supercharger

A supercharger is an engine-driven air pump that
supplies more than the normal amount of air into the
intake manifold and boosts engine torque and power.
It provides an instantaneous increase in power
without delay or lag associated with turbochargers.
Because it is driven by the engine, it requires
horsepower to operate and is not as efficient as a
turbocharger.
In basic concept, a supercharger is an air pump
mechanically driven by the engine itself. Gears,
shafts, chains, or belts from the crankshaft can be
used to turn the pump. This means that the air pump
or supercharger pumps air in direct relation to engine
speed.
types of supercharger
................................
-Roots-type supercharger :-
Named for Philander and Francis Roots, two brothers
from Connersville, Indiana, who patented the design
in 1860 as a type of water pump to be used in mines.
Later used to move air, and used today on two-
stroke cycle Detroit diesel and other supercharged
engines.
The roots-type supercharger is a positive
displacement design. All
air entering is forced through the unit.
-Centrifugal supercharger :-
Mechanically driven by the engine, similar to a
turbocharger but mechanically driven by the engine.
A centrifugal supercharger is not a positive
displacement pump and all of the air that enters is not
forced through the unit. Air enters a centrifugal
supercharger housing in the center and exits at the
outer edges of the compressor wheels at a much
higher speed due to centrifugal force.
Blade speed must be higher than engine speed so a
smaller pulley is used on the supercharger and the
crankshaft overdrives the impeller through an internal
gear box, achieving about seven times the speed of
the engine.
Examples of centrifugal superchargers include
Vortech and Paxton
Supercharger Service
Usually lubricated with synthetic engine oil inside the
unit, the supercharger oil level should be checked and
replaced as specified by the vehicle or supercharger
manufacturer. The drive belt should also be inspected
and replaced as necessary.