Electrical bushing

An electrical insulating bushing comprising:

• a hollow electrical conductor having inner and outer surfaces and first and second ends;
• a first longitudinally extending member surrounding and radially spaced from said conductor and defining a first longitudinally extending annular channel between said outer surface of said conductor and said first member;
• a second longitudinally extending member concentrically disposed within and radially spaced from said conductor and defining a second longitudinally extending annular channel between said inner surface of said conductor and said second member;
• an electrical insulating housing surrounding and spaced from said first member and defining a longitudinally extending third channel therebetween;
• dielectric fluid filling said housing to a predetermined level;
• means for introducing said fluid into said first and second channels in parallel such that said fluid will flow in parallel through said first and second channels and thereby dissipate heat from said inner and outer surfaces of said conductor, respectively;
• said first and second channels being disposed in fluid flow communication with said third channel such that the heat contained in said fluid is transferred to the ambient air through said housing as said fluid flows through said third channel;
• said conductor containing an aperture adjacent its first end and a casing surrounding the portions of said conductor containing said aperture;
• said casing having first and second ends through which said conductor extends, said first end of said casing sealably connected to said conductor, said second end of said casing sealably connected to said electrical insulative housing;
• spring means disposed within said casing, for exerting tensile stress on said conductor and compressive stress on said second end of said casing to hold said casing in sealed relationship with said insulative housing;
• and
• means for disposing said casing in fluid flow communication with said housing such that a fluid flow path is formed between the second and third channels through said aperture and said casing in which said dielectric fluid is diverted across the surface of said casing as it flows therethrough.

An electrical insulating bushing comprising:

• a hollow electrical conductor having first and second sealed ends;
• a layer of electrical insulating material surrounding and radially spaced from a portion of said conductor and defining a longitudinally extending first annular channel between said conductor and said layer of insulative material;
• a longitudinally extending tubular member concentrically disposed within and radially spaced from said conductor and defining a longitudinally extending second annular channel between said conductor and said tubular member, said tubular member extending the entire length of said conductor;
• an electrical insulative housing having first and second ends, said housing surrounding and spaced from said layer of insulative material and defining a longitudinally extending third channel between said insulative housing and said layer of insulative material, said third channel disposed in fluid flow communication with said first channel, said first end of said insulative housing sealably connected to said conductor;
• said conductor having a plurality of first apertures adjacent said second end defining a fluid flow path between said second channel and said third channel;
• said first channel having a fluid flow resistance that is substantially equal to the fluid flow resistance of said second channel;
• a hollow casing having first and second ends with said conductor extending therethrough, said first end of said casing being sealably connected to said conductor, said second end of said casing being sealably connected to said second end of said insulative housing and spaced from said conductor;
• said conductor having a plurality of external threads at a predetermined position on the portion of said conductor disposed within said casing;
• a compression spring assembly disposed within said casing;
• said spring assembly including first and second spaced annular spring seats, said first spring seat disposed adjacent said threaded portion of said conductor, said second spring seat disposed adjacent said second end of said casing and bearing thereon, a plurality of compression springs being circumferentially disposed between said first and second spring seats and bearing thereon, a spring support collar threadably engaged with said threads on said conductor and disposed on the opposite side of said first spring seat from said compression springs to resist outward force exerted thereon;
• a first annular insulative member disposed between said first spring seat and said conductor;
• a second annular insulative member disposed between said second spring seat and said conductor;
• said conductor including a plurality of circumferentially spaced second apertures in the portion of said conductor disposed within said casing, said second apertures disposing said second channel in fluid flow communication with said casing;
• said second spring seat including a plurality of radially extending ducts, one end of said ducts disposed in fluid flow communication with said casing, the other end of said ducts disposed in fluid flow communication with said third channel in said insulative housing such that a fluid flow path is defined between said second apertures in the portion of said conductor contained within said casing, said casing, said ducts, and said third channel in said electrical insulative housing;
• and
• dielectric fluid filling said housing and said casing to a predetermined level above said second apertures in said conductor.

Electrical inductive apparatus comprising:

• a sealed enclosure;
• an electrical member disposed in said enclosure;
• dielectric fluid disposed in said enclosure;
• an electrical insulating bushing extending through said enclosure, said electrical insulating bushing comprising:
• a hollow electrical conductor having inner and outer surfaces and first and second ends;
• a first longitudinally extending member surrounding and radially spaced from said conductor and defining a first longitudinally extending annular channel between said outer surface of said conductor and said first member, said first longitudinally extending member being formed of electrical insulating material;
• a second longitudinally extending member concentrically disposed within and radially spaced from said conductor and defining a second longitudinally extending annular channel between said inner surface of said conductor and said second member;
• an electrical insulating housing surrounding and spaced from said first member and defining a longitudinally extending third channel therebetween;
• and
• dielectric fluid filling said housing to a predetermined level;
• said first and second channels being disposed in fluid flow communication with said third channel at opposite ends of said electrical conductor such that said dielectric fluid will flow in parallel through said first and second channels and thereby remove heat from said inner and outer surfaces of said conductor, respectively, which heat is dissipated to the ambient air through said housing as said dielectric fluid flows through said third channel, said first and second channels having substantially equal fluid flow resistances such that said dielectric fluid flows through both of said first and second channels at substantially the same flow rate, said first, second and third channels further being disposed in fluid flow communication with said enclosure.