3.3.1. General information

The automatic transmission carries out functions of smooth inclusion of coupling at a troganiye from a place and optimum gear shifting at car movement.

Automatic boxes are equipped by four operated to transfers for advance. The third, fourth transfers at the blocked coupling can mechanically join bypassing the hydrotransformer.

The main knots of an automatic transmission is the following:

– a gidrotrasformator transferring a torque from the engine to a transmission. The blocking coupling allows to bypass the hydrotransformer and mechanically to switch the third and fourth transfers;

– planetary transmission. Is mechanical knot of an automatic transmission by means of which owing to continuous gearing of cogwheels and interaction of brakes and satellites it is possible to change transfer number practically without a rupture of a stream of capacity;

– oils operated by pressure multidisk couplings and brakes, and also a tape brake allow to establish necessary transfer numbers without a rupture of a stream of capacity and to stop rotating details. Unlike couplings, brakes are fixed on the transmission case;

– oil pump and radiator;

– couplings of a free wheeling for optimization of transfer of loading;

– main transfer;

– an electronic control system of hydraulics with the control unit for automatic transmissions. The control unit carries out gear shifting. The elements influencing operation of the control unit, the sensor of provision of a butterfly valve and sensors of frequency of rotation of the engine, frequency of rotation of a target shaft of a transmission, oil temperatures in a transmission are, etc.