Vulkan Torsional Couplings

2011 December 5
by Chris Brown
Old Vulkan Bearing

Vulkan Couplers have an Out-put Bearing in the Housing

Vulkan coupler are one of the most common found on mega-yacht sized vessels.  This torsional coupling is found between the gear box and the engine and serves to dampen the torsional loads coming from the engine flywheel.  A polyurethane element (see second photo) acts as a gear “bumper”.  This particular Vulkan model was removed from a 87′ Ferretti with a ZF v-drive gear box and a Spicer cardan shaft.

The call first came in when a distinct thump was heard from that engine.  The diesel mechanics checked out their end and determined it was int he drive train.  That is when we get the call.

It was apparent that something was wrong when you could stand over the engine side of the cardan shaft and lift the assembly slightly – a worn bearing.  With this version of a Vulkan there is a large bearing that is part of the bell housing assembly.  This supports the weight of the u-joints on the cardan.

Vulkan Coupler Torsional dampening element

The Cardan and Vulkan have considerable weight and were, of course, in some tight places.  You could say this job took more brawn than brains.

The job does require the right tools and training.   The flanged coupler in the first photo must be removed from the shaft in order to replace the assembly on the housing.   The coupler is hydraulically fit on the shaft.  To remove and replace requires a high pressure pump and the right fittings.  Any other removal process (force, heat) will definitely damage the assembly beyond repair.

Vulkan Couplings – another High Seas Yacht Service specialty.

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