US2367185A - Piston - Google Patents

Description

Jain. 16, 1945. A. P. CARY 2,367,185

PISTON Filed News; 1941 2 Sheets-Sheet 1 4 Anna/2 P CAQY INVENTO ArroBA/EV A. P. CARY Jan. 16, 1945.

PISTON Filed Nov. 6, 1941 2 Sheets-Sheet 2 Aernue P 643) mveiu'ro BY W2.

Patented Jan. 16, 1945 I V UNITED: S AT S PATENT OFFICE 1,, Is'roN f I Arthur Cary, Gainesville, Tex, Application November 6, 1941,;- Serial No. 418,008 "j 'j 26m ns. renew-+4); f

p This invention re'latesi..to' improvements in pumps of the type commonly referred to as mud pumps employed in connection with rotarydrill-- ing of'wells, and it has particular reference to improvements calculated to prevent or minimize excessive wear by abrasive materials inis'uspension in the fluid pumpedand its principal object resides intheprovision of wiping elements for the piston'and pistonrod' of the pump designed to cooperate with the piston and the piston'rod, as well as the pump liner; 'to'preven-t the accumulation of abrasive substances on the wearing "sur faces in the path of the piston and piston rods as these elements are operated in the-fluid. M

Another object of the invention resides in'the provision of an irrigating system; whereby "a stream of fluid is injected into the'pumpfto aid in removing the abrasive substances clinging to the Working surfaces and thusprevent cuttingo f the surfaces and wear resulting inleakage.

Still another object of the invention-resides in the provision of an assembly of wiping-elements adapted to operate in the path of the piston't'o remove the attendant accumulation of sand and grit in front and behind the piston to; prevent excessive wear on this member-, ras' wellfasthe lining within the cylinder, affording substantial1y a squeeg'ee action on thesurfaces of the liner, thus prolonging the life of the assemblyresulting in a great saving'of expenseand time.

Yet another object ofthe invention is manifest in the provision of a structure adapted to afiordan irrigated housing or sleeve suitably proportioned .to the longitudinal movement of the piston rod toinsure a clean surface there around throughout the length of the pistonfrod passing through the stuffing box opposite the piston: v

; Broadly, the invention seeks to comprehend the provisioncof an assembly of cleaning apparatus adaptedto keep the engaging. surfaces of the piston :and piston rod clear of'all abrasive substances. in-suspension in the fluid pumped, thus prolonging the lifejof the several parts of the pump beyond that common to the conventional typegof equipmentyet capable of being provided at a nominal "cost" for installation in standard makes and designs of pumps; E

-While the foregoing .objects are paramount,

other and lesser,v objects will become manifest as.

the description-proceeds taken in connection with the appended drawings wherein:

Figure 1 is'a fragmentary longitudinal crosssectional illustration of a pump. showing a tensioned wipinggland surrounding the piston rod An object of the'invention is also that'of pr'o- "viding for the injection of water,- or a suitable lubricant, into contact with the operating surfaces of the piston rod and the pistonyas wall-as the cylinder liner, such injections occurring upon the movement ofthe piston in the cylinder.

A further object of my invention is to provide a means of cleaning the engaging surfaces ofthe rods, pistons and liners, without the necessity of providing an auxiliary pump to supply water or other cleaning fluid under highcpressure, and without the injection of water in such excessive volume as to unduly dilute the drilling fluid with resultant injurious loweringof its viscosity: for

the viscosity of-a drilling fluid must be carefully controlled to obtain maximum efilciencyindrillins operations.

and illustrating. the'wiping rings arranged on each side ofthe piston. 1 I

Figure12 is a, fragmentary cross-sectional illustration, of a pump in 'Whih"l3h8 invention .is shown slightly modified, with respect to the tensionedwiping assemblyv for the piston rod, and illustrating the 'p'isto'nand wiping rings in elevation. f'

vFigure 3. illustrates theinvention installed in a, pump and shows a modified formof stufiing box .having an integral sleeve o'rl hous'ing in which the piston'rod is enclosed, the'said housing being irrigated to clean the piston rod in its movement therethrough.- I 1 Figure-'4 is a side 'elevational illustration of one of the wiping rings employed in combination with the piston for cleaning tne liner within the cylinden, 1: V Figure 5 is anende'levational view of the wiping gland shown-installed in Figures 1 and 2, and

Figure 6 illustrates, "inlong' tuoinal cross-section, the wiping gland snown in F gure 5, and is a view taken on 'li'nesLiL-fi of Figure 5;

Drilling fiuidi'employe'd in the drilling operations of oil andwater'wells, of necessity contains much abrasive materials which are drawn through thepumpfor such fluids andfiuch abrasive materials I quickly" wear vthe surfaces of the working parts of the pump unless. theselsurf'ace's are cleaned constantly. -'Ihe most practical means of cleaning these surfaces seemsto be that of flushing the piston rod and liner withwater, orother suitable fluidyat each operation of the moving part' and, at "thesame time, provide 'w'ip ing-means for the'movin'g" part to remove the abrasive substances from" the contacting surfaces before the packing on eith'erthe pistonor in the stuifing box of the rod comes into contact with the moving surfaces. An object of the invention, therefore, is that of providing for these elements.

My experience with pumps handling severely abrasive fluids has demonstrated that it is not necessary to inject water under pressure from an auxiliary pump to the various engaging surfaces, since my construction either protects the rod entirely from contact with the abrasive mud, or wipes the rod -andlinerclean of adhering abrasives, thesame thenbeing flushed away fromthe various Wiping elements by the action of water drawn into the pump by its own suction from an outside source at atmospheric pressure and the volume of water required for such sealing and/or flushing action is negligibly small compared with the volume of drilling fluid being handled by the pump. The volume of flushing-fluid employed with my structure can be controlled by the tinclusion in the supply line of a conventional valve.

The inventionis designedto beainstalled in a conventional pump which has been fragmentarily illustrated incross-section. The-pump cylinder I is provided with a liner :2 within w-hichthe pump piston.3 operates. The piston =3 will-be presently described in detail. The: liner 2v terminatesat a shoulder 4 forme'd within one end-of the cylinder I, as illustratedain Flgures 1,.2-.and 3, against'which a-packing ring 5 is placed and which is designed to prevent leakage aroundthe outer Wall of the liner-2. Thecylinder I 'is provided with suitable: inlets oroutlets-Ii.

The pump operating -mechanism is housed within a casting I, fragmentarily illustrated, adapted to be arranged adjacent the cylinder I and secured thereto by-bolts.8,. or=the like,- which also serve to secure the stufiing boxassemblyll for the piston rod.ID operating therein.

The engaging ends of the-cylinder l and=the member 1 are each provided with=openings :II

registering to afford a circular passage receiving an integral cylindrical extension I2 iofrthe stuffing box assembly "9 which extend into-:the.cylinder I in. the manner illustrated: in Figures11, 2,.and =3. The stufiing box assembly 9 is shown in modified form .in the several :illustrations 1 but generally consists of .a. castingrformed .Witha oircularjflange I3 through which thebolts -.8(extend.for. securing the assembly .to .themembers-Jand "I. lThe ,cylindrical extension I2rofrthe assemblyililisrinte ra with the flange I3. On the opposite sideiofgthe fi nce .7! 3 "there; is 1 provided int g a rho l 4 proj c n from the flan e l rans harme em nterne d amete sumeien te-accnmmedataal ring I5 adapted to repose against a should e 41 ande .p e ner ns 1 Sheilasuitebl pack ng m t ia ec red .i posi io b ee -f ll we J retam b b t l h heed inte h bq 4- The piston; rod I0 isadapted to slidethrough the packing ring I6 and the junk rin g L5 adjacent thereto andfunction ,to prevent leakage of fluids past the stuifing box assembly and into the member I. .Forwardly of the iunk ring I5 a wiping gland I9 isarranged within the cylindrical extension I2 of the stufiing box assembly and is retained in position by a tension spring ZIIbearing against the end ofthe wipingglandIB at one end, and against the'junk ring I5 at'its-opposite end. Thus the wiping gland 19 is constantly urged against-theend of the member opposite the packing ring -I6 secured bythe follower Isl. A junk ring'2I .isralso provided inx-therendzofithe member I2 against whichvtherwipingigland'ils engages. The end. orthe .memberstlzis upsets-or flanged inwardly rand ..-red11e :to ran :onenins as the-rod passes through this member. The "Wiping'memberIS is preferably composed of a flexible material such as rubber, neoprene, or the fzli As the rod I0 is operated through the stuffing box assembly the chamber 23 formed within the member l'lof the stufiing box assembly 9 is intermittently irrigated or flushed with fresh water, or other isuitable lubricant, supplied througha line 24 extending from a source at atmospheric pressure into a passage 25 formed in therendpfthe member fl adjoining the pump cylinder; I, as illustrated. in. Fi ures land 2,:Whi0h passage communicates {with a circular groove .126 formed ;within 'thechamberg23 in the member. I'Z. Fluid is: drawn intosthemember I 2 and into contact .with'the piston: rod 2 I0 upon each movement of 1 the piston as illustrated, -;away from the stuffing; box assemblyi'9 since, the pistons-3 creates wa -.suction=.thereb.ehind which exerts, a puilgon the flu d nthe dine 2 an b treas .o 1a .ch valve 21 the line 24, the irrigating fluid is permitted to pass "1 through i the line only when :sllQtiQnisa-pplied by ;,t l- 1 e piston 53in the manner just described.

{Ihe yflushingraction ;of the'rwater dIaWI'l into t e tehamber 12: :e d into en act with t e od 10.- s rveszt r m vefrom 1thev.sur a er of the red any :adherin a ra iv substan s wh n applie in cooperation-withtheccntae in i ibs 5 2 of the p n glan I mrevieus sdeSGribed. :F llre shows :a modifie t rm of stufi n v e ass mb y 1 wher i stheaw i a slen I end thetensioned device 12; are remitted .;-a d the m d introduced f flush n ith r odzras es rt r ug ine :2 end directlyinto the stufling box casting communicat n wit za i u a .wgroovev 2 t .i h bo e .2 -ath o s which th re 591 s ada t d to f nctio The cond t n: under Whichthi Jm d fied e mmav b use l bedis u e r e ntl e stutfins i-b x assembly .9 I ulus rate in i ure -3 comprises;a casting having a flange 'I3 fe seem n :thismemh to the-membe l a lend e zinte nertie 0 extend n i t th passa e. torm d'b theep i l l l the :memher I lead 1, eni nte ra rex ended nertie n hich gnroieets int the ae inde -,f.o. m. e slee e v .heusin thepisten :red '1 The sleeve 3|, coupled with the portion of the stufiing b x assemb y pr des .e an longate bo .nmmt et ns eapis on rod-5 l ra e i thet pcrtic of its len th e posed n -:th e pi t s e f t e packin ins 1- s cure b h ow r Al around the red It]. In-other ords, :the {complete operative-.surfacepf-the-rod IO-isprptected by the extension 3 I whose; inner bore 29; provides an a ular ch be za oundith vre t roug whieh tb i ri a ng flu d ent ring through th line 2 sflowsto was ou r headher nei rasive mat r al en.:t ,.su ae ;0 the d ansom-eac rieh werdl lm v ment illus rated .e th r H .lensitudin l wit n t p i er. Th c eck xva re -2 :n etent :th massage of :fluicis e ia en is ur ed (as .,y ;;o r;; n the direetionzcr the stufifing box assembly 9. 1

It'will be noted that the shoulder a for the liner 2 is shown in Figures 1, 2 and'3 progressively farther removed from the left end 56 .of the cylinder casting I to correspond with the construction employed in various pumps. Since the location of this shoulder'determines the point-of maximum leftwardly travel of the piston in any additionalextension 55. i

In Figure '2 is shown a type of pump in which such an additional extension; 55. is possible. While in Figure 3 a type of pump is shown in which the extension or sleeve 3| can be made so long that the wipinggland is not necessary, since the distance A is greater than the stroke of the pump. That is, no part of the rod which passes through the packing I6 is ever in contact with abrasive-laden mud, even when the rod is at its point of maximum rightwardly travel. In Figure 2 such is not the case, but the short extension 55 reduces the amount of abrasive which the rod I carries to the wiping gland I9 and thus prolongs the useful life of the latter.

The piston 3, being substantially conventional in construction, comprises a body 32 which is cylindrical in form and which is provided with an integral flange 33 intermediate its ends, as illustrated in Figure 1.. Rings 34 of a fibrous material are arranged over th body 32 and engage the opposite faces of the flange 33. Composition rings 35 and 35', composed of rubber, neoprene,

within the body 32, asillustrated in Figure 1,

- obviating the necessityof registering the outlet passages 53 of the passages 43 and 44 with the ports 59and 5I. The passages 43 and 44 are preferably bored through the shaft from one end thereof and plugged to each of the passages 53, respectively, as shown in Figure 1.

Upon each operation of the piston assembly the irrigating. fluid passing through the line 49 from the source is injected into the cylinder I and in the path of the piston and the wiping disks 39 and 39' by reason of the suction created by the piston in its movement. Thus, as the piston travels away from the stufling box assembly a suction is created therebehind drawing the fluid through the passage 43 into the liner 2 and in the path of the wiping disk 39 on the inner side of the piston assembly, While the fluid is subsequently introduced to the opposite or outer side of the piston assembly and in the path of the wiping disk 39' through the passage 44,

the check valves 41 functioning to open only when a suction is created in either of the lines or the like, their outer faces being concave or The body 32 is formed at each end with an.

annular shoulder b against which circular disks 38 engage, the latter being engaged by wiping disksor rings 39 and 39', illustrated in Figure" 4, which are secured by similar plates 40 by retaining rings 4 I surrounding the extreme ends of the body 32,'as illustrated in Figure l.' The piston assembly, including the body 32, rings 34, 35 and 35', as well as the Wiping disks 39 and 39, are secured to the tapered end of the rod ID by ock nuts 42 threaded upon the rod I9, in the manner illustrated in Figures 1, 2 and 3.

The irrigating fluid is also introduced through passages 43 and 44 extending longitudinally through the rod IIJ, as illustrated in Figure 1, each of which connect with separate inlet conduits 45 and 46, respectively, and which are provided with check valves 41, similar to the check valve 21 in the line 24, and merge through a T- connection 48 with a flexible line 49 connected to a source. The passage 43 in the shaft I9 communicates exteriorly of the body 32 through a port 59 between the inner wiping disk 39 and the inner composition piston ring 35 to inject the irrigating fluid into the cylinder I in the 45 or 46, alternating in accordance with the travel of the piston assembly 3.

The peripheral faces of the wiping disks 39 and 39 are provided with diagonal ribs 54, illustrated in Figures 2, 3 andl, adapted to contact the inner surface of the liner 2, yet having their ends overlapping so that there is no direct passage in a straight line therebetween but allowing for the passage 'of the irrigating fluid past the ribs 54 and into contact with the surface of the liner 2. This arrangement provides for the thorough cleaning of the inner surface of the liner 2, cooperating with the fluid introduced through the outlet ports 50 and 5| between the wiping disks 39 and 39' and the piston assembly 3 removing allabrasive substances from such surface.

The conservation of space is an important object of the invention and particular attention is directed to the compact design of the stuffing box assembly 9, as especially illustrated in Figures 1 and 2. It will be noted that the major portion of the assembly extends into the cylin- {irrigated surface within the chamber 23 of the member I2. In Figure 2 greater protection is provided for the rod ID by an integra1 extension 55 forming a part of the portion I2 of the stuffing box assembly 9 surrounding the rod I0. An annular space around the rod I0 within the member 55 provides for the passage of the irrigating fluid therethrough and around the rod I9 to clean its surface. lar to that illustrated in Figure 3.

It isobvious, also, that the members I and I of the pump assembly may be spaced apart when desirable by placing suitable spacing members (not shown) therebetween and lengthening the retaining bolts 8. The stufiing box assembly may be accordingly increased in length, as well as the rod I9, if desirable. Under certain conditions such an arrangement might expedite the oper ation of the assembly.

As a homely illustration of the effectiveness of the cleaning mechanism employed in certain v forms of my invention, as well as of the small volume of water required for such cleaning action, the wiping gland I9 and wiping disks This arrangement is simi- 39-739 p-may the Qcompared ,with :a :conventional windshield :wiper, :which 415 effective even :in "Va ilight "drizzle. While golder rmetho'ds of rcleaning :both piston rod.1 and;,1iner by the injection rof water under .high pressure .ifrom .an 1 auxiliary benefit gof :wiping during gthegprocess. tvolume :of water would be :required under @high pump may. be comp ared; with: attempting to :clean a Windshield with water ifrom ahosepwithout A large pressure-with indifierent :results.

2. It is not :intended that the =V invention the :re-

:stricted to; the specific construction herein shown carrying abrasiveshaving a-pump cylinderand w, :cylinder glinermnd. saianiston :a-nd xpiston L ITOd, -fiexib1ewwiping vdisksv for1zthe said .t-liner aadapte'd to.;cooperatezwithithe;said;-piston.1each of" the :said .ihavingratseries of diagonal :ribs disposed around :their; peripheral: faces-defining fluid passages t-therebetween z and engaging the 1 operative surfaces of the said liner in the paths .ofthe said piston in zeithertdirection of its travel.

2. slnw. .zpumping:mechanismz-for;:drillingifluids in: an oil ;well yincluding-.zarcylinder having a; liner and-a, pistonsandapiston 'rod operative'lyrarranged therein, :flexible :wiping disks ,2 for ithe said liner larranged 130115621311 aside of1..the:said :piston 'on' the saidarodgthe said:disksi-formedwvithta peripheral arrangement of diagonal :ribs defining grooves .therebetween forrthetpassageof fiui'dand engagtingstheiinnerzsurfaces ofthe isaid liner .in either direction; of travel of .thegsaid' p ARTH'UR *P. CARY.

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