Moxy MT 31 - Crankshaft Damper

SHOP MANUAL MT26-31 - 06.2005
Engine
Tier-3 710655-
Ch 1 page 100
Crankshaft damper
Crankshaft damper
The power impulses from the connecting rause torsional oscillations in the crankshaft.
These oscillations are severest at certain engine speeds which vary with the design of the engine,
how it is loaded, etc.
Torsional oscillation is characterised as follows:
The flywheel (at the “rear” end of the crankshaft)
rotates at an almost constant speed throughout each revolution of the crankshaft. In relation to
the constant speed of the flywheel, the rotational speed of the front end of the crankshaft will
increase and decrease several times during each rotation.
To reduce the amplitude of the oscillation, a crankshaft damper is attached to the front end of
the crankshaft underneath a cover.
A ring of steel is incorporated in the circular and completely enclosed housing of the crankshaft
damper. The housing is bolted onto the crankshaft.
There is a heavy oil between the housing and ring which damps the relative movement between the
two. The oscillation at the front of the crankshaft is damped by the ring striving to rotate with even
speed. 1
10
©
Scania CV AB 2006-06:1
01:07-01
Crankshaft damper
The power impulses from the connecting rods
cause torsional oscillations in the crankshaft.
These oscillations are severest at certain engine
speeds which vary with the design of the engine,
how it is loaded, etc.
Torsional oscillation is characterised as follows:
The flywheel (at the “rear” end of the crankshaft)
rotates at an almost constant speed throughout
each revolution of the crankshaft. In relation to
the constant speed of the flywheel, the rotational
speed of the front end of the crankshaft will
increase and decrease several times during each
rotation.
To reduce the amplitude of the oscillation, a
crankshaft damper is attached to the front end of
the crankshaft underneath a cover.
A ring of steel is incorporated in the circular and
completely enclosed housing of the crankshaft
damper. The housing is bolted onto the crank-
shaft.
There is a heavy oil between the housing and ring
which damps the relative movement between the
two. The oscillation at the front of the crankshaft
is damped by the ring striving to rotate with even
speed.
1
1.Oscillation damper
1.Oscillation damper