Upon an increase in speed of the turbine shaft being controlled, the weights of centrifugal governor 1 move outward and its sleeve moves upward. This turns lever 2 about point O, shifting the spool of valve 3 downward. Hydraulic fluid from valve 3 is admitted to the right end of servomotor 4, moving piston 5 to the left, thereby closing the regulating member of the turbine and reducing the shaft speed. At the same time, the rod of piston 5 turns lever 6 about fixed axis D. At this, spindle 7, together with friction wheel 8 and cam 9, is shifted to the right, turning lever 2 about point A to return the spool of valve 3 to its central position. The gear rim of friction plate 10 meshes with gear 11, which rotates continuously with the governor shaft. Friction wheel 8, being displaced from the centre of friction plate 10, rotates on the thread of the spindle and therefore travels axially toward the centre of friction plate 10. This shifts cam 9, linked to wheel 8, shifting the directional valve spool downward to block off fluid delivery. The regulating process continues until friction wheel 8 returns to the centre of friction plate 10, and point O is thereby returned to its initial position. As the speed of the turbine shaft decreases, it reaches its normal value. Piston 5 of the servomotor occupies the position corresponding to the new load on the turbine.
$4240$CHP,Rg$