US2654221A - Pumping jack oil makeup and pressure control - Google Patents

Description

Oct. 6, 1953 F. H. RUED 2,654,221

PUMPING JACK OIL. MAKEUP AND. PRESSURE CONTROL.

Filed May 16, 1950 INVENTOR. Fra' h. IPuza' Patented Oct. 6, 1953 UNITED STATES 'PATENT OFFICE PUMPING JACK OIL MAKEUP AND PRESSURE CONTROL Fred H. Rued, Lafayette, Calm, assignpr to The Pelto'n Water Wheel company, San'Fra'ncisco, Calif., a corporation of California Application May 16, 1950, Serial No. 162.;221

7 Claims. 1

My invention relates to pumping jacks-for use generally in connection with pumping deep oil wells and isparticularly concerned with a pumping jack of the general type shown in the patent of Kyle and White, 2,325,138, issued July 27., 1943 and in the co-pending application of Ira Morgan White, Serial No. 32,629 filed June 12, 1948 and entitled Hydraulic 'Pum'ping Jack Control, now Patent No. 2,617,256, and in the co-pending application of Ira Morgan White, Serial No. 114,180 filed September 6-, .1949 and entitled Hydraulic Pumping Jack Now PatentNo. 2,575,241.

in hydraulic pumping jacks of this type thereis a balancing tank designed to receive a quantity of oil and a quantity of air both under pressure. The oil from the balancing tankis transferred by a force pump to a cylinder and piston arrangement which actuates the pump. The'oil transfer proceeds alternately in opposite directions under the control of a reversing valve. In common with most hydraulic machinery, various leakages and oil spillages occur during the operation of the structure. It is quite necessary to maintain a supply of oil in the balancing tank and preferably the supply of oil is maintained substantially ata fixed amount despite losses from the system.

It is therefore an object of my invention to provide a mechanism for supplying to the balanc ing tank an amount of oil to make up for escaped and leakage oil.

Another object of my invention'is to provide means for maintaining a pre-determined level of oil in the balancing tank.

A still further object Of my invention is to provide means for maintaining in the balancing eral to improve hydraulic pumping jacks.

An additional object of my invention is in general to improve pumping jack oil make-up and pres-sure controls.

Gther objects, together with theforegoing, are attained in the embodiment -o'f-myinvention described in 'the accompanying description and illustrated in the accompanying drawing. The drawing is a diagrammatic representation of a pumping jack oil make-up and pressure con= trol inits usual environment in a pumping jack of the nature identified. Parts of the figure are :broken away to reduce its size and complexity :andrce'rtain parts are illustrated in cross section on planes of symmetry.

While the pumping jack oil make 'up and pressure control or my invention can be incorporated in various different ways depending upons urrounding circumstances and can be modified withinw-ide limits to'accommodate itself to various different engineering requirements, it has successfully been operated in'accordance with the present disclosure. In this arrangement there is provided a hydraulic pumping jackcylinder 6 shown) In order that the piston may be reciprocated within the cylinder 6, there is afforded a source of operating pressure in the nature of a main oil .pump a diagrammatically shown, and driven in any suitable way by-adriving shaft 9. The-pump :8 is provided with a pair of inlet openings H and" and an outlet f3. The pump is preferably of thefpositive displacement type and operates continuously. The pump inlets H and 12 are connected by a manifold 14 leading to spaced ports l6 and H in 'a reversing valve generally designated '18. The outlet l3 of the pump is likewise connected'by'a'duct '19 to a central port 2| in the reversingvalve l8.

Within the reversing valve-is a valve shuttle 22 having an appropriate contour SO that it can be shifted axially between one extreme position, illustrated, and-an "opposite extreme position in order to provide various interconnections. in the position shown, the inlets H and I2 are connected by the manifold M to the port I! which in turn communicates through the reversing valve with an oil admission port 23. This is joined by a duct 24 toth'e lower portion of a balancing tank 26. This tank is preferably spherical inficontourancl contains a body 21 of oil and a volume 28 of air.

Oil fromthe balancing tank 26 flows through the duct 24 and into the inlet ofthe main pump 8. In the position of the transfer or reversing valve shown, the pump outlet I3 is connected through the pipe I!) and the port 2| with an intermediate port 29 joined by a pipe .3! to a connection 32 at the lower end of the cylinder 6 beneath the piston therein. Thus, as the reversing valve is positioned in the illustration, oil is transferred from the body 21 and put under greater pressure beneath the piston within the cylinder ii. The piston is thus lifted.

As the piston rise it ventually uncovers a line 33previously"subjecte'o'l to substantially atmospheric pTS'SuT'e and suddenly subjects Sllfih line to the'pumping pressure. There is (sense-'- queasy-e. communication of the higher pressure through a check valve 34 and through a line 86 into an end connection 31 in a pilot valve generally designated 38. The pilot valve 38 is, because of the incidence of higher pressure on its enlarged end adjacent the connection 31, transferred or shifted to its opposite extreme position and diverts pressure oil from one of its two ports 38 and 48 into a line 42 leading to a control port 43 in the end of the reversing valve l8. This translates the shuttle 22 into its opposite extreme position. Discharge oil from the shuttle valve 38 flows through port 44 and 46 into a drain lin 41. When the shuttle 22 is translated as described, the connections in the reversing valve are such that the connecting pipe 3| permits oil to leave the cylinder 6 as the piston therein descends and to return through the port 29 and the port I6 into the inlet ll of the main pump 8. At the same time, the pump pressure port 2! is connected to the port 23 so that there is a return oil fiow through the line 24 back to the balancing tank 26.

When the piston within the cylinder 6 descends to its lowermost position, it travels over a pipe which previously has been subjected to pumping pressure but after it is passed by the piston, is subject to substantially atmospheric pressure. A check valve 52 in the lower end of the line 36 permits flow from such line into the cylinder above the piston and relieves the pressure on the end duct 31 of the shuttle valve 38. This valve then translates into its opposite axial position, as illustrated in the figure, and restores the connections to their previous arrangement so that the shuttle 22 of the main reversing valve also is restored. The parts are thus returned to the cycle beginning as previously described and the piston within the cylinder starts its upward stroke again. During the cycle, the pressure transferred through the port 43 of the reversing valve fluctuates between a low value and a high value. Also during the cycle, the translations of the shuttle valve and of the reversing valve and. the operation of various other instrumentalities provide a small amount of oil which is released from high pressure to low pressure. This oil, known as scavenge oil, is returned to an appropriate point in the system joined to the drain line 41 leading ultimate y into the balancing tank 26.

An oil reservoir or scavenge tank 56 is normally operated at substantially atmospheric pressure and is provided with an oil filter or breather 58 to keep out dust and unwanted atmospheric particles. Preferably, a scavenge line 51 extends below the normal oil level within the scavenge tank and passes through a check valve 59 and a normally closed hand control valve 68 to join the drain line 41. In addition, there proceeds from the scavenge tank 56 at a point above the oil level a second scavenge line 6| which passes through a check valve 62 into the drain line 41. Joining the drain line 41 is an overflow line 63 from a compression chamber 64 at the upper end of the cylinder and from which flows oil previously discharged onto the top of the reciproeating piston. Such oil flows through the line 63 into the drain line 41.

All of the accumulated material in the line 41 and its connections both liquid, such as oil, and gaseous, such as air, is drawn through the line toward a scavenge pump 66 of the kind shown in Patent No. 2,575,241 of Ira Morgan White, above identified. This pump is mechanically driven and is effective to pump air, oil or a mixture thereof is varying quantities. The pump 65 f lfccs such mixture through a line 61 provided with a check valve 68 into a connection 69 preferably disposed at the top of the balancing tank 26. The oil and air are separated by gravity in the balancing tank. This constitutes the main return of scavenge oil and the supply of make-up air to the balancing chamber. The oil level therein is indicated by a sight glass 1!.

The amount of oil which is returned through and by the pump 56 is a variable amount. In the initial starting of the system, the manual valve 60 is opened and sufiicient oil from the sump tank 56 is withdrawn through the check valve 59 for charging the system. Subsequently, the valve 68 is closed and the line passing through it is therefore blocked. So that there will be adequate oil return through the line 63 and through the lines 44 and 46, the amount of air which passes through the line BI is greatly restricted by an orifice 12. During the normal operation of the pump 66 a lower pressure exists within the line 41 and 6| than exists in the scavenge tank 56. In this fashion, residue oil is returned and some new air drawn in through the breather 58 and into the balancing tank.

For new oil to take the place of oil which is completely lost from the system and so does not flow through the scavenge pump 66, I provide an oil make-up and pressure control arrangement.

A body 81 is provided with a pair of cylindrical bores 32 and 33 of difierent diameters. Within the bore 82 there is reciprocably disposed a piston 84 having packing rings 85 and provided with a reduced collar 86 and a head 81. A cross passage 88 is drilled through the collar and a head opening 89 communicates with the cross passage. At its other end, the piston has an enlarged head 9! constituting a stop and a seat for a return coil spring 92 also resting against a shoulder 93 in the body 8!. A closure cap 94 seals the upper chamber while a closure cap 96 seals the lower end of the body. An inlet port 91 is connected by a duct 98 to the line 51 while an outlet port 88 is connected by a duct it! through a check valve 182 to the line 41. In addition, a port I83 is joined by a pipe I84 to a connection with the line 42 extending between the pilot valve and the reversing valve and once per cycle subject to a pressure fluctua- With this arrangement, as the reversing valve shuttle 22 reciprocates back and forth under the influence of fluctuating pressure in the line 42, this pressure is communicated in a cyclic fashion through the pipe I64 and the port 103 into the upper cylinder 83. When a high pressure is imposed upon the chamber, the eflect is to displace the piston 84 downwardly compressing the spring 92 and causing the piston to overtravel the port 91. Oil within. the volume of the bore 82 below the passage 89 is transferred by the reduction of such volume, through the passage 88 and into the port as and through the pipe i l! and check valve [02 into the return line 41. Oil within the chamber 82 is thus restored to the balancing tank.

When the reversing valve shifts its end position and the pressure in the line 42 is correspondingly dropped in a cyclic fashion, there is a similar reduction of pressure within the chamber 83. The spring 92 is then efiective to restore the piston 34 to its original position. Normally this would, in enlarging the chamber 82, reduce the pressure within the line 16! but the check valve 12 prevents that and there is no back flow through the line IOI T e r u t on in pressure is communicated men of on within the reserve or. 's'cavengetank. 56, the

.check valveifiepreventingbackflowfirom 'theliine "41. Atmospheric .p'ressur'e "forces reserve oil into the. chamber. 82. beneath the .piston,icha-rg'ing!the make-up pump "for a subsequent .stroke. L'When the reversing valve shuttleZZ is again reciprocated and pressure is again imposed upon 'the l'ine 'I'IT I, the piston '84 is driven downwardly againandaniother charge of make-up oil is transferred through the scavenge .pump 6 6 into the balancing tank :26.

L'For each cycle or stroke of the mainpumpinggiack 6, a definite or predetermined amount. oft-additending ultimately to the scavenge tank 56. An

auxiliary blowdown line I I 6 controlled by a hand valve I I1 is also provided.

In normal operation, the hand valve I I1 is closed and the hand valve I I2 is open and the pressure regulator H3 is set to relieve any pressure in excess of the desired amount. If the pressure within the balancing chamber 26 exceeds the desired value, such pressure causes a fluid flow (not necessarily liquid) through the pipe III and through the pipe H4 back to the scavenge tank. If the oil level in the body 21 is below the top of the standpipe III, the fluid flow is air exclusively. The air travels into the scavenge tank 56 but is released through the breather 58 thereof to the atmosphere. If the body 21 of oil is excessive in amount and stands above the upper end of the pipe III when the excess pressure is relieved, then the flow through the pipe III is oil exclusively. The liquid then flows through the pipe H4 into the scavenge tank 56 and joins the body of oil therein for future make-up purposes. The pressure in the scavenge tank is always maintained at atmospheric value because of the breather 58.

If the level of oil 21 fluctuates near the top of the overflow standpipe, then a combined discharge of oil and air may take place through the lines I I I and I I4 until the pressure drops to a value permitting the valve H3 to close and stop the flow. Any air oil mixture flowing through the pipe I I4 travels into the scavenge tank 56 and by gravity separates therein, the oil being retained in the general sump or body of oil therein while the air escapes through the breather 58 to the atmosphere.

By the provision of this structure, therefore, I have provided a make-up oil pump which is efiective once a cycle to transfer from a reservoir of oil a predetermined volume or quantity of oil into the balancing tank. I likewise provide a means for maintaining the fluid pressure within the balancing tank at exactly the desired value and for releasing from that tank not only any air that causes excessive pressure but likewise any excessive oil. There is always retained within the balancing tank a minimum or pre-determined amount of oil at a set level. No air is released below the desired pressure. With this arrangement, the scavenge pump 66 takes care of the return of variable flows or amounts of oil which are used and *releasedf to lowf'pressure parts "or the system during normal operation and supplies make-up 'air 'wh'er'eas the make-up oil pump "introduces to "the system "new .oil tojmake up for losses due to lpackingleakaige, spillage and the like.

What is claimed is: g

1. -A pumping .jack oil. make-up .and'pressiire control comprising a balancing tank adapted to contain oiland a'inajack cylinder, a piston reciprocable in said cylinder, a "first pump for transferringoil between said jack cylinder and said tank, a valverespons'iveto the position of said piston in said 'jack cylinder for regulating the directionv of said oil transfer, a second oil pu-mp, means fo'r operating said second'oil-pump intime with and in response to the operation of said valve, an oil reservoinoil conduits between said reservoir and said second oilspump and between said second-oilpump and-said balancing tank, and an oil overflowpipedisposed with one end at a predetermined level in said balancing-tank and extending between said balancing tank and said :reservoir.

2. A pumping jak oil make-up and pressure control comprising a balancing tank adapted to contain oil and air, a jack cylinder, a piston reciprocable in said cylinder, a first pump for transferring oil between said jack cylinder and said tank, a reciprocating valve, means responsive to the position of said piston in said jack cylinder for reciprocating said valve in accordance with the reciprocation of said piston for regulating the direction of said oil transfer, a second oil pump, means for operating said second pump in response to the operation of and in accordance with the reciprocation of said valve, an oil reservoir, oil conduits between'said reservoir and said second oil pump and between said second pump and said balancing tank, an oil overflow pipe disposed with one end at a predetermined level in said balancing tank and extending between said balancing tank and said reservoir, and a pressure regulator in said overflow pipe.

3. A pumping jack oil make-up and pressure control comprising a balancing tank adapted to contain oil and air, a jack cylinder, a piston reciprocable in said cylinder, means for cyclically transferring oil from said balancing tank to said cylinder and vice versa, an oil sump tank, a reciprocating oil pump, an inlet line connected to said oil sump tank and to said oil pump inlet, an outlet dust connected to the oil pump outlet and to said balancing tank, and means for reciprocating said oil pump through one cycle each time said cyclically transferring means transfers oil from said balancing tank to said cylinder and vice versa.

4. A pumping jack oil make-up and pressure control comprising a balancing tank adapted to contain oil and air, a jack cylinder, a piston reciprocable in said cylinder, a first pump for transferring oil between said jack cylinder and said tank, a valve for controlling the direction of the oil transfer, means responsive to the position of said piston in said cylinder for actuating said valve, an oil sump tank, a reciprocating oil makeup pump, conduits connecting the inlet of said make-up pump to the oil in said sump tank and the outlet of said make-up pump to said balancing tank, and means responsive to the operation of said valve for reciprocating said oil make-up pump.

5. A pumping jack oil make-up and pressure control comprising a balancing tank adapted to contain oil and air, a jack cylinder, a piston reciprocable in said cylinder, a first pump for transferring oil between said jack cylinder and said tank, a valve responsive to the position of said piston in said cylinder for controlling the direction of the oil transfer, a sump tank, a conduit for carrying oil from said valve to said sump tank, a scavenge pump, an outlet from said scavenge pump to said balancing tank, a conduit for transferring oil from said sump tank to the inlet of said scavenge pump, a duct for carrying air to the inlet of said scavenge pump, a make-up pump for transferring oil from said sump tank to said balancing tank, an overflow pipe from said balancing tank to said sump tank, and a pressure regulator in said overflow pipe.

6. A pumping jack oil make-up and pressure control comprising a balancing tank adapted to contain oil and air, a jack cylinder, a piston reciprocable in said cylinder, a first pump for transferring oil between said jack cylinder and said tank, means responsive to the position of said piston in said cylinder for controlling the direction of the oil transfer, an oil make-up pump, means for driving the make-up pump by the transfer oil and in response to the direction of *8 the transfer, means for supplying said make-up pump with oil, and means for conducting oil from said make-up pump to said balancing tank.

7. A pumping jack oil make-up and pressure control comprising a jack cylinder, a piston reciprooablc in said cylinder, means for supplying said cylinder with oil under pressure to reciprocate said piston cyclically, an oil make-up pump driven by said oil under pressure in time with the reciprocation of said piston, a source of oil, a conduit for conducting oil from said source of oil to said make-up pump, and a conduit for conducting oil from said make-u pump to said supplying means.

FRED H. RUED.

References Cited in the file of this patent UNITED STATES PA'IENTS Number Name Date 2,299,692 Goehring Oct. 20, 1942 2,325,138 Kyle et a1 July 27, 1943 2,336,808 Simon Dec. 14, 1943 2,489,412 Harvey Nov. 29, 1949 2,504,218 Noll et a1 Apr. 18, 1950

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