Page 2-22
Dec/05
DESCRIPTION AND OPERATION
61-00-75
Propeller Owner's Manual
175
The governor uses an internal pump that is driven by an
accessory drive from the engine. This pump uses an engine
oil supply and increases the engine oil pressure for supply
to the propeller. Engine speed sensing hardware within the
governor controls the supply of oil to, or drain of oil from the
propeller, resulting in a change of blade pitch to maintain
constant engine speed.
Oil from the engine-driven governor is supplied to the
propeller mounted hydraulic cylinder through the engine
shaft and propeller hub. Increasing the oil volume within the
hydraulic cylinder decreases blade angle to increase engine
RPM. Decreasing the oil volume will increase blade angle
to decrease engine RPM. By changing the blade angle, the
governor maintains constant engine RPM (within limits),
independent of the throttle setting.
Reversing Valve
(Controlled oil)
Reversing System
Figure 2-10
Governed
Oil
Low pitch
(Governing)
Reverse
Oil Supply to
reversing valve
Engine
Drain
External Reversing
Valve Assembly
Propeller
OBSOLETE PROPELLER MODELS. SEE COVER PAGE
WARNINGS AND SERVICE BULLETIN HC-SB-61-331