US 2789515 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
April 1957 J. E.'SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR l4 Sheets-Sheet 1 Filed Aug. 18, 1952 FIG].
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April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 18, 1952 14 Sheets$heet 2 April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 18, 1952 14 Sheets-Sheet 3 [N mas 702 J n/55 5mm 1 M; i Q24.
April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Au 18, 1952 14 Sheets-Sheet 4 FIGS K I we ,40 twi April 23, 1957 J. E, SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR INVENTO'IZ JHMES EJM/n/A April 23, 1957 J. E. SMITH 2,
VARIABLE STROKE VARIABLE PRESSURE. PUMP 0R COMPRESSOR Filed Aug. 1 8, 1952 14 Sheets-Sheet 6 FIG?- 52 FOP/V5265;
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A ril 23, 1957 J. EL SMITH 2,789,515
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April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 8, 1952 14 Sheets-Sheet 1o April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 18, 1952 14 Sheets-Sheet 11 a7 as FIGJB;
April 23, 1957 J. E. SMITH 2,789,515
VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 18 1.952 14 Sheets-Sheet 12 k s l f I //00 13%? I 1 f: ggx v g //e \%E% fi 65 7 w Jmka I 60 64 68 VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR Filed Aug. 18, 1952 J. E. SMITH A ril 23, 1957 14 Shets-Sheet 15 MWWWU TI M WWM M #0 S E M 14 Sheets-Sheet 14' [NVi/VTOP in/455 E. 5mm
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J. E. SMITH VARIABLE STROKE VARIABLE PRESSURE PUMP 0R COMPRESSOR Filed lu 18. 1952 VARIABLE STROKE VARIABLE PRESSURE PUMP OR COMPRESSOR James E. Smith, Houston, Tex.
Application August 18, 1952, Serial No. 304,935
28 Claims. (Cl. 103-161) This invention relates to pumps for handling salt water,-
Unitcd States Patent chemicals or other fluids and is more specifically directed to a pump for circulating mud or drilling fluid into an oil well while the drilling operation is being performed.
One of the principal objects of the invention is to provide a pump structure that will successfully handle abrasive fluids, fluids of different viscosities and other fluids that cause excessive wear and damage to conventional pumps.
Another object of the invention is to provide a variable stroke, variable pressure pump in which means are provided for operating the pressure-producing means in a clean lubricant that is in continuous circulation and wherein impurities are scavenged by means of centrifugal or centrifuge action of the pressure-producing lubricant or fluid within the pump.
Another object of the invention is to provide a continuous supply of lubricant or other working fluid for a pump and for automatic maintenance of the proper amount of lubricant or working fluid within the pressureproducing cylinders.
Another object of the invention is to provide a pump for handling dilferent kinds of fluids simultaneously and having means therein for sealing the fluids from each other while being pumped.
Another object of the invention is to provide a pump in which the inlet and outlet valves and the cylinder assemblies of the pump can be easily removed as a unit for inspection and repair.
Another object of the invention is to provide a pump in which all the valves are mounted in a single compact unit which will permit rapid exchange of one unit for another as well as providing means for removing all of the cylinders for repair and replacement and that includes a means for sealing the valve unit or assembly when inserted in the pump by having engaging or abutting surfaces tapered, thereby tightening and sealing the pump cylinders and valve assembly against leakage.
Another object of the invention is to provide a variable pressure, variable stroke pump whose working pressure is applied to a fluid or liquid operating at high pressure against non-yielding fluid seals and at the same time pumps fluids of a nature that cannot be pumped at high pressure with pumps having yielding seals.
A further object of the invention is to provide a variable stroke, variable pressure pump having lubricating means for the several parts thereof and wherein the pressure of the lubricant supplied to the several parts varies directly with the pressure developed by the pump and applied to the parts thereof.
A further object of the invention is to provide a variable stroke, variable pressure pump in which the pump displacement is varied in accordance with the pressure produced and wherein the adjustment is uniformly applied to both ends of the pump.
Another object of the invention is to provide a multiple cylinder positive displacement reciprocating pump having no reciprocating glands therein and wherein each cyl- 2,789,515 Patented Apr. 23, 1957 inder is provided with separator seals operating between dissimilar fluids.
Another object of the invention is to provide an improved drive and suspension for the rotating element of a radial reciprocating pump.
A still further object of the invention is to provide an inlet valve control mechanism for fluid pump externally arranged thereof.
Another and still further object of the invention is to provide a variable stroke, variable pressure radial pump provided with means for transferring the pressure-load at any stroke length to a rotating trunnion or spindle and conveying the thrust load to an annular thrust ring supporting the high pressure loads within the rotating members on antifriction bearings and without increasing the torque loads on the driving gears and power transmitting means. 1 4
Another and still further object of the invention is to provide an improved stroke control for the pump in which the rotatable element is disposed concentrically outwardly of a removable core or valve assembly having the intake and exhaust valves mounted therein. 7
The invention also consists in the provision of a lubrieating system for a pump in which the pressure of the lubricant within the working or pumping cylinders applies pressure to the pumped fluid including means for preventing the pumped fluid from intermingling with the lubricant or working fluid and in the event of an excessive amount or over supply of working fluid or lubricant,
within the cylinders provides means for releasing the excess fluid into the pumped fluid. v
- The invention also consists in the provision of means for an adjustment of the pump stroke to vary it in response to pressure fluctuation in the pump exhaust while simultaneously developing the necessary pressure in order to continue fluid movement from the pump.
The invention further consists in the provision of a variable stroke, variable pressure pump having a tapered body core 'or assembly that is forced into-a tapered opening in the cylinder assembly thereby assuring tight-fitting contact for the fluid seals against said cylinders and wherein the valves can operate at high speed by means of an actuating cam for the intake valve springs/the cam permitting closing of the intake valves before compression begins thereby avoidingthe usual hydraulic or fluid valve hammer on the valve seat, this action resulting in maximum fluid efliciency, long-valve life and smooth high-speed operation.
The invention also consists in the provisionof a pump having pressure producing cylinders or sleeves telescoping one within the other, theouter member of which displaces its volume into the smaller diameter of the inner member in which a separator head or fluid piston travels for separating the lubricant and fluid being pumped and wherein handling dissimilar materials without the two intermingling and wherein the discharge and inlet valves may be removed as a unit for inspection or repair leaving an opening in the pump center through which the cylinders and other parts may be removed or repaired.
The invention further consists in the provision of a pump for handling viscous fluids and wherein the inlet and exhaust valves may be removed as a unit for inspection and repair wherein provision is made for correctly align-f mg and tightening the valve assembly in the pump and wherein the closing time for the inlet valve may be manually adjusted.
- The invention also consists in the provision of a pump in which the pressure applied to the lubricant for the oscillating parts thereof is equal to or slightly in excess of the discharge pressure of the pump thereby assuring a supply of lubricant in said parts.
The invention further consists in the provision of a pump for handling two dissimilar fluids and wherein the pressure applied to one fluid is equal to or exceeds the exhaust pressure and wherein the fluids do not intermingle but the higher pressure fluid may be released into the lower pressure fluid by reason of wear in the pump or past a safety valve.
.In the drawings:
Fig. l is a side elevational view of the pump and prime mover shown mounted on skids,
Fig. 2 is an end view thereof,
Fig. 3 is an enlarged view of the pump looking along the line 3-3 of Fig. 1,
Fig. 4 is a sectional view taken substantially along the line 4- 4 of Fig. 3,
Fig. 5 is a sectional view taken substantially along the line 5-5 of Fig. 4,
Fig. 6 is a view similar to Fig. 5 showing the rotatable element at the beginning and termination of the intake and exhaust strokes for two of the cylinders,
Fig. 7 is an enlarged sectional view of the intake valve,
Fig. 8 is a sectional view showing the relationship of the inlet and exhaust-valves and the position of the lubricant release valve,
Fig. 9 is a sectional view taken substantially along the line 9-9 of Fig. 7,
Fig. 10 is an enlarged sectional view similar to Fig. 8 including the actuating cam for operating the inlet valve spring,
Fig. 11 is a sectional view of the adjusting mechanism for timing the inlet valve,
Fig. 12 is a sectional view taken substantially along the line 12-12 of Fig. 11,
Fig. 13 is a sectional view taken substantially along the line 13.13 of Fig. 11,
Fig. 14 is an assembly view partially in section showing the removable valve core partially disassembled,
Fig. 15 is a view partly in section showing a portion of the pump stroke-adjusting mechanism,
Fig. 16 is a side view, partly in section, of the eccentric mechanism foradjusting the pump stroke,
Fig. 17 is a sectional view taken substantially along theline 17-17 of Fig. 16,
Fig. 18 is a sectional view of a piston and cylinder assembly of the pump showing a reciprocating mechanism providing passage of lubricant or working fluid,
Fig. 19 is. a sectional view taken substantially along the line 19,19 of Fig. 18.
Fig. 20 is a schematic view showing the path and movement of lubricant and pumped fluid,
Fig. 21 is a plan view of the upper structure shown in Figs. 18 and 19,
Fig. 22 is-a side elevational view thereof,
Fig. 23 is a sectional view taken substantially along the line 2323 of Fig. 22,
Fig. 24 is a schematic view of the pump stroke-adjusting mechanism, and
Fig. 25 shows a modified form of pump stroke control mechanism.
spindles 5 rotatably mounted in the housing 4 of the pump. Each spindle is provided with a gear 6 meshing with .an annular gear 7 circumscribing the rotatable element of the pump. The pump 3 is shown as driven by two prime movers although only one may be used if so desired.
A feeder pump 8 is driven from one of the spindles 5 through gears 9 and 10. Spindles 5 constitute a part of the power transmission between the prime mover and the pump 2. The feeder pump 8 discharges into the inlet conduit 11 in communication with the removable core or valve-assembly mechanism 12 (Figs. 4 and 10).
The core mechanism or valve assembly 12 comprises a body 13 and a tubular extension 13 that is threaded into the casting or supporting member 14. The housing 13 has a plurality of inlet-valve assemblies 15 therein for controlling the flow of material to be pumped into the pump 3. Each of these valve assemblies comprises a valve seat 16 held in leakproof contact with the valvecore assembly housing 13 and is engageable by a suitable valve 17. Each valve is provided with a stem 13 extending into a guide bushing 19 secured in the valve seat 16 and surrounding the valve stem. The bushing is received in seat .16 there being a pin 29 secured in the bushing 19 which engages in a slot 21 formed in the cup member 22 for preventing rotation thereof. The stem 18 extends through a bore in the closed end of cup 22. Spring 23 is disposed between the bottom of the cup member 22 and an internal shoulder in seat 16 for normally moving valve 17 into closed position on seat 16. The cup 22 is provided with rollers 23 rotatably mounted thereon en gageable with cam 24 secured to a sectional shaft 25 which is rotatably mounted in valve body or housing 13 and extends outwardly into conduit 11 wherein it is also rotatably supported in a suitable retaining web and hearing 2.7. The cam is normally held in non-rotating or fixed position and lifts or moves cup 22 to compress spring 28 during the rotating movement of supporting member '14 permitting the intake valve to open at the beginning of the suction or intake cycle and to close same a moment before the discharge cycle begins.
For the purpose of facilitating assembly and disassembly of the intake of conduit member 11, the cam 24 is operated by sectional shafts 25 and 29. The adjoining ends of the shaft sections are suitably supported in a retaining web and bearing 27 and by a second retaining web and bearing 30 located in the part of conduit 11 external to the pump. The two sections of the shaft, 25 and 29, do not rotate during normal operation of the pump. The two sections of the shaft are connectable by a coupling which comprises a sleeve 31 forming part of the second retaining web and provided with a diametral slots 32 formed in one end thereof, one portion of which is larger in circumferential width than the other portion thereof. By means of this slot the sleeve 31 is normally engaged with a pin 33 secured to one end of the complemental shaft 25. The pin is dimensioned similarly to the slot so that it may be engaged in one position only with the cooperating part of the shaft 25.
The shaft 29 is located in external portion of the conduit l1 and is supported therein for axial movement. The outer and exposed end of the shaft is provided with a hand wheel 34 for rotating or axially moving the shaft 29, and is provided with a pointer 35 cooperating with an index mark 36 located on the housing 37 formed in conduit 11 for adjusting the position of the cam 24 thereby regulating the closing or timing of valve 17. The purpose of this adjustment is to insure the correctness of the location of cam 24- so that the closing of the valves 17 with respect to the seat 16 before the discharge pressure occurs will be accurately determined. In other Words, the pressure cycle should begin after the valve 17 has seated on the seat 16 to prevent customary valve hammer which occurs in valves which are closed by the discharge fluid. During normal operation the shaft sections are joined and are separated only during the removal of the intake conduit 11.
Attached to side plate 39 of housing 4 is a ring 40 having holes therein suitably drilled to match the hole 41 in member 13, the purpose of which is to insert a pin therein to force 13 to rotate with ring 40 for installing and withdrawing valve assembly 12. Ring 40 is normally secured to side plate 39 and retains packing ring holder 42 which does not normally rotate. The packing ring holder 42 has packings 43 therein in which conduit 11 rotates and which receives the bearing and retaining web ring 27. A ring 38 suitably secured to the packing ring holder 42 retains packings 43 in position.
Conduit 11 rotates relative to the packing 43 thus providing a fluid seal on its outer end. Provision is made for introducing a suitable lubricant into packing ring holder 42 so that the lubricant and the seals will prevent leakage of the intake fluid entering into the conduit 11. Should leakage occur it would drain off through holes 41 in packing ring holder 40 thereby revealing the presence of leakage.
The parts 13 and 13 are secured together by a split ring 45 secured to the housing 13 carrying the valve assemblies by means of a plurality of screws 46. Ring 45 abuts a collar on 13' seated against a shoulder or collar on housing 13. A pressure sealing ring 47 is provided between the two parts and checks any possible leakage of lubricant or fluid that may escape at this point. The part 13 is threaded to the supporting member 14 and the entire assembly is secured in the housing 4 of the pump by the side plate 39 suitably secured in the housing by a plurality of screws. To facilitate assembly of the pump into the housing side plates 39 and 39' are of different diameters. The smaller one would pass through the opening in the housing and would fit the bore intended for it on the opposite side. Alignment holes 69' in plate 39 and alignment hole 70' in 39' and alignment holes 39 and hole 78 and 79 in eccentrics 69 and 70 receive alignment pins (not shown) for the purpose of installing the entire mechanism in the housing.
Suitable grease seals 48 are provided for the relatively rotating parts of the pump. The pump housing contains provision for the admission of suitable lubricant to the packing ring holder 42 and suitable bolts hold the retaining ring 4-0 in position.
The valve core assembly mechanism contains a plurality of exhaust valves 49 external views thereof being shown in Fig. 14 with details of the exhaust valves in part being illustrated in Figs. 4 and 8. These exhaust valves operate as check valves and each comprises a seat 49 suitably retained within the valve core assembly housing 13. A cooperating valve 50 is slidably received in a tubular bushing or guide member 51 and a spring 52 for closing valve 50, is located between the valve 50 1 and a shoulder formed in the tubular member 51. The spring normally holds the valve in engagement with the seat 49 and allows the valve to open in response to pressure that is applied to fluid being pumped when introduced into the valve core or assembly 13.
The subject of this invention provides a separating medium or mechanism for sealing the working fluid or lubricant from the fluid or substance being pumped. One of the features of this pump is the separating means in which a slightly greater pressure is maintained on one side thereof than on the other. Lubricant or working fluid is within the cylinders and maintains pumped fluid on the opposite side of the separating means so thatwhen the separating means wears and fails to seal the pumped fluid therefrom, leakage will be into the pumped fluid by reason of the greater pressure applied to the lubricant. This prevents the pumped fluid from ever entering into and contaminating the lubricant or working fluid. Should an excessive amount of lubricant be supplied to the pump an emergency release valve in the separating means will cause discharge of the lubricant into the pump discharge thus relieving the excess lubricant. The structure for accomplishing the aforesaid desirable features will now be set forth.
A plurality of cylinder assemblies 53 is disposed about the supporting member 14, the cylinders being disposed diametrically across the supporting member in alignment and circumferentially arranged thereabout as in a radial pump. Each of these cylinder assemblies consists of a plurality of telescoping sleeves and other complemental members. 54 is an integral extension of the supporting member 14, the bore of which receives a bronze cylinder liner 55. concentrically arranged within the bronze cylinder liner is a cylinder sleeve 56 and disposed within the sleeve 56 is a cylinder liner 57. The sleeve 56 is threaded to a cross-head thrust member 58 and a suitable packing ring 59 is provided in the end of the sleeve for assisting in preventing leakage of fluid from the cylinder. The lower end of the cylinder liner 57 has a sealing ring 60 therein that is adapted to engage the valve core and assembly mechanism 12 and is intended to prevent leakage therefrom. The lower end of the cylinder liner has a tapered construction that cooperates with a complemental surface on the valve core and assembly mechanism and in order to maintain a correct alignment of the taper of the cylinder liner and the core body a pin 61 is fixed into the cylinder liner receivable in a slot 62 cut in the supporting member 14 so that upon assembly of the liner into the sleeve 56 the cooperating tapered surfaces will be in correct alignment. The radially outer end of the cylinder liner 57 is provided with a plurality of pressure-sealing rings 57 for preventing loss of pressure and escape of lubricant from within the cylinder.
The radially outer end of the cylinder liner 57 is provided with an enlarged portion for furnishing adequate wall thickness to accommodate pressure sealing means 57'. This will permit minimum thickness for the other portion of the body of the cylinder liner in which a separator or piston 63 travels which provides the means for accomplishing a seal between the two different substances Within the pump. The particular constructional features of the cylinder liner 57 provides means for obtaining a maximum volume with minimum overall diameter of the supporting member 14 by reason of the enlarged outer end of the cylinder liner.
The cylinder 54 which is an extension of the supporting member 14 receives the tubular bushing or bronze hearing 55 that facilitates a telescoping motion of the interfitting or sleeve members. The radial inward end of the cylinder liner 57 is provided with a shoulder engageable with a counterbore in the supporting member 14. The function of the pin 61 has been set forth above, which correctly aligns the several members for assembly and cooperation with the valve body 13.
The piston or separator 63 is slidably received in the cylinder liner 57 and is equipped with a resilient member 64. This resilient member may be made from a material partaking of the properties of a substance known as neoprene or some other suitable substance. This resilient member is received between the plates 65 and 66 and are clamped to the resilient member by a plurality of screws 67. The plate 65 has an extension 68 thereon that receives the radially inward end of a reciprocating assembly 69" connecting the cross head and the separator 63. The function of the assembly 69" will be described in greater detail in connection with the lubricating feature of the pump.
The mechanism for causing the above-mentioned telescoping sleeve and cylinder liner to move radially axially of each other is shown in particular in Figs. 4, l6, and 17. Disposed between the supporting member 14 and the cross-head thrust members 58 is a pair of eccentrics 69, 78 and '70, 79. A series of rollers 71 is arranged between the outer eccentrics and outer bearing raceways 72 in which shafts 73 are rotata-bly supported against the thrust rings 83. Each cylinder assembly is provided with one of the shafts 73 extending into slots 84 formed in raceways 72. Suitable mechanism is provided for holdns th shafts 73 n slots 84 c mprising circumscrihi s' thrust rings 83. A second series of rollers 74 is disposed between eccentrics 67, 7G and the supporting member 14. The eccentrics 78 and 79 are rotatably adjustable about eccentrics 69, 7e for controlling the length of stroke of sleeves 56 with respect to the cylinder liners 57, which adjustment controls the volume output of the pump as well as the pressure that is developed therein and will be more fully described later.
The supporting member 14 rotates in the bearings 74 located within the eccentrics in housing plates 3'9, 3'). The eccentrics 69 and '76 are provided with extensions 75 and 76 respectively and eccentrics '73 and 79 are of comparable width. Between the bearing surfaces the eccentrics are provided with bronze bearing liners 77 about which the eccentrics move relative to each other. The eccentrics 7% and 79 are rotatably adjustable about the eccentrics 6L and 7t? and are rotatable relative to each other for the purpose of adjusting the stroke or amount of reciprocal movement of the cylinder liner 57 with. respect to the sleeve as for controlling the output of the pump.
By referring to Fig. 16 the degree of stroke adiustment is disclosed and it will be noted that the point 8% is the center of the relatively rotatable eccentric 7S and the point 82 constitutes the center of the eccentric 69 within which the rollers 74 rotate. The point 81 is the center about which the rollers '74 rotate and also the center of the main gear '7 (see Fig. 3). The point 32 indicates the center of the eccentric surface that is complemental to the eccentric surface of the eccentric 78. From the relative locations of the several centers about which the various surfaces are drawn it is clear from the rotating positions that the telescopic movement of the sleeve member 56 and the sleeve liner 57 may be varied. Surrounding the rollers 71, as has been pointed out, is the raceway 72 with the slots 8- tormed therein and disposed about the raceway is a retaining or th ust ring 83. There is one slot in each ring, for each of the cylinders and the ends of shafts 73 are received therein. The slots 34 are circumferentially elongated and at the ends thereof pads 35 are mounted for absorbing or cushioning any shock that the shaft 73 might impose on the body of the ring or raceway 72 during the operation of t e pump.
Extending from the outer end of the cylindrical exten sion 54 integral with the supporting member 14 and the outermost perimeter thereof are cross-head openings 86 that receive bearings 87 each attached to one side of the cross-head thrust member 58 that holds the cylinder liner in correct radial ali nment for reciprocating motion relative to the cooperating structure of the pump. Supporting member 14 at its outer perimeter has the gear 7 attached thereto meshing with the gears 6 on spindles providing for the importation of rotational movement to the pump assemblies within the appropriate openings about the rollers '74. The cross-head thrust members 58 are transversely fitted to the shafts or spindles 7'3 each end of which contains a hardened collar or bushing 83 (Fig. 4) in order to provide proper contacting surfaces with the encompassing thrust rings 83. The collars provide an enlarged diameter with respect to that of the spindles with the difierence in dimension providing the leverage to assure rotation of the spindles against the bushings located in the cross-head thrust members 58.
The pump is lubricated from a suit-able source of inbricant delivered thereto under pressure and introduced into a port 89 cut in a pump exhaust fitting 90. This fitting is a part of a non-rotatable coupling 9i mounted within the supporting member 14. Lubricant is introduced into the port 89 and is then conducted through duct 92 formed in the exhaust fitting. The lubricant then flows through a cavity 93 and then through port 93 and grooves 9.4 cut; in the bushing 95 into annular groove 96 formed in the supporting member 14. This annular groove provides the necessary connections from the nonrotating portion of the structure just described and the several parts of the rotating structure. From the annular groove communication is established to each of the individual telescoping cylinders by means of a duct 97 that terminates in an annular passageway 925 closed by a ring '98 cooperating with pressure seals 33" fitted in core body 13. From the annular passageway con mum-cation is established through telescoping sleeve 99 with bushing 100 connected with a duct 161 formed in the cross head 53 and terminating in the inlet end of a sleeve assembly '69 for introducing the lubricant into the chamber 362 which is the space in the cylinders above the separator 63. The supporting member M has a boss 103 in which one end of the telescoping assembly 99 is inserted. The other end of the assembly is suitably secured in a bushing or boss 1G constituting part of the cross-head thrust member 58.
The cylindrical extension 54 of the supporting member 14 has an opening 104 therein. A fitting 195 is secured to the telescoping assembly 99 and is rigidly secured in the opening M4. The cylindrical bushing 55 has an annular groove 106 out therein that is in communication with the lubricant conducting passageway in the telescoping assembly 99 thus making it possible for lubricant to be transmitted from the passageway into the annular groove N56 for lubricating the contact surface between the bushing 55' and the sleeve 56. The telescoping assembly 99 has a passageway formed therein by suitably arranging a plurality of concentric sleeve ill! so that communication will at all times be established with the annular groove or passageway 98 and the passageway or duct 161 regardless of the telescoping position of the assembly 99.
The connecting member 6?" is provided with two spring operated check valves 168 and 139 serially arranged in a valve casing 116 and under certain. conditions is intended to discharge lubricant into the chamber 1522 and to prevent reverse flow thereof. A tube ill is connected to the valve casing Mil and forms a part of the corn necting member 69" and is telescopically received in a second tube 112 secured in the extension 63 of the upper plate as of the separator 63. Tubes 111 and 112 are provided with apertures 113 and 114 respectively. During the movement of the separator or piston 63 with respect to the cylinder liner 57 the apertures are in alignment during a predetermined time and distance of separator travel. At these times the lubricant in duct M3 and the ducts and tubes in communication therewith as previously described will be discharged into chamber 102.
Entrance of the lubricant into chamber 10?. occurs only during the suction portion of the rotation of the cylinders and only at such times as the ports 113 and 114 are in registry. This motion of the cylinders about the axis of rotation extending through the core assembly and valve core mechanism 12 and supporting member 14 occurs during each complete rotation. These results are accomplished from the fact that the cylinder sleeve 56 is of larger diameter than the internal diameter of cylinder liner 57 and displaces its cubical volume into the cylinder liner 57 and, therefore, the sealing medium or separator 63 is forced to move a greater distance than the degree of movement of reciprocation of the pressureproducing cylinder sleeve 56. This difference of movement relative to each other causes the tubes 111 and 112 to telescope one within the other. in the maximum discharge position illustrated in Fig. 18 the separator or piston 63 is at the bottom of the cylinder liner 5'7. Before the maximum intake position, during the suction degrees rotational movement, is reached, the registering port 113 and 114 are in alignment and permit the discharge of lubricant from its source through the check valve 10S 9 and 109 into chamber 102. The lubricant is under normal pressure by reason of its external supply and will, therefore, pass the check val-Mes 108 and 109.,- It will be seen that over filling cannot occur since ports 113 and 114 will automatically shut off the inflow when cavity 192 is filled.
Lubricant that is placed under compression in the chamber 102 is forced through extensible members 115. Each of these members comprises a tube 116 one end of which is suitably anchored in the plate 65 of the separator 63. This tube telescopically receives a hexagonal tube 117 one end of which is threaded into the cross-head thrustreceiving member 58. A spring 118 is disposed between a head 119 formed on the outer end of the tube 116 and abutment washer 120 secured to the radially inward end of the hexagonal tube 117. equipped with one of these springs. These springs and the centrifugal force exerted on the mass of the separator 63 tend to return the separator to retractor position after each discharge or radially inward movement of the cylinder sleeve 56. The centrifugal action produces a greater pressure on the lubricant in chamber 102 than the pressure of the pumped fluid on the opposite side of separator 63. Should any abrasive or foreign matter pass the separator 63 and enter the lubricant in chamber 102, said matter will be forced to the outer end of said chamber 1G2 adjacent to the inner surface of the cross-head thrust member 58 which forms the outer end of the chamber 102. This impure matter will be expelled from the chamber 1&2 through the duct 122 and valve 125 explained hereinafter. Relatively pure lubricant is taken into the extensible members 115 adjacent to the separator 63 and pumped through the duct 122 to lubricate the bearing liners 123 as hereinafter described.
From the foregoing it is apparent that a variable stroke, variable pressure pump including suitable trunnion pins or spindles has been provided and a source of lubrication within the pressure-producing cylinders for lubricating the spindle bearings described which flows through enclosed grooving or ducts in thrust member 58 for the shaft 73 at a pressure that varies in direct proportion to the load imposed on the thrust-receiving member 53. The mechanism provides a means for lubricant to be taken from the radially inward portion of the lubricant chamber 102 where it is free of foreign matter by reason of the centrifuge action on the rotating cylinders.
Referring now to Fig. 21 it will be observed that friction surfaces have to be lubricated at the radially outward end of the telescoping cylinders in cooperation with the thrust-receiving member 58. These members illustrate side and plan views of these structures and the mode of lubricating or means for supplying lubricant thereto is indicated either in full or dotted lines. Fig. 20 shows a circuit flow diagram for the lubricant and fluid being pumped. Cylinder sleeve 56 is part of and secured to the cross-head thrust-receiving member 58 and extensions from cylinder bores 54 project outwardly thus permitting the cross-head thrust member 58 to slide relative to '5;- tension 54. v For this purpose a series of bearings 121 are suitably secured to the sides of cross-head thrust-receiving member 58 and are slidable relative to the bore 54. The tubes 117 are in communication with ducts 122 formed in the cross-head thrust-receiving members terminating in the bearing liners 123 of shaft 73. The bearing caps 87 are arranged only adjacent the thrust raceways 72 to allow maximum outward, or reciprocating, movement within surrounding gear 7. The ducts 122' terminate in a control or metering valve 124 which consists of a check valve 125 engageable with adjustable stop 126. The adjustment of the stop determines the amount of movement or operation of the check valve and under normal conditions lubricant passes through suitable grooves cut in the perimeter of the check valve Each of the members is- 10 and thus constitutes a means of regulating the flow of lubricant through the ducts inlet.
During the compression stroke of the pump lubricant under pressure in duct 122' will tend to force the valve 125 against seat 125' against the resistance of the spring for the valve. During the time the valve 125 engages the seat no lubricant will flow through the peripheral grooves. During the suction cycle the spring will force the valve against stop 126 and the distance it moves determines the amount of lubricant to be withdrawn or metered from the cylinder. A suitable check valve 124 is to be associated with valve 124 to prevent ingress of air into duct 122 during thesuction portion of the operating cycle.
One of the objects of this invention was to produce a variable stroke, variable pressure pump wherein the stroke was controlled by the movements of the eccentric as the pressure varied within the pump and then providing for the load distribution between the eccentrics on each side of the pump and for equal distribution of the torque deflection of the actuating shafts so that both eccentrics would always be in rotational alignment. This is accomplished by simultaneously rotating the eccentrics discussed above relative to each other whereby the length of the stroke of the cylinders in their telescopic movement is regulated. This regulation being accomplished by applying the output pressure of the pump that is a direct function of the load on the separators against the pressure in the control motor that operates or adjusts the eccentrics so as to rotate them in unison and thus secure the necessary adjustment of both ends of the pump. In order to make the pump vary its volume discharge with its discharge pressure variation, the input horsepower is balanced against the discharged pressure of the pump by the action of the hydraulic strokecontrol motor in connection with the movable eccentrics within the pump. The force acting within the stroke control motor on one side of the piston therein is produced by the discharge pressure from the pump. On the other side of the piston in saidstroke control motor a compressible medium, either gas or air is operative, derived from an auxiliary chamber and at a pressure sufficient to hold the pump at its maximum or full stroke pumping position. The air pressure referred to will be the maximum pressure developed with the applied or input horsepower, which means that said air pressure will exert the necessary force within the control cylinder to hold the pump in full stroke operation until the maximum horsepower is being used. Thereafter as the pressure increases on the discharge of the pump the piston in the control cylinder will move against the compressible medium and reduce the volume or stroke length within the pump to effect an approximate balance of the input horsepower with the volume and pressure discharged from the pump.
The movement of the piston in the control motor will rotate the eccentrics relative to each other so as to bring the center thereof to the center 81 of the rotation of the gear 7 so that when the two centers meet the pump will continue to rotate, but at zero stroke. The system includes means for adjusting the pump so that it will operate between any desired pressure or volume ranges which is accomplished by varying the volume of the compressible medium in the auxiliary. chamber. In order to receive the compressed volume of the compressible medium within the control cylinder into the auxiliary chamber, the maximum pressure therein will be raised in proportion to its volumetric content to that of the stroke of the control cylinder. In order to make the pump discharge pressure at zero stroke higher the volume within the auxiliary chamber will have to be reduced. A suitable liquid can be used to fill the auxiliary chamber to a difierent level thereby reducing the cubical volume of the compressible medium within the same. Thus, when the volume of the gas in the stroke control motor has been compressed into the content of the auxiliary chamber the discharge pressure of the pump will have increased proportionately. Thus, it can be seen that as the piston in the stroke control cylinder moves to actuate the stroke change within the pump the discharge pressure from the pump as well as the volume therefrom will vary in accordance with the predetermined pressure and the volume of air contained in the auxiliary chamber.
The structure for accomplishing the stroke control of the pump just described comprises a gear sector 127 suitably secured to the eccentrics 78 and 79. Each of these gear sectors meshes with a quadrant 128 secured to a tubular shaft 131 rotatably mounted in the housing 4 of the machine. The shaft is supported in suitable bearings 130. Hub 132 of the gear sector 133 is secured to shaft 129 by key 131 at its outer end. The shaft 129 is connected to hollow shaft 131 between the eccentrics so that any deflection created by the torque force would be equalized between the actuating eccentrics thereby assuring their equal movement. The gear sector 133 meshes with gear rack 134 and is held in engagement therewith by any well-known construction. The gear rack constitutes an extension of a piston rod 135 of motor 136 mounted on the housing of the pump. Actuation of the motor 136 will reciprocate the gear rack and ultimately rotate the eccentrics 78 and 79 for changing the stroke of the pump.
The lower end of the motor 136 is connected to a pressure tank 137. Fluid is placed in the tank for the purpose of altering the volume of the air or compressible medium space above the fluid and a visible scale 138 is secured to the side of the tank for indicating the pressure in pounds per square inch and fluid level within the tank. The upper end of the flu-id motor 136 is connected to a pressure vessel 139 having a floating piston 140 therein. The liquid, preferably, a lubricant which is in communication with the upper end of the motor 136 fills the space above the piston in the fluid motor and the space above the piston 140 in the pressure vessel 139 and the space below the piston 140 is in communication with the exhaust fitting on the pump. The tank 137 is in communication with the lower end of the motor 136 by means of a conduit 141 and the upper end of the fluid motor 136 is connected to the fluid pressure 139 by means of a conduit 142 and conduit 143 is in communication with the pump exhaust.
Under some conditions of operation lubricant in the chamber 102 may escape past the sleeve assemblies and will enter a space 19 (see Fig. 9) and will then pass between 13', and supporting member 14 through a passageway cut through the teeth that join these two members and then escape through channels between the plate 39 and ultimately escape at the duct 44 from which it will be piped to a lubricant sump (not shown).
The pump described above is used primarily for the purpose of circulating mud or drilling fluid to oil wells in the course of the drilling operation. This fluid must be forced under comparatively high pressure into the oil well and as the well deepens the pump has to Work at constantly increasing pressures which operation requires a pump of variable pressure. The mud derived from a suitable source of supply, is introduced into the pump through conduit 11 by pump 8. The movement of the fluid is controlled by the valve assemblies mounted in the body member 13. The mud is introduced into the cylinder assembly by the usual pumping action.
The intake valves mounted in the core body are shown in the horizontal positions with their adjoining cylinders in Fig. 6. The inner ends of the cylinders terminate at the inner opening, adjacent the valve assembly. The separator or piston within the cylinder moves toward the valves during its discharge stroke terminating the movement at the ends of the cylinder leaving a minimum chamber space from the inside face of the separator and the face of the discharge valve. This feature is of great advantage in pumping drilling mud which sometimes becomes saturated or impregnated with gas accumulated in the mud as a result of being circulated through gas bearing formations during drilling operations. The presence of gas in the drilling mud creates a di'lficult problem because such mud will cushion or compress and the greater amount of compressing action that will take place which will cause the piston to travel on the suction stroke until the compressed gas is expanded therein suflicient to permit the suction valves to open. For this reason the cylinders are only partially filled and the fluid efliciency of the pump is seriously affected.
Fig. 6 shows the position of the several piston and cylinder assemblies at the time when two of them lay in a substantially horizontal plane one of which has travelled to the end of its discharge stroke and the other is at the beginning of the compression stroke. In Fig. 6 it is assumed that the direction of rotation is clockwise as indicated by the arrow so that the horizontal piston and cylinder shown at the right hand side of the drawing is beginning its suction stroke and its counterpart, displaced 180 degrees therefrom, is beginning the compression stroke.
In the course of operation of the pump the shaft 73 effects rotation of the bearing races 72 and the annular "thrust rings 83 by partial contact as shown in Fig. 3. One shaft is always in forward contact with the resilient element in the slot 84. Since the spindles are rotating about the center of the bearings 71 and the supporting member 14 is rotating about the center of the bearings 74, the shafts 73 rotate forward during a portion of degrees of movement and reversely during a portion of the other 180 degrees of movement. The distance the shafts move away from the resilient pads or members 85 during the aforesaid movements depends upon the length of stroke of the pump (Fig. 3). At Zero stroke which occurs at the time when the bearings 71 and 74 move about the same center all of the shafts will be in contact with the forward resilient pads 85 in the slots 84. Therefore, the distance between the centers of rotation of the bearings 71 and 74 is the radius of the stroke movement of the cylinders.
During the suction stroke the valve 17 is opened and the fluid enters the cylinder liner 57, the pump 8 and the suction created with pump 3 moving it into the cylinders. At the completion of the suction stroke the valve 17 is closed and the compression cylinder sleeve 56 then begins its compression stroke forcing the lubricant therein into sleeve 57 which moves the separator head 63 against the pumped fluid and out of the cylinder sleeve 57 past the check valve 49 into the exhaust passageway of the pump. in the event that the travel of the separator 63 is excessive by reason of an oversupply of lubricant within chamber 132 a relief valve 144 engages the top of the valve 17 thus opening same and releasing the excess lubricant into the passageway through the pump. Fig. 6 shows the position of the separator cylinder sleeves and lubricant tube parts at various stages during a compression and suction stroke.
The only way the chamber 192 can be over supplied with lubricant is by reason of wear in the tubes 111 and 112 so that lubricant will leak past their fitted surfaces. The reciprocating action of these tubes is illustrated, in particular, in Figs. 5, 6, and 18.
The pressure stroke of the cylinder sleeve 56 about sleeve 57 develops the pressure in the pump. The strokechanging mechanism described above changes the positions of the eccentrics 78 and 79' and depending upon Whether the pressure is high or low will change the pump adjustment so that the maximum volume and pressure will vary according to the applied or input horsepower. If the discharge pressure tends to increase the piston in motor 136 will move to. compress the air in tank 137 which will change the eccentric adjustment within the pump through the gear segment and rack assembly described above. In this way the output of the pump