Important terminology in Governor

Governor - The function of the governor is to adjust the supply of fuel according to the load require ments so as to keep the speed at various loads, as close to the mean speed as possible over a long range of working of the engines.

There are some general terms used in governors that describe qualities of the governors.

Heights of Governor: It is the vertical distance between the center of the governor balls and the point of intersection between the upper arms on the axis of the spindle. It is generally denoted by h.

Equilibrium Speed : The speed at which the governor balls the arms etc. are in complete equilibrium and the sleeve does not tend to move upward or downward is called the equilibrium speed.

Sleeve Lift : The vertical distance the sleeve travels due to change in the equilibrium speed is called the sleeve lift. The vertical downward travel may be termed as a negative lift.

Effort and Power of a Governor : A governor running at a constant speed is in equilibrium and the resultant force acting on the sleeve is zero. If the speed of the governor increases there is force on the sleeve which tends to lift it. This force will gradually go on decreasing till the governor starts rotating in equilibrium at the new position of rotation. The mean force acting on the sleeve for a given change of speed or lift of the sleeve is known as the governor effort.

Controlling Force : The force acting radially inward upon the rotating balls to counteract its centrifugal force is called the controlling force. It is provided by weight on the sleeve or compressed spring.

Isochronism : This is an extreme case of sensitiveness, when the equilibrium speed is constant for all radii of rotation of the balls within the working range. the governor is said to be in isochronism. This means that the difference between the maximum and minimum equilibrium speed is zero and the sensitiveness shall be infinite.

Hunting : The phenomenon of continuous fluctuation of the engine speed above and below the mean speed is termed as hunting. This occurs in over-sensitive or isochronous governors.

Sensitiveness : A governor is said to be sensitive if its change of speeds from no load to full load may be as small a fraction of the mean equilibrium speed as possible and the corresponding sleeve lift may be as large as possible. 


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