Self-Study Program

24
Function of the shift elements
Clutches and brakes
The function of the shift elements is explained here
using clutch K2, which is exemplary of clutches K1
and K3, as well as brakes B1 and B2.
Unlike the clutches, the brakes require no dynamic
pressure compensation, because their clutch
pistons and cylinders are non-rotating, and
therefore are not subject to a dynamic increase
in pressure (refer to page 26).
The shift elements are actuated hydraulically.
Pressure oil is supplied to the shift elements by the
valve assembly through stationary and rotating
ports in the gearbox housing, on the shafts and
other components.
Lube oil is supplied to the bearings and the shift
elements in the same way.
The clutch plate carriers are perforated, allowing
the oil (ATF) to flow through each clutch from the
inside outwards (normally when the clutch is open).
The design of the lined plates and the centrifugal
force are both conducive to oil flow through the
clutches.
Gearbox subassemblies
Clutch piston
Coil spring
Outer plate carrier cum clutch piston
cylinder
Baffle plate
Inner plate carrier
Clutch plates
(steel plates and lined plates)
Clutch K2 - open
Pressure compensation
chamber
Output shaft
367_054
Lube oil
Pressure port
Clutch K2
Gearbox housing
Transmission shaft -
connected to the
turbine shaft
high 0
Oil pressure
Planet carrier PT2
Clearance