WÄRTSILÄ 46F Series, Product Manual

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4. Description of the Engine
4.1 Definitions
Fig 4-1 In-line engine and V-engine definitions (1V93C0029 / 1V93C0028)
4.2 Main components and systems
Main dimensions and weights are shown in section 1.4 Principal dimensions and weights.
4.2.1 Engine block
The engine block is made of nodular cast iron and it is cast in one piece.
It has a stiff and durable design to absorb internal forces and enable the engine to be resiliently
mounted without any intermediate foundations.
The engine has an underslung crankshaft supported by main bearing caps made of nodular
cast iron. The bearing caps are guided sideways by the engine block, both at the top and at
the bottom. Hydraulically tensioned bearing cap screws and horizontal side screws secure
the main bearing caps.
At the driving end there is a combined thrust bearing and radial bearing for the camshaft drive
and flywheel. The bearing housing of the intermediate gear is integrated in the engine block.
The cooling water is distributed around the cylinder liners with water distribution rings at the
lower end of the cylinder collar. There is no wet space in the engine block around the cylinder
liner, which eliminates the risk of water leakage into the crankcase.
4.2.2 Crankshaft
Low bearing loads, robust design and a crank gear capable of high cylinder pressures were
set out to be the main design criteria for the crankshaft. The moderate bore to stroke ratio is
a key element to achieve high rigidity.
The crankshaft line is built up from three-pieces: crankshaft, gear and end piece. The crankshaft
itself is forged in one piece. Each crankthrow is individually fully balanced for safe bearing
function. Clean steel technology minimizes the amount of slag forming elements and guarantees
superior material properties.
DAAB605814 4-1
4. Description of the Engine Wärtsilä 46F Product Guide