US2774334A - Reciprocating prime mover - Google Patents

Description

w. H. CLINE, JR 2,774,334

RECIPROCATING PRIME MOVER 2 Sheets-Sheet l 1 wmmw 9 w/u/Lw H. a; we. Jr.

INVENTOR. Z /M Afiorne Dec. 18, 1956 Filed May 1, 1953 Dec. 18, 1956 w. H. CLINE, JR 2,774,334

RECIPROCATING PRIME MOVER Filed May 1, 1953 2 Sheets-Sheet 2 mu IAM H. a; 1M: Jr.

INVENTOR.

United States Patent RECIPROCATING PRIlVlE MOVER William H. Cline, Jr., Houston, Tex., assignor to Hughes Tool Company, Houston, Tex., a corporation of Delaware This invention relates to prime movers of the reciprocatory type and more particularly to a device of this type having particular utility as a drill or tool of the impact type to provide cutting action upon the bottom of an earth bore by a combination of conventional rotation of an earth boring bit on bottom and the simultaneous application of impacts to such bit.

It is an object of the invention to provide a fluid actuated reciprocatory prime mover having improved features of construction and operating characteristics.

Another object is to provide a prime mover of the class described of compact design and limited in am'al extent whereby the device is capable of being readily moved axially of a bore hole formed when the device is used as a well drilling tool.

Still another object is to provide a prime mover which, though of limited physical dimensions, is capable of withstanding rigorous use such as is encountered when using the device as an impact or percussor tool when drilling well bores.

It is also an object to provide a prime mover adapted for use as a well drill of the impact type that is capable of maintaining an efficient rate of drilling while using light weight on the drill where conditions prohibit or limit the use of heavy weight.

A further obiect is to provide a device of the class described which, when used as a well drilling device, will maintain an efficient rate of drilling with relatively light weight on the drill in areas where heavy weight is normally required.

Still another object is to provide a reciprocatory type of prime mover which is fully fluid actuated whereby the use of actuating springs, with attendant difliculties, is avoided.

Another object is to provide a prime mover which, when used as a well drilling tool, will not produce high pressure fluctuations in the fluid proximate the Wall of the well bore, such fluctuations being conducive to caving of the wall.

The invention also comprehends an impact type of well drill capable of imparting impacts to a drill bit on bottom or of oscillating the drill bit to apply impacts at the surface being disintegrated to form hole.

Still another object is to provide a device of the class described, provided with a valving mechanism which travels with and is movable relative to the piston, parts being so constructed and arranged that at a predetermined position of the piston and valve assembly the power stroke is terminated and valving action preliminary to the succeeding stroke takes place as the piston travels to terminal position. v

A further and more specific object of the invention is to provide a fluid actuated device of the class described including a housing having a reciprocable piston therein, said piston comprising an annular upper portion and a peripherally reduced lower portion, there being spaced seals between said respective portions of the piston and the housing, and means for alternately directing pressure ice fluid to the exterior of the piston between the seals and confining the fluid within the piston to produce reciprocatory movement of the piston.

The foregoing objects together with other objects will be more fully apparent from the following descriptions, considered in connection: with the accompanying drawings in which: I

Fig. l is a vertical sectional view through a well drill embodying the invention and showing the parts in their relative position at the beginningof the power stroke;

Pig. 2 is an enlarged vertical sectional view through the upper portion of the device showing the relative posi-' tions of parts at the end of the power stroke;

Fig. 3 is a sectional view similar 'to that of Fig. 2 but showing the relative positions of parts when the piston has reached its lowermost position of travel;

Fig. 4 is a sectional viewsimilar to that of Figs. 2 and'3 but showing the relative positions of parts near the end of the return stroke and when fluid power is applied to move the valve from its seat preliminary to initiation of the succeeding down stroke;

Fig. 5 is a sectional view of the lower portion of the device used as a well drill and showing a modification whereby the drill is of the hammer and anvil type.

In the drawings, showing an embodiment of the invention used as a well drill, the device is shown at 1 and comprises an adapter 2 threaded at 3 for attachment to the lower end of a drill string. The adapter 2 is threaded externally at 4 at its lower end for attachment to the housing or casing 5 made up of an upper section 6 and a lower section 7 threadedly interconnected at 8, such feature of construction facilitating assembly and disassembly of the housing which'encases a piston assembly 10 reduced at its lower end to form downwardly extending piston rod 11 threadedly connected at 12 to a guide bushing 13 to which the bit 14 is secured; Y

A sleeveor tail pipe 15 is secured in and depends from the adapter 2 thus forming. with the surrounding hous-' 'ing 5 a chamber 16 there being a series of openings or nally at 9 so that the end portion of the piston may move beyond the shoulder 19 on the sleeve 15. The lower end of the piston head is secured to the body 21 by threads 22 and such body is reduced in cross section at its lower end to form the piston rod 11. The piston thus comprises an annular upper portion and a peripherally reduced lower portion thereby providing an annular chamber 23' between the piston and the surrounding housing there being spaced seals betweenthe piston and housing to prevent leakage of fluid from within this chamber.

The structure of the piston, as just described, also provides an internal chamber 23 for valve 25 within the piston whereby the valve travels with the piston and is reciprocable therein in such amanner that fluid pumped downwardly through the adapter 2 and into the housing 5, as indicated by the arrow 24, will reciprocate the piston to impart impact energy to thedrill bit 14. In this manner the usual disintegrating action produced by rotation of the drill bit is supplemented by mpacts of the drill bit on bottom. 7 7 v The valve 25 includesvalve stem 26 which terminates at its lower end in the valve head 27 having upper and lower seating surfaces '28 and 29 for engagement, respectively, with'upper and lower seats 30 and 31 on upper and lower seat rings 32. and 33. l

7 though it is to be understood that operation will be initiated regardless of the position of the piston and-valve 'when the actuating fluid is introduced. The force exwithin that portion of the chamber 23'that exists between the sleeve and'the'inner wallof the piston-10;

The, valve piston fits slidably'upon' the upper end of the'valve stem'26 and is rigidly secured thereto by means of cap nut 40. Attention is directed to the fact that the cap nut-'40, the valve'stem 26and the-valve head 27. have an axial passage 41 whereby a passage is of the'valve. 1 V V p The seat. rings 32"and 33 are'par't of a seat ring assembly mounted in l the l'ower endof the chamber 23;

- This assembly'comprises a retainer ring {15 surmounted I provided afall'ti'mes between the upper and lower. sides" by spacerf ring 46;andport ring'47jhaving ports 48, there 'being complemental ports 49 in the-piston thereby providing passageways betweenthe interior and exterior of the piston from between the seatfringsiand-to the chain ber23'..

Another spacer ring 50 rests upon'theport ring'47 and V seat ring 32 fits slidably therein; The entire seat ring assembly is secured in place by means of clamp ring 52' which is engaged by the lower end of the piston head 26 when the component partsfof the; piston are intercom.

n'ected by the threads 22. I V V To minimize shock when the valve moves into-engagement with the seat ring; 33 this seat ring is mounted for limited axial movement uponan annular body 53 of deformable material encasedwithin thech'amber formed by 'the retainer ring 45 spacer ring 46 and the seat ring.

Seatring 32 is likewise mounted for limited axial movement andhas its'upper, end grooved at 55 the central upi standing flange 56 being of a dimension to .slidablymove Within i clamp g 52- This feature of construction provides a dashpot action which together with fluid forces *acting upon the seatring prevent excessive stresses in ;parts of the structure as :a result of the engagement'of the 7 'seat 30 bythe'valvehead127.

a The piston rod 11 passesdownwardly througha guide; and seal rihg60 which formsihe lower 'sealbe'tween' the piston and the housing an'd this'ring also serves as'an abutment for the ring spring fil-engageable by the upper end of the guide bushing 13. 'This'structure serves to resiliently terminate upward movement of the piston and associated elements and to. absorb energyitherefrom and redeliver such energyto'the assembly atthe-beginning ofthe succeeding downward stroke. 5 T

erted upon and producing downward movement of the piston '10 is that produced by the fluid acting upon the 'areaD, the effective area for downward force exerted by During the succeedingdownward.power stroke thefl' valve head 27 is heldupon the seat r ing' 32 by -an'fexcess of upward force'acting' on the area A'over the. downward force acting upon the smaller area, B. QThis condition continues to exist and the power-stroke continues until the valve piston 35 withdraws frorn its telescopic rela tion with the sleeve 15. This 'marks the .end. of the; power stroke and the piston It! continues to travel downy 7 ward underthe momentum previously impartedthereto;

. At this instant the force exerted upon the lower side of;

the valye ring 38 is neutralized bya like forcefuowex erted'upon the upper side of this rin'. Hence; the down wardfluidforce exerted uponthefva'lve head 2;! causes.

the valve to move downwardly andtb: leave thegseat 36 whereby opening 'of :a passage through ithe piston is: initiated. e

The piston assembly Ill continues to. travel downwardly'until the, bit 14 has eifected' impact upon the bottom of thehole' being .drilled, Thus the downward" movement of the piston assembly isterminated but the? momentum of the valve 25 plusthe fluid pressure exerted upon the area B thereof causes rapid closure of the valve upon the seat ring 33; As already explained'the cushion ring 53 functions toresist'shockof closure of the' valve upon the seat ring.

Pumped fluid is now diverted through ,ports 4 8,v491to the chamber 23 Where it exerts an upward force-upon the piston assembly; such force being the difference between the fiuid forces acting upon the areas'E and F, and y atthe same time the valve is'he1d upon the lower valve seat by fluid pressure ac'tinguponflthe .area Bf Hence, the piston assembly moves upwardly on the return's'troke The motivating force continues until the annularluppe'r f end of the piston head '20 clears the shoulder-lg 'at the 5 lower end of the reduced area 18 onthe' sleeve 15.1;ln 'thefmeantime the ringfi rof the valve 25; has entered theannulus between: the interior of the' pistonlil and the' lower end of the sleeve 15. j It is apparent therefore that 7 V at no time is there a'thr'ough passage fromjhe' interior p of the pistonto and through'ports 17 to'the exterior of the housing 5.

The guidebushing 13' hasperipheral splines which fit within,complementarygrooves 66 in? the housing 5.

. "It seems apparent therefore that the drill bit 14 may bei' rotatably driven in. a conventional manner but may also be moved axially jof the jhousing 5 as the piston 10 is acaused'to reciprocate. 1 By virtue of such mode ofroperation'theconventional action of -the'bit .14fupon bottom As already indicated the inventionromprehends a of either the piston or'valve is avoided-and one which will not stall. ,To further describe the disclosed en'ibodimentand explainits operationgattention is directedto the factthat, as shown in Fig. ;.4, the annular area :E of;

' the pistonhead: 2 0 isgreaterfthanatheoverall:area F of structurerinwhich the use or springs-to eflect movement the pistonrodll. Also, the" overallareafC of the;,seati iring fiz ris greater than the annular area A of'the valve p ring AS'and such area A isg iueffective area Bofthe valve head 27..

f It willnow be assumed that thefpartsa1ie in the'relativel positions shown in Fig. 1 when aetuating flnid isdntror "iduced to' the device *asindicated by the arrow 24Qal;

urn; greater thanihc 7 7 pperating conditions. J

7 As soon as the upper end of the piston clears the shoulder 19 difierential pressure is created between thc upper, v and lower surfaces of the valve ring-38. iAt this instant the valve 25 tends to move from engagemenhwith'the valve seat'31 because of the difierential fiuid force acting upon the areas A and B. The kinetic energyoflthe valve' is absorbed, following closure upon the valveseat' :7 j 30, by the differential of force'sactingmpon the areas. C

andA. p v J lnasrnuch asfthe seat ring 32 is mounted for. Jim

formed by ring "52 and the-cooperating grooveSS in the 7 seat ring 32 functions to absorb. excessive kinetic energy which the:valve may possess, at 'times; fr orn' abnormal I LWhen thevalve engages upper seatl'itl th ef succeedin l power stroke is begun. Initial application of power rtogetherfwith the energy absorbediby the'ring s, 'ng'ifil decelerate the piston assembl'y"until it's iveloeity and then' the piston i 's accelerateddownwardly ion the} '1 power stroke in the mannerabove explainedfl F I f e ited,

' axial :movement, 'eflicient absorption of :the kinetic cu: ergy of the valve is"had,:s uch'energy being ahsorbed by f the actuating fluid whereby excessive impact stressesin the valving mechanism are iprevented. The dashpotl.

he distance thatihe piston moves upwardly I :gclearsthe .shoulder 19 on the sle'eve or tail pipe '15 'is the a 'jlea dr of the piston'l .It is durilng this lead'period that a i differential pressure upon the upper and lower surfaces of the valve ring 38 overcomes the fluid pressure upon the area B of the valve and tends to move the valve from the lower seat 31 to the upper seat 30, From flexibility in design the lead may be made very small in which case the valve has insuflicient time to actually move from the lower seat 31 before the piston travel is terminated by engagement with the ring spring 61. In such case the differential pressure tending to move the valve is supplemented by the kinetic energy of the valve to effect closure of the valve upon seat 30.

It seems apparent that this feature in the construction and operation of the device enables great flexibility in operating characteristics of the device inasmuch as operating characteristics may be readily changed by modifying or replacing the sleeve for a selected lead. In this manner compensation may be 'had for the use of various fluids, both gaseous and liquid, and various rates of supply of actuating fluid to the device.

It is to be noted that the valve assembly serves as a barrier within the piston 10 and is operable, with associated valving elements, to alternately confine the actuating pressure fluid within the piston and direct the fluid to the exterior of the piston to advance and retract the piston within the housing 5. Also, the upper annular portion of the piston :16 and the valve 25 co-act with the sleeve or tail pipe 15 in a manner that, at the instant the piston head 26 clears the shoulder 19 on the tail pipe 15, the annular upper and lower surfaces of the valve ring 38 are subjected to the fluid pressure existing exteriorly of the tool. Then, as already explained, the valve assembly begins to move upwardly by virtue of an excess of upward force acting on the valve assembly and, at the same time the piston continues to travel under its momentum to complete its stroke, and efiect the desired impact, if the device is utilized as an impact tool.

it is to be noted also that the ports 17 serve as breather openings to permit displacement of fluids to and from the chamber 16 as the piston reciprocates. Such displacement is subtantially equal and opposite the displacement of the piston rod 11 as it reciprocates and it is thus apparent that the device does not produce high fluctuations in fluid pressure upon the walls of a well bore formed by the tool. This minimizes conditions which tend to produce caving of the walls.

Fig. 5 of the drawings shows the piston rod 11 terminating in a hammer collar 70 which presents an upwardly facing shoulder 7-1 adapted to engage ring springs 61 so that these springs will absorb energy during terminal upward movement of the piston assembly which, in this form serves as a hammer.

The bit 14 is attached to an anvil bushing 72 having splines 73 slidable in complementary grooves 74 in the lower section 7 of the housing 5. A sleeve 75 fits slidably within the housing between the bushing 73 and the spacer ring 76 and this feature of construction per mits the'entire well drill to be lowered to apply a constant downward force upon the bit 14 to induce cutting action thereby. This cutting action is supplemented by impacts from the hammer collar 79 upon the anvil 72 from operation of the well drill mechanism as already described.

Attention is directed to the fact that the device herein described is capable of operation whether fluid is supplied as indicated by the arrow 24 or in the reverse direction. For this reason, when the device is used as a well tool and is being lowered into a well bore filled with liquid,

' operation of the mechanism takes place thus-rapidly filling the drill string with liquid and at the same time preventing the lodging of debris upon moving parts. Conversely, when withdrawing the device from a well bore filled with liquid automatic actuation facilitates drainage of fluid from within the drill string thus eliminating the disadvantages of pulling a fluid filled drill string.

While the disclosed embodiment of the invention is described in connection with its utilitarian application as a well drill of the impact or percussive type it is to be understood that the invention is not confined to such but may be used in any environment where it is desired to convert the energy of a fluid stream to reciprocatory mechanical movement.

Broadly the invention comprehends a fluid actuated re. ciprocatory prime mover capable of converting the energy of a fluid stream to mechanical energy such as impact energy or other energy of reciprocatory movement.

I claim: I

1. In a reciprocatory prime mover the combination comprising, a housing having an inlet at one end thereof for the admission of pressure fluid to the interior of the housing, an annular piston slidably mounted within the housing and having an end thereof peripherally reduced, a depending sleeve at the inlet to the housing forming with the housing an annular chamber, an end portion of the piston slidably fitting within said chamber, there being.

a passage between said chamber and the exterior of the housing, paced seals between the piston and housing, and means for alternately confining pressure fluid within the piston and diverting the pressure fluid to the exterior of the piston between said seals to advance and retract the piston within the housing.

2. In a reciprocatory prime mover the combination comprising, a housing having an inlet at one end thereof for the admission of pressure fluid to the interior of the housing, an annular piston slidably mounted within the housing and having an axial passage therein and an end thereof peripherally reduced, a depending sleeve at the inlet to the housing forming with the housing an annular chamber, an end por-tionof the piston slidably fitting within said chamber, there being a passage between said chamber and the exterior of the housing, spaced seals between the piston and housing, there being a port through the piston wall between said seals, means for closing the axial passage through the piston above and below said port whereby pressure fluid fromthe inlet is alternately V confined within the piston and directed to the chamber exteriorly of the piston and between said seals.

3. In a reciprocatory prime mover the combination comprising, a housing having an inlet at one end thereof for the admission of pressure fluid to the interior of the housing, a piston slidably mounted within the housing and having an axial passage therein and an end thereof peripherally reduced, a depending sleeve at the inlet to the housing forming with the housing an annular chamber, an end portion of the piston slidably fitting within said chamber, there being a passage between said chamber and the exterior of the housing, spaced seals between the piston and housing, a port in the piston wall between said seals, and a valve slidably movable relative to the piston to form a barrier transversely of the piston alternately above and below said port whereby pressure fluid from the inlet is alternately confined within the piston and directed to the chamber exteriorly of the piston and between said seals.

4. In a reciprocatory prime mover the combination comprising, a housing having an inlet at one end thereof for the admission of pressure fluid to the interior of the housing, an annular piston slidably mounted within the housing and having an end thereor' peripherally reduced, a depending sleeve at the inlet to the housing forming with the housing an annular chamber, an end portion of the piston slidably fitting within said chamber, there being a passage between said chamber and the exterior of the housing, spaced seals between the piston and housing, a'port in the piston wall between said seals, and a valve carried by and slidably movable relative to said piston to form a transverse barrier in the piston alternatelyabove and below said port, said valve including meanscooperating with the end portion of the piston slidably fitting within said first mentioned chamber to hold the .valve in position above said port during the downward stroke of the piston.

between the interior and exterior of the piston, a valve mounted on and movable axially of the piston, a valve seat ring slidably mounted within said passage proximate and in advance of said port, and means for holding said valve on the seat ring during the advancing power stroke of the piston, whereby seat ring i subjected to the force of the pressure fluid actuating the piston to absorb kinetic energy of and reduce shock upon the valve at the time of closure of the valve upon the seat ring.

14. In a device of the class described in combination, an annular piston adapted to conduct pressure fluid axially thereof, there being a port communicating between the interior and exterior of the piston, a valve mounted on and movable axially of said piston, a valve seat ring 10 slidably mounted within the piston proximate said port and engageable by said valve to form a barrier to divert flow of pressure fluid to and through said port, and means resiliently engaging said seat ring and operable to absorb kinetic energy of the valve at the time of closure of the valve upon the seat ring.

References Cited in the file of this patent UNITED STATES PATENTS 1,265,133 Sturtevant May 7, 1918 1,605,865 Stevens Nov. 2, 1926 r 1,705,800 Akeyson Mar. 19, 1929 1,964,687 May June 26, 1934

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