GB806747A - Hydraulic speed-responsive governors - Google Patents

Abstract

806,747. Fluid-pressure servomotor-control systems. LUCAS (INDUSTRIES) Ltd., J. June 4, 1956 [June 13, 1955]. Class 135. An hydraulic speed-responsive device comprises a body a having a chamber b therein with an outlet z, a rotary body e contained in the chamber and having a passage h in communication with an inlet c in the body and a centrifugally operated valve s carried by the rotary body for controlling the rate of flow of liquid from the passage h in to the chamber b. The rotary body consists of a disc c secured to an engine-driven shaft f. Attached to the disc e is another disc n having a recess flanked on one side by a diaphragm o. The recess is in communication with the passage h by means of a small orifice q. A centrifugal mass t containing a valve closure member s is attached to a T-shaped arm u secured to the disc e by spring hinge blades v. The arm u is also attached to the diaphragm o by a stem x. A weight y is mounted on the disc e to balance the centrifugal mass t. At low speeds motive fluid from an engine-driven pump passes through passage c, a restriction d, passages m, i and h and acts on the diaphragm o, thereby holding the valve closure member s away from the outlet r, allowing fluid to flow freely from passage h into the chamber b. With increasing speed the mass t progressively moves the closure member s towards the outlet r causing an increase in pressure in the passages downstream of the orifice d. These pressure variations are sensed by a diaphragm 6 which acts on a hinged valve 10 controlling a vent 11 from a cylinder 12. The cylinder contains a piston 13 acted on by motive fluid pressure upstream of the orifice d, through a passage 16. A restricted orifice 17 in the piston communicates between both ends of the cylinder. Movement of the piston to the right is controlled by the vent 11. The rod 14 attached to the piston controls a variable output fuel pump or a throttle or by-pass in the fuel supply line to the engine. The governor may also be employed for varying the adjustment of guide vanes in a turbine-type air compressor in response to variations of speed of an associated prime mover.