US2277501A - Slush pump piston - Google Patents

Description

March24, 1942. P; F MURRAY 2,277,501

sLUsH PUM Pis'ron A Filed Dec. 28, 1940 Patented Mar. 244, 1942 l sLUsH PUMrrls'roN Pcxton F. Murray, Montebello, Calif., assignor of one-half to A. H. Gandy, Bellflower, Calif.

Application December 28 1940, Serial No. 372,113

11 Claims.

My invention .relates generally to pistons and 'more 'particularly to the pistons of the slush pumps that are utilized `for effecting a circulation of fluid through deep wells for the purpose of bringing the cuttings from the drill to the sury face, and the principal objects of my invention are, to generally improve upon and simplify the construction of the slush pump pistons now-in general use and to provide a piston having a narrow double lip ring-type piston sleeve of rubber, or composition of which rubber is one of the ingradients, that is molded into specially designed grooves in a core, so as to very securely anchor the sleeve on said core and preventing the bulging of the rubber or composition of the sleeve in the concave area between its lips.

Further objects of my invention are, to pro vide a slush pump piston that is capable of being readilyv appliedA to or removed from the piston rod, the construction being such as to eliminate removal of the .rod from the liner in order to replace the sleeve, further, to provide for a perfect fluid pressure tight joint or seal against Washing between the sleeve and spool and further, to provide a piston having 'a sleeve carrying spool that will receive various sizes of sleeves when reducing the pump liners, thereby effecting a material saving of time, labor and consequent expense when repairing the pump in which the piston is used.

A further object of my invention is, to provide a slush pump piston that is constructed without exposed rims in the central portion of the periphthe rubber in the sleeve when pressure forces produce a bulging of the sleeve at the joints or seams between the rim and sleeve.

In former years slush pumps operated'at a pressure not greater than three hundred fifty pounds due to the fact that the well holes were shallow and the operators reliedon the bit to cut 'the formation and carry away the cuttings up and around the drill pipe.

Under deeper drilling conditions, the slush pumps were increased in size and volume and higher pressures were required. Under the pres- Under present conditions of drilling deep wells, tests show that the circulation fluid travels upwards of one hundred miles per hour when it reaches the bottom of a ten thousand foot hole and thus the slush. pumps, their pistons, rods, and liners, must be constructed and have the capacity for maintaining the fluid in constant acs tion during drilling operations.

Sharp sands have been a menace in causing rapid wear upon the pistons,` rods, and liners, but] the use of new types of shalers and desanders is eliminating this particular problem.

The high 4pressures plus the heat caused by constant friction of a rubber piston against a liner during long strokes, develops piston failures. When the lips ofy the rubber sleeve on the piston are cut, distorted, or become worn, the washing vof the fluid by the piston not only washes the yery of the piston sleeve, which exposed rims tend to score the pump liners or to cause shearing of i upwardly to bring the cuttings, to the surface. 5:

piston body but also destroys the expensive liner and the piston rod, and the replacement of these parts involves considerable time, labor, and consequent expense.

Adangerous condition is also developed in the event that the pump becomes inoperative While the pipe is on the bottom of the hole, as loss of pressure may -result in a cave-in of the hole, thereby freezing the drill pipe, or a gas pocket may cause a blowout resulting in the loss of the hole. Therefore, it will be understood that good pumps are very essential in the drilling of deep Wells.

With the foregoing and other objects in View, my invention consists in certain novel features of construction and arrangementgof parts that will be hereinafter more fully described and claimed and illustrated in the accompanying drawing in which:

Fig. 1 is a sectional Aview of a pump liner and showing my improved'piston positioned therein, with parts of said piston in section.

. Fig. 2 is a cross section taken on the line 2 2 of Fig. l.

Fig. 3 is an enlarged detail section taken through the outer portion of the metal ring that carries the rubber ring or body of the piston.

Referring by numerals to the accompanying drawing, I0 designates a conventional pump piston rod provided near its end with a tapered portionl II that receives the sleeve of the piston and the terminal portion of the rod beyond the tapered portion I`I is threaded as designated by I2.

A sleeve or quill I3 is bored and reamed so as to receive with a precision t the tapered portion I I of the piston rod. 'In some instances, that portion of the rod that receives the sleeve or quill may have the same diameter throughout its length.

Formed integral with the inner end portion of the sleeve I3 is a circumferential flange I4 pro- .vided on one of its side faces with a rib I5. This ange provides a stop for limiting the movement of the ring of the piston inwardly upon said sleeve and the rib I5 is adapted to be embedded in the rubber body of the piston and which is carried by the ring to produce a sealing effect in providing a. fluid pressure tight joint.

The outer end portion of the sleeve I3 is externally threaded as designated by I6 for the reception of a nut I1, which latter retains the ring of the piston and the rubber body carried thereby securely in position upon the sleeve I3. When tightened upon the threaded portion I6 of the sleeve |3, the outer end of nut I1 projects a short distance beyond the adjacent end of the sleeve and said nut is locked to the sleeve by means of a lock nut I8 that is screw seated on the threaded end portion I2 of rod I0.

The sleeve I3 when properly seated on the portion I5 of the piston rod, in effect becomes a permanent part of the rod and it is not necessary to remove said sleeve when changing the size of the liner in the pump and which change obviously necessitates a change in the size of the piston.

Formed integral with the inner end portion of the lock nut I1 is a circumferential flange I9 simi-v lar to flange |4 on the sleeve I3 and formed on the inner face of said flange I9 is a rib 20 having practically the same construction and function as rib I5.

Removably positioned on the sleeve I3 between the iiange I4 and the inner end of lock nut I1 is the body 2| of the piston, said body being preferably formed of steel or similar hard metal and having the form of a ring.

Formed in the side faces of the ring 2| adjacent and concentric with the opening therethrough -are grooves 22 which, when the parts of the piston are properly assembled, occupy positions directly opposite the ribs I5 and 2II on the flanges I4 and I9 respectively and said grooves receive ribs or flanges that are formed' on the inner portion of the rubber body of the piston.

Formed in the peripheral face of the ring 2| is a plurality of circumferential grooves 23 that receive rib-like portions of the rubber body of the piston when the same is molded or cast upon the ring. The formation of the grooves 23 in the core provides circumferential ribs 24 and also circumferential ribs 25 on the ends of said ring.

Formed in the ribs 24 and etxending inwardly toward each other'from the side faces thereof are concentric grooves 26 and similar grooves 21 are formed in the inner faces of the ribs 25 at the ends of the ring.

As a result of the construction just described, the outer portions of the ribs 24 are substantially T-shape in' cross section and the outer portions of the grooves 23 are substantially of inverted T-shape in cross section.

.The flexible or elastic body 28 that is molded on the ring 2| is composed of tough, wear resisting rubber or composition havngi rubber as one of its principal ingredients, and said body entirely covers' that portion of the ring outing or cutting action of fluid pressures while the piston is in operation.

Portions 23 of the body cf rubber completely fill the grooves 22 and side wall portions 30 completely cover the outer end portions of the ring 2| and a circumferential portion 3| completely covers the outer faces of the ribs 24. The outer face of the circumferential portion 3| is recessed to form a shallow, circumferential, concave groove 32, and as a result of this construction circumferential lips 33 that are substantially wedge-shape in cross section are formed at the edges of the end faces of the rubber vbody and the outer faces of which lips ride directly against the inner face of the liner L and provide fluid pressure tight joints between Athe rubber body and said liner.

When the rubber bodyhis molded onto the ring,

portions 34 o f said body completely fill the grooves. 23 and the lateral grooves 26 and 21,

thus providing lsubstantially dovetail joints o1.

connections between the outer portion of the rubber body and the ring and such construction eifectually prevents outward bulging of the intermediate portion of the rubber body when the piston is subjected to high pressures.

The width of the rubber body forming a part of my improved piston is considerably less 'than that of the pistons now in general use in slush pumps and the like, and as a result of this narrow construction there is a substantial decrease in the frictional resistance between the rubber and I the inner surface of the` liner.

The molding of the rubber body in one piece upon the ring provides an exceptionally strong and substantial structure that will withstand high pressures and the rubber body, together with its ring, is held firmly in position upon the sleeve no exposed seams or joints exposed to the wash- I3 by the flanges I4 and I9 and the sleeve is firmly retained on the piston rod bythe nut I8.

After the piston has been installed on the rod and it becomes necessary to replace the rubber body of the piston due to wear or disintegration, it is only necessary to remove the nuts I8 and I1 which permits the ring and rubber body to be readily removed from the s1eeve, which latter retains its position upon the piston rod.

A new ring and the rubber body carried thereby is now positioned upon the sleeve and rigidly anchored thereto by applying the lock nut I1 to the threaded end of the sleeve I3 and applying nut I8 to the threaded end of the piston rod. These operations may be accomplished without removing the rod from the pump.

As the pump liners are reduced in diameter,

the diameters of the rubber bodies on the sleeves are correspondingly reduced, -but the diameter of the sleeve and the sizes of the lock and rod nuts remain the same inasmuch as they are permanent elements of the piston.

Conventional slush pump pistons range in sizes from five inches to nine and one-quarter inches in diameter, but my improved piston may be made in smaller sizes for use in various small size pumps used`in the industrial field.

Thus it will be seen that I have provided a slush pump piston that is relatively simple in construction, inexpensive of manufacture and very eective in performing the functions for which it is intended.

It will be understood that minor changes in the size, form and construction of the various parts of my improved slush pump piston, may

be made and substituted for those herein shown y of my invention, the scope of which is set forth in the appended claims.

I claim as my invention:

1. In a piston for pumps and the like, a piston rod, a sleeve removably positioned thereupon, a ring removably positioned upon said sleeve,- a onepiece body of flexible material enclosing the outer portion of said sleeve and interlocking flanges on the external periphery of the ring and the internal periphery of said body of flexible material.

2. A piston as set forth in claim 1 and with means removably mounted upon said sleeve for retaining said ring and flexible covering member upon said sleeve.

3. A piston as set forth in claim 1, with means removably mounted upon said sleeve for retaining said ring and flexible covering member upon said sleeve and means removably mounted on the piston rod for retaining said sleeve andthe parts carried thereby upon said piston rod.

4. In a piston for pumps and the like, a piston rod, a sleeve removably mounted on said piston rod, a ring removably mounted on said sleeve, said ring being provided in its peripheral portion with a circumferential undercut groove and in its end faces with grooves, a one-piece body of flexible material entirely enclosingA the outer portion of said ring, with portions of said flexible member occupying the undercut grooves in said ring and other portions of said flexible member occupying the grooves in the end faces of said ring.

5. A piston as set forth in claim 4 and the periphery of said flexible body being provided i with a shallow, circumferential, concave face.

.flexible material enclosing the outer portion of saidiring, with integral portions of said body anchored in said undercut grooves.

7. A piston as set forth in claim 6 and the periphery of which flexible body is provided with a circumferential, concave face.

8. A piston as set forth in claim 6,-with concentric grooves formed in the end faces of said ring, with portions of said body of flexible material occupying said grooves and flanges on the partsv of said two-piece sleeve, which flanges bear against those portions of the body of flexible material that are seated in said concentric grooves.

9. The combination with a piston rod, of a twopiece sleeve removably positioned on said rod and a piston body removably positioned on said sleeve and comprising a, one-piece ring and one-piece body of flexible material enclosing and anchored upon the outer portion of said ring.

10. The combination with a piston rod, of a sleeve removably positioned thereon, a ring removably positioned on said sleeve, 'a one-piece body of flexible material enclosing andanchored upon the outer portion of said ring, a nut screw seated on said sleeve for securing said ring and body of flexible material on said sleeve and means removably mounted Aon said piston rod for secur- 'ing said sleeve and nut on said piston rod.

11. In a piston for pumps and the like, a pistonv rod, a two-part sleeve detachably mounted on said piston rod, the parts of said sleeve being adiustably connected to each other, a one-piece ring positioned on said sleeve between the parts thereof, said ring being provided in its periphery and its end faces with grooves, a one-piece body

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