Gas-cooled electric machine

• US 5,276,374 A
• Filed: 05/26/1992
• Issued: 01/04/1994
• Est. Priority Date: 06/15/1991
• Status: Expired due to Fees

• Current Assignee: Alstom SA
• Original Assignee: Asea Brown Boveri Ltd (ABB Limited)
• Inventors: Lanz, Stefan, Novosel, Ivan, Geller, Marius, Zimmermann, Hans
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): LABALLE, CLAYTON E
• Application Number:
  US07/887,935
• Time in Patent Office: 588 Days
• Field of Search: 310/52, 310/55, 310/56, 310/58, 310/59, 310/60 R, 310/60 A, 310/260
• US Class Current: 310/59
• CPC Class Codes: H02K 3/24 with channels or ducts for cooling medium between the conductors
• CPC Class Codes: H02K 3/505 for large machine windings, e.g. bar windings H02K3/51 takes precedence
• CPC Class Codes: H02K 9/00 Arrangements for cooling or ventilating channels or ducts in parts of the magnetic circuit H02K1/20, H02K1/32; channels or ducts in or between conductors H02K3/22, H02K3/24

Abstract

In the gas-cooled electric machine, the stator winding bars, which are connected to one another electrically and mechanically outside the stator core assembly (2) in the overhang space by means of metallic lugs, are provided with caps (8) which virtually completely surround the lugs while leaving free one or more approximately axially extending ducts (9). These ducts (9) are open towards the stator core assembly (2). At its end on the partition side, the cap (8) has an opening (10) which is freely connected to said ducts (9). A flexible line (11) leads from this opening directly into the suction chamber (14) of the fan (5).

As a consequence of the pressure difference between the suction chamber (14) and overhang space (13), some of the coolant conveyed by the fan (5) flows through said ducts and cools the rod ends and lugs (7).

Claims

1. A gas-cooled electric machine having a rotor, a stator having an indirectly cooled stator winding and a housing surrounding the stator, having one or two stator winding bars, which are located one above the other in a groove, are built up from mutually insulated component conductors and are connected to one another electrically and mechanically outside the stator core assembly in the overhang space by means of metallic lugs to form a winding, and a fan on each machine side whose suction chamber is separated by a partition from the overhang space, wherein the lugs are provided with a cap which surrounds the lugs, and there are provided in the lugs or in the cap ducts which extend essentially axially and are open towards the stator core assembly and in communication with said overhang space such that cooling gas flows from said overhang space into said ducts, and the cap has at its end on the partition side an opening which is freely connected to said ducts and is connected to a flexible line which leads directly into the suction chamber of the fan.

2. The electric machine as claimed in claim 1, wherein the lugs are provided with through-bores which extend essentially axially.

3. A gas-cooled electric machine having a rotor, a stator and a housing surrounding the stator, having one or two stator winding bars, which are located one above the other in a groove, are built up from mutually insulated component conductors and are connected to one another electrically and mechanically outside the stator core assembly in the overhang space by means of metallic lugs to form a winding, and a fan on each machine side whose suction chamber is separated by a partition from the overhang space, wherein the lugs are provided with a cap which surrounds the lugs, and there are provided in the lugs or in the cap ducts which extend essentially axially and are open towards the stator core assembly, and the cap has at its end on the partition side an opening which is freely connected to said ducts and is connected to a flexible line which leads directly into the suction chamber of the fan;

wherein the lugs are provided with cooling ribs which extend essentially axially.

4. A gas-cooled electric machine having a rotor, a stator and a housing surrounding the stator, having one or two stator windings bars, which are located one above the other in a groove, are built up from mutually insulated component conductors and are connected to one another electrically and mechanically outside the stator core assembly in the overhang space by means of metallic lugs to form a winding, and a fan on each machine side whose suction chamber is separated by a partition from the overhang space, wherein the lugs are provided with a cap which surrounds the lugs, and there are provided in the lugs or in the cap ducts which extend essentially axially and are open towards the stator core assembly, and the cap has at its end on the partition side an opening which is freely connected to said ducts and is connected to a flexible line which leads directly into the suction chamber of the fan;

wherein the interior of the cap is provided with inwardly directed projections which leave ducts free between them.

5. A gas-cooled electric machine having a rotor, a stator having an indirectly cooled stator winding and a housing surrounding the stator, having one or two stator winding bars, which are located one above the other in a groove, are built up from mutually insulated component conductors and are connected to one another electrically and mechanically outside the stator core assembly in the overhang space by means of metallic lugs to form a winding, and a fan on each machine side whose suction chamber is separated by a partition from the overhang space, wherein the lugs are provided with a cap which surrounds the lugs, and there are provided in the lugs or in the cap ducts which extend essentially axially and are open towards the stator core assembly and in communication with said overhang space such that cooling gas flows from said overhang space into said ducts, and the cap has at its end on the partition side an opening which is freely connected to said ducts and is connected to a flexible line which leads directly into the suction chamber of the fan, wherein said ducts extend along an outside portion of said winding bars such that cooling gas from said overhang space flows along said ducts to thereby cool end portions of the stator winding.

6. A gas-cooled electric machine having a rotor, a stator having an indirectly cooled stator winding and a housing surrounding the stator, having at least one winding bar which extends outside of a stator core assembly into an overhang space, and wherein an end portion of said at least one winding bar is received within a cap, and further wherein cooling ducts are provided within an interior of said cap and and outside of said winding bar, wherein said ducts are open towards and in communication with said overhang space, and wherein a fan is provided on each machine side whose suction chamber is separated by a partition from the overhang space, said cap having an end on the partition side which includes an opening connected to said ducts, whereby cooling gas enters said ducts from said overhang space, and exits through the opening provided in said cap and thereafter leads directly into the suction chamber of the fan and wherein said end portion of said at least one winding bar is cooled as cooling gas travels through said ducts.