Patent GB-166181-A (GB)
Title: Improvements in or relating to dynamo-electric power transmission systems
IPC: H02K51/00
Filed: 1918-02-05
Abstract: 166,181. Neuland, A. H. Feb. 5, 1918. Machines with two or more armatures; electromagnetic clutches; cores, yokes, and carcase structures; coils; casings; dynamos and motors, cooling and ventilating; mounting rotors.-An electric power transmission system, one element of which may operate as an engine starter, comprises a dynamo-electric machine having two stationary field magnets and two independent rotary armatures one of which is driven by the prime-mover and operates inductively and electrically upon the other which is coupled to the load shaft. The poles of the two sets of field magnets are in staggered relationship and the generator field is provided with a shunt winding in series with a battery and an adjustable reverse winding, while the motor field is provided with an adjustable series winding. The generator is provided with an auxiliary brush between which and the positive brush of the generator the battery is placed, while a resistance is adapted to be inserted in the load circuit when the battery current reaches a predetermined value. The axes of the armature windings are parallel to the axes of the armatures while the windings are placed in the slots of laminated pole-pieces secured radially to the peripheries of rotating armature discs by bolts. The machine is partly enclosed at the top and bottom and is ventilated by two air collectors and by providing the peripheries of the armatures with vanes. The machine M, Fig. 1, is provided with a field yoke 4 having projecting pole-pieces 6 carrying a shunt winding 38 and a series winding 37 and a field yoke 5 having similar pole-pieces 7 carrying a series winding 36. The pole-pieces 6 and 7 are in staggered relationship and the yokes 4 and 5 are provided at the top and bottom with grooves adapted to receive cover plates 34 and 35. The armature discs 8 and 9 are nrovided with twentythree and twenty-five radial holes respectively, of square section at their outer ends. Metal bolts 10 projecting beyond the peripheries of the discs 8 and 9 are forced into the holes and thread polar laminations 11, Figs. 1 and 3. The laminations 11 are provided with slots 12 adapted to receive the armature windings 15, while spaces 13 between adjacent sets of laminations form additional slots, thereby forming twice as many slots as bolts 10. The laminations 11 and bolts 10 are held in position by non-magnetic rings 14. Each armature winding 15, Figs. 1 and 5, is arranged so that it crosses the armature transversely in order that one part lies in slots on one side and another part in slots on the opposite side of the armature, and the ends of the armature windings are connected to commutators 16 and 17 respectively. The commutators are provided with stationary 'brushes 18 and 19. The armature disc 8 is carried by an internally tapered and keyed nut 20 mounted upon a tapered extension 21 of the crank shaft 2. The hub 20 is drawn upon the extension 21 by providing them with right and left-handed screw threads engaged by similar threads in a nut 22. The driven or load shaft 3 is journaled in the hub 20 by a bearing 24 to maintain the armatures in correct axial relationship, while an intermediate bearing 25 may be provided. The field yokes 4 and 5 are spaced apart and secured to the engine casing by four shouldered bolts 27 and an auxiliary support consisting of a arm 29 and a rib 30 may be provided. The machine is ventilated by leaving the sides of the casing open and by providing two air collectors 31, 32 and fan vanes 33 on the peripheries of the armatures. Under nnrmal forward running conditions the switch 47, Fig. 4, is open and the switch 48 closed in the position shown. Since the plane of the brushes 19 is at right angles to that of the brushes 18 a motor action occurs between the armatures A and B, and since these armatures are in close inductive relationship to each other and their electromotive forces are out of phase they act as fields for one another. With a constant load on the driven shaft an increased engine speed increases the strength of the current in the field winding 37 and causes a greater increase of speed in the armature B connected to the load shaft, while a decrease of engine speed causes a greater decrease of speed of the load shaft. To increase the torque on the load shaft the strength of the current in the field winding 37 is increased by inserting a resistance 41 in circuit with the field winding 37 and by opening the throttle valve of the engine to increase its speed. A further control of the speed and torque of the load shaft 3 is obtained by placing a resistance 42 in the circuit of the field winding 36. The shunt field winding 38 of the armature A is normally in series with the battery 39. When the current in this circuit becomes abnormal, a switch 44, controlled by a current relay 45, is opened to place the battery 39 in series with a resistance 46 across a brush 18 and an auxiliary brush 43, while the winding 38 is connected across the brush 43 and the other brush 18 of the armature A. To reverse the rotation of the load shaft the switch 48 is moved to its other position. To start the engine, the switch 47 is closed when the armature A and its field operate as a motor on the battery 39.