GB679576A - Power plant - Google Patents

Abstract

679,576. Driving-gear; power plant; regulating. FELL DEVELOPMENTS, Ltd. Jan. 12, 1951 [Feb. 3, 1950], No. 2886/50. Addition to 628,448. Classes 7(ii) and 7(vi) [Also in Groups XXVI and XXXI] Two compression-ignition internal-combustion engines are used for driving a mechanism of the kind requiring a driving torque which is at a maximum when starting the mechanism from rest and falls steadily with speed increase, e.g. a railway locomotive, by combining their outputs througt epicyclic gearing as follows. Each engine, such as 1a, Fig. 1, of a side-by-side pair drives through a scoop - controlled variable filling fluid coupling 5a and a shaft 6a one sunwheel 8a, Fig. 3 (plan view), of a primary differential gearing 7a or 7b, fast with the planet carriers of which are gears 11a, 11b respectively meshing gears 17a, 17b fast with the sunwheels of a secondary differential gearing 18 the planet carrier of which has rigid therewith a gear 19 delivering power by spur and bevel gearing (not shown), including reversing-gearing, to gears 23 driving the locomotive wheels. Each engine 1a also drives the second sunwheel 9a of its respective primary differential gearing 7a from the respective shaft 6a through a further variable filling fluid coupling 14a. Associated with each sunwheel of each primary differential gearing are one way brakes 15a, 16a, of the kind described in the parent Specification, which prevent backward rotation of the corresponding sunwheel. The scoops of the couplings 5a are operated from the locomotive cab through individual rods such as 25a and the scoops of the couplings 14a are similarly operated through individual rods such as 26a. In operation, on starting, only one coupling 5a is filled, and one engine alone drives through its shaft 6a the corresponding sunwheel 8a so that, the associated coupling 14a being empty, an overall four to one gearing reduction ratio in the epicyclic gearing results. When a suitable speed has been reached, the other engine 1a is correspondingly cut in to give an overall two to one gearing reduction ratio, and, after a further appropriate speed increase, the couplings 14a are finally filled for a direct drive. Either of the couplings 5a may be replaced by a constantly filled fluid coupling and either of the couplings 14a by a clutch and a constantly filled fluid coupling in series, or any of the couplings by an equivalent torque transmitter such as a magnetic clutch. The engines 1a are supercharged by a blower 2 driven by an auxiliary compression-ignition I.C. engine 3, which is governed to a constant speed such that, up to a predetermined speed of each engine 1a, it is supercharged at a maximum pressure set by a blow-off valve 44, and, above this predetermined speed, the supercharging pressure decreases as the speed of the engine 1a increases. Each engine 1a has a fuel injection pump governing and regulating mechanism which is as described with reference to Fig. 1 of Specification 661,280 excepting that the interconnection with the scoop control of the corresponding coupling 5a may be mechanical. The manual control levers of both mechanisms are operated from a single lever 43 in the locomotive cab. The scoop controls of the coupling 14a may be actuated separately or together in accordance with locomotive or engine speed, and the couplings themselves may be other than co-axial with the couplings 5a and driven through spur or chain gearing. Two or more locomotives each driven by a power plant according to the invention may be coupled in series to obtain a desired tractive effort/speed relationship. According to the Provisional Specification, flexible couplings may be interposed between the engines 1a and couplings, 5a, the couplings 14a may be driven directly from the shaft 6a by spur or chain gearing, and the controls for the engines 1a and couplings 5a may be as described in the parent Specification or in Specification 641,873.