US3679920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Superconducting dynamo-electric machines
Assignee: JOHN THOMPSON (PIPEWORK AND ORDNANCE DIVISION) Ltd
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Filing: 1971-04-01
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Granted: 1972-07-25
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Expires: 1991-04-01
Abstract
Abstract An A.C. generator has a superconducting D.C. field winding on the rotor and a multi-phase A.C. winding on the stator. To prevent A.C. loss in the superconducting winding an electromagnetic flux screen is interposed between the windings and is secured to the rotor. In a preferred construction the flux screen is part of an outer rotor cylinder of strong mechanical construction which operates at ambient temperature. The outer rotor cylinder is coupled for rotation with an inner cylinder which carries the superconducting winding, is of relatively light construction to minimize heat inflow and is separated from the outer cylinder by a vacuum space.
Inventors
- 👤 Robert Beattie Macnab
- 👤 Brian Edward Mulhall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:33
CPC Classifications
H; H02; H02K; H02K55/00; H02K55/02; H02K55/04; H02K19/00; H02K19/16; H02K19/26; Y; Y02; Y02E; Y02E40/00; Y02E40/60
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
121 words
A dynamo-electric machine having a stator winding and a rotor winding, said rotor winding being a superconducting direct current winding, and said stator winding being designed to carry alternating currents which in the operation of the machine will tend to produce a magnetic flux pattern varying with respect to said superconducting winding, wherein the rotor structure of the machine includes an electromagnetic flux screen disposed between the two windings and which rotates with said superconducting winding but is fixed relative to said superconducting winding, said flux screen shielding said superconducting winding from the said varying flux pattern and thereby preventing A.C. loss in said superconducting winding while allowing the constant flux of said superconducting winding to interact with said stator winding.
Claim 2
Dependent Claim
121 words
A dynamo-electric machine having a stator winding and a rotor winding, said rotor winding being a superconducting direct current winding, and said stator winding being designed to carry alternating currents which in the operation of the machine will tend to produce a magnetic flux pattern varying with respect to said superconducting winding, wherein the rotor structure of the machine includes an electromagnetic flux screen disposed between the two windings and which rotates with said superconducting winding but is fixed relative to said superconducting winding, said flux screen shielding said superconducting winding from the said varying flux pattern and thereby preventing A.C. loss in said superconducting winding while allowing the constant flux of said superconducting winding to interact with said stator winding.
Claim 3
Dependent Claim
31 words
A dynamo-electric machine as claimed in claim 1 in which the screen is spaced from the superconducting winding and the space is evacuated to provide heat insulation for the superconducting winding.
Claim 4
Dependent Claim
27 words
A dynamo-electric machine as claimed in claim 2 having a radiation shield disposed in the evacuated space and spaced from the screen and from the superconductiNg winding.
Claim 5
Dependent Claim
38 words
A dynamo-electric machine as claimed in claim 1 in which the rotor comprises an inner part carrying the superconducting winding and an outer part carrying the screen, the two parts being supported coaxially and locked against relative rotation.
Claim 6
Dependent Claim
66 words
A dynamo-electric machine as claimed in claim 4 in which the outer rotor part has at each end a sleeve shaft supported in a bearing and the inner part has a central section carrying the superconducting winding and end sections of hollow frusto-conical form joining the central section to stub shafts mounted within and coupled for rotation with the sleeve shafts of the outer rotor part.
Claim 7
Dependent Claim
60 words
A dynamo-electric machine as claimed in claim 5 in which the outer part is spaced from the inner part throughout the length of the central and end sections of the inner part, the sleeve shafts of the outer part are sealed to the stub shafts of the inner part and the space between the inner and outer parts is evacuated.
Claim 8
Dependent Claim
19 words
A dynamo-electric machine as claimed in claim 6 having a thermal radiation shield disposed in the said vacuum space.
Claim 9
Dependent Claim
36 words
A dynamo-electric machine as claimed in claim 4 in which the screen comprises a cylindrical wall of metal of high electrical conductivity and a cylindrical supporting wall of higher mechanical strength closely surrounds the screen wall.
Claim 10
Dependent Claim
23 words
A dynamo-electric machine as claimed in claim 8 in which the supporting wall and the screen wall are held together by shrink fitting.
Claim 11
Dependent Claim
21 words
A dynamo-electric machine as claimed in claim 9 in which the supporting wall is composed of a plurality of elemental rings.
Claim 12
Dependent Claim
30 words
A dynamo-electric machine as claimed in claim 1 in which the rotor comprises a supporting body with the superconducting winding located in the radially outer surface of the supporting body.
Claim 13
Dependent Claim
16 words
A dynamo-electric machine as claimed in claim 11 having winding retaining sleeves encircling the supporting body.
Claim 14
Dependent Claim
24 words
A dynamo-electric machine as claimed in claim 1 in which the rotor comprises a hollow supporting body within which the superconducting winding is mounted.
Claim 15
Dependent Claim
16 words
A dynamo-electric machine as claimed in claim 1 in which the flux screen includes superconducting material.
Claim 16
Dependent Claim
37 words
A dynamo-electric machine as claimed in claim 14 in which the rotor comprises a supporting body on which the superconducting winding is mounted and the screen is mounted on the radially outer surface of the supporting body.
Claim 17
Dependent Claim
33 words
A dynamo-electric machine as claimed in claim 15 in which the screen is in thermal communication with the superconducting rotor winding whereby the screen is cooled by the cooling system for the winding.
Claim 18
Dependent Claim
23 words
A dynamo-electric machine as claimed in claim 16 in which the superconducting winding is mounted on the inside of a hollow supporting body.
Claim 19
Dependent Claim
23 words
A dynamo-electric machine as claimed in claim 16 in which the superconducting winding is located in the outer surface of the supporting body.
Claim 20
Dependent Claim
18 words
A dynamo-electric machine as claimed in claim 18 having retaining sleeves surrounding the screen and the superconducting winding.
Claim 21
Dependent Claim
27 words
A machine as claimed in claim 15 in which the screen consists of lengths of superconducting material supported in a matrix of highly thermally conductive, non-superconducting material.
Claim 22
Dependent Claim
31 words
A machine as claimed in claim 15 having a casing spaced from and surrounding the superconducting screen and winding on the supporting body to form a vacuum space for thermal insulation.
References Cited (Backward Citations)
US3005117A
Cited
US3368087A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |