General Description Of Engine Components - Robin America EX30 Service Manual

4. GENERAL DESCRIPTION OF ENGINE COMPONENTS

4-1 CYLINDER AND CRANKCASE
The cylinder and crankcase are aluminum die-casting
as a single piece. A special cast iron cylinder liner is
molded into the aluminum die-casting.
The crankcase has a mounting surface on the output
shaft side to which the main bearing cover is attached.
The cylinder is inclined to the right at an angle of 25
degrees from the horizontal as viewed from the output
shaft side.
4-2 MAIN BEARING COVER
The main bearing cover is an aluminum die-casting,
which is mounted on the output shaft side of the
crankcase. By removing the main bearing cover, the
inside of the engine can be inspected with ease. Pilots
and bosses are machined into the cover to facilitate the
direct coupling of the engine with machines such as
generators and pumps. There is an oil fi lling port, with
oil gauge, on either side of the cover.
4-3 CRANKSHAFT
The crankshaft is made of spheroidal graphite cast
iron, and the crank pin is high-frequency induction-
hardened. The crank sprocket used to drive the chain
and the gear used to drive the governor gear are
pressed into the output end of the shaft.
4-4 CONNECTING ROD AND PISTON
The connecting rod is a specially heat-treated
aluminum alloy die-casting. Its large and small
ends function as bearings. A splasher built into the
connecting rod lubricates by splashing engine oil.
The piston is an aluminum alloy casting with grooves
for mounting two compression rings and one oil ring.
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