US2594577A

US2594577A - Pump and motor therefor

Info

Publication number: US2594577A
Application number: US66435A
Authority: US
Inventors: Arthur E Mcfarland
Original assignee: MCFARLAND Manufacturing CORP
Current assignee: MCFARLAND Manufacturing CORP
Priority date: 1948-12-21
Filing date: 1948-12-21
Publication date: 1952-04-29
Anticipated expiration: 1969-04-29

Description

April 29, 1952 A. E. MCFARLAND PUMP AND MOTOR THEREFOR Filed Dec. 2l, 1948 Patented Apr. 29, 1952 UNHTED STATES ANT FFECE PUMP AND MOTOR THEREFOR Application December 21, 1948, Serial No. 66,435

(Cl. it-150) 17 Claims.

This invention relates to a pump and a motor therefor and refers more particularly to devices adaptable for use in pumping flowable material in predetermined increments and at predetermined time intervals.

Devices of this invention have many uses and by way of example but not by way of limitation, the device may be employed for injecting chemicals known as emulsion breakers into well iiuids containing crude petroleum as it is produced from oil wells. These chemicals break up the water oil emulsions often present in well fluids. It is old practice to inject emulsion breaking chemicals in to the well fluids but difculty has been encountered in accomplishing this inexpensively and yet in such manner as to obtain substantially uniform distribution of the treating chemicals in the produced well fiuids. The; motor may be used for any purpose where it is desired to reciprocate a rod.

An object of this invention is to provide a simple, rugged, low-cost device that will positively pump a iiowable material at predetermined time intervals and in predetermined amounts or increments.

Another object is to provide a device of the character described which may be motivated by fluid under pressure and which may be readily and easily regulated to change the time interval between successive charges or increments of flowable material.

A further object is to provide a device of the character described which may be readily and easily adjusted to change the quantum of each increment of iiowable material that is discharged into another fluid.

Still another object is to provide a motor for chemical injectors or the like. in which the length of the actuating stroke is automatically varied in response to the temperature conditions under which the device is operating.

Astill further object is to provide a motor for devices of the character described which is simple, rugged, inexpensive and yet positive in its action.

Yet another object is to provide a motor for devices of the character described whereinv the time interval of operation' may be readily and easily adjusted.

Yet a further obect is to provide a motor for devices of the character described in which the length of the stroke of the drive part of the motor may be readily and easilyadjusted. v

Other and further objects of this invention will 'appear from the description.

In the accompanying drawings which form a part of the instant specication, are to be read in conjunction therewith, and wherein like referencenumerals are used to indicate like parts in the various views:

Fig. 1 is a top plan view, with parts broken away for illustrative purposes, of a device em` bodying this invention; and

Fig. 2 is a fragmentary view upon an enlarged scalel showing in cross-section the power generating portion of the device shown in Fig. 1.

The device of this invention may be considered as a pump having a motor for intermittently but regularly operating the pump. The motor itself serves as its own timing unit.

Referring to the drawings, a pump head is shown at 5 having a pump chamber 6 therein, which may be an axial bore in which the pump member 'l is adapted to reciprocate to vary the capacity of chamber 6. The pump member 'l preferably is provided with a sliding seal between the wall of the bore and the pump head. A satisfactory seal may be provided by a plurality of conventional Orings 8 fitting in peripheral grooves encircling the pump member l.

The pump chamber 6 is provided with inlet and discharge ports 9 and I8 respectively. Each of these ports should be controlled by suitable check valves. A satisfactory check valve comprises a tubular member Il having an axial bore therethrough with an interior seat surface l2 against which ball valve i3 seats. Spring I4 urges the ball against the seat to prevent back flow of uid through the tubular part.

This valve arrangement may be connected in the inlet port 3 by fitting l5 and have its other end connected to a pipe I6 which communicates with a reservoir for nowable material to be pumped, which isnt shown in the drawings. The same arrangement may be employed for controlling the discharge of the pump head in which case the fitting i5' is connected to the opposite end of part H and threaded in port I0. The dis'- charge pipe Il' is connected to the other end of part i i and Vmay communicate with any fluid container also omitted from the drawings. With this arrangement, it is believed appa-rent that reciprocation of pump member or plunger 'I will serve to alternately draw material through pipe IS into chamber 6 and then to discharge the material through pipe Il into the fluid receptacle.

The motor for reciprocating the pump members 2 r chemical injectingpurposes, operateinte ii predetermined vtime inter- `izafs th a pre 4rmined length 'of stroke.

The actuating mechanism for accomplishing this, in accordance with this invention, is detailed in Fig. 2 of the drawings.

All the actuating mechanism may be housed in a compact housing as a unit made up of a mandrel i8, a sleeve I9 and a nipple part 20, with a pressure chamber 2| secured thereto and preferably welded thereto. Sleeve I9 preferably has an Yeasily broken threaded connection with mandrel IS, which in use may be separated by hand. Nipple 28 is also threadedly connected with sleeve I9 and a seal is provided between these `two parts preferably in the form of an O-ring 22 in a peripheral groove carried by the nipple. A suitable latch 23 prevents accidental breaking of this threaded connection and provides a manually operable, accessible means for controlling the length of the stroke for the end of the nipple limits movementI of the power driven part of the motor as will hereinafter more fully appear. y

The entire power unit housed in the parts just described may be secured in axial alignment with the pump head by a spacer sleeve 24 secured between confronting ends of pump head 5 and mandrel i8 by suitable studs 25.

erally as including a pressure responsive member urged in a direction to produce a suction stroke by a yieldable force. The pressure responsive member is urged in the opposite direction intermittently by a greater force accomplished by the intermittent pressurizing of the chamber in which the pressure responsive member resides by pressure fluid trapped within the pressure dome. The pressure dome is supplied with a pressure fluid at a predetermined rate and when the pressure within the dome reaches a predetermined value, a relief valve mechanism establishes communication between the pressure dome and the chamber for the pressure responsive member. Thus, the time interval of operation depends upon the rate of flow of pressure fluid into the pressure dome. The pressure dome and the chamber for the pressure responsive member are both vented at the end of the power stroke and the pressure responsive member is returned to position for a successive power stroke by the yieldable force.

The fcregoing is preferably accomplished by providing first and second cylinders within the mandrel and sleeve I9 in axial alignment as provided by bores or

cylinders

26 and 21. The pressure responsive member resides in cylinder 21 and may be a piston member 28. This piston is threaded to a plunger 29 and may have a peripheral groove for receiving a seal element 38, preferably a split ring iormed of rubber, neoprene, leather or the like. It is desirable that the piston 2S have a substantial seal within cylinder 21 but that this seal not be absolute in order to facilitate proper venting of the power side of cylinder 21 and the dome.

The pressure dome is provided by the interiors of pressure chamber 2i and nipple 28. This pressure dome opens into the cylinder 21 at the iiared left hand end of nipple 2li as viewed in Fig. 2. In order to close this opening with the piston in its extreme right hand position as viewed in Fig. 2, a part 3l is provided. Preferably a seal is provided between part 3| and the flared end of the nipple which may be in the form of an O-ring 32 carried by part 3| and adapted to engage the iiared portion onipple 26.

This part 3i and seal element 32 may be con- K sidered as a pressure responsive member having an effective area equal to the area enclosed within the seat. This effective area is exposed to pressure within the pressure dome and as this force or pressure builds up, the force tending to drive the pressure responsive member and plunger on the power stroke increases until it is able to overcome the yieldable force which urges the pressure responsive member and plunger in the opposing or seating direction. Immediately upon overcoming this yieldable seating force, the opening between the chamber or cylinder 21 and the pressure dome becomes unobstructed and pressure uid is supplied to cylinder 21 upon the power side of piston 28. This pressure will be substantially the pressure of the dome and due to the larger area of the eiective pressure face of piston 28, the force driving the piston and plunger on its power stroke will be greatly increased to positively actuate the pump member 1. The connection of the pump member with the pressure responsive member will be hereinafter more fully detailed.

Cylinder 21 preferably is provided with two vent ports. Vent port 33 is always open to provide for venting of the cylinder 21 on the side of piston 28 remote from its pressure face. A large port 34 is provided in the wall of the cylinder in such position as to be uncovered by piston 28 as it approaches its full or extreme power stroke position. Port 34 preferably is large so as to quickly exhaust the pressure fluid within the power side or portion of cylinder 21 and the dome. With the pressure dome thus released, the yieldable force urging the pressure responsive member 28 towards its right hand position moves the piston into the position shown in Fig. 2.

The means for providing the yieldable force opposing the power stroke of piston 28 may be any suitable yieldable means, as for example a spring, but preferably and conveniently may be a pneumatic means as provided by cylinder 26. The pressure responsive member within this cylinder is the plunger 29 which is mounted for sliding reciprocation within cylinder 26. A sliding seal may be provided between the plunger and mandrel I8 as, for instance, by an 0-ring 35 in a peripheral groove encircling plunger 29. Cylinder 26 may be pressurized from any suit- 'able source of fluid pressure, but the regularity of operation of the device is greatly improved by supplying the cylinder with a regulated pressure. Opening 3B in the mandrel wall carries a fitting 31 which may be a conduit leading from a suitable source of pressure fluid supply as indicated by regulator 38.

The end of plunger 29 exposed interiorly of cylinder 26 is in eiect a pressure face and the force of the pressure within this cylinder acting against the end of the plunger, drives or urges the plunger on the suction stroke.

The actuating connection between the pressure responsive member 28 and the pump member 1 includes the plunger 29 to which the end of rod or pump member 1 is secured. Preferably this connection is yieldable on the power stroke. A yieldable connection is shown in the drawings in the form of a recess 39 in the end of plunger 29. The threaded end of rod 1 is secured in this recess by nurl 48 threaded in the recess and nut 4I threaded to rod 1 interiorly of the recess. Spring 42 abuts against the end of the recess and the innerside of nut 4I resiliently urging the plunger toward-its power stroke.

Rod 1 extends through the left hand end of mandrel I8, as viewed in Fig. 2, and a seal is pro- 5 vided between the rodi and the mandrel. In the form shown, the G-ring 43- effects this seal and residesina peripheral grooved formedfin rod l.

IEtefei-ri-ng` nowto the pressurization of the pressure dome,- that is, the interiors of' nipple 20 andi pressure chamber 2|, this,` is desirably ac'- complished byproviding arestricted flow bypass between cylinder 2B and theY interior of the pressurey dome. By this expedient, a single source of pressure may beV employed to provide the forces forreciprocating theY pressure responsive member inY both directions. It is also desirable that this bypass beV located interiora-lly of the housing forthedevice tov prevent children, trespassers or the-like from tamperingtherewith and to reduce the likelihood" of accidental breakagei of' the bypass. This may be conveniently provided by forming an opening or passage 44t extending axially of plunger;- 2-9. This passage communicates with the interior ofv cylinder 26 by radial portsV communicatingbetween recess 39 and the exterior of plunger 29; Also the portion of plunger 2'9 immediately surrounding the recess 39- may be of somewhat reduced diameter to: provide for free' flow of fluid into the recess. The right hand end of passa-ge 44 communicatesy with the interior of the pressure dome and a restriction is provided in the passageA to effect; a predetermined rate of chargingI ofv pressure uid into the pressure dome. This restriction preferably isi of an adjustable nature.

A suitable adjustable restriction for4 the flow ofl fluid through passage 44` includes a recess in the right hand end of plunger 29' in which is threaded a sleeve 4E; both ends, the notch on the exterior of the sleeve accommodating a tool to facilitate rotation of the sleeve to adjust its position axially in the recess and the notch on the interior end cf the sleeve providing for flow of uid into the interior of the sleeve past a` ball valve member 41. By adjusting the axial position of sleevevfIIi,` the amount of opening provided between the right yhand end of passage 44 and ball valve 41 may be adjusted to predetermine the rate of flow therethrough. Sleeve 48 may be secured in a set position by manipulation of lock nut 48. A suitable soft gasket 49 seals the joint between lock nut 48, the reduced diameter portion of plunger 29 and the inner periphery of part 3| to prevent leakage of pressure fluid from the pressure dome to the pressure side of piston 28.

To limit the movement of piston 28 in a power stroke direction, a wear washer and cushion, preferably fabricated of a cushioning material such asV leather or the like, shown at 50, i's provided encircling the plunger 29 intermediateY piston 28 and the end of mandrel I8.. In order that the length of the power stroke might be adjusted, a wedge element 5I is mounted to eX- tend into vent opening 33 having its flat or straight surface abutting the end of mandrel I8. The inclined or Wedge surface of the stop will be struck by washer 50 on the power stroke and by advancing' the wedge inwardly or outwardly of the opening, the length of the stroke may be adjusted. t

It is preferable that the stroke be adjustable theremostatically in response to the temperature of the material being pumped. This is true beshould be in order to. properlyV pump, afull. 11.11

Sleeve 46 is notched at crement as desired. For this reason,v the stop 5i is secured to a coiled heat sensitivev element- 52 retained in housing 53,I secured to the exterior of sleeve I9. As the temperature exteriorly of the motor increases, element 52 expands, forcing block or stop '5I further inwardly of the opening 3^3. Obviously, cooling of the atmosphere will cause a slight retraction of the stop. Assuming that the temperature of the material being pumped is. substantially atmospheric, as Where retained in a reservoir exposed to the atmosphere, the length of the stroke will be a function of the temperature of thev material and therefore, the viscosity thereof. It is contemplated that this element 52 could be exposed directly to the material being pumped. The main adjustment for the length of strokev is accomplished manually by adjusting the position of nipple 28 relative to sleeve I9 thereby'determining the limit of movement of piston 28 in cylinder 2l in the right hand direction as viewed in Fig. 2.

It is. believed that the operation of the device ofu this invention is apparent from the foregoing description. The pressure fluid is continuously supplied to the interior of mandrel I8 at a constant pressure The iiuid bleeds through passage 441 past valve 41 at a rate determined by the position of sleeve 46 to pressurize the pressure dome at a predetermined rate. The force of .they pressure within cylinder 26, acting against plunger 29., urges the plunger and piston 28 to its right hand position with seal element 32 and part il sealing off the opening between the pressure dome and the interior of cylinder 2l'. This conditionY will prevail until the pressure within the dome builds up to am degree that the resultant forcev of the pressure across seal 32 is greater than the force. of the pressure Within cylinder 2-5 against plunger 29. When this occurs, the seal 32 will become ineffective and the portion of cylinder 2l on the pressure dome or power side of piston 28- will be energized to drive the piston tothe left as shown in the drawings. As the piston approaches its extreme left hand position, vent port 34 is uncovered, relieving the pressure within the pressure dome and cylinder 21. Withv this pressure relieved, the pressure within cylinder 28- drives the piston to the right, as shown in the drawings, and the pressure dome is again sealed ofi'.

The time interval of operation ofv the motor is adjustable by manipulating sleeve 46. To accomplish this, it is necessary to break the union between mandrel I8 yand sleeve I8 and for this reason,l this union is usually made up only as a finger tight joint. When` this union is brokemsleeve I 9, nipple 2-0 and pressure chamber 2l are removed exposing piston 28. Inasmuch as the piston does not have an absolute seal with cylinder 2l, these parts are readily removed to provide access to sleeve 46. Practically the only wearing part in the entire motor is theseal element 32 and access to this elementv to replace it may behadl in the samefashion. When proper adjustment of ball val-ve 41 has been made or ring 32; replaced, the portion of the housing made up of` the nipple,y sleeveV and pressure chamber arer restored to position and again a finger tight joint is preferredin order to allow easy access for' future adjustment or replacement of the seal element..

There hasbeen provided an automatic adjustment of thestroke of the pump member responsive; toV Aternperature changes exteriorly off the motor in the. forni. of the. thermostatic element 7 52 which governs the position of stop 5|. The stop is abutted by washer 50 upon the end of the power stroke of piston 28 and the position of the stop, in a radial sense, determines the length of the stroke within limits.

From the foregoing, it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having described my invention, I claim:

l. A motor adaptable for connection to a rod for intermittently reciprocating same, comprising a housing, a pressure responsive member in the housing connectable with a rod, said member dividing the interior thereof into a plurality of compartments, one of which is a variable capacity pressure compartment, vent means actuated by movement of said member to vent said pressure compartment at the limit of the power stroke, a means yieldingly urging the pressure responsive member in a direction opposed to the power stroke, a pressure dome with a fitting therefor through which a pressurebiuid may be supplied to the dome at a predetermined rate, and means for establishing communication between the pressure compartment and the pressure dome when the pressure within the dome reaches a predetermined value.

2. A motor adaptable for connection to a rod for intermittently reciprocating same comprising a housing, a pressure responsive member in the housing connectable with a rod, said member dividing the interior thereof into a plurality of compartments, one of which is a variable capacity pressure compartment, vent means actuated by movement of said member to vent said pressure compartment at the limit of the pressure responsive members power stroke, a pressure means l for intermittently reciprocating same comprising a housing, a pressure responsive member in the housing connectable with a rod, said member dividing the interior thereof into a plurality of compartments, one of which is a variable capacity pressure compartment, vent means actuated by movement of said member to vent said pressure compartment at the limit of the pressure responsive members power stroke, a pressure means urging the pressure responsive member in a direction opposed to the power stroke, a pressure dome with a fitting therefor through which a pressure iluid may be supplied to the dome at a predetermined rate, a passage communicating between the pressure compartment and pressure dome, a part carried by the pressure responsive member 'adapted to seat in the passage to clos same with the lpressure responsive member in position to commence its power stroke and to move therefrom to open the passage when the pressure in the dome reaches a predetermined value due to the force of the pressure acting against said part.

4, A motor adaptable for connection to a rod for intermittently reciprocating same comprising a cylinder, a piston mounted for reciprocal movement in the cylinder, vent means in the cylinder adapted to relieve the pressure in the power chamber of the cylinder when the piston approaches the end of its power stroke, a pressure dome adapted to be supplied with a pressure iiuid at a predetermined rate, an opening between the pressure dome and the interior of the cylinder upon the power side of the piston, a relief valve controlling the opening adapted to open upon occurrence of a predetermined pressure within the pressure dome, and yieldable means urging the piston toward its position at the commencement of the power stroke.

5. A motor adaptable for connection to a rod for intermittently reciprocating same comprising a cylinder, with spaced vent and pressure supply openings, a piston mounted within the cylinder for reciprocal movement between the pressure supply opening and vent and adapted to move to a position on termination of the power stroke to place the vent opening in communication with the cylinder upon the power side of the piston, a part carried by the piston and having a lesser cross-sectional area than the effective pressure face of the piston, said part adapted to seat in the pressure supply opening with the piston in extreme position in the cylinder at the commencement of the power stroke, and yieldable means urging the piston in a direction to close the pressure supply opening.

6. A motor adaptable for connection to a rod for intermittently reciprocating same comprising a cylinder with spaced vent and pressure supply openings, a piston mounted within the cylinder for reciprocal movement between the pressure supply opening and vent and adapted to move to a position on termination of the power stroke to place the vent opening in communication with the cylinder upon the power side of the piston, a part carried by the piston and having a lesser cross-sectional area than the effective pressure face of the piston, said part adapted to seat in the pressure supply opening with the piston in extreme position in the cylinder at the commencement of the power stroke, yieldable means urging the piston in a direction to close the pressure supply opening, a pressure dome communieating withV said pressure supply opening, and a tting for the dome through which the dome may be pressurized at a predetermined rate.

7. A motor adapted to have an operating connection with a rod for reciprocating same intermittently at regular intervals comprising a housing with a pressure chamber therein, a plunger in the chamber having a pressure face exposed to one portion of the interior of the chamber to urge the plunger in one direction, a fitting for supplying pressure fluid to this portion of the chamber, two other diierential pressure faces carried by the plunger and adapted when exposed to pressure in another portion of the chamber to urge the plunger in the opposite direction, a pressure dome having an opening into that portion of the chamber to which thelatter faces are'exposed, one of the latter faces adapted to close the opening. with thefplunger in the extreme position towrd which it is urged by the pressure acting agairist the rst pressure face, a fitting for supplying pressure fluid to the pressure dome at a predetermined rate, and vent means for the dome and the portion of the chamber housing the two diierential pressure faces operable with the plunger in extreme position urged by pressure acting against these diierential faces, whereby when the force of pressure in the dome against the diierential face exposed thereto is greater than the force due to pressure against the. rst pressure face the other diiferential pressure face will be energized, the additive force due to pressure acting against the two differential pressure faces positively driving the plunger to vented position from which it will be returned by the pressure operating against the first pressure face.

8. The motor of claim 7 wherein the tting for pressurizing the dome is adjustable to vary the rate of flow of pressure fluid into the dome.

9. The motor of claim 7 wherein an adjustable stop extending into the chamber is engaged by a portion of the plunger to determine the length cf power stroke.

10. The motor of claim 9 wherein the adjustment for the stop includes a heat sensitive element exposed exteriorly of the housing which is connected to the stop and is adapted to automatically adjust the stop to shorten the power stroke as the temperature of the medium to which the heat sensitive element is exposed increases.

11. The device of claim 7 wherein the tting for pressurizing the dome includes a passage communicating between the dome and the portion of the chamber within which the rst pressure responsive face resides.

12. A motor adapted to have an operating connection with a rod for reciprocating same intermittently at regular intervals comprising first and second cylinders mounted in substantial axial alignment, a pressure dome communicating with the second cylinder at its end remote from the first cylinder, fittings through which pressure fluid may be supplied to the pressure dome and the rst cylinder, a plunger extending between and into the cylinders and mounted for axial reciprocation therein, a sliding seal between the plunger and the first cylinder sealing off a pressure face on the plunger exposed to the interior of the first cylinder whereby the pressure within the rst cylinder urges the plunger toward the second, a pressure face carried by the plunger within the second cylinder and exposed to pressure uid supplied thereto by the dome, a part carried by the plunger of lesser area than the pressure face, said part adapted to close the communication between the dome and second cylinder and be exposed to pressure within the dome with the plunger in its position just commencing its power stroke and vent means for relieving the pressure within the second cylinder and dome with the plunger in its other extreme position.

13. The motor of claim 12 wherein the fitting for supplying pressure to the dome is a passage communicating between the interior of the first cylinder and the dome.

14. The motor of claim 12 wherein the fitting for pressurizing the dome is adjustable to vary the rate of flow of pressure iiuid into the dome.

15. The motor of claim l2 wherein an adjustable stop extends into one of the cylinders and is engageable by a part of the plunger to determine the length 0f the power stroke.

16. A motor adaptable for connection to a rod for intermittently reciprocating the same, comprising a housing with a pressure chamber therein, a pressure responsive member in the chamber and connectable with a rod, means for intermittently pressurizing the chamber to drive the pressure responsive member in a power stroke comprising a pressure dome with a connection for supplying pressure thereto at a predetermined rate, a passage between the dome and pressure chamber, and a part carried by the pressure responsive member and adapted to close the passage with the pressure responsive member in position to commence its power stroke and to be moved therefrom to start the pressure responsive member on its power stroke when the pressure within the dome reaches a predetermined value, the effective area of said part being less than the effective area of the pressure responsive member, means yieldingly urging said pressure responsive member in a direction opposite its power stroke, and a vent for the pressure chamber when the pressure responsive member is at the end of the power stroke.

17. In a motor adapted for actuating a pump or the like, a housing, a pressure responsive member in the housing, said member providing interiorly of the housing a variable capacity pressure compartment, means including a vent, said means actuated by movement of said pressure responsive member to vent said pressure compartment at the limit of the power stroke, a means yieldingly urging the pressure responsive member in a direction opposed to the power stroke, means for pressurizing the compartment at a predetermined rate, and a plunger connected to the pressure responsive member for reciprocation therewith and extending along the longitudinal axis of the housing and exteriorly of the housing.

ARTHUR E. MCFARLAND.

CES CITED The following references are of record in the file of this patent:

UNITED. STATES PATENTS Number Name Date 354,014 Easton Dec. '7, 1886 563,612 Omick July 7, 1896 922,530 Shoemaker May 25, 1909 1,325,657 Robinson Dec. 23, 1919 2,057,364 Bystricky Oct. 13, 1936 2,253,112 Boysson Aug. 19, 1941 2,343,316' Newkirk Mar. 7, 1944 2,396,778 Flowers Mar. 19, 1946