US2631541A

US2631541A - Hydraulic pump

Info

Publication number: US2631541A
Application number: US90953A
Authority: US
Inventors: Oscar E Dempsey
Original assignee: Byron Jackson Co
Current assignee: Byron Jackson Co
Priority date: 1949-05-02
Filing date: 1949-05-02
Publication date: 1953-03-17
Anticipated expiration: 1970-03-17

Description

March 17,1953 o. E. DEMPsEY HYDRAULIC PUMP Filed May 2, 1949 3 Sheets-.Sheet 2 INVENTOR.

O E. DEMPS u HIL 1 w 1 d .o 4. w m w u a M a M. n* m w p m ll llwlWMNJnlH \\h l n llll IJ AT Top Ney Marchn o. E. Dr-:MPSEY HYDRAULIC PUMP s shetsfsneet s Filed May 2, 1949 IIS lOZ

INVENTOR.

y M D. o am M C,

IIS

Y E N E C T T A Patented Mar. 17, 1953 HYDRAULIC PUMP Oscar Dempsey, Tulsa, ykla.,V assignor, by mesne assignments, to Byron Jackson Co., Los Angeles, Calif., a corporation of Delaware Application May 2, 1949, -Serial No. 90,953

12 Claims.

'This invention relates to a fluid-actuated pump apparatus, and more particularly, but not by way of limitation, to a fluid-actuated bottom hole pump for oil wells and the like. This application is an improvement on applicants co-pending application Serial No, 764,668, filed on July 30, 1947.

Itv is an important object ofv this invention to provide a fluid-actuated bottom hole pump for oil wells which will provide a positive working stroke with the utilization of either oil, water or gas as a power uid.

'Another object of this invention is to provide abottom hole hydraulic pumping unit which includes a reciprocating piston element the movement of which is controlled by a valving mechanism which includes a pilot valve to control the position of a. main valve wherein the movement ofv said pilot valve is accomplished by the travel of `the piston element and wherein the position of said pilot valve is maintained throughout the eiected piston travel by high-pressure fluid acting thereagainst into Which pressure the pilot valve connecting rod must be moved to eiiect the reversal of the main valve and the subsequent reversal of the piston element.

,And still another object of this invention is to provide a hydraulic bottom hole pumping unit where the input supply pressure is constantly maintained on one face of the engine piston and wherein a regulated exhausting pressure relief from the opposite face'causes the movement o'fvv ofthe piston in one directionand wherein the controlledow of supply iiuid pressure directed against said opposite face of the engine piston becomes effective upon therpiston. rod to cause the movement of the piston element inthe opposite direction. f

And still another object of this invention is to provide a bottom hole fluid-actuated pumping unit utilizing a valve mechanism contained within the engine piston for regulating and causing the reversal of the reciprocating stroke of the piston and wherein said valve mechanism includes a pilot valve whose position can be altered by the continued travel of the engine piston into a. positionto cause a reversal of the supply fluid pressure relationship that is actuatingfthe engine plungers movement prior to the completion of said reciprocation oi the pump plunger in either direction.

.fAnd still another object of this invention is to provide a bottom hole duid-actuated pump for oil vwells having a valve controlling the stroke of the piston and which includes a pilot valve for controlling the position of the control valve mechanism and wherein the pilot valve is initiallymoved by supply inlet pressure prior to any change of position of the control valve. And another object of this invention is to provide a fluid-actuated pump having supply pressure fluid constantly maintained on one face of the engine plunger and a regulated pressure directed to the opposite face of the engineplunger to cause a Working stroke, and wherein said. supply pressure during one stroke of the engine 4plunger is disposed at both sides of the plunger to provide a balanced pressure condition.

And still another object of this invention is to provide a fluid-actuated pump for. oil wells and the like, wherein the piston element is reciprol 5.-cated by constantly maintained supply pressure 'fluid in such a manner that there is a balanced pressure condition within the engine piston cylinder on one stroke of the plunger whereby the plunger is moved against the flow of supply pressure iiuid, while on the opposite stroke of the` piston there is an exhaust at one end 0f the 5' gine-piston moves throughY oneA of;its zpow'er:Vv

plunger permittingv movement 'of the pistonby l supply pressure liuid.

And still another object'of this invention is to provide a' fluid-actuated pump having constantly maintained supply pressure on one face ofthe,`

engine piston and wherein the engine cylinderv cavity adjacent an opposite face of said piston is alternately iilled with supply pressure fluid toV y cause one reciprocalv movement, and the exhaustling. of saidspent supply fluid directed through anengine piston rod and into the pumping column.

p vAndstill Aanother object of this invention is to provide auid-actuated bottom hole pump for oil wells having an engine piston and a pumping piston wherein supply pressure fluid is contantly maintained against one face of the engine piston,

and wherein spent power fluid is exhausted from an opposite face through the piston and into contact withrthe'upper face of the pump piston for washing any debris, or abrasive foreign material y carried in the pumped fluid into the pumping col- Y umn at a displacement rate of speed in excess i? of; the pump piston speed.

' And an4 additional obj ectV of vthis invention' isA to'provide afluid-aCtuatedv pump wherein an enl- A further object of this invention is to provide strokes without any spent or exhausted power fluid leaving the piston cylinder, and where the combined fluid displacement of a complete piston cycle is effected during a sequent reversal or back stroke of the piston.

A further object of this invention is to provide a hydraulically driven deep well reciprocating pumping apparatus in which the valve mechanism is so arranged that all passageways, ports and seating faces necessary for the complete.. function of the valve parts are contained within the valve assembly, and wherein movement of one part of the valve assembly causes a reversal of the motive fluid pressure thrust reacting upon another part to move said part in the opposite Vdi. rection.

A further object is to provide a pumpingunit in the manner described in which all the reciprocating elements of the unit are flexibly articulated one to the other so that a minimum regard for specic alignment of parts is necessary, and wherein the threaded connections of the piston rod to the engine and pump piston are protected from the fatiguing stresses caused by misalignment and the normal vibrations incident to reciprocal movement.

A further object of this invention is to provide a hydraulically driven deep well reciprocating pumping apparatus of the so-called insert type wherein both the engine and pump cylinder barrels are allowed a full iloating position within the engine and pump jackets, and wherein O ring gaskets or other similar iiexible sealing elements are employed'to maintain a fluid tight relationship where necessary.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

Fig. 1 is a sectional elevational view of one form of the pump unit.

Fig. 2 is an elevational view with certain parts in, section showing the pump unit disposed'in an oil well bore.

Fig. 3 is a schematic view of the mechanism showing at least one disposition of the various parts with the main valve in one seating position.

Fig. 4 is a similar view showing the main valve in a seating position opposite to that shown in.

Fig. 3.

Fig. 5 is a sectional elevational view of atmodified form, but showing the main valve in a position opposite to that shown in Fig. 1.

Fig. 6 is a view similar to Fig. 2, showing an adaptation of the modified embodiment in Fig. 5in an oil well bore.

Referring to the drawings in detail and particularly Figs. 1 and 2, the pump unit 2 comprises an outer sectional housing or cylindrical jacketv 3 having an upper apertured head 4 and an intermediate apertured head 5 connecting the opposite ends of the housing 3. A lower cylindrical housing 3a is secured at its upper end to the intermediate head 5 and at its lower end to an apertured plug or head 6. The upper head 4V is provided with a downwardly extending circular flange 1 for receiving the upper end of an yin` ner cylinder 8, securedvat itslower end to an upwardly extending circular collar 9 secured in anysuitable manner to the, intermediate head 5. The inner cylinder 8 is spaced from the outer cylinder 3 to provide af,passageil/.mzY or annulus 75. maintaining theconnectioni the tubular mem- LO ring sealing velement 6a.

lowed a certain axial movement between the plug I0. The lower end of cylinder 8 loosely engages the collar 3, and at its upper end is in snug engagement with flange 1. Any suitable ring gasket Ia is indented in flange 1 to form a fluid tight joint. The cylinder 8 may have slight radial movement at its lower end, and is allowed a certain axial movement. The head 4 is providedwith a threaded bore II` for receiving a string of macaroni tubing I2 adapted to extend to the top of the well (not shown) and permit suspension of the pump unit 2 in the well tubing I3 arranged in spaced relation with the well casing I4 (Fig.4 2).

The lower endof the tubing I3 is provided with acollar I5 having a seating nipple I6 secured thereto. The bottom plug 6 is provided with a tapered outer periphery I'I for supporting the pump unit 2 on the nipple I6 in the well tubing I3. Circular sealing ,gaskets I8 are provided below the tapered periphery I1 and are disposed to seat in the nipple I6. The bore Ilof head 4 Ais in communicationwith a vertical passageway I9-in turn communicating with the annulusY It through a-port 20. They collar!) is provided with a 4port 2I providing communication between the passageway II) and a piston chamber 22 ,prof vided by cylinder 8. A circular piston unit Pf is disposed in the chamber 22 and comprises an outer sleeve 23 connecting with the engine valve manifold 24 of slightlysmaller diameter, which in turn is connected with main valve housing 25V of still smaller diameter. A main valve-unit 26 is disposed within the housing` 25 and'is provided with an extension valve 2-'I adapted Ato cof operate with an apertured seating member 93 provided between the members 23,v 28 and.24.1 The crossover member 28 is4 provided with'. a..

downwardly extending collar 29 to which is secured a tubular rod3ll spacedfrom sleevel 23v and extending through the piston unit P, collar 9, the apertured intermediate plug 5 and into connection with a lower pumping piston PL The apertured plugy 5 is provided with any suitable packing 32 encirclingr the tubular member 30 providing a seal ybetween the chamberl 22 and:

a lower chamber 33 in whichis disposed'the piston unit P'.

The lower head 4I5 is provided with ashouldered bore 34 in which is provided a valve seat 35 -held .therein by a valve cage 36 threadedly-secured in the lbore 34, and in which is disposed-a ball valve 31 acting as an inlet standingV valve for Y the pump unit 2 as will be hereinafter set forth.

The pump piston unit P' is disposed in chamber Y 33 provided bythe sleeve 3| loosely fitti-ng the lower flange of the plug 5 at its -upperend, and

forming a exible but iiuid tight contact with the upper flange of the lower plug 6. The upper flange of plug 6 is indented to receive agasket such as .an

The sleeve 3 I is almembers 5 andjS. The piston lunit P comprises and inner cylinder 38 threadedly secured between an upper collar 39k and a lower collar 40. An outer sleeve 4I is also secured between the collars 39'and 40. A' valve s-eat42-is supported by the collar 40. The inner sleeve 38 is provided j with shoulders 43 for maintaining a valve cage 44 therein, which in turn is provided with a ball"V valve 45 acting as a` traveling valve within theV Furthermore, a locking col-` ber .ai with the piston unit P'. The eonar 'se has a split tapered extension beyond the threads engaging asimilar tapered bore in nut 46 to rmlysecure the tubular member 30. Like members are' provided in the engine piston assembly which when made up relieve all vibrational stress from the threaded make-up at each end of the rod member 30.

The' main valve 26 is provided with a centrally disposed recess 48 in which is slidable a pilot valve 49'.v` The pilot valve is provided with a pilot valve rod extending upwardly through a sleeve bearing 5| disposed in the upper apertured portion of the housing 25. 'I'he pilot rod 50 is coupled with a pilot extension rod 52 through collar member 53, and the extension rod 52 extends upwardly into the lbore 54 of the head 4.

The bore' 54 is provided with an apertured shouly der 55 for a purpose as will be hereinafter set forth. The upper end of the extension rod 52 extends through the apertured shoulders and is :providedfwith a stop nut locking device 56. The rod'52 and nut 56 are disposed in a tubular member58 closed at the top end 59 and threadedly secured at its lower end in the bore 54 to provide a chamber 60 for a purpose as will be hereinafter set forth. The collar and nut members are of two-piece construction so devised as to provide a split tapered and female threaded member to seize the male threads of the rod when the male threads of said rod draw the mating members tapered faces into interference.

The extension valve 21 is provided with a vertical. passageway 6| communicating with a forked passageway 62 in turn communicating with vthe recess or bore 48 of the main valve 26. In like manner the pilot valve 49 is provided with a vertical passageway 64 communicating with a transverse passageway 65 in turn communicating with a chamber 66 above the main valve 26. The lower :portion of the main valve 26 is spaced from the sleeve 25 to permit a slight clearance thereby. providing a passageway 68 in communication with atransverse bore 69 in the main valve body 26. The outer periphery of the valve 26 above the passageway 69 is provided with sealing rings to prevent fluid leakage to or from the chamber 66. The outer periphery of the piston unitP is provided with a plurality of vertical- Y ly spaced piston rings 12 and in similar manner the piston unit P' is provided with a plurality of vertically spaced rings 13. 1 Y.

I The main valve manifold 24 has a central bore into which opens the port 85 andvis vadapted to receive valve seating collar 83 at its upper termination and a similar' valve seating collar 93 at its lower termination. Interposed between collar v83 and the main valve housing 25 is an apertured ring ||6 establishing communication between the central bore of manifold 24 and the port 88 when the main valve is in one position.v Valve seating collar 93 is adapted to form a fluid tight engagement with the crossover member 28 by seating into and against a recess provided at its upper end thus providing fluid passage from port 11 to the central bore of manifold 24.

Operation macaroni tubing I2 where it is discharged through the passageway |9, port 20 and into the annulus I0 and through a port 2| into chamber 22. The piston unit P is provided with a port 15 directing the power fluid into chamber 16 and through a passageway or port 11 provided in the crossover member 28, and into contact with the lower face of the extension valve 21. When the pilot valve is in an upward position as shown in Fig. 3, the supply pressure uid may discharge through passageways 6|, 62 into chamber 48, passageway 64, ports and into chamber 66 above the main valve 26 thereby assisting the seating relationship of the extension valve 21 with its valve seating collar 93. With the pilot valve 49 and the main valve 26 disposed in this position as shown in Figs. 1 and 3, the supply pressure fluid in chambers 22` and 16 will cause movement upwardly of the piston unit P. A circular bearing or guide member 89 is in threaded engagement with main valve housing 25 and acts as a locking device with member 24. The guide 88 is provided with a plurality of circumferentially spaced apertures 8 I.

Upward movement of the piston unit P will displace any power fluid present in chamber 82 above the piston unit P through the apertures 8| and the passageway 84 provided by the annulus between the inner periphery of the barrel 8 and the outer periphery of the

members

25 and 24. The spent power fluid from chamber 82 is discharged through the passageway 85 and through the annular space between the reduced neck portion 86 of the extension valve 21, and the opening in the valve seating collar 83 and thence through the apertured ring ||0 into the exhaust passageway 88, in turn communicating with a port 89 in the crossover member 28 which is in communication with the tubular member 30 for discharge through port 90 and into a chamber 9| provided between the tubular member 30 and the valve cage 44, and hence outwardly through a port 92 into the chamber 33. It will be apparent that the upward movement of the motor piston unit P will cause a simultaneous upward movement of the pumping piston unit P' to displace fluid present in` It will be apparent during the upward movement of the piston unit 3| the traveling valve 45 precludes any flow of power fluid into the chamber 98 below the pumping piston unit P', at the same time relieves pressure against the standing valve 31 to allow the production fluid from the well to flow into the chamber 98 for a subsequent displacement.

As the piston unit P moves upwardly the constantly sustained supply pressure fluid in the main valve recess 48 maintains the pilot valve 49 and

rods

50 and 52 in their fully extended position until the upper face of the coupling collar member 53 contacts the underside of the shoulder 55 disposed in the bore 54, thereby arresting further upward movement of the pilot valve rod and the pilot valve. However, the supply pressure fluid will cause continued upward movement of the piston unit P and the main valve 26 to a point where the discharge ends of the passageways 62 are closed off by the arrested pilot valve 49. Simultaneously correspondence is provided between the chamber 66 and the exhaust port 69 in turn communicating with the exhaust passageway 88- -through the annulus 68, thereby relieving thel acs-,1.1m-

supply-fluid pressurecondition inphamber 66.V In this condition supply fluid pressure constantly reactingv against the cross sectional area of the extension valve member 21 will move the main valve upwardly away from valve seat 33 past port opening 85 and into forcible contact-with valve seat 83. With the Valve 21 moved to its-upper position as shown in Figs. 4 and 5,7the supply` pressure fluid from

chambers

22 and 10, port 11 will discharge through port 85 into passageway 84, apertures 8|, and into the Ichamber 82 at the top of the piston unit P.

Supply fluid pressure is established in chamber 60 above'the pilot rod assembly by passing by the loosely fitting member 53 and its recess 54 and the nut E Aand the bore of the tube 58. Assoon as the pressure in chamber 82 is increased sumcientlyV it will cause movement of the motor piston unit P in adownward direction with a simultaneous downward movement of the pump piston P' to cause displacement of production fluid disposed inl chamber 98 through the travelingrvalve 45, pOIt 92 and into the chamber 33. It will be apparent that a portion of the iiuid may be displaced through the

ports

94 and 86 and into the pumping column 91. During the downward stroke (Fig. 4) of the piston units P and P the standing valvev31 is seated to preclude any flow of` thewell fluid in chamber 98 into the production strata. It is apparent that downward movement of the piston units P and P is accomplished without a pressure exhaust relief against the lower facey 19 of the piston P since the constantly maintained supply pressure in chamber 22 is` balanced bysupply pressure now existing in chamber 8,2above the piston unit. However, the difierential area'provided by the tubular rod 38 causes the downstroke of the motor piston unit P and the pumping piston P'; It will be apparent from the above that during the downstroke of the piston unit P there is no exhaust condition in the chamber 22, but the piston unit P is moved throughl and against the flow of the constantly maintained supply pressure fluid.

As the motor piston unit P is caused to move downwardly (Fig. 4) by the power huid, the power-,fluid in chambers Sii and 82 also acts against the cross sectional area of the pilot rod extension 50 to cause a simultaneous movement of the pilot valve rod, andthe pilot valve 88 until the upper nut'iabuts theupper face of the shoulder 55 thereby arresting any further downward movement of thepilot valve 48. However, downward movement of the motor piston unit P and the main valve 25 is continued. The continued downwardmovement of the piston unit after the pilot valve assembly has been arrested alters the relative position of main valve to pilot valve porting; closing chamber 8E to exhaust corresponderme by the movement of thepilot valve over ports 6% and in simultaneous sequence opening the porting of passageways 82to chamber 48. By virtue. of this continued movement the chamber V(it above the main valve is in correspondence with supply uid pressure. It will be apparent that with an increased pressure condition in chamber 6B the larger area of the main valve 26 relative to the extension valve 21 will cause movement of the main valve 20 downwardly to seat the extension valve 21 forcibly against the valve seating collar 93 thus precluding correspondence oi the Y power fluid beyond this point of seal. This downward movement of the main valve establishes direct `correspondence between chamzabove the piston unit?. by, War-0f portage 8|, 84, 85, through Uvalveseat 83, apertured ringv IIO,

ports

88 and 88 into and throughthe pis-Y ton rod 30 towards the lower pressure condition of the pumping column.. Consequently the l movement of the motor piston unit P is ,reversedl one position to another, and is maintained inV either position by the supply pressure fluid acting thereagainst. Furthermore, the movement of the pilot valve is always into or against a high pressure condition. Furthermore, it is arrested.'

in its movement by the shoulder-55 prior to ,any

movement .of the main Valve 26 and its extensionv valve 21 for controlling the intermittent discharge of inlet huid to the chamber 82 causing a downstroke of the piston units P and P. It is to be further noted that the length of the pilot rod Vdetermines the complete pilot valve stroke and that the depth of cavity 48 accommodates the complete pilot valve movement plus the movement of the main valve with a sufficient clearance in addition thereto.

meet divers operating conditions. This relationship of ports therefore assures that the pilot valve at either end of its travel, held in said position either by a pressure differential reacting thereagainst or confined by the interference shoulders 55 will either alter or maintain the pressure relationship influencing the main valve position as the case may be, regardless of abnormal or out ofphase positions such as `do occur during installations or nonpredictable bottom hole conditions. It will be apparent that in this manner there is a more positive operation of the pilotv valve to assure a responsive movement of theY main valve. i

In Figs 5 and 6, is shown a modication of the invention which is particularly adaptediora wire line installation in the well bore. The pump apparatus shown in Fig. 5 is substantially the same as that shown in Figs. 1 to 4 inclusive, except that it is modiiied to eliminate the outer jackets 3 and 3c ofthe preferred embodiment; and the passage of the power fluid through the apertured head 4 and the passageway I0. It will be apparent that the elimination of the vouter jackets provides a pump of smallerA diameter which may be utilized in smaller sized tubing. yet provides for substantially the same volume of fluid displacement as that disclosed in the preferred embodiment,V or a larger diameter pump in the same size tubing for greater volume. Furthermore, the placement and removal ofthe pump unit in the well bore by any suitable Wire line apparatus (not shown) expedites the placement of the pump without the necessity of utilizing the Astring of macaroniA tubing I2.

In Fig. 6, is shown the modified pump unit 99 disposed in the tubing string I3 wherein a lower section of tubing. |00 is coupled by a collar I 0I to the lowermost end of the tubing string I3., Furthermore, the section |00 is connected with a lower section, I02,'through coupling collars |03 and |04 interconnected by ay seating nipple |05 threadedly secured at the collars. A cylindrical seating nipple |01 is threaded Vto the-lower collar |06'V and extends downwardly therefrom into threaded connection with a lower nipple 10851111- pprted .by, an :aperturedplug/,or conventional loil- Thus it is evident that av desirable portage over-travel can be provided to.

.the well by the wire line apparatus,

este wellpacker |09.. disposed inthe casing I4. The

pump unit 99"of..reduced`diameter is modied i. further to provide a plurality ofvertically spaced .sealing rings II'I ,disposed on the outer periphery of .the intermediate. plug 5. I I I are adapted to contact the inner Vperiphery of the seating nipple |05. It will be apparentthat vouterl housing for. the unit `99 is substantially the same as cylinders. 8` and 3| of the preferred em- The sealing rings bodiment with a modification of the plug 5.

Furthermore, the intermediate plug 5 of the modication is provided with an inlet port H2.

AThe top tubular member. 58 is provided with a projection or ange member H3 adaptedto receive any suitable type wire line hook member (not shown) providing for insertion, seating and removal o f the pump unit from thetubing string. Theh low'ermost apertured 'plug 6... of the preferred embodiment'is modified in the disclosure -of Fig. 5 byproviding a seating nipple H5 ex- -ten ding downwardly therefrom. A circular ring" 'II`8,of inverted L-sliape ini'crosssectionis disposed below the plug 6 'and slidable upon'the nipple H5; and-is'maintained therein by a circular shoulder 'I I1 provided on the outer-periphery ofthe nipple. A lower collar H8 is'thread' edly secured to the ring H6. The collar H8 is provided with tapered or angled end portions I I9 for seating the pump unit 99 into the angled portions |20 ofthe seating nipple |01. The collar H8 isprovided with an aperture |2|.

From the above it will be apparent that the pump may be run into the well tubing I3 on any suitable wire line connecting with the. flange I I3,

not shown, and the tapered portion I I9 seats on the nipple |01 simultaneous With the rings III contacting the inner periphery of the nipple |05 in a'uid tight seal. With the pump in position las shown in Fig. 6, high pressure supply uid from the top of the well (not shown) is discharged through the tubing I3 into the annulus |22 and through the inlet port H2 and into the vchamber 22. Ity will be apparentfthat the operation of the main valve 210, pilot valve 1|9,` motor piston P, and pumping 'piston P is substantially the same as that shown in the preferred embodiment in Figs. 1 to 4 inclusive.

When it is desired t remove the modified pump unit 99 from the Well by a wire line and jar apparatus (not shown), the pump unit is lifted or j arred upwardly allowing the sleeve I I to slide slightly upward on the L-shaped ring H6 there- -by unseatingthe bottom of the collar H5 from the collar I AIt! and placing the chamber 25pbelow the tapered seat in correspondence With'the pumpingcolumn through. the port |2|. The annulus |29 is providedwith a port |23 Icommunicating with the annulus |24 between the tubing I3 and the casing I4 dening the pumping column of the displaced Welluid. As the pump unit 99 isflifted the hydrostatic head of fluid. inthe pumping column will flow through the port I2I into the chamber below the unit 99 thereby balancing the pressure at both sides of vthe unit to aiord an easy withdrawal of the unit from The initial movement ofthe-collar H5 does not of necessity unseat from the tapered portion |20 of the nipple |01, however,v after the balancing of pressure in chambers |25 and |29, continued pulling by the Wire line apparatus will unseat the tapered portions H9 of collar H8 as Well as the cups III from the nipple |05V to remove the unit 99 from the well. It will be apparent that the tapered seatportion H9` may be modiiied in a manner (not shown) such asA the use of a straight nipple of reduced diameter and having suitable sealing cups encircling the nipple for afluid seal with the inner periphery of the nipple |91.

" 9,9' is of'rejduced' diameter from that s hownjin the preferred embodiment to permit the use of L smaller size'tubing; Furthermore; it will heapparent .that the reduced diameter ofthe'unitl 99 will Permit Merger pump'to te unused m standa'd Size Jfflllving to provide an increase-d dispute@V `.ment of wellfluid. i n

Changesmay be made in the combination and arrangement of parts as heretofore set forthin the specification and shown in the drawings, it being understood that any modification in the precise Lembodiment of the invention may be made within the scope of the following claims without departing from the spiritcf the invention.

I claim:

- 1. A duid-actuated pump comprising, Vin combination: a motor cylinder, a pump cylinder and a piston reciprocable in each cylinder; a piston rod interconnecting .said pistons; .said pump cylinder having a, suction inlet and a discharge outlet for pump fluid; said motor cylinder having an inlet for operating fluid and a discharge outlet for spent operating fluid, said last-named discharge outlet including .a'passagew-ay extending axially `through s aid piston rod and communicating. with said pumpcylinder, whereby spent oper- -ating fluid from saidmotor cylinder is discharged in to and through said cylinder and through said pump fluid discharge outlet.

2. A uid-actuated pump comprising, in com bination: a motor cylinder, a pump cylinder and a piston reciprocable 'in each cylinder; a piston rod interconnecting said pistons; said pump cylinder having a suction inlet and avdischarge outlet for pump fluid; said motor cylinder having an inlet for operatinggnuid and a discharge outlet let for spent operating iiuid, said last-nameddischarge outlet including tj-passageway. extending axially through'said piston-rod and-communicating Withsaid pump cylinder; whereby spentoperating fluidfrom said motor cylinder is Ydischarged into and through said pump cylinder and through said pump fluid discharge outlet; and valve means, operable in response to predetermined reciprocal movement of said motor piston for controlling the application of operating fluid pressure to the-opposite ends of said motor piston and for controlling-the discharge of spent operating fluid vfrom said motor cylinder through said pump fluid discharge outlet.

3. A duid-actuated pump comprising., in combination: a motor cylinder, a pump cylinder and Y a piston reciprocable in each cylinder a piston rod interconnecting said pistons; said pump cylinder having a suction inlet and a discharge outlet for pump fluid; said motor cylinder having 'an inlet for operating uid and a discharge outlet for spent operating fluid, said last-nameddischarge outlet'including a passageway extending opposite ends of said motor piston and for con` trolling the discharge of spent oper-ating uid fromsaid motor cylinder through said pump iiuid discharge outlet.

4. -A fluid-actuatedV pump comprising, in combination; a motor cylinder, a .pump cylinder and' .a piston reciprocablegneach. cylinder; a piston Vrod interconnecting said pistons; Vsaid pump cylinder.. having a. suction' inlet .andra discharge .outlet for pumpfluid; said motor cylinder having an.- .inletJ for-...operating huid. at one. side of vsaid .motor piston; said motor piston having a valvecontrolled "rst fluid passageway Vtherethrough adapted, when open, to by-pass operatingiluid fromsaid oneside to the opposite' side of said piston; said motor cylinder having a dischargeV outletv for spent operating Vfluid including a valvecontrolled second fluid passageway in said lmotor piston and a passageway extending axially through said piston' rod and communicatingsaid second iiuid passagewaywithsaid'pump. cylinder,

whereby spent operating fluidfrom saidmotor cylinder `is discharged into and through said pump cylinder and through said pump 'fluid discharge outlet.

'5. A fluid-actuated pump comprising, in combin'ationz .a'motor cylinder, a pump cylinder and a piston reciprocable ineachy cylinder; a piston rod interconnecting Ysaid pistons; said pump cylinder Yhavingl a suction inlet and a discharge outlet for'pump'luid; said'motor cylinder havingan inlet for'operating-:fluidat one side of said-motor piston; said motor^piston having a va'lveecontroiled iirst iiuid passageway therethrough adapted, when open,to by-passoperating uid from lone side'to` the oppositeside of said; piston; said motor cylinderhaving a d ischarge outlet for spent operating- 'fluid including a valve-controlled second lfluid passageway in said motor Vpiston and a passagewayextending axially through said piston rod and communicating said second fluid passageway with said 'pump' cylinder, whereby spentoperatingiuidfrom said lmotor cylinder is discharged into `and through saidl pump cylinder and 'through saidy pump. iluid discharge outlet; and `valve meansoperablein'reponse to predetermined reciprocal 'movement of said motor piston `to alternately open oneiof saidtpiston passageways and `close thev 'otherfpiston :passage- Way.

6. A fluid-actuatedlpump comprising; in combination: a motor cylinder, `a pump cylinder'and a piston reciprocable in each cylinder; .a piston rod interconnecting said pistons; said pump cylinder having a suction inlet'and a discharge outlet for pump fluid; said motor-cylinder having an inlet for operating fluid atone side of said motor piston; said lmotor pistonA having Aa valvecontrolled vi-lrst liuid passageway therethrough adapted, when open,.to by-pass operating uid from said .oneside tothe opposite side of said piston; said motor cylinderV` having va discharge .outlet for spent operating fluid including a valvecontrolled-second'uid passageway in said motor 'piston and a vpassageway extending axially through said piston rod and communicating'said 75 .second fluid passageway `with said .pump cylinder,

whereby spent Aoperating Ailuid .from saidmotor cylinder is discharged kinto and through lsaid pump cylinderandfthrou'gh said'pump fluidzdisy.charge outlet, and valve meanscarried'by. said .motor piston and'operable in response' topre determined reciprocal movement ofv saidimotor piston to alternately openoneof said piston vpasrod interconnecting said pistons; saidpumpcylinder having a suction inlet and' a discharge outlet vforpuinp fluid; said motor cylinder'having i an .inletfor operatingfluid'and a'dis'charge outlet for spent operating fluid," said last-named Ldischarge outletzincluding ai passageway' extending .axially through saidpiston rod andcommunieating with `said pump cylinder,VA whereby spent' operating .iiuid from said motolfl-jcylinder `is l"discharged intoand` through said pump cylinder'and through said pumpfluid dischargeA outlet; Iiluidactuated main' valveI meansY carried by` said motor piston for controlling the application of operating luidjpressure to opposite ends of said -motor piston and for -controlling the discharge of spent operating iiuid from said motor cylinder;and pilot valve .means carried 'by' said motor'piston vand 'operable in response to predetermined reciprocal movementA of said motor piston to actuate said main valveA means.

8. A duid-actuated pump comprising, in combinationz'a motor cylinden'a pump rcylinder'and a piston reciprocable in each' cylinder; ya piston rod `reciprocable in' each cylinder; said pump cylinder having suctioninlet means and discharge outletmeans for pumpv uid ;v` said motor cylinder ton rod andcommunicating with said pump cylinder adjacent a pumping face of said'pump piston,

ywhereby during la pumping stroke --a stream. of spent operating iiuid is discharged into'said pump cylinder adjacent said pumping face of said pump .piston to agitate and remove -in suspension any sand or other solids which may have accumulated on said pump piston.

Y9. A fluid-actuated pump comprising, inY combination: a motor-cylinder, a pump cylinder and a piston reciprocable in each cylinder,l each vpiston dividing its respective cylinder into` upper-and lower chambers ;Y a piston rod'interconnectingsaid pistons; said pump cylinder having suction inlet means and discharge outlet means for pump iiuid; said motor cylinder having inlet meansffor'operating iiuid and discharge outlet means for spent operating iiuid, said last-named dischargeoutlet means including a passageway extendingl axially through said piston rod and communicating` with said upper pump chamber-adjacent the lower end thereof, whereby during the upward pumping stroke a stream of spent operating fluid is discharged into said upper pump chamber .adjacent the upper surface of said pump'piston to. agitate and remove in suspension any sand or other solids which may have accumulated Aon'saidV pump piston.

10. In a fluid-actuated deep well pump, `the combination of: a double-actingmotor including a cylinder and a motor piston reciprocable-therein, `said piston having oppositely directed' faces of -diierent4 areas; the 'smaller of saidVr faces :being adapted to be in continuous open communication with a source of operating fluid; a pump including a cylinder and a pump piston reciprocable therein; a piston rod interconnecting said pump and motor pistons, said rod having a fluid passageway extending axially therethrough and communicating at one end with said pump cylinder; and valve means carried by said motor piston and operable to provide communication between the larger of said motor piston faces and, alternately, said source of operating fluid and said fiuid passageway in said piston rod.

11. In a, Huid-actuated deep well pump, the combination of: a double-acting motor including a cylinder and a motor piston reciprocable therein, said piston having oppositely directed faces of different areas, the smaller of said faces being adapted to be in continuous open communication with a source of operating fluid; a single-acting pump including a cylinder and a pump piston reciprocable therein, said pump piston having a by-pass passage therethrough and a check valve in said passage adapted to close said passage during one stroke and to open said passage to by-pass pump uid through said piston during the oppo- Y site stroke; a piston rod interconnecting said motor and pump pistons, said rod having a fluid passageway extending axially therethrough and communicating at one end with said pump cylinder at the discharge side of said check valve; and valve means carried by said motor rpiston and operable to provide communication between the larger of said motor piston faces and, alternately, said source of operating fluid and said uid passageway in said piston rod.

12. In a duid-actuated deep well pump, the combination of: a double-acting motor including a cylinder and a motor piston reciprocable therein, said piston having oppositely directed faces of diiierent areas, the smaller of said faces being adapted tobe in continuous open communication with a source of operating iiuid; a single-acting pump including a cylinder and a pump piston reciprocable therein, said pump piston having a by-pass passage therethrough and a check valve in said passage adapted to close said passage during one stroke and to open said passage to by-pass pump iiuid through said piston during the opposite stroke; a piston rod interconnecting said motor and pump pistons, said rod having a fluid passageway extending axially therethrough and communicating at one end with said pump cylinder at they discharge side of said check valve; main valve means carried by said motor piston and operable to provide communication between the larger of said motor piston faces and, alternately, said source of operating fluid and said fluid passageway in said piston rod; and pilot valve means operable in response to movement of said pistons to control operation of said main valv means.

OSCAR E. DEMPSEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,118,547 Carlisle May 24, 1938 2,287,779 Carlisle June 30, 1942 2,451,560 Knowles Oct. 19, 1948 2,473,864 Coberly June 21, 1949 2,497,348 Ecker Feb. 14, 1950 2,544,094 Knowles Mar. 6, 1951