US1906965A - Pump working head - Google Patents

Description

May 2, 1933. s. H. HOBSON PUMP WORKING HEAD Filed June 21, 1929 2 Sheets-Sheet l May 2, 1933. s. H. HOBSON 1,906,965

PUMP WORKING HEAD Filed June 21, 1929 2 Sheets-Sheet 2 Patented May 2, 1933 UNITED STATES PATENT: OFFICE STANLEY H. HOBSON, F ROCKFORD, ILLINOIS, ASSIGNOR 'IO GEO. D. ROPEB CORPO- RATION, 0F ROCKFORD, ILLINOIS, A CORPORATION OF ILLINOIS PUMIE WORKING- HEAD Application filed June 21,

This invention relates to a working head or power head for deep well pumps.

A great variety of geared working heads have been devised by the different pump manufacturers, each being claimed to have certain advantages from the standpoints of efficieut lubrication, low maintenance cost, and smooth and quiet operation. However, it recognized that owing to the adverse operating conditions, as for example, in farm installations where the outfit is called upon to take care of the entire farm pumping service and is seldom, if ever, inspected to see if it is getting proper lubrication, working heads of that type have not been as satisfactory as might be supposed. The insuliicient lubrication gave rise to excessive wear, and the play resulting therefrom naturally caused the outfit to operate noisily. The multiplicity of moving parts employed, namely, bull gear, pinion and pinion shaft, crank pin and connecting rod, walking beam, slide block, etc., meant just that many bearings requiring lubrication, and where the lubrication was unsatisfactory, any one or more of these parts would fail, and the outfit would have to be disassembled for the replacement of the Worn-out parts, at great inconvenience, loss of time, and considerable 3Q expense to the owner. It is therefore, the

principal object of my invention to provide a hydraulically-operated working head utilizing oil as the working fluid and designed so that all of the moving parts, the number of which is reduced to a minimum, operate continuously immersed in the oil. This makes for a very substantial outfit that will last practically indefinitely. It is designed to operate etliciently even when the oil level in the tank has dropped down to the level of the intake of the oil pump, the amount of oil then left in the tank being a very small fraction of the original supply. In other words, where a geared working head, to operate quietly and with proper lubrication, had to rely upon the presence of a definite amount of oil in the reservoir, the outfit of my invention is unafiected by a considerable drop in the oil level. The hydraulic operation en- ,ables the reduction in the number of moving 1929., Serial No. 372,632.

parts from the ten or more parts required in the geared type down to practically only one moving part, namely, the working piston, aside, of course, from the pilot valve and main valve which are reciprocated in timed relation to the piston.

()tber objects of my invention, having reference to such features as the adjustability of the stops on the pilot valve stem for the purpose of changing the length of the stroke of the pump as desired, and the building of the oil pump directly on one side of the valve chest for compactness so that the cylinder with the valve chest and pump can be housed neatly in a small oil tank on the same base with the drive motor, will be pointed out in the following specification, n which reference is made to the accompanymg drawings, wherein- F lgure 1 is a plan view of an outfit made in accordance with my invention;

Fig. 2 is a side view of Fig. 1 with a portion thereof broken away, and another ortionshown in section for better illustration;

Flg. 3 1s a vertical cross-section on a slightly enlarged scale taken on the line 33 of Fig. 2;

Fl 4 is a vertical sectional detail correspon ing to a part of Fig. 3 with the pilot valve and main valve in altered positions;

Fig. 5 is a horizontal section taken on the line 55 of Fig. 3, and i Fig. 6 is a fragmentary sectional view lllustrating a difierent form of packing means in connection with the pump driving shaft.

The same reference numerals are applied to corresponding parts throughout the views.

The outfit has a base 6 arranged to be set on a suitable foundation over the well casing alongside the drop pipe 7 which, as is well known, is disposed substantially centrally in the well casing. A constant speed electric motor 8 is mounted on .one end of the base, and an oil tank 9, suitably made of sheet metal, is mounted on the other end with the hydraulically-operated working head 10 disposed therein immersed in the oil with which. the tank is filled and which constitutes the working fluid and at the same time serves as a lubricant for such of the parts of the working head as require lubrication, as w ll be pointed out presently. A light oil is suitable for the purpose in most cases, and in extremely cold weather this oil may be thinned with kerosene if need be. The work ing head comprises a casting 11 provldlng a working cylinder 12 and a valve chest 13 side by side, the casting being disposed vertically and having lugs 14 on the lower end thereof for bolting the same onto the base with the tank 9 as indicated at 15, thereby making the face plate for shafts 22 and 23 onto which the intermeshing herring- bone gears 24 and 25 are fixed. The latter work inside the casing 19 and have an intake passage 26 provided in the back plate 17 leading to the suction side thereof and a discharge port 27, also provided in the back plate 17 communicating with the pressure side thereof. The port 26 communicates at its lower end with the inside of the tank 9 close to the bottom thereof so that the pump will pump oil when there is only very little left in the tank. The discharge port 27 communicates with the intake port 28 of the valve chest 13 shown in Figs. 3

and 4 so that all of the oil pumped is used for the hydraulic operation of the working head. The shaft 23 is only a stub shaft but the shaft 22 extends through a bearing hole 29 provided in the casting 11 between the cylinder 12 and valve chest 13, and is long enough to reach through a stuffing box 30 mounted in the side wall of the tank 9. The outer end of the shaft 22 has a direct driving connection with the armature shaft 31 of the motor 8 through a coupling 32. A packing nut 33 compresses packing material into a counterbore provided in the side Wall of the valve chest 13 where the shaft 22 extends therefrom, so as to prevent the leakage of oil under pressure along the shaft 22 into the tank 9. Another packing nut 34 on the outer end of the stufling box 30 compresses packing material therein to prevent the leakage of oil from the tank along the shaft 22. Ohviously, any suitable packing means may be employed, and instead of that shown, I may employ a quick-seating packing means such as that shown in Fig. 6 consisting of a cup leather 33 on the shaft 22 in place of the packing nut 33, and another cup leather 34' on the shaft 22 at the inner end of the stuffing box 30 with a compression spring 30' disposed therebetween so that the one leather seals the pump against pressure loss, and the other leather seals the tank against oil leakage, bothleathers being held seated by the same spring. The direct drive through the coupling 32 and the sealing of the oil pump 16 against pressure losses so that the full delivery of the pump is available for the operation of the working head, are both items which, of course, tend toward higher operating efficiency.

The casting 11 of the working head 10 has a cast yoke member 35 bolted as indicated at 360m the upper end thereof, the base 37 of said part serving as a closure for the upper end of the working cylinder 12. A plate 38 is bolted, as'indicated at 39, to the casting 11 to close the lower end of the cylinder 1.2. A hollow piston 40, having a tubular rod 41 prefera 1y formed integral therewith, is reciprocable in the cylinder 12 with the rod 41 extending upwardly through a center hole 42 provided in the base 37 of the yoke 35. Rings 43 in the piston 40 reduce the oil leakage past the piston to a mimmum, so that practically all of the available pressure is effective in the operation of the piston up or down in the cylinder 12. A cup leather 44, suitably clamped in place in the bolting of the yoke member 35, fits snugly around the rod 41 and minimizes leakage from the cylinder past the rod. Any oil that manages to escape at this point will drain back into the tank so that it is not lost. The rod 41 telescopes with a guide post 45 suitably secured at its upper end in the boss 46 on the upper end of the yoke member 35 and provided with one or more piston rings 47 on its lower end to prevent the escape of oil from the inside of the piston and rod about the same. The rod 41, it will be noted, has ports 48 cored therein next to the piston 40 so as to place the inside of the piston and rod in open communication with the cylinder 12 on one side of the piston. These ports are not provided where the working head is to operate a single acting pump, and in that case the guide post 45 may or may not be used, but if it is provided it must obviously be tubular so as not to compress air in the piston. In such a construction it will be obvious that, owing to the fact that the piston rod cuts down the ultimate volumetric 1 capacity on the upper side'of the iston to such a large extent, and the fact t at there is a practically constant delivery of oil from the pump, the piston will be moved down wardly on the idle stroke much faster than it is moved upwardly on the working stroke. The advantage of this is obvious. When the ports 48 are provided, as shown, there is substantially the same area on both sides of the piston subjected to the pressure of the oil for use with a double acting pump.

delivered to the cylinder so that the piston is moved downwardly with substantially the same force as it is moved upwardly, which, of course, makes the working head suitabkle T e fact that the inside of the piston rod is in communication with the cylinder makes the ultimate volumetric capacity of the cylinder on the upper side of the piston just about the same as that on the lower side so that the piston is moved downwardly just about as fast as it is moved upwardly. The fact that the inside of the rod 41 is always filled with oil below the guide post insures adequate lubrication of the guide post because there is bound to be some oil which will not be scraped off by the rings 47. Any surplus oil escaping from the upper end of the rod 41 will, of course, drain back into the tank so that there is no waste. The rod 41 has a crosshead 49 fastened to the upper end thereof having connection at one end with the 1 plunger rod 50 of the pump and at the other end with the stem 51 of a pilot valve 52. The crosshead 49, as shown in Fig. 5, is suitably cast in two symmetrical parts. The two parts have annular ribs 53 cast in the center hub 54 thereof to fit in annular grooves 55 machined in the upper end of the rod 41. Thus, when bolts 56 are inserted through the two halves of the crosshead and tightened to cause the ribs 53 to wedge in the grooves, a rigid connection is made between the rod-and the crosshead. The outer ends of each of the halves of the crosshead provide half round hubs 57 and 58 at opposite ends so that when the two halves of the crosshead are bolted together as just stated, connection is made with the plunger rod 50 at one end and with the stem 51 at the other end. The plunger rod 50 has nuts 59 threaded on the upper end thereof above and below the crosshead 49 arranged to jam against the top and bottom of the crosshead to make the plunger rod rigid therewith. The stem 51 of the pilot valve 52, on the other hand, is arranged to have the crosshead slidable relative thereto between collars 6O adj ustably secured to the stem 51 as by means of set screws 61. On the upstroke of the piston, the crosshead comes into engagement-with the upper collar 60 to raise the pilot valve 52 to the extent indicated in dotted lines in Fig. 3, that is, to the position shown in Fig. 4. The valve is shown in full lines in F ig. 3 in the position to which it is moved by the crosshead when the latter engages the lower collar 60 at the lower end of the stroke of the piston 40. The shifting of the pilot valve port 64 communicates with the inlet port 28 while oil is exhausted from the upper port 63, and vice versa on the down stroke. In

passing, it will be noted that the plungerrod 50 has the lower end thereof entered in a guide 65 bolted, as indicated at 66, onto the head 67, which in turn has the drop pipe 7 threading therein and is bolted, as. indicated at 68, onto the side of the base 6. The head 67 has the discharge pipe 69 threaded therein, the same being led to the usual storage tank, forming a part of the usual water supply system. The lower end of the plunger rod 50 has the upper end of the pump rod 70 coupled therewith, as indicated at 71, in the usual way. An arm 72, fastened to the plunger rod 50 near the upper end thereof, provides connection between the rod 50 and another rod 73 affixed to a plunger 74 in the air compressor cylinder 75 mounted on the head 67 in the usual way. The pet cock 76 is arranged to be left open in the normal operation of the pump except when additional air is needed in the storage tank, atwhich time the pet cock is closed, so that air trapped in front of the plunger 74 on the upstroke thereof is forced into the tank on the down stroke, in a manner Well known in this art.

The valve chest 13 has the main valve 62 reciprocable therein from the position shown in Fig. 3 to that shown in Fig. 4, the movement thereof being limited by plugs77 and 78 closing the upper and lower ends of the valve chest, the same having reduced extensions 77 and 78 fitting in and closing the ends of the cylindrical bore 79 provided in said valve extending from end to end thereof. The plug 77 has a center hole 80 for the passage of the pilot valve stem 51 therethrough, the pilot valve 52 being reciprocable inside the main valve 62. Two internal annular grooves 81 and 82 are provided in the main valve 62 between three external annular grooves 83, 84 and 85 provided on said valve. One or more ports 86 in said valve afford communication between the inside thereof and the annular chamber in the valve chest afiorded by the groove 84. Likewise, one or more ports 87 in the upper end of said valve afford communication between the inside thereof and the chamber in the valve chest afforded by the annular groove 83, and one or more ports 88 in the lower end of said valve afi'ord communication between the inside of the valve and the chamber in the Valve chest afforded by the annular groove 85. About the only other feature of the main valve 62 requiring mention is the provision of a longitudinal passage 89 provided in a longitudinal boss on the upper end thereof providing communication between the internal annular groove 81 and the upper end of the valve chest above the valve 62, and another longitudinal passage 90 at the lower end of said valve affording communication between the internal annular groove 82 and the lower end of the valve chest below the valve 62. Now, the pilot valve 52 has two annular flanges 91 and 92 formed integral therewith in a predetermined spaced relation to one another having a close working fit in the bore 79 of the main valve 62. The function of the pilot valve 52 is to place the port 86 in communication either with the groove 82, as shown in Fig. 3, or with the groove 81, as shown in Fig. 4. When port 86 is in communication with groove 82, the main valve 62 is shifted hydraulically by reason of the fact that the inlet port 28 of the valve chest is then placed in communication by way of port 86, groove 82 and passage 90 with the lower end of the valve chest below the Valve 62. On the other hand, when the port 86 is placed in communication with the groove 81, as shown in Fig. 4, the inlet port 28 is placed in communication with the upper end of the valve chest 13 by way of port 86, groove 81 and passage 89. In the first case, the valve 62 is naturally moved upwardly and held in that position under pressure of the working fluid, and in the other case it is moved downwardly and held in that position.

In operation, assuming that the pilot valve 52 has been moved to the lower position shown in Fig. 3, that is, when the piston 40 arrived at the lower end of its stroke, the main valve 62 is raised by reason of the port 86 being placed in communication with the groove 82, so that oil is delivered from the inlet port 28 to the lower end of the valve chest by way of.port 86, groove 82 and passage 90. With the main valve 62 in its up per position, as it is shown in Fig. 3, oil is delivered to the lower end of the cylinder 12 from the inlet port 28 through port 64. Thus, the piston 40 is forced upwardly and, of course, raises the pump rod with it. The oil above the piston is discharged through port 63 which, in the upper position of the main valve 62, communicates with the exhaust port 93 provided in the wall of the valve chest near the lower end thereof. When the piston '40 reaches the upper end of its stroke, its crosshead 49 shifts the pilot valve 52 in the manner previously described, and the instant the port 86 is brought into communication with the groove 81, the main valve 62 is moved to the lower position shown in Fig. 4 under the action of oil delivered to the upper end of the valve chest from the inlet port 28 through port 86, groove 81 and passage 89. The shifting of the main valve 62 is practically instantaneous so that there is no noticeable dwell of the crosshead at either end of the stroke. The change in direction is furthermore not accompanied with any change in speed, that is, there is no slowing down of the crosshead as it reaches the end of the stroke and returns. With the main valve 62 in the lower position, the inlet port 28 communicates with port 63, so that oil is supplied to the upper end of the cylinder 12 to force the piston downwardly. At the same time the port 64 communicates with the exhaust port 94 provided in the wall of the valve chest near the upper end thereof so that the oil in the cylinder 12 below the piston 40 is discharged back into the tank. A shield wall 95 is preferably cast integral with the wall of the valve chest 13 to provide a passage 96 leading from the exhaust port 94 down to and past the lower exhaust port 93. It is found that without such a shield there is danger of oil being lost by reason of its discharge against the side of the tank with considerable force, the spray so produced being bound to throw some of the oil out of the tank. The pilot valve 52, it is found, will not tend to move back of its own accord from a position to which it has been moved by the crosshead 49, because there is always some oil on both sides of the flanges 91 and 92 in the bore 79 of the main valve 62. However, there is frequently a tendency for the pilot valve to move beyond the position to which it is shifted by-the crosshead owing toa building up of pressure behind the flange 91 or 92 occasioned by leakage of oil between the-relatively moving parts, due to slight discrepancies in the machining of the parts to size, or due to other causes which are sometimes difiicult to explain. For that reason, I have in certain cases found it a good practice to provide a compression spring 97 below the collar 60 and another compression spring 98 above the flange 91 fitting about the stem 51 of the pilot valve 52. These springs are fairly stiff, and when the pilot valve is shifted to its lower position, as shown in full lines in Fig. 3, the spring 97 resists any tendency for the valve to move beyond the position shown, and when the pilot valve is moved to its upper position, as shown in Fig. 4, the spring 98 keeps it from moving beyond that position. It is believed to be obvious that the mere adjustment of the collars 60 closer together or farther apart on the stem 51 of the pilot valve 52 will result in a corresponding shortening or lengthening of the stroke of the piston 40. In the particular-design shown, the stroke may be changed from ashort stroke of 2" to a long stroke of 6", but it will be evident that a much greater length of stroke might be provided for by simply providing a longer working cylinder 12 and a correspondingly longer guide 45. The outfit is, therefore, adaptable to practically any requirements that may be encountered. The water is pumped into the storage tank (not shown) until the pressure in said tank is raised to a predetermined point, whereupon a pressure regulator is arranged to break the motor circuit to stop the pumping. After that, the working head remains at rest until enough water has been drawn from the 'storage tank to cause the pressure therein to drop to a certain predetermined point, whereupon the pressure regulator completes the motor circuit again. The functioning of the ressure regulator is fully described in my atent 1,763,706, issued June 17, 1930.

It is believed the foregoing description conveys a clear understanding of my invention and all of the important objects and ad- 1 vantages. Manifestly, various changes in design and construction might be made with out seriously departing from the spirit and scope of the invention. The appended claims have, therefore, been drawn with a view to covering all legitimate modifications and adaptations.

I claim:

1. In a pumping apparatus the combination, in a unitary assembly, of a base, a motor, a tank containing a working fluid, a pump in said tank with its inlet drawing fluid directly from inside the tank, said tank, pump, and motor being supported on said base, means providing a direct driving connection between the motor and pump through the wall of said tank, a working cylinder supported on said base, a fluid operated piston in said cylinder having the rod thereof extending from the cylinder for convenient connection with the plunger rod of a pump whereby to reciprocate the plunger rod in the reciprocation of the piston, and valve mechanism in said tank communicating with the outlet of the pump and arranged to estab lish communication for said outlet alternately with the opposite ends of said cylinder to reciprocate the piston, said valve mechanism being arranged to discharge spent fluid from the cylinder directly back into the tank.

2. In a pumping apparatus the combination, in a unitary assembly, of a base, a drive motor mounted on said base, a driven unit supported on said base comprising a working cylinder having a fluid operated piston reciprocable therein, the piston having the rod thereof extending from the cylinder for convenient connection with the plunger rod of a pump, a pump for supplying working fluid under pressure rigidly supported on said cylinder, a tank containing a working fluid also supported on the base, with the pump disposed therein so that its inlet draws fluid directly from the tank, means providing a direct driving.. c0nnection between the motor and the pump through the wall of said tank, and a valve mechanism for alternately establishing communication between the outlet of the pump and opposite ends of said cylinder to deliver fluid under pressure thereto to reciprocate the piston, said valve mechanism being so disposed to discharge spent fiuifdz from the cylinder directly back into the tan 3. In a pumping apparatus, the combination with a pump for supplying workingfluid under pressure and a constant speed electric motor directly connected with the pump to drive the same at a constant speed, whereby to deliver a substantially constant volume of working fluid, of aworking cylinder, means for supporting said cylinder in vertical position adjacent the upper end of the plunger rod of a pump, a piston reciprocable in said cylinder having a rod therefor extending upwardly therefrom through the upper end of said cylinder, means to provide an operating connection between the upper end of said rod and the plunger rod, and valve means for alternately establishing communication between the pump and the upper and lower ends of said cylinder, there being a predetermined differential in the volumetric capacity above and below the piston by reason of the piston rod whereby to provide for quicker down-strokes and slower upstrokes of the plunger rod.

In witness of the foregoing I aflix my signature.

STANLEY HOBSON.

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