Glow protection band

• US 6,645,886 B1
• Filed: 07/02/2001
• Issued: 11/11/2003
• Est. Priority Date: 08/28/1998
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Schaefer, Klaus, Muhrer, Volker, Rogler, Wolfgang
• Primary Examiner(s): Dawson, Robert
• Assistant Examiner(s): Keehan, Christopher M
• Application Number:
  US09/786,061
• Time in Patent Office: 862 Days
• Field of Search: 428/413, 428/324, 428/364, 428/368, 428/375, 525/481, 525/485, 525/523, 525/524, 525/533, 525/534, 427/386, 427/389.9, 427/389.1, 427/544, 442/110, 442/139, 442/172
• US Class Current: 442/139
• CPC Class Codes: H01B 3/004 with conductive additives or conductive layers
• CPC Class Codes: H01B 3/008 Other insulating material
• CPC Class Codes: H01B 3/04 mica
• CPC Class Codes: H01B 3/084 Glass or glass wool in binder
• CPC Class Codes: H02K 3/40 for high voltage, e.g. affording protection against corona discharges
• CPC Class Codes: Y10T 428/2933 Coated or with bond, impregnation or core
• CPC Class Codes: Y10T 428/31511 Of epoxy ether
• CPC Class Codes: Y10T 442/2418 Coating or impregnation increases electrical conductivity or anti-static quality
• CPC Class Codes: Y10T 442/2656 Antimony containing
• CPC Class Codes: Y10T 442/2926 Coated or impregnated inorganic fiber fabric

Abstract

A corona shielding band having reproducible qualities and allowing only a small increase in dielectric losses in a winding of an insulation of electrical machine is made by impregnating a woven-type support material with an active resin solution containing an inorganic filler with a coating composed of antimony-doped tin oxide and then removing the solvent by a thermal processing to produce the corona shielding band.

Claims

1. A method of forming a corona shielding band for electrical machines, said method comprising the steps of impregnating a fabric carrier material with a solution of a first constituent containing a reaction resin in a solvent that contains an inorganic filler coated with antimony-doped tin oxide, said solution containing a second constituent selected from accelerators and hardening agents to form an impregnated carrier material, thermally treating the impregnated material to remove the solvent.

2. A method according to claim 1, wherein the contents of the filler material amounts to 0.5 through 75% by weight of the sum of the first and second constituents.

3. A method according to claim 1, wherein the contents of the filler amounts to 2.5 through 25% by weight of the sum of the first and second constituents.

4. A method according to claim 1, wherein part of the antimony in the antimony-doped tin oxide amounts to 0.1 through 30% by weight.

5. A method according to claim 1, wherein the carrier material is a fabric selected from a glass fabric and a fabric of organic material.

6. A method according to claim 1, wherein the carrier material is a fabric of organic material selected from polyester and aromides.

7. A method according to claim 1, wherein the reaction resin is an epoxy resin.

8. A method according to claim 7, wherein the epoxy resin is selected from an aromatic diglycidyl ether and a polyglycidyl ether.

9. A method according to claim 1, wherein the filler is selected from a mica and a titanate.

10. A method according to claim 1, wherein the hardening agent is selected from an aromatic amine and a borotrifluoride amine-adduct.

11. A method according to claim 1, wherein the accelerator is an imidazole derivative.

21. The method of claim 1, wherein the thermal treatment further produces a virtually non-sticky corona shielding band.

22. The method of claim 1, wherein the temperature of the thermal treating is dependent on the solvent.

23. The method of claim 1, wherein the temperature of the thermal treating is dependent on the reactivity of the resin.

12. A method of forming a corona shielding band for electrical machines comprising the steps of providing a fabric carrier material, impregnating the fabric carrier material with a solution of a reaction resin in a solvent containing an inorganic filler coated with antimony-doped tin oxide to form an impregnated carrier material, and removing the solvent from the impregnated carrier material with a thermal treatment.

24. The method of claim 12, wherein the thermal treatment further produces a virtually non-sticky corona shielding band.

25. The method of claim 12, wherein the temperature of the thermal treating is dependent on the solvent.

26. The method of claim 12, wherein the temperature of the thermal treating is dependent on the reactivity of the resin.

13. A corona shielding band for high-voltage electrical machines, said band comprising a fabric carrier material impregnated with a reaction resin containing an inorganic filler coated with antimony-doped tin oxide, wherein the corona shielding band is virtually non-sticky based upon a thermal treatment following impregnation.

14. A corona shielding band according to claim 13, wherein the content of the filler amounts to approximately 2.5 through 75% by weight of the reaction resin.

15. A corona shielding band according to claim 13, wherein the content of the filler is in a range of 2.5 through 25% by weight of the reaction resin.

16. A corona shielding band according to claim 13, wherein the part of antimony in the antimony-doped tin oxide is 0.1 through 30% by weight.

17. A corona shielding band according to claim 13, wherein the carrier material is selected from a glass fabric, a polyester fabric and an aromide fabric.

18. A corona shielding band according to claim 13, wherein the reaction resin is an epoxy resin selected from a group consisting of aromatic diglycidyl ether and aromatic polyglycidyl ether.

19. A corona shielding band according to claim 13, wherein the filler is selected from mica and titanate.

20. A corona shielding band according to claim 13, which includes a hardening agent selected from aromatic amine and borotrifluoride amine-adduct and an accelerator comprising an imidazole derivative.

27. The corona shielding band of claim 13, wherein the temperature of the thermal treatment is dependent on a solvent used in the impregnation of the fabric carrier material.

28. The corona shielding band of claim 13, wherein the temperature of the thermal treatment is dependent on the reactivity of the resin.