A GOVERNOR FOR TELEPHOXE DIALS 1293 



This expression must be satisfied if the governor is to operate free of 

 chatter. 



By substituting the constants for the fly-bar governor, in Table III, 

 we have for this governor operating in the vertical plane 



^QrQfin^ < 7,5 00(0.390 - (0.25) (0.361)) 



^•^^^^^^ - 2(1 18) (0.25) (1.092) 



or 



3,820 dyne-cm g 2,790 dyne-cm. 



Since the equation is not satisfied instability should be present and 

 governors of this fl\'-bar de.sign do chatter loudly when operating in the 

 vertical plane. 



The chatter equation for the fly-bar governor indicates that by adjust- 

 ing the design constants, one can eliminate the instability effect. This is 

 true. A set of values could be used which would result in a fly-bar gover- 

 nor which operates free of chatter. Unfortunately such a governor would 

 also have reduced ability to govern. The relationship between chatter 

 and governing is explained as follows.^! 



The equations which define changes in governor speed with respect to 

 changes in friction and torque for the fly -bar governor 



^ = ^^ 

 dy. 2uMfx^ 



and 



dco _ 1 (d — fic) 

 dG ~ 2 Mmco 



and the chatter equation, (19), show that operation without chatter and 

 good speed regulation are totally incompatible. Those terms in the 

 equations which should be small for good speed regulation; i.e., torque G 

 and stud location d and c, should be large to avoid chattering of the 

 governor. Those temis which should be large for good speed regulation; 

 i.e., case radius r, friction n, and the distance from the pivot to the 

 center of gravity I, must be small for no chatter. As the theoretical 

 analysis indicates there is no term in the fly-bar governor chatter equa- 

 tion which can be operated on to eliminate chatter without impairing 

 regulation of speed. 



A similar analysis, given in Appendix IV, shows the chatter equation 

 for the new drive-bar governor to be 



< G(d - MC - yrj/e) (20) 



2rti€smfi 



