Rotor winding shield for a superconducting electric generator
View Patent ↗A generator rotor core ( 54 ) carrying superconducting windings ( 60 ) and having a shield ( 426 ) over the superconducting windings ( 60 ) to prevent external magnetic fields from impinging the windings. Axial shield edges ( 430/434 ) mate with corresponding features of the rotor core ( 54 ) or with structures affixed to or supported by the core ( 54 ) to support the shield ( 426 ).
1. A rotor for an electric generator, the rotor comprising:
a rotor core defining a first and a second axially extending flat surface region, each of the first and the second flat surface regions bounded by first and second opposing edges;
a superconducting winding circumscribing the rotor core, axial segments of the superconducting winding disposed within the first and the second flat surface regions;
a plurality of first and a plurality of second core extension elements mating with the respective first edge of the first and the second flat surface regions;
a first arcuate shield extending axially along the rotor core enclosing the axial segment within the first flat surface region, the first shield having a first axial edge mating with a first edge of the plurality of first core extension elements and a second axial edge mating with the second edge of the first flat surface region; and
a second arcuate shield extending axially along the rotor core enclosing the axial segment within the second flat surface region, the second shield having a first axial edge mating with a first edge of the plurality of second extension elements and a second axial edge mating with the second edge of the second flat surface region.
2. The rotor of claim 1 further comprising:
a first and a second rotor end section affixed to respective first and second ends of the rotor core;
a first and a second shield end segment mating with the respective first and second rotor end section for closing an opening formed by the first shield disposed over the first flat surface region; and
a third and a fourth shield end segment mating with the respective first and second rotor end section for closing an opening formed by the second shield disposed over the second flat surface region.
3. The rotor of claim 1 wherein a material of the plurality of first core extension elements and the plurality of second core extension elements comprises a ferromagnetic material.
4. The rotor of claim 1 wherein a material of the first and the second shields comprises an electrically conductive non-magnetic material.
5. The rotor of claim 1 wherein a material of the first and the second shields comprises copper.
6. The rotor of claim 1 further comprising:
a first shoe interposed between and supporting the first edge of the first shield and the first edge of the plurality of first core extension elements; and
a second shoe interposed between and supporting the second edge of the first shield and the second edge of the first flat surface region.
7. The rotor of claim 6 wherein the first shoe comprises a first dovetail feature mating with a groove defined in the first edge of the first shield and a second dovetail feature mating with a groove defined in the first edge of the plurality of first core extension elements, and wherein the second shoe comprises a third dovetail feature mating with a groove defined in the second edge of the first shield and a fourth dovetail feature mating with a groove defined in the second edge of the first flat surface region.
8. The rotor of claim 1 further comprising:
a first shoe interposed between and supporting the first edge of the second shield and the first edge of the plurality of second core extension elements and a second shoe interposed between and supporting the second edge of the second shield and the second edge of the second flat surface region.
9. The rotor of claim 8 wherein the first shoe comprises a first dovetail feature mating with a groove defined in the first edge of the second shield and a second dovetail feature mating with a groove defined in the first edge of the plurality of second core extension elements, and wherein the second shoe comprises a third dovetail feature mating with a groove defined in the second edge of the second shield and a fourth dovetail feature mating with a groove defined in the second edge of the second flat surface region.
10. The rotor of claim 1 wherein each of the plurality of first and the plurality of second core extension elements comprises the first edge and a second axial edge, the second axial edge comprising a dovetail feature for mating with a corresponding groove in the first edge of the respective first and second flat surface regions.
11. The rotor of claim 1 wherein each of the plurality of first and the plurality of second core extension elements comprises a plurality of core extension blocks configured in an end-to-end relation.