GB407337A - Improvements in or relating to the arrangement of auxiliary dynamo-electric machines employed as generators and starting motors for internal combustion engines - Google Patents

Abstract

407,337. Turning-gear. BEARDMORE & CO., Ltd., W., and BUSH, H. D., 36, Victoria Street, London. Sept. 12, 1932, No. 25346. [Class 7 (v).] Mechanism for transmitting power between an engine and a dynamo adapted to act as a generator and as a starting-motor comprises a differential power-transmission device in the form of a hydraulic torque converter of the reaction type having three sets of vanes or the equivalent ; two sets are connected respectively to the engine and the dynamo and the third, which can constitute a reaction member, can be held stationary or released for automatically effecting the change of ratio when the dynamo has started the engine and the latter speeds up and tends to drive the dynamo. In one form, Fig. 1, an engine gear A meshed with a gear B splined on a shaft C, both gears having helical teeth. The torque converter comprises a set of vanes E keyed to the shaft C, a set G integral with a casing G<1> connected to the rotor D<1> of the dynamo D, and a set H on a sleeve H<1> provided with a free-wheel device K allowing rotation in one direction only. The casing G<1> is formed with a sleeve G<2> having a friction surface for engagement by shoes J<2> actuated by weighted levers J<1> on a sleeve J keyed on the shaft C. When the dynamo D is energized as a starting motor, the clutch J2, G<2> is disengaged and the vanes G rotate with the dynamo rotor ; reverse rotation of the vanes H is prevented by the free-wheel K, and an increased torque is transmitted through the shaft C and gears B, A to the engine at reduced speed. Axial movement of the helical gear B actuates a lever L<5> which bridges contacts M<1>, M<2> to complete the circuit of an auxiliary field winding to provide increased torque. When the engine starts and gains speed, the centrifugal clutch J<1>, G<2> engages and locks the vanes E, G together and the dynamo rotor is driven from the shaft C, rotation of the sleeve H<1> being permitted by the free-wheel K. In modifications : (1) the clutch G<2>, J<2> is replaced by a free-wheel device permitting the shaft C to rotate forwards only with respect to the member H ; (2) instead of the free-wheel K, a brake for preventing reverse rotation of the member H is operated by axial movement of the gear B and collar B<2>, and hand or power mechanism may be used to effect initial engagement of the brake ; (3) the centrifugal clutch is replaced by an externally operated clutch, the inner member of which is moved axially by the collar B<2> to disengage the clutch when the brake is applied ; (4) the gears A, B have straight teeth, one of them being mounted on a screw-threaded shaft ; (5) a greater alteration in the transmission ratio is obtained by using two torque converters arranged in series in such a manner that when the reaction member of one is held stationary, the other is permitted to rotate, and vice versa ; (6) a governor driven through bevel gearing from the shaft C operates a rheostat in the circuit of the dynamo field in order to vary the field strength in accordance with the engine speed ; (7) the centrifugal clutch J2, G2 is replaced by a multiple-disc friction clutch, operated through a link from a lever such as L<5> engaged by the pinion B ; the link acts either through a lever and a sliding collar, or through a piston valve controlling the supply of pressure fluid to the clutch plates ; and (8) the means for altering the speed ratio is operated by a polarized relay reversed by a reversal of the electric current from the dynamo to the battery. In a further form, Fig. 6, the centrifugal clutch is replaced by a hydraulic coupling of the fluid flywheel type with means for automatically removing fluid from the working spaces adjacent to the vanes at low speeds and returning it at increased speeds. The coupling comprises driven vanes T secured by a sleeve T<1> to the dynamo rotor and the outer casing G<1> of the main torque converter. Driving vanes U are secured to the shaft C. Integral with the vanes T is a reservoir V from which extend scoopended tubes W. As the driven vanes slow down, the liquid is scooped into the reservoir, and a very small torque is transmitted; when the speed of the driven vanes increases, the liquid is thrown out centrifugally and a substantial torque is transmitted.