US2702025A - Pumping jack - Google Patents

Description

Feb. 15, 1955 R. BACCHI 2,702,025

PUMPING JACK Filed May 14, 1953 5 Sheets-Sheet 1 IN VEN TOR. For 54am Feb. 15, 1955 R. BACCHI 2,

PUMPING JACK Filed May 14, 1953 5 Sheets-Sheet 2 FIG. 2

- I N V EN TOR. 69/ 54:0

BY WM Irma/vi) Feb. 15, 1955 R, c 2,702,025

PUMPING JACK 5 Sheets-Sheet 3 Filed May 14, 1955 am r R. BACCHI PUMPING JACK Feb. 15, 1955 5 Sheets-Sheet 4 Filed May 14, 1953 INVENTOR. in 545:? BY w [2% imam Ir R. BACCHI PUMPING JACK Feb. 15, 1955 5 Sheets-Sheet 5 Filed May 14, 1953 IN VHV TOR. 24V [9661/ United States Patent PUMPING JACK Ray Bacchi, Daly City, Calif., assignor to The Pelton Water Wheel Company, San Francisco, Calif a corporation of California Application May 14, 1953, Serial No. 355,102

4 Claims. (Cl. 121-166) My invention relates to devices primarily for use in connection with oil wells having vertically reciprocable polish rods and includes a structure for hydraulically actuating the polish rod to effectuate pumping of the well.

Pumping jacks of various sorts are commercially utilized in increasing numbers as the depth of wells increases and have become increasingly complex as their development has progressed. While the complexity is in some instances entirely justifiable and necessary, in other instances the depth of the well being pumped or other surrounding circumstances make it feasible to provide a pumping jack which is somewhat simplified and can be economically and readily produced.

It is therefore an object of my invention to provide a pumping jack which is hydraulically actuated yet which is very simple in its construction and mode of operation.

Another object of my invention is to provide a hydraulic pumping jack which can be economically produced and easily and readily serviced in the field.

Another object of my invention is to provide a pumping jack which utilizes a number of relatively simple, virtually standard component parts.

Another object of my invention is to provide a pumping jack which can readily be adjusted in the field to different types of operation on different wells to which it can be attached from time to time.

A still further object of the invention is to provide a pumping jack which is effective to keep separate the oil utilized for actuating the jack and the oil which is pumped from the well.

Another object of the invention is to provide a pumping jack readily portable from site to site as a self-contained, readily operable unit.

Other objects, together with the foregoing, are attained in the embodiment of the invention described in the accompanying description and illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of a pumping jack constructed in accordance with my invention.

Figure 2 is for the most part a plan of the pumping jack shown in Figure 1, portions being in cross section on the lines 2-2 of Figure 1.

Figure 3 is a schematic showing of the various mechanical and fluid circuits of the pumping jack.

Figure 4 is a cross section to an enlarged scale, the plane of section being indicated by the line 4-4 of Figure 1. t

Figure 5 is an elevation of the structure shown in Figure 4 to the same scale but with portions broken away.

Figure 6 is an enlarged plan of the scavenge pump and its mounting.

Figure 7 is a side elevation of the structure shown in Figure 6.

Figure 8 is a detail in cross section of the jack piston.

Figure9 is a detail in cross section of the jack packing gland.

While the hydraulic pumping jack of my invention can be embodied in a number of different forms depending largely upon the particular environment in which it is to be utilized and depending also upon various other design factors, it has successfully been embodied as illustrated herein. In this instance, the pumping jack is designed for use over an oil well 6 having a polish rod 7 which extends with its axis 8 substantially vertical and is connected at its lower end to a bottom hole reciprocating pump (not shown) in the customary fashion. The polish rod 7 exists at the site and is not part of the pumping jack itself.

Included in the pumping jack is a base 9 preferably fabricated of metal shapes to constitute a skid or sled readily portable from place to place and positionable over the well 6. Mounted on the base is a removable supporting means 11 including a tripod made up of tubular legs 12, 13 and 14. The tubular legs are preferably fastened together at the top by a junction plate 16 and are of a suitable height to extend for considerably more than the necessary reciprocatory stroke of the polish rod 7. Yet, the supporting means 11 is of a height which is convenient for separate transportation, if desirable, and is readily secured by bolts 17 to the base 9.

Mounted appropriately above the junction plate 16 and with its axis coaxial with the axis 8 is a hydraulic jack including a cylinder 18 having a length somewhat greater than the predetermined stroke of the polish rod 7 and provided with a piston 19 (Figure 8) of a suitable design readily reciprocable within the cylinder 18. A piston rod 21 extends from the piston 19 to a connector 22 joined to the upper end of the polish rod 7 so that the piston 19, the piston rod 21 and the polish rod 7 all move in unison with a predetermined stroke length.

Since the piston 19 is preferably hydraulically reciprocated, and since one of the hollow legs 14 or tubular supports of the framework 11 is used as an oil conduit, there is provided an adapter head 23 situated between the junction plate 16 on the support 11 and the lower end of the jack cylinder 18. This head 23 includes an elbow 24 establishing communication between the hollow support 14 and the lower end of the cylinder 18 beneath the piston 19. The head 23 also serves as a mechanical support for the cylinder 18 on the plate 16. Since the fiow through the hollow conduit 14 is relatively rapid, the lower end of the conduit is provided with an appropriate curve 28 and non-communicating extension 29 continues the support 14 to the base 9.

As is customary in hydraulic pumping jacks, for example as shown in the patent of Ira Morgan White issued November 1 l, 1952, No. 2,617,256, there is provided a main hydraulic pump 31 connected through a drive shaft 32 having universal joints 33 and 34 therein to a driven pulley 36 mounted in journals 37 and 38 on the base 9. The pulley 36 is rotated by belts 41 connected to a drive pulley 42 rotated by a prime mover 43 such as an internal combustion gas engine having a cooling radiator 44 and the usual adjunctive machinery.

During the operation of the hydraulic pumping jack the engine 43 is customarily operated continuously and operates the pump 31 continuously. It is desired that the piston 19 be reciprocated in opposite directions alternately and hence there is provided a means for that purpose. The inlet 46 and outlet 47 of the main pump 31 are respectively connected to the body 48 of a main transfer valve 49 appropriately mounted on the base. The main transfer valve is provided with an inlet port 51 connected through a conduit 52 having manually operated main shut-off valve 53 with a duct 54 leading into the interior of a spherical balancing tank 56. The balancing tank is for the customary purpose of holding oil and air under pressure and is supported on the base 9 by a hollow cylindrical sump tank 57. The balancing tank has a common wall with the sump tank and is a sphere in order to contain the most volume with the least surface subject to heat transfer and as an economical shape for a pressure vessel. The balancing tank 56 is provided with a body 58 of oil therein and the upper portion 59 of the tank is preferably filled with a suitable gas under pressure; for example, air. An air compressor 61 connectable and disconnectable from the prime mover 43 by removable belts 62 is mounted on the base 9 so that an initial charge of pressure air can be given to the balancing tank. It is usually necessary to operate the air compressor only at infrequent intervals so that the belts 62 are shipped and unshipped according to requirement for the compressor. This simplifies the arrangement and operation of the starting air structure.

For normal running air make up, an air pump 63 is provided on the valve body 48. The main transfer valve 49 has a reciprocating valve shuttle 64 which at one end carries a plunger 66. Air for the pump 63 is derived from the atmosphere through a filter inlet 67 on the sump tank 57 and is carried from the sump tank through an inlet line 68 connected to the pump 63 through an inlet check valve 69. Air under pressure from the pump 63 is discharged through an outlet check valve 71 into a line 72 leading toward the balancing tank 56. While the line 72 can be directly connected thereto, the piping in practice is somewhat simplified by connecting the line 72 to the valve body 48 at a point communicating with the inlet 46 of the pump 31.

The main transfer valve shuttle 64 is effective in one of its extreme positions (illustrated) to transfer oil from the body 58 in the balancing tank 56 through the inlet port 51 into the inlet 46 of the pump 31. The oil under increased pressure is taken from the discharge 47 of the pump 31 and is expelled through a port 73 and a connector pipe 74 into the hollow support 14 and to the elbow 24. In the other portions of the shuttle 64, oil flows from the support 14 and the pipe 74 through a duct 76 leading into a port 78 in the valve body 48. As the main transfer valve shuttle 64 is reciprocated between its extreme positions, it serves alternately to direct oil from the balancing tank 56 through the pump 31 into the cylinder 18 beneath the piston 19 and then in the reverse order from the cylinder 18 through the pump 31 back to the balancing tank 56. The reciprocating operation of the main transfer valve 49 therefore provides the desired reciprocatory motion of the jack piston 19.

The main transfer valve 49 is relatively large in order not to inhibit the hydraulic flow. It is therefore itself actuated by a pilot valve 81 deriving actuating oil from the pump outlet 47 through a pipe 82 and controlling flow through auxiliary lines 83 and 84 extending to the opposite ends of the main transfer valve 49. Therein the auxilliary oil is effective upon the ends of the main transfer valve shuttle 64 in the customary way as shown in the mentioned patent. The valve 81 is preferably of a standard type having a valve plunger 86 having a spring detent 87 for urging the plunger 86 toward either of its extreme positions and urging it away from a neutral, center position. The effect of the detent 87 is to require the force for shifting the valve plunger 86 from one extreme position to the other to be large enough to complete the shift, once started. The valve 81 will not stall or hang up in a central, neutral position but rather will remain stationary only in either one or the other of its exereme positions.

Oil discharging from the pilot valve 81 is led through a pipe 88, having a manual, normally open shut off valve 89 and an outlet check valve 91 in it, to a drain line 92.

This is a common drain or scavenge line for various uses and leads through a normally open shut off valve 93 and a strainer 94 to a scavenge pump 96. As shown especially in Figures 2, 6 and 7, the scavenge pump 96 is conveniently a rotary force pump mounted on a swing bracket 97 t held in adjusted position by screws 98. The proper tension is thereby maintained in driving belts 99 connecting the pump 96 and the main drive shaft 32 for continuous operation of the scavenge pump when the main pump 31 operates.

Discharge from the scavenge pump is through a pipe 101 leading to a filter 102 in a conduit 103. A spring loaded check valve 104 is in a shunt line 106 around the filter to permit fluid flow when the filter resistance is excessive. The conduit 103 is provided with a check valve 107 and extends to a discharge fitting 108 located in the air space 59 of the balancing tank 56 so that the returned fluid can readily separate into air and oil.

Sometimes it is desired to send fluid from the scavenge Dump 96 directly to the sump tank 57 and so a pipe 109 is joined to the pipe 101, is provided with a manually operable valve 111 and leads into the tank 57.

There are a number of wavs for oil. or an oil and air mixture. to get into the line 92 for flow to the scavenge pump 96. If oil is to be taken directly from the sumo tank 57 for transfer to the balancing tank 56. a manuallv operated valve 112 can be o ened to allow flow throu h a branch line 113 ioined to the pipe 109 and the line 92. Also. the iack cylinder 18 and the main pump bodv 48 can be drained to the scavenge pump 96 through a line 9 114 having a manually operated valve 116 in it and extending between the pipe 74 and the line 92.

Since the packing gland 117 may leak oil, a drain line 118 extends from it through a check valve 119 to the line 92. A comparable drain line 121 extends from the packing gland 122 (Figure 9) around the piston rod, and passes through a check valve 123 to join the line 92. An overflow line 124 connects to the top of the cylinder 18 above the piston 19 and joins the line 92 so that leakage past the piston will be conserved and so that a partial vacuum, due to the descent of the piston 19 in the cylinder 18, will be intermittently effective within the line 92.

Additionally, it is deemed advisable continuously to bleed oil from the sump tank 57 into the scavenge system and so to maintain a continuous replenishment of the balancing tank oil body 58 from the make-up supply in the sump tank. The line 92 therefore extends to the sump tank 57, being connected through a check valve 126 and being provided with a small metering orifice 127 in a conduit 128 shunting a manual valve 129 which is normally closed but can be opened to augment the orifice 127.

A somewhat excessive flow through the line 92 to the balancing tank occurs in usual operation and so the balancing tank is connected through a conduit 131 directly to the sump tank 57, the flow through the conduit 131 being controlled by a normally open hand valve 132 and an automatic pressure relief valve 133. The inlet of the conduit preferably joins the balancing tank 56 at the desired liquid level and the relief valve 133 is set at the desired pressure. When that pressure is exceeded, the relief valve opens and either excess air, if the oil is low,

or excess oil, if the oil is high, is blown into the sump.

tank 57, the oil being retained therein and excess air blowing off through the inlet filter 67.

In order appropriately to actuate the valve plunger 86 and thus to control the main transfer valve 49, there is provided a special mechanism. Journaled in brackets 136 and 137 extending between the legs 13 and 14 of the support 11 is an operating shaft 138 arranged with an axis of rotation parallel to the axis 8 and having a length which is approximately the same as the predetermined stroke of the piston 19. The operating shaft 138 at its lower end is preferably provided with a lever 139 (Figures 2 and 4) at one end connected by a pivot 141 to a resilient member 142 preferably in the form of an S-shaped metal connector. The outer end of the resilient connector 142 is fastened to the valve plunger 86.

Disposed at suitable intervals along the operating shaft 138 are the split hubs 143 and 144 of a pair of radial arms 146 and 147. Preferably, the hubs 143 and 144 are axially slidable so that the hubs can be disposed in any desired location along the operating shaft 138 both with respect to their distance from each other and with respect to their distance from the base 9. To that end the operating shaft 138 is preferably made of non-circular material, such as hexagonal stock, and the hubs 143 and 144 are similarly contoured so that while the hubs are slidable along the shaft 138, they must rotate in unison therewith. Suitable clamping screws 148 and 149 anchor the hubs 143 and 144 in the desired location.

Each of the arms 146 and 147 is substantially like the other one in that is extends radially from the operating shaft 138 and lies on substantially opposite sides of the piston rod 21. In order that the radial arms 146 and 147 can be appropriately actuated, the connector 22 is formed on its exterior surface to provide a cam surface 151 of an appropriate contour extending from substantially the diameter of the polish rod 7 and of the piston rod 21 to a much larger central diameter. cam 151 is substantially constituted by a with an intermediate cylinder.

Designed to be disposed susbtantially in the path of reciprocation of the cam 151 adjacent the opposite ends of its predetermined stroke are rollers 152 and 153 respectively mounted in the forked ends of swivel axles 154 and 156. The rollers quite readily follow accurately the surfaces of the cam 151 and also of the piston rod 21 and the polish rod 7 as the cam engages the rollers and displaces the radial arms 146 and 147 to rotate the operating shaft 138. Preferably, the rollers have a somewhat resilient surface, such as a rubber, and preferably also they are of such a size and are so disposed angularly with respect to the dimensions of the piston rod and of the cam 151 that at least one roller continuously contacts at least part of the reciprocating structure to be held under some tension so that the resilient connector 142 is always under a deflection one way or the other. That imposes a load upon the valve plunger 86 in the proper direction to effectuate a complete valve shift In effect, the pair of cones with some stress left in the resilient connector 142 after the shift so that both the connector and the detent tend to hold the valve accurately in either extreme position and to make a positive valve shift despite vibration of the surrounding machinery.

The rollers 152 and 153 are located along the axis of the operating shaft 138 in such positions that as the cam 151 nears the ends of its predetermined stroke, it abuts the radially innermost roller and mechanically forces it radially outward, thereby rotating the shaft 138. At the same time, the other roller is moved inwardly to abut the piston rod 21 or the polish rod 7. This operation translates the valve plunger 86 appropriately to operate the main transfer valve 49 reversing the hydraulic flow and reversing the direction of reciprocation of the piston 19. The valve parts remain in this displaced position until the cam 151 approaches the opposite end of its stroke. At that time, the cam 151 engages the other roller, then in its path in radially inward position, and displaces that roller in a radially outward direction so revolving the operating shaft 138. This restores the other roller to its original location and simultaneously stresses the resilient connector 142 causing the valve plunger 86 to spring past its central position into its opposite location. The transfer valve 49 is thus reversed and again reverses the direction of operation of the piston 19.

With this structure it is possible, by appropriately locating the radial arm hubs 143 and 144 not only to position the rollers so that the stroke is of the desired predetermined length, but also so that the stroke reverse occurs at any desired point in the total possible travel of the piston rod 21. Usually, the predetermined stroke actually used is somewhat shorter than is possible with the length of cylinder 18 furnished. This is to standardize the pumping jack for use on wells having different stroke pumps and having wells of dilferent depth requiring the stroke reversals to occur at different locations.

In general there is provided a hydraulic pumping jack which is simple and reliable in its construction, is relatively economical to build and service, is readily portable for installation on any one of several different wells and can be readily regulated upon installation for appropriate action in connection with a particular well.

What is claimed is:

1. A pumping jack comprising a base, a hydraulic jack cylinder mounted on said base, a piston reciprocable in said cylinder through a predetermined stroke, a piston rod on said piston, a cam on said piston rod, means for supplying oil under pressure to said cylinder to reciprocate said piston, a reciprocating valve for controlling said oil supplying means, a valve operating shaft having substantially the same length as the stroke of said piston rod, means for journaling said valve operating shaft for rotation about an axis. parallel to said piston rod, arms on said valve operating shaft in the path of said cam adjacent the ends of said stroke to impart rotation to said shaft in the terminal portions of said stroke, a resilient link between said lever and said valve, and a lever fixed on said valve operating shaft for reciprocat ing said link and said valve in response to the rotation of said shaft.

2. A pumping jack comprising a base adapted to overlie a well having a vertically reciprocable polish rod, a hydraulic jack cylinder mounted on said base in axial alinement with said polish rod, a piston reciprocable in said cylinder through a predetermined stroke, a piston rod on said piston, a cam joining said piston rod and said polish rod and disposed outside said cylinder, means for supplying oil under pressure to said cylinder to reciprocate said piston, a reciprocating valve for controlling said oil supplying means, a valve operating shaft, means for journaling said valve operating shaft for rotation about an axis parallel to said piston rod, a pair of radial arms on said shaft outside said cylinder and extending to substantially opposite sides of said cam, means for securing one of said arms at any selected axial position near the upper end of said stroke, means for securing the other of said arms at any selected axial position near'the lower end of said stroke, means on said arms in the path of said cam for imparting rotation to said shaft from the reciprocation of said piston rod, and a resilient connector for reciprocating said valve in response to the rotation of said shaft.

3. A pumping jack comprising a structure including a reciprocable cam, a hydraulic jack for reciprocating said cam, means for supplying oil under pressure to said hydraulic jack, a valve having a predetermined stroke between fixed extreme positions for controlling said oil supplying means, a resilient means connected to said valve for pushing and pulling said valve through said stroke, and means operated by the reciprocation of said cam for moving said resilient means through more than said predetermined stroke for operating said valve into said extreme positions and for holding said valve in said extreme positions by the flexure of said resilient means.

4. A pumping jack comprising a structure including a cam reciprocable along a first axis, a hydraulic jack for reciprocating said cam along said first axis, means for supplying oil under pressure to said hydraulic jack, a valve for controlling said oil supplying means, a pair of arms rotatable about a second axis parallel to said first axis, means mounting said arms for rotation in unison about said second axis, means for operating said valve in response to the rotation of said arms, a pair of rollers, and means for mounting said rollers on said arms in the path of said cam and for swivelling movement about axes parallel to said first and second axes.

References Cited in the file of this patent UNITED STATES PATENTS Shaffer Apr. 4,

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