RU2570978C2 - Four-wheel drive transmission (versions) - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to transmissions for four and more wheels drive. Claimed transmission incorporates the gearbox, clutch and reduction gearbox. Note here that overrunning clutches are arranged at the gearbox output or at axles downstream the reduction gears. All or some overrunning clutches are a locking design. Besides, the transmission can incorporate the gearbox, clutch and reduction gears, the flexible coupling being fitted upstream of the gearbox or the clutch. This transmission can have the two-shaft gearbox with two secondary shaft outputs, one to the front/front and rear axles and rear/rear axles. Optionally, the transmission is provided with the split front and rear axles secured at the vehicle body on resilient elements while shafts coupling said two gearbox outputs with the axles are rigidly engaged with the gearbox and axles. Note here that two secondary shafts of the gearbox can be inclined downward to the axles.

EFFECT: simplified design.

7 cl, 4 dwg

Description

The invention relates to transmissions of vehicles for driving 4 or more wheels.

Such transmissions are known, consisting, as a rule, of a differential or branching and lowering transfer case and cardan shafts, see, for example, US Pat. Russia No. 2462371 or utility model No. 29266. Their disadvantages are the great complexity and cost of all components of the transmission, the large occupied volume, heavy weight, and insufficient cross-country ability, in particular, the fear of diagonal hanging, in which a four-wheeled car with all the drive wheels cannot move. This is primarily due to the fact that these transmissions are a modernization of existing non-all-wheel drive transmissions. For example, the Niva transmission VAZ-2121 contains the same gearbox as the VAZ-2106. But if you design an all-wheel drive transmission initially, then you can apply other design solutions.

The objective and technical result of the invention is to simplify the design of all-wheel drive transmission, increase its cross-country ability and ride, reducing its weight, volume, and cost

OPTION 1. For this, this transmission, as usual, contains a gearbox (hereinafter referred to as “the box”), a clutch and gearboxes, but differs in that it has a two-shaft gearbox having two outputs of the secondary shaft - to the front (front) and rear (rear) ) bridges.

The main advantage of this design is that you do not need a transfer case.

The second advantage of the twin-shaft gearbox is that with the widespread use of raising the 5th gear, the twin-shaft gearbox is more advantageous than the three-shaft gearbox. It has only one gear when transmitting rotation, while the three-shaft gearbox in all gears except the direct one has two successive gears.

Moreover, it makes sense to arrange the gearbox separately from the engine, for example, on a 4-wheeled car - between two front seats, that is, approximately in the middle between the front and rear axles. In this case, the inclination of the shaft connecting the engine and the box will be small. The shaft is equipped with elastic joints, Hook joints, or joints of equal angular velocities - CV joints (hereinafter referred to as “joints”).

Clutch can be installed at the engine, or at the gearbox. But since the drive clutch often acts as a flywheel and crown for the starter, it’s better for the engine.

Such a transmission transmits rotation at the same angular speed to the front (front) and rear (rear) axles, which can lead to wheel slippage during bends. To avoid this, in such a transmission, overrunning clutches should be used at the exit of the box, or in axles after gearboxes. And in order to be able to move in reverse, all or part of the overrunning clutches must be locked. The use of overrunning clutches is preferable - the car is not afraid of diagonal hanging, and there is no need for a differential in the bridges (overrunning clutches in the bridge will allow one of the wheels to overtake the other).

OPTION 2. Particular attention should be paid to the location of the elastic coupling. Usually it is installed after the gearbox, where the range of torque transmitted by it in different gears, for example in the first lowering and in the 5th, can differ by 10 times. In this design solution, it can be installed before the gearbox (counting from the transmission of torque), where the torque transmitted by it does not depend on the gear applied, but depends only on the engine mode.

It can even be installed before the clutch. This has twofold consequences - the movement of the car will become smoother, but the engine should not have dead spots, that is, it should have 6 or 3 (in the two-stroke version) cylinders.

Figure 1 shows the transmission of options 1 and 2. Engine 1 through the clutch 2 and the elastic coupling 3 transmits rotation to the twin-shaft gearbox 4 using the shaft 5 with hinges 6 (elastic, Hooke or CV joints). On both sides of the box, rotation is transmitted by shafts 7, 8 with hinges 6 to bridges 9, 10. It is advisable to use a “split” rear axle.

The transmission works as follows: the rotation of the engine is effectively damped by the elastic coupling 3, then by the shaft 5, preferably with CV joints, the rotation is transmitted to the box 4 and then, through the desired gear, to the axle gearboxes 9, 10.

OPTION 3. This transmission allows you to apply a constructive solution that simplifies it even more. If you apply "split" front and rear axles (the gearbox transmits rotation to the wheels through shafts with CV joints) and fix these bridges on the car body with elastic elements, then the shafts connecting the two outputs of the box to the bridges can be rigidly connected to the box and bridges without any hinges. In this case, shafts are preferably made thin so that they have limited flexibility. And the bearings of the box and axles should have increased strength in order to absorb not only the forces from gearing in the teeth of the gearbox, but also the longitudinal and transverse loads on the shafts. This load arises from the transmission of torque to the wheels and from deformations of the body on road bumps. Since the box and axles are attached to the body, they do not experience other mutual efforts.

The shafts may have an intermediate outboard bearing.

Figure 2 shows the transmission of option 3. As in figure 1, the engine 1 through the clutch 2 and the elastic coupling 3 transmits the rotation to the twin-shaft gearbox 4 using the shaft 5 with hinges 6 (elastic, Hooke or CV joints). On both sides of the box, rotation is transmitted by shafts 7, 8 rigidly connected to it and with bridges to bridges 9, 10.

The transmission works in the same way as in option 1.

With such a transmission, the bottom point of the box is at a height above the ground equal to the radius of the wheel minus the distance between the bottom of the box and the secondary shaft. With wheels of 17R285 / 65 size, the wheel diameter will be about 802 mm, and if the size of the box down from the secondary shaft is 100 mm, then the clearance to the box will be about 290 mm, which is quite enough for a jeep type car.

OPTION 4. However, if the clearance of 290 mm is not enough, then you can use a special box. This gearbox contains one input shaft and two output shafts, inclined downward in the direction of the bridges. This will raise the box to the desired clearance.

The connection of the box with the bridges can be either the first or the third one - rigidly.

In such a two-part gearbox, in each part, the lower gears are closer to its middle (since the diameter of the secondary lower gears is larger), and the higher gears are closer to its ends.

Figure 3 shows such a box, where: 11 - the primary shaft with two sets of gears 12, and 13 - the secondary shaft with gears 14.

The box works like two twin-shaft conical boxes.

It is clear that the gearing in such a box is “slightly” conical, and that, in fact, these are two separate boxes that must be controlled synchronously. For this, there are control rockers in the box, with their two shoulders, using rods, synchronously control the gear shift in two parts of such a box.

Figure 4 shows one of such rockers, where 15 is a rocker, 16 is a thrust to the gearshift clutch.

The box control works like this: when you turn the rocker 15 in any way, its shoulders are synchronously moved by the gearshift clutch rods 16 (not shown).

Synchronous switching, in fact, of two boxes, requires an elastic coupling at one or both of its outputs. Otherwise, the inclusion of one box may prevent the inclusion of the other (both boxes are connected to each other across the road using wheels).

The use of this transmission will allow you to create a simple, reliable and cheap car with maximum all-terrain qualities.

Claims (7)

1. Four-wheel drive transmission containing a gearbox, clutch and gearboxes, characterized in that at the exit of the box or in the axles after the gearbox there are overrunning clutches, all or part of the overrunning clutches being locked. 2. All-wheel drive transmission containing a gearbox, clutch and gearboxes, characterized in that the elastic clutch is installed before the gearbox or before the clutch. 3. All-wheel drive transmission containing a gearbox, clutch and gearboxes, characterized in that it has "split" front and rear axles mounted on the car body on elastic elements, and the shafts connecting the two outputs of the box with axles are rigidly connected to the gearbox and axles . 4. All-wheel drive transmission containing a gearbox, clutch and gearboxes, characterized in that it has a two-shaft gearbox having two outputs of the secondary shaft - to the front (front) and rear (rear) axles, and the gearbox contains one primary shaft and two secondary shaft tilted down towards the bridges. 5. The transmission according to claim 4, characterized in that in such a gearbox consisting of two parts, in each of its parts, the lower gears are closer to its middle, and the higher gears are closer to its ends. 6. The transmission according to claim 4, characterized in that the box has control rockers, with two arms using synchronous rods, simultaneously controlling gear shifting in two parts of such a box. 7. The transmission according to claim 4, characterized in that it has an elastic clutch on one or both outputs of the gearbox.

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