CN214216168U - Rodless aircraft tractor with four-wheel drive - Google Patents

Abstract

The four electrically driven independent 360-degree or +/-180-degree steering driving units are adopted as a power system and a steering system of a vehicle, so that the accurate control of the walking and steering actions of the tractor is realized, and the vehicle can well meet the condition of higher control accuracy requirement; meanwhile, a gap is reserved between two rear wheels of the tractor, so that tires of an aircraft landing gear can conveniently enter the center of the tractor body, the four driving wheels of the vehicle are uniformly stressed, the motor power of a single driving wheel is reduced, the heating of the motor is reduced, the service life of equipment is fully prolonged, and the safety of the tractor when the tractor pulls the aircraft is improved; the four driving units are not mechanically connected with each other, other hydraulic devices are not needed for assistance, the four driving units are directly installed on the chassis of the tractor, the structure is simple, the installation is convenient, the maintenance cost is low, the occupied space of the driving units is small, and the overall dimension of the tractor is convenient to reduce.

Description

Rodless aircraft tractor with four-wheel drive

Technical Field

The utility model belongs to the technical field of the aircraft tractor, concretely relates to rodless aircraft tractor with four wheel drive.

Background

The electronic rodless aircraft tractor (hereinafter referred to as tractor) on the existing market mostly adopts rear wheel differential drive, front wheel universal wheel structure, and when pulling the aircraft, the nose landing gear center of aircraft and tractor rear wheel central line vertical cross, the weight of aircraft landing gear is whole on the rear wheel drive center of tractor like this, like in the rodless aircraft tractor that patent number 201710113578.1 disclosed, through the atress analysis to aircraft tractor in this patent can know, this chassis structure has following several problems:

1. the rear wheel differential drive, undercarriage central line are just to the tractor rear wheel axial lead, and the atress of tractor is not good:

1) when the tractor retreats the aircraft from the gallery bridge and pushes out the atress is normal, but when pulling the aircraft, there can not be any foreign matter on tractor place ahead ground to cause collision or resistance to the wheel, otherwise because the horizontal pulling force of undercarriage to the tractor that aircraft inertia caused, probably causes tractor afterbody perk, collision damage aircraft.

2) When the tractor pulls the aircraft to move ahead, the drive tire receives the reaction force on ground, and the tractor front portion perks easily, in case ground unevenness or when having the foreign matter to the front wheel collision of tractor, the tractor front portion pops up very easily, causes the injury to the aircraft.

3) The structure can not be used for climbing and driving when the traction aircraft moves forwards, namely, the ground can not have any gradient, and the gravity point of the aircraft landing gear is very easy to exceed the axis of the rear wheel when climbing, so that the safety accident that the traction vehicle head tilts up is caused.

The structure can be used only by pushing the aircraft out by the towing vehicle in the operation of backing the aircraft from the gallery bridge to the takeoff preparation position.

2. The central line of the undercarriage is over against the central line of the rear wheel shaft of the tractor, and four wheels of the tractor are stressed and bear unevenly: the electric aircraft tractor with the structure has the advantages that the driving wheel bearing is heavy, the steering wheel bearing is small, and the side with good mechanical structure rigidity and strength performance of the electric aircraft tractor is on the side of the steering wheel, so that the side frame of the driving wheel is easier to deform, and the service lives of the side tire, the bearing and the like of the driving wheel are rapidly reduced; meanwhile, the driving motor has high power and high current, and can quickly heat, thereby having certain potential safety hazard and high vehicle maintenance cost after long-term use.

3. The rear wheel is driven by differential speed, the front wheel universal wheel (with power or without power) rotates, under the structure, when a vehicle is reversed in a forward/backward direction or in a left/right direction, due to the limitation of an eccentric structure of the universal wheel, the universal wheel rotates in the direction reversing, when the vehicle is reversed in the driving direction, deflection inevitably occurs, when the speed is too high, even a vibration phenomenon occurs, and the deflection to the specific side cannot be controlled. The phenomenon occurs already when some domestic enterprises imitate foreign products, and vehicles cannot be normally used under the condition of higher control precision requirement.

In addition, in the four-wheel independent steering device of the aircraft tractor disclosed in patent No. 201110285392.7, a hydraulic drive four-wheel independent steering device based on a tie rod principle is discussed, and the defects of the hydraulic drive four-wheel independent steering device are that the mechanical structure is complicated, the installation, the maintenance and the maintenance are inconvenient, and the occupied space of a motion unit is large, so that the overall appearance of the vehicle is large. In the four-wheel independent steering device of the aircraft tractor disclosed in patent No. 200810100025.2, the four-wheel independent steering device driven by the independent hydraulic cylinder is discussed, the hydraulic system and the control system thereof required by the four-wheel independent steering device are very complex, the maintenance workload of the user is large, and meanwhile, the overall appearance of the vehicle is large due to the large occupied space of the motion unit. Meanwhile, according to the two patents, the tractor is determined to be only a traction operation mode with a traction rod, and the use limitation is large.

For the above reasons, we need to propose a new four-wheel drive aircraft tractor with four-wheel drive and four-wheel steering.

SUMMERY OF THE UTILITY MODEL

The utility model provides a technical problem: the utility model provides a rodless aircraft tractor with four wheel drive, the utility model discloses a but four electrically driven independent 360 degrees or 180 degrees drive unit that turn to are adopted as the driving system and the steering system of vehicle, realize the tractor walking, turn to the accurate control of action, make the vehicle can be fine satisfy the higher condition of control accuracy requirement; meanwhile, a gap is reserved between two rear wheels of the tractor, so that tires of an aircraft landing gear can conveniently enter the center of the tractor body, the four driving wheels of the vehicle are uniformly stressed, the motor power of a single driving wheel is reduced, the heating of the motor is reduced, the service life of equipment is fully prolonged, and the safety of the tractor when the tractor pulls the aircraft is improved; the four driving units are not mechanically connected with each other, other hydraulic devices are not needed for assistance, the four driving units are directly installed on the chassis of the tractor, the structure is simple, the installation is convenient, the maintenance cost is low, the occupied space of the driving units is small, and the overall dimension of the tractor is convenient to reduce.

The utility model adopts the technical proposal that: the rodless aircraft tractor with four-wheel drive comprises a chassis, wherein four corners of the lower part of the chassis are respectively provided with a drive unit, each drive unit is independently arranged and is not mechanically connected with each other, each drive unit is provided with a steering motor and a walking motor which can realize the functions of walking and steering simultaneously, the rear part of the chassis is provided with a vehicle-mounted main controller, the number of the drive units corresponding to the rear part of the chassis is provided with a plurality of motor drivers, each motor driver is electrically connected with the vehicle-mounted main controller, and each motor driver is connected with the steering motor and the walking motor of the corresponding drive unit; the independent arrangement of the driving units enables a gap for mounting the wheel clasping mechanism and facilitating the tire of the undercarriage to enter the center of the vehicle body to be reserved in the middle of the chassis, and the vertical center line of the tire of the undercarriage coincides with the intersection of the diagonal connecting lines of the rotation center points of the four driving units.

The technical scheme is further limited, the angle of the shaft axis of each driving unit relative to the central line of the chassis is variable within the range of 360 degrees or +/-180 degrees, and the vehicle-mounted main controller controls the driving units through the motor driver to enable the angles of the shaft axes of the driving units relative to the central line of the chassis to be independently adjusted or combined to adjust and change the steering direction and the turning radius of the vehicle, so that the vehicle can realize all-directional driving and steering.

In order to further limit the above technical solution, the number of the driving units can be increased in pairs according to the carrying capacity of the aircraft tractor.

In the technical scheme, each driving unit comprises a steering motor, a traveling motor, a driving wheel, a large gear ring, an end face bearing, a bolt, a reduction box, a steering motor encoder, a traveling motor encoder, a brake and a cable; the steering motor is arranged on one side of the reduction gearbox shell, the output end of the steering motor is meshed with the bull gear ring, the output end of the reduction gearbox is connected with the input end of a driving wheel, the walking motor is arranged on one side of the reduction gearbox shell, the output end of the walking motor is connected with the input end of the reduction gearbox, the steering motor encoder and the walking motor encoder are arranged on the side of the reduction gearbox and correspondingly connected with the steering motor and the walking motor, and a brake is arranged on the driving wheel; the middle of the large gear ring is a hollow gap, an opening is formed in the side face of the upper portion of the reduction gearbox shell, a middle hole is formed in the top of the reduction gearbox shell, and cables of the steering motor, the walking motor, the steering motor encoder, the walking motor encoder and the brake penetrate through the opening and penetrate upwards through the hollow gap of the large gear ring from the middle hole in the top of the reduction gearbox shell to be connected with a corresponding motor driver.

In a further limitation to the above technical solution, the cable is an extra-soft grade wire cable.

The technical scheme is further limited, and storage batteries for providing electric energy for electric parts on the aircraft tractor are arranged on two sides of the chassis.

The utility model has the advantages compared with the prior art:

1. according to the scheme, four electrically-driven driving units capable of steering independently 360 degrees or +/-180 degrees are adopted as a power system and a steering system of the vehicle for the aircraft tractor, steering motors and walking motors of the four driving units are controlled through a vehicle-mounted main controller and a motor driver, and real-time adjustment is carried out according to feedback signals of encoders of the steering motors and the walking motors, so that the accurate control of the walking and steering actions of the tractor is realized, and the vehicle can well meet the condition of higher control accuracy requirement;

2. in the scheme, the four driving units are independently arranged at the four corners of the chassis, are not mechanically connected with each other, do not need other hydraulic devices for assistance, and are directly arranged on the chassis of the tractor, so that the structure is simple, the installation is convenient, the maintenance cost is low, the occupied space of the driving units is small, and the overall dimension of the tractor is convenient to reduce;

3. the drive structure of this scheme has ensured that the automobile body in the middle of two rear wheels of tractor can leave the breach, the tire of the aircraft undercarriage of being convenient for gets into automobile body central point and puts, thereby guarantee that the atress of four drive wheels of vehicle is even, reduce the motor power of single drive wheel, reduce the motor and generate heat, fully prolong equipment life, the security when the aircraft is pull to the improvement tractor, applicable advancing in the aircraft, the backset, the operation is pull in the turn, effectively avoid collision damage that the aircraft caused such as the inhomogeneous tractor afterbody or the car head perk of causing of aircraft tractor atress.

Drawings

FIG. 1 is a schematic view of the structure of the present invention;

FIG. 2 is a control schematic diagram of the driving unit of the present invention;

FIG. 3 is a front and rear view of the present invention;

FIG. 4 is a schematic view of the present invention in a left-right straight line;

FIG. 5 is a schematic view of the pivot steering of the present invention;

FIG. 6 is a schematic view of a middle wheel-clasping structure of the present invention;

FIG. 7 is a first turning driving diagram of the utility model with different turning centers corresponding to different radii at different positions;

FIG. 8 is a second schematic view of the present invention showing turning and driving with different radii corresponding to different positions of the rotation center;

fig. 9 is a third schematic view of the turning driving of the utility model with different turning centers corresponding to different radii at different positions;

FIG. 10 is a fourth schematic view of the present invention, wherein the turning center of the present invention is driven by turning with different radii at different positions;

fig. 11 is a fifth schematic view of the turning center of the utility model corresponding to different turning radii at different positions;

fig. 12 is a six schematic view of the turning driving of the utility model with different turning centers corresponding to different radii at different positions;

fig. 13 is a first schematic diagram of the oblique driving of the present invention;

fig. 14 is a second schematic diagram of the oblique driving of the present invention;

fig. 15 is a schematic structural diagram of the driving unit of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation 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 may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation. The use of the phrase "comprising one of the elements" does not exclude the presence of other like elements in the process, method, article, or apparatus that comprises the element.

Referring to fig. 1-15, embodiments of the present invention are detailed.

A rodless aircraft tractor with four-wheel drive comprises a chassis 1, wherein drive units 3 are arranged at four corners of the lower portion of the chassis 1, each drive unit 3 is independently arranged and is not mechanically connected with each other, a steering motor 6 and a walking motor 7 which can realize walking and steering functions are arranged on each drive unit 3, a vehicle-mounted main controller 4 is arranged at the rear portion of the chassis 1, a plurality of motor drivers 5 are arranged on the rear portion of the chassis 1 corresponding to the drive units 3, each motor driver 5 is electrically connected with the vehicle-mounted main controller 4, and each motor driver 5 is connected with the steering motor 6 and the walking motor 7 of the corresponding drive unit 3. The independent arrangement of the driving units 3 enables a gap 10 for mounting the wheel clasping mechanism 13 and facilitating the tire 12 of the aircraft landing gear 11 to enter the center of the vehicle body to be reserved in the middle of the chassis 1, and the vertical center line of the tire 12 of the aircraft landing gear 11 is superposed with the intersection of the diagonal connecting lines of the rotation center points of the four driving units 3. And storage batteries 2 for providing power sources for electric parts on the aircraft tractor are arranged on two sides of the chassis 1.

The number of the driving units 3 can be increased in pairs according to the bearing capacity of the aircraft tractor, and the intersection points of diagonal connecting lines of the central points of the driving wheels of the aircraft tractor of the formed multiple driving units 3 are superposed with the central line of the aircraft undercarriage 11, so that the uniform stress of the vehicle is always ensured.

Wherein, drive unit 3's structure is the existing horizontal integral drive unit overall arrangement structure in the market, adopts special customization scheme during the purchase, and concrete structure is as follows: as shown in fig. 15, each of the driving units 3 includes a steering motor 6, a traveling motor 7, a driving wheel 14, a large gear ring 19, an end face bearing 20, a bolt 21, a reduction box 22, a steering motor encoder 8, a traveling motor encoder 9, a brake 23, and a cable 15; the large gear ring 19 is fixedly connected with a girder of the chassis 1 through a bolt 21, the large gear ring 19 is connected with the upper part of a shell of a reduction gearbox 22 through an end face bearing 20 and ensures that the reduction gearbox 22 can smoothly realize steering within the range of 360 degrees or +/-180 degrees, the steering motor 6 is arranged at one side of the shell of the reduction gearbox 22, the output end of the steering motor is meshed with the large gear ring 19, the output end of the reduction gearbox 22 is connected with the input end of the driving wheel 14, the walking motor 7 is arranged at one side of the shell of the reduction gearbox 22, the output end of the walking motor is connected with the input end of the reduction gearbox 22, the steering motor encoder 8 and the walking motor encoder 9 are arranged at the side part of the reduction gearbox 22 and are correspondingly connected with the steering motor 6 and the walking motor 7, as shown in fig. 2, the travel motor 7 of each drive unit 3 corresponds to one motor driver 5 and one travel motor encoder 9, and the steering motor 6 of each drive unit 3 corresponds to one motor driver 5 and one steering motor encoder 8. A brake 23 is arranged on the driving wheel 14; the middle of the large gear ring 19 is a hollow gap 25, the side face of the upper part of the shell of the reduction gearbox 22 is provided with an opening 26, the top of the shell of the reduction gearbox 22 is provided with a middle hole 24, the cables 15 of the steering motor 6, the walking motor 7, the steering motor encoder 8, the walking motor encoder 9 and the brake 23 penetrate through the opening 26 and upwards penetrate through the hollow gap 25 of the large gear ring 19 from the middle hole 24 of the top of the shell of the reduction gearbox 22 to be connected with the corresponding motor driver 5, so that when the driving unit 3 rotates, the cables 15 connected with the driving unit 3 synchronously rotate together with the driving unit 3, and damages such as cable winding and bending cannot occur.

Preferably, the cable 15 is a super-soft wire cable, which can withstand long-term and frequent left-right rotation without being damaged, and can be continuously rotated left and right more than 100000 times without causing quality problem.

Four drive unit 3 in this aircraft tractor independently arrange in the chassis four corners, do not have mechanical connection each other, also need not other hydraulic means to carry out auxiliary drive or control, and direct mount is on the chassis 1 of tractor, simple structure, simple to operate, dimension guarantor are with low costs, and drive unit occupation space is little, is convenient for reduce the whole overall dimension of tractor. Meanwhile, the structure ensures that a gap 10 can be reserved on a vehicle body between two rear wheels of the tractor, so that tires 12 of an aircraft undercarriage 11 can conveniently enter the center position of the vehicle body, the vertical central line of each tire 12 is superposed with the rotation central points of the four driving units 3 and the intersection points of diagonal connecting lines of the central lines of the four driving units 3, and the tires 12 are fixed by the wheel clasping mechanism 13 of the chassis 1, so that the stress of driving wheels 14 of the four driving units 3 of the vehicle is uniform, the power of a steering motor 6 and a traveling motor 7 of each driving unit 3 is reduced, the heating loss of electric elements such as the steering motor 6, the traveling motor 7, a cable 15, a vehicle-mounted main controller 4, a motor driver 5 and the like is reduced, the service life of equipment is fully prolonged, the safety when the tractor pulls the aircraft is improved, and the tractor is suitable for forward, backward and turning pulling operations of the aircraft.

The aircraft tractor drives the running and steering actions of vehicles by four electrically-driven driving units 3 which can independently steer at 360 degrees or +/-180 degrees, controls the actions of steering motors 6 and traveling motors 7 of all the driving units 3 through an on-board main controller 4 and a motor driver 5 according to vehicle control signals (running, steering, accelerating, decelerating or brake lamp signals which can be sent by a remote controller or sent by a superior management system), controls the existing actions of the steering motors 6 and the traveling motors 7 of the four driving units 3 through the on-board main controller 4 and the motor driver 5 after receiving the signals, adjusts the angles alpha and beta of the axial lead of the driving unit 3 relative to the central line of a chassis 1 in real time after carrying out analysis calculation according to feedback signals of a steering motor encoder 8 and a traveling motor encoder 9, and adjusts the angles alpha and beta of the axial lead of the driving unit 3 relative to the central line of the chassis 1 through the angles alpha and beta of the four driving units 3, The beta is independently adjusted or combined adjusted, the steering direction and the turning radius of the vehicle are changed, and the vehicle can realize all-round running such as front-back straight running, left-right straight running, inclined running, running with different turning radii, pivot steering and the like. The precise control of the walking and steering actions of the tractor is realized by controlling the actions of the motor rotating speed, the torque, the acceleration, the deceleration, the braking and the like of the steering motor 6 and the walking motor 7. The actions of motor rotating speed, torque, acceleration, deceleration, braking and the like of the steering motor 6 and the walking motor 7 are controlled, and the actions can be sent to the motor driver 5 through the vehicle-mounted main controller 4, and the motor driver 5 can adjust parameters of the motors such as current, voltage, excitation frequency, magnetic field change and the like independently or in a combined mode to realize adjustment control.

The following are several walking and steering embodiments of the aircraft tractor:

as shown in fig. 3, the vehicle travels straight forward and backward, the axial line of the driving unit 3 is perpendicular to the central line of the chassis 1, α (α 1, α 2), β (β 1, β 2) is 90 °, the four driving wheels 14 have the same rotation speed and the same rotation direction, and the vehicle travels straight left and right.

As shown in fig. 4, the vehicle runs straight left and right, the center line of the drive unit 3 is parallel to the center line of the chassis 1, α (α 1, α 2), β (β 1, β 2) is 0 °, the four drive wheels 14 have the same rotation speed and the same rotation direction, and the vehicle runs straight left and right.

As shown in fig. 5, which is a schematic diagram of the pivot steering of the vehicle, the axes of the driving unit 3 intersect and the intersection point of the axes intersects with the vertical central line of the tire 12 of the aircraft landing gear 11, α (α 1, α 2) and β (β 1, β 2), the four traveling motors 7 rotate in the same direction and different directions, wherein the driving wheel 14-1 and the driving wheel 14-3 rotate in opposite directions and form a group of controls, the driving wheel 14-2 and the driving wheel 14-4 rotate in opposite directions and form a group of controls, and the pivot steering is realized around the intersection point of the axes of the driving unit 3. In this case, α 1 ═ β 1 and α 2 ═ β 2. Wherein the four driving wheels 14 are separately shown as driving wheel 14-1, driving wheel 14-2, driving wheel 14-3, and driving wheel 14-4.

Because the contact shapes and the areas of the front supporting plate 16 and the rear supporting plate 17 of the wheel clasping mechanism 13 and the tire 12 are in a symmetrical structure, and the main shaft 18 of the aircraft landing gear 11 is connected with the tire 12 through a universal rolling bearing mechanism, the inclination angle of the main shaft 18 of the aircraft landing gear 11 is calculated according to the vertical downward direction on the pressure of the wheel clasping mechanism 13, and the inclination angle of the main shaft 18 is not considered at this time, as shown in fig. 6.

Fig. 7-12 are schematic diagrams showing turning driving with different radii corresponding to different positions of the turning center O point of the chassis 1 of the vehicle: no matter the rotation center O point of the vehicle chassis 1 is at any position inside or outside the vehicle, four driving units 3 which can independently rotate 360 degrees or +/-180 degrees can be driven by the steering motors 6, so that the shaft axis intersection points of the driving units 3 are all located at the O point, and the omnibearing running of the vehicle at any angle and any radius is realized.

Fig. 13 and 14 are schematic diagrams illustrating the vehicle in a diagonal driving mode: the axial lines of the four driving units 3 can be parallel to each other no matter the axial lines of the driving units 3 form any included angle alpha with the vehicle body, and the oblique running of the vehicle in any direction can be realized.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims (6)

1. Rodless aircraft tractor with four-wheel drive, including chassis (1), its characterized in that: the four corners of the lower part of the chassis (1) are respectively provided with a driving unit (3), each driving unit (3) is independently arranged and is not mechanically connected with each other, each driving unit (3) is provided with a steering motor (6) and a traveling motor (7) which can realize traveling and steering functions simultaneously, the rear part of the chassis (1) is provided with a vehicle-mounted main controller (4), the number of the driving units (3) corresponding to the rear part of the chassis (1) is provided with a plurality of motor drivers (5), each motor driver (5) is electrically connected with the vehicle-mounted main controller (4), and each motor driver (5) is connected with the steering motor (6) and the traveling motor (7) of the corresponding driving unit (3); the independent arrangement of the driving units (3) enables a gap (10) used for installing a wheel clasping mechanism (13) and facilitating a tire (12) of an aircraft landing gear (11) to enter the center of a vehicle body to be reserved in the middle of the chassis (1), and the vertical center line of the tire (12) of the aircraft landing gear (11) is superposed with the intersection points of the diagonal connecting lines of the rotation center points of the four driving units (3).

2. The rodless aircraft tractor with four wheel drive of claim 1, wherein: the angle of the axis of each driving unit (3) relative to the central line of the chassis (1) is variable within the range of 360 degrees or +/-180 degrees, and the vehicle-mounted main controller (4) controls the driving units (3) through the motor driver (5) to enable the angles of the axes of the plurality of driving units (3) relative to the central line of the chassis (1) to be independently adjusted or combined to adjust and change the steering direction and the turning radius of the vehicle and enable the vehicle to realize omnibearing running.

3. The rodless aircraft tractor with four wheel drive of claim 1 or 2, wherein: the number of the drive units (3) can be increased in pairs according to the carrying capacity of the aircraft tractor.

4. The rodless aircraft tractor with four wheel drive of claim 3, wherein: each driving unit (3) comprises a steering motor (6), a walking motor (7), a driving wheel (14), a large gear ring (19), an end face bearing (20), a bolt (21), a reduction gearbox (22), a steering motor encoder (8), a walking motor encoder (9), a brake (23) and a cable (15); the large gear ring (19) is fixedly connected with a girder of the chassis (1) through a bolt (21), the large gear ring (19) is connected with the upper part of the shell of the reduction gearbox (22) through an end face bearing (20) and ensures that the reduction gearbox (22) can smoothly realize the steering within the range of 360 degrees or +/-180 degrees, the steering motor (6) is arranged on one side of the shell of the reduction gearbox (22) and the output end of the steering motor is meshed with the large gear ring (19), the output end of the reduction gearbox (22) is connected with the input end of the driving wheel (14), the walking motor (7) is arranged on one side of the shell of the reduction gearbox (22), the output end of the walking motor is connected with the input end of the reduction gearbox (22), the steering motor encoder (8) and the walking motor encoder (9) are arranged on the side part of the reduction gearbox (22) and are correspondingly connected with the steering motor (6) and the walking motor (7), and a brake (23) is arranged on the driving wheel (14); the middle of the large gear ring (19) is a hollow notch (25), the side face of the upper portion of the shell of the reduction gearbox (22) is provided with an opening (26), the top of the shell of the reduction gearbox (22) is provided with a middle hole (24), and cables (15) of the steering motor (6), the walking motor (7), the steering motor encoder (8), the walking motor encoder (9) and the brake (23) penetrate through the opening (26) and penetrate upwards through the hollow notch (25) of the large gear ring (19) from the middle hole (24) in the top of the shell of the reduction gearbox (22) to be connected with the corresponding motor driver (5).

5. The rodless aircraft tractor with four wheel drive of claim 4, wherein: the cable (15) adopts an extra-soft wire cable.

6. The rodless aircraft tractor having four-wheel drive of claim 5, wherein: and storage batteries (2) for providing electric energy for electric parts on the aircraft tractor are arranged on two sides of the chassis (1).

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