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17.03.2005 / TPa
AT Fahrzeugserie
AT Vehicle-Series
© 2005
Technische Beschreibung
Technical Description
Entlüftungssystem "Professional"
Da Kreiselpumpen keine selbstsaugenden Pumpen sind, wird das
benötigte Vakuum durch das Professional Entlüftungssystem er-
zeugt. Die Entlüftungspumpe ist auf dem Getriebe montiert. Sie
wird über einen Keilriemen angetrieben und ist nur für den
Entlüftungsvorgang einzuschalten.
Die Entlüftungspumpe ist eine manuell, auf Wunsch automatisch
gesteuerte, doppelt wirkende Kolbenpumpe. Die Gehäuseteile sind
aus korrosionsbeständigem Leichtmetall.
Die mit Dicht- und Führungsringen versehenen Kolbentöpfe sind
zu einer Einheit verschraubt und werden über einen kugelgelagerten
Exzenter mittels Gleitstein betrieben. Die bewegten Teile der
Entlüftungspumpe sind ölbadgeschmiert.
Saug- und Druckventile sind konzentrisch in den Ventildeckeln
angeordnet.
Computing maximum lift
Lift is measured from the surface of the
static source to the centerline of the
pump. The height of possible lift is not
affected by the angle of the intake hose,
but depends on the vacuum that the
pump (priming pump) can produce and
by the atmospheric pressure.
Theoretically, at sea level a pump can
lift water 10 m (33.8 feet). A perfect
vacuum is impossible with a fire pump
and there will be loss due to friction, so
the maximum lift is nearer to 6 - 7.6 m
(20 to 25 feet).
The height that water can be lifted
decreases with altitude by about 0.3 m
(1 foot) for each 300 m (1000 feet) of
elevation.
The weather also affects drafting, but
to a smaller degree.
Priming system "Professional"
Since a centrifugal pump is not a self suction pump, a professional
priming pump system is installed, which removes air from the
pump and the vacuum created serves to fill the pump with water.
The piston priming pump is mounted on the gear box. It is driven
by a V-belt and a spring loaded tension-roll. The priming pump has
to be engaged for the priming procedure only.
The priming pump is a manually controlled double-acting piston
pump which offers automatic control as an option.
The housing parts are made of corrosion resistant light alloy.
Two pistons, provided with sealing and guide rings, are fitted
together in a single unit. This double piston is driven by a sliding
pad, which is driven by an eccentric shaft.
The moving parts are oil bath lubricated and suction and pressure
valves are centrically arranged in the cylinder heads (valve
covers).
Summary of Contents for AT Vehicle Series
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