AXIAL COOLING OF A ROTOR

• US 20020047412A1
• Filed: 06/28/1999
• Published: 04/25/2002
• Est. Priority Date: 11/04/1996
• Status: Active Grant

• Current Assignee: Asea Brown Boveri AB (ABB Limited)
• Original Assignee: Asea Brown Boveri AB (ABB Limited)
• Inventors: LEIJON, MATS, KYLANDER, GUNNAR
• Granted Patent: US 6,369,470 B1
• Time in Patent Office: Days
• US Class Current: 310/104
• CPC Class Codes: H02K 1/325 between salient poles

Abstract

A rotating electric machine (1) having a stator (2) provided with windings and a rotor (4) provided with windings and with salient poles (10) forming pole gaps (9) between the pole shoes (12) of the poles (10), which rotor (4) is arranged to be cooled by air flowing axially through the pole gaps (9) of the rotor (4), wherein each pole gap (9) between the pole shoes (12) is covered by at least one covering member (14) and that the air gap (15) is equipped with a sealing ring (16) to limit axial air flow.

Claims

1. A rotating electric machine (1) having a stator (2) provided with windings and a rotor (4) provided with field windings and with salient poles (10) forming pole gaps (9) between the pole shoes (12) of the poles (10), which rotor (4) is arranged to be cooled by air flowing axially through the pole gaps (9) of the rotor (4), characterized in that each pole gap (9) between the pole shoes (12) is covered by at least one covering member (14) and that the air gap (15) is equipped with an air choke (16) to limit axial air flow.

2. A machine as claimed in claim 1, characterized in that the rotor (4) is provided with at least one fixed sealing ring (16) arranged around the rotor (4) in the air gap (15) between stator (2) and rotor (4).

3. A machine as claimed in claim 1, characterized in that the stator (2) is provided with at least one internally fixed sealing ring (16) arranged around the stator (2) in the air gap (15) between stator (2) and rotor (4).

4. A machine as claimed in either of claims 2-3, characterized in that the sealing ring (16) is placed on the air-inlet side of the machine (1).

5. A machine as claimed in any of the preceding claims, characterized in that the cooling air flow is arranged to be achieved by means of a fan (8) connected to the rotor (4).

6. A machine as claimed in any of the preceding claims, characterized in that the cover member (14) is divided or perforated at the axial centre of the rotor (4) so that the air can be deflected from its axial direction to a radial direction out through an air duct in the stator (2).

7. A machine according to any of the preceding claims, characterized in that the stator winding (3) consists of high-voltage cable.