GB666991A - Improvements relating to hydraulically actuated speed governors - Google Patents

Abstract

666,991. Fluid-pressure servomotor-control systems. MASSEY MACHINE CO. Nov. 18, 1948, No. 30039/48. Class 135. In an engine speed governor the engine rotates through a shaft 10 a ported sleeve 15 containing a piston valve 17, fly-weights 20 being pivoted to the sleeve at 22 and having a toggle connection to the valve at 24 so that on an increase in speed the piston is moved downwards against the centralizing spring 55 and the speed-setting spring 60. Pressure fluid from the pump 25 driven from the shaft 10 is supplied via the accumulator 29 to a port 32, and operates the piston 42 via passages 37, 38 and ports 39, 40, controlled by the lands on the valve and exhaust ports 52, 53. The engine shaft also drives at a different speed the rotary valve 90, angularly ported at 91, 92 so that on opening of the ports 39, 40 by the piston valve pressure fluid passes to the cylinder in spurts as the rotating ports in the sleeve and rotary valve come into line. The speed setting through the spring 60 is adjusted from the gear 73 acting through a rack 71 and differential gear 69 pivoted on the sliding rod 63. Movement of the piston adjusts a throttle or fuel control means through the crank 12, and readjusts the piston valve through the lever 80, rack 70 and differential gear 69, the lever fulcrum 84 being adjustable to control the speed droop. In a modification, the piston valve is balanced for lateral pressures by the provision of a stationary sleeve between the rotating sleeve and the housing 14 and the formation of annular grooves in both sleeves. In a further modification, supply passages to the cylinder bye-pass the rotary valve 90 and are connected to ports in the piston valve which are only uncovered when the valve is moved by the application of a sudden load producing a large speed variation, the opening of these ports increasing the number of spurts of pressure fluid. The "rapidity" characteristic of the governor is controlled manually by the opening of the rotary valve 98.