2. Functional description

2.1 Transmission design

The main components for power transmission in Voith DIWA automatic transmissions are the hydrodynamic torque converter as well as the input and output-side planet gears with multipledisk clutches and brakes. Items in ( ) are explained below.

On the input side of the converter (C) are the pump brake (e) and the differential transmission (B),

–in the 3-speed design with one planetary transmission (see below),

–in the 4-speed design with two planetary transmissions (see next page), as well as the following clutches:

–input clutch EK (c),

3-speed transmissions (D 823.3E, D 851.3E, D 863.3E)

4 Voith. Oil and Control Circuit Diagrams DIWA.3E

–lock-up clutch DK (d),

–step-up gear clutch (d1) on 4-speed design.

On the output side of the torque converter there are two more planetary transmissions (D):

–the turbine transmission (l), in which the mechanical and the hydraulic power train of the first gear (DIWA drive range) converge, with the turbine brake TB (f),

–the transmission for the reversing gear and the converter brake (k) with the reverse gear brake RB (g).

A hydrodamp (b) on the transmission input damps engine vibrations.

The transmissions are shifted electro-hydraulically, the shift commands are issued by the electronic control unit.

The heat exchanger (i) for dissipation of the transmissions heat is linked to the engine coolant circuit.

4-speed transmissions (D 854.3E, D 864.3E)

Voith. Oil and Control Circuit Diagrams DIWA.3E 5