US2640434A - Cylinder liner and sleeve assembly for reciprocating pumps - Google Patents

Description

I June 2, 1953 A. LEMAN 2,540,434

CYLINDER LINER AND sLEEvE ASSEMBLY FOR RECIPROCATING PUMPS Filed June 2. 1949 Patented June 2, 1953 CYLINDER LINER AND SLEEVE ASSEMBLY FOR RECIPROCATING PUMPS Arthur L. Leman, Houston, Tex.

Application June 2, 1949, Serial No. 96,725

9 Claims.

My present invention concerns reciprocating piston pumps such as employed in the drilling of oil wells and elsewhere. More particularly it aims to provide an improved construction and arrangement for cylinder liners and sleeves for such liners and to facilitate the interchangeable installation of reduced size liners especially in high-pressure power driven pumps for deep wells.

In drilling oil Wells, the drill pipe and bit are rotated and fluid is circulated down through the. drill pipe, out through holes in the bit and then up through the annular space between the drill pipe and the wall of the drilled hole, carrying out the cuttings. As the hole becomes deeper, more joints of drill pipe are added. Each, such addition increases the resistance to fluid flow. When the pump pressure required to produce a certain rate of circulation becomes excessive, it is necessary to reduce the rate of circulation. This reduction in circulation is obtained by changing to a smaller size of piston and liner bore.

On deep wells the final size often results in a liner having a wall thickness more than four times greater than desirable for the best heat treatment and hydraulic pressure requirements. As this greatly increases th cost of an item which rapidly wears out, it is common practice to restore worn liners by welding in hardened sleeves. Re-sleeving by this welding method means that the worn liners must be transported from remote oil fields to manufacturing shops where the liner can be reworked.

My invention novelly provides for quickly restoring a worn liner by changing the sleeve in the oil field.

In the drawings illustrating by way of example one embodiment of the invention:

Figv 1 shows in horizontal section my cylinder and sleeve liner assembly operatively installed in the cylinder portion of a pump;

Fig. 2 is a similar sectional view showing the sleeve liner assembly separately on a larger scale;

Fig. 3 is an end View looking from the left at Fig. 2; and

Fig. 4 is an expanded isometric view of the sleeve liner sub-assembly unit.

In Fig. 1 there is shown a portion of a pump housing 5 including a cylinder 6 for the rod and piston assembly 1 operating through a packing box 8 on the housing.

The cylinder liner assembly or unit with which the invention is especially concerned is designated generally at Ill, this entire removable element being herein referred to as the cylinder liner or briefly as the liner. It is removably fixed as in axially spaced cylindrical seats H, H in the cylinder opening and extends between the inlet-outlet chambers l2, l2 for Which the discharge valves are seen at l3, l3. This cylinder assembly It is held in place as by a spider I 5 engaging the outer end thereof and secured as by a heavy screw 15 in the clamping head and cover plate It. The latter closes the access opening I"! at the outer end of this cylinder portion of the housing, where it is fastened in sealing position as by the anchor bolts l8.

The cylinder liner Ill, shown separately in Fig. 2, comprises an outer cylindrical shell 20 and a replaceable inner. sleeve 30. The shell 28 has at the outer end, at the right on the drawing, a retainer flange 2i engageable by the spider and clamping head l-il6 and presenting an in-facing external annular stop shoulder 22 which enters the usual recess is at the end of the cylinder opening.

Internally the shell 20 is specially constructed at each end portion. Near the outer end it is formed with an internal in-facing annular abutment or shoulder 23. At the opposite or inner end it is internally threaded as indicated at 2i desirably with a heavy duty'type of thread formation such as shown.

Further in accordance with the invention the inner removable sleeve'tll and immediately associated parts are novelly constructed and arranged for quick assembly into and removal from the shell 20. This sleeve 30 is of uniform inside diameter throughout. for sliding reception of the piston and rod unit I. The main intermediate or body portion 3| of the sleeve 30 may be of the thickness which is best for heat treatment and pressure requirements. Noting also Fig. 4, the sleeve end portions are externally reduced to provide at the outer end an out-facing annular abutment shoulder 32 and adjacent the other or inner end a similar but in-facing annular shoulder 33. The outer shoulder 32 provides for axial-thrustsupporting interlock with the shell 26, at the infacing shoulder 23 thereof. Such abutti-ve engagement may be directly between the sleeve and the shell. Generally and particularly with reduced'size sleeves such as illustrated the abuttiveinterlock is through the medium of an annular bushing or spacer and connector 35' of steel or other substantially incompressible material. This bushing has an axial extent corresponding to the spacing of the sleeve shoulder 32 from the end of the sleeve and is itself formed with an external out-facing shoulder 36 located'for' end-i 3 wise abuttive engagement by and with the shell shoulder 23.

At the opposite or inner end the sleeve 30 is positioned in coaxial parallel relation to the shell by means of a compressible packing unit designated generally at 40, Figs. 1, 2 and 4. Such unit as illustrated comprises a pair of axially spaced metal junk rings 4! at the opposite sides of a compressible annular packing mass or ring 42. This packing element 4!] is axially located on the sleeve by abutment of the inner junk ring 4! with the in-facing sleeve shoulder 33.

In further accordance with the invention means is provided whereby the sleeve 30 and the shell 20 are demountably but securely held in fixed interrelation under axial pressure of a high order, with the sleeve under substantial axial compression and the shell correspondingly under axial tension. This is accomplished through means whereby the sleeve 30 is secured at both ends by a metal-to-metal contact which is independent of any packing such as the compressible element 40.

For this purpose I provide an annular end wall member 50 formed as and constituting a regulating gland for the packing element and independently of the latter serving the function of providing metal-to-metal endwise thrusting connection between the shell 20 and the sleeve 30 at the inner end thereof. This gland and adjustable connector has a central aperture as at 5! for passage of the piston rod. It is externally threaded for cooperative reception in the internal threading 24 at the inner or mouth end of the shell 20, whereby it may be entered into compressive engagement with the packing element 40. Carried by the gland 50 is a plurality of threaded elements designated generally at 54 paralleling the axis of the liner assembly and in approximate line with the adjacent end face of the sleeve 30. These screw elements 54 of which a circular series of six are 'shown in the drawing are equally distributed in the end wall of the gland 58 around the central aperture 5! thereof. Each comprises a screw proper 55 including a readily externally accessible wrenchreceiving head. At the inner end of each screw 55 is a shoe 57 disposed at the inner face of the gland 50 as in a counterbored recess 56 in line with the threaded screw apertures. These shoes 51 are carried at the inner ends of the pins 58 extending freely through central longitudinal bores in the respective screws 55 and formed at the outer ends withretaining heads 59. The shoes 51 and the gland screws 55 accordingly are in. mutual swivelling relation. Thus in being tightened the screws turn against the shoes while the latter make firm abuttive metal-to-metal engagement with the adjacent end face of the sleeve 30. The shoes 51 further facilitate proper abuttive relation for the screws 55 with different sizes of sleeves 30.

Referring to Figs. 2 and 4 it will be apparent that the sleeve 30, the metal bushing 35 and the packing and junk ring element 40 form a subassembly which may be installed as a single'unit by relative telescoping with a shell 29.

of the shell, at the left in Figs. 1 and 2. Relative telescoping movement brings the shell and sleeve into approximate transverse line at the outer ends when the steel bushing 35 takes up against the in-facing shoulder 23 on the shell. The end wall and gland member 50, with the screws 54 backed out, is then turned into the Suchsleeve unit is entered at the inner or mouth 'end' 4 threaded inner end of the shell 20 and is made up sufiiciently to compress the packing. Thereupon the screw and shoe elements 54-59 are tightened securely against the sleeve 30. The entire assembly operation requires but a few minutes.

From the description in connection with the drawings it will be understood that the sleeve 30 and the shell 20 are relatively secured at both ends by a metal-to-metal contact, at one end by the steel bushing 35 and at the opposite end through the gland 5i] and swivel-related shoes 51 and screws 55. This metal-to-metal retainment of the sleeve, which is independent of the packing, and the associated means for exerting high axial pressure on the sleeve through the series of screws insures a tight sleeve throughout the entire service life.

The hardened wear-resistant sleeve 30 may be quickly renewed on the job, for example at the drilling rig, and at but a fraction of the usual cost for an entire new liner.

maintenance. By keeping the sleeve in good order the life of the piston is extended. Further, the investment for a variety of bore sizes is reduced, the cost of sleeves being substantially less than for liners. With one complete set of the liner assembly parts at hand for a given size of bore the operator needs to acquire only the sleeves, bushings and packings for any other bore size. Again, the same sleeves and associated internal parts are interchangeable over a wide range of pumps thereby further reducing warehousing and inventory problems for the oil well driller.

My invention is not limited to the particular embodiment thereof illustrated and described herein, and I set forth its scope in my following claims.

I claim:

1. A pump cylinder liner assembly comprising a cylindrical shell having near the outer end an internal in-facing annular shoulder and being internally threaded at the inner end, a hardened metal sleeve receivable coaxially in the shell and having adjacent the outer end an external out-facing annular shoulder near the inner end an opposite in-facing annular shoulder, a metal bushing interposable between the sleeve and shell in abuttive relation between the outfacing sleeve shoulder and the in-facing shell shoulder, an annular packing and spacing element receivable between the sleeve and shell in abuttive relation to the in-facing sleeve shoulder, an annular gland externally threaded to en: ter the threaded inner end of the shell and into of the packing and with the sleeve under com pression and the shell under tension axially.

2. A pump cylinder liner assembly accordin to claim 1 wherein a sleeve-engaging metal shoe is carried at the inner end of each of the screw elements in swivelling relation thereto.

3. In a pump having a cylinder for a reciproeating piston, a cylinder liner shell removably.

fixed in the cylinder and having open inner and outer ends, a replaceable hardened metal sleeve substantially commensurate with the shell lonv gitudinally and coaxially' positionable therein Thus under the. invention material savings are effected in pump by telescoping entry at the inner end thereof, axially interengageable abuttive stop means for the sleeve and shell remote from the inner end of the latter, an internal threaded formation on the inner end of the shell, an annular end wall member externally formed for threading into said shell inner end, and a plurality of longitudinal screw elements carried by and extending through said member in general line with the shell and adapted for turning up against the adjacent inner end of the latter to impose axial compression thereon and axial tension on the liner in mutual rigidly retained relation.

4. In a pump according to claim 3 the construction and arrangement wherein the abuttive stop means includes a metal bushing on the sleeve and within the shell, and the sleeve and the shell have out-facing and in-facing annular shoulders respectively for opposite abutment with the bushing.

5. In a pump according to claim 4 the construction and arrangement wherein the metal bushing has an external out-facing shoulder engageable with the in-facing shoulder of the shell.

6. In a pump according to claim 4 the construction and arrangement wherein the end Wall member is formed as a gland, the sleeve has an in-facing annular shoulder near the inner end, an annular packing element surrounds the sleeve between the inner end and said shoulder, and the end wall gland member is adapted to compress the packing element independently of the compression-tension relation imposed on the sleeve and shell.

7. For a cylinder liner, an externally threaded annular metallic gland element centrally apertured for passage of a piston rod, a plurality of screw elements paralleling the gland axis and symmetrically disposed around the central aperture, each screw element having an axial bore, and a metal shoe at the inner end of each screw element and having a carrying pin freely rotatively received and retained in the bore of the corresponding screw element.

8. A sleeve assembly for unitary insertion in a pump cylinder liner shell, comprising a metal sleeve of uniform inner diameter and of extreme hardness throughout the entire inner surface, said sleeve having a main intermediate portion of generally uniform outer diameter and bein externally reduced at each end beyond the intermediate portion to provide annular shoulders oppositely facing the adjacent sleeve ends, a metal bushing fitted on one end of the sleeve in abutment with the shoulder thereat and itself having an external out-facing annular shoulder, and an annular packing and confining junk ring element fitted on and abutting the shoulder at the other end of the sleeve and adapted to receive compression independently of the pressure-tension status of the shell and sleeve.

9. A pump cylinder liner comprising an outer cylindrical shell, an internal infacing abutment at one end of the shell, a hardened sleeve coaxially disposed in the shell, internal threading at the other end of the shell, a gland having external threading engaged with said internal threading of the shell and carrying externally accessible screw members extending lengthwise through the gland and engaging the adjacent end of the sleeve for exerting endwise pressure on the sleeve and endwise tension on the shell.

ARTHUR L. LEMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 968,029 Cross Aug. 23, 1910 1,592,266 Hamer July 13, 1926 1,768,799 Stanley July 1, 1930 1,792,941 Stevenson Feb. 17, 1931 1,804,542 Gardner May 19, 1931 2,259,432 Failing et a1. Oct. 14, 1941

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