Differential of increased friction - what is its special feature?

Differential from the point of view of mechanics is considered as a device that distributes torque between input shafts. It is located in the car drive. The differential of the car, respectively, distributes the torque from the input shaft of the gearbox or cardan between the semi-axles of the wheels of the car equally.

The differential is necessary for the driving wheels to rotate at different angular speeds. When turning, the inner wheel of the car passes a shorter arc than the outer one. And if the wheels rotate at the same speed, then one of them must enter the turn with a slip. This, in turn, will negatively affect the condition of tires and on handling. Also, the differential transfers the torque to the driving axis continuously.

If the car has one driving axle, the differential is located on it, if the car is four-wheel drive, then it has three differentials - on the leading axles and between them. If the driving axle of the car is doubled, then on each axis there is a differential, as well as on cars with an all-wheel-drive. However, on such machines with the full drive on, it is not recommended to drive on dense coatings.

The differential of increased friction (or differential with increased internal resistance, abbreviated to RPA) differs from the usual in that the angular velocities of the input shafts are not equal. This is true for off-road driving. The differential of the increased friction allows to continue movement in a situation when one wheel of a leading axis has no contact with the road. Limiting the difference in the angular speeds of the wheels allows the transfer of a useful moment, while at least one of the wheels has contact with the road.

Now there are two types of differentials of increased friction used in modern automotive industry. The first type is a differential that is sensitive to the difference of moments (or torsion). The second type is the speed sensitive (created on the basis of a viscous coupling). This type is the most popular, because it is less demanding for maintenance.

The construction of the differential of the viscous type is simpler in comparison with other types of differentials of increased friction. A distinctive feature is that the work of this type is the smoother.

Differential can be installed on different cars. Experts know, for example, the differential of increased friction VAZ. There are also self-locking differentials worm-type. For example, the differential of increased friction type "Quife" (QUAIFE). It is designed for Cars with front-wheel drive. This differential will help to fully realize the torque of the ICE on the ice or in the event that the traction on the driving wheels is in excess. A wheel that has contact with the road receives an additional moment, while unloading a wheel that has lost contact with the road or skidding on ice. Passability of the car is getting better, overclocking in the winter season is the most dynamic. In addition, the controllability and sensitivity of the accelerator pedal is improved.