GB194075A - Improvements in or relating to electrical ship propulsion systems - Google Patents

Abstract

194,075. Miller, L., Campbell, J. P., and Metropolitan-Vickers Electrical Co., Ltd. Jan. 19, 1922. Dynamos and motors combined for transmitting power. -Relates to ship propulsion sets comprising internal-combustion engines, alternators, and reversible induction motors, and consists in mechanical arrangements for enabling the starting, reversing and speed regulating switches to be operated bv continuous movement of a single hand-wheel, and for interlocking the switches with the engine fuel controlling handle. The installation described comprises two such sets driving respectively on port and starboard propellers. Each set has a single main hand-wheel 27, Figs. 2, 3, connected through worm gearing 31 to a shaft 30 fitted with a set of cams 32 which actuate the various switches through link-work 34. Fig; 1 shows the circuit connections. Between each alternator 4 and corresponding motor 3 are a generator main switch 7, isolating switches 8, 9, and forward and reverse motor switches 5, 6. Tying switches 25 connect the starboard and port installations so as to drive both motors from one generator when necessary. Rotor short-circuiting switches 11 exclude starting-resistance and inductance 10 from the motor circuits. The generator field windings 12 are connected to an auxiliary supply 13 through circuitbreakers 19, and are variably excited by boosters 16 furnished with rheostats 18. Movement of a controlling hand-wheel from a middle " off " position closes either the forward or reverse motor switch of the corresponding set, according to the direction in which the wheel is turned, and, by continued movement actuates successively the main generator switch, the field switch, the field rheostat, and the rotor short-circuiting switch. The supply of fuel to the engine is controlled by a hand-wheel 35 which is interlocked with the hand-wheel 27 so that the latter cannot be moved from its " off " positions unless the engine is on low speed supply. In order to vary the sequence of operation of the rotor short-circuiting switch when the hand-wheel is turned back in manoeuvring, the operating-cam is designed with a cyclical groove fitted with one-way gates so that the roller is constrained to follow different paths according to the direction in which the handwheel is turned Interlocks are provided between the hand-wheel and the reversing-switches, and between the reversing and the isolating switches. Protection against faults is afforded by arrangements of known kind for tripping the generator field circuit-breakers.