RU2197403C2 - Two-section articulated cross-country vehicle steering system and its transmission - Google Patents

Abstract

FIELD: transport engineering. SUBSTANCE: vehicle wheels are made spherical. wheels are secured on horizontally arranged joints, and axle of joints are located in longitudinal plane of vehicle. Axles of joints of each pair of wheels are arranged with displacement relative to center of wheel sphere towards outer side of each wheel. Tilting of self-hand and right-hand wheels of two axles is provided by automobile type steering linkages installed in vertical plane square to direction of vehicle running. in proposed design of cross-country vehicle torque from engine is transmitted to wheel by means of flexible shafts and step-down reduction gears built into each wheel. Said transmission has no differentials. EFFECT: simplified design of system and performance of vehicle. 2 cl, 6 dwg

Description

 The invention relates to vehicles, in particular to a control system and improve driving performance of a two-section articulated all-terrain vehicle and its transmission.

 Known "Vehicle bridge" according to the description of the invention to and.with. USSR 1585201, IPC class B 62 D 9/00, published in BI 30.08.08.90 (1).

 This bridge is designed to improve vehicle controllability by stabilizing the movement of steered wheels under the influence of random wheel loads.

 The bridge contains steered wheels 1 mounted on swivel pivots 2, connected to a hydraulic cylinder 5, which is hydraulically connected to an elastic damping device 6. Under the action of lateral forces, the moment of these forces is transmitted to the cylinder rod 5, providing a pressure difference in the cavities of the device 6, the displacement of the control rod hydraulic cylinder, and therefore, the rotation of the steered wheels 1 in the direction of the angle of the wheel drive axle of the vehicle.

 The disadvantage of this vehicle bridge is that it provides only the road stability of the vehicle, and is not a factor ensuring the implementation of vehicle turns.

 The aim of the invention is the creation of a control system for a two-section articulated all-terrain vehicle and its transmission, which would ensure the maximum simplicity of the design of the entire control system, as well as significant improvements and transmissions of the all-terrain vehicle.

 The specified goal is achieved as follows.

 The wheels of the vehicle are made spherical. The wheels are mounted on horizontally mounted joints, and the axles of the joints are located in the longitudinal plane of the vehicle. In this case, the hinge axes of each pair of wheels are offset by a certain amount relative to the center of the wheel sphere to the outside of each wheel.

 The tilt of the left and right wheels of each of the two bridges is carried out by the trapezoid of the automobile type, installed in a vertical plane and perpendicular to the direction of movement of the vehicle.

 The proposed all-terrain vehicle transmission design provides for the transmission of rotation (torque) to the wheels from the engine through, for example, flexible shafts and reduction gears built into each wheel. At the same time, this transmission is made without differentials.

 As a remote analogue of the invention, it is possible to take "Vehicle bridge" according to the source of information (1).

 Figure 1 shows the bridge of the vehicle of the proposed control system of a two-section articulated all-terrain vehicle in rectilinear motion.

 In FIG. 2 - the same, when turning to the left of the bridge in the direction of the vehicle.

 Figure 3 shows a schematic drawing of the location of the planes of the wheel passing through the points of contact of each wheel with the road surface.

 In FIG. 4 shows the general arrangement of the wheels and transmission of a vehicle.

 In FIG. 5 shows the layout of the rods of the proposed control system in a rectilinear motion (for clarity, the control trapezoid is conventionally located in the plane of the drawing).

 In Fig.6 - the same as in Fig.5, but when turning (according to one of the possible schemes for driving a vehicle).

 The proposed control system of a two-section articulated all-terrain vehicle and its transmission consist of the following components, assemblies and parts.

On the beam 1, for example, of the front axle of the vehicle, two horizontal hinges A and A '(FIG. 1) mounted in the longitudinal plane are fixed. The axis 2 of the wheel 3 is fixedly attached to the lever 4 at a certain angle α.
The ends of the levers 4 of each wheel are fastened by a rod 5 to form a control trapezoid, and the control trapezoid is located in a vertical plane. The axles 2 of the wheels 3 are inclined a small angle β downward relative to the beam 1 to improve control performance. For example, when turning the vehicle to the left, on the left wheel, the diameter of the rolling wheel A ₂ -B decreases, and on the right wheel in the same case, the rolling diameter of the wheel A ₁ -B ₁ increases. In this case, the increase in the diameter difference between the right and left wheels occurs faster than when the axles 2 would be located horizontally.

 The proposed design of an articulated all-terrain vehicle consists of four wheels 3 of a spherical profile (figure 4). The rotation of the wheels from the engine 6 is transmitted by a system of flexible shafts 7 without differentials with reduction gears 8 built into the wheels. On the wheels there are only horizontal joints 9 located in the longitudinal plane of the vehicle, allowing the wheels to tilt only in the vertical transverse plane of movement of the all-terrain vehicle.

 The front part 10 of the articulated two-section all-terrain vehicle is pivotally connected to the rear part 11. On the front part 10, the steering wheel 12 is strengthened. The torque is transmitted from the engine 6 to the flexible shafts 7 via a gear mechanism 13. On separate straight sections, the flexible shafts can be articulated with using inflexible (rigid) shafts 14.

The inclination of the left and right wheels of each of the two bridges is carried out by the trapezoid of the automobile type installed in the vertical plane (Fig. 1, 2, 5, 6). In this regard, the slopes of the left and right wheels of each of the two bridges will vary (differ) (see figure 2). Due to the difference in the inclination of the wheels, they will touch the road surface with different rolling diameters, the planes of which are perpendicular to the axis of rotation of the ball (wheel), which will lead to the rotation of the vehicle’s bridge in the direction of the smaller rolling circumference (figure 2). Since both wheels in each axle move on the same surface, the construction of a rolling cone of movement of each axle to the left or right along the course occurs, despite the fact that the axles of the wheels do not lie on the same axis of the cone. Two “disks” A ₂ CB and A ₁ C ₁ B _{1 are} run in along the generatrix of the cone BB ₁ . As a result, the system rotates left or right, depending on the location of the top of the cone to the left or right in the direction of the vehicle (Fig. 2).

In connection with the change in the values of r ₁ and r ₂ (figure 2) during rotation, a restoring moment of straightness of movement equal to: P / 2 • r ₂ -P / 2 • r _{1 is formed} .

 On the beam 1 (figures 1 and 2) is constantly acting gravity P of the vehicle.

 When restoring the equality of the inclination of the wheels, they switch to rolling in equal circles (figure 1) and the system of two wheels moves in a straight line.

 The inclination of the steering trapezoid on the front and rear axles of the all-terrain vehicle should be the same and synchronized with the angle of rotation of the front and rear sections of the all-terrain vehicle relative to each other, which is an uncomplicated purely technical problem (FIGS. 5 and 6).

 When the axes of inclination of the hubs are located not in the center of the wheel spheres, but closer to the outer part of the wheel, an additional tilt of the frame with the body in the direction of rotation is achieved (which is desirable).

 In addition, when cornering, there is a restoring moment of straightness of movement (figure 2); this figure shows the external location of the axis from the center of the ball.

 The proposed all-terrain vehicle control design makes it a sufficiently maneuverable machine, capable of turning around with very small turning radii.

 When using the shape of the wheel as the surface of rotation of the ellipse (when the parameters of the ellipse are close to the circle, that is, the focal points of the ellipse should be quite close to each other (very far spaced centers of the ellipse will worsen the control of the all-terrain vehicle), even more stabilization of the straightness of movement and with lesser working slopes is possible wheel axles during turns; with some increase in the area of contact of the wheel with the road surface.

 The turning radius of the pair of wheels system also depends on the distance between the wheels being rolled around, that is, on the wheel track, the closer the wheels of the bridge are to each other, the smaller the radius of the pair of wheels can be rotated when they are tilted.

 The proposed all-terrain vehicle provides for the transmission of rotation from the engine to the wheels through flexible shafts. Such shafts are quite durable and wear resistant. Although they transmit small torques (of the order of 0.5-1.0 kgm with diameters from 12 to 16 mm), they can also rotate at high angular speeds (of the order of 2000-4000 rpm). Therefore, built-in reduction gears are used on the wheels, making it possible to obtain large torques on the axles of the wheels.

 Flexible shafts make it possible to refuse the use of any cardan gears, including cardans of equal angular speeds, which also greatly simplifies the design of the proposed vehicle. When using flexible shafts, it is possible to use inserts from hard shafts where the flexible shafts pass straight sections (figure 4).

 Since the flexible shafts in the braid (“armor”) are quite noisy and their efficiency is low, they can be used without “armor” in areas with only a bend in the path of transmission of rotation. Due to the possibility of laying flexible shafts almost anywhere - the layout of the all-terrain vehicle can be carried out quite optimally. The light weight of the shafts, the ability to install them quite arbitrarily, some damping of the transmitting loads, low price, ease of repair - all this speaks for their application in practice.

The proposed all-terrain vehicle, in contrast to the analogue, does not fundamentally need, when turning, a wheel overrun (differential), since when turning the wheels they (the wheels) rotate at the same angular speed, but each wheel rolls along the road surface at different rolling diameters A ₂ -B and A ₁ -B ₁ .

Literature
1. "Vehicle bridge" according to the description of the invention to AS USSR 1585201, IPC class B 62 D 9/00, published in BI 30.08.08.90

Claims (2)

 1. The control system of a two-section articulated all-terrain vehicle containing a bridge beam, vertical hinges mounted on the bridge with an axis of rotation of the wheels and a horizontal control trapezoid, characterized in that it contains wheels made spherical, the axles of the wheels are mounted on horizontally arranged hinges, and the axis of the hinges located in the longitudinal plane of the vehicle and offset from the center of the wheel sphere to the outside of each wheel, with the tilt of the left and right th wheels each of the two bridges is performed in the transverse plane relative to the longitudinal axis of the vehicle automobile type trapezoids arranged in a vertical plane.  2. Transmission of a two-section articulated all-terrain vehicle, characterized in that it comprises a reduction gearbox fixedly mounted in each wheel on a horizontal hinge, the torque to which is transmitted from the engine through a system of flexible shafts.

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