GB185409A - Improvements in control mechanism for electric ship propulsion and like systems - Google Patents

Abstract

185,409. Metropolitan - Vickers Electrical Co., Ltd., (Assignees of MacNeill, J. B., Bakken, A. H., and Tucker, C. A.). Sept. 1, 1921, [Convention date]. Dynamos and motors combined for transmitting power. - Installations comprising turbines, dynamo - electric generators, and motors, for ship-propulsion and other purposes in which the control switches are operated by a number of separate handlevers, are provided with groups of mechanical interlocks to prevent incorrect sequence in manipulating the levers for starting, speed control, stopping, reversing, &c. Generator field switch levers are locked by fluid pressure in cylinders communicating with turbine speed controllers, in order to prevent the opening of the field switches if the turbines are running above a certain speed. The invention is described in connection with an installation arranged as shown in Fig. 4, and comprising two turbine-driven generators 1, 2 and four motors 3, 4 driving four screw propellers. The control gear consists of generator field-switches 5, 6, motor pole-changing switches 9, 10 corresponding respectively to 36-pole and 24-pole motor fields, forward and reverse switches 11<a>, 11<b>, liquid rheostats 12 operated by valves 12<a>, motor-secondary switches 13, separate generator circuit-breakers 14, 15, and circuit-breakers 16 for tying all the motors to one generator when required. Figs. 1 and 1<a> show the disposition of the hand-levers and interlocks for two motors normally fed by separate generators, black rectangles representing the levers in their open positions. A group of interlocks shown in Fig. 1, consisting of a number of bent levers 27, 38, rocked by longitudinal movements of bars 24, 37, ensure that the generator field switch hand-levers 88, 89 are closed after the reversing and pole-changing levers, and before the rhecstat valve and motor-secondary levers. The bars 24, 37 are disposed as shown in Fig. 2 to work separately while the motors are being fed from different generators, but are locked together when all the motors are thrown on the same generator. A second group of interlocks, shown in Fig. 1<a>, consisting of a number of longitudinally slidable rods 132, 133, the extremities of which are adapted to move into and out of the paths of the switch hand-levers, ensure that the generator circuit-breakers, the pole-changing switches, and the reversing switches are closed successively. Interlocks of the second group also prevent the generators from being accidentally paralleled when the tying circuit-breakers are closed. After the generator field switches have been closed, the hand-levers are permitted by a lost-motion device, irrespective of interlocks, to be moved back far enough to insert resistance for accelerating. The Specification fully describes the interlocking functions in the sequences of operations for starting, running up to full speed on the initial pole setting, changing to economical pole setting, reversing, and stopping.