US1925348A - Pumper - Google Patents

Description

E. TIMBS Sept. 5, 1933.

PUMPER Filed Nov, 14, 1928 2 Sheets-Sheet l gwumlo o Sept. 5, 1933. E. TIMBS 1,925,348

PUMP-ER Filed Nov. 14, 1928 ZSheets-Sheet 2 Patented Sept. 5, 1933 UNE'EED STATES PATENT OFF-ICE PUMPER Application November 14, 1928 Serial No. 319,346

1 Claim.

This invention relates to pump operating mechanisms of the type employed in pumping wells, and it is of especial value in the pumping of deep wells such as are found in-some oil fields,

5 though it is to be understood that it is useful in pumping any well in which a string of sucker rods is employed for connecting the pump operating mechanism at the top of the well with the pump in the lower portion of the well.

A very important object of the invention is to increase the efliciency of the pumping mechanism and of the pump.

Another important object is to smooth out the ends of the stroke so as to eliminate the whip ping of the sucker rods that occurs with the usually employed crank motion.

Other objects are low cost ofv maintenance and of the power employed in operating the pump operating mechanism.

Another object is long-continued operation without the necessity of closing down the well for repairs.

Another object is to increase the life of the sucker rods and pump tubing.

Another object is ease of installation.

Another object is to make provision for quickly moving the pump operating mechanism out of the way when it becomes necessary to pull the pump for repairs thereto. The mechanism commonly employed in the oil fields for operating the sucker rods comprises a lever, generally in the form of a walking-beam, a

crank-shaft driven by a prime mover and a pitman that connects the crank with one end of the walking-beam, the other end of the walking-beam being connected by some form of beam hanger with the polish-rod or" the pump. In the operation of this old form of mechanism, the reversal of the stroke occurs relatively sudden, thus producing Whipping of thesucker rods against the pump tubing. This entails wear of the sucker rods and of the pump tubing and oftentimes parting of the rods. When the rods part, the well must be shut down While an expensive fishing job is undertaken. With this old type of mechanism, the up and down strokes occupy approximately the same intervals of time, and one of the important objects of this invention is to provide for an upstroke that occupies a longer interval of time than the downstroke. Thus, the pumping speed is maintained by allowing a quick return of the polish-rod to compensate for the greater length of time occupied by the pump discharging stroke.

Other objects and advantages will appear in the subjoined detail description.

The accompanying drawings illustrate the invention.

Figure 1 is a side elevation of a 'pumper constructed in accordance with the provisions of this invention, fragments of well-casing, pump tubing and polish rod being indicated in broken lines.

Figure 2 is an enlarged plan view of Figure 1.

Figure 3 is an enlarged view, similar to Figure 1, omitting the lower portion of the supporting frame and omitting the Well-casing and pump tubing; 1

Figure 4 is an elevation of Figure 3 from the left thereof, some of the parts being shown in section.

Figure 5 is an enlarged detail illustrating the rollers and the mechanism for moving them in and out of position for use.

Referring to the drawings, a well-casing is indicated at A, a pump tubing, projecting above said casing, at-B, a pipe-line 0 connected with the pump tubing to carry off the Well fluids, a polish-rod at D projecting above the upper end of the tubing through a stuffing box E, and a grip F on the polish rod. The above mentioned elements {are those commonly employed in the pumping of oil Wells and are not a part of the present invention, being merely illustrated, in 35 connection with the invention, so as to make clear the construction and operation of said'invention.

The lower end of the grip F, in the ordinary practice of pumping oil wells, is engaged by a member which is connected by rods or cables and a beam hanger with the walking-beam for actuation of the polish-rod, the point of suspension from the walking-beam being approximately in alignment with the axis of the polish-rod. How ever, during some portions of the stroke of the polish-rod, the rod is thrust laterally to some extent, thus producing wear on the polish-rod and the stufiing-box and tending to throw the sucker rods laterally into contact with the pump tubing, near the upper end of said tubing. .In the present instance, the grip F is supported by a crosshead 11 and, during the greater part of the stroke of the polish rod, the opposite ends of the cross-head are pulled in opposite directions by pitmen or connecting rods 12 which are pivoted at 13 in the opposite ends of said cross-head. The rods 12 extend upwardly and are pivoted at 14, at their upper ends, to cranks 15, respectively, said cranks constituting the cranks of crankshafts 16. The shafts 16 are rotatably mounted in bearings 1'? on the upper faces of horizontal beams 18 that constitute portions of a frame, in dicated in general by the character 19.

The shafts 16 may be spaced any suitable distance apart and, also, the cranks 15, rods 12 and cross-head 11 may be of any desired length. However, to secure the advantages of the invention, the distance between the axes of the pivots 13 is different than the distance center. to center of the shafts 16. In the particular instance illustrated, the shaft centers are spaced a greater distance than the pivots 13. Thus, during the greater portion of the stroke of the rods 12, they will extend at an angle to the vertical, in this instance upwardly and outwardly away from one another. The distance between the pivots of the crosshead is greater than the dis tance between the pivots of the cranks when said cranks project horizontally toward each other. The construction illustrated entails that, when the cross-head 11 is at the very top of its s :oke, the pivots or crank-pins 14 will be positioned outwardly, at H, of vertical planes passing through the axes of the shafts 16 and that, when the cross-head is at the very bottom of its stroke, said pivots 14 will be positioned inwardly, at J, of said vertical planes. If it be assumed that the cranks are rotating in the directions indicated by the arrows adjacent thereto in Figure 3, that is to say, the crank on the left counterclockwise and the crank on the right clockwise, the down stroke of the cross-head will correspond to movement of the pivots 14 through less than 180 of circular measurement and the upstroke of the cross-head will correspond to movement of the pivots 14 through more than 183 of circular measurement. Assuming that the cranks 15 are driven at approximately con stant speed, throughout their rotative cycle, it will now appear that the upstroke of the crosshead and, consequently, of the polish-rod the parts attached thereto, occurs over a greater interval of time than the down-stroke of said cross-head, thus attaining one of the very important advantages of the invention, since the expenditure of power for operating the mechanism is more uniform when the up, or loaded, stroke of the polish-rod is relatively slow and the down, or unloaded, stroke of said polish-rod is relatively quick.

It will be seen that the crank-pins 14 as they move in the last half of their downstroke entail that the rods 12 have relatively great angular motion. This is highly desirable for, when the cross-head approaches the lower end of the stroke, the relatively great angular motion of the rods causes a very gradual deceleration and acceleration of the cross-head, to thereby effect change of direction from downstroke to upstroke without shock or vibration. Shock and vibration are further eliminated by attaching counter-balances 20 to the shafts 16. The angle at which the counter-balances 20 are attached to the shafts in relation to the cranks 15 is such that they reach the highest point in their rotation at approxiniately the moment that the crank-pins 14 are at the points J, or, in other words, at the moment of reversal of the stroke of the cross-head 11 from downward motion to upward motion, this being the time when the load is being picked up. Accordingly, the combination of the relatively great angular motion mentioned above and the counter-balances produces a very smooth and I uniform action.

The counterweights 20 are positioned on the spaced shafts 16 in axially cifset relation in order to obtain the maximum radial sweep for each of the weights. The weight 26 on the righthand shaft 16 is designed to clear the left-hand shaft 16 and thereby obtain a maximum amount of counterbalancing effect for a given mass.

Power may be applied to the shafts 16 in any suitable manner and, of course, it is essential that this be accomplished in a manner to coordinate or synchronize the two crank movements so that the pull on the opposite ends of the cross-head 11 will at all times be exactly the same, thus to keep the polish-rod axially aligned with the stuffingbox.

For the purpose of driving shafts 16 there is provided, in this instance, a pair of meshing spur-gears 21, one on each shaft, and in mesh with one of these is a drive pinion 22 on shaft 23 which rotates in bearings 24 carried by a gearcase 25 that is fixed to the frame 19. Within the gear-case and on the shaft 23 is a wormgear 26 that is operated by a worm-shaft 2'? rotating in bearings 28 that are carried the gearcase 25. The shaft 27 is driven by a prime mover 29 which, in this instance, is in the form of an electric moton The pumper, constructed as above described, is well adapted to be electrically driven, for the reason that the power requirements throughout the cycle are relatively uniform, thus making no extreme demands upon the motor at any particular portion of the cycle. 1?. torque arm 39 connects the gear-case 25, at one point, to the frame 19.

Secured at suitable points to the frame 19 inciosing the gears 21 and 22 is a gear-casev 31. The two gear-cases thus protect all of the. gears from desert sand other dirt, and said earcases hold the lubricating oil so that the ge quietly in the oil at all times, thus wear and noise. I

The lower portion of the frame 19 is in the form of legs or 31. each of them is provided at its lower with a roller 33, the rollers adapted to run in pairs on rails 34. The lower ends of the legs 32 are connected in pairs by horizontal members 35 and these members may be brought to rest upon the rails 34by'lowering said members relative to the rollers 33, and this is accomplished as follows: Each roller 33 is rotatably mounted at 36 on av lever 3'7 which is pivoted at 38 to one of the members 35, there being a lever 3'! and roller 33 on each end of each of the members 35. The end of the lever 3'7 opposite to that provided with-the rollerisi pro vided with a screw 39 that is threaded through the lever and that has its point engaging the bottom plate .40 of the member 35. Thus, by turning the screw 39 in the appropriate directions, the plate 40 may be lowered into engagement with the rail or raised from engagement therewith. When the pumper is inuse, the rollers will be retracted so that the members 35 will rest on the rails. When, however, it becomes necessary to pull the pump or make any other repairs in the well, the rollers 33 will be moved into position to engage the rails and then the pumper will be rolled away from the well a suflicient distance to permit of its the various operations being performed for making the repairs.

The foregoing will nake clear the construction and operation of the invention and, briefly stated, the operation is as follows: 7

Assuming that the pumper is connected up with the polish-rod in the manner shown in the drawings and hereinbefore described, the prime mover will be operated so as to turn the gears 21 in the direction of the arrows indicated thereon in Figure 3. Assuming, at the start, that the parts are in the positions shown in Figure 3, the crankpins 1% will move to the positions H so as to elevate the cross-head 11 to its maximum height.

Continued rotation of the gears 21 causes the rods 12 to descend, first greatly increasing the angularity of said rods with respect to the vertical and then, near the lower end of the stroke, gradually decreasing the angularity of said rods. Owing to the great angularity of the rod motion, the cross-head 11 does not attain too high a speed on its downstroke and, also, the speed of the cross-head as it changes its direction from downward motion to upward motion is comparatively slow, thus picking up the load very smoothly and easily. At this point the counterbalances 20, which have been elevated to their highest points, become effective to assist the prime mover in raising the load imposed on the polish-rod. Continued rotation of the gears 21 then causes the rods 12 to operate on their upstroke and, it is to be noted, their mean angular motion on the upstroke is considerably less than their mean angular motion on the downstroke, thus applying the lifting power of the rods 12 to great advantage. Though that portion of the cycle of the rods 12 that corresponds to the upstroke of the cross-head occurs with the rods 12 at less mean angle than during the downstroke of the cross-head, the length of arc over which the crank-pin 14 passes is greater than on the downstroke of the cross-head, thus tending to slow up the upstroke of the cross-head.

It is to be noted that the connecting rods 12 incline outwardly from the vertical center line of the cross-head for nearly the entire revolution of the cranks, thus exerting a tension equally from both sides of the cross-head. This tension, together with the weight of the sucker rods and the load on the pump, functions in the same manner as a cross-head guide to maintain the crosshead and polish-rod centrally with respect to the stuffing-box, thus eliminating all side thrust upon and wear of the packing and polish-rod. The comparatively small portion of the crank revolution at which the rods incline inwardly and upwardly occurs during the time of upstroke, at which time there are no resulting evil effects.

In the particular instance illustrated in the drawings, the upstroke occupies 197 or 55 percent of the crank revolution, and the downstroke occupies 163 or 45 percent of the crank revolution.

It will be clear from the foregoing that the relative positions of the crank centers and crosshead pivots may be other than illustrated in the drawings and that the only requirement regarch. ing them is that the distance center to center of the shafts must be different than the distance center to center of the cross-head pivots, and that the rotation of the cranks be in the directions to cause the crank-pins to move through a shorter are on their down strokes than on their up strokes.

I claim:

In a pumper, the combination of a frame, a pair of spaced shafts journaled on the frame, a pair of meshing gears mounted on the shafts, means for driving one of the pair of meshing gears, a crank secured to each of the spaced shafts, a pump rod positioned intermediate the cured to said shaft in axially offset relation,

whereby the counter-balancing weights clear each other.

EDWARD TIMBS.

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