to extend within the mounting cavity of the rear axle housing 31 and be provided with a PTO clutch, whereby when the PTO clutch is in an engaged state, torque from the work motor 8 input by the work power input shaft can be transmitted through the intermediate shaft and drive the work device to operate; conversely, the torque from the working motor 8 input by the working power input shaft cannot be transmitted to the working device.

The working power output shaft extends through the rear side wall of the rear axle housing 31, and the end portion of the working power output shaft extending out of the mounting cavity can be connected with a working device. As a result, the torque input from the working power input shaft can be transmitted to the working power output shaft via the intermediate shaft and output to the working device connected thereto. By switching the engagement state of the PTO clutch, the power transmission connection relationship between the working device and the working motor can be connected or disconnected.

Most parts through with operation power transmission assembly arrange in rear axle housing 31's installation intracavity, the utility model discloses an electric tractor has higher integrated level. This operation power transmission assembly adopts single-gear transmission mode to the integrated PTO clutch that is used for switching operation power transmission that is provided with, therefore can avoid rear-axle housing 31 bulky, and need not to set up clutch and variable speed operating mechanism alone, has reduced the part setting, and the structure is compacter, can conveniently control its walking and operation process through the control to walking motor 7 and operation motor 8.

In an electric tractor, it is often necessary to generate hydraulic action using a hydraulic pump to drive the action of components such as the hydraulic lift cylinder 18 in the three-point hitch 19. In the electric tractor according to the preferred embodiment of the present invention, a hydraulic pump 17 is further included, which is connected to the working power input shaft through a hydraulic reducer 16, so that the working motor 8 can drive the hydraulic pump 17 to rotate while selectively driving the working device, to obtain a desired oil pressure. Specifically, the hydraulic retarder 16 may include a hydraulic power output shaft connected to the work power input shaft by gear transmission. The hydraulic power take-off shaft may be connected to a power input shaft of the hydraulic pump 17, thereby enabling driving the hydraulic pump 17 to pump pressure oil.

In the illustrated preferred embodiment, the working power input shaft is disposed near a top wall of the rear axle housing 31, whereby the hydraulic retarder 16 and the hydraulic pump 17 can be integrally mounted on the rear axle housing 31. Specifically, since the working power input shaft needs to connect the intermediate shaft and the hydraulic power output shaft at the same time through meshing gear transmission, by disposing the working power input shaft in a position close to the top wall of the rear axle housing 31, the intermediate shaft can be made to extend backward through a space above the axle shafts, and at the same time, the hydraulic speed reducer 16 can be mounted on the top wall of the rear axle housing 31. The space left above the top wall of the rear axle housing 31 not occupied by the hydraulic retarder 16 is available for mounting the hydraulic pump 17, and the hydraulic pump 17 may be fixed to the top wall of the rear axle housing 31. In order to ensure reliable transmission and avoid unnecessary space occupation, among others, the hydraulic reducer 16 may be disposed at an end of the top wall adjacent to the front side wall, while the hydraulic pump 17 is disposed at the rear side of the hydraulic reducer 16, which is advantageous for the miniaturization of the electric tractor.

The hydraulic pump 16 may be connected to the hydraulic lift cylinder 18 and/or the steering system at the rear end of the rear axle housing 31 via a hydraulic line to supply pressurized oil to the hydraulic lift cylinder 18 and/or the steering system for hydraulic lift and power steering.

A seat 25 may be mounted above the rear axle 3 and an accelerator pedal and a brake pedal 27 may be mounted on the floor in front of the seat 25. When the PTO operation mode is selected, the work motor 8 may be operated at a predetermined speed, and the accelerator pedal is operated only to control the rotation speed of the travel motor 7, thereby achieving independent control of travel and work. The predetermined speed of the work motor 8 may be set to provide two different drive speeds to the PTO as required, such as 540 rpm and 720 rpm.

The rear wheel 22 at the two ends of the rear axle 3 may be provided with a mud guard 23, and the right side of the mud guard 23 may be provided with a four-way switch, a thumb handle, a fixed speed knob, an electro-hydraulic suspension controller and other adjusting elements 24, wherein the fixed speed knob may be set to adjust the rotating speed of the walking motor 7 or the working motor 8, so as to adjust the walking speed of the electric tractor or the action speed of the working device.

The preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited thereto. The technical concept of the utility model is in the scope, can be right the utility model discloses a technical scheme carries out multiple simple variant, makes up with any suitable mode including each concrete technical characteristics. In order to avoid unnecessary repetition, the present invention does not separately describe various possible combinations. These simple variations and combinations should also be considered as disclosed in the present invention, all falling within the scope of protection of the present invention.

Claims (15)

1. An electric tractor, characterized by comprising a frame (1), a front axle (2) and a rear axle (3) connected to the frame (1) at a distance from each other, a steering system operatively drivingly connected to the front axle (2), and an electric drive system carried on the frame (1) and drivingly connected to the front axle (2) and the rear axle (3), wherein the steering system comprises a steering gear (4) and a steering mechanism (5) connected to the steering gear (4), the electric drive system comprises a power pack (6) mounted to a portion of the frame (1) corresponding to the front axle (2), a travel motor (7) and a work motor (8) electrically connected to the power pack (6), and a rear axle drive shaft (10) drivingly connected between the travel motor (7) and the rear axle (3), the travel motor (7) is located below the steering mechanism (5), and the work motor (8) is mounted to a rear axle housing (31) of the rear axle (3) and is connected at least partially to an input shaft of a power axle housing (31) of the rear axle housing (31).

2. The electric tractor according to claim 1, characterized in that the frame (1) has a pair of longitudinal beams extending parallel to each other and a plurality of cross beams connected between the pair of longitudinal beams, the power battery pack (6) being fixed to the longitudinal beams by a plurality of mounting brackets.

3. The electric tractor according to claim 2, characterized in that a radiator (12) located in front of the power battery pack (6) and a hood (13) covering the power battery pack (6) and the radiator (12) are mounted on the frame (1).

4. The electric tractor according to claim 3, characterized in that a portal frame (28) is mounted on the frame (1) at the rear end of the hood (13).

5. The electric tractor according to claim 3, characterized in that the radiator (12) has a fluid passage formed therein and is connected to at least one of the traveling motor (7) and the working motor (8) through a fluid line to form a fluid circulation circuit in which an electromagnetic pump for pumping a circulation flow of a heat dissipation fluid is provided.

6. The electric tractor according to claim 1, characterized in that the electric drive system further comprises a motor controller (14) and a charging power distribution device (15) connected to both sides of the frame (1) and located between the front and rear wheels, respectively, the motor controller (14) being signally connected to the walking motor (7) and/or the working motor (8), the charging power distribution device (15) being provided with a charging port for charging the power battery pack (6).

7. The electric tractor according to claim 1, characterized in that the electric drive system further comprises a transfer case (9) mounted to the rear end of the travel motor (7), the transfer case (9) having a first output extending rearwardly and a second output extending forwardly, the rear axle drive shaft (10) being connected to the first output, the second output being drivingly connected to the front axle (2) by a front axle drive shaft (11).

8. The electric tractor according to claim 7, characterized in that the transfer case (9) can be manipulated so that at least one of the front axle (2) and rear axle (3) selectively receives the power output by the walking motor (7) to have different walking drive modes.

9. The electric tractor according to claim 8, characterized in that the transfer case (9) includes a transfer case housing (91) and an input shaft (92), a first output shaft (93), an idler shaft (94) and a second output shaft (95) rotatably mounted to the transfer case housing (91) respectively and extending parallel to each other, wherein: the input shaft (92) is connected to a power output shaft of the walking motor (7) and is fixedly provided with an input shaft gear (92 a); a driving gear (93 a) and a driven gear (93 b) are fixedly arranged on the first output shaft (93), and the driving gear (93 a) is meshed with the input shaft gear (92 a); the idler shaft (94) is provided with an idler (94 a) which is meshed with the driven gear (93 b); and a sliding sleeve external spline (951) is fixedly arranged on the second output shaft (95) and is rotatably sleeved with a duplicate gear (952), the duplicate gear (952) is provided with a first gear part (952 a) meshed with the idle gear (94 a) and a second gear part (952 b) axially offset relative to the first gear part (952 a), and a sliding sleeve (953) which is matched with the sliding sleeve external spline (951) and can be controlled to axially slide is arranged on the sliding sleeve external spline (951) so that the sliding sleeve (953) is selectively jointed to the second gear part (952 b).

10. The electric tractor according to claim 9, characterized in that the input shaft gear (92 a) has a smaller number of teeth than the driving gear (93 a) and/or the driven gear (93 b) has a number of teeth equal to the first gear part (952 a).

11. The electric tractor according to claim 1, characterized in that the work power transmission assembly is integrally provided with a PTO clutch located within the rear axle housing (31).

12. The electric tractor according to claim 11, characterized in that the work power transmission assembly comprises the work power input shaft connected to the power output of the work motor (8), a work power output shaft, and an intermediate shaft connected between the work power input shaft and the work power output shaft by gear transmission, the PTO clutch being provided on the intermediate shaft to be switchable by the PTO clutch such that the work power output shaft selectively receives power input by the work power input shaft.

13. The electric tractor according to claim 12, characterized in that the working power input shaft is disposed close to a top wall of the rear axle housing (31) on which a hydraulic retarder (16) and a hydraulic pump (17) are mounted, the hydraulic retarder (16) having a hydraulic power output shaft connected to the working power input shaft through a gear transmission, the hydraulic pump (17) being connected to the hydraulic power output shaft.

14. The electric tractor according to claim 13, characterized in that a hydraulic lift cylinder (18) is connected to the rear end of the rear axle housing (31), the hydraulic pump (17) being connected to the hydraulic lift cylinder (18) and/or the steering system by a hydraulic line so as to be drivable by the working motor (8) to pump pressurized oil to the hydraulic lift cylinder (18) and/or the steering system.

15. The electric tractor according to claim 1, characterized in that a fender (23) is provided above the rear wheels (22) mounted at both ends of the rear axle (3), and an adjusting element (24) for adjusting the rotational speed of the traveling motor (7) and/or the working motor (8) is provided on at least one fender (23).

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