AU606234B2 - Dual stator generator - Google Patents

Description

~17 J AUSTRALIA,;- PATENTS ACT 1952 606234 P/OO/011 Form COMPLETE SPECIFICATION FIRST AMENDMENT FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: 00o o 0 0 0 00 o Complete Specification-Lodged: o oo Accepted: 0 o 00 Lapsed: o° Published: o 00 ooo Priority: 00 0 I'ihi do:.ument contains the I ai,-;i;dmsntls made under Section 49 and is correct for printing.

Related Art: o o u 60 0 o Name of Applicant: 0 0 000oao TO BE COMPLETED BY APPLICANT PAUL TEPLOW 000000 0 0 Address of Applicant: o e o Actual Inventor: Address for Service: 40 SECOND AVENUE, PALM BEACH, Qld. 4221.

PAUL TEPLOW 40 SECOND AVENUE, PALM BEACH, Q1d. 4221.

Complete Specification for the invention entitled: "DUAL STATOR GENERATOR" The f ~4*1 tement is a full description of this invention, including the best method of performing it known SN T cri is to be typed in double spacing, pica type face, in an area not exceeding 250 mm in depth and 160 mm in dth, on tough white paper of good quality and it is to be inserted inside this form.

14599/7 Printed by C. J. THOMPSON, Commonwealth Government Printer, Canberra THE COMMISSIONER OF PATENTS.

(IMPORTANT Cross out inapplicable words in the above Form.) The Invention is described in the following statement: It is just over one hundred years since Lucien Gaulard and John Dixon Gibbs in Europe and William Stanley and Nikola Tesla in U.S.A. have introduced into wide commercial practice the alternate current electric generators and motors. From that time on, A.C. D.C. generators and motors invaded all areas of mankind activities and electricity became the lifeline of our modern civilization take it away and the whole world will stand still! In fact, electricity went into our sub-consciousness and we live with it day and night, without being aware what it is and where it comes fromn only when we haven't got it we panic! Besides the main original use of electricity for lighting and power, in the second half of this century, its application had spread to so many a new areas of human endeavour that the whole existence of modern civilization 0o is unthinkable without this medium of energy supply. The initial use of 0:0 °electricity in telephone, radio and television gave later an unusual impulse to development of electronics with invention of semi-conductors, micro-chips, computers and a host of automated robots which revolutionised ,400 all areas of industrial technologies, science, medicine, education and even the established homelife pattern.

At the same time, the traditional electricity generating equipment itself went through comparatively modest changes, related mainly to improving efficiency, increasing the size and output capacity on one hand O 00 and miniaturization of components, on the other. These improvements, however, have not eliminated some inherent negative features of the basic electricity generating machines, in particular the large, slow-speed synchronous alternators.

This invention, as described in the following Clauses and presented on diagrammatic drawings, is not intended to create some new electrical phenomenon in the generating equipment, but related only to a new PL1--- arrangement of magnets, whether electro-magnets or the permanent, in 7 relation to stator windings.

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to The accompanying drawings are listed below as follows: Fig. 1 General arrangement of conventional alternator.

1A Alternator with new magnet arrangement without external stator case.

2 )Axial section through dual stator generator.

2) 3 Stator winding slots -front elevation.

4 Rotor side elevation.

Rotor magnet mounting -detail.

6 Rotor fan cooling arrangement.

7 Stator, back elevation.

8 Part 1 and 2: Multi-state generator arrangement.

Analysing the construction of a conventional slow-speed, large diameter, A.C. generator with multiple sets of electra-magnets, its imperfect nature becomes apparent because of the inherent property of dual polarity of any electro or permanent magnets.

Unfortunately, we cannot make the magnets with one pole only, as they always have both South and North polarity, whether we want it or not.

When the magnets are fixed to the generator fly-wheel in sequential order, S-N, N-S polarity, it is obvious that only one pole at any moment produces the actual current in stator windings, while the opposite pole magnetic flux is, so to say, an "idling" flux and is "unproductive", because it is removed from the direct influence on stator windings. This so called "parasitic" magnetic flux could not be eliminated by any known means and is "twasted", and is accepted as an unavoidable "evil". That is an evil indeed, becauge it produces unnecessary heat, causes "stray" Eddy currents and accentuates the phenomonon of "hysterises". In order to minimize these negative tr~aits, the conventicnal magnetic iron core of electro-magnets and stators are usually made of special soft, low carbon steel in thin sheets, insulated from each other by special varnish, then pressed together and riveted or banded as required.

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To resolve these problems, it is necessary to position the magnets on a fly-wheel as it is shown on the sketch, Fig. IA where the magnet S-N or N-S polarity axis is parallel with the rotor axis of rotation and the stator windings are at right angle to the magnets. As the magnets have two poles, it naturally follows that the generator shall have also two stator windings to face each magnet pole.

Diagrammatically this concept is shown on Fig. 2, where two stator frames 1, with side buttresses 2, form a solid stationary support base on foot plate 3, or other substantial foundation. These end frames of non-magnetic cast iron or similar materials are erected true vertical and parallel to each other a certain design distance apart Fig. 2.

D The end frames carry on their opposing planes near the periphery, o e o ring-shaped magnetic iron stator ring. 4, with radial slots 5, to a accommodate the stator windings which terminate in collector cables 6, oor on cable trays 7 below rotor 8, see Fig. 2 and 3.

The stator end frames have extended hubs 9, with bores and bearing linings 10, through which passes the generator rotor shaft 11, of prime mover 12, mounted on a common base plate or separate foundation, see Fig. 2.

This prime mover shaft carries a rotor 8 between said stator 0, ,windings which in this case, is shown to be made of 2 (two) disc-like round plates 13, on common hub 14, so that the rotor firmly and a* t precisely located true and parallel between stator windings, being secured on the shaft by stop bolts, keys or other means 15, see Fig. 2 and 2A.

The rotor could be fabricated of cast iron, aluminium or other non-magnetic materials with end plates being welded by internal angular or round tie bars.

On their periphery, the rotor plates have equally spaced radial slots 16, corresponding to the number and size of magnets 17, as shown on Fig. 4 and 5. Both rotor plates carry external non-magnetic angular rings having angle upper flat level with magnet slots bottom see Fig. r o .4/

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I 1 I 4 The magnet induction coil length shall match the gap between rotor end plates, while the iron core shall extend to the edge of angle flange to allow for fitting of magnet end piece 18, see Fig. 4 and The magnet core and end piece shall be drilled through to match flange mounting holes to take fixing bolts 19. These bolts shall withstand considerable centrifugal and lateral forces and have to be sized with the maximum safety factor in actual manufacturing.

Alternatively, the rotor could be cast in one piece, or 2 halves bolted together, in a manner similar to conventional generators, provided that its design shall allow for a convenient postioning and fixing of electro or permanent magnets, in such a way that each magnet could be removed separately from its "nest" without interference with adjacent magnets.

The magnet cores and the end-plates shall be made from a low carbon soft iron, but not necessarily laminated, but rather a solid bars of a suitable shape to match the form of magnet windings which could be-wound from insulated wire or bars.

The gap between magnets and stator windings shall be as minimal as practically possible.

With the rotary motion of prime mover 12, this type of generator can supply either direct or alternate current according to the induction power connections to magnet coils. When the coils are connected in consequent order from opposite ends, the resulting output will be A.C. with magnets polarity S-N-S-N. Otherwise, if the coils are connected to one induction cable on one end and the other end, to another, it will generate D.C. output with plus on one stator and minus on the other.

For a single stage A.C. generator the induction power to magnets can be supplied from a small D.C. unit of the said dual stator construction mounted on free end of main shaft 20, see Fig. 2 and 2A from which -4% 00 0 0 00O o o 00 00 0 000 0 00 00 0 0 00 0 00 00 0 000 0 00 0 0 40 0 0o 00 0000 0 04 00 4 0 1 0 444' 41 the current is fed to rotor magnets through a set of brushes 21, mounted on induction unit support and 2 slip rings 22, on main shaft 11, see Fig. 2 and 2A.

For a D.C. generator the induction current could be taken from the main supply cables 6, through a set of brushes and slip rings via a power regulator (not shown). The induction current cables have to be placed in 2 shaft slots 23, see detail on Fig. 2. Where this grooved shaft passes through bearings in stator hubs these sections shall have well machined sheath sleeves 24, see Fig. 2 from good quality hardened steel and provided with adequate automatic lubrication. The induction current cables shall emerge from shaft slots on external face of each rotor plate and connected to distributor cables 25, run in concentric rings under the magnets with individual feed wires to each coil according to electrical current required, as described in the text above, see Fig. 4.

Having in mind this more rational and efficient generator, we still face the problem of heat dissipation from stator windings and rotor magnet coils. In any generator which has a limited number of magnets with measurable distance between them, the cooling problem may not arise as the circular motion of open rotor will create sufficient air turbulance to remove the heat without additional implements. To assist this action, both the stator frames and rotor plates are made with vent openings 26, which in the rotor are fitted with extended fan-like blades to blow the air upwards through the gaps between magnet coils, see detail, Fig. 4.

However, in the case of multiple magnets, high density flux generator, this natural cooling will be insufficient and proper centrifugal fan blades shall be fitted between rotor side plates. This rotor fan will drive cooling air from inside out under pressure between magnet coils see Fig. 6.

As a necessary safety measure, the rotor space between stator frames shall be covered by heavy steel bars 27, see Fig. 7 so that they could arrest a magnet in case one may break away from the rotor. A finer mesh 6.

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AI I I 4 4 4l S~ I *t 4 shall be spanned on this safety grid to protect the service personnel from any accidental access into rotor space on top and both sides.

As this generator construction could be used as an electric motor on D.C. and A.C. supply, it would have some advantages over the conventional types as such motor will be free from the "straight jacket" of a heavy external frame and its motive force will be applied on its extremity producing increased turning moment on rotor shaft.

Developing this idea to a practical application on a larger scale, such as electricity supply station for an industrial complex or a population centre with different kinds of electrical power requirements the dual stator generator would be suitable to satisfy any variety.

A typical graphic presentation of such multi-stage generator is shown on an axial side elevation, Fig. 8, Part 1 and 2, which would supply A.C.

in 3, 2 and single phase plus a D.C. for the induction feed to magnet coils of all rotors and to outside supply as well. Such multi-stage unit could be banked-up on a single shaft from one prime mover or two one on each shaft end.

After viewing the preceeding drawings and Specification, this kind of power station is easy to apprehend without further detailed deliberation.

It is sufficient to mention only three points: i) The intermediate 3 stator frames will carry 2 stator windings, one each side and have to be strengthened accordingly; 2) All rotors shall be made of a fly-wheel type with special features in rim construction to accommodate particular shape of electro-magnets in a secured way; and 3) The centrifugal cooling fans have to be fitted to fly-wheel arms, one on each side, to facilitate the forced air circulation from both open ends of the aggregate towards the magnets.

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Claims (2)

1. 6. The Claims defining the Invention are as follows: cu en 1. An electric generator comprising a pair of substantial true vertical and parallel spaced apart stator frames made of non-magnetic material, said stator frames supporting respective opposed annular bands of magnetic material, said wh annular magnetic bands having plurality of radially cut slots accommodating inc stator windings and a disc-shaped rotor disposed between said stator frames, w said rotor bearing on its circumferential periphery multiple radially disposed in *notches having magnet means with minimal air gap between magnet poles and stator windings, said magnet means having North-South polarity at right
2. 8. angles to said stator winding and parallel to rotor axis of rotation. ref 2. An electric generator according to Claim 1 wherein each said stator frame has a centrally disposed hub with a bearing, and wherein said rotor and its shaft supported between two respective stator windings. 4 3. An electric generator according to Claims I and 2 wherein said magnet means comprise permanent or electro-magnet means. 4. An electric generator according to Claims 1 to 3 wherein said shaft I includes a pair of longitudinally extending grooves to locate within said I grooves induction current cables connected to direct current means. An electric generator according to Claims 1 to 4 wherein said rotor shaft includes a drive coupling at one end and a means of induction current at the opposite end for supply of direct current to said electro-magnet means. <1 k i ~I~ 6. An electric generator according to Claims 1 to 5 wherein said induction current supply means include slip rings on said rotor shaft and brush means engaged with said slip rings. 7. An electric generator according to any one of the preceding Claims wherein said rotor includes pair of spaced rotor plates, said rotor plates including a plurality of radially extending slots spaced therearound and wherein said magnet means are supported in respective aligned pairs of slots in the respective said rotor plates. 8. An electric generator substantially as hereinbefore described with reference to the Amended Specification and accompanying drawings. -AfPLCATh Sp( c. t 2o5m 2/88. I PA L. 'T7EfC*o Iv