GB1231266A - - Google Patents

Abstract

1,231,266. Fluid-pressure servomotor systems. CKD PRAHA, OBOROVY PODNIK. June 27, 1968 [July 1, 1967, Oct.31 1967, June 5,1968], No.30701/68. Heading G3P. A governor for compression ignition engines, comprises centrifugal weights 1 loaded by a spring 2, actuating a slide valve 3 distributing oil to a piston and cylinder 6, 5 which by rectilinear motion controls a lever 33 on a shaft 34 of a fuel metering device in a injection pump, the piston 6 having at least one oblique control surface 7 co-operating with an overflow bore 11 in the wall of the cylinder 5, and being rotatively mounted within the cylinder, and connected to a speed control lever 28 through a linkage 22, 27, and with the shaft 34. The valve 3 is connected with the cylinder 5 via an overpressure duct 8 and a pressure duct 9 connecting, respectively, with the upper and lower parts of the cylinder to actuate the differential piston 6 which has a larger upper face. The piston 6 has a plunger 14 in a cylinder which connects with a cylinder of a compensating piston 16 communicating with the valve 3, and a bleed outlet controlled by a needle valve 18. The piston 6 is rotatable by a fuel lever 20. In operation, to start the engine, the speed lever 28 is set to increase the loading of the spring 2, and the fuel lever 20 is rotated to a starting fuel charge defined by the height of the surface 7 above the bore 11, and an oil pump connected with inlet 12 is put into action. Oil is passed to both sides of the piston 6 via passages 8 and 9, and the movement of piston 6 is controlled by the weights 1 and valve 3 until the pressure above the piston escapes through the bore 11 and the engine output is controlled at the setting of the fuel lever 20. When the engine has started, the speed lever 28 is set to the required engine speed, and when the forces acting on the weights 1 are balanced by the spring 2, the valve 3 closes duct 8. If the fuel charge is insufficient for the load the engine speed drops, and valve 3 uncovers duct 8 to cause piston 6 to move down and increase the fuel charge until the engine speed is restored. In Figs. 2, 3 and 4 (not shown), a piston (6) has four oblique surfaces (7) forming two opposite charging chambers (35) connected through ports (37), and two opposite outlet chambers (36) connected with the outlet (11) via ports (38). In Figs. 5 to 8 (not shown), the fuel lever (20) rotates the cylinder (5) with respect to the piston(6), and the speed lever (28) rotates the piston (6) via rods (52), (53) and bevel gears (48), (49) as well as adjusting the governor spring (2) via gears (57), (57<SP>1</SP> ) and levers (58), (59). Ports (39) from the charging chambers 35, and ports (11) from the outlet chambers (36) connect with opposite sides of a rotary piston motor (43) to actuate a rheostat (47) in the field windings of a diesel-electric generator. In Fig. 10 (not shown), a cam (68) is interposed in the linkage between the speed lever (28) and the rotatable piston(6).