Marine Installation Manual
2021-08
6-15
6 Engine Dynamics
6.5 Axial vibration
X72DF
6.5
Axial vibration
The axial vibrations mainly depend on the dynamical axial system of the crank
-
shaft, the mass of the torsional vibration damper, and any free-end installations
or flywheel fitted to the crankshaft. Additionally, axial vibrations can be consid
-
erably influenced by torsional vibrations. This influence is called
coupling effect
.
It is recommended that axial vibration calculations are carried out at the same
time as torsional vibration calculations. To consider the coupling effect of tor
-
sional vibrations on axial vibrations, it is necessary to apply a suitable coupled
axial vibration calculation method.
As the shafting system is made up of masses and elastic connections, it is capable
of vibrating and resonating at several frequencies. This would result in excessive
stress in the crankshaft and in some cases can lead to excessive vibration of the
upper part of the engine.
Reduction of axial vibration
Axial vibration damper
To limit the influence of axial excitations and reduce the level of vibration, all
present WinGD engines are equipped with an integrated axial vibration damper.
In most cases, this lowers the axial vibrations in the crankshaft to acceptable
values, meaning no further countermeasures are required. No excessive axial vi
-
brations occur, neither in the crankshaft, nor in the upper part of the engine.
Figure 6
-
10 Example of axial vibration damper
The integrated axial vibration damper is mounted at the free end of the crank
-
shaft. It is connected to the main lubricating oil circuit. An integrated oil pressure
monitoring system continuously checks the correct operation of the axial vibra
-
tion damper.
Main bearing
Crankshaft flange
Axial vibration damper
SM-0096
