main applications - KS Motor

2.2.3 Types of construction and pump designs
Oil pumps are quite diff erent in their
type of construction and in their
appearance.
The pumping principle, the type of
drive and the housing design are the
most obvious distinctions.
Gear pumps
In a gear pump, the oil is transported
by the rotation of two gear wheels
between the teeth and the wall. The
interlocking of the gear wheels prevents
the oil from fl owing back into
the pan. So on one side overpressure
occurs whilst a vacuum is created
on the suction side.
Crescent pump
In a crescent pump, an external gear
wheel located in the pump housing
is arranged eccentrically to the inside
wheel. As is the case with a normal
gear pump, the oil is transported in
the spaces between the teeth. The
continuous rotation of the pump
creates a vacuum on the side where
the teeth separate from each other.
This is the suction side of the pump.
In the area where the teeth mesh
together again, an overpressure is
created. This is where the pressurised
oil is forced out.
The advantage of the crescent pump
over the normal gear pump is an
increased delivery rate, particularly
at low engine speeds.
Depending on the purpose, installation
location and delivery rate, oil
pumps that operate on the most diff erent
pumping principles are used.
chamber ()
BASICS
The most frequently used pump
construc tions are:
• Gear pumps
• Crescent pumps
• Rotor pumps
chamber ()
External wheel
Crescent
Inside wheel
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