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US 9,617,994 B2Granted
Pump with mechanical seal assembly
AssigneeDelaware Capital Formation, Inc.
InventorsMichael Douglas Walters, Michael Thomas Mitchell
Life of this patent
Estimating the term…
Abstract
A sliding vane, positive displacement pump is provided which includes a dual mechanical seal that protects against leakage from a pump chamber while also reducing slip across rotor end faces. The dual mechanical seal may be formed as a cartridge seal that is readily demountable from the pump for replacement and service, and is retrofittable to existing pumps to improve the performance thereof. The pump may integrally include a dual mechanical seal, or the mechanical seal assembly may be provided for use by itself or in combination with a replaceable head ring that can be installed on existing pumps for repair thereof or for a retrofit upgrade of such existing pump.
Claims25
A pump, comprising:
- a pumping assembly comprising a casing which defines a pump chamber having at least one open end, a rotatable shaft entering said pump chamber through said open end, and a rotor within said pump chamber having a rotor end face which faces said open end, said rotor being rotatably driven by said shaft to effect pumping of a process fluid, said pump assembly further including at least one head ring mounted to said casing to partially enclose said open end of said pump chamber, said head ring including a head bore which receives said shaft therethrough, and said head bore being defined by an inner bore surface spaced radially outwardly of an outer shaft surface to define a seal pocket which opens towards said rotor end face;
- and
- a mechanical seal assembly comprising:
- a rotatable sealing ring which is rotatably mounted on said shaft for rotation therewith, said rotatable sealing ring being disposed within said seal pocket of said head bore with an inboard first ring surface disposed in axial facing contact with said rotor end face, said rotatable sealing ring having an opposite, outboard second ring surface facing away from said rotor and defining at least a first rotating sealing face;
- a seal housing mounted to said pumping assembly;
- at least a first stationary sealing ring which is non-rotatably mounted to said seal housing and defines a first stationary sealing face disposed in opposed, sealing engagement with said first rotating sealing face, said first rotating and stationary sealing faces defining a first sealing region which sealingly separates first and second fluid chambers respectively containing a first fluid and a pressurized second fluid at a pressure greater than said first fluid, said pressurized second fluid acting on said rotating sealing ring to axially bias said rotating sealing ring into contact with said rotor end face to reduce slip of said process fluid across said rotor end face.
3 more elements
An assembly of pump components, comprising:
- a head ring having a mounting flange mountable to a casing of a pump to partially enclose an open end of a pump chamber, said head ring including a head bore for receiving a pump shaft therethrough, said head bore being defined by an inner bore surface having a diameter greater than a diameter of a pump shaft wherein said pump bore defines a seal pocket which opens in an inboard direction so as to open toward a pump chamber when said head ring is mounted to a pump and which also opens in an outboard direction;
- and
- a mechanical seal assembly comprising:
- a seal housing having a mounting flange removably mounted to said head ring;
- a drive collar mountable to a pump shaft for rotation therewith;
- a rotatable sealing ring which is mounted on an inboard collar end of said drive collar for rotation therewith, said inboard collar end and said rotatable sealing ring being disposed within said seal pocket of said head bore with an inboard first ring surface facing axially in said inboard direction, said drive collar and said rotatable sealing ring being slidably axially within said head bore, and said rotatable sealing ring having an opposite, outboard second ring surface facing in said outboard direction and defining at least a first rotating sealing face;
- and
- at least a first stationary sealing ring which is non-rotatably mounted to said seal housing and defines a first stationary sealing face disposed in opposed, sealing engagement with said first rotating sealing face, said first rotating and stationary sealing faces defining a first sealing region for sealingly separating first and second fluid chambers, said second fluid chamber opening toward said outboard second ring surface of said rotating sealing ring to permit pressurized fluid in said second fluid chamber to bias said rotating sealing ring axially in said inboard direction, said inboard first ring surface of said rotatable sealing ring projecting from said head ring for contact with a rotor end face in a pump bore.
5 more elements
A mechanical seal assembly comprising:
- a seal housing having a mounting flange which is removably mountable to an equipment housing;
- a drive collar mountable to a shaft for rotation therewith, said drive collar including a mounting flange which is located on an inboard collar end, said inboard collar end terminating at a collar end face which faces in an inboard direction, and said mounting flange projecting radially outwardly;
- a rotatable sealing ring which is mounted on said inboard collar end for rotation therewith, said rotatable sealing ring having an inboard first ring surface facing axially in said inboard direction, said rotatable sealing ring being slidable axially in the inboard direction relative to said mounting flange so that said inboard first ring surface and said collar end face are locatable in a common plane, said rotatable sealing ring having an opposite, outboard second ring surface facing away from said rotor in an outboard direction and defining first and second rotating sealing faces wherein said first and second rotating sealing faces are disposed in radially spaced concentric relation;
- and
- concentric, radially spaced, first and second stationary sealing rings which are non-rotatably mounted to said seal housing and define respective first and second stationary sealing faces, disposed in opposed, sealing engagement with said first and second rotating sealing faces, said first rotating and stationary sealing faces defining a first sealing region for sealingly separating first and second fluid chambers, and said second rotating and stationary sealing faces defining a second sealing region for sealingly separating said second fluid chamber and a third fluid chamber, said second fluid chamber opening toward said outboard second ring surface of said rotating sealing ring to permit pressurized fluid in said second fluid chamber to bias said rotating sealing ring axially in said inboard direction.
2 more elements
Dependencies are inferred from the claim text.