11.2
Crankshaft
11.2.1 Description of crankshaft
The crankshaft is forged in one piece and provided with counter-
weights fastened with hydraulically tensioned screws.
At the driving end of the engine, the crankshaft is equipped with a
V-ring for sealing off the crankcase, a combined flywheel/thrust bearing
and a split gear wheel for camshaft driving.
At the free end, there is a gear for driving of pumps and usually a
vibration damper.
The crankshaft can be rotated by a electrical turning device operating
the flywheel. Separate instructions for the vibration damper are sub-
mitted, if the engine is equipped with such.
11.2.2 Crankshaft alignment
The crankshaft alignment is always done on a thoroughly warm engine,
i.e. after running on high enough load during a sufficiently long time
to heat up both the engine and the foundation. Recommended values
are more than 60% load during more than 6 hours.
The crankshaft alignment should be carried out immediately after
the engine is stopped and rapidly but carefully. Only the crankcase
cover for the cylinder being measured should be opened and it should
be closed immediately after measuring. The crankshaft alignment can
be checked either by using a dial indicator or as an alternative an
electronic deflection indicator.
By using a dial indicator:
1 Rotate crank of the first cylinder
near BDC (bottom dead cen-
tre) and attach crankshaft dial indicator to the centre marks in the
two crank webs. The distance between the indicator and the con-
necting rod should be as small as possible.
2 Set indicator at zero.
3 Read deflections when rotating crank to rear side,
TDC (top
dead centre), operating side and BDC. Record readings in the
Measuring Record: “Crankshaft alignment”.
See also work steps
for both methods.
Note! During the alignment procedure the crankshaft should be rotated
in the direction of rotation, only. The indicator should not be turned
during the measurement.
34SG/32DF
Crank Mechanism: Crankshaft, Connecting Rod, Piston
200414-05
