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Camless engine with elctromechanical valve
actuator
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 with
electro-mechanical valve actuator, 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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