RU2521457C1 - All-wheel-drive transmission /versions/ - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: all wheel drive transmission contains gearbox and reducing gears and has following features: reducing gears located on axles are connected with wheels locked by freewheel clutches directed to forward movement, and shaft/shafts between reducing gears have two resilient clutches or two gimbals and spline joint. The transmission can have two engines and two gearboxes. In the latter case continuum torque transfer to wheels can be provided. Next version of transmission: on reducing gear of front axle there is output of hypoid reducing gear shank or there is the second shank to which the intermediate shaft with two resilient clutches or two gimbals and spline joint is connected, and the shaft is connected with rear axle. As alternative, electric generator is connected with internal-combustion engine. The generator is connected by switch and wires with electric motors connected with rear or all wheels.

EFFECT: simplification of all-wheel-drive transmission design.

11 cl, 8 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. A disadvantage is the impossibility of upgrading an existing car of the formula 4 * 2 in an all-wheel drive car, since alterations are unacceptably difficult.

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, cost. As well as creating a design suitable for the modernization of cars of the formula 4 * 2.

OPTION 1. For this, this transmission, as usual, contains a gearbox and gearboxes, but differs in that the gearboxes located on the axles are connected to the wheels by lockable overrunning or ratchet couplings directed forward, and the shaft / shafts between the gearboxes have two elastic couplings or two cardan joints and spline connection.

Bridges can be two or more.

Elastic couplings should have the possibility of some axial movement (for example, as on the VAZ-2121), sufficient to compensate for the movement of bridges on bumps.

Figure 1 shows such a transmission, where: 1 - an engine, 2 - a gearbox with one or two clutches, 3 - gearboxes, 4 - lockable overrunning or ratchet clutches (hereinafter “overrunning”), 5 - elastic couplings or cardan transmissions with spline connection (hereinafter collectively “couplings”).

The transmission works as follows: when moving forward, the torque is transmitted to all wheels through overrunning clutches 4. At the same time, this and the following transmission options have one feature - it is desirable that all tires have the same size, have the same wear and pressure (or load). A tire with a larger diameter will pull slightly worse on a flat road.

When cornering, the front wheels go a longer way, and therefore, if there is no slippage, they will not pull. This gives the car with such a transmission a very useful quality - it is very well controlled in a controlled skid, since the rear wheels will have limited slippage. As soon as they slipped a little, they “catch up” with the front ones, they also begin to pull, and the torque on the rear wheels drops sharply - they stop slipping. This quality is very useful for vehicles that may require good handling at top speeds - for racing, fire, fighting.

When reversing, all or part of the overrunning clutches is blocked (depending on the condition of the road surface). Driving back on dry asphalt will be accompanied by slippage of one or almost all of the tires and an increased required torque. But since this mode is short-term and not high-speed, it does not matter.

OPTION 2. As you know, the clearance of existing cars is limited by the beam rear axle gearbox - it is the lowest point of the machine. Therefore, it makes sense to use split axles with wheel drives by means of CV joints (equal velocity joints). And it makes sense to fix gearboxes of such bridges on the car body motionless.

Such a transmission differs in that it can be simpler than the previous option - split axle gearboxes are interconnected by a shaft / shafts without elastic couplings, cardan or splined joints, the gearbox closest to the gearbox is connected to it via an elastic coupling or cardan-splined joint (to compensate vibration of the engine), and gearboxes of split axles are mounted on elastic cushions and are connected to the wheels via overtaking or ratchet couplings.

This slightly increases the load on the bearings of the shank (input shaft) of the hypoid gearbox (main gear), since the shank in this case perceives bending moments from deformation of the car body and from the torque of the wheels. But since the shank bearings during torque transmission experience very high loads from the contact forces in the gearing, this increase is not significant. In extreme cases, you can increase the bearing / shank bearings by one number.

If the shaft / shafts between the axles are too long and there is a risk of runout, one or more outboard bearings should be used.

The clutch in this embodiment may be on the gearbox and / or on the engine.

Figure 2 shows such a transmission. The designations and her work are the same. The hatched element means that it is fixed on the car body motionless (on elastic cushions).

OPTION 3. The practice of military operations has shown that a stalled or damaged vehicle, especially a combat vehicle, is itself an easy target and stops the entire convoy. To avoid this, you can install two engines on the machine.

That is, this transmission contains a gearbox, fixedly mounted on the car body, and connected to two engines via freewheeling or ratchet couplings with shafts with elastic couplings or cardan-splined joints.

This solution, in comparison with the combination of two engines, a clutch and a gearbox in a monoblock, as is usually done, gives the following advantages:

1. increases the combat survivability of the machine - even with the complete destruction of one engine, the second engine, located in a separate compartment and fenced off by an armored partition, can continue to move the car. At the same time, the locked first engine does not interfere with the remaining rotation, since the freewheel in this case freely rotates;

2. quick replacement of the engine in the field, especially with some deformation of the body, as there is no need to center the motor shaft and gearbox shaft.

The type of bridges can be any.

Freewheels can be located on engines or on the gearbox. The latter is preferable, since in this case the crumpled shaft will not interfere with the rest of the kinematics.

Figure 3 shows this version of the transmission - the designation and operation of the transmission are similar to option 1.

OPTION 4. The option is even more survivable when two engines are rigidly or with intermediate shafts connected to their two gearboxes, and the latter are connected to the near reducer through overrunning or ratchet couplings with shafts with elastic couplings or cardan-splined joints.

Overrunning clutches, as in the previous case, are preferable to install on the gearbox.

The bridge closest to the gearbox may have an increased size, since it contains almost two gearboxes on one output shaft.

This option is not illustrated graphically, since it differs little from the previous one. It works the same as the previous one. Although this option has greater survivability, it is somewhat more expensive than the previous one and more “capricious” - it is necessary to synchronize the shift of two gearboxes.

But on the other hand, this “capriciousness” can be used also for the benefit - with the computer control of the transmission when shifting gears, the following transmission operation algorithm is possible:

A) the first engine is disengaged by the clutch and its revolutions decrease / increase until the revolutions of the future transmission at a given speed, the second engine is transferred to double torque mode (if necessary, it is forced, for example, by supplying fuel with dissolved nitroglycerin);

B) the gear is shifted to the first gearbox;

C) the second engine is disengaged by the clutch and its revolutions decrease / increase until the revolutions of the future transmission at a given speed, the first engine is transferred to double torque mode (if necessary, it is forced, for example, by supplying fuel with dissolved nitroglycerin);

D) the gear shift of the second gearbox;

D) both engines come into the same operation in a new gear to a given mode of power.

Thus, the gear changes without loss of torque on the wheels, which is especially valuable when climbing uphill, when driving on sand, when driving on viscous waterlogged soil, or when towing.

THE FOLLOWING 5, 6, 7, 8th transmission options are suitable both for the design of new, especially 4-wheel cars, and for the simple modernization of front-wheel drive cars of the 4 * 2 formula in four-wheel drive cars.

OPTION 5. With the smallest alterations, the front-wheel drive car can be converted into four-wheel drive using the following transmission: on the front axle gearbox there is an output of the shank of the hypoid gearbox or (if this is not possible) there is a second shank to which an intermediate shaft with two elastic couplings is connected via a freewheel or ratchet clutch or with two cardan joints and a spline connection, and the shaft is connected to a gearbox mounted on the housing, similar to the front axle gearbox.

The freewheel may be lockable or non-lockable. The latter is cheaper, but deprives the car of the opportunity to get out of the mud in reverse.

In such a transmission, the unification of parts is maximum - the rear axle with drives and constant velocity joints is similar to the front. The hubs and bearings of the rear wheels are similar to the front ones. It is better to leave the rear brakes in order not to redo the hand brake device. Only a new elongated shank and an intermediate shaft with two couplings are required.

In FIG. 4 shows the fifth transmission variant, where all designations are the same. But circle 6 is a gearbox with a differential. The transmission works similarly to option 1, but with one note - if not all tires are equally worn, then it is recommended to put more worn tires on the rear wheels - there they have the ability to "overtake" the front wheels.

OPTION 6. If you add one more overrunning clutch to the previous version (the ratchet also applies to them) and remove the differential, you get a transmission that is about the same cost in which there is an output of the shank of the hypoid gearbox on the front axle gearbox or (if this is not possible) there is a second shank, to which an intermediate shaft is connected with two elastic couplings or with two cardan joints and a splined connection, and the shaft is connected to a gearbox connected to the wheels through the forward-facing locked or lockable freewheel or ratchet clutch.

In this case, the rear gearbox can be mounted on a beam axle or on a car body, and in the latter case it is connected to the wheels not only through overrunning clutches, but also via CV joints (the latter is preferable).

In terms of cross-country ability, this transmission is much better than the previous one - even with non-lockable overrunning clutches, when moving forward, it works like a bridge with a locked differential. That is, such a machine is not afraid of diagonal hanging.

Figure 5 shows this option. Designations and principle of operation are the same as in previous versions.

OPTION 7. If the rear elastic suspension beam interferes with the passage of the intermediate shaft (it is not designed for this in front-wheel drive cars), then it can be circumvented by applying the following transmission: the front axle gearbox has an output of the hypoid gearbox shank or (if this is not possible) there is a second shank to which an intermediate shaft is attached with a hinge of equal angular velocities, the shaft or constant velocity joint mounted on the car body on an outboard bearing, and the shaft is connected to a gearbox connected to the wheels.

Please note - elastic couplings or cardans with spline connection are no longer needed, since some designs of CV joints (for example, according to application No. 2012153546 / 11-085150) allow axial movement of the primary and secondary shafts. That is, the bending and axial movements of both parts of the intermediate shaft that occur during the operation of the suspension of the machine are compensated by a constant velocity joint.

Nevertheless, one elastic coupling can be left near the front axle - not so much to compensate for angular movements, but to compensate for the difference in the paths of the front and rear wheels when hitting an obstacle. After all, when driving over a ledge of a road, and when hitting a pit, the wheel path increases slightly, and the speed of this wheel also increases slightly. And so that the torque on these wheels does not disappear at this time, it is desirable that the kinematic connection between the axles be somewhat elastic. After hitting an obstacle with one wheel, the torque on it somewhat decreases, but after a few revolutions it aligns with other wheels due to the elasticity of the tires.

And this is another advantage of the transmission with overrunning clutches - if in a differential bridge a collision with an obstacle and, therefore, lengthening the path of one wheel causes the second wheel to brake through the differential, which is noticeably transmitted to the body as a small oncoming blow, then the transmission with overrunning clutches is spared of this.

Figure 6 shows this option. Designations and principle of operation are the same as in the previous versions, but 7 - SHRUS, 8 - outboard bearing.

OPTION 8. Hybrid transmissions are known in which the front wheels are driven by an internal combustion engine and the rear wheels are driven by electric motors from a battery (this invention is a prototype of this embodiment). Since most cars require all-wheel drive qualities only for a short time and for driving at a very low speed (as a rule, you will not be able to accelerate on a bad road), the following option is possible as an initial transmission and as a modernization transmission: with an internal combustion engine an electric generator is connected (for example, by a belt drive), which is connected by a switch and wires to electric motors connected through overrunning or connecting couplings to the rear or all wheels dstvenno or through gears.

Overrunning couplings can be non-blocking or blocking (the latter, of course, is better). But it’s better to use simply electric couplings (you can use couplings similar to starters' bendixes).

Some types of electric motors allow operation with sufficient efficiency at low rotational speeds. Gearboxes are optional for them.

It is possible to provide for a kinematic shutdown of the electric generator by applying a controlled disconnect clutch between it and the internal combustion engine.

Such a transmission allows all-wheel drive with speeds of only about 5-15 km / h (depending on the power of the electrical system). But it will turn out to be the lightest - the specific power of the best modern electric generators and electric motors reaches 6 kW / kg, and the efficiency of the best of them reaches 99%.

So that the driver does not forget to turn off the electric motors, the switch has a lock and turns off when the speed increases to a certain limit. Or at least it has an alarm that is triggered when a certain speed is reached (to avoid false triggering when the wheel is slipping connected to the speedometer).

In Fig. 7, an eighth transmission variant is shown. The designations are the same, but 9 - an electric generator, 10 - a wheel complex (electric motor, gearbox, disconnect clutch), 11 - a switch, 12 - wires.

This transmission works like this: on a poorly covered road section, switch 11 is turned on, and electric motors 10 drive the rear wheels.

In options 1, 2, 3, 4, 6, 7, the gearbox is connected to the wheels through overrunning clutches. To position both of these devices as compact as possible, overrunning clutches are located inside the hypoid gearbox.

On Fig shows such a gear. It contains a hypoid gear 13 located on a cylindrical sleeve 14, mounted in the bearings 15. A hypoid shank 16 interacts with the gear 13. Two rotors of two overrunning clutches 17 with roller or two are freely located inside the sleeve (centered by the drive axles and resting against each other). wedge-shaped locking elements (elements not shown). On wedge-shaped elements, it is desirable to have oil drainage grooves. In the right rotor 17 shows the axis of the actuator 18 with a freewheel lock device 19, interacting with a spline protrusion 20 on the rotor 17.

The gearbox works as follows: when, for example, ahead of one or two or three wheels, the overrunning clutches 17 slip in the hub 14, allowing the wheels to drive this section without a skid.

Claims (11)

1. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that the gearboxes located on the axles are connected to the wheels by lockable overrunning or ratchet couplings directed forward, and the shaft / shafts between the gearboxes have two elastic couplings or two cardan joints and a spline connection . 2. An all-wheel drive transmission comprising a gearbox and gearboxes, characterized in that the gearboxes of the split axles are interconnected by a shaft / shafts without elastic, cardan or splined joints, the gearbox closest to the gearbox is connected to it via an elastic coupling or a cardan splined joint, and gearboxes of split axles are mounted on elastic cushions and are connected to the wheels through overtaking or ratchet couplings. 3. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that it contains a gearbox fixedly mounted on the car body and connected to the engines through freewheeling or ratchet couplings with shafts with elastic couplings or cardan-splined joints. 4. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that the two engines are rigidly or with intermediate shafts connected to their two gearboxes, and the latter are connected to the near gearbox through overrunning or ratchet couplings with shafts with elastic couplings or cardan-splined joints. 5. The transmission according to claim 4, characterized in that with the computer control of the transmission when shifting gears, the following transmission operation algorithm is possible:
a) the first engine is disengaged by the clutch and its revolutions decrease / increase until the revolutions of the future transmission at a given speed, while the second engine is transferred to double torque mode or boosted, for example, by supplying fuel with dissolved nitroglycerin;
b) the gear is shifted to the first gearbox;
c) the second engine is disengaged by the clutch and its revolutions decrease / increase until the revolutions of the future transmission at a given speed, while the first engine is switched to double torque mode or boosted, for example, by supplying fuel with dissolved nitroglycerin;
d) the gear shift of the second gearbox;
d) both engines come into the same operation in a new gear to a given mode of power. 6. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that the front axle gearbox has an output of the hypoid gearbox shank or there is a second shank to which an intermediate shaft with two elastic couplings or with two cardan joints and splined is connected via an overrunning or ratchet clutch connection, and the shaft is connected to the rear axle, similar to the front. 7. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that the front axle gearbox has an output of the hypoid gearbox shank or there is a second shank to which the intermediate shaft is connected with two elastic couplings or with two cardan joints and a spline connection, and the shaft is connected with a gearbox connected to the wheels via forward-facing lockable or non-lockable freewheeling or ratchet couplings. 8. All-wheel drive transmission containing a gearbox and gearboxes, characterized in that the front axle gearbox has an output of the hypoid gearbox shank or there is a second shank to which an intermediate shaft with a constant velocity joint is connected, and the shaft or constant velocity joint is mounted on the car body on a suspended bearing, and the shaft is connected to a gearbox connected to the wheels. 9. Four-wheel drive transmission containing a gearbox and gearboxes, characterized in that an electric generator is connected to the internal combustion engine, which is connected by a switch and wires to electric motors connected via overrunning or connecting couplings to the rear or all wheels directly or via gearboxes. 10. The transmission according to claim 9, characterized in that the switch has a lock and turns off when the speed increases to a certain limit, or has an alarm when a certain speed is exceeded. 11. Transmission according to any one of claims 1, 2, 3, 4, 6 or 7, characterized in that the overrunning clutch is located inside the hypoid gearbox.

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