Upon an increase in engine speed, weights 1 of the centrifugal governor move outward and, turning about axes O, compress conical spring 2. This raises valve spool 3 and hydraulic fluid from sleeve 4 is discharged through channel 5 to the engine crankcase. As a result, the propeller pitch increases, increasing the power required to drive the propeller and, consequently, reducing the engine speed. At this, weights 1 turn in the opposite direction, spring 2 shifts spool 3 downward, blocking off fluid discharge to the crankcase, and fixing a definite position of the blades and propeller pitch. Upon a reduction in engine speed, weights 1 move inward, spool 3 is shifted downward, connecting channel 6, to which fluid is delivered under pressure, to the space in sleeve 4 of the propeller. This fluid turns the blades, reducing the pitch and the power required to drive the propeller and, consequently, increasing the engine speed. The required propeller (and engine) speed is set up by regulating conical spring 2. This is done by turning lever 7 which is attached to pinion 8. The pinion meshes with gear rack 9 which regulates the compression of spring 2. Valve 10 serves to by-pass fluid delivered by gear pump 11 when spool 3 is in its neutral and upper positions.
$4267$CHP,Rg$