Patent GB-598042-A (GB)
Title: Improvements in or relating to power units for locomotives
IPC: B61C9/14
Filed: 1945-08-29
Abstract: 598,042. Internal-combustion engine locomotives. FELL, L. F. R. Aug. 29, 1945, No. 22303. [Classes 79 (i) and 79 (v)] [Also in Group XXVII] The main internal-combustion engine of a locomotive has its fuel supply automatically varied with variations in the air supply, air being supplied from a blower driven by an auxiliary internal-combustion engine, the latter being controlled to vary the output of the blower whereby the power developed by the main engine is maintained substantially constant throughout its running speed range and the engine torque diminishes as the speed increases within such range, the main engine being connected to the driving wheels through a fluid coupling whose effective range corresponds to the operating range of the main engine, slipping occurring at speeds below such range. By this means the need of a change speed gear box or the equivalent is eliminated. The fuel supply and ignition timing (or injection timing in the case of a compression ignition engine) of the main engine is preferably varied automatically in accordance with the output of the blower, or in accordance with main engine speed. One auxiliary engine and blower may supply the air for two main engines, each of which is connected through a fluid coupling to a differential gear and the driving axle; or two auxiliary engines and four main engines may be employed, the main engines being coupled in pairs as above, and the drive from each pair being associated in a further differential, from which the driving axle is driven. The fluid couplings are designed so that their effective operating range corresponds to the operating range of the main engines, and each coupling may be provided with braking means which is interconnected with the throttle of its associated engine so that the brake is applied to stop transmission of torque when the engine is idling. The braking means and throttle valve of each main engine may be operated hydraulically by oil from the lubricating system of the main engine, which has the advantage that on failure of the engine or of its lubricating system, such engine is throttled and its fluid coupling braked automatically. Fig. 1 shows an auxiliary engine 11 driving a blower 12 supplying air through the duct 13 to the main engine 10. The latter drives a fluid coupling 16, shaft 19, reversing gear 20 and driving axle 22. In Fig. 3, the auxiliary engine 11 and blower 12 supplies two main engines 10, each driving a fluid coupling 16 whose output shaft 17 is provided with brake drum 26 and brake 28, the two drives being associated by a differential 23 to drive the shaft 19. The brakes 28 are connected to pistons 31 working in cylinders 30 and are biassed by springs 29 to remain on, as at 28b; the throttle valves 25 are similarly connected to pistons 36 working in cylinder 35 and biassed by springs 34 to remain closed, as at 25b. The engine 10a supplies oil under pressure through the pipe 33a, and control valve 32a to the cylinders 35a, 30a, whereby the pistons are raised against the action of the springs, the throttle valve 25a is opened and the brake 28a released, whereby the power is transmitted from the engine. The control valve 32b on the other hand, in the position shown, puts the cylinders 30b, 35b into communication with the vent pipe 40b, and with the throttle valve 25b closed and brake 28b applied, the engine 10b idles and transmits no power. The two control valves 32a, 32b are interconnected by rod 38 and operated by handle 39 so that either or both of the main engines may be used. A mechanical overload cut-out may be associated with each fluid coupling, operated by a centrifugal governor driven by the planet carrier of a differential gear, the two input shafts of which are geared respectively to the driving and driven members of the fluid coupling; such overload cut-out is connected to the hand lever 39 to bias it towards either of its positions in which one of the main engines is inoperative the tendency being resisted manually by the driver. A free-wheel drive may be provided between each fluid coupling and its differential gear, to permit of coasting and to avoid damage in the event of engine seizure.