O.S. Engines Rotary 49PI - Manual (Page 8)

OPERATING PRINCIPLE
In place of the piston and cylinder of a
conventional reciprocating engine, the Wankel
motor has a three-lobe rotor which moves in a
circular path, while rotating about its own axis,
THE NSU/WANKEL SYSTEM
Now available in a new and improved
PI(peripheral inlet) model, its outstanding
features remain its high specific power output,
its almost total freedom from vibration, its
relatively low noise level and its compact
shape.
This highly successful application of the
NSU/Wankel System to a power unit of
miniature proportions, was only made possible
by the expertise of O.S. research and
development engineers and by the high levels
of precision craftsmanship achieved in its
tooling and manufacture.
within a housing having an epitrochoidal bore -
i.e. a wide-waisted figure-of-eight
shape.Planetary rotation is controlled by an
eccentric shaft, an internally-toothed gear and
a fixed pinion mounted centrally on the rear
cover plate. The tips of the rotor are in
continuous contact with the housing, forming
three chambers, each of which changes in
volume, with rotation, to effect suction,
compression, expansion and exhaust phases,
as in a four-stroke reciprocating engine.
Spring-loaded tip seals on the rotor prevent
gases from passing from one chamber to the
adjoining one and the rotor uncovers ports, as
in a two-stroke engine, to control intake and
exhaust timing.
The engine is fitted with a conventional throttle
type carburettor that gives smooth and
progressive control of engine speed from idling
to full power. It is also supplied with a compact
matched muffler that very effectively
attenuates exhaust noise without causing
undue power loss.
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