GB489660A - Improvements in or relating to internal combustion engine-electric power units - Google Patents

Abstract

489,660. Fluid-pressure servomotor-control systems. SULZER FRERES SOC. ANON. Feb. 1, 1937, No. 2874. Convention date, Feb. 12, 1936. [Class 135] [Also in Group XXVII] In internal-combustion engine electric power units of the kind having means for setting the speed at which the engine is to operate, and an automatic control for maintaining the engine torque approximately constant for any given speed, interconnecting means are provided between the speed-setting device and the fuelsupply control so that, when the speed setting is altered, the fuel supply is also modified so as to anticipate the action of the automatic control on the fuel supply and avoid the time-lag which would otherwise occur. Fig. 1 shows an engine 1 driving an electric generator 2 supplying motors 3, a governor 9 actuating the fuelsupply control 18 through a servomotor 14 and bell-crank 16. The servomotor 14 also actuates the valve 23 of another servomotor 28 controlling a resistance 26, and thereby the excitation current of the generator 2. The speed is set by a hand wheel 33 adjusting the governor spring 30, and further connected by a lever 41 and link 40 to the floating fulcrum 39 of the bell-crank 16, so as to give the above-described result. The servomotor 14 may be omitted. The fuel control may vary the timing of the suction valve or a spill valve of the fuel pump, or may regulate the point of cut-off of a helical control edge on the plunger, e.g. as described in Specification 475,603, or a rotatable sleeve surrounding the plunger may be adjusted. A lost-motion device may be interposed between the speed setting device 33 and the lever 41 so that adjustment of the fuel control will not occur at speed settings above a certain value. Again, the change in fuel control caused by adjustment of the device 33 may be made to follow a predetermined law by a cam surface inserted between the device 33 and the link 40. Figs. 6 and 7 show a modification in which the hand adjustment regulates the fuel control directly, and this through the interconnecting means adjusts the speed setting. The governor 9 is provided with three springs 77, 78, 79 arranged to come into action successively, and is connected by a lever 80 to the servomotor 28, and to a link 82 adjusting the eccentric fulcra 85 of levers 86 controlling the suction valves 89 of the fuel pumps 88. Levers 87 pivoted to the pump plungers are connected to the levers 86, and also to a rack 90 geared to a shaft 75 which is actuated by the hand adjustment 76. With the parts in the position of minimum speed setting shown in Figs. 6 and 7, a piston 74 bearing on the spring 77 is fully raised, and the other springs are out of action. When the hand wheel 76 is rotated to set a higher speed, the shaft 75 raises the rack 90 to increase the fuel supply and also, by means of a contact 93, to close a circuit 94 of an electric relay 95, which turns a valve 96 to admit pressure above an annular piston 98 and bring into action the second governor spring 78. For a higher speed setting, the circuit 101 of another relay 102 is closed, so as to actuate a valve 103 to supply pressure fluid above the piston 74 and bring into action the third spring 79. A hydraulic governor may replace the centrifugal one. Also, the fuel pump may have two regulating- devices, one actuated by the speed-setting device, and the other by the governor.