Patent GB-190325785-A (GB)
Title: Improvements in Power Transmitting Mechanism.
Inventor: ELIHU THOMSON
Filed: 1903-11-25
Abstract: 25,785. Thomson, E. Nov. 26, A.D. 1902, [date applied for under Patents Act, A.D. 1901]. Void. [Published under Patents Act, A.D. 1901.] Motor road vehicles.-A prime mover, such as a steam or gas engine, water-wheel, or other source of mechanical power, such as an electric motor, is geared to the load through an electrietransmitting-device, comprising generator and motor elements, so that the speed of the object driven and the torque transmitted thereto can be varied This device is applicable to motor road vehicles &c. In the arrangement shown in Fig. 1, the prime mover 1 drives a dynamo armature 2, the field structure 3 of which is free to rotate on the arma ture shaft. A chain 4 transmits rotation from the generator element 3 to the mechanism to be driven. Conveniently, the armature is connected in series with the field windings. By changing the strength of the field, or the amount of current flowing in the armature, or both, the speed of the element 3 can be varied. The current generated is transmitted to a motor, having a fixed field structure 6 and an armature 7, which is coupled directly, or through gearing, to the armature 2, so that the torque exerted by the motor serves to assist the prime mover in driving, The motor may be connected up in shunt or series, but is shown as connected in series. One terminal of the generator field windings and one of the brushes 12 are connected to collector rings 8 on the element 3, the current being taken from these rings by brushes 9 to the motor. A rheostat 10, connected in shunt with the field 6, provides a variable resistance for regulating the counter electromotiveforce of the motor, and consequently varies the current developed in the generator. A switchtripping cam, geared to the rheostat, operates a switch to short-circuit the motor when the rheostat is turned to the 'off' position. In a modification, the generator and motor elements are arranged one within the other. A shaft driven by the prime mover carries a ring upon which the motor and generator armature windings are mounted. The ring is enclosed by the fixed field-magnet structure of the motor, and within the ring is mounted a shaft carrying the generator fieldmagnet structure. This shaft carries a worm driving a differential gear forming part of the driving-mechanism of a motor road vehicle &c., or is otherwise coupled to the mechanism to be driven. Fig. 5 shows an arrangement in which an alternating-current generator and motor are employed. The armature 30 is coupled to the prime mover 28 and is surrounded by the field-magnet structure 31, geared, through a chain &c., to the mechanism to be driven. Leads from the windings of the armature 30 extend through openings in the shaft 38 to the windings of the rotating member 34 of the induction motor. The fixed induced member 35 of the motor has its windings connected to resistances 36, which may be varied by a resistance-changing device 37. The rotating fieldmagnets 31 are energized by direct currents supplied from a storage battery &c. 39. In the arrangement shown in Fig. 6, the armature 42 consolidates both the generator and motor armatures and is surrounded by the induced member 44 of the motor and the rotating field-magnet structure 43 of the generator. The armature 42 is provided with a rectifying commutator 45 for supplying a direct current to the field-magnet windings. The generator field structure transmits motion to the driven mechanism by chain &c. gearing.