Electrical bushing with resin casting

Abstract

The invention in a first aspect relates to an improved cast resin bushing assembly for use in a transformer wherein the busing assembly includes a bushing which includes locating means for aligning the bushing assembly within a transformer casing; wherein the bushing further includes a locking means for releasably securing the bushing assembly to a transformer casing; a bushing conductor; and a bushing flange in circumferential arrangement with the bushing. In a second aspect the invention relates to a method of securing an improved cast resin bushing assembly to a transformer casing which bushing assembly includes a bushing which includes a locating means for aligning the bushing assembly within a transformer casing; the bushing further includes a locking means for releasably securing the bushing assembly to a transformer casing; a bushing conductor, and a bushing flange in circumferential arrangement to the bushing; wherein the transformer casing has an opening adapted to receive the bushing assembly or part thereof; and the bushing flange is mounted on the outside of the transformer casing and secured thereto by engaging the locking means on the inside of the transformer casing.

1. An improved cast resin busing assembly for use in a transformer including:
 a bushing which includes locating means for aligning the bushing assembly within a transformer casing;  
 said busing further comprising locking means for releasably securing the bushing assembly to said transformer casing;  
 said locking means including a threaded section moulded into the bushing that is adapted to be engaged by a collar inside said transformer casing;  
 a bushing conductor integrally moulded to said bushing; and  
 a bushing flange in circumferential arrangement with the bushing.  
 
     
     
       2. An improved cast resin bushing assembly according to  claim 1  wherein the bushing assembly is cast in a one step moulding. 
     
     
       3. An improved cast resin bushing assembly according to  claim 1  wherein the threaded section of the bushing and the collar are cast from a singular resin moulding so as to form complementary engageable components. 
     
     
       4. An improved cast resin bushing assembly according to  claim 1  wherein the locating means is a groove or flat position on the bushing for aligning the bushing assembly within an opening in said transformer casing. 
     
     
       5. An improved cast resin bushing assembly according to  claim 1  wherein the bushing flange is adapted to be mounted on said transformer casing. 
     
     
       6. An improved cast resin bushing assembly according to  claim 1  wherein the bushing flange includes locking holes which can be used as additional alternate means of securing the bushing assembly to the transformer casing. 
     
     
       7. An improved cast resin bushing assembly according to  claim 1  wherein the bushing flange and the bushing constitute a single moulded piece. 
     
     
       8. An improved cast resin bushing assembly according to  claim 1  wherein the flange is substantially annular and has an outside diameter larger than the transformer opening. 
     
     
       9. An improved cast resin bushing assembly according to  claim 1  wherein the bushing conductor is cast integrally within the bushing. 
     
     
       10. An improved cast resin bushing assembly according to  claim 1  wherein the cast resin system is selected from epoxy, phenolics, polyester, vinylester, polyurethane and related composites. 
     
     
       11. An improved cast resin bushing assembly according to  claim 1  wherein the collar can be a cast resin nut or cyclo nut. 
     
     
       12. A method of releasably securing an improved cast resin bushing assembly to a transformer casing having an opening by providing:
 a bushing which includes locating means for aligning the bushing assembly or part thereof within said opening in said transformer casing;  
 the bushing further includes locking means for releasably securing the bushing assembly to said transformer casing; the locking means including a threaded section moulded into the bushing which is adapted to be engaged by a collar inside said transformer casing;  
 a bushing conductor integrally moulded to said bushing; and  
 a bushing flange in circumferential arrangement to the bushing;  
 
       said method including the steps of:
 positioning said locating means on said bushing within said opening in said transformer casing so as to align said bushing assembly;  
 mounting said bushing flange on an outside surface surrounding the opening in said transformer casing; and,  
 releasably securing the bushing assembly within the transformer casing by engaging said locking means inside the transformer casing.  
 
     
     
       13. A method of releasably securing an improved cast resin bushing assembly to a transformer casing according to  claim 12  wherein the bushing assembly is cast in a one step moulding. 
     
     
       14. A method according to  claim 12  wherein the threaded section of the bushing and the collar are cast from a singular resin moulding so as to form complementary engageable components. 
     
     
       15. A method according to  claim 12  wherein the collar can be a cast resin nut or cyclo nut. 
     
     
       16. A method according to  claim 12  wherein the locating means is a groove or flat position on the bushing for aligning the bushing assembly within an opening in said transformer casing. 
     
     
       17. A method according to  claim 12  wherein the bushing flange is adapted to be mounted on said transformer casing. 
     
     
       18. A method according to  claim 12  wherein the bushing flange includes locking holes which can be used as additional or alternate means of securing the bushing assembly to the transformer casing. 
     
     
       19. A method according to  claim 12  wherein the bushing flange and the bushing constitute a single moulded piece. 
     
     
       20. A method according to  claim 12  wherein the flange is substantially annular and has an outside diameter larger than the transformer opening. 
     
     
       21. A method according to  claim 12  the bushing conductor is cast integrally within the bushing. 
     
     
       22. A method according to  claim 12  wherein the cast resin system is selected from epoxy, phenolics, polyester, vinylester, polyurethane and related composites. 
     
     
       23. A method of releasably securing an improved cast resin bushing assembly to a transformer casing having an opening by providing a bushing assembly including:
 a bushing which is formed from a cast resin polymer and which includes locating means defined by one of a groove or flat portion for aligning the bushing assembly or part thereof within said opening in the transformer casing;  
 the bushing further includes a threaded section for securing the bushing assembly to the transformer casing;  
 a threaded collar;  
 a bushing conductor integrally moulded to said bushing; and  
 a bushing flange in circumferential arrangement with the bushing;  
 
       said method includes the steps of:
 positioning said locating means on said bushing within said opening in said transformer casing so as to align said bushing assembly;  
 mounting said bushing flange on an outside surface surrounding said opening in said transformer casing; and,  
 releasably securing the bushing assembly within the transformer casing by engaging the threaded section on the bushing on the inside of the transformer casing with the threaded collar.  
 
     
     
       24. An improved cast resin bushing assembly for use in a transformer including:
 a bushing which is made from a cast resin polymer, which is cast in angular or bifurcated construction relative to a transformer casing and which includes located means for aligning the bushing assembly within the transformer casing;  
 said busing further comprising locking means for releasably securing the bushing assembly to said transformer casing;  
 a bushing conductor integrally moulded to said bushing; and  
 a bushing flange in circumferential arrangement with the bushing.  
 
     
     
       25. An improved cast resin bushing assembly for use in a transformer including:
 a bushing which includes locating means for aligning the bushing assembly within a transformer casing;  
 said bushing being cast from a cycloaliphatic epoxy resin system;  
 said busing further comprising locking means for releasably securing the bushing assembly to said transformer casing;  
 a bushing conductor integrally moulded to said bushing;  
 a bushing flange in circumferential arrangement with the bushing.  
 
     
     
       26. A method of releasably securing an improved cast resin bushing assembly to a transformer casing having an opening by providing:
 a bushing which includes a locating means for aligning the bushing assembly or part thereof within said opening in said transformer casing; the bushing further includes a locking means for releasably securing the bushing assembly to said transformer casing;  
 a bushing conductor integrally moulded to said bushing; and  
 a bushing flange in circumferential arrangement to the bushing; positioning said locating means on said bushing within said opening in said transformer casing so as to align said bushing assembly;  
 
       and said method comprising the steps of:
 casting said bushing from a cycloaliphatic epoxy resin system;  
 mounting said bushing flange on an outside surface surrounding the opening in said transformer casing; and,  
 releasably securing the bushing assembly within the transformer casing by engaging said locking means inside the transformer casing.