DYNAMOELECTRIC MACHINE HAVING ENHANCED COOLING

• US 3,749,950 A
• Filed: 05/23/1972
• Issued: 07/31/1973
• Est. Priority Date: 05/23/1972
• Status: Expired due to Term

• Current Assignee: Henry George Lenz
• Original Assignee: Henry George Lenz
• Inventors: Lenz, Henry George
• Primary Examiner(s): Skudy, R.
• Application Number:
  US05/256,054
• Time in Patent Office: 434 Days
• Field of Search: 310/64,54,58,65,45,259,179,270,215,271 174/120,121 336/206
• US Class Current: 310/45
• CPC Class Codes: H02K 1/20 with channels or ducts for flow of cooling medium
• CPC Class Codes: H02K 15/12 Impregnating, heating or drying of windings, stators, rotors or machines
• CPC Class Codes: H02K 3/38 around winding heads, equalising connectors, or connections thereto
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil

Abstract

A dynamoelectric machine having preformed-coil winding conductors which are wrapped with an open weave tape that affords direct contact between liquid refrigerant circulating through the machine and the end turn portions of the conductors forming the coils. The slot portions of the winding coils preferably are wrapped with a solid dielectric tape to maximize thermal contact between the coil sides and adjacent magnetic laminations of the machiner stator.

Claims

1. A dynamoelectric machine having thermal transfer characteristics comprising:

a. a magnetizable member having a substantially cylindrical surface, b. a plurality of axially extending slots circumferentially spaced in said member and opening into said cylindrical surface, c. a conductive winding in said member formed of a plurality of preformed coils, the sides of said coils being situated in said slots and the end turn regions of said coils extending axially from opposite ends of said magnetizable member, d. at least the end turn regions of said coils being wrapped with open weave tape to permit substantially unobstructed flow of coolant between strands of said tape to contact the underlying electrical conductors forming said coils.

2. A dynamoelectric machine according to claim 1 wherein said open weave tape is formed by a lock weave to secure at least one thread in relatively fixed location along the tape.

3. A dynamoelectric machine according to claim 2 further including an electrically insulating adhesive coated atop said taped end turn regions, said adhesive having a thickness upon curing less than the thickness of the fibers forming said tape and having an initial viscosity and surface tension upon application to said coils to penetrate through said open weave tape into contact with the underlying conductors.

4. A dynamoelectric machine according to claim 3 wherein said tape has a width in excess of 0.3 inches and the longitudinal strands of said tape are separated by a span greater than 0.05 inches.

5. A dynamoelectric machine according to claim 4 wherein said open weave tape is wound upon said end turn regions in a butt lap.

6. A dynamoelectric machine having thermal transfer characteristics comprising:

a. a magnetizable member having a substantially cylindrical surface, b. a plurality of axially extending slots circumferentially spaced in said member and opening into said cylindrical surface, c. a conductive winding in said member formed of a plurality of preformed coils, each said preformed coil including a plurality of insulated conductors shaped into a geometric configuration permitting said coil to be positioned within predetermined circumferentially spaced slots and an insulating covering atop said conductors to maintain said conductors in relatively fixed position relative to each other, d. means for circulating a fluid coolant through said machine to cool said machine, and e. the portion of said insulating covering upon the sides of said coils situated within said slots having a weave substantially impervious to said circulating coolant and the portion of said insulating covering upon the end turn regions situated outside said magnetizable member having an open weave to permit substantially unobstructed contact between said coolant and said conductors underlying said insulating covering.

7. A dynamoelectric machine according to claim 6 wherein said fluid refrigerant is a liquid and said covering upon said end turn regions is a lock weave tape of non-hydroscopic material.

8. A dynamoelectric machine according to claim 7 further including an electrically insulating adhesive oVerlying said stranded tape and contacting said underlying conductors, the thickness of said adhesive upon curing being substantially less than the thickness of the strands forming said tape.

9. A dynamoelectric machine having thermal transfer characteristics comprising:

a. a magnetizable member having a substantially cylindrical surface, b. a plurality of axially extending slots circumferentially spaced in said member and opening into said cylindrical surface, c. a conductive winding in said member formed of a plurality of preformed coils, the sides of said coils being situated in said slots and the end turn regions of said coils extending axially from said magnetizable member, d. means for circulating a liquid refrigerant through said machine to cool said machine windings, said circulating means including means for passing said liquid refrigerant into direct contact with said end turn regions of said conductive windings, e. an open weave electrical insulating covering said end turn regions and mechanically securing the conductors forming an individual coil into separate, spaced apart groups, said open weave insulation having a weave locking at least one thread in relatively fixed location along the tape to provide a plurality of openings therein in excess of 0.03 sq. inch permitting substantially unobstructed contact between said refrigerant and said end turns, f. an electrical insulation covering the sides of said end turns disposed within the slots of said machine, said electrical insulation being a solid dielectric substantially impervious to the liquid refrigerant flowing through said machine, and g. means for directing said refrigerant through axial passages in said magnetizable member to cool the sides of said coils by conduction of heat from said coil sides through the magnetic member to said flowing refrigerant.

10. A dynamoelectric machine according to claim 9 wherein said open weave electrical insulation is a polyester tape having a width greater than 0.3 inches.

11. A dynamoelectric machine according to claim 10 wherein said polyester tape is butt lapped around said end turn regions and further including an electrically insulating adhesive coated thereon, said adhesive having a viscosity upon application to said tape sufficient to permit penetration of said adhesive through the tape into direct contact with the underlying conductors, the thickness of said adhesive upon curing being less than the thickness of said tape to maximize thermal contact between said refrigerant and said conductors forming said preformed coil.