Gas turbine engine internal lubricant sump venting and pressurization system

Claim 2

In a gas turbine engine of the type including at least first and second compressor portions and first and second turbine portions; at least two concentric, hollow shaft assemblies operatively connecting certain of said compressor portions to certain of said turbine portions; a plurality of bearing assemblies adapted to rotatably support said shaft assemblies; casing means enclosing portions of said compressors and said turbines, said casing means adapted to define, at least in part, a generally annular motive flow passage therethrough having an inlet upstream of at least one of said compressor portions and an outlet downstream of at least one of said turbine portions; said casing means further defining, in cooperation with at least one of said shaft assemblies, a first bearing chamber and at least a second axially spaced bearing chamber, said bearing chambers adapted to enclose said bearing assemblies and receive a lubricating fluid; a plurality of seal pressurization chambers, at least one of which is associated with each said bearing chamber; means for delivering air into said seal pressurization chambers; means for venting said bearing chambers to establish a continuous flow of air through said bearing chambers; and means for scavenging said lubricating fluid from said bearing chambers; the improvement comprising: said air delivery means and said scavenge means for at least a first of said bearing chambers being formed internally of at least one of said shaft assemblies such that the air delivery and scavenge functions may be accomplished for said first bearing chamber without the necessity of piping extending across said annular motive flow passage or piping mounted externally of said engine; and wherein said air delivery means comprise a bleed port located intermediate of one of said compressor portions, a bleed chamber formed internally of said compressor portion, and at least two flow paths extending from said bleed chamber, the first said flow path comprising a seal pressurization flow path and the second said flow path comprising a compressor coolant flow path.

Claim 3

The improved gas turbine engine recited in claim 1 further characterized in that said seal pressurization flow path comprises, in part, an annular seal pressurization passageway formed withiN one of said shaft assemblies and extending from said bleed chamber to one of said bearing chambers, and said scavenge means includes a scavenge passageway formed within one of said shaft assemblies, said scavenge passageway extending from one of said bearing chambers to a second of said bearing chambers.

Claim 4

The improved gas turbine engine recited in claim 2 further characterized in that said venting means include an annular vent passage formed internally of one of said shaft assemblies.

Claim 5

The improved gas turbine engine recited in claim 3 further characterized in that said seal pressurization flow path and said compressor coolant flow path are maintained separate from one another after the air exits said bleed chamber.

Claim 6

The improved gas turbine engine recited in claim 4 further including a third flow path from said bleed chamber, said third flow path comprising a seal pressurization flow path for at least said upstream bearing chamber while said first flow path forms a seal pressurization flow path for a downstream bearing chamber.

Claim 7

The improved gas turbine engine recited in claim 5 further characterized in that said engine includes at least three of said bearing chambers, and said third flow path comprises a seal pressurization flow path for at least two of said bearing chambers.

Claim 8

A gas turbine engine including, in combination: a first and second compressor and a first and second turbine arranged in serial flow relation; concentric inner and outer hollow shaft assemblies operatively connecting, respectively, a portion of said first compressor with a portion of said second turbine and a portion of said second compressor with a portion of said first turbine; core engine casing means enclosing at least said second compressor and said turbines, said casing means adapted to define, at least in part, a generally annular motive flow passage therethrough having an inlet upstream of at least said second compressor and an outlet downstream of said second turbine; bearing means carried by said casing means at at least three axially spaced locations for rotatably supporting said shafts; said casing means further defining, in cooperation with at least one of said shaft assemblies, a bearing chamber at each of said three locations adapted to enclose said bearing means and receive a lubricating fluid, means for supplying lubricating fluid to said bearing chambers, the upstream one of said bearing chambers disposed adjacent the upstream end of said inner shaft assembly, another of said bearing chambers disposed adjacent the upstream end of said outer shaft assembly and another bearing chamber disposed downstream of said intermediate bearing chamber; a plurality of seal pressurization chambers, at least one of which is associated with each said bearing chamber; a central scavenge passage formed internally of said inner shaft assembly and adapted to fluidically connect said downstream bearing chamber to said intermediate bearing chamber, means for delivering lubricating fluid from said downstream bearing chamber to said intermediate bearing chamber, and means for scavenging lubricating fluid from said intermediate bearing chamber; means for pressurizing each of said seal pressurization chambers, said pressurizing means including a bleed port located intermediate of said second compressor, a bleed chamber lying in fluid flow communication with said port, an annular passageway formed, in part, by said outer shaft assembly, which passageway lies in fluid flow communication with said bleed chamber and is adapted to deliver pressurizing air from said bleed port to at least one said seal pressurization chamber associated with said downstream bearing chamber such that said downstream bearing chamber may be both pressurized and scavenged without the need for piping mounted externally of said casing means or piping extending across said annular motive flow passage downstream of said second turbine; and a coolant flow path extending from said bleed chamber to providE pressurized air for cooling a portion of said second compressor, said coolant flow path maintained separate from the seal pressurization flow path after the air exits said bleed chamber.

Claim 9

A gas turbine engine including, in combination: a first and second compressor and a first and second turbine arranged in serial flow relation; concentric inner and outer hollow shaft assemblies operatively connecting, respectively, a portion of said first compressor with a portion of said second turbine and a portion of said second compressor with a portion of said first turbine; core engine casing means enclosing at least said second compressor and said turbines, said casing means adapted to define, at least in part, a generally annular motive flow passage therethrough having an inlet upstream of at least said second compressor and an outlet downstream of said second turbine; bearing means carried by said casing means at at least three axially spaced locations for rotatably supporting said shafts; said casing means further defining, in cooperation with at least one of said shaft assemblies, a bearing chamber at each of said three locations adapted to enclose said bearing means and receive a lubricating fluid, means for supplying lubricating fluid to said bearing chambers, the upstream one of said bearing chambers disposed adjacent the upstream end of said inner shaft assembly, another of said bearing chambers disposed adjacent the upstream end of said outer shaft assembly and another bearing chamber disposed downstream of said intermediate bearing chamber; a plurality of seal pressurization chambers, at least one of which is associated with each said bearing chamber; a central scavenge passage formed internally of said inner shaft assembly and adapted to fluidically connect said downstream bearing chamber to said intermediate bearing chamber, means for delivering lubricating fluid from said downstream bearing chamber to said intermediate bearing chamber, and means for scavenging lubricating fluid from said intermediate bearing chamber; means for pressurizing each of said seal pressurization chambers, said pressurizing means including a bleed port located intermediate of said second compressor, a bleed chamber lying in fluid flow communication with said port, an annular passageway formed, in part, by said outer shaft assembly, which passageway lies in fluid flow communication with said bleed chamber and is adapted to deliver pressurizing air from said bleed port to at least one said seal pressurization chamber associated with said downstream bearing chamber such that said downstream bearing chamber may be both pressurized and scavenged without the need for piping mounted externally of said casing means or piping extending across said annular motive flow passage downstream of said second turbine; and a coolant flow path extending from said bleed chamber to providE pressurized air for cooling a portion of said second compressor, said coolant flow path maintained separate from the seal pressurization flow path after the air exits said bleed chamber.

Claim 10

The gas turbine engine recited in claim 7 further including means for venting each of said bearing chambers such that a continuous flow of cool pressurizing air is circulated therethrough, said venting means for said intermediate chamber comprising an annular vent flow path formed by one of said inner and outer shaft assemblies, passage means for connecting said intermediate bearing chamber with said vent flow path, and means for venting said vent flow path overboard.

Claim 11

The gas turbine engine recited in claim 8 further characterized in that the air exiting said bleed chamber forms at least three separate flow paths, the first being said compressor coolant flow path, the second being a seal pressurization flow path for said downstream bearing chamber, and the third being a seal pressurization flow path for said intermediate bearing chamber and said upstream bearing chamber.

Claim 12

The gas turbine engine recited in claim 9 further including means for venting said seal pressurization chamber associated with said downstream bearing chamber, said downstream venting means lying in serial flow communication with said annular vent flow path.