Water Pump - Kubota D650-B Handbuch

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SYSTEM
[AJ Cooling System
The cooling system consists of a radia­
tor (not included in the basic engine),
centrifugal water pump, suction fan
and thermostat.
The water is cooled through the radi ­
ator core, and the fan set behind the
radiator pulls cooling air through the
core to improve cooling.
The pump sucks the cooled water,
forces it into the cylinder block and
draws out the hot water. Then the
cooling is repeated. Furthermore, to
control temperature of water, a
thermostat is provided on the way.
When the thermostat opens, the water
moves directly to radiator, but when it
closes, the water moves toward the
water pump through the by-pass be ­
tween thermostat and water pump.
The opening temperature of thermos ­
tat is about 82°C (180°F).
(1) Radiator
(4) Cylinder block
(2) Suction fan
(5) Cylinder head
(3) Watsr pump (6) Thermostat
3-1 WATER PUMP
35
Q
Imino 17.7 Imp.gals/min,9.2 U.S. gals/min) of water is
forced into the crank case and cylinder head to cool them.
The impeller, of backward type, is bent as far as possible
from the center, in the opposite direction to rotation. The
bearing unit prevents cooling water from entering by a
special mechanical seal.
(1)
Water pump impeller
(2) Mechanical seal
(3) Water pump body
(4) Bearing unit
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