GB190725386A - Improvements in Power Transmission. - Google Patents

Abstract

25,386. Thomas, J. G. P. Nov. 15. Distributing. - Relates to electro - mechanical power transmission systems of the kind in which a prime motor and two dynamo-electric machines are mechanically interconnected through three members of an epicyclic gearing. The prime-mover A is connected to the planet-carrier D, the planet-wheels d, b gearing with sun-wheels g, f connected respectively to the armatures C, B. The field-magnet frames C', B' are stationary. On a hollow shaft E a brake P is arranged, and a clutch Q is adapted to connect the hollow shaft K to the load shaft H. The dynamo-electric machines are series wound or separately excited, and the field strength is varied by a shunt for the winding. The armatures of the machines are electrically connected. At starting, the wheel g is stationary, and the wheel f and armature B are rotating in a weak but increasing field B<1>. The current generated is led to the armature C, which starts the vehicle. As the vehicle gains speed, the field C' is diminished, and the armature B diminishes in speed, and may be held by the brake P. If the ratio of the diameters of the wheels b, f is twice that of the wheels d, g, the armature C is then rotating at half the speed of the shaft A. If the field C<1> is reversed and the brake P released, current is generated in the armature C and drives the armature B in the same direction as the engine shaft A. By increasing the reversed field C', the speed of the armature B may be increased to the speed of the shaft A, so that the whole of the gearing is rotating solidly. The clutch Q may then be engaged so as to give a mechanical drive at the top speed. The brake P may, under these circumstances, be used to retard the vehicle. The direction of motion is-reversed by reversing the field C' and exciting it strongly, and gradually increasing the strength of the field B. During reverse movements, the shaft H may be separated from the gearing and the sun-wheel g held stationary. The machine C may be connected up as a braking-generator, the current developed being dissipated in resistances or employed to drive the motor B against the brake P. In a modification, the prime-mover is connected to the smaller sun-wheel and the machine B to the planet-carrier. The apparatus is described in connexion with a motor vehicle, but is applicable for other purposes, such as winding - gear. In this application, the energy of the descending cage is stored in a flywheel by transmission through the machine C running as a generator and the machine B running as a motor.