# US 6,720,687 B2 · Wake reduction structure for enhancing cavity flow in generator rotor endwindings > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,720,687 B2 - Document ID: US6720687B2 - Status: Granted - Kind: B2 - Application number: 09/742,281 - Filed: 2000-12-22 - Published: 2002-06-27 - Granted: 2004-04-13 - Earliest claimed: 2000-12-22 - Assignees: General Electric Company - Inventors: Samir Armando Salamah; Todd Garrett Wetzel; Christian Lee Vandervort; Emil Donald Jarczynski; Wayne Nigel Owen Turnbull - Web page: https://patentgrep.com/patent/US6720687B2 ## CPC - H02K 3/51: applicable to rotors only - H02K 3/24: with channels or ducts for cooling medium between the conductors - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A gas cooled dynamoelectric machine is provided that is comprised of a rotor, a rotor winding comprising axially extending coils and concentric endwindings, and a plurality of spaceblocks located between adjacent endwindings thereby to define a plurality of cavities, each bounded by adjacent spaceblocks and adjacent endwindings. To enhance the heat transfer rate from the copper end turns of the field endwinding region, at least one spaceblock has a trailing edge or downstream wall contoured to reduce generated wake. In a preferred embodiment, the trailing edge has an aerodynamic contour to reduce the extent and strength of the generated wake. ## Claims ### Claim 1 A gas cooled dynamoelectric machine, comprising: a rotor having a body portion, said rotor having axially extending coils and end turns defining a plurality of endwindings extending axially beyond at least one end of said body portion; and at least one spaceblock located between adjacent said endwindings so as to define a cavity therebetween, said spaceblock having first and second sidewall portions engaging said adjacent endwindings, an upstream wall, and a downstream wall, said downstream wall of said spaceblock having a convexly curved, aerodynamic contour for reducing the extent and strength of the generated wake. ### Claim 2 (depends on 1) The dynamoelectric machine of claim 1, wherein said downstream wall is defined as a generally parabolic curve. ### Claim 3 (depends on 1) The dynamoelectric machine of claim 1, wherein said upstream wall is generally planar. ### Claim 4 (depends on 1) The dynamoelectric machine of claim 1, wherein said spaceblock is comprised of a generally rectangular main body portion and a protrusion portion, said main body portion defining said upstream wall and said sidewall portions, and said protrusion portion defining said downstream wall. ### Claim 5 (depends on 4) The dynamoelectric machine of claim 4, wherein said downstream wall is defined as a generally parabolic curve. ### Claim 6 (depends on 4) The dynamoelectric machine of claim 4, wherein said upstream wall is generally planar. ### Claim 7 (depends on 4) The dynamoelectric machine of claim 4, wherein said protrusion portion is integrally formed with said main body portion. ### Claim 8 A gas cooled dynamoelectric machine, comprising: a rotor having a spindle and a body portion; a rotor winding comprising axially extending coils disposed on said body portion and spaced, concentric endwindings extending axially beyond at least one end of said body portion, said endwindings and said spindle defining an annular space therebetween; a plurality of spaceblocks located between adjacent ones of said endwindings thereby to define a plurality of cavities, each bounded by adjacent spaceblocks and adjacent endwindings and open to said annular space; and each said spaceblock having first and second sidewall portions engaging said adjacent endwindings, an upstream wall, and a downstream wall, said downstream wall of at least one of said spaceblocks having convexly curved, aerodynamic contour for reducing the extent and strength of the generated wake. ### Claim 9 (depends on 8) The dynamoelectric machine of claim 8, wherein said non-planar downstream wall is defined as a generally parabolic curve. ### Claim 10 (depends on 8) The dynamoetectric machine of claim 8, wherein said upstream wall of each said spaceblock is generally planar. ### Claim 11 (depends on 8) The dynamoelectric machine of claim 8, wherein said at least one spaceblock is comprised of a generally rectangular main body portion and a protrusion portion, said main body portion defining said upstream wall and said sidewall portions, and said protrusion portion defining said convexly curved, aerodynamic downstream wall. ### Claim 12 (depends on 11) The dynamoelectric machine of claim 11, wherein said downstream wall is defined as a generally parabolic curve. ### Claim 13 (depends on 11) The dynamoelectric machine of claim 11, wherein said upstream wall is generally planar. ### Claim 14 (depends on 11) The dynamoelectric machine of claim 11, wherein said protrusion portion is integrally formed with said main body portion. ### Claim 15 (depends on 1) The dynamoelectric machine of claim 1, further comprising a rotor spindle extending axially beyond said at least one end of said body portion and defining an annular space with said endwindings, and wherein said at least one spaceblock extends radially into said annular space. ### Claim 16 (depends on 8) The dynamoelectric machine of claim 8, wherein said plurality of spaceblocks extend radially into said annular space.