A GOVERXOR FOR TET.EPHOXE DIALS 



1279 



speed curves of both types of governors. This probably results from the 

 shock and grabbing when the friction studs first touch the case and con- 

 tinues initil the forces tending to move the weights outward increase to a 

 value sufficient to hold them against the case for governing. 



That part of the experimental curve, during which governing actually 

 occiirs at rated speed is relatively smooth through full run-down. Both 

 the fly-bar and new drive-bar governors exhibit excellent speed regula- 

 tion. The waves present on the trace do not necessarily indicate hunting 

 or ^'ibration since the variations in speed which appear are actually 

 smaller in magnitude than the degree of accuracy present in measiu'ing 

 the experimental photographic trace. 



RUN-DOWN 



Fig. 7 — Schematic of fly-bar governor. 



Fn — Normal force of case acting on studs 



Fs — Force exerted by spring when studs touch case 



Fm — Centrifugal force acting at center of gravity of each weight 



IX — Coefficient of friction 

 Zo — Moment of enertia of the governor about center shaft 



CO — Angular velocity of governor 



wo — Critical angular velocity at which studs just touch the case 

 m — Mass of each weight 

 Co — Radius to the center of gravity of each weight 



r — Radius of governor case 



a — Stud angle 

 Neg. Rotation — Run down of governor 



