Pitot pump with thrust balance

Claim 2

In a pitot pump adapted to pump a fluid, the combination of: a rotary casing rotatable about a central axis, and including an annular pump chamber; an outer housing surrounding said rotary casing, said outer housing having an inlet port and a discharge port; drive shaft means extending into one end of said housing and rigidly connected to said casing, said drive shaft means having a cylindrical shaft extension extending into said pump chamber and concentric with the axis thereof; bearing means between said drive shaft means and said housing; and generally tubular means extending longitudinally in said housing and upon which said casing is mounted for rotation, such tubular means being fixedly mounted on said housing and having an inlet passage therein communicating between said inlet port and said chamber for supply of a fluid to be pumped in said chamber, said tubular means having a pitot tube fixedly mounted thereon and extending radially in said chamber, said pitot tube having adjacent its outer end a pitot inlet facing in a direction opposite to the direction of rotation of said casing and a passage therein communicating between said pitot inlet and a longitudinal discharge passage in said tubular member, in turn communicating with said outlet, said tubular means having a cylindrical tubular extension journalling said cylindrical shaft extension of said drive shaft means, the maximum effective cross-sectional area of said tubular means in said chamber being approximately equal to the maximum effective cross-sectional area of said cylindrical shaft extension so that the fluid pressure in said chamber bears on substantially equal exposed chamber areas on said casing and on said tubular means, and means for venting said cylindrical tubular extension to a pressure much lower than that in said chamber, and approaching atmospheric pressure, so that there is substantially no net fluid force tending to move said casing axially relative to said housing to overload said bearing means.

Claim 3

In a pitot pump adapted to pump a fluid, the combination of: a rotary casing rotatable about a central axis, and including an annular pump chamber; an outer housing surrounding said rotary casing, said outer housing having an inlet port and a discharge port; drive shaft means extending into one end of said housing and rigidly connected to said casing, said drive shaft means having a cylindrical shaft extension extending into said pump chamber and concentric with the axis thereof; bearing means between said drive shaft means and said housing; generally tubular means extending longitudinally in said housing and upon which said casing is mounted for rotation, such tubular means being fixedly mounted on said housing and having an inlet passage therein communicating between said inlet port and said chamber for supply of a fluid to be pumped to said chamber, said tubular means having a pitot tube fixedly mounted thereon and extending radially in said chamber, said pitot tube having adjacent its outer end a pitot inlet facing in a direction opposite to the direction of rotation of said casing and a passage therein communicating between said pitot inlet and a longitudinal discharge passage in said tubular member, said longitudinal discharge passage in turn communicating with said outlet, said tubular means having a cylindrical tubular extension journalling said cylindrical shaft extension of said drive shaft means, the maximum effective cross-sectional area of said tubular means in said chamber being approximately equal to the maximum effective cross-sectional area of said cylindrical sleeve so that the fluid pressure in said chamber bears on substantially equal exposed chamber areas on said casing and on said tubular means; and An exhaust duct in said tubular means communicating between the interior of said cylindrical tubular extension and said inlet passage, the periphery of said cylindrical shaft extension and the interior of said cylindrical tubular extension having a small clearance therebetween permitting a small flow of fluid from said chamber through said clearance to lubricate the same, said flow being conducted through said exhaust duct into said inlet passage so that there is substantially no net fluid force tending to move said casing axially relative to said housing to overload said bearing means.

Claim 4

In a pitot pump adapted to pump a fluid, the combination of: a rotary casing rotatable about a central axis, and including an annular pump chamber; an outer housing surrounding said rotary casing, said outer housing having an inlet port and a discharge port; drive shaft means extending into one end of said housing and rigidly connected to said casing, said drive shaft means having a cylindrical shaft extension extending into said pump chamber and concentric with the axis thereof; bearing means between said drive shaft means and said housing; generally tubular means extending longitudinally in said housing and upon which said casing is mounted for rotation, such tubular means being fixedly mounted on said housing and having an inlet passage therein communicating between said inlet port and said chamber for supply of a fluid to be pumped to said chamber, said tubular means having a pitot tube fixedly mounted thereon and extending radially in said chamber, said pitot tube having adjacent its outer end a pitot inlet facing in a direction opposite to the direction of rotation of said casing and a passage therein communicating between said pitot inlet and a longitudinal discharge passage in said tubular member, said longitudinal discharge passage in turn communicating with said outlet, said tubular means having a cylindrical tubular extension journalling said cylindrical shaft extension of said drive shaft means, the maximum effective cross-sectional area of said tubular means in said chamber being approximately equal to the maximum effective cross-sectional area of said cylindrical sleeve so that the fluid pressure in said chamber bears on substantially equal exposed chamber areas on said casing and on said tubular means; and An exhaust duct in said tubular means communicating between the interior of said cylindrical tubular extension and said inlet passage, the periphery of said cylindrical shaft extension and the interior of said cylindrical tubular extension having a small clearance therebetween permitting a small flow of fluid from said chamber through said clearance to lubricate the same, said flow being conducted through said exhaust duct into said inlet passage so that there is substantially no net fluid force tending to move said casing axially relative to said housing to overload said bearing means.

Claim 5

In a pitot pump adapted to pump a fluid, the combination of: a generally cylindrical rotary casing rotatable about its central axis, including an annular pump chamber; an outer housing surrounding said rotary casing, said outer housing having an inlet port and a discharge port; drive shaft means extending into one end of said housing and rigidly connected to said casing, said drive shaft means having a first cylindrical bearing member extending into said pump chamber and concentric with the axis thereof; bearing means between said drive shaft means and said housing; generally tubular means extending longitudinally in said housing and upon which said casing is mounted for rotation, such tubular means being fixedly mounted on said housing and having an inlet passage therein communicating between said inlet port and said chamber for supply of a fluid to be pumped to said chamber, said tubular means having a pitot tube fixedly mounted thereon and extending radially in said chamber, said pitot tube having adjacent its outer end a pitot inlet facing in a direction opposite to the direction of rotation of said casing and a passage therein communicating between said pitot inlet and a longitudinal discharge passage in said tubular member which, in turn, communicates with said outlet, said tubular means having a second cylindrical bearing member in journalled relation with said first cylindrical bearing member, the maximum effective cross-sectional area of said tubular means in said chamber being approximately equal to the maximum effective cross-sectional area of said first bearing member so that the fluid pressure in said chamber bears on substantially equal exposed chamber areas on said casing and on said tubular means; said bearing members having a small clearance therebetween permitting small leakage flow of fluid from said chamber through said clearance to lubricate said bearing members; and an exhaust duct in said tubular means for conducting said leakage flow into said inlet passage so that there is substantially no net fluid force tending to move said casing axially relative to said housing to overload said bearing means.

Claim 6

In a pitot pump adapted to pump a fluid, the combination of: a generally cylindrical rotary casing rotatable about its central axis, including an annular pump chamber; an outer housing surrounding said rotary casing, said outer housing having an inlet port and a discharge port; drive shaft means extending into one end of said housing and rigidly connected to said casing, said drive shaft means having a first cylindrical bearing member extending into said pump chamber and concentric with the axis thereof; bearing means between said drive shaft means and said housing; generally tubular means extending longitudinally in said housing and upon which said casing is mounted for rotation, such tubular means being fixedly mounted on said housing and having an inlet passage therein communicating between said inlet port and said chamber for supply of a fluid to be pumped to said chamber, said tubular means having a pitot tube fixedly mounted thereon and extending radially in said chamber, said pitot tube having adjacent its outer end a pitot inlet facing in a direction opposite to the direction of rotation of said casing and a passage therein communicating between said pitot inlet and a longitudinal discharge passage in said tubular member which, in turn, communicates with said outlet, said tubular means having a second cylindrical bearing member in journalled relation with said first cylindrical bearing member, the maximum effective cross-sectional area of said tubular means in said chamber being approximately equal to the maximum effective cross-sectional area of said first bearing member so that the fluid pressure in said chamber bears on substantially equal exposed chamber areas on said casing and on said tubular means; said bearing members having a small clearance therebetween permitting small leakage flow of fluid from said chamber through said clearance to lubricate said bearing members; and an exhaust duct in said tubular means for conducting said leakage flow into said inlet passage so that there is substantially no net fluid force tending to move said casing axially relative to said housing to overload said bearing means.