Wartsila ?31DF Series, Product Manual, Page: 194 / 216

Fig 17-1 Shaft locking device and brake disc with calipers
17.5 Input data for torsional vibration calculations
A torsional vibration calculation is made for each installation. For this purpose exact data of
all components included in the shaft system are required. See list below.
Installation
●
Classification
●
Ice class
●
Operating modes
Reduction gear
A mass elastic diagram showing:
●
All clutching possibilities
●
Sense of rotation of all shafts
●
Dimensions of all shafts
●
Mass moment of inertia of all rotating parts including shafts and flanges
●
Torsional stiffness of shafts between rotating masses
●
Material of shafts including tensile strength and modulus of rigidity
●
Gear ratios
● Drawing number of the diagram
Propeller and shafting
A mass-elastic diagram or propeller shaft drawing showing:
● Mass moment of inertia of all rotating parts including the rotating part of the OD-box, SKF
couplings and rotating parts of the bearings
●
Mass moment of inertia of the propeller at full/zero pitch in water
●
Torsional stiffness or dimensions of the shaft
●
Material of the shaft including tensile strength and modulus of rigidity
●
Drawing number of the diagram or drawing
Main generator or shaft generator
A mass-elastic diagram or an generator shaft drawing showing:
17-2 DBAE248994
Wärtsilä 31DF Product Guide 17. Power Transmission