US2103742A - Motor apparatus for pumping and other purposes - Google Patents

Description

Dec. 28, 1937. R. H. CARR MOTOR APPARATUS FOR PUMPING AND OTHER PURPOSES Filed June 50, l932 2 Sheets-Sheet 1 R. H. CARR Dec. 28, 1937.

MOTOR APPARATUS FOR PUMPING AND OTHER PURPOSES Filed June 30, 1932' 2 Sheets-Sheet 2 Patented Dec. 28, 1937 UNITED STATES PATENT OFFICE of Ohio Application June 30,1932, Serial No. 620,118

Claims.

pumping cylinder into which an elastic pumping fluid is admitted under pressure, the admittance and exhaust of the fluid being controlledby an automatic valve mechanism whereby upon the admission of fluid into the cylinder, the said piston will be elevated, effecting the operation of a submerged well pump and the elevation of a column of liquid from the well bore, and upon the opening of the exhaust valve and the closing of the inlet valve, the said piston will descend in a. regulated manner, under'the weight of the load suspended therefrom.

In accordance with the present invention, I have provided means which may be applied to well pumping systems of this type and result in reducing the consumption of air or other elastic working fluid used in the operation of the system by effectively expanding the same.

It is another object of the invention to provide an improved link motion between the piston rod of the well pumping piston and the sucker rod line leading to the submerged well pump, whereby through the provision of said link motion, a mechanism is provided permitting of the lifting of the sucker rod and associated column of liquid with less gas pressure under the working piston at the upper part of its stroke than it will on the lower part of the stroke, the operation thus giving the piston in the motor cylinder a mechanical advantage by which the gas or other elastic fluid employed to operate the motor cylinder may be used expansively.

With these and other objects in view, which will appear as the description proceeds, the invention consists in the novel features of construction, combination of elements and arrangements of parts hereinafter fully described and pointed out in'the appended claims. r In-the accompanying drawings: Fig. i is a view in side elevation and partly in vertical section of well pumping apparatus'constructed in' accordance with the present invention; Fig. 2 is a similar detailed view disclosing the positions of the link members when the piston is near the end of its up stroke; Fig. 3 is a vertical transverse sectional view on the line 3-3 of Fig. 1; Fig. 4 is a horizontal sectional view taken on the plane disclosed by the line 44 of Fig. 3; Fig.5 is a similar view on the line 5-5 of Fig. 3.

Referring more particularly to the drawings when my improved motor apparatus is used for pumping oil wells, the numeral l designates the head portion of the casing of an oil well or other well of any suitable depth. Arranged in the bot- 10 tom of this casing in the liquid producing region of the well is a submerged pump mechanism (not shown) which is operated to effect the lifting of the liquid from the well by a string of pump rods 2. The latter extend above the casing, and in 15 this instance, are connected for vertical movement with a reclprocatory piston. 3, the latter being mounted for sliding movement in a. motor cylinder 4, suitably supported above the well bore but in vertical registration therewith.

In order to operate the piston 3 whereby to reciprocate the pump rods 2, use is made of a comv pressor 5 which delivers an elastic working fluid under pressure to a container 6. leading from the container 6 is a pressure line 'i which enters the 25 bottom of the cylinder 4 subject to the regulation of inlet valve means. When the piston is at the bottom of the cylinder 4, the inlet valve means may be opened automatically to admit air, gas

or other elastic fluid'into the cylinder 4 to effect 30 (not shown) for holding desired back pressure on 40 the exhaust. The inlet and outlet valve means .may be of any suitable character and for the purposes of the present invention, the said valvemeans are shown as provided with cranks 8 which 3 are engageable with adjustable stops 9 provided 45"- on the piston rod Ill which is rigidly connected with the piston 3 and extends through a stuffing box in the bottom of the cylinder 4. Theopening and closing, therefore, of the valvemeans will be automatically effected. 50

To permit of the direct discharge of the elastic working fluid to the atmosphere through the vent ll, provision must be made for sustaining the load of the submerged pump and the column of liquid above the sameduring. the descent of 55 the piston 3. To permit of this, there is arranged above the cylinder 4, a counterbalancing cylinder |2 in which is mounted for reciprocation a piston l3, which is directly connected with the piston 3 in the cylinder 4 by a rigid piston rod I 4, the latter passing through stufling boxes provided in the upper head of the cylinder 4 and the lower head of the cylinder l2. The piston in the counterbalancing cylinder ordinarily possesses a smaller effective area than the piston in the motor cylinder 4, and the high pressure line I is provided with a branch l5 which leads directly to the lower part of the counterbalancing cylinder. Thus the area of the piston l3 and the pressures employed thereon are so balanced with relation to the load suspended from the pistons 3 and I3 that the piston l3 will serve to provide for a regulated and controlled descent of the pumping mechanism even though the exhaust valve means of the cylinder 4 opens direct to the atmosphere, or at relatively low back pressure.

The upper ends of the cylinders 4 and I2 are provided with valved by-passes I 6, whereby in the event of sudden release of load on said pistons, while the latter are advancing on their up strokes, a pneumatic cushioning or shock absorbing means will be provided in the upper end of each cylinder to arrest the shock of the reaction and prevent injury to the apparatus. The bypass connection I6 is such that if the pistons 3 and I3 uncover the lower ends of the same, the elastic working fluid will travel through said connections and to the upper end of each cylinder, producing the aforesaid cushioning action. The upper end of the cylinder l2 may be provided with a clevis I1 by which the cylinder structure as a whole may be suspended from a derrick or other suitable overhead support.

The lower end of the piston or polish rod I0 is pivotally connected as at I8 with a pair of downwardly diverging links I9, and the lower ends of the links l9 are, in turn, pivotally connected as at 20 with a pair of upwardly diverging links 2|, the lower adjoining ends of the links 2| being pivotally connected as at 22 with the upper end of a polish rod 23. The pivotal connections between the adjoining portions of the links l9 and 2| carry rollers 24. which engage with a fixed trackway 25 mounted upon an upstanding support 26. The trackway 25 possesses its greater Width adjacent to its lower portion as at 25a and this width is sustained through a certain part of its height and then gradually decreases as represented by the inwardly curved regions 25!) of the trackway.

It will be noted that at the beginning of the up stroke of the piston 3, the rollers 24 on the toggle arms or links l9 and 2| are in a position so that upward movement over the first part of the stroke will result in the links of the toggle remaining in substantially fixed relative positions, resulting in the movement of the sucker rods in the well and the well pump being prac-'- tically equivalent to that of the piston 3 in themotor cylinder 4. As the stroke progresses upwardly, the rollers conform to the curvature 25b of the trackway, changing the position or length of the toggle so that the piston in the motor cylinder travels a greater distance than the corresponding travel of the submerged well pump, thus giving the piston in the motor cylinder a mechanical advantage which enables the system to use the elastic working fluid in the motor cylinder expansively; thereby performing more work with it.

Work equals force times distance. It is evident that if air under pressure is admitted to the motor cylinder during the initial part of the stroke only and is allowed to expand against the piston, the pressure or force which it exerts will gradually decrease until it is equal to the resistance offered by the string of tools. If no mechanical advantage were imparted to the motor cylinder at this point, movement of the well tools would cease. But, if the distance through which the motor cylinder is permitted to move is increased relative to the distance through which the string of tools moves, the value F D for the motor cylinder will exceed the resistance offered by the string of tools and useful work will be performed.

It is evident from the drawings that during the travel of the rollers 20 from the points 25 on the track to the position shown in Figure 2, the connection 22 and consequently the polish rod 23 will move upwardly. This is due to the fact that the curved sections 25b of the track meet at a higher point than the top of an are having a radius equal to link 2| and having its center at the connection 22 when the rollers 24 are at the points 25. In order for the toggle connection to collapse without moving the polish rod, it is necessary to keep the connection 22 stationary and permit the rollers 24 to move over the circumference of a circle of radius equal to link 2|. But these rollers are compelled-to move to a higher point than any point on such a circumference and their upward movement necessarily pulls the links 2| and polish rod upwardly at a slower rate. Thus by gradually increasing the relative distance of travel between the motor piston and the polish rod, the force of the air pressure is able to do suilicient work to continue to lift the well tools.

It will be understood that mechanism of a considerable variety of design can be used to perform the same result as the toggle links set forth and the right is therefore reserved to employ various mechanical motions for attaining this result.

In summary, therefore, the apparatus disclosed will lift the sucker rods and the column of liquid oil with less pressure under the piston 3 during the upper part of the stroke than it will on the lower part of the stroke. It will be ob served thaton the lower part of the pumping stroke, there is considerable movement at the beginning of the stroke before any change takes place in the relative positioning of the toggle tions 25b of the trackway, I provide track exten-- sions 250 of parallel closely related order. The

from, means for admitting an elastic working fluid under pressure into said cylinder to effect the elevation of said piston and its suspended load, and compensating means between said piston and the suspended load, said compensating means serving to effect substantially uniform linear travel of the piston and its load in the lower part of the up stroke of said piston and increased linear travel of said piston with respect to the suspended load during the upper portion of the up stroke of said piston.

2. Motor apparatus comprising a cylinder, a piston slidably mounted in said cylinder, and having a gravity load suspended therefrom, means for admitting -an elastic working fluid into said cylinder during. the up stroke ofthe piston therein and discharging said fluid from said cylinder during the down stroke of the piston, and a variable length connection between said piston and its suspended load, said connection providing for substantially uniform linear rates of travel of the piston iri said cylinder and the suspended load during a considerable portion of the length ofthe up stroke of said piston and for an increased rate of linear travel of said piston in proportion to that of the suspended load during the upper portion of the up stroke of said piston, whereby to provide forthe expansion of the working fluid in said cylinder.

3. Apparatus of the character described comprising a motor cylinder, a piston mounted for reciprocation in said cylinder, 2. piston rod extending from said piston, a. toggle connection 'uniting the lower end of said piston rod with a gravity load, a guide frame for controlling and changing the effective length of said toggle connection, valve means for admitting a gaseous working fluid under pressure into said cylinder beneath said piston, and means for closing said valve means prior to the end of the up stroke of said piston.

4. Apparatus of the character described com' prising a motor cylinder, a piston slidably mounted in said cylinder, valve means for admitting an elastic working fluid under pressure into said cylinder during the power stroke of said piston,

Y valve 'means operative to discharge fluid from said cylinder during the return stroke of said piston, and a connection, adapted to vary in length during each stroke of the piston, uniting said piston with a gravity load.

' 5. Apparatus of the character described comprisinga motor cylinder, a piston operable in said ,cylinder, automatic fluid inlet and discharge valves associated with said cylinder, and means adapted to vary in length during each stroke-of 3 said piston, connecting said piston to a gravity load.

6. Apparatus of the character described comprising a motor cylinder, a piston operable in said cylinder, fluid inlet and discharge valves associated with said cylinder, means to close said inlet valve prior to the end of the power stroke of said piston and means adapted to vary in length during the time when said inlet valve is closed, connecting said piston with a gravity load.

-7. Apparatus of the character described comprising a motor cylinder, a piston operable in said cylinder, fluid inlet and discharge valves associated with said cylinder, means to close said inlet valve prior to the end of the power stroke of said piston, and means connecting said piston when said inlet valve is closed.

8. Apparatus of the character described comprising a reciprocating means, fluid means operable to drive said reciprocating means, a gravity load adapted to be lifted by said reciprocating means and a means connecting said reciprocating ,means to said load adapted to automaticallyimpart a mechanical advantage to said reciprocating means during the latter part of the lifting stroke thereof only. a

9. Apparatus of the character described comprising a;reciprocating.means, expansible fluid means operable to drive said reciprocating means, v

a gravity load adaptedto be lifted by said reciprocating means, means for reducing the supply of said fluid means to said reciprocating means prior to theend of'its lifting stroke, and .a means connecting said reciprocating means to said load adapted to automatically impart a mechanical advantage to said reciprocating means during the latter part of the lifting stroke thereof only.

10. Apparatus of the character described comprising a motor. cylinder, a piston slidably mountfor'admitting to and discharging an expansion end of the piston stroke, and means for automatically imparting a mechanical advantage to said motor cylinder only during a portion of the stroke when the fluid supply is cut off.

RICHARD H.-CARR,

ed therein, a load connected to said piston, means

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