Small Engines II
applied load
A resistive force opposing engine forces.
governor system
A system that maintains a desired engine speed regardless of the load applied to the engine.
dither effect
An effect based on the theory that less time is required to accelerate mass that is already in motion
governor droop
The amount of rpm decrease between top no load governed speed and the rpm where power is delivered
governed speed
The speed obtained at the balance point between the forces of the speed-sensing device and the governor spring
hunting
The undesirable quick changing of engine rpm when set at a desired speed
surging
The undesirable slow changing of engine rpm in a cyclical pattern when set at a desired speed
speed-sensing device
a governor system attached through linkage to the throttle plate of the carburetor to sense changes in engine speed
governor spring
a governor system component that pulls the throttle plate toward the wide open throttle (WOT) plate position
governed idle
a governor system function that allows an engine to accept light to moderate loads at idle speed without stalling the engine
electronic governor system
a governor system that used a limited angle torque motor in place of the governor spring and speed-sensing device used in a mechanical governor system
mechanical governor system
a governor system that uses a year assembly that meshes with the camshaft or other engine components to sense and maintain the desired engine speed
parasitic load
any load applied to an engine that is over and above the frictional load of an engine
governed idle spring
governor system component has a low spring rate that offsets some of the force from the speed-sensing device to improve governor sensitivity at low rpm
Governor Blade
movable metal or plastic blade which deflects air from flywheel fins to act as the speed-sensing device of a pneumatic governor system
pneumatic governor system
system which uses force from moving air produced by rotating flywheel fins to sense engine speed
spring rate
the force necessary to stretch the spring one unit of length in
top no-load speed
the top speed setting an engine will achieve without any parasitic load from equipment components
hysteresis
undesirable motion of governor system components caused by engine vibration and governor system functions characteristics