US2377743A - Electrical deep well reciprocating pump assembly - Google Patents

Description

June 5, 1945. A. ARUTUNOFF T 2,377,743

ELECTRICAL DEEP WELL RECI PRQGATING PUMP ASSEMBLY Filed March 1, 1941 I 4 Sheets-Sheet HTTORNEX June 5, 1945. A. ARUTUNOFF ELECTRICAL DEEP WELL RECIPROCATING PUMP ASSEMBLY 4 Sheets-Sheet 2 Filed March 1, 1941 a w% m Nf T J1me 1945- -A. ARUTUNOFF 2,377,743

ELECTRICAL DEEP WELL RECIPROCATING PUMP ASSEMBLY Filed March 1, 1941 '4 Shets-Sheet s INVENTOR.

, Patented June 5, 1945 ELECTRICAL DEEP WELL BECIPBOCATING PUMP ASSEMBLY Armais Arutunofl, Bartlesvllle, Okla asslgnor to Reda Pump Company, Bartlesvllle, th., a corporatlon of Delaware Application March 1, 1941, Serial No. 381,296

9 Claims. (Cl. 172-239) My invention relates to electrical deep well reciprocating pump assemblies and more particularly to a pump and motor assembly adapted to be lowered to the bottom of a well whereby a reciprocating pump will be driven directly from an electric motor, together with electrical mean for reversing the same to obtain the reciprocating motion.

This application is an improvement over my copending application, Serial No. 328,419, filed April 8,1940.

In many areas, after the gas pressure in a field has been depleted, it is necessary to pump the oil out of the well. At present, there are two types of pumping equipment available. One is known as the Reds. pump which comprises a multistage centrifugal pump and motor assembly. The assembly is adapted to be lowered into the well and to pump the oil out of the well without the necessity of using a long string of sucker rods. The other type of pumping equipment available comprises a reciprocating pump which is actuated through a string of sucker rods operated by any suitable means such as a motor driven walking beam. The pumping of oil with sucker rods has many disadvantages. The cost of the string of rods and the time consumed in placing the rods and removing them when it is necessary to replace valves and the like, is considerable. Sucker rods frequently break, resulting in the shutting down of pumping operations and the necessity of fishing for the broken rod string. The power consumed in reciprocating a long string of rods is so much waste in so far as the removal of oil from the well is concerned.

One object of my invention is to provide a novel motor and reciprocating pump assembly adapted to be lowered into the Well, whereby oil may be pumped from the well. by the reciprocating pump without the necessity of moving a long string of sucker rods.

Another object of my invention is to provide a pumping assembly which may be installed and removed from the well as a unit avoiding the time, labor and expense of handling a plurality of sections of sucker rods.

Another object of my invention is to eliminate wiring by the use of the power supply lines and lines for actuating the reversing mechanism in a single circuit, and utilizing the eduction tubing as a conductor in said circuit.

Another object of my invention is to provide a motor and reciprocating pump assembly having novel means for reciprocating the pumping means.

Other and further objects of my invention will appear from the following description.

In the accompanying drawings which form part of the instant specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views;

Figure l is an elevation of a motor pump assembly showing one embodiment of my invention.

Figure 2 is an enlarged sectional view of a portion of my pump assembly directly beneath the motor housing.

Figure 3 is an enlarged sectional view of a portion of the pump assembly directly below the portion shown in Figure 2.

Figure 4 is an enlarged sectional view of a portion of the pump assembly directly below that portion shown in Figure 3.

Figure 5 is a sectional view on an enlarged scale of the bottom section of my pump assembly.

Figure 6 is a sectional view of a portion of the pump assembly taken in the vicinity of the portion shown in Figure 2 but at right angles thereto and showing the parts at the limit of the upstroke.

Figure 7 is a sectional view taken on the line 'i-l of Figure 2.

Figure 8 is a sectional view taken on the line 3-8 of Figure 2.

Figure ii is a sectional view taken on the line il of Figure 3.

Figure id is a sectional view taken. on the line ill-89 of Figure 3.

Figure 11 is a diagrammatic view showing the electrical circuits involved.

Referring now to the drawings, the assembly is capped with a forging i communicating with eduction tubing it through which the liquid is delivered to the surface. The forging l is provided with serrations 3, adjacent the upper end thereof, adapted to receive suitable lowering clamp and fishing tools. The forging l is connected by a tube 5 to a housing ii in which the electrical motor is positioned. The motor housing 5 is connected to the tube 4 by means of a fitting 6. Power is furnished to the motor through a cable '27. A connector 8 joins the motor assembly to the pump assembly. The connector 8 is bolted to a housing by means of bolts l0, as can readily be seen by reference to Figure 2. The housing 9 contains the thrust bearings II. The motor shaft terminates in the splined end I! which is connected by connector 13 to a shaft I4 which is provided at its lower end with an elongated threaded portion IS. A connecting section I 8 is threaded to a housing I! to which a packing housing I3 is secured. The packing housing I3 supports a connecting fitting I3 to which the pump barrel 23 is secured. A foot valve housing 2| i supported by the pump barrel 23. A nut 22 engages a threaded portion I5 of the acialating shaft through the medium of a plurality of ball bearings 23. The ball bearing nut 221s a tool of the art and it is understood that any suitable form of nut and thread'means may be employed. The screw is of small gauge and in this case I used small balls to allow a high rotation with a slow reciprocating speed of the nut 22. The nut 22 carries an upper skirt 24. The skirt 24 is really an annular piston adapted to enter an annular cylinder 25, formed by tubular member 25 and the walls of the connecting section I 4. The annular cylinder 25, as well as the entire housing is normally filled with oil and acts as a hydraulic brake, as will hereinafter be described more fully. The upper portion of the cylinder is normally closed by a ring 23' provided with a plurality of ports 21, normally closed by check valves 23. The clearance at the entrance 23 of the annular cylinder 25 and the annular piston 24 is normally about two thousandths of an inch'(.002") A tube 33 alongside the pump assembly contains conductors 3i leading to the control circuit. One oi. these conductors makes contact through an opening-normally closed by a plug 32 with a contact whisker 33.

A connecting tube 34 is threadedly secured to the lower portion of the nut 22 and carries at its lower end another annular piston 35. The pump rod 36 is also secured to the member 35 as can readily be seen by reference to Figures 3 and 9. The annular piston 35 is adapted to enter the annular cylinder 31, shown in Figures 3 and 4. The annular piston 35 and-the annular cylinder 31 act as a hydraulic brake for the limit of the downstroke, as will be more fully described. The conductor housing tube 33 contains a control conductor 38, which makes electrical connection with a contact whisker 33 as can readily be seen by reference to Figure 3, through an opening normally closed by a plug '43, I

The lower end of the actuating screw I5 is prevented from moving in a horizontal plane by means of a guide member 4|, housed in a floating centering plate 42. The plate 42 is provided with a plurality of openings 43 to permit the free passage of oil.

the lower end thereof. The member 35 is provided with a plurality of holes 44 to permit the free passage of oil during the reciprocation of the pump rod and nut. Splines 45 and 43 are secured to the interior of housing II, as can readily be seen by reference to Figures 6, '1, 8, 9, and 10, to prevent the nut from turning with the screw. The splines allow reciprocation of the nut and associated parts, while preventing their rotation relative to the housing. The annular cylinder 31 is closed by a ring 41, fitted with a plurality of relief ports 48, normally closed by check valves 43. The annular cylinder 31 is supported from the walls of the housing II by means of a ring 53. The space within the housing I! below the ring 53 forms an annular area 5i in which is positioned a floating piston 52 provided with packing members 53 and a plurality of ports 54 and 55. Ports 54 discharge into the space below the piston while ports 55 discharge into the space above the piston. Check valves 53 seat upwardly, while check valves 53 seat downwardly. The lower side of the floating piston communicates with the fluid It is to be noted that the pump rod 33 is secured to the member 35 centrally of in the well through a port 53. The piston moves to compensate for pressure differentials produced in housing I1 by reciprocation of the pumping and reversing mechanism. A tube 13 forms the inner boundary of the annular space in which the piston moves and houses the pump rod 35. The pump rod 35 passes through a packing section II containing packing I I. A port I2 permits leakage from the pump to be discharged into the well.

The pump rod 35 carries at its lower end the pump piston or plunger I3 operating within the pump barrel 23. The pump is a double acting one. On the upstroke, fluid from the well passes the check valve I4 and flows into the pump barrel beneath the plunger I3. At the same time, fluid above the plunger i lifted, flowing through fltting 15 past check valve I6, through eduction tubing I3. On the downstroke, fluid below the plunger I3 previously taken into the pump barrel, flows outwardly through fitting I3, past check valve 33, through eduction tubing 3|, On the downstroke, fluid from the well passes through intake port 32, past check valve 33 into the pump barrel above the plunger.

In operation, the motor within housing 4 is rotating the actuating screw I5 through the splined shafts I2 and I4 and the connector I3. Let us assume that the screw shaft I5 is turning in a direction to move the nut 22 upwardly. The upward motion of the nut 22 carries the connecting tube 34, the member 35 and the pump rod 35 upwardly, thus carrying the plunger 13 upwardly and lifting oil above the plunger upwardly and out through the connection I5 and eduction tubing 13, thence into the hollow forging I and out of the eduction tubing 2 to the surface. In the position shown in Figure 2, it will be noted that the whisker 33 which passes through plug 32 in an insulating bushing 34 (as can be seen by reference to Figure 7) has made contact with the annular piston 24.

Referring now to Figure 11 where I have shown a diagrammatic view of the electrical circuits involved, the three conductors 33, 3|, and 32 are the three supply lines of the three-phase alternating current. The field winding for the induction motor which may have a squirrel cage rotor, is shown diagrammatically by the three branches 33, 34, and 35. The winding produces a rotating field which is followed by the squirrel cage rotor of the motor. In the position of parts shown in Figure 11, line 33 is connected to windmg 34 throughconductor 36 and contact point 31, \contact point 33, contact point III, contact point I I2, conductor 33 and conductor I33. Similarly, main line wire'ili is connected to winding 33 of the field through conductor I3I, contact point I32, contact point I33, contact point I44, contact point I35, conductor I 36, conductor I31, the winding I33 oi the overload relay, and conductor I33. The main line wire 32 is directly connected to winding 35 through conductor Ill. With the three branches of the Y-connected field winding, a rotating field, rotating in one direction, will be produced. Contact points 33, III, I33 and I34 are held in contact with contact points 31, H2, I32 and I35 respectively by the armature I I 3, due to the energization of the winding II4 by current flowing from main line wire 33 through conductor H5, conductor H5, conductor I I1, through winding II4, through conductor II3, through conductor II3, through contact point I23, through conducting member I, through conductor I22, thence to main line conductor 32, thus completing a circuit between main line wires 33 and 32.

Contacting of contact point I with conducting member I2I also completes the circuit from main line wire 33 through conductor II3, through conductor II3, through conductor I 23, through conductor I23, through winding I21 of the time delay relay, thence through conductor I23 to conductor II3 to contact point I20 to conducting member I2I to conductor I22, to main line wire 32. The energization of winding I2'I ejects armature I23, completing the circuit between contact points I30 and I32, thus conditioning the circuit for the reversing action which will be hereinafter described.

It will be observed that the reversing switch comprises a pivoted arm I33 connected at its ends to armatures H3 and I34. Armature I34 is pushed upwardly when the winding I33 is ener-' gized.

when the whisker 33 contacts with the annular piston 24, current will flow from main line wire 32 through conductor IIII, through conductor I33, through conductor 3| and thence to piston 24 through whisker 33. This circuit from main line wire 32 through whisker 33 to piston 24 is completed through the metal parts of the pumping mechanism and eductlon tubing 2 diagrammatically shown in Figure 11 as a conductor I33. .(This circuit may or may not be grounded as shown at I33.) From the eductlon tubing 2 the circuit is completed through conductor I43, through contact point I32, through conducting member I, through contact point I30, through,

conductor I42, through the winding I24, through conductor I43, through conductor II5, to the main line wire 33. The energization of winding I24 will attract the armature I23, pivoting the arm I44 so that the conducting member I2I will make contact with contact point I43. When this occurs, the coil II4 will be deenergized, while the coil I33 will be energized by current flowing from main line wire 33 through conductor I I3, through conductor IIG, through conductor I", through winding I33, through conductor I43, through conductor I41, through contact point I43, through conducting member I2I, through conducting member I22 to the other main line wire 32. The energization of winding I33 will move armature I34 upwardly. When this occurs, main line wire 33, theretofore connected to winding 34, will be annular piston 24 upwardly a considerable distance before the direction of rotation is changed. The whisker 33, therefore, will remain grounded for a considerable period or time.

It will be noted, further, that when the circuit is broken between contact point I20 and the conducting member I2I, that the coil I21 will be deenergized, thus permitting armature I23 to break the circuit between contact points I33 and I32, thus deenergizing coil I24. The switching action, however, has already taken place by this time and the latching relay is such that the conduct ing member I2| will be held in contact with contact point I43. Besides energizing th winding I33, the latching relay also completes the circuit from line wire 30 through conductor II3, through conductor II3, through conductor I23, through conductor I33, through winding I30, through conductor I3I, through conductor I41, through contact point I43, through conducting member I2I, through conductor I22, back to the other side of the line 32. The energizaticn of winding I30 will raise armature I32. The raising of armature I32, however, is delayed by any suitable means to introduce a time delay as is well known in the time delay relay art. This delays the completion of the circuit between-contact points I33 and I34 by the conducting strip I33 a sufllcient length of time to enable the screw I3 to move the nut 22 downwardly a suflicient distance so that the whisker 33' is out of contact with the annular skirt of piston 24; After the circuit has been broken by the downward movement of the nut, a circuit is completed through contact points I33 and I34 so that, when whisker 33 contacts the annular piston 33 at the bottom of the stroke, current will flow fom main line wire 32 through conductor IIII, through conductor I33, through conductor I33, through whisker 33, piston 35,

through metal parts-of pumping mechanism conconnected to winding 33 through conductor I43, I

contact point I43, connecting strip I50, contact point I 3i, conductor I3'I, winding I03, and conductor I03. Similarly, main line wire 3I which had been connected to winding 33, will be disconnected from winding 33 and connected to winding 34 through conductor I52, contact point I33, conducting strip I34, contact point I53, conductor I33, and conductor I33. The reversal of the main line connections to coils 33 and 34 will reverse the direction of rotation of the rotating held of the induction motor, thus producing a reversal in the direction of the driving screw I3. The latching relay is of the type which takes positive energization of one of its actuating coils to operate it. In other words, It will remain in the position shown in the drawings until coil I23 is energized in the manner just described. It was moved to the position shown in the drawings by a previous energization of coil I31 acting through armature I53 and the pivoted arm I44.

It takes an appreciable interval of time for the rotating held to have effect, and ordinarily the inertia of the rotor is such that it will move the thence through conductor I43 and conductor II5 to the other side of the line 30. It will be seen that the whisker contacts alternately, grounding at the top and bottom of each stroke effects a reversal of the direction of rotation of the actuating screw 83.

If for any reason, due to the insulating action of the oil or disarrangement of the whisker contacts, a reversal should not .take place, I have provided another means'of reversing. It will be observed that the annular skirt 23 is a piston having small clearance with the annular cylinder 23. In the position of the parts shown in Figure 6, the annular piston 24 is shown a considerable distance within the annular cylinder 23. Oil in the cylinder 23 is displaced by the piston downwardly through the small clearance at the mouth of the annular cylinder. It will be seen that we have a species of hydraulic brake. The increased load introduced to the motor by the braking action, that is, by the work expended in'forcing oil past the small clearance between the annular piston and the cylinder mouth, produces a temporary overload so that there is a surge of current through the winding I03 of the overload relay. .When this occurs, the armature III is raised, carrying with it conducting strip II2, completing the circuit across contact points "3 and II4.- When this occurs, a circuit. is completed through one or the other of winding I21 or I3I, depending on whether armature I23 is raised or armature I82 is raised. In the position of parts shown in Figure 11, when the circuit is completed across contact points I13 and I'll, current will flow from main line 92 through conductor I22, through conductor I", through contact point Ill, through conducting strip I12, through contact point "3, through conductor I16, through conductor Ill, through contact point I32, through conducting strip I, through contact point I30, through conductor I42, thence through winding I, conductor I43, conductor H5, to the other side of the line 8|. This energizes the winding I24 attracting the armature I23 and causing a reversal in the same manner as heretofore described.

It will be seen that I have provided two independent means of initiating the reversal of the motor. Normally, I prefer to use the contact whiskers since the surges of current throughthe windings produced by temporary overloads tend to overheat the stator, which is not desirable in a deep well pump. The surges, however, are only momentary and I provide an eil'ective safety means for insuring a reversal of the motor in event the whisker contacts are not effective, through unforeseen circumstances.

It will be seen that I have accomplished the objects of my invention. I have provided a simple deep well pump of a reciprocating type and thus avoid the necessity of using long strings of sucker rods, thus saving time, labor, and expense. My construction is an improvement over the mechanical reversing means shown in my copending application, Serial No. 328,419, in that no mechanical parts are required at the bottom of the well. The relays for reversing the direction of rotation may be located on the surface and thus may be serviced from time to time without the necessity of pulling the pump. The whisker relays may be so designed that they will operate for long periods of time. The arrangement for producing artificial overloads at the top and bottom of the stroke insures, however, the reversal of direction of rotation of the motor, irrespective of whether the whisker relays become disarranged Or not.

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 my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is. therefore, to be understood that my invention is not to be limited to the specific details shown and described.

Having thus described my invention, I claim: 1. A reciprocating drive mechanism including in combination a housing, an alternating cur rent motor in said housing, a screw adapted to be driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation of said nut, reversing means for said motor, an actuating means for operating said reversing means, said actuating means including an annular cylinder within said housing adjacent the upper limit of the travel of said nut, an annular cylinder within said housing adjacent the lower limit of the travel of said nut, an annular piston carried by said nut thereabove, an annular piston supported by said nut therebelow, said upper annular piston adapted to enter said upper annular cylinder and create an overload on said motor thereby, said lower annular piston adapted to enter said lower annular cylinder and create an overload on said motor thereby. and an overload relay responsive to the respective overloads created at the upper and lower limits of the travel of said nut for initiating the action of said reversing means.

2. A reciprocating drive mechanism including in combination a housing, an alternating current motor in said housing, a screw adapted to be driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation of said nut, said motor comprising a three-phase induction motor having a rotating magnetic field, reversing means for said motor including a reversing switch ior reversing the connections of two or said field windings with respect to each other whereby the direction oi rotation of said magnetic field is reversed, a latching relay for operating said reversing switch, a time delay relay for operating said latching relay, and means responsive to the movement of said nut for operating said time delay relay.

3. A reciprocating drive mechanism including in combination a housing, an alternating current motor in said housing, a screw adapted to be driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation of said nut, said motor comprising a three-phase induction motor having a rotating magnetic field, reversing means for said motor including a reversing switch for reversing the connections of two of said field windings with respect to each other whereby the direction of rotation of said mag-- 0 means within said housing for creating an overload at the upper and lower limits of the reciproeating motion of said nut whereby to actuate said overload relay, and means responsive to the actuation 01 said overload relay for initiating the operation of said time delay relays to operate said latching relay to energize said reversing switch to reverse the direction of rotation of said motor.

4, A reciprocating drive mechanism including in combination a housing, an alternating current motor in said housing, a screw adapted to be driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation of said nut, said motor comprising a three-phase induction motor having a rotating magnetic field, rovers ing means for said motor including a reversing switch for reversing the connections of two 0! said field windings with respect to each other whereby the direction of rotation of said magnetic field is reversed, a latching relay for oper-- ating said reversing switch, a time delay relay for operating said latching relay, an electrical contact within said housing adjacent the upper limit of motion of said nut, a contact point within said housing adjacent the lower limit of travel of said nut, means carried by said nut for grounding said contact points adjacent the upper and lower limits of travel of said nut, and means responsive to the grounding of said contact points driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation of said nut, said motor comprising a three-phase induction motor having a rotating magnetic field, re-

versing means for said motor including a reversing switchv for reversing the connections of two of said field windings with respect to each other whereby the direction of rotation of said magnetic field is reversed, a latchingrelay for operating said reversing switch, a time delay relay for operating said latching relay, an electrical contact within said housing adjacent the upper limit of motion of said nut, a contact point within said housing adjacent the lower limit or travel of said nut, means carried by said nut for grounding said contact points adjacent the upper and lower limits of travel of said nut, means responsive to the grounding of said contact points for energizing said time delay. relay to operate said latching relay to operate said reversing switch to reverse the direction of rotation of said motor, and a hydraulic braking means within said housing adjacent the upper and lower limits of travel of said nut. v

6. A reciprocating drive mechanism as in claim in which said hydraulic braking means comprises an upper annular cylinder adapted to contain oil, a lower annular cylinder adapted to con- ,tain oil, respective upper and lower annular pistons carried by said nut, said pistons adapted to in said housing, a screw adapted to be driven by said motor, a nut threadedly mounted on said screw, coacting means on said housing and said nut for preventing rotation 01' said nut, reversing means for said motor including a reversing switch, electromagnetic means for operating said reversing switch, a latching relay for operating said electromagnetic means, a relay for operating said latching relay, an overload relay for operatin said last named relay, braking means within said housing for braking, the travel of said nut adjacent its upper and lower limit of motion, said braking means adapted tocreate a motor overload at the upper and lower limits of travel of said nut, whereby to operate said overload relay to initiate the reversing of direction of rotation of said motor.

8. A reciprocating drive mechanism comprising a housing, an induction motor within the housing, reversing means for the motor, an electrical circuit for supplying current to the motor, a reciprocal means driven by said motor, means co-active with said reciprocal means at the ends of its stroke to overload said circuit, and means responsive-to the respective overloads for actuating the said reversing means.

9. A reciprocating drive mechanism comprising a housing, an induction motor within the housactive with said reciprocal means at the ends of its stroke to overload said circuit, and an over-' load relayior actuating the said reversing means.

' ARMAIS ARUTUNOFF.

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