Pressurized chamber seal cartridge
AssigneeAV Cell Inc.
InventorJames Daniel Murray
Life of this patent
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Abstract
A seal cartridge for a centrifugal pump includes a housing that fits within a conventional stuffing box of the pump and has a cylindrical internal surface receiving the shaft. A pair of annular grooves are provided internally of the housing adjacent respectively opposite ends thereof. Each groove receives an O-ring that runs in contact with the sleeve when the shaft rotates. The sleeve, housing and O-rings define an annular chamber through which water is circulated to cool and lubricate the O-rings. The water is pressurized to cause the O-rings to deform and seal against the sleeve.
Claims14
A seal assembly for a rotary shaft having a surface speed higher than 200 ft/min. the seal assembly comprising:
- a housing having a generally cylindrical internal surface receiving the shaft, said internal surface including first and second internal annular grooves spaced longitudinally of and encircling said internal surface;
- an O-ring disposed in each groove and in contact with the external surface of the shaft and against which the shaft rotates in use;
- inlet and outlet ports for a cooling fluid extending through the housing into said generally cylindrical internal surface of the housing at locations spaced angularly about the housing and between said O-rings, whereby an annular chamber is defined between the shaft and the housing intermediate the two O-rings, through which a cooling fluid is circulated in use via said ports;
- and means for creating a positive cooling fluid pressure within said chamber;
- the O-rings being deformable under said pressure to seal against the rotary shaft.
A method of sealing a rotary shaft against fluid leakage along the shaft, wherein the shaft rotates at a surface speed higher than 200 ft/min and wherein the method comprises the steps of:
- providing a seal assembly comprising:
- a housing having a generally cylindrical internal surface which receives the shaft and which includes first and second internal annular grooves spaced longitudinally of and encircling the housing;
- an O-ring disposed in each groove and in contact with the external surface of the shaft and against which the shaft rotates in use;
- and an annular chamber defined between the shaft and the housing intermediate the two O-rings;
- and,
- circulating a cooling fluid through said annular chamber under pressure to cause the O-rings to deform and seal against the rotary shaft.
A method of sealing a rotary drive shaft of a centrifugal pump against fluid leakage along the shaft, the method comprising the steps of:
- providing a seal assembly comprising:
- a housing having a generally cylindrical internal surface which receives the shaft and which includes first and second internal annular grooves spaced longitudinally of and encircling the housing;
- an O-ring disposed in each groove and in contact with the external surface of the shaft and against which the shaft rotates in use;
- and an annular chamber defined between the shaft and the housing intermediate the two O-rings;
- rotating said shaft at a linear surface speed in a range from 200 ft/min to 4,713 ft/min;
- and,
- circulating a cooling fluid through said annular chamber under pressure to cause the O-rings to deform and seal against the rotary shaft.
Dependencies are inferred from the claim text.