Support method and structure for epoxy impregnated saddle-shaped superconducting windings

• US 4,385,248 A
• Filed: 12/17/1980
• Issued: 05/24/1983
• Est. Priority Date: 12/17/1980
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Laskaris, Evangelos T.
• Primary Examiner(s): Skudy, R.
• Application Number:
  US06/217,329
• Time in Patent Office: 888 Days
• Field of Search: 310/43, 310/56, 310/51, 310/52, 310/271, 310/214, 310/215, 310/91, 310/179, 310/208, 310/254, 310/258, 310/261, 310/264, 310/265, 310/85, 310/180, 310/184, 310/198, 310/10, 310/64, 336/197, 336/DIG. 1, 29/596, 29/598, 29/599, 174/15 S, 335/216
• US Class Current: 310/52
• CPC Class Codes: H02K 3/46 Fastening of windings on the stator or rotor structure
• CPC Class Codes: H02K 55/00 Dynamo-electric machines having windings operating at cryogenic temperatures
• CPC Class Codes: Y02E 40/60 Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
• CPC Class Codes: Y10T 29/49009 Dynamoelectric machine
• CPC Class Codes: Y10T 29/49012 Rotor

Abstract

A method and structure for restricting relative sliding motion at the interfaces between a superconducting winding and a supporting structure for the winding. An interface lining material having a low shear modulus of elasticity so as to accommodate large shear displacements with low shear stresses is used as opposed to the use of sliding frictional contact between the contacting surfaces of the electrical winding and the supporting structure. The invention is completed by subjecting the lined interfaced surfaces to large compressional pressure forces so that frictional forces between the interface material and the opposing superconducting winding and supporting structure surfaces, even at low coefficients of friction, are considerably higher than the internal shear forces of the interfacing lining material. The superconducting winding is comprised of a plurality of conductors of superconducting material bunched together in close thermal contact with each other and secured in a solid winding bundle by epoxy resin. The interface lining material preferably is wrapped completely around and surrounds the superconducting winding.

Claims

1. The method of restricting relative sliding motion at the interfaces between a superconducting winding and a supporting structure for said winding by means of the internal shear strain developed within an interface material having a low shear modulus of elasticity so as to accommodate large shear displacements with low shear stresses;

said method comprising lining the interfaces between said superconducting winding and said supporting structure with interface material such as leather having a low shear modulus of elasticity below about 60,000 psi and subjecting the lined interface surfaces to large compressional pressure forces so that frictional forces between the interface material and the interfacing superconducting winding and supporting structure surfaces, even at low coefficients of friction, are considerably higher than the internal shear forces of the interface.

2. The method according to claim 1 wherein the interface material having low shear modulus of elasticity comprises a material selected from the group of materials consisting of leather, cellulose paper, and polyethylene paper.

3. The method according to claim 1 wherein the superconducting winding is comprised of a plurality of conductors of superconducting material bunched together in close thermal contact with one another.

4. The method according to claim 3 further comprising supplying cryogenic cooling fluid to channels within said supporting structure for bringing said cooling fluid into direct contact with said interface material.

5. The method according to claim 4 wherein the interface material is wrapped around and completely surrounds the superconducting winding and comprises a material selected from the group consisting of leather, cellulose paper, and polyethylene paper.

6. The method according to claim 1 wherein the superconducting winding is comprised of a plurality of saddle-shaped windings physically nested together one within the other and the supporting structure is comprised of two semi-cylindrical inner and outer shells compressed together with the nested saddle-shaped windings disposed within an annular space defined between the inner and outer shells and further including complementary-shaped core members and wedge-shaped wedging members tightly wedged intermediate the nested saddle-shaped windings within the annular space defined between the inner and outer shells for subjecting all of said members including the nested saddle-shaped windings and the interior surfaces of the inner and outer shells to large compressional pressure forces.

7. The method according to claim 7 wherein the superconducting winding is comprised of a plurality of conductors of superconducting material bunched together in close thermal contact with one another.

8. The method according to claim 7 further comprising supplying cryogenic cooling fluid to channels within said supporting structure for bringing said cooling fluid into direct contact with said interface material.

9. The method according to claim 7 wherein the interface material is wrapped around and completely surrounds the superconducting winding and comprises a material selected from the group consisting of leather, cellulose paper and polyethylene paper.

10. A new and improved superconducting winding and a support structure therefor together with means for restricting relative sliding motion at the interfaces between said superconducting winding and said support structure to thereby limit friction-generated heat by said winding during operation, said means comprising an interface lining material of leather having a low shear modulus of elasticity disposed between the interfacing surfaces of said superconducting winding and said support structure, and means for subjecting said lined interface surfaces to large compressional pressure forces so that frictional forces between the interface lining material and the interfacing superconducting winding and support structure surfaces, even at low coefficients of friction, are considerably higher than the internal shear forces of the interface lining material.

11. The superconducting winding and support structure according to claim 10 wherein the superconducting winding comprises a plurality of conductors of superconducting material bunched together in close thermal contact with each other and secured in a solid winding bundle by epoxy resin.

12. The superconducting winding and support structure according to claim 11 further comprising cooling channel means disposed within surfaces of said support structure for bringing cryogenic cooling fluid into direct contact with said interface material.

13. The superconducting winding and support structure according to claim 10 wherein the superconducting winding is comprised of a plurality of saddle-shaped windings physically nested one within the other and the support structure is comprised of two semi-cylindrical shells compressed together with the nested saddle-shaped windings disposed within an annular space defined between the inner and outer shells and further including complementary-shaped core members and wedging members tightly wedged intermediate the nested saddle-shaped winding within the space defined between the inner and outer shells for subjecting all of said members including the nested saddle-shaped windings and the interior surfaces of the inner and outer shells to large compressional pressure forces.

14. The electrical winding and support structure according to claim 13 wherein the superconducting winding is comprised of a plurality of conductors of superconducting material bunched together in close thermal contact with each other and secured in a solid winding bundle by epoxy resin.

15. The superconducting winding and support structure according to claim 14 further comprising cooling channel means disposed within surfaces of said support structure for bringing cryogenic cooling fluid into direct contact with said interface material.