Fuel transfer system for multiple concentric shaft gas turbine engines

Claim 1

A fuel pumping and transfer system for a turbine engine having a combustion region, said fuel system comprising: a housing; a first spool having an inner shaft rotatably mounted to said housing, said inner shaft having at least one discharge hole and an inner surface defining a central bore; a fuel tube extending axially within said central bore and mounted to said inner shaft for rotation with said inner shaft, said fuel tube having a first end and a second end, said second end of said pair of ends being adjacent said at least one discharge hole; means for supplying fuel to said fuel tube, said means for supplying in flow communication with said first end of said fuel tube, said fuel tube delivering said fuel to said second end of said fuel tube by centrifugal force when said inner shaft is rotated; means for discharging fuel from said second end of said fuel tube through said at least one discharge hole of said inner shaft, said means for discharging comprising a baffle mounted opposite said second end of said fuel tube and a dam extending radially inwardly from said inner surface of said inner shaft, said dam disposed intermediate said at least one discharge hole and said baffle whereby a ring of fuel is trapped by said dam is increase the pressure of said fuel prior to being discharged through at least one discharge hole; a second spool rotatably mounted to said housing, said second spool independently rotatable with respect to said inner shaft and having an outer shaft extending coaxially with and spaced apart from said inner shaft, said outer shaft having a collector dam mounted to said outer shaft and extending radially inwardly from said outer shaft, said collector dam having an elongated portion extending opposite said at least one of discharge hole of said inner shaft whereby said collector dam collects fuel discharged from said at least one discharge hole; and means for transferring fluid collected by said collector dam of said outer shaft to said combustion region of said turbine engine, said transferring means comprising a collection housing and a plurality of slinger discharge passageways formed in said outer shaft whereby fuel from said collector dam is communicated to said collector housing and expelled through said plurality of slinger passageways by centrifugal force.