Thermo pump-cooled generator end windings with internal cooling passages

Patent metadata

Field	Value
Publication number	US-2016149452-A1
Application number	US-201414554489-A
Country	US
Kind code	A1
Filing date	Nov 26, 2014
Priority date	Nov 26, 2014
Publication date	May 26, 2016
Grant date	—

Abstract

Rotor windings for a thermo pump-cooled generator have an internally formed cooling passage having a cooling inlet on a radial underside of the motor end winding portion and a cooling outlet on a radial upper side of the axial portion that is oriented within the generator air gap. The cooling passage in the rotor winding exhausts air from end winding portions that are circumscribed by a generator retaining ring into the generator air gap.

First claim

What is claimed is:

1 . A thermo pump-cooled generator, comprising:
a stator defining a stator bore; a rotor mounted on a rotor shaft and circumscribed within the stator bore, the rotor having an outer circumference, axial ends and axially aligned rotor winding channels radially oriented about the rotor outer circumference; an annular air gap defined between the stator bore and the rotor outer circumference; a retaining ring coupled to an axial end of the rotor outboard the annular air gap; a plurality of rotor windings having axial portions that are respectively oriented within respective rotor winding channels, circumscribed by the stator bore and the air gap, and having end winding portions extending outboard the annular air gap, circumscribed by the retaining ring; a cooling passage formed within the respective end winding portions and extending axially inboard in communication with the air gap, for exhausting air from the end winding portions that are circumscribed by the retaining ring into the air gap, the cooling passage having:
a cooling inlet on a radial underside of the respective rotor end winding facing the rotor shaft; and
a cooling outlet on a radial upper side of the respective rotor winding axial portion that is oriented within the air gap.

2 . The generator of claim 1 , the rotor windings comprising a plurality of radially stacked winding straps with radially aligned passages in communication with each other that collectively define the cooling inlet and the cooling outlet.

3 . The generator of claim 2 , the rotor windings comprising a plurality of at least three radially stacked winding straps, the lower most radially oriented strap defining intake of the cooling inlet and the upper most radially oriented strap defining exhaust of the cooling outlet.

4 . The generator of claim 3 , at least one of the winding straps defining the cooling passage that is in communication with the cooling inlet and outlet.

5 . The generator of claim 4 , the at least one winding strap having a channel formed therein that defines the cooling passage.

6 . The generator of claim 2 , at least one of the winding straps defining the cooling passage that is in communication with the cooling inlet and outlet.

7 . The generator of claim 6 , the at least one winding strap having a channel formed therein that defines the cooling passage.

8 . The generator of claim 7 , the cooling passage extending inboard the respective rotor channel beyond the cooling outlet.

9 . The generator of claim 8 , further comprising a second cooling outlet, oriented in the rotor winding axial portion inboard of the first cooling outlet, which is in communication with the cooling passage and the air gap.

10 . The generator of claim 6 , further comprising a second cooling outlet, oriented in the rotor winding axial portion inboard of the first cooling outlet, which is in communication with the cooling passage and the air gap.

11 . A method for thermo pump cooling a generator, comprising:
providing a generator having:
a stator defining a stator bore;
a rotor mounted on a rotor shaft and circumscribed within the stator bore, the rotor having an outer circumference, axial ends and axially aligned rotor winding channels radially oriented about the rotor outer circumference;
an annular air gap defined between the stator bore and the rotor outer circumference;
a retaining ring coupled to an axial end of the rotor outboard the annular air gap;
a plurality of rotor windings having axial portions that are respectively oriented within respective rotor winding channels, circumscribed by the stator bore and the air gap, and having end winding portions extending outboard the annular air gap, circumscribed by the retaining ring;
a cooling passage formed within the respective end winding portions and extending axially inboard in communication with the air gap, having a cooling inlet on a radial underside of the respective rotor end winding facing the rotor shaft, and a cooling outlet on a radial upper side of the respective rotor winding axial portion that is oriented within the air gap;
driving the generator shaft, heating air confined within the circumscribing retaining ring that is in communication with the end winding portions; and exhausting heated air from the end winding portions that are circumscribed by the retaining ring into the air gap by receiving the heated air in the cooling inlet and exhausting the heated air out of the cooling outlet into the air gap.

12 . The method of claim 11 , further comprising providing rotor windings including a plurality of radially stacked winding straps with radially aligned passages in communication with each other that collectively define the cooling inlet and the cooling outlet.

13 . A rotor winding for a thermo pump-cooled generator of the type having a stator bore, a rotor mounted on a rotor shaft and circumscribed within the stator bore, the rotor having an outer circumference, axial ends and axially aligned rotor winding channels radially oriented about the rotor outer circumference, an annular air gap defined between the stator bore and the rotor outer circumference, and a retaining ring coupled to an axial end of the rotor outboard the annular air gap, the rotor winding comprising:
an axial portion adapted for insertion into a generator rotor channel, having a radially oriented upper side for orientation within a rotor/stator bore air gap; an end winding portion coupled to the axial portion, adapted for orientation within a circumscribing retaining ring, having a radial underside facing the rotor shaft; and a cooling passage formed within the rotor winding end winding portion, and extending axially into the axial portion for communication with a rotor/stator air gap, for exhausting air from the end winding portions that are circumscribed by the retaining ring into the air gap, the cooling passage having:
a cooling inlet on the radial underside of the end winding portion of the rotor winding facing the rotor shaft; and
a cooling outlet on a radial upper side of the rotor winding axial portion that is adapted to be oriented within the air gap.

14 . The rotor winding of claim 13 , further comprising a plurality of radially stacked winding straps with radially aligned passages in communication with each other that collectively define the cooling inlet and the cooling outlet.

15 . The rotor winding of claim 14 , further comprising a plurality of at least three radially stacked winding straps, the lower most radially oriented strap defining intake of the cooling inlet and the upper most radially oriented strap defining exhaust of the cooling outlet.

16 . The rotor winding of claim 15 , at least one of the winding straps defining the cooling passage that is in communication with the cooling inlet and outlet.

17 . The rotor winding of claim 16 the cooling passage extending inboard within the axial portion beyond the cooling outlet.

18 . The rotor winding of claim 13 the cooling passage extending inboard within the axial portion beyond the cooling outlet.

Assignees

• Siemens Energy Inc

Inventors

• Garmon Michael D
• Rico Raul Ricardo

Classifications

• H02K9/04

  having means for generating a flow of cooling medium · CPC title

• H02K3/24 Primary

  with channels or ducts for cooling medium between the conductors · CPC title

• H02K9/10

  by gaseous cooling medium flowing in closed circuit, a part of which is external to the machine casing · CPC title

• H02K9/06

  with fans or impellers driven by the machine shaft · CPC title

• H02K9/08

  by gaseous cooling medium circulating wholly within the machine casing (H02K9/10 takes precedence) · CPC title