Mc Engine Description; Bedplate And Main Bearing; Frame Box; Cylinder Frame And Stuffing Box - Man B&W S50MC-C8-TII Project Manual

MAN B&W

MC Engine Description

Please note that engines built by our licensees
are in accordance with MAN Diesel drawings and
standards but, in certain cases, some local stand-
ards may be applied; however, all spare parts are
interchangeable with MAN Diesel designed parts.
Some components may differ from MAN Diesel's
design because of local production facilities or
the application of local standard components.
In the following, reference is made to the item
numbers specified in the 'Extent of Delivery' (EoD)
forms, both for the 'Basic' delivery extent and for
some 'Options'.

Bedplate and Main Bearing

The bedplate is made with the thrust bearing in
the aft end of the engine. The bedplate consists
of high, welded, longitudinal girders and welded
cross girders with cast steel bearing supports.
For fitting to the engine seating in the ship, long,
elastic holdingdown bolts, and hydraulic tighten-
ing tools are used.
The bedplate is made without taper for engines
mounted on epoxy chocks.
The oil pan, which is made of steel plate and is
welded to the bedplate, collects the return oil from
the forced lubricating and cooling oil system. The
oil outlets from the oil pan are normally vertical
and are provided with gratings.
Horizontal outlets at both ends can be arranged
for some cylinder numbers, however, this must be
confirmed by the engine builder.
The main bearings consist of thin walled steel
shells lined with bearing metal. The main bearing
bottom shell can be rotated out and in by means
of special tools in combination with hydraulic
tools for lifting the crankshaft. The shells are kept
in position by a bearing cap.
MAN B&W S50MC/MC-C-TII, S46MC-C-TII, S42MC-TII,
S35MC-TII, L35MC-TII, S26MC-TII

Frame Box

The frame box is of triangular plate welded or rib
design. On the exhaust side, it is provided with
relief valves for each cylinder while, on the ma-
noeuvring side, it is provided with a large hinged
door for each cylinder. The crosshead guides are
welded onto the frame box.
The frame box is bolted to the bedplate. The bed-
plate, frame box and cylinder frame are tightened
together by stay bolts.

Cylinder Frame and Stuffing Box

The cylinder frame is either welded or cast and
is provided with access covers for cleaning the
scavenge air space, if required, and for inspec-
tion of scavenge ports and piston rings from the
manoeuvring side. Together with the cylinder
liner, it forms the scavenge air space.
The cylinder frame is fitted with pipes for the
piston cooling oil inlet. The scavenge air receiver,
turbocharger, air cooler box, lubricators and gal-
lery brackets are located on the cylinder frame.
At the bottom of the cylinder frame there is a pis-
ton rod stuffing box, provided with sealing rings
for scavenge air. Oil scraper rings in the stuffing
box prevent crankcase oil from coming up into
the scavenge air space and polluting the crank-
case oil with combustion waste products.
Drains from the scavenge air space and the pis-
ton rod stuffing box are located at the bottom of
the cylinder frame.
MAN Diesel
1.06
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