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Cam less Engines
The cam has been an integral part of the IC engine from its invention.
The cam controls the "breathing channels" of the IC engines,
that is, the valves through which the fuel air mixture (in SI engines)
or air (in CI engines) is supplied and exhaust driven out.
Besieged by demands for better fuel economy, more power, and less
pollution, motor engineers around the world are pursuing a radical
"camless" design that promises to deliver the
internal-combustion engine's biggest efficiency improvement in years.
The aim of all this effort is liberation from a constraint that has
handcuffed performance since the birth of the internal-combustion
engine more than a century ago. Camless engine technology is soon to
be a reality for commercial vehicles. In the camless valvetrain, the
valve motion is controlled directly by a valve actuator - there's no
camshaft or connecting mechanisms. Precise electronic circuit controls
the operation of the mechanism, thus bringing in more flexibility and
accuracy in opening and closing the valves. The seminar looks at the
working of the electronically controlled camless engine, its general
features and benefits over conventional engine.
The engines powering today's vehicles, whether they burn gasoline
or diesel fuel, rely on a system of valves to admit fuel and air to
the cylinders and to let exhaust gases escape after combustion.
Rotating steel camshafts with precision-machined egg-shaped lobes, or
cams, are the hard-tooled "brains" of the system. They push
open the valves at the proper time and guide their closure, typically
through an arrangement of pushrods, rocker arms, and other hardware.
Stiff springs return the valves to their closed position
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