US2423507A - Planetary piston pump - Google Patents

Description

July 8, 1947. w oN 2,423,507

PLANETARY PISTON PUMP Filed Oct. 11, 1941 6 Sheets-Sheet 1 FIG.

JOSEPH B LAW TON mmvrox A TTORNEYS.

July 8, 1947. LAW-[ON 2,423,507

PLANETM KY PISTON PUMP Filed Oct. 11, 1941 6 Sheets-Sheet 2 JOSEPH B LAWQTON mvmmx.

nmmizvs.

y 1947- J. B. LAWTON PLANETARY PISTON.PUMP

Filed Oct. 11, 1941 6 Sheets-Sheet 3 FIG. .90

FIG. 9a

JOSEPH B LAW TON 'INVENTOR.

' 4 Tram/ y 8, 1947- J. B. LAWTON PLANETARY PISTON PUMP Filed Oct. 11, 1941 6 Sheets-Sheet 4 JOSEPH LAWTO/V mmvron AUMZ- A TTORNEYS.

J. B. LAWTON PLANETARY PISTON PUMP Filed Oct. 11, 1941 July 8, 1947.

6 Sheets-Sheet 5 l I /02 j /0/ /05 /0/ FIG. 16

INVENTOR.

JOSEPH B LAWTO/V flaw A TTORNEYS.

July8, 1947- J. B. LAWTON PLANETARY PISTON PUMP Filed Oct. 11, 1941 6 Sheets-Sheet 6 FIG. 2/

JOSEPH B LAWTON mmvroa.

ATTOMEYS.

Patented July 8, 1947 PLANETARY PISTON PUMP Joseph B. Lawton, Bartlesville, kla., assignor oi one-half to S. N. Van Wert, Dallas, Tex.

Application October 11, 1941, Serial No. 414,625

6 Claims. (Cl. 103-132) This invention relates to pumps and pumping mechanisms and particularly to a novel form of pumping mechanism adapted to develop a novel form of compound mechanical movement having many advantageous characteristics for pumpin purposes.

The pumping mechanism in accordance with this invention may be classified, for the purposes of this description, as of the planetary or rotary piston type, although it difiers from the more conventional forms of such types in highly important respects, as will be explained hereinafter.

One embodiment, in accordance with this invention, employs a cylinder in which is disposed an annular piston having an internally journalled eccentric which normally imparts to the piston an oscillatory movement within the cylinder. The piston, in the preferred embodiment, is anchored to the ends of the cylinder by a non-rigid anchoring connection of a form which is operative in response to the rotations of the eccentric within the piston to introduce into or combine with the normal osillatory movement of the piston a generally circular component of movement which is developed upon a radius of rotation substantially less than that of the piston. That is, although anchoring the piston against rotation within the cylinder, the anchoring connection permits a limited'peripheral movement of the piston relative to the cylinder, the peripheral movement being generally circular in form. This combination of elements, when acting upon a fluid suitably confined within the cylinder, results in a pumping action having positive displacement characteristics combined with uniflow constant discharge characteristics.

A plurality of partition or sealing members are provided between the piston and cylinder and are effective to divide the cylinder into a plurality of segmental cylinders or sectors, each of which is provided with suitably arranged suction and discharge ports for the intake and exhaust of fluid being pumped. The sealing members act primarily as retainers or dams to retain the fluid in the cylinder sectors while the fluid is being acted upon by the piston.

By the above described combination of elements, the fluid being pumped is acted upon directly by the piston in the manner of positive displacement pumps, by direct compression between the adjacent peripheral faces of the piston and cylinder during the oscillations of the piston. By means of the anchoring mechanism employed, this direct compressive action is modified by an internal generally circular peripheral movement by which the compressive action is progressively increased in the direction of rotation of the actuating eccentric, and serves to smooth out the "discharge flow of the fluid, and produces other important advantages whicch will be described hereinafter. The result is, therefore, that movement of the fluid is in no way dependent upon close clearances, or upon the degree of clearance, between the piston and cylinder, that is, no rubbing action of the piston periphery upon the cylinder wall is required to move the fluid. Also, the sealing members, unlike the vanes employed in conventional rotary pumping mechanisms wherein they act as impellers to brush or push the liquid from point to point along the cylinder periphery from suction to discharge, operate, instead, entirely as dams or partitions to retain the fluid in the chamber formed between the piston and cylinder peripheries, while it is being acted upon by the described compound movement of the piston. N0 positive means, such as conventional centering pins, thrust rollers, and the like, are required, therefore, for maintaining the sealing function of the sealing members. The sealing members may be held in sealing position simply by balancing the fluid pressure thereon, by the use of springs, and in various other ways, some of which are illustrated in the drawings and will be described hereinafter.

By the employment of the novel mechanism in accordance with this invention, it is possible to construct small, compact and very efllcient pumps, which are particularly adapted for pumping against very high heads. Such pumps will have very few working parts, the foot travel of which relative to other parts is comparatively small as compared with other types of pumps and which are, therefore, not subject to excessive wear, and may be inexpensively constructed novel type of compound pumping movement having positive displacement and uniflow discharge characteristics, and which is adapted particularly for the pumping of liquids and gases at high pressures.

A more specific object of this invention is the provision of a submergible deep well pump, for oil and water wells and the like, employing the characteristic pumping mechanism of this invention for the eflicient lifting of well fluids against high head pressures.

Other and more specific objects and advantages of this invention will become apparent from the following detailed description when read in conjunction with the accompanying drawings which illustrate several useful embodiments in accordance with this invention. It will be understood that various changes and modifications may be made in the details of this invention without departing from the scope of the appended claims, but within the spirit of this invention.

In the drawings:

Fig. 1 is a longitudinal sectional view taken along line l-l of Fig. 2 showing a pump assembly in accordance with one embodiment of this invention;

Fig. 2 is a transverse sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is a transverse view taken along line 3-3 of Fig. 1 looking toward the discharge end of the pump;

Fig. 4 is a transverse view taken along line 4-4 of Fig. 1 looking toward the suction end of the pump;

Fig. 5 is an enlarged view of a detail of the anchoring mechanism employed with the embodiment illustrated in Fig. 1;

Fig. 6 is an elevational View, partly in section, of the piston element of the pump shown in Fig.

Fig. 7 is an enlarged-.detail of another embodiment of the anchoring mechanism in accordance with this invention;

Fig. 8 is a view showing a pump, in accordance with the embodiment illustrated in Fig. 1, positioned in a pumping string in a well;

Figs. 9a, 9b, 9c, and 9d are fragmentary views of a segment of the piston and cylinder elements of the pumping mechanism of this invention, and illustrate more or less diagrammatically several positions of the working parts of the pumping mechanism during a complete cycle of the mechanism;

Fig. 10 is a longitudinal sectional view of another embodiment in accordance with this invention illustrating a form of multi-stage pump in accordance with this invention;

Fig. 11 is a transverse sectional view taken along line H-H of Fig. 10;

Fig. 12 is a similar view taken along either of lines I2l 2 of Fig. 10;

Fig. .13 is a plan view of the piston and cylinder elements of another embodiment in accordance with this invention;

Fig. 14 is a transverse view, partly in section, taken along line l4-l4 of Fig. 13;

Fig. 15 is a plan view of the piston and cylinder elements of still another embodiment in accordance with this invention, being partly broken away to illustrate the details of this embodiment;

Fig. 16 is a cross section taken along line Iii-l6 of Fig. 15;

Fig. 17 is a cross section taken along line |l-| I of Fig. 15;

Fig. 18 is a plan view of the piston and cylinder elements of a further embodiment in accordance with this invention;

Fig. 19 is an elevational view of a pump employing the pumping mechanism in accordance with this invention arranged in a horizontal mounting;

Fig. 20 is a central longitudinal section of the pump of Fig. 19 illustrating the internal arrangement of the parts; and

21 is a transverse sectional view taken along line 21-21 of Fig. 20.

Referring to the drawings and to Figs. 1 to 6 inclusive, in particular, the numeral 25 designates generally a form of pump, in accordance with one embodiment of this invention, arranged for operation in vertical position. The Pump comprises an annular casin 26, the hollow interior of which forms a cylinder 21, the lower end of which is enclosed by an end plate to be referred to as the suction plate 28, and the upper end of which is tightly enclosed by a second end plate to be referred to as the discharge plate 29. Suction plate 28 is provided with a plurality of circumferentially spaced suction passageways 30 in each of which is disposed a suitable valve such as a ball valve 3|. The suction passageways 30 extend entirely through suction plate 28 and communicate with cylinder 21 at points closely adjacent the peripheral wall of the cylinder. A suction header 32 is arranged adjacent the outer face of suction plate 28 and is provided with a plurality of suction ports 33 registering with suction passageways 30 at one end, and communicating at the other end with the interior of a tubular suction chamber 34 of any suitable form which encloses suction header 32 and provides access to a source of fluid to be pumped. Discharge plate 29 is also provided with a plurality of circumferentialiy spaced discharge passageways 35, in each of which is disposed a suitable valve such as a ball valve 3la. Discharge passageways 35 extend entirely through discharge plate 29 and communicate with cylinder 21 at points closely adjacent the cylinder wall but preferably, though not necessarily, at points which are circumierentially spaced from the points of communication of suction passageways 30 with cylinder 21. A discharge header 36 is arranged adjacent the outer face of discharge plate 2! and is provided with a plurality Of discharge ports 31 registering at one end with discharge passageways 35 and communicating at the opposite ends with a tubular discharge chamber 38 to which is connected a discharge conduit 39. A plurality of bolts 40 extends through the headers end plates and casing to connect them together tightly into a generally tubular structure of compact form.

Disposed in cylinder 2'! is a flat ring-shaped piston 4 I, the external diameter of which is somewhat smaller than the diameter of cylinder 21. The length or thickness of piston 4| is such as to provide a close sliding fit between the ends of the piston and the faces of suction plate 28 and discharge plate 29 which enclose the ends of cylinder 21. A drive shaft 42 extends axially through suitable registering openings in discharge header 36, discharge plate 29 and suction plate 28, being journalled in suction plate 28 and discharge plate 29 in bearings 43 and respectively. These bearings may be of any suitable and conventional form such as sleeve bearings, roller bearings, needle bearings or the like as may be found most expedient to use. One end of shaft 42 extends exteriorly of discharge header 36 and is provided with splines 45 for connection to a motor shaft (not shown) or to any other suitable source of power for rotating shaft 42. The portion of shaft 42 which lies within cylinder 21 has rigidly mounted thereon a cylindrical eccentric cam 46, which is journalled axially of piston 4| in a bearing 41 of any suitable type. Piston 4| thus becomes eccentrically disposed in cylinder 21. Thrust rings 48-48, surrounding shaft 42, are interposed between the opposite ends of cam 46 and the adjacent faces of suction and discharge plates 28 and 29 to take such end thrust as may develop during the operation of the pump.

Piston 4| is anchored against ordinary rotation within cylinder 21 by providing a circular recess 49 in the face of suction plate 28 adjacent the contiguous face of piston 4| in which is rigidly mounted a cylindrical pin 50 which extends into' recess 49. Pin 56 is smaller in diameter than recess 49 providing a definite amount of lateral clearance between these members which is operative to permit a secondary peripheral movement, generally circular in form, of piston 4| relative to cylinder 21, the peripheral movement being of limited radius as determined by the degree of clearance between pin 50 and the periphery of recess 49. This secondary movement has the important function referred to above and will be more fully described hereinafter.

Piston 4| is provided with a plurality of radial I slots 5| extending from end to'end of the piston and having slidably mounted therein close fitting plate-like partition or sealing members 52 which are normally held in yieldable contact with the peripheral wall of cylinder 21. by means of coil springs 53 mounted behind members 52 in slots 5|. Sealing members 52 are substantially equal in length to piston 4| so that the end surfaces of the sealing members are substantially flush with the end faces of the piston and are in close slidable contact with the adjacent faces of suction and discharge plates 28 and 29. Extending inwardly along those faces of slots 5| which are adjacent to the pressure sides of members 52 are grooves 54 (see Fig. 6 particularly) through which fiuid under pressure in cylinder 21 is introduced into slots 5| behind sealing members 52 to balance the pressure on the sealing members and ,-to aid in holding them in continuous contact with the peripheral wall of cylinder 21. It will be understood that while these sealing members 52 are illustrated as being in the form of generally rectangular plates, they may be of any other suitable form comparable in configuration to many of the forms of vane members conventionally employed in rotary type pumps.

In accordance with this invention, two or more sealing members 52 may be used, the various illustrative embodiments herein described showing four such members symmetrically arranged about the axis of the piston. At least an equal number of suction passageways 39 and discharge passageways 35, with corresponding valves 3| and 3|a, should be employed. The sealing members 52 serve to divide cylinder 21 into a plurality of cylinder sectors, the side walls of which are defined by the sealing members 52. The cylinder sectors thus formed are each provided with at least one suction passageway and one discharge passageway 35.

The above described pumping mechanism and pump operate in the following manner: When shaft 42 is coupled to a motor or other prime mover and rotated thereby, the resulting rotation of cam 46 within piston 4| permits a rolling oscillatory movement to the piston within the cylinder,

the'ends of the piston sliding on the adjacent faces of suction plate 28 and discharge plate 29.

of the pumping mechanism heretofore described.

The engagement of anchoring pin 59 in anchoring recess 49 prevents rotation of the piston within cylinder 21. However, by virtue of the difference in diameters of the pin and recess, pin 50 travels in a circular path along the peripheral wall of recess 49 in response to the movements imparted to piston 4| by the internal rotation therein of cam 46, and thereby modifies the normal oscillations of the piston by a generally circular peripheral component of movement which is developed upon a radius of rotation determined by the lateral clearance between pin 50 and recess 49, that is, upon a radius of rotation less than the radius of oscillation of piston 4|.

This novel arrangement of the parts of the pumping mechanism, by virtue of the compound movements of piston 4| developed thereby, produces a number of greatly advantageous results when employed for pumping fluids. In the first place, each segment of the piston now engages in a generally radial reciprocating movement relative to a corresponding portion of the cylinder wall and movement of the fluid, therefore, does not depend upon rolling or rubbing contact of the piston periphery with the cylinder wall, nor upon very close clearances therebetween, as is the case with the so-called cycloidal or planetary pumps heretofore designed. In the second place, sealing members 52 do not act as impellers in the ordinary sense, since only a very limited degree of peripheral movement of the sealing members is permitted by the anchoring mechanism. Instead, the periphery of each segment of the piston engages primarily in a reciprocating movement relative to the corresponding peripheral sector of the cylinder wall, alternately drawing fluid into the cylinder sector'through a suction port 30 on the inward stroke and compressing the fluid on the out-stroke and discharging it through the corresponding discharge passageway 35. This generally radial reciprocating movement of the piston segments is modified by the secondary internal generally circular component of movement developed by the rotation of pin 50 within recess 49 in response to the normal oscillations of the piston produced by the eccentric action of cam 46. This secondary movement acts to progressively increase or decrease the radially compressive action of the piston segment in the direction of rotation of the shaft 42. With this arrangement it will be seen that sealing members 52 act as sealing elements between the piston segments and the corresponding cylinder sectors, and as retainers for the fluid trapped in each cylinder sector while the fluid is being acted upon by the piston. Since there is only a limited degree of relative movement between the sealing members and the surfaces of the cylinder and piston, and

These figures are fragmentary views of one quarter segment of piston 4| and the corresponding portions of casing 26 and cylinder 21, together with small portions of the adjacent segments of the pumping mechanism. For illustrative purposes, both the suction and discharge passageways 30 and 35 are illustrated as extending lat- 7 erally through casing 26. It should be understood that although illustrative, this arrangement is entirely practical also, for,by connectin suitable suction and discharge headers to the outer ends of these passageways, this arrangement will function in substantially the same manner as that previously described. Figs. 9a to 9d represent four positions, at 90 degree intervals, of the piston segment shown, during clockwise rotation of shaft 42 and cam 46, and therefore, represent the movements of the piston segment during a complete cycle of the pumping mechanism. The parts shown bear the same identifying numerals as the corresponding parts shown in Figs. 1 to 6, inclusive. The arrows applied to the parts of the piston 4| and within recess 49 indicate the directions of movement of the piston and of pin 50 throughout the cycle, while the arrows shown in cylinder 21 and passageways 30 and 35 indicate the direction of movement of fluid during the complete cycle. From these figures it will be seen that the compound movements of the piston effected by the described pumping mechanism produces an overlapping or merging of the discharges of fluid from succeeding sectors of the cylinder and a similar overlapping of the intake movements of the fluid into successive sectors of charge is constant and non-pulsating and may be described as a uniflow movement of the fluid,

' a highly advantageous characteristic to be sought in the pumping of fluids.

The limited extent of the peripheral oscillating movements of the piston and the sealing memby noting the small changes in position of the sealing members with respect to the center lines shown on Figs. 9a to 9d. In this connection it should be noted that as a result of the limited peripheral movement of the piston and sealing members developed through the cooperation between the anchorin members, the cylinder sectors formed between adjacent sealing members may also shift peripherally relative to the cylinder wall in response to the oscillations of the piston, to an extent determined by the degree of clearance between the anchoring members.

In effecting its reciprocating movements, each of the piston segments slides between the adjacent faces of the suction plate 28 and discharge plate 29 and also slides radially relative to sealing members 52. Since all of these relatively moving surfaces are comparatively large. effective scaling is easily maintained by employing moderately close clearances therebetween, and since there is only limited relative movement between the parts, wear of the contacting surfaces is reduced to a minimum, as previously pointed out. Since sealing member 52 act merely as sealing partitions, springs 53 are not required to exert any excessive pressures and may, therefore, be relatively light and inexpensive and yet operate successfully for long periods of time. The provision of grooves 54 on the pressure sides of slots 5| admits fluid under the discharge pressure of the pump behind the members 52, thereby balancing the pressures and relieving the load on springs 53 in maintaining the sealing members in sealing contact with the cylinder periphery. The small leakage of fluid into slots 5| will also enter the space between the lower face of piston 4| and the adjacent face of suction plate 28 and serves to balance the pressure on both ends of the piston.

With regard to the anchoring mechanism comprising pin 50 and recess, 49, it should be noted that the difference in diameters of these elements should, in all cases, be not less than the throw or the length of the crank arm of cam 46, although the difierence may, if desired, be greater than the length of the crank arm of the cam. This relationship permits free movement of the piston in response to the rotations of the cam, and controls the magnitude of the sec ondary peripheral component of the pumping movement. It will be understood that the anchoring members 49 and 50 may be arranged in varied cooperating arrangements so long as the requisite clearance is maintained between the anchoring members, and the function will be the same in each case.

Fig. '7 illustrates a slight modification of the anchoring mechanism in showing an anti-friction bearing 55 mounted on the end of pin 50 which engages the wall of recess 49, in order to reduce the possible wear on these elements, although there is normally little bearing load between these members.

In the embodiments previously described, the clearance between the peripheral faces of piston 4| and cylinder 21 may be varied by varying the diameters of piston 4| or by changing the crank arm of cam 45 by changing its diameter relative to that of shaft 42. The capacity of the pump may be varied by changing the diameters or the lengths of th piston and cylinder, by varying th speed of rotation of shaft 42, or by changing the length of the crank arm of cam 46. Additional variations and modifications of the parts of the pumping mechanism and their relative arrangements will be described hereinafter in connection with the other embodiments illustrated in the drawings.

Fig. 8 illustrates a pump, such as pump 25', positioned in a pumping string in a well for lifting fluid therefrom. In this figur numeral 56 designates a well casing extending into a well, such as an oil well, in the bottom of which is a body of fluid 51 which is to be lifted to the surface. In this example, the pump is submerged in the fluid which enters the pump through suction chamber 34. Discharge conduit 39 leads to the surface and is provided adjacent the discharge end of pump 25 with an enlarged chamber 58 in which is mounted an electric motor 59 coupled to the end of shaft 42. A conductor cable 60 extends from the surface through conduit 39 to motor 59 to supply the necessary electric power thereto.

When used in a deep well pump, the pumping mechanism heretofore described has many outstanding advantages over more conventional pumps. The positive displacement characteristics developed by the mechanism enables the pump to deliver the fluid against very high heads, such as are necessarily developed in deep well pumping. and at moderate driving speeds for the piston. Since the pumping efficiency is not dependent upon having close clearances between the piston and cylinder or upon full rotation of the piston about the cylinder wall, the degre of clearance may be made sufficiently great to permit ready passage of particles of sand or other solid matter commonly present in well fluids, without causing undue scoring or abrasion of the moving parts, and without loss of efficiency of the pump. Should sand grains, for example, lodge between the ends of the sealing members and the cylinder wall, no damage or extended loss of sealing fliciency is likely because of the yieldable mounting of the sealing members, and their circumferential oscillation provided by the anchoring arrangement described would allow the sand particles to be easily and quickly dislodged under pressure of the fluid being pumped. In addition, since th pumping mechanism in accordance with this invention operates on a form of the rotary principle and has a minimum number of working partscf relatively simple construction, it is particularly adapted to give eflicient, extended, trouble-free service in deep well pumping.

Figs. 10, 11 and 12 illustrate another embodiment in accordance with this invention which is particularly adaptable for deep well pumping and for other services requiring delivery of fluid against extremly high heads. As illustrated, this embodiment is a multi-stage modification of the form previously described, and is also arranged for service as a deep well pump. Essentially this embodiment comprises three units of the pumping mechanism previously described, which are directly superimposed, one upon the other, to form three stages, as indicated by the numbered brackets in Fig. 10.

As illustrated in Fig. 10, stage I includes a suction plate 6|, an annular casing 62 enclosing a cylinder 63 in which is disposed a piston 64, and a discharge plate 65. Stage II employs discharge plate 65 as its suction plate, and on this is mounted a second annular casing 62 enclosing a second cylinder 63 and a second piston 64, and a second discharge plate 65. Stage III employs the second discharge plate 65 as its suction plate and has superimposed thereon a third casing 62 enclosing a third cylinder 63 and a third piston 64, and a final discharge plate 65. The several suction and discharge plates are substantially identical in construction, each being provided with passageways 66 and valves 61. The casings 62 for each stage are also identical in construction, as are pistons 64. Each of the pistons 64 is provided with identical anchoring means consisting of pins 68 extending into recesses 69 pcsitioned in one of the adjacent valve plates. drive shaft extends through the entire group of pump elements and is provided with a plurality of longitudinally spaced cams II for imparting movement to the several pistons 64. In order to balance the load on shaft 16,- the cams for stages I and III are positioned on the same side of the shaft v while the cam for stage II is positioned on the'shaft at an angle of 180 degrees with respect to the positionof the other cams. The anchoring means for the piston of stage II is also disposed diametrically opposite to those in stages I and III. Anti-friction bearings 72 are provided for ,journalling the shaft 16 in the several valve plates, and anti-friction bearings 13 journal the cams II in their respective pistons 64. A discharge header 14 is connected to the discharge plate of stage III and communicates with a discharge conduit 15. A suction header I6 is connected to the suction plate 6| of stage I and is provided with a tubular extension 11 into which the splined 'end 18'of drive shaft Hi extends and is coupled to a power shaft 19 journalled in the bore of extension Tl. The lower end of power shaft 19 is adapted for connection to a suitable prime mover, not shown. In this embodiment, it will be seen that drive shaft 10 is driven from the suction end of the pump rather than from the discharge end, as in the previously described embodiments.

v the pistons 64, although this modification is equally applicable to the'embodiment of Figs, 1 to 6. The sealing members are slidably mounted in radial slots 8| in casings 62 and are held in yielding contact with the periphery of the corresponding piston 64 by means of springs 82. It will be understood that pressure balancing grooves, such as groove 54 of the earlier described embodiment, may be providedin slots 8| on the pressure sides of the sealing members 80.

In operation, fluid is drawn through the suction ports in suction header 16 through passageways 66 into cylinder 63 of stage I from which it is pumped by piston 64 of that stage into passageways 66 in discharge plate 65 of stage I, thence into cylinder 63 of stage II, whence it is discharged at increased pressure through the next valve plate into cylinder 63 of stage III, wherein the pressure is further increased and the fluid finally discharged through discharge plate 65 of stage III into discharge header l4 and discharge conduit 15. The successive increases in pressure applied to the fluid in the successive stages enables the multi-stage pumps of this embodiment to discharge the fluid against extremely high heads, and this embodiment is especially applicable to pumping services in which the fiuid must be discharged against head pressures of several thousand pounds per square inch, and at high efficiencies.

It will be understood that pumps employing any number of stages may be constructed in accordance with this embod ment employing a unit of the characteristic pumping mechanism of this invention in each stage. Because of the relatively simple construction involved, friction losses through a plurality of stages will be comparatively low and the efficiencies will consequently.

be comparatively high.

Figs. 13 and 14 illustrate still another arrangement of the sealing members whereby the need for springs, such as springs 53 and 62 employed in the previously described embodiments, may be eliminated. As shown, the present embodiment includes an annular casing 63 enclosing a cylinder 84 in which is disposed a circular piston 85. A drive shaft 66 extends axially through the casing and cylinder and is provided with an eccentric cam Bl journalled internally of piston 85 in an anti-friction bearing 88. An anchoring pin 69 and an anchoring recess 96, similar in form and function to those previously described, serves to anchor piston 65 to the casing. The suction and discharge plates and valve arrangements are also similar to those previously described. Tubular slide pins 9| are disposed in tubular recesses 92 in the periphery of piston 85 and are symmetrically arrangedabout the axis thereof. Cylindrical rocker bearings 93 are arranged in cylindrical recesses 94 in the periphery of casin 83 in registering relationship to slide pins 9|. Slide pins 9| are provided with slots 95 opening toward the periphery of piston 85. A plurality of flat sealing members 96 have one end rigidly fastened by meansof pins 91 in rocker bearings 93, the other end being freely slidable in slots 95 in slide pins 9|, As piston 85 is oscillated in response to the rotations of cam 81 and engage in the limited rotational movement as determined by the clearance beofthepistona Figs. 15, 16 and 1'7 illustrate still another embodiment of the pumping mechanism as particularly adapted for submergible operation in deep well pumping. In this embodiment sealing members 98 are mounted in the annular casing 88,

and bear against the periphery of the piston. I00. This embodiment illustrates means for maintain.- ing the sealing members in sealing contact with the piston solely by fluid pressure, first by the pressure of the fluid in which the pump is submerged beiore Pumping begins, and then by the head Pressure developed after pumping is under way. For this purpose, an annular groove IN is provided in casing 00 communicating with the several slots I02 in which sealing members 98 are slidably mounted. A laterally extending passageway I03, provides communication between the exterior of the casing and annular groove III. Passageway I03 is fitted with a valve I04 which is lightly loaded by a spring- I05 to maintain the outer end of passageway I03 normally closed.

With the pump submerged in fluid in a well beiore pumping movement of the piston is begun,

the pump cylinder and forces fluid under the increased pressure from the cylinder into slots I02 and thence into groove IOI This pressure, being greater than the submergence head, iorces valve I04 to close passageway I03 and acts to provide the necessary sealing pressure for the sealing members 88.

Fig. 18 illustrates an additional embodiment of the arrangement of the sealing members, wherein sealing members I 06 are slidably mounted in slots I01 in the piston I00 and are disposed generally at right angles to each other. The operation 01' this form of the pumping mechanism is inno way diflerent from those previously described, the principal elements thereoi being otherwise substantially identical with those previously described.

Figs. 19, 20 and 21 illustrate the pumping mechanism in accordance with this invention arranged in a horizontally disposed pump I08 mounted on a base IIO. This embodiment diflers otherwise in no essential respect from the earlier described embodiments, the mechanism functioning in exactly the same manner as in the earlier described embodiments.

From the foregoing, it will be evident that the.

novel pumping mechanism of this invention may l 12 mg uses with substantially equal efilciency and advantages.

What I claim and desire to secure by Letters Patent is: I

l. A pump comprising, a tubular body forming a stationary cylinder having planar end walls and a smooth annular wall, an annular piston oi smaller diameter than said cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder, said piston having radial slots extending the full length thereof and a radial groove in the front side of each slot, a drive shaft extending axially through said cylinder, an eccentric driving cam carried by said shaft and journaled axially in said piston and adapted to impart orbital movement .thereto, anchoring means for said piston at an end thereof comprising a pin and a cooperating socket permitting but limiting an orbital movement of the pin, a plurality of circumterentially spaced sealing members extending between the periphery of said piston and said annular wall and together therewith adapted to form spaces of varying volume during the orbital movement of said piston, yieldable means in said slots ur ing said sealing members into sliding contact with a portion of said smooth cylinder wall, and suction and discharge passageways opening separately and directly from said end walls into said spaces and adapted to be alternately opened and closed by an end wall of said piston during its said movement and check valves in each of said passageways.

2. In a pump comprising, a tubular body forming a cylinder having planar end walls and a smooth annular wall, an anular piston of smaller diameter than said cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder, 2. drive shaft extending axially through said cylinder, an cecentric driving cam carried by said shaft and journaled axially in said piston and adapted to impart orbital movement thereto, anchoring means for said piston comprising a guide pin and socket and a plurality of circumferentially spaced sealing members extending between the periphery of said piston and said annular wall and together therewith adapted to form spaces of varying vol ume during the orbital movement of said piston, and suction and discharge passageways having check valves therein opening separately and directly from said end walls into said spaces, said passageways being adapted to be alternately opened and closed by action oi. said piston during its movement.

3. In a deep well pump for oil wells and the like comprising, a tubular body forming a cylinder having planar end walls and a smooth annular wall, an annular piston of smaller diameter than said cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder and free at all times from contact with the sides of said cylinder, a drive shaft extending axially through said cylinder, anv eccentric drivingcam carried by said shaft and journaled axially in said piston and adapted to impart orbital movement thereto, anchoring means for limiting the rotation of said piston, a plurality of transversely yieldable circumferentially spaced sealing members extending between the periphery of said piston and said annular cylinder wall and together therewith adapted to form spaces of varying volume during the orbital movement of said piston; and a suction passageway adjacent to the intake side oi 13 each sealing member and a discharge passageway on an opposite side of each sealing member opening separately and directly into each of said spaces and oppositely disposed check valves in each passage, saidl passageways being adapted to be alternately opened and closed by action of said piston during its said movement so as to draw fluid initially into each successive inlet thereby closing the associated outlet passage until each said space has attained its maximum capacity, and secondly and consecutively to compress and eject the entrapped fluid through each successive outlet passage until each said space has been consecutively reduced to its minimum capacity.

4. In a machine of the character described comprising, a tubular body forming a cylinder 'having planar end walls and a smooth annular wall, an annular piston of smaller diameter than said cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder having peripheral slots extending longitudinally thereof, a drive shaft extending axially through said cylinder, an eccentric cam carried by said shaft and iournaled axially in said piston for orbital movement of the piston thereon, means for permitting concentric movement of said piston but restricting the rotation thereof relative to the cylinder a plurality of circumferentially spaced sealing members slidably disposed in said'slots extending between the periphery of said piston and said annular wall 'and together therewith adapted to form spaces of varying volume during the orbital movement of said piston, and yieldable means in said slots urging said sealing members radially into sealing engagement with said cylinder well, said slots being provided with at least one radially disposed groove in the pressure side thereof to permit free flow of said fluid to and from its associated space and the slot inwardly of the sealing member.

5. In a machine of the character described comprising a tubular body forming a cylinder, a piston having smaller diameter than the cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder, a drive shaft extending axially through said cylinder and eccentrically mounted within said piston, a plurality of radially yieldable sealing members extending between the piston and the cylinder forming a plurality of sealing chambers therebetween, means holding said piston against substantial rotary motion but permitting an eccentric motion thereof, said cylinder having individual inlet and outlet ports disposed respectively adjacent each of said sealing membe and check valves for each of said ports so as to provide one inlet and one outlet port for said sealing chambers in the circumferential area between said piston and said cylinder so as to render said individual sealing chambers subject to compression and having a uni-directional flow fromadjacent sealing chambers.

6. In an oil well pump of the character described comprising a tubular body forming a cylinder, a piston having a diameter smaller than the cylinder disposed therein with the ends of said piston in transverse sliding contact with the ends of said cylinder, 9. drive shaft extending axially through said cylinder and providing an eccentric mounting for said piston, the cylindrical exterior face of the piston at its closest approach to the cylindrical interior wall of the cylinder being spaced therefrom by a clearance suflicient to pass granular material of the nature of sand, a plurality of sealing members circumferentially disposed between the walls of the piston and the cylinder forming a plurality of equal circumferentially spaced chambers of capacity variable in response to eccentric movement of said piston, means adapted to limit said piston to eccentric movement, oppositely disposed inlet and outlet ports for each chamber near one of the sealing members, and oppositely acting check valve means respectively in said inlet and outlet ports.

JOSEPH B. LAWTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENT Number Name I Date 1,935,096 Muller Nov. 14, 1933 2,243,465 Kucher May 27, 1941 1,376,291 Rolkerr Apr. 26, 1921 879,213 Tew Feb. 18, 1908 2,100,014 McCracken. Nov. 23, 1937 448,334 Gollings Mar. 17, 1891 721,863 Cook Mar. 3, 1903 2,064,635 Stern... Dec. 15, 1936 1,417,418 Smith May 23, 1922 1,594,132 Stewart July 27, 1926 FOREIGN PATENTS Number Country Date 305,700 Italy Feb. 14, 1933 19,777 Great Britain 1904 385,797 Great Britain Jan. 5, 1933 652,816 France Oct. 1928

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