GB760656A - Improvements in or relating to speed responsive governor - Google Patents

Abstract

760,656. Fluid-pressure servomotor-control systems. GARRETT CORPORATION. Oct. 27, 1954 [Nov. 9, 1953], No. 30997/54. Class 135. A speed-responsive governor comprises a fixed housing containing a rotor driven by mechanism to be governed, a pressure fluid inlet to the interior of the housing, a centrifugally operated valve in the rotor controlling an output pressure which is applied to means for controlling the speed of the governed mechanism, and a pressure-responsive element interconnecting and sealing the centrifugallyresponsive element with the rotor and subject to the pressure difference across the valve. In an embodiment the rotor 24 is mounted in bearings 20, 21 and carries a spring-biased plunger 29 which has at its upper end a closure surface 49 co-acting with a fixed element 50. Pneumatic pressure, after passing through a restriction 18, enters the casing 10 and passes through openings 51 in the fixed member 50 to a space where it acts on a diaphragm 46 in a direction opposing the spring 31 and assisting the centrifugal force on the member 29. When a predetermined speed is reached the valve opens to allow escape of air through passages 52, 41, 42, 43, thereby lowering the pressure in the casing 10 and consequently in a passage 19 which leads to pneumatic mechanism for controlling the speed of the governed apparatus. To compensate for the variation in centrifugal force on the member 29 due to its displacement relative to the axis of the rotor the air on the outlet side of the valve has access to the lower surface of the diaphragm. In a modification, the valve member is arranged to be normally open and to close in response to increase of speed.