Electrohydraulic Torque Reaction Support - Audi 2003 A8 Technical Features

Engine, Mechanics
Electrohydraulic
torque reaction support
Top section
Connecting
pipe
Bellows cap
The purpose of torque reaction support is to
cushion the drive shaft and propshaft torque.
The position of the support bearing at the
front right of the engine is ideal, as this is
where the engine motion resulting from drive
shaft and propshaft torque accumulates.
The torque reaction support is divided into
two halves by the plastic ring, the sheet metal
ring and the isolation diaphragm. Both halves
are filled with fluid (glycol). The isolation
diaphragm is flexibly linked to the plastic and
sheet metal rings.
If the torque reaction support is subjected to
load, the fluid can be displaced between the
top and bottom section by way of a
connecting pipe, the dimensions of which are
such that it acts as a restrictor as of a defined
frequency.
32
Lock nut
Shell
Bottom
section
Stress-free alignment of the torque reaction
support is implemented by way of the lock
nut.
Isolation
diaphragm
Upper section of
nozzle plate
Plastic ring with sheet metal ring
Solenoid
When the solenoid is deenergised, vibration
causes the plastic ring with sheet metal ring
and isolation diaphragm to oscillate as well.
The moments are damped slightly and thus
transmitted to a lesser extent to the body.
As of an engine speed of approx. > 1,100 rpm
and a vehicle speed of > 5 km/h, the solenoid
is energised and attracts the sheet metal ring
together with the plastic ring.
This restricts the movement of the isolation
diaphragm, which can then only vibrate
slightly. In this case there is a high level of
vibration damping and the torque reaction
support is "hard".
SSP282_020