Most engines are fitted with one or two viscous shear type torsional vibration dampers attached to the crankshaft at the opposite end to the flywheel.

Why are Dampers fitted?

Intermediate Condition The crankshaft damper is fitted to minimise the influence of torsional vibrations developing in the crankshaft. This keeps material stresses arising from these vibrations within permissible design limits. The damper, by reducing oscillations in the crankshaft to a low amplitude, prevents premature failures of the driven equipment.

How does the Holset Viscous Damper work?

The damper absorbs torsional vibration energy by the shearing effect of a highly viscous silicone fluid trapped between an inertia ring and the damper casing. The shearing of the fluid generates heat which is dissipated through the external surfaces of the damper.

Condition Monitoring

Condition monitoring of the damper is an essential preventative maintenance practice. This ensures the torsional vibration system of the vessel, generator or pump continues to function as per the design calculations, thus preventing early life failures. The internal condition and operating efficiency of the Holset viscous damper should be monitored by extracting small samples (1cc.) of silicone fluid for laboratory analysis removal of a silicone fluid sample is a simple process which should be initially carried out after 15,000 hours of engine operation or at the first major engine service.

Metaldyne will advise subsequent sampling intervals via the analysis report. Special sampling kits complete with instructions are available from Metaldyne Int UK Ltd or an appointed service representative

Metaldyne reports satisfy Survey Societies requirements
The Metaldyne laboratory report meets all the requirements of major survey classification societies like Lloyds, ABS, DNV BV for marine propulsion and auxiliary power installations at the 5 year survey.