US2045945A - Fluid motor - Google Patents

Description

June 30, 1936.

R. H. CARR FLUID MOTOR 4 Filed June 25, 1932 Patented June 30, 1936 UNITED ASTATES PATENT oFFlcl-z Pure Oil Company, of Ohio Chicago, Ill., a corporation.v

Application June 23, 1932, Serial No. 618,926

'l Claims. (Cl. 121-118) This invention relates to an improvedpumping mechanism of the iiuid operated type which has been especially designed for use in the pumping of oil Wells, and it is an object of the invention to provide a pumping mechanism comprising a motor cylinder structure having arranged therein a sliding piston having directly suspended therefrom pump rods which lead downwardly through the well bore to a submerged pump, provision being made for regulating the admission and expulsion of the gaseous working duid into s the cylinder structure for controlling the reciprocation of the piston and the removal of liquids from the associated well. In the operation of motor cylinders of this type, the-gaseousv working iiuid is admitted into the cylinder structure under pressure and below the piston to effect the elevation of the piston and its suspended load. Upon the completion of the up stroke of the piston, further admittance of the working uid into the cylinder is arrested by the closing of the duid inlet valve mechanism. At this point, the exhaust valve mechanism is opened which permits the piston to descend at a controlled rate in response to the weight of the load suspended therefrom, such rate of descent being governed by the regulated escape oi the working duid from the motor cylinder through the exhaust valve mechanism. In my prior Patent 1,860,137 issued May 24, 1932, I have set forth a pumping system of this type wherein the exhaust iluid of the motor cylinder is returned under pressure to the inlet side of a power driven compressor, to provide for cyclic use of the working fluid.

In accordance with the present invention, in order to reduce equipment costs and to provide tor a structurally simplied well pumping system of the duid type, the working fluid exhaust from the motor cylinder is discharged directly into the atmosphere and is not recycled to the compressor so that installation economies are obtainable. However, since the working uid is discharged directly into the atmosphere upon the down or exhaust stroke of the piston, it is necessary to employ supplemental means for counterbalancing the weight of the mechanism suspended from the piston upon the down stroke of said piston, and therefore, it is an outstanding feature ci the present invention to provide a counter-balancing cylinder located above and in axial alignment with the motor cylinder, the said counter-balancing cylinder being of einer dlameter than the motor cylinder and is provided with a piston directly connected through e rod ".5 with the piston in e motor cylinder so :we

both of said pistons move in their respective cylinders in unison.k However, in the case of the counter-balancing cylinder, a constant pressure is maintained on the under side of the piston at all times, during both up and down strokes, and the 5 effectivel area of the piston in the counterbalancing cylinder and the pressures applied thereto are such as to provide for the controlled descent of the mechanism suspended from the piston of the pumping cylinder, permitting the 10 working fluid used in the motor cylinder to be exhausted directly into the atmosphere and yet providing at all timesfor a controlled and uniform rate of travel ofthe pumping mechanism on both up and down strokes.

It is another object of the invention to provide both the motor and counter-balancing cylinders with pneumatic cushioning means in the upper regions thereof, whereby in the event of the sudden release of load on said pistons due, for in- 20 stance to the parting of sucker rods, unduly accelerated upward movement of said pistons will be cushioned or absorbed to avoid injury to the cylinder structure as a whole. y

The nature of my invention in one of its specic 25 embodiments will be more fully understood by reference to the following description and the accompanying drawing, wherein:

Fig. 1 is` a diagraatic view, partly in vertlcal section, disclosing my improved well pumping 30 mechanism;

Fig. 2 is an enlarged vertical-sectional view disclosing the adjoining ends of the motor and counter-balancing cylinders;

Fig. 3 is a similar view through the lower end 35 oi the motor cylinder.

Referring more particularly to the drawing. the numeral l designates my improved pumping mechanism in its entirety. This pumping mechanism comprises a cylinder structure consisting 40 of a motor cylinder 2 and a counter-balancing cylinder 3, the said cylinders being rigidly connected in longitudinally aligned order with the counter-balancing cylinder 3, in th instance, being ydisposed. above and in axial rseltration 45 with the motor cylinder 2. The upper end of the counter-balancing cylinder is provided with a head il by which the entire cylinder mechanism is suspended from a derriclx or other support (not shown) in order that said cylinder structure 50 may be disposed above the casing t of a well' here. It'will be understood that in the bottom oi said casing or well bore there is usually arranged a submerged pump (not shown) which is to he operated by the pumping" mec v of the present invention to expel liquid from the producing region of the bore. In order to operate this submerged pump, use is made of a'string of sucker rods 6 which extend through the bore and have their upper ends connected with a polish rod l. In this instance, the polish rod is connected with a piston rod 8 connected with a piston 9 slidably mounted in the motor cylinder 2, the rod 8 extending through a packed bearing I0 provided in the closed lower end Il of the motor cylinder. By this construction, it will be seenthat as the piston 9 is reciprocated, the submerged pump in the bottom of the well will be operated to force liquid upwardly and out of the well bore.

To govern the operation of the piston 9, use is made of a compressor I2 by which an elastic working duid isA placed under suitable pressure and delivered to a tank I3 from which it may be withdrawn by a pipe line I l leading to the admission valve I5 in the bottom oi' the motor cylinder 2. When the admission valve is open, the elastic working fluid under a pressure of, for example, 170 pounds per square inch, or any other desired pressure, is admitted into the bottom of the working cylinder and acts on the under side of the piston 9 to effect its elevation and also that of the load suspended therefrom. When the piston reaches the end of its up or pumping stroke, the admission valve is closed by suitable trip mechanism I6 carried by the piston rod 8 and at approximately the same time, the said trip mechanism opens the exhaust valve Il, so that the elastic fluid, used in effecting the elevation of the piston, r'nay be discharged directly to the atmosphere, and without return to the compressor, as in my prior system. The opening of the exhaust valve then allows the piston and its suspended load to descend on its down or return stroke to an original pumping position. Since the exhaust valve I'I permits of the dlrect discharge of the elastic working fluid to the atmosphere, it is necessary to provide counter-balancing means whereby the down stroke may be regulated and undue acceleration thereof precluded. In my prior system, this was accomplished by maintaining a back pressure at all times on the under side of the piston in the pumping cylinder. However, in the present disclosure embodying the counter balancing cylinder, this isunnecessary, and when the exhaust.

valve I1 is open and the admission valve I5 closed, the pressure on the under side of the piston 9 is negligible. Therefore, to secure the counterbalancing of the load suspended from the piston, I provide the counter-balancing cylinder 3. The under side of the cylinder 3 is directly connected by means of a pipe line ,Ma with the tank and 'pipe line I3 and I4 so that the elastic working fluid is supplied to the counter-balancingl cylinder at the same pressure as it is supplied to the motor cylinder.

The counter-balancing cylinder, however, is devoid of valves corresponding to the I9 square inches. The pistons 9 and I8 are directly connected by means of a piston rod I9 which passes through packed bearings 20 and 2l formed in the upper end of the motor cylinder and the lower end of the counter-balancing 'cylinder respectively, so that the said pistons move in unison in their cylinders. It will be seen that whenthe exhaust valve I1 is opened and the admission valve I5 closed to provide for the descent of the pumping mechanism, the elastic working fluid under, for example, a pressure of part or upon other sudden release of load, provision is made for preventing injury to said cylinders by providing the upperend thereof with valved by-passes 22. When the pistons move upwardly beyond the lower` ends of said bypasses, the latter are .uncovered allowing the elastic working fluid to travel through said bypasses, opening the check valves 23 provided therein and entering the upper portions of said cylinders, producing an elastic cushion by which the upward movement of the pistons is gradually absorbed and injury to the apparatus prevented. Restricted vents 24 are provided in the upper ends of said cylinders, immediately below the by-passes 22 to normally relieve the upper ends of the cylinders to avoid vacuum orpressure at normal operating speed.

In view of the foregoing, it will be seen that the present invention provides a pumping mechanism of a simple yet emcient character for use in the pumping of oil wells, or in other similar and useful'capacities. It is within the scope of the invention to heat the elastic fluid used in effecting the operation of the cylinders, as disclosed in my aforesaid prior patent. While I have described and illustrated in detail one form of my the scope of the invention is not confined thereto but that variations may be made in accordance with the spirit of the following claims.

What is claimed is:

1. Motor apparatus of the character set forth comprising a motor cylinder, a. super-posed and vertically aligned counter-balancing cylinder, pistons mounted in said cylinders, the piston in the motor cylinder having a greater diameter than the piston in the counter-balancing cylinder, a rigid connection uniting said pistons for unitary movement, said pistons having a gravity load suspended therefrom, valve means governed by the stroke of the piston in the motor cylinder for a1- ternately admitting a gaseous iluid under pressure into the working cylinder below the piston therein during the up-stroke of the piston and expelling said iluid to the atmosphere upon the down stroke of said piston, cooperative means for mainf taining said working uid under a substantially constant pressure in the counter-balancing cylinder belowv its piston during both the up and downstrokes thereof, a by-pass provided in connection' with the upper end of each of said cylinders and beyond the normal stroke of the pistons therein to permit fluid to pass ,from the portion of the cylinder below said piston to that portion above, thereby forming a pneumatic check means to arrest an abnormal upward movement of said vpresent invention, yet it will be appreciated that pistons upon sudden release ofthe load suspended therefrom and a restricted breather vent adjacent the lower end of said by-pass. V

2.v Motor apparatus of the character described comprising a motor cylinder, and a counter-balancing cylinder, pistons mounted in said cylinders, said pistons being connected to each other so as to have unitary movement, valved means for admitting iluid to and exhausting iiuid from one side of said motor cylinder, means for maintaining pressure on oneside of the piston in said counter-balancing cylinder by-pass means on the opposite sides of both pistons and beyond the norlmal working strokes thereof for permitting iluid to pass from the first-mentioned sides oi' said pistons to the opposite sides thereof, thereby forming cushioning means when the pistons exceed their normal strokes and restricted breather vents in said cylinders adjacent said by-pass means.

3. Apparatus of the character described comprising a motor cylinder and a counter-balancing cylinder, pistons mounted in said cylinders and connected so as to have unitary movement, means for admitting to Aand exhausting uid from said motor cylinder, meansl for maintaining fluid under pressure on one side of the piston ln said counterbalancing cylinder by-pass means beyond the normal stroke of said last mentioned piston for permitting iluid to pass from the one side of the piston to the opposite side thereof, thereby acting as a cushioning means when said pistons exceed their normal stroke and a restricted breather vent in said last mentioned cylinder adjacent said by-pass means. I

4. Apparatus of the character described comprising a single acting motor cylinder, a piston slidably mounted therein, means adjacent one and of said cylinder for admitting to and exhausting fluid from the cylinder, restricted breather vents in said cylinder walls adjacent the other 'end thereof, -and by-pass means adjacent said other end la said cylinder and beyond the normal stroke of said pistonv for permitting passage, oi iluid from one side to the other side of the piston. 5

5.1Apparatus of the character described comprising a motor cylinder. a piston slidably mounted therein, means adjacent one end of said cylinderforV admitting to and exhausting iluid from the cylinder, breather vents adjacent the other end of said cylinder, lay-pass means adjacent said other end and beyond the normal stroke of said piston for permitting passage of iluid from une side to the other side of said piston when it exceeds its normal stroke, said vents being smaller than said by-pass means whereby to cause iluid to escape from said other side ofthe cylinder at a slower r'ate than the iluid enters through said bypass means.

6. A single acting motor device comprising a 20 cylinder, a piston slidably mounted therein, means adjacent one end of the cylinder for admitting to and exhausting iluld from said cylinder, means adjacent the other end of the cylinder for bypassing iluid from one side of said piston to the other, and a restricted breather vent adjacent the end oi' said by-pass means more remote from said other end of the cylinder.

'1. A single acting motor device comprising a .vertical cylinder, a piston slidably mounted therein, means adjacent the lower end of the cylinder for admitting to and exhausting iluid from said lcylinder, means adjacent the upper end of the cylinder for by-passing iluld from one side to the other side of said piston, and a restricted breather vent immediately below the lower end of said bypass means but beyond the normal stroke of said piston.

RICHARD H. CARR.

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