Electronic and forced locking the differential on the UAZ

The main feature of the free differential can be called that in the case of a slip of a wheel on another, a torque will be transmitted, sufficient for a full-motion. Locking the differential on the UAZ allows you to increase the torque value on the right wheel, and also provide much more effective grip.

How to do it?

To ensure the lock, you must perform one of two possible actions:

• Limiting the possibility of rotation of satellites;
• Combining one of the semi-axles with the differential housing.

Depending on the degree, the differential lock on UAZ and other cars can be partial or full. The latter option provides a fairly rigid connection of components, when the torque could be completely transferred to the wheel, providing a much more effective grip.

Partial locking differential on UAZ differs in that its use has a limited amount of transmitted force between the components and, accordingly, increases the torque on the wheel with more effective grip.

Coefficient

The degree of growth of torque on free wheels is determined by the blocking ratio. In other words, the ratio shows the ratio of the moment of the free wheel to the value that is present on the skid. It should be correctly understood that for a completely free symmetrical differential the coefficient is 1, because the torque is always the same on the wheels, but the differential lock on UAZ and other cars raises its value to 3-5. The subsequent increase in the coefficient is extremely undesirable, since it often leads to a malfunction of the various transmission elements.

Where is it used?

Nowadays, on modern cars, both interlocking differential locking and locking of interaxial elements are used. In all four-wheel drive cars, it is often not produced, as this can have a negative impact on handling.

The interlocking differential is interlocked automatically or forcibly. The latter option provides for mandatory command from the driver, and therefore it is also called manual. Automatic and electronic differential lock is performed using specialized technical devices.

Why is this necessary?

To date, one of the most effective ways to increase the patency is the locking of the differential on the UAZ. DAK and other systems are installed today in any modern cars that were originally designed for active operation in off-road conditions.

The differential lock, like any other technical solution, has its own peculiarities, and in order to understand when it is better to use the lock, first you need to understand the basic principles of its implementation, and also to determine what changes in case of blocking this mechanism.

When is it better to use it?

The most effective airlock differential on UAZ, like other similar systems, becomes in those conditions when there is too much difference in the force of the clutch of the wheels. Thus, the maximum blocking efficiency is achieved when one wheel is completely detached from the support surface, which is quite a frequent phenomenon in the process of crossing various ridge obstacles.

Also worth noting is the fact that the hydraulic lock differential on the UAZ provides a much higher throughput in the presence of an uneven distribution of weight between the wheels of the bridge, for example, when the wheels on one side were in a deep clay track, while the other side is still riding higher On a dry surface. Accordingly, the smaller the difference in the cohesion of the wheels of the bridge, the less effective will be the use of the lock.

The axle differential is blocked mainly only if there is a very significant difference in the traction force between the rear and front axles. For example, when in the process of turning a car some wheel was in a ditch with water, while all the others continue to remain on dry ground. Under standard conditions, it often happens that when towing a single wheel, the tractive power of all others is significantly reduced.

What do I need to know?

Experienced travelers have an extremely simple rule - before moving off-road, you need to include inter-axle differential lock, while the rear inter-wheel element is blocked when overcoming any parts of the heavy off-road, while the front is only in exceptional cases and only when Rectilinear motion is envisaged.

At the same time, it is necessary to correctly understand that the locking of the SPRUT differential on UAZ, like other systems, does not increase the overall traction of the wheels with the roadway, but only provides a certain wheel with the full use of this force to create the necessary tractive effort.

Forced

This blocking is carried out mainly with the use of a special cam clutch, which provides a fairly rigid connection of the body of this element to one of the semi-axes. The cam clutch is closed by means of a specialized hydraulic, mechanical, pneumatic or electric drive.

The mechanical drive ensures the unification of cables, levers or a complete system, which includes both of these elements. In this case, the forced locking of the differential on the UAZ can be carried out by the driver by moving the lever to the correct position during the time when the car is stationary.

The hydraulic drive includes working and main cylinders. As an actuating element of such a drive, a specialized pneumatic cylinder is used. The electronic differential lock, that is, the forced type using an electric drive, involves using an electronic motor to close the coupling. Turning on the same lock is done by pressing a separate button located on the dashboard of the car.

A rigid forced block is used to ensure easier passage of complex areas, and then necessarily disconnected. In general, it is customary to use it when homemade locking differential on UAZ and other all-wheel drive cars.

Self-locking

The self-locking differential is a kind of golden mean between a completely free and completely blocked differential, because with its help the possibilities of both variants are realized.

In total, there are two main types of such devices: they are blocked from the difference between the angular velocities of the wheels and the torques. The latter include a disk differential, a system with a viscous coupling and an electronic lock. The locking is carried out depending on the difference in torque.

Installation of the differential lock on the UAZ is carried out by mounting the simplest disk symmetrical device with the addition of one or two packages of friction discs. A certain part of such disks has a rigid connection with the body of the device, while the other is connected with the semiaxis.

The principle of operation, which is used in the disk differential of increased friction, is completely based precisely on the force generated due to the difference in the speeds of rotation of each semi-axis.

In the process of rectilinear motion , the shafts of the semi-axle and the differential will rotate at exactly the same speed, and the friction package will rotate as a single element. If you increase the frequency of rotation of a particular semiaxis, that part of the discs that corresponds to it will also rotate faster, and a friction force will appear between the disks, preventing the possibility of increasing the rotational speed. The torque on the free wheel is continuously increasing, which ensures a partial differential lock on UAZ Patriot or any other car.

The degree of compression of friction discs can be variable or fixed, and each device requires its own devices. The setting of the differential lock on UAZ with a fixed compression ratio is realized by special reasons of constant rigidity, while a variable degree is provided by the use of a hydraulic drive.

The disc differential is used as an inter-wheel drive in most sports cars, as well as in vehicles with increased cross-country ability.

Viscous coupling

This element is a set of perforated disks located close to each other, a certain part of which has a rigid connection to the differential housing, while the others are combined with the drive shaft. All discs are housed in a sealed enclosure completely filled with viscous silicone fluid.

During the rotation of the differential housing with the drive shaft at the same speed, the set of installed disks will rotate as a single unit, and if the speed of the drive shaft increases, the part of the discs will also rotate faster, along with mixing the filled silicone fluid. The liquid itself, thus, gradually hardens, which ensures the locking of the differential on UAZ Patriot and other similar cars. When the equality of speeds is restored, the liquid again loses its properties and the coupling is unlocked.

In connection with the fact that in itself such an element is quite large in size, it is customary to use it mainly to provide locking of the interaxle differential. Also, the use of a viscous coupling is often found on its own, when it is connected to an automatic all-wheel drive system.

Due to the peculiarities of its construction, the viscous coupling is characterized by inertia, as well as a tendency to excessive heating, and in the case of braking, there is a conflict with the anti-lock braking system. That is why, regardless of whether an automatic or forced locking of the UAZ differential is installed, the use of this option is not recommended and is practically not used anywhere, with rare exceptions.

Electronic

Electronic locking is a separate function of a specialized anti-slip system. Its realization is carried out by means of automatic braking of the slipping wheel, which is accompanied by an active increase in the traction force on it. In this regard, on the wheel, which has a more effective grip, the torque begins to increase.

Worm

Worm self-locking differential allows to provide fully automatic locking, which depends on the difference between the torque on the semiaxis and the body. In the case of a slippage of the wheel, accompanied by a reduction in the torque, the worm differential is locked and the torque transferred to the free wheel afterwards. In this case, a partial lock is provided, the degree of which directly depends on the total amount of torque reduction.

Known systems of this type can be called Qualife and Torsen. The construction of such differentials is a full-fledged planetary gearbox, which consists of worm gears, while the leading ones can be located perpendicular or parallel to the semi-axles.

The main feature that distinguishes worm gears from analogs is that it can make other gears spin, but it can not rotate from the others. The worm gear is wedged, and this property is used to provide partial differential lock. You can install such a system without assistance. Homemade locking differential on UAZ and other cars using worm systems can be used for both interaxle and interwheel devices.