RU2786903C1 - All-wheel drive off-road vehicle with electric wheel drive - Google Patents

Abstract

FIELD: vehicles.

SUBSTANCE: invention relates to an all-wheel drive off-road vehicle with electric wheel drive, monocoque body and separate electric motors for the front and rear axles. Electric motors are placed directly on the axles of the vehicle in the form of complete units. Axles contain an electric motor, a final drive gearbox and a differential with a positive lock. The electric motor with a reducer is raised above the axis of rotation of the car wheels in a vertical plane. The input shaft of the steering rack is mounted on the axle and connected to the steering wheel by an intermediate shaft with a splined telescopic connection and hinges. The suspension of each bridge is made four-link with two lower main levers and two upper ones designed to compensate for the reactive moment. Upper and lower control levers are mounted at different angles to each other.

EFFECT: cross-country improvement.

6 cl, 5 dwg

Description

The invention relates to road transport, in particular to electric off-road vehicles.

Most modern four-wheeled off-road vehicles are built using a power plant based on a single internal combustion engine. The transmission of torque from the engine to the wheels is carried out through a transmission consisting, in the overwhelming majority of cases, of a clutch, a gearbox, a transfer case, cardan shafts, a main pair of gearboxes combined with differentials, and output axle shafts connected to the wheels.

A cross-country vehicle based on an internal combustion engine is a source of increased environmental pollution in terms of harmful emissions of combustion products, as well as acoustic noise and vibration.

Known electric cross-country vehicle Bollinger B1 (see, for example: https://www.drive2.ru/e/BqY2gEAAAyE?ysclid=l5wf0j0hw5719786872; see also international application WO2021101969A1, WO2021101969A1, IPC B60K1/04; B60L50/64; B60P1 /00; B62D63/02, published on May 27, 2021), which includes two electric drives designed to drive the front and rear axles, respectively. The electric drive units consist of an electric motor, an engine controller, an electric two-speed transmission, an electric parking lock and an electric locking differential. The drive units transmit power to the built-in brakes, which, in turn, are connected by a constant-velocity driveshaft to the wheel hubs, where another final drive gearbox is located.

This electric car is a classic frame structure, while current trends in the development of SUVs are a load-bearing body, the main advantages of which are lighter weight and a lower center of gravity (see, for example: https://zen.yandex.ru/media/ over9000/rama-protiv-nesuscego-kuzova-chto-luchshe-5b43b6629f388701f878a7b1).

Known electric pickup Rivian R1T, USA (see, for example: https://autokontact.ru/novyj-pikap-rivian-sovremennoe-elektricheskoe-avto-ot-novogo-proizvoditelya/), the transmission of which uses separate electric motors for the front and rear axles, however, in such vehicles, independent wheel suspension is used and power units with electric motors are mounted directly on the car body (carrying body). The disadvantage of such a scheme is the small suspension travel and the complex system of levers that go to each wheel and require more careful maintenance during operation.

In addition, the body structure of most off-road vehicles equipped with standard road tires, and not, for example, ultra-low pressure tires, does not imply the possibility of overcoming water obstacles by swimming, since the body of such vehicles does not have the required tightness, and the mass of the vehicle is large enough to provide buoyancy for counting submerged structural elements and wheels.

The above electric pickup Rivian R1T is selected as a prototype.

The problem solved by the present invention is to obtain the following technical result: the possibility of transporting people and goods through difficult areas of the country with minimal damage to the environment of the place of operation and minimal electrical energy costs for movement due to the high structural cross-country ability.

This task is solved by an all-wheel drive off-road vehicle with an electric drive of wheels with a load-bearing body and separate electric motors for the front and rear axles, in which, according to the proposal , electric motors are placed directly on the axles of the vehicle in the form of complete units that combine an electric motor, a gearbox of the main gears and a differential with forced locking, while the electric motor with a gearbox is raised above the axis of rotation of the vehicle wheels only in a vertical plane, and the input shaft of the steering rack mounted on the axle is connected to the steering wheel (steering wheel) by an intermediate shaft with splined telescopic connection and hinges, the suspension of each axle is made four-link, with two lower main levers and two upper ones designed to compensate for the reactive moment, while the upper and lower levers are installed at different angles to each other.

Each wheel can be equipped with a wheel reduction gear integrated with the wheel hub assembly.

To change the direction of the shafts in the area of the output shaft of the steering rack and steering column of the car, angular gearboxes can be used.

On the rear axle of the car, a steering axle can be installed, similar to the front one, which significantly increases the cross-country ability and maneuverability of the car.

It is advisable to make the body sealed, and equip the wheels with ultra-low pressure tires (see, for example: https://vektor4x4.ru/magazin/folder/avtoros?utm_source=yandex&utm_medium=cpc&utm_campaign=poisk&yclid=9990948080783982591).

The essence of the invention is illustrated by drawings, where in Fig. 1 shows the appearance of the car, Fig. 2 is a diagram of the transmission, in Fig. 3 - schematically the main view of the drive axle, in Fig. 4 is a schematic top view of the driving axle, in Fig. 5 - steering diagram.

The body of the car 1 is load-bearing, lightweight and made of aluminum alloy or composite materials. The lower part of the body is made airtight, in the shape of a boat and is designed to ensure the buoyancy of the vehicle, taking into account the maximum permitted weight. In the front part of the body there is one or two rows of seats, and in the rear part there is a luggage compartment equipped with a door. To protect against atmospheric influences, the car body has external glazing and sliding side doors. To ensure the safety of the driver and passengers in case of emergency, a safety cage is installed inside the body (not shown).

The main elements of the car are:

- Bearing sealed body.

- Specialized drive axles with electric power plant.

- Lever axle suspension system.

- Electronic control systems for the operation of vehicle devices and power plant.

- Accumulator battery.

- Climate control.

- Steering.

- Brake system.

The proposed four-wheel all-wheel drive off-road vehicle is built on the basis of two electric motors (power units) directly placed in specialized vehicle axles. In FIG. 2 shows a diagram of a car transmission, consisting of a front drive axle 2 and a rear drive axle 3. The front drive axle 2 of the car is equipped with a steering rack 4 and hub swivel units 5 that allow the wheels to deviate from the longitudinal axis of the car when a rotating force occurs on the steering wheel.

This vehicle differs from the well-known cross-country vehicles by specialized driving axles with electric power plants placed in them.

Known designs of the driving axle of the car, consisting of the main gear, differential for torque distribution between the wheels, axle shafts designed to transmit torque to the wheels, steering knuckles, hub assembly containing wheel bearings and a brake mechanism, as well as differential housing and covers semi-axes made of a round tube. The disadvantage of the design of such a bridge is the absence of an electric motor in the composition of the bridge, low ground clearance under the bridge due to the fact that the axes of the output semi-axes of the differential are placed in line with the axis of rotation of the wheels.

The design of the drive axle of the vehicle is also known (Patent RU2333847C2, IPC B60K 17/32, publ. 20.09.2008), in which the main gear is shifted vertically upwards to ensure high cross-country ability. The disadvantage of this design is the need to shift the final drive gearbox horizontally forward or backward, depending on the location of the bridge in the car, to accommodate the power beam of the bridge, as a result of which the internal and external hinges of equal angular velocities of the output shafts are forced to deviate from a straight line by a certain additional angle in the horizontal plane. This solution reduces the range of working angles of the constant velocity joints, which does not allow lifting the main gear reducer by a significant amount, and also significantly reduces the range of rotation of the steering wheels of the car.

The proposed design of the front drive axle (Fig. 3) allows you to place an electric drive motor directly on the bridge 2, 3 of the car in the form of a complete unit 6, which combines an electric motor, a final drive gearbox and a positive lock differential. To significantly increase the ground clearance under the bridge and use the entire range of angles of operation of the hinge of equal angular velocities, the axis of rotation of the output semi-axes of the differential and, accordingly, the electric motor with the gearbox itself, are raised above the axis of rotation of the vehicle wheels only in the vertical plane, without displacement of the axes relative to each other in the horizontal plane, as done in the invention RU2333847C2. The transmission of torque in such a layout is carried out using shafts 7 with hinges of equal angular speeds, or with cardan gears. To further increase the ground clearance, each wheel can be equipped with a wheel gear 8, combined with the wheel hub assembly. To accommodate the components, the body of the bridge 2, 3 is made of sheet steel or a tubular frame and has a spatial structure of the required strength. This design solution makes it possible to abandon the carrier beam, which in the above design does not allow placing the axis of the output shafts of the final drive differential directly above the axis of rotation of the wheels. The rear drive axle has a similar design and differs, as a rule, from the front one in the absence of a steering rack and the rigid connection of the wheel hubs to the axle body.

The study of the bridge design can be an independent development. Known designs can also be used, for example, the design of an electric drive with integration into a gearbox and differential, disclosed in patent RU174835U1 (IPK B60K 1/00; B60K 17/16; H02K 7/116; H02K 17/12; H02K 3/28, publ. 03/11/2019).

The proposed design also makes it possible to install an axle with swivel wheels on the rear axle of the vehicle, as in the front axle, thus significantly increasing the maneuverability of the vehicle in confined spaces, as well as increasing the area of the bearing surface on soft soils when the front wheels travel along one track, and the rear wheels are different.

The high geometric cross-country ability of the vehicle is achieved through the use of a four-link suspension of bridges 2, 3, shown in Fig. 4. The levers 9 are the main ones and are installed below the levers 10, which are designed to compensate for the reactive moment. The levers are attached to the subframe 11 of the car body 1 and the axle body 2, 3 through ball bearings or silent blocks. The rigidity of the suspension and the absence of lateral movements are ensured by installing the upper and lower arms at different angles to each other. This design solution, together with the use of long-stroke shock absorbers and pneumatic cylinders instead of traditional metal springs, allows you to create a high range of wheel movement in the vertical direction.

The rotation of the steered wheels in known vehicles with a dependent (bridge) wheel suspension scheme is performed either with the help of steering rods coming from the steering pendulum rigidly fixed to the vehicle frame and designed to convert the rotational motion of the steering wheel into the translational motion of the steering rods and steered wheels, or with using hydrostatic steering using an executive hydraulic cylinder mounted on the axle of the vehicle and a metering pump located on the steering column. The disadvantage of steering on tie rods is the presence of undesirable steering of the wheels when the axle is moved relative to the vehicle frame during movement, which necessitates constant operation of the steering wheel while driving on uneven surfaces, as well as the inability to provide significant movement of the wheels in a vertical plane, which negatively affects the cross-country ability car. The disadvantage of steering on the hydrostatic control principle is the lack of a mechanical connection between the wheels and the steering wheel (steering wheel), which significantly reduces the information content of the steering wheel, as well as the need to use a hydraulic station to create the required working oil pressure.

To eliminate the above shortcomings in the proposed design, the creation of a turning force on the steering wheel hubs is ensured by the steering rack 4, directly placed on the bridge 2 (Fig. 4) and designed to convert the rotational movement of the steering wheel into the translational movement of the rack rod. The steering diagram is shown in Fig. 5. To transfer the control force from the steering wheel (steering wheel) 12 to the input shaft 13 of the steering rack 4, an intermediate shaft 14 is used, going from the car body to the bridge 2 to the steering rack 4. To compensate for large displacements of the bridge relative to the body during suspension operation, the intermediate steering the shaft is equipped with splined telescopic connection 15 and hinges 16 and is located in the transverse plane of the vehicle. To change the direction of the shafts in the area of the input shaft 13 of the steering rack 14 and the steering column of the car, angular gearboxes 17 were used. in the steering rack.

Structural solutions implemented in the design of the vehicle, such as a bridge scheme of dependent wheel suspension with high ground clearance, high suspension travel due to the absence of an interaxle transmission and the use of separate electric motors for the front and rear axles of the vehicle, low vehicle weight due to the use of aluminum alloys in the structure body, constructive buoyancy provided by a sealed body structure, can achieve a significant reduction in energy costs required to move a car with people and goods through difficult terrain. In combination with the use of an electric power plant of a car that does not emit pollutants into the atmosphere during operation, the above technical solution makes it possible to obtain a significant synergistic effect in minimizing pollution by harmful substances of the ecological system of the place of operation and minimizing human impact on the environment.

This invention also opens up the possibility of using this all-wheel drive off-road vehicle for solving problems in an unmanned automatic mode, or using an external remote control. The absence of mechanical systems inherent in off-road vehicles with an internal combustion engine (clutch pedal, gearshift lever, transfer case operating mode selection lever) allows this vehicle to be used as a robotic off-road vehicle, or to control this vehicle remotely using a special transceiver complex.

Thanks to the use of two electric motors and gearboxes and their placement directly in the axles of the car, it was possible to achieve such a redistribution of the mass of the car, in which the main weight of the car is distributed directly above the axles of rotation of the wheels. In addition, the center of gravity of this vehicle is significantly lower than that of vehicles with an internal combustion engine or electric vehicles with a frame structure. Due to this, when the car is moving uphill, it is possible to maintain the downforce of the wheels to the ground and the coefficient of engagement of the coated tires. To enhance this effect, the electric motor of the front gearbox is shifted forward in the direction of travel relative to the axis of rotation of the front wheels, and the rear one is shifted back. In cars with a classic layout, the center of gravity is raised much higher and when climbing, the car's mass is redistributed, the front wheels are unloaded and lose grip on the road surface.

If necessary, this technical solution is able to provide electricity to external consumers in the case when it is not possible to use traditional power supply systems.

Claims (6)

1. An all-wheel drive off-road vehicle with an electric drive of wheels with a load-bearing body and separate electric motors for the front and rear axles, characterized in that the electric motors are placed directly on the axles of the vehicle in the form of complete units that combine an electric motor, final drive gearbox and differential with forced blocking, while the electric motor with the gearbox is raised above the axis of rotation of the vehicle wheels in a vertical plane, and the input shaft of the steering rack mounted on the axle is connected to the steering wheel by an intermediate shaft with splined telescopic connection and hinges, the suspension of each axle is four-link, with two lower main levers and two upper ones, designed to compensate for the reactive moment, while the upper and lower levers are installed at different angles to each other. 2. All-wheel drive vehicle according to claim 1, characterized in that each wheel is equipped with a wheel reduction gear, combined with the wheel hub assembly. 3. A four-wheel drive vehicle according to claim 1, characterized in that angular gears are used to change the direction of the shafts in the area of the output shaft of the steering rack and steering column of the vehicle. 4. All-wheel drive vehicle according to claim 1, characterized in that a steering axle similar to the front one is installed on the rear axle of the vehicle. 5. All-wheel drive vehicle according to any one of claims 1 to 4, characterized in that the body is sealed. 6. All-wheel drive vehicle according to any one of claims 1 to 4, characterized in that the wheels are equipped with ultra-low pressure tires.

Images