Patent GB-555630-A (GB)
Title: Improvements in and relating to hydraulic governors
IPC: F02D1/00
Filed: 1942-07-15
Abstract: 555,630. Fluid-pressure servomotor-control systems. WYNDHAM HEWITT, Ltd., GREEN, G. W. A., BUJAK, J., and RUTHERFORD, R. E. July 15, 1942, No. 9842. Addition to 529,760. [Class 135] Various modifications may be made in the hydraulic governor of the parent Specification, the principal modifications being shown diagrammatically in Figs. 1 - 3. The end a of the control plunger is acted on by pressure supplied from the engine-driven pump G<SP>1</SP> through conduits 8, 53, and the end c by pressure supplied through a valve P acted on by a spring R and a conduit 11, and the loading spring 51 acts in a direction tending to shut off the supply of fuel to the engine. The plunger in addition to its longitudinal movement may also be manually turned to vary the leak-off area, grooves 12 in the end c co-operating with ports in the barrel d leading to an annular chamber 13. Ports 63, 64 form an idling orifice controlled by edges 63a, 64a, port 62 is the main leak-off orifice controlled by the edge 62a, a transition port 65 is controlled by the edge 65a, and a permanently open port 66 may be provided. Liquid from the chamber 13 passes through a pipe 31, past an enlargement 24 on the valve P, and through conduits 15, 4 to the suction of the pump G<SP>1</SP>. If the engine is forced to run above the speed for which the manual control is set, the excessive pressure developed by the pump G<SP>1</SP> is relieved through the duct 54 in the valve P. When the pump G<SP>1</SP> is fed from the engine fuel supply, means are provided for enabling the governor to function in the event of failure of the supply. The arrangement comprises a feed pump 71 delivering from a supply tank 70 to the top of an air separator w having a small vent 72 to the tank 70, and a connection x to the fuel injection pump, the reserve of fuel below the connection x being available to feed the pump G<SP>1</SP>. A connection 16 vents air from the governor circuit to the separator. In a constructional form embodying the above-mentioned and other modifications, the main member of the governor casing is bolted to the fuel injection pump P, Fig. 6, the camshaft C of which is geared to the pump G. Liquid for, acting on the control plunge end a passes through a port 53 so sized as to damp flutter of the plunger and that for acting on the end c passes through the valve P, Fig. 5, and port 10. The projection 24 is formed on the spring-urged piston S. The control plunger is turned to vary the leak-off area by means of a yoke m operated from a manually operated speed control shaft and having a screw projecting through a slot n into a keyway o<SP>1</SP> and a lever on the control shaft co-acts with an adjustable maximum speed stop and with an eccentric cam constituting an idling stop adjustable from a remote position. Liquid returning from the annular chamber 13 to the suction side of the pump G<SP>1</SP> passes a constriction formed by a head 32. The governor casing is provided with a scavenge pump 17, the discharge of which joins the return from the separator w to the main fuel supply tank. The fuel injection pump control rod is provided at the end remote from the governor with an adjustable stop 39, Fig. 11, limiting its maximum travel by contact with a pivoted trigger 46 held by a spring 47 in either of its extreme positions. In one position the trigger allows the rod to be moved to give excess fuel for starting from cold, the motion unbalancing the trigger, which is subsequently released and moved to its other end position.