4.
Description of the Engine
4.1
Definitions
Figure 4.1
In-line engine and V-engine definitions (1V93C0029 / 1V93C0028)
4.2
Main components and systems
The dimensions and weights of engines are shown in section
1.6 Principal dimensions and weights
4.2.1 Engine Block
The engine block, made of nodular cast iron, is cast in one piece for all cylinder numbers. It has a stiff and
durable design to absorb internal forces and enable the engine to be resiliently mounted without any inter-
mediate foundations.
The engine has an underslung crankshaft held in place by main bearing caps. The main bearing caps, made
of nodular cast iron, are fixed from below by two hydraulically tensioned screws. They are guided sideways
by the engine block at the top as well as at the bottom. Hydraulically tightened horizontal side screws at
the lower guiding provide a very rigid crankshaft bearing.
A hydraulic jack, supported in the oil sump, offers the possibility to lower and lift the main bearing caps,
e.g. when inspecting the bearings. Lubricating oil is led to the bearings and piston through this jack. A
combined flywheel/thrust bearing is located at the driving end of the engine. The oil sump, a light welded
design, is mounted on the engine block from below and sealed by O-rings.
The oil sump, a light welded design, is mounted on the engine block from below and sealed by O-rings.
The oil sump is available in two alternative designs, wet or dry sump, depending on the type of application.
The wet oil sump comprises, in addition to a suction pipe to the lube oil pump, also the main distributing
pipe for lube oil as well as suction pipes and a return connection for the separator. The dry sump is drained
at either end (free choice) to a separate system oil tank.
4.2.2 Crankshaft
The crankshaft design is based on a reliability philosophy with very low bearing loads. High axial and tor-
sional rigidity is achieved by a moderate bore to stroke ratio. The crankshaft satisfies the requirements of
all classification societies.
The crankshaft is forged in one piece and mounted on the engine block in an under-slung way. In V-engines
the connecting rods are arranged side-by-side on the same crank pin in order to obtain a high degree of
standardization. The journals are of same size regardless of number of cylinders.
Product Guide Wärtsilä 34DF - 3/2012
21
Product Guide
4. Description of the Engine
