Patent GB-1164661-A (GB)
Title: Electrical Machine for Disc-Type Construction
IPC: H02K19/24
Filed: 1966-07-29
Abstract: 1,164,661. Alternators; motor-generators. LLOYD DYNAMOWERKE G.m.b.H. 29 July, 1966 [31 July, 1965], No. 34101/66. Heading H2A. A planar air-gap disc-type machine has at least five component discs (three stator and two rotor, or vice versa, arranged alternately), the magnetic flux permeates all the interior discs at least once in each axial direction, and a magnetic return path is formed only by the end component discs. As shown in Fig. 1, two rotor discs 33, 34, without windings are provided, each including a non-magnetic separating layer 44, Fig. 3, and having on each face two sets of teeth 49 and slots 50, relatively staggered. Each end stator disc is laminated in the air-gap region but at the outer side is of solid material to form the magnetic return path 40; each end disc has a space 46, Fig. 2, for a D.C. exciting coil 35 or 36, Fig. 1, and has an A.C. output winding 47. The centre disc 32 is wholly laminated, and has one exciting winding 37 and two output windings. The rotor teeth and slots may be continuous instead of staggered (Fig. 5, not shown) in which case the radially-outer parts of the output winding (i.e. the parts crossing the annular region 39, Fig. 2) are circumferentially staggered by one slot (Fig. 4, not shown). Each winding 47 may be designed for a different voltage from the others, and each of the four rotor-part faces may have tooth numbers selected to produce a different frequency; thus the generator shown may deliver four different voltages at four different frequencies. In Fig. 9, there are again two rotor discs 33, 34 but in this case the excitation coils 63 are provided in the rotor discs and are fed by slip rings, not shown. Cooling channels 66, cooling inlets 68, cooling passages 70 to 72, and baffles 73 are provided for air ventilation; an electricallyconducting pipe 74 for liquid coolant serves also as a damping winding. In Fig. 11, three rotor discs constitute the outermost and innermost members: they are solid, without non-magnetic separating layers, and have teeth and slots at their airgap faces. The stator discs 157, 158 have each one exciting coil and two output windings. In Figs. 6 and 7 (not shown), a modification of Fig. 1, a single, larger, exciting coil is provided, and is accommodated in the centre stator disc. The laminated portions of the stator discs are each divided by the output winding into a number of separate cores which may be laminated or consist of ferrite material. In Fig. 8 (not shown), (a different modification of Fig. 1), a single, central, exciting coil is again provided; the end stator discs each have a non-magnetic separating layer; and the rotor discs are each laminated, except for the non- magnetic separating layer, and have an outer securing ring. The laminations may be a wound strip. Fig. 10 (not shown), is a modification of Fig. 1, but has rotor discs without non-magnetic layers. Nearly all the cooling features of Fig. 9 are provided. Fig. 16 is a machine combining motor and generator functions. Thus, three-phase A.C. is supplied to windings 114 in an innermost stator disc 113. The windings 114 lie in radial slots in the faces of the disc 113 and their end connections lead obliquely from one face to the other at the outer circumference (Figs. 19, 20, not shown). Each rotor disc has four interdigitated poles formed in the surface which faces the innermost stator disc, all these parts forming a synchronous motor assembly. At each end of the machine a generator assembly is formed by the (outer) toothed and slotted face of a rotor disc and by a stator disc 30 or 31 having a D.C. exciting coil 35 or 36 and an A.C. output winding 47. Each rotor disc includes a non-magnetic separating layer as before. Fig. 21 (not shown) is a modification of Fig. 16, where the rotors are inverted and the functions of the stator portions are interchanged, so that each end of the machine performs a motor function and the centre a generator function; the central stator disc has a single D.C. exciting coil. In the generator of Figs. 22, 23 (not shown), two rotor discs are provided, each having two D.C. exciting coils (each in the form of a closed semi-circle), embedded in each face, the coils being covered by pole shoes, around which damping rings may be located. All three stator discs are laminated throughout; the end discs have one output winding each, and the centre disc, two. In Figs. 24, 25 (not shown), the rotor discs for this machine each have a single annular array of twelve exciting coils, each surrounding a salient pole and covered by a pole shoe. The other face of the disc has radial recesses 140 in line with the spaces between the salient poles.