US2923055A

US2923055A - Apparatus for changing pump liners

Info

Publication number: US2923055A
Application number: US504222A
Authority: US
Inventors: Jr William R Bradley
Original assignee: Jersey Production Research Co
Current assignee: Jersey Production Research Co
Priority date: 1955-04-27
Filing date: 1955-04-27
Publication date: 1960-02-02
Anticipated expiration: 1977-02-02

Description

Feb. 2, 1960 w. R. BRADLEY, JR

APPARATUS FOR cmmcmc PUMP LINERS Filed April 27, 1955 Aug William R. Bradley, J0:

Inventor Attorney APPARATUS FOR CHANGING PUMP L William R. Bradley, Jr., Tulsa, Okla, assignor, by mesne assignments, to Jersey Production Research Company.

Application April 27, 1955, Serial No.-50.4,222

' 3 Claims. (Cl. 29-283) The present invention relates to means for removing or installing the liners that are employed in reciprocating pumps. It particularly relates to an apparatus for' rapidly and conveniently changing the liners that are employed in oil field slush pumps. The invention especially concerns an apparatus for changing the liners in slush pumps without requiring the removal of the piston rods from the pumps. a i V Reciprocating pumps are well knownin the art and have found particular application as slush pumps in well drilling operations. The reciprocating pumps that are employed for this particular purpose are generally double acting pumps and furthermore are usually of the duplex or triplex type. The pumps, as their name indicates, are used for supplying drilling mud to the drill bit at the bottom of a bore hole and for conveying the mud from this point back up to the earths surface. I

Inasmuch as the pressure that a slush pump must develop increases as a bore hole increases in depth, it follows that means must be provided for changing the pressure and delivery characteristics of the pump as a drilling operation progresses. Specifically, it has been the practice in the industry to periodically change the cylinder liners and the pistons in such pumps as the depth of a bore hole increased. Thus, it has been the practice to start any particular drilling operation with a slush pump that contains a relatively large diameter cylinder liner and piston and to exchange the liner and piston for smaller sizes at intervals during the drilling operation. This procedure is repeated until the hole has reached its maximum depth, and in this way a pump of a given horsepower and speed may be adapted to deliver fluid or other drilling mud at substantially any desired pressure within the operating limits of the pump.

To date, several procedures and forms of apparatus have been employed for changing the liners and pistons in reciprocating slush pumps. and apparatus require that the cylinder head of such a pump be removed as a first step in getting at the liner and the piston. Then the liner spacer if any is'removed, and following this the piston and the piston rod are removed. A suitable screw jack, hydraulic jack or other suitable means is 'then inserted into the pump and is used to remove the old liner and to jack a new or replacement liner into position. Following-this, the piston rod, the piston, the spacer and the cylinder head are replaced.

While the foregoing procedure is widely employed in the industry for replacing cylinder liners and while'the procedure affords means for attaining the desired objectives, it is characterized by a number of undesirable features. Specifically, it is always necessary to remove the piston rod from a pump in order to replace its liner;

- and it is generally further necessary to repair, adjust or even entirely replace the piston rod packing. Furthermore, the procedure is time consuming and therefore expensive.

The problem of changinga piston in a slush'pump has 2,923,055 Patented Feb. 2, 1960 ice been recently simplified by the advent of a quick change type of piston which enables the operator to change the piston without removing the piston rod. Since the rod, however, must still be removed in order to change the liner, little real advantage has been realized as a result of this type of piston insofar as removal or replacement of the liner is concerned.

There is one form of apparatus which has been developed that permits a worn cylinder liner to be removed without prior removal of the piston or the piston,

rod, but this tool is used only in those instances where it is not desired to reuse the liner. The tool relies for its action on a plurality of teeth or jaw-like members that gouge into the liner and permit the operator to draw the liner from the cylinder.

Thus, no procedure or apparatus has yet been developed to exchange the cylinder liner and piston in a reciprocating type pump without prior removal of the piston rod from the pump. Accordingly, it is a particular object of this invention to afford means for attaining this goal. More specifically, it is an object of the invention to provide an apparatus which enables the operator of a reciprocating piston-type pump to remove or replace a cylinder liner from such a pump without removing the piston rod.

A complete understanding and presentation of the invention is best understood by first briefly considering the structure and operation of reciprocating piston type pumps and particularly reciprocating pumps such as are employed as slush pumps in oil well drilling operations. Accordingly, attention is directed to attached Figure l which illustrates in partial cross-section a reciprocating pump of a type which is employed in drilling operations. Turning to the figure, there are illustrated pump body 5, cylinder liner 6, piston rod packing gland assembly 7,

1 piston rod 8, sliding crosshead 9, crank shaft 10, herring All of these procedures bone gear 11, gear 12, jack shaft 13 and flywheel 14. The

piston, cylinder head, and liner spacer are not illustrated,

,belt to a suitable driving wheel not shown. 'Movement of the belt on the flywheel 14 causes the jack shaft 13 to revolve and the jack shaft drives the gear 12. Gear 12 drives herringbone gear 11, and gear 11 in turn causes crank shaft 10.to revolve. Motion and power from the crank shaft are translated into reciprocating motion of the piston rod 8 by means of crank 15, connecting rod 16, crosshead 9 and crosshead slide members 17.

Piston rod 8 normally causes a piston (not shown) to move in a reciprocating manner from one end of cylinder'liner 6 to the other end of the liner. In so doing the piston causes liquid to flow in and out of the two

chambers

20 and 21. It is apparent from the figure that the pump illustrated therein is of a double acting type in that it simultaneously exerts a suction stroke in one of the aforesaid chambers and a discharge stroke in the other chamber. It will be appreciated that the

chambers

20 and 21 are in direct fluid communication through the

ports

22 and 23 to suitable sets of suction and discharge valves that are not shown.

As pointed out earlier in this description, it has until now been necessary to remove the cylinder head as well as the .piston rod from a reciprocating pump before it has been possible to remove or replace the cylinder liner'. As further pointed out earlier in this description/the present invention enables one to attain these objectives without removal of the piston rod. The particular apparatus that attains this objective and that constitutes the present invention is illustrated in Figures 1-3 inclusive where:

' Figure 1 illustrates the novel device directly within a pump in the position that it would occupy for removing a liner from a pump.

Figure 2 is a perspective view of the device which is illustrated in partial cross-section in Figure 1.

Figure 3 is an end view of the apparatus in Figure 2 as it would appear in looking toward the puller hook end of the apparatus.

The apparatus of the invention is perhaps best illustrated in Figure 2 where it may be seen that the apparatus includes at least two puller hook members 31, two toggle arms 32, two links 36 and a rod cap 34.

Each puller hook member is preferably slightly curved so as to conform conveniently to the cylindrical shape of the cylinder liners that are employed in any given reciprocating pump. Furthermore, each puller hook member is provided with an outwardly flanged portion 40 which is adapted to grip around one end of the cylinder liner.

The two puller hooks that are illustrated in the attached figures are continuously thrust laterally apart by means of spring loaded toggle arms 32. Each One of these toggle arms is pivotally mounted to the interior surface of one of the puller hooks, and the opposite end of each arm is slidably engaged with the other puller hook. In order to guide the free end of each toggle arm 32, arm guides 38 are provided on the interior surface of each puller hook. These arm. guides form a grooved passageway which enables the free end of each toggle arm 32 to move longitudinally with respect to the puller hooks. By means of this feature the puller hooks may be readily compressed together or extended from one another without binding.

It is particularly noteworthy that the toggle arms 32 are laterally spaced from one another (as is particularly illustrated in Figure 3) so that a piston rod such as piston rod 8 may freely move between these arms. It is further noteworthy that the pivoted end 37 of each toggle arm is provided with a spring or other resilient means such as leaf spring 42 shown in Figure 2 which is arranged to continuously urge the free end of the arm away from the puller hook to which the arm is attached and toward the opposite puller hook.

Each toggle arm is connected to rod cap. member 34 by means of link members 36. These links are pivotally or otherwise conveniently secured to each toggle arm.

and may be made adjustable in length so as to accommodate pumps that possess diiferent stroke lengths. Alternatively, the links 36 may be made conveniently replaceable so that links of different lengths may be used when so desired. In any event the links should be of suitable material and strength such that the forces that are required to operate the device are provided.

Rod cap 34 is provided with a central'passageway 33 pump is illustrated with its piston head, piston and cylwhich is of a diameter large enough to pass freely over the piston rod. Furthermore, the rod cap is preferably provided with adjustable pins 39 which enable the operator to center the cap within a cylinder liner. Again, the rod cap may be provided with means for mounting the ends of the links 36 in different vertical positions, since it is particularly preferred that these members be maintained substantially parallel to the longitudinal axis of the cylinder liner. As in the case of the toggle arms 32 and the puller hooks 31, it is desirable that the rod cap 34 and the other component parts of this device be made of a material and structure such that the device possesses suflieient strength for its aforedescribed use.

The invention is even better understood by reference to the manner in which it is employed in a pump installation. Accordingly, attention is particularly directed toward a consideration of Figure l where body 5 of a inder liner spacer removed. The apparatus of the invention is illustrated in this figure in the position that it would occupy in order to remove cylinder liner 6 from within the pump body 5. Thus, the flanged members 40 of the two puller hooks 31 are depicted as engaging one end of the liner 6. Toggle arms 32 are shown urging the puller hooks 31 outwardly against cylinder liner 6, and link members 36 connect the toggle arms with the rod cap 34.

The adjustable centering pins 39 have been adjusted to center rod cap 34 along the longitudinal axis of the liner 6, and nut 41 has been run up against the rod cap to make the entire assembly snug. In other words, nut 41 is run up against the surface of rod cap 34 until the flanges 40 firmly engage the end of cylinder liner 6. It is apparent, of course, that nut 41 has to ride against that side of the rod cap which enables the nut to move the cap in the direction required to force the liner from the. pump. It is further apparent that the piston rod, crankshaft etc. are preferably positioned at the extreme end position of the pumps stroke such that the entire stroke travel can be utilized to drive the liner from its position within the pump.

At this point power is applied to the pump, and piston rod 8 is caused to move longitudinally along the axis of the cylinder liner 6. It will be appreciated that the necessary power may be obtained by utilizing the same power source that is employed to run the pump during its regular operation. It is preferred, however, that the piston rod be actuated in this instance by hand for obvious safety reasons. Thus, one or more persons can suitably and satisfactorily cause piston rod 8 to move by applying power to the spokes of the flywheel 14. Alternatively, a suitable jack, crank or lever may be applied to the jack shaft 13 or to the crank shaft 10. In any event movement of piston rod 8 causes flange members 40 to bear against the end of cylinder liner 6 and to thrust the liner from its position within the body 5. It is particularly noteworthy that the liner, once driven from its position within the cylinder, cannot be dragged back within the cylinder on the return stroke of the pump, since the piston rod rides freely through the rod cap in this direction.

To insert a cylinder liner within the pump body 5, a reverse but substantially identical procedure is employed. In this case the device is arranged within the cylinder so that the flanges 40 bear against the opposite end of the cylinder liner 6, and the nut 41 is placed in a position relative to cap 34 such that is causes the flanges 40 to thrust the liner within the pump. It will be appreciated that it will generally be necessary to employ longer link members 36 for installing a cylinder liner than are necessary towithdraw a liner. As pointed out earlier the links may be made either adjustable in length, or they may be made replaceable with longer links for this purpose.

In examining the apparatus in the various figures, it will be observed that the use of the liner puller apparatus affords several unique advantages. First, it enables an operator to replace a cylinder liner with a minimum expenditure of labor and time. Second, it reduces markedly the wear that otherwise occurs to the threads on the piston rods. Third, it obviates damage to the crosshead threads and to the piston rod packing.

It will further be appreciated that a number of modifications and variations may be incorporated within the apparatus without; departing from the spirit or scope of the invention. For example, a variety of different flange members may be. employed to grip the ends of the cylinder liners. Again, a number of puller hooks other than the two illustrated may be employed if so desired. Likewise, a. variety of toggle arms or other extensor-type members may be employed to maintain the puller hooks ina spaced relation with respect to one another.

What is claimed is:

1. An apparatus for moving a cylinder liner within the cylinder of a reciprocating type piston pump following removal of the cylinder head and piston but not the piston rod, said apparatus comprising at-least one pair of hook members adapted to fit within said liner in a diametrically opposite relation, the hooked portion of each hook member extending outward from said hook member and adapted to engage one end of the liner, a separate toggle arm pivotally attached at one end to the inner side of each book member, the opposite end of each toggle arm extending toward the hooked portions of the hook members and terminating against a radially opposite hook member, guide means on the inner side of each said hook member and adapted to receive said opposite end of said toggle arm in a longitudinally sliding relationship with said hook member, a rod cap member adapted to fit within the cylinder liner and provided with a hole so as to enable the piston rod to move freely therethrough, a separate link member pivotally attached at one end to an intermediate point along the length of each toggle arm and at the other end to said rod cap member, and means attachable to the piston rod for bearing against the rod cap member in a manner to urge the hooked portions of said hook members against said end of said cylinder liner.

2. An apparatus as defined in claim 1 including pin members attached to said rod cap member and adapted to center said rod cap member within the cylinder liner.

3. An apparatus as defined in claim 1 including resilient means arranged to continuously urge said hook members radially away from the longitudinal axis of the cylinder liner.

References Cited in the file of this patent UNITED STATES PATENTS 435,594 Teetzel Sept. 2, 1890 683,411 Norden Sept. 24, 1901 963,603 Lunceford July 5, 1910 2,487,902 Stout Nov. 15, 1949 2,566,507 Walraven Sept. 4, 1951 2,613,983 Knudsen Oct. 14, 1952 2,688,183 Oberley et a1. Sept. 7, 1954 2,697,872 Armstrong Dec. 28, 1954 2,706,658 Jewell Apr. 19, 1955 2,715,261 Williams Aug. 16, 1955