Figure 4-38.--Pump rotating parts (Model DC).
governed engine speed is the speed at which the force
pressed into the housing. The splines at the rear end of
of the governor springs is balanced on the governor arm
the shaft engage the internal splines in the front of the
pivot shaft. The pressure of the springs on the governor
rotor and turn the rotor with the shaft. A lip-type seal
arm can be varied with the throttle shaft lever, thus
prevents the entrance of engine oil into the pump, and
providing variable governed engine speed. The idling
another retains the fuel used for pump lubrication. The
spring provides sensitive governor action at low engine
governor weight retainer is supported on the forward
speeds. A governor linkage hook, connected to the
end of the rotor that is externally splined.
metering valve, is actuated by the governor arm.
The rotor contains the four pumping plungers, two
The drive end of the Model DC rotor has two bores
in each of the two pumping cylinders. Slots in the rear
that contain two plungers each. In the DC rotor, the
end of the rotor provide a place for the two
shoe that provides a large bearing surface for the roller
spring-loaded transfer pump blades (fig. 4-38). These
is carried in guide slots in the distributor rotor. The rotor
blades turn inside a pump liner and develop the
shaft rotates with a very close fit in the hydraulic head.
necessary pressure to charge the pumping cylinders.
A passage through the center of the rotor shaft connects
The mechanical flyweight variable speed-type
the pumping cylinder with one charging port and one
governor (fig. 4-39) is mounted on the drive end of the
discharge port. The hydraulic head, in which the rotor
distributor rotor. The action of the weights in their
shaft turns, has six charging ports and six discharge
retainer is transmitted through a sleeve to the governor
arm, and through a linkage to the metering valve. The
Figure 4-39.--Governor assembly (Model DC).