US2218215A - Air balance for pumps - Google Patents

Description

` c; M. O'LEARY 2,218,215

f AIR BALANCE Fon PUMPS original Filed Marca 18, 195s '2 sheets-sheet 1- oct. 15, 1.940.

Patented ocr. 15, 1940 y UNITED STATES AIR. BALANCE FOB PUMPS Charles M. OLeary, Houston, Tex. Continuation of abandoned application Serial No.

196,753,l March 18,`

1938. This applicationv February 17, 1940, Serial N0. 319,565

' 16 Claims.

This invention relates to an air balance for pumps, especially deep well pumps, and the present application is a continuation, and is led in the place and stead, of applicants abandoned 5 application, Serial Number 196,753, which was originally led March 18, 1938.

VIn the operation of deep well pumping mechanism it is usual'to provide a constantly rotating driving unit which acts through a vertically oscillating walking beam to longitudinally reciprocate the pump rods extending down into a well. It is evident that under such circumstances unequal load conditions will prevail upon the downstroke and the upstroke of the pumping mechanism, thusacting to impose unequal resistance to the driving torque 'of the prime mover. This is due to the fact that on the upstroke of the pumping mechanism the pump rods are under tension since the walking beam must lift the weight of the rods and that of the column of liquid which is being raised, while on the downstroke the weight of the rods aids in the movement of the pumping mechanism. Of course, during both of the above strokes, the operating crank connected with the walking beam will produce a variable torque drive in its cycle of operation.

Various means have been provided for compensating for these inequalities, such for instance' as weights, compressible iiuids and incompressible liquids, but in every instance weights and combinations of uids and liquids as well as liquids alone, practical objections havebeen found in use. In the present instance the desirable cushioning and counterbalancing action are obtained by the use of a compressible fluid, such as air, used alone.

It is the principal object of the present invention, therefore, to provide a counterbalance means adapted to be operated in conjunction with the walking beam of a pump, and which counterbalance means will automatically act to maintain a constant predetermined pressure of uid to cushionthe downstroke of the well pumping mechanism, and to aid in elevating the pump load onv the upstroke, the said structure providing means whereby a desired fluid pressure may be established' within the apparatusand automatically maintained, and also means whereby the spacing of the pump rods within the well may be reset.

'I'he present invention contemplates the pro vision of a combined pneumatic counterbalancing unit which comprises a balancing cylinder and 55 piston, and a storage cylinder communicating (Cl. 'J4-589) therewith in a manner -to automatically control the uid pressure in bothv cylinders and to establish and regulate the pressure of uid in either. I l

The invention is illustrated, by way of exam- 5 ple, in the accompanying drawings, which form a part of this specication, and in which,

Figure 1 is a view in side elevation showing a pumping unit of the type in which thepresent invention is used and shown, and, 1

Figure 2 is an enlarged view in central vertical section showing the unit of the present invention. Referring Amore particularly to the drawings,

I0 indicates la frame structure carrying suitable 15 bearing standards Il upon whicha, drive shaft I2 is rotatably supported. The drive shaft carries a pulley or sprocket I3 suitably connected with driving means, and also carries a crank I4. This crank is fitted with a pltman rod I5 pivotally attached at I6 to a walking beam Il. The walking beam is provided with a pivot pin I8 carried at the upper end of a Samson post I9. At the free end of the walking beam a fitting 20 is provided to receive reins 2I of pump rods 22 which 25 reciprocate within a well 23 and operate a pump piston 24.

'Disposed at some point between the base I0 and the walking beam I1, and here shown as being positioned between the free end of the walking 30 beam and the base, is an air cushioning unit 25.` This unit is fitted adjacent its lower end with horizontally disposed trunnions 26 mounted in a bearing structure 2l and has at its upper end a piston rod 28 pivotally connected at 29 to the 35 walking beam.

Referring particularly to Figure 2 of the draw.- ings, it will be seen that the air cushioning unit A25 comprises the piston rod 23 previously mentioned, which depends from. the walking beam 40 and carries a piston 29 at its lower end. This piston reciprocates within a balancing cylinder 30, here shown as being disposed within a closed air cushioning tank 3|. The upper end of the balancing cylinder 30 is closed by a head 32 and 45 carries av s'tuillng gland 33 by which the piston rod 28 is packed.`

The lower end of the balancing cylinder is provided with a head 34 towhich a pipe 35 is connected. This pipe extends downwardly 50 through the bottom of the tank 3| and is fitted with a manually operable valve 36. Below valve 36 is a pipe 31 carrying a tee 38 to the opposite sides 4ol which are attached return -pipes 39. These pipes communicate with the bottom of the pipe 5l carrying nectedwithapipei! leadingtothetank 3|. Ihetank 3|, and when the valve 36 is opened, they permit the air within the balancing cylinder 3l, and beneaththe piston 29, to be forced from the cylinder into the tank.

The bottom of the cylinder 3|I is also fitted with a draw-ofi pipe 40, which pipe carries a manually controlled bleeder valve 42. Valve 42 is mounted at the end of the pipe 40, and when opened will allow air to be expelled from the bottom of the balancing cylinder alone, assuming that the valve 36 has been previously closed.

Due to the fact that the balancing cylinder is fitted at its upper end with a closed head 32, a compression space will be formed therein above the piston 23, as well as beneath said piston. These spaces are indicated at 43 and. respectively, and the upper space 43 is fitted with a pipe 46 which leads to a T 46 and conducts air from space 43 to a point outside tank 3|. Attached to one end of T 46 is a pipe 43 carrying check valve 43 which may permit an inflow of air from the atmosphere.

'I'he opposite side of T 46 is provided with a a check valve 5|, in turn concheck valve 5| permits the iiow of air to-the tank, but not from it.

In order to regulate the tank 3|, a T 6|! is placed in is tted with a pipe 6| which connects with a valve housing 62. This valve housing has a lower opening normally establishing communication between the pipe 6| and the atmosphere through pressurewithin the a port 65' in the upper portion of a diaphragmV housing 65. A valve element 63 is mounted within the housing 62 and may move to an obstructing position to close the opening into diaphragm housing 65 and cut oi-the pipe 6| from communication with atmosphere. A diaphragm 64 is mounted in the housing 65 immediately below valve housing 62 and is attached to a valve stem 66 which carries the valve element 63. Fluid l pressure from the pipe 52 against the lower surface of the diaphragm 64 holds the valve in a normally open position.

A spring 61 compressed 64 acts to close the valve when a pressure below a determined minmum` has been reached in the tank 3| with which pipe 52 communicates. Thus reduced pressure in the tank 3| will automatically act to valves 49 and 5| to function in pumping; air into the tank 3|. I

In operation of the form of the invention here shown and described, the r'st step is the closing of valves 42 and 36. Valve 63 will be closed. As the piston 29 reciprocates on its downstroke it will draw air from the atmosphere through the check valve 49 and through pipes 48 and 45 to the compression space 43. On the upstroke of the piston 29, this air will be forced through the pipes 45 and 50 to ,and through the check valve 5|, after which this air under compression will be forced through the pipe -521 into the tank 3|. This will build up the pressure in the tank 3| and in the compression space 44 of the balancing cylinder, or in the tank only, if valve 36 is closed and valve 42 is opened.

When the pressure has reached a denite amount, the pressure-regulated valve 63 will be opened by the force of the pressure against the diaphragm 64, and thereafter the piston 29 will merely displace the air in the compression space 43 lby forcing it through pipes 45 and 6| and through -the valve housing 62 to the atmosphere.

the pipe line 45 and above the diaphragm close the pipe 6| and cause the checkk On the downstroke, air will be drawn inwardly tothe upper compression space 43 throughthe 'opened valve housing 62.

When it is necessary to set the pistox 23 in any desired positionwithin the cylinder 33, this may be accomplished by closing valve 36 and permitting airto escape through valve 42 from the compression space 44 of the cylinder. During the 0peration of the pumping mechanism, on the downstroke the piston 23 will be moved downwardly as the pitman rod I6 'forces the driving end of the walkingbeamllupwardly. Thisdownward movement of the piston will be resisted by air under pressure as it is displaced from the com pression space 44 through the pipes 35 and 33, into the tank 3|, and since the air is a compressible fluid, a pneumatic cushioning action will be produced. This cushioning action will tend to coun- 'terbalande the weight of the. pump rods as they move downwardly into the well. On the upstroke of the piston, at which time the pump rods and a column of liquid are being lifted within the well, the expansive action of the compressed air within the tank will act upon the balancing piston 23 to aid in lifting the piston and the load of liquid with it.

It will thus be seen that by the counterbalancing construction here disclosed it is possible to establish a predetermined counterbalancing and cushioning air pressure within the balancing unit,

' as an incident to theoperation of the pumping mechanism, and to thereafter maintain this air pressure at a predetermined value in direct relationship tothe counterbalancing and cushioning action desired.

While I have shown the preferred form of my invention as now known to me, it will be understood that various changes may be made in the combination, lconstruction and-arrangement of parts, by those skilled in the art without departing from the spirit o'f the invention as included in the following claims.

Having thus fully described my invention, I claim as follows:

1. VIn a well pump o f the type including a power actuating walking beam,an air-balance comprising a balancing cylinder .closed at its opposite ends, a piston reciprocating in the cylinder and forming upper and lower compression spaces therein, a, piston rod connected at its lower end with said piston and extending through the up- Vper closed end of the cylinder, means pivotally mounting the lower end of the cylinder upon a fixed base, means pivotally connecting the upper end of the piston rod with the walking beam, a cushioning tank means freely connecting the lower compression space of the cylinder with said tank, a conduit connecting the upper compression space of the cylinder with the tank, and valve controlled means for said conduit whereby iluid within the upper compression space of the cylinder may be delivered into the cushioning tank when pressure within the latter falls below a predetermined point, and vented to the atmosphere when pressure rises above said point.

-v 2. In a well ppmp of the type including a power actuated walking beam, an air balance comprising, a balancing cylinder closed at its opposite ends and mounted `for rocking movement, a piston reciprocating in the cylinder and forming upper and lower compression spaces therein,

. a piston rod connected at its lower end with said rod with the walking beam, a cushioning tank, means freely connecting the lower compression space of the cylinder with said tank, a conduit connecting the upper compression space of the cylinder with the tank, valve controlled means for said conduit whereby fluid within the upper compression space of the cylinder may be delivered into the cushioning tank when pressure within the latter falls below a predetermined point, and vented to the atmosphere when pressure rises above said point, and means for permitting air to be drawn into the upper compression space of the cylinder upon the downstroke of the piston.

3. In a well pump of the type including a power actuated walking beam, an air balance comprisingabalancing cylinder closed at its opposite ends and mounted for rocking movement, a piston re-l ciprocatinginthecylinderand forming upper and lower compression spaces therein, a piston rod connected at its lower end with said piston and extending through the upper closed end of the cylinder, means pivotally connecting the upper end of the piston rod with the walking beam, a cushioning tank, means freely connecting the lower compression space of the cylinder with said tank, a conduit connecting the upper compression space of the cylinder with the tank, valve corrtrolled means for said, conduit whereby uid within the upper compression space of the cylinder may be delivered into the cushioning tank when pressure within the latter falls below a predetermined point, and vented tothe atmosphere when pressure rises above said point, and automaticmeans for permitting air to be drawn into the upper compression space of the cylinder upon the downstroke of the piston.

4. In a well pump of the type including a power actuated walking beam, an air balance comprising a balancing cylinder closed at its opposite ends and mounted for rocking movement, a piston reciprocating in the cylinder and forming upper .and lower compression spaces therein, a piston rod connected at its lower end with said piston and extending through the upper closed end of the cylinder, means pivotally connecting the upper end of the piston rod with the walking beam, a cushioning tank, means freely connecting the lower compression space of the cylinder with said tank, a conduit connecting the upper compression space of the cylinder with the tank, Valve controlled means for said conduit whereby uid within the upper compression space of the cylinder may be fed underpressure into the tank, means for permitting air to be drawn into the upper compression space of the cylinder upon the downstroke of the piston, and means controlled by pressure within the tank and acting to automatically vent the air from the upper compresi piston and extending through the upper closedend of the cylinder, means pivotally connecting -the upper end of the rod with the walking beam,

a cushioning tank, means freely connecting the lower compression spa-ce of the cylinder with said tank, a conduit connecting the upper compression space of the cylinder with the tank, valve controlled means for said conduit whereby Vuid within the upper compression space of the cylinder may be delivered into the tank, means for permitting air to be drawn into the upper compression space of the cylinder upon the downstroke of the piston, means controlled iby pressure Within the tank and acting to automatically vent the air from the upper compression space of the cylinder when flow of air from the cylinder to the tank is interrupted, and manually controlled means for relieving air from the lower compression space of the cylinder.

6. In a well pump of the type including a power l actuated walking beam, an air balance. comprising a balancing cylinder closed at its opposite ends and mounted for rocking movement, a. piston reciprocating therein, a vpiston rod connected therewith, means pivotally mounting the lower end of the cylinder upon a fixed base, means pivotally connecting the upper end of the piston rod with the walking beam, a cushioning tank, means freely connecting the lower compression space of the cylinder with said tank, a conduit connecting the upper compression space of the balancing cylinder with the tank, valve controlled means for said conduit whereby fluid within the upper compression space of the cylinder maybe delivered into the tank, and means for manually isolating the lower compression space of the cyl-` ton reciprocating therein, a piston rod connected therewith, means pivotallymounting'the lower end of the cylinder upon a fixed base, means pivotally connecting the upper end of the piston rod with the walking beam, a cushioning tank, means freely connecting the lower compression space of the cylinder with said tank, a, conduit connecting the upper compression space of the cylinder with the tank, valve controlled means for said conduit whereby uid within theI upper compression space of the cylinder may be delivered into the tank, and means controlled by pressure within' the tank for venting the upper compression space .of the cylinder to the atmosphere.

' 8. In a counterbalance for a pumping unit having a walking beam, a balancing cylinder *andy a pressure tank in a single unit having a pivotal mounting at its lower end, the cylinder being within the tank and closed at both ends, a piston within the cylinder dividing the same into upper and lower compression spaces, a rod extending from the piston through the upper end of the unit and pivotallyconnected to the walking beam, a pressure conduit between the lower compression space of the cylinder and the tank, and having a portion thereof exteriorly of the tank and provided with a manual cut-off Valve, means for feeding air under pressure from the upper compression space of the cylinder into the tank, and means controlled by pressure within the tank for venting the said upper compression space to the atmosphere without loss of pressure from the tank.

9. In a counterbalance for a pumping unit having a walking beam, a balancing cylinder, a pressure tank, the cylinder being closed at its upper end and in communication at its lower end with the tank, a piston in the cylinder dividing the same into upper and lower compression spaces, a

-otal mounting at its lower end, the cylinder being within the tank with its upper end closed and its lower end in communication with the tank, a piston within the cylinder dividing the same into upper and lower compression spaces, a rod extending from the piston through the upper end of the unit and pivotally connected to the walking beam, means for feeding air under pressure from the upper compression space of the cylinder into the tank, and means controlled by pressure in the tank for venting the said upper compression space of the cylinder to the atmosphererwhereby the compressing action may idle without aecting pressure within the tank.

11. In a counterbalance for a pumping unit having a walking beam, a pressure t-ank, a -balancing cylinder normally in communication at one end with said tank, a piston in said cylinder forming' a working compression space between the piston and the tank communicating endkof the cylinder, means controlled by tank pressure for automatically creating and maintaining predetermined pressure in said tank by piston action during operation of the beam, valve means for cutting oi communication between the tank and the said normally communicating end of the cylinder, and a valved connection between said compression space and the atmosphere whereby pressure may be bled from the said compression space when its said communication with the tank is cut off, without affecting tank pressure.

12. In a counterbalance for a pumping unit having a walking beam, a pressure tank, a balancing cylinder normally in communication at one end with said tank, a piston in said cylinder forming a working compression space between the piston and the tank'communicating end of the cylinder, and means controlled by tank pressure for-automatically creating and maintaining predetermined pressure in said tank by action of saidA piston during operation of the beam.

13. In alwell pump of the type including a power actuated walking beam, an air balance comprising a balancing cylinder closed at its opposite ends and mounted for rocking movement,

a piston reciprocating in the cylinder and forming upper and lower compression spaces therein, a, piston rod connected at its lower end with said piston and extending through the upper closed end of the cylinder, means pivotally connecting the upper end of the piston rod with the walking beam, Ya cushioning tank, means freely connecting the lower compression space of the cylinder'with said tank, a conduit'connecting the uppercompression space of the cylinder with the tank, and valve controlled means for said conduit whereby fluid within the upper compression space of the cylinder may be delivered into the cushioning tank when pressure within the latter falls below a predetermined point.

14. In a counterbalance for a pumping unit Ahaving a walking beam, a pressure tank, a balancing cylinder normally in communication at one end with said tank, a piston in said cylinder forming a working compression space between the piston and the tank communicating end of the cylinder, and means for automatically creating and maintaining predetermined pressure in said tank by action of said piston during operation of the beam including pressure means in direct communication with the tank for rendering said first named means active and inactive.

15. In a counterbalance for a pumping unit having a walking beam, a balancing cylinder, a pressure tank,'the cylinder'being closed at its upper end and in communication at its lower end with the tank, a piston in the' cylinder dividing the same into upper and lower compression spaces, a rod extending from the piston through the upper closed end of the cylinder and connected to the walking beam, means for feeding air under pressure from the upper compression space of the cylinder into the tank, means for cutting off communication between the lower cylinder space and the tank, and means for venting the lower cylinder space to the atmosphere when cut off from the tank, and thus withoutv reducing tank pressure', whereby the piston may be relieved from tank pressure while compressing within the upper space.

16. In a counterbalance for a pumping unit having a walking beam, a pressure tank, a balancing cylinder closed at its opposite ends, a piston in said cylinder dividing the same into compression spaces at opposite sides of the piston, one of said spaces being normally in open communication with the tank, a rod for actuating the saidpiston connected to the walking beam, connections for feeding air under pressure from the other cylinder space to the tank, means for cutting oi said open communication of the first mentioned cylinder space with the tank, and means for bleeding air from said iirst mentioned cylinder space and venting the same to atmosphere when so 'cut oi from the tank, without reducing tank pressure, whereby the piston may ,operate at times without pressure opposition in the said first mentioned space.

:CHARLES M. OLEARY.

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