Wells – Above ground apparatus – With seal for reciprocating member
Utility Patent
1998-11-09
2001-01-02
Dang, Hoang (Department: 3672)
Wells
Above ground apparatus
With seal for reciprocating member
C166S084400, C277S329000
Utility Patent
active
06167959
ABSTRACT:
FIELD OF THE INVENTION
The present invention pertains to adjustable stuffing boxes and seal assemblies for cylindrical shafts or rods, particularly well pump rods.
BACKGROUND
A longstanding problem in the well pumping industry pertains to providing a suitable seal around the reciprocating pump rod or so-called “polished” rod section of an elongated down-hole pump rod string. This problem is found to exist also in connection with downhole rotary pumps and rotary drive shaft seals therefor. In rod actuated well pump systems, the upper end of the elongated rod string which is connected to a pump actuating mechanism or so-called pump-jack is typically exposed to the ambient environment extremes and must operate for long periods of time unattended due to the remote location of many well pumps. However, the seal assembly that surrounds the polished rod section of the pump rod string, sometimes commonly referred to as a stuffing box, is a critical element to prevent unwanted discharge of well fluids from the wellhead at the point of entry of the rod string.
Several efforts have been undertaken to develop improvements in pump rod stuffing boxes. U.S. Pat. Nos. 5,343,944; 5,538,080 and 5,636,688 and copending U.S. patent application Ser. No. 09/024,738 filed Feb. 17, 1998, now U.S. Pat. No. 6,000,469 all to Grey Bassinger and U.S. Pat. No. 5,803,169 issued Sep. 8, 1998 to Grey Bassinger and Joseph L. Dalton, all assigned to the assignee of the present invention, represent improvements in stuffing boxes for well pump rods. However, certain applications for stuffing boxes for well pumps do not require the self-aligning features of the above-mentioned patents and patent application, may have a shorter service life by design, or, for various reasons, do not require the features of the inventions of the above-referenced patents and patent application. Moreover, virtually all applications for well pump stuffing boxes require simplicity of stuffing box design, reliability in operation, unattended operation for long periods of time, and ease of adjustment and/or replacement or repair of the stuffing box components when an attendant is present to service the stuffing box. Accordingly, features which are desirable in pump rod stuffing boxes include automatic adjustment of the packing to compensate for wear thereof, a suitable cavity for lubricant to lubricate certain movable parts in the stuffing box, providing for pressure forces acting to compress the packing which correspond to or are proportional to fluid pressure forces against which the packing is providing a seal, ease of adjustment of the forces acting on the packing as provided by a packing gland, indexible parts which are subject to wear from lateral deflection of the pump rod, ease of repair and adjustment and a temporary seal or pack-off feature to prevent well fluids from flowing, under pressure, into the stuffing box during partial disassembly and repair or packing replacement.
The present invention provides the desiderata mentioned above as well as solving other problems in the art of adjustable stuffing boxes for reciprocating pump rods and the like.
SUMMARY OF THE INVENTION
The present invention provides an improved adjustable stuffing box, particularly adapted for providing a seal for a pump shaft or rod for downhole well pumps and the like.
In accordance with one important aspect of the present invention, a stuffing box for a reciprocating pump rod is provided which includes a packing gland which may be adjusted at will and may be rotatably indexed to compensate for wear generated by lateral deflection of the pump rod.
In accordance with another important aspect of the invention, a slidable bushing is disposed in the stuffing box and acts against the packing under the urging of spring forces as well as fluid pressure forces to compensate for wear on the packing, to increase forces acting on the packing proportional to fluid pressure forces acting on the stuffing box and to extend the interval or operating time before adjustment of the packing gland is required.
In accordance with still another aspect of the invention, a stuffing box is provided which includes a housing supporting a slidable bushing acting on the stuffing box packing under the urging of spring forces and fluid pressure forces and which is disposed partially in a neutral pressure cavity which may contain a lubricant to lubricate the bushing and seals therefor. The stuffing box packing is also disposed between the spring and fluid pressure force biased packing adjustment bushing and a packing gland and also functions as a bushing or bearing to minimize wear on the gland and adjustment bushing due to any lateral deflection of the rod.
In accordance with yet another aspect of the present invention, an adjustable stuffing box for a well pump rod and the like is provided wherein during adjustment, repair or replacement of stuffing box parts, a so-called pack-off or temporary seal element may be activated to prevent pressure fluid from entering the stuffing box from the wellbore or associated wellhead structure.
The present invention also provides a stuffing box and seal assembly adapted for use with a rotary pump shaft or rod for driving a downhole well pump and the like and which enjoys the benefits and advantages of the invention described hereinabove. Still further, the improved rotary shaft stuffing box of the invention is advantageously provided with a packing coolant flow circuit.
The present invention provides adjustable stuffing boxes for pump rods and the like which meet the desiderata mentioned hereinabove and solve problems associated with pump rod or shaft seal stuffing boxes in a manner heretofore unappreciated in the art. Those skilled in the art will recognize the above-mentioned superior features and advantages of the present invention together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawing.
REFERENCES:
patent: 1911670 (1933-05-01), Black
patent: 1947198 (1934-02-01), Goble
patent: 2048320 (1936-07-01), Bennett
patent: 2069443 (1937-02-01), Hill
patent: 2159306 (1939-05-01), Winters
patent: 2179814 (1939-11-01), Conaghan
patent: 2182246 (1939-12-01), Boyer et al.
patent: 2219064 (1940-10-01), Boyer et al.
patent: 2567479 (1951-09-01), Hebard
patent: 2628112 (1953-02-01), Hebard
patent: 2721748 (1955-10-01), Tremolada
patent: 3244424 (1966-04-01), Cope
patent: 3395923 (1968-08-01), Remke et al.
patent: 3468374 (1969-09-01), Reeves
patent: 3512787 (1970-05-01), Kennedy et al.
patent: 3675933 (1972-07-01), Nappe
patent: 3722894 (1973-03-01), Cameron-Johnson
patent: 3886804 (1975-06-01), Winfield, Jr.
patent: 3887196 (1975-06-01), Renfrow
patent: 4008897 (1977-02-01), Wentworth
patent: 4320799 (1982-03-01), Gilbertson
patent: 4345766 (1982-08-01), Turanyi
patent: 4490097 (1984-12-01), Gilbertson
patent: 4560176 (1985-12-01), Hoff
patent: 4907650 (1990-03-01), Heinonen
patent: 4981174 (1991-01-01), White
patent: 5067563 (1991-11-01), Rode
patent: 5137083 (1992-08-01), Bump
patent: 5343944 (1994-09-01), Bassinger
patent: 5538080 (1996-07-01), Bassinger
patent: 5636688 (1997-06-01), Bassinger
patent: 5803169 (1998-09-01), Bassinger et al.
Bassinger Grey
Dalton, III Joseph L.
Akin Gump Strauss Hauer & Feld L.L.P.
Auto Pax Products, L.L.C.
Dang Hoang
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