Oct. 5, 1965 D. D. PHINNEY 3,209,701 PUMP lied Oct. 5, 1962

3,209,701 United States Patent Office Patenteci Oct. 5, 1965 2 3,209,701 rendered undesirable for use in the operation of the pump. PUMP Other objects and advantages will become readily ap Damon D. Plainney, Boulder, Colo., assignor to Sund parent from the following detailed description taken in ; Strand Corporation, a corporation of Hinois connection with the accompanying drawings, in which: Filed Oct. 5, 1962, Ser. No. 228,649 FIG. 1 is a vertical section of an embodiment of the 12 Caims. (C. 103-173) pump of this invention; and FEG. 2 illustrates an enlarged vertical section of an This invention relates generally to pumps of the recip embodiment of a pumping cylinder usable in the pump il Tocating type and more particularly to a cylinder block lustrated in FIG. 1. construction for Such pumps providing for lubricating O While an illustrative embodiment of the invention is of Such pumps for use in pumping of fluids having poor shown in the drawings and will be described in detail lubricating properties. herein, the invention is susceptible of embodiment in Although in the pumping of fluids having good lubricat many different forms, and it should be understood that ing properties, the working parts of piston pumps, and the present disclosure is to be considered as an exemplifica especially the side walls of the pistons and cylinders 15 tion of the principles of the invention and is not intended thereof, may receive adequate lubrication from the lubri to limit the invention to the embodiment illustrated. The cating fluid being pumped, where it is desired to pump scope of the invention will be pointed out in the appended fluids having poor lubricating properties, such as water, claims. hydrazine, hydrogen peroxide, liquid gases, etc., lubrica Referring now to the drawings, numeral 30 designates tion must be applied from another source. In using piston 20 a pump housing comprising casings 31 and 32 which are pumps such as check valved piston pumps for pumping separably joined by suitable means such as bolts, for fluids with poor lubricating properties it is sometimes example as shown at 33, threaded in the casings. A desirable to use a pump designed to reduce weight and drive shaft 34 having splines 35 for attachment to a complexity. The provision of a large swashplate angle prime mover is rotatable in the housing and is splined at in a piston pump is one design feature which may be used 39 to swashplate 21 which is mounted in swashplate bear to reduce the weight and complexity of the pump. How ings 37 and 40 and is rotatable with shaft 34. Thrust ever, the use of the large Swashplate angle produces bearing member 4 is rotatably mounted on Swashplate greater side forces on the piston in the cylinders. Such 2 by snap ring 38 and bearings 42. side forces can lead to galling and wear of the piston or A plurality of axial pistons in annular array is provided cylinder. It is desirable to minimize or eliminate the 30 within the pump and although only piston 12 is shown in effect of Such side forces. It may also be desirable in the drawings it is to be understood that each piston of other piston pumps for use in other applications to les the plurality abuts against thrust bearing member 41 at Sen Such side forces as may occur in the pumps. its non-pumping end and each is attended by other ele It is an object of this invention to provide new and use ments in an environment similar to that of piston 12 as ful means for reducing side forces between piston and 35 will be described. Piston 12 is reciprocally mounted in a cylinder in a piston pump. bronze sleeve or bushing 3 seated in a mounting block It is another object of this invention to provide a piston or crosshead 10 for the purpose of maintaining longitu pump wherein the pumping ends of the pistons reciprocate dinal alignment of the piston. A suitable lubricating oil in a transversely movable cylinder means for reduction is contained within the housing in the chamber formed by of side forces between piston and cylinder. 40 crosshead 10 and casing member 31, on the swashplate It is still another object of this invention to provide a side of crosshead 10. The chamber may be, for exam pump for pumping non-lubricating fluids including means ple, about half full of the lubricating oil and the lubricat for adequately mounting and lubricating the non-pumping ing oil is in communication with the swashplate. A ends of the pistons and including means for reducing side ported annular conduit 23 surrounds piston 12 internally forces between the piston and cylinder including the provi in sleeve 13 providing lubrication of the piston within Sion of transverse motion of the cylinder means portion crosshead 10 and particularly within bushing 13. The in which the pumping end of the piston reciprocally lubricating oil is pumped into conduit 23 by rotation of travels, the transverse motion being with respect to axis Swashplate 21 which swirls the oil and causes a static of the piston. pressure to develop in the outside of the chamber con An additional object of this invention is to provide a taining the rotating parts. This pressure forces oil to check valved piston pump for pumping non-lubricating flow radially inward wherever static passageways are fluids which includes a stationary crosshead mounted provided. The general flow of lubricating oil to conduit Within the housing and dividing the interior of the hous 23 is indicated by the dotted lines and arrows shown at ing into two separate enclosures, one containing the swash 4. Piston seal 15, which is an O-ring 15a and Teflon plate and the other containing the cylinder block, the 55 (polytetrafluoroethylene) boot 15b, constitutes a seal be pistons passing through these crossheads from cylinder tween piston 2 and crosshead 0 preventing flow of block to Swashplate which is rotatably mounted at a large pumped fluid to the opposite or non-pumping side of SWashplate angle, and to provide in such a pump means crosshead 10. Piston seal 15 is carried in a seal cavity for mounting and lubricating the pistons within the cross and is removable therefrom for replacement of the seal head, the lubricating means extending from the swash 60 upon removal of a retainer plate 15c normally abutting plate enclosure through the crosshead to the pistons, and the crosshead. to further provide in the pump means for reducing side Crosshead 10, which is composed of stainless steel, forces between the piston and cylinder and in association abuts snap ring 43, retainer plate 15c abuts crosshead 10 with the pumping ends of the pistons. and cylinder block 11 abuts retainer plate 15c. Springs, An additional object is to provide a pump in accord 65 e.g., as shown at a urge cylinder block 11, retainer ance with the foregoing objects wherein a crosshead and plate 15c and crosshead 0 against Snap ring 43 in casing cylinder block are separated from each other and wherein 32. Cylinder block 11 is also stainless steel but any there is provided ring seal means between each piston other suitable material may be used in construction of and its corresponding crosshead chamber, means for open the crosshead and the cylinder block, since the design im ing the pump housing adjacent the Swashplate and cross 70 poses neither high strength nor wear resistance require head, means for removing the crosshead and means for ments on these parts. Piston 12, one of a plurality of replacing ring Seals which may become worn or otherwise pistons is slidably mounted in a bore defined by cross 3,209,701 3 4. head 10, bushing 13 and sealing means 15. Due to the The disclosed construction is advantageous in that the angle of swashplate 21, piston 12 is side loaded with a normal one piece cylinder block construction is avoided force equal to 17.6% of the hydraulic load on the pump without very expensive alignment of the holes in the two ing end 12a of piston 12 for the design shown. blocks. The split in the block exposes the piston Seals Pumping end 12a of piston 2 extends loosely into 5 facilitating initial assembly and replacement. Such con cylinder block 11 and closely fits into pumping cylinder struction is further advantageous in that it permits the use 16 which is carried by piston 12. Pumping cylinder 16 of bronze or other suitable crosshead materials for im is positioned loosely within a recess in cylinder block 1. proved bearing conditions and further permits the use of and is free to move transversely to the reciprocal axis of hardened steel or other suitable matcrials in the pumping piston 12. Reference numeral 17 indicates the metal O cylinders without giving rise to the difficult machining to-metal seat of pumping cylinder 16 on cylinder block problem inherent in maintaining perfect alignment be 11. An alternative seat is shown in FIG. 2 wherein tween different materials normally finished by different Telfion ring 17a, which is machined to fit and bonded to machining methods, e.g., boring for bronze in the croSS pumping cylinder 16, forms a seating surface on the head and grinding followed by honing for Steel in the pumping cylinder for seating in block 11. Spring loaded 5 pumping cylinders. In order to further reduce the side discharge valve 25 assists in seating cylinder i6 in block forces of the pistons against the cylinder walls, with ref 11, especially by exerting a slight clamping force against erence to the drawings a looser fit may be provided be cylinder 16 during start-up of the pump. tween pumping cylinder 16 and piston i2 than between In operation, a prime mover attached by spline 35 to crosshead bushing 13 and piston 12 where efficiency is not shaft 34 causes rotation of swashplate 21. Rotation of 20 critical. the swashplate with counterbalance 21a on the circum The construction of the illustrated embodiment pro ference or periphery thereof, causes the lubricating oil in vides for separation of the casing 31 and 32, e.g., by re housing 30 to be hurled against the inside wall of the moval of securing bolts 33 and ease of removal of croSS housing and circulated for lubrication of moving parts head 10 by removing snap ring 43 and withdrawing cross as desired. Dotted and arrowed lines indicated at 4a 25 head 3 from the housing. The ready removability of in FIG. 1 show circulation of lubricating oil to such parts crosshead 10 provides for easier replacement of Worn as the swashplate bearings. The dotted and arrowed lines parts and especially piston seals, such as indicated at 15. indicated at 14 show circulation of lubricating oil to I claim: passage or conduit 23 for lubrication of piston 12 within 1. In a swashplate-piston pump wherein pumping ac bushing 13. The force of the side load of piston 12 is 30 tion is achieved by action of an inclined Swashplate driv taken against bushing 13 in the crosshead and lubrication ing a plurality of pistons slidably mounted in annular array between the piston and bushing is highly desirable. in axial cylinders of the cylinder block and wherein the The fluid being pumped, such as hydrazine, enters driving is a result of inclination of the Swashplate relative through inlet 19 to inlet chamber 24 in cylinder block to the axis of the array of cylinders, the improvement con 11, and is admitted through suitable intake valve 20 in prising crosshead means between said block and Said piston 12 to pumping cylinder 16. Intake valving 20 is a swashplate, said pistons slidably extending through said floating check valve retained in piston 12 by a snap ring. crosshead means, said crosshead means and pistons being During the pumping stroke of piston 12, intake valve 20 adapted to contain fluid lubricant on the SWashplate or is closed by the pressure of the fluid being pumped. Dur non-pumping side of said crosshead means and Sealing ing the intake stroke valve 20 is opened by the pressure 40 means on said crosshead to prevent lubricant from con of intake fluid in intake chamber 24, and piston 12 is re tacting the cylinders and to prevent the fluid being pumped turned by the pressure of the intake fluid in the pumping from entering the crosshead and each of Said cylinder chamber, a greater pressure than that on the Swashplate means being movable in said block transversely to the side of crosshead 10. reciprocal piston axis responsive to side loads between Pumping cylinder 16 floats in cylinder block 11 in the piston and cylinder means and each cylinder containing recess provided and is free to move transversely to the the reciprocal travel of the pumping end of a piston. reciprocal axis of piston 12, thereby substantially reducing 2. The pump of claim 1 which includes conduit means side forces between pumping end 12a of the piston and within the crosshead means and extending from the non pumping cylinder 16. Piston seal 15 serves to prevent pumping side of said crosshead means to the outer Sur the hydrazine at inlet pressure, e.g., 80 p.s. i., from leak faces of the pistons therein. ing into the lubricating oil. If desired, Teflon ring 17a 3. A pump for pumping non-lubricating fluids having acts as a suitable friction reducing seat between pumping a housing, a drive shaft, rotatably mounted through said cylinder 16 and its seat in cylinder block 1. Pumping housing, a swashplate attached to and rotatable with Said cylinder 16 is clamped on its seat in the cylinder block drive shaft, a stationary cylinder block within said hous by the valve spring acting across discharge check valve ing and opposing said swashplate, a stationary crosshead 25 and acting against the end of pumping cylinder 16. across said housing between said block and said Swash More important, the pumping cylinder 16 is urged against plate defining a block enclosure and a separate Swash its seat by hydraulic force during pumping. Thus, the plate enclosure within said housing, a plurality of cylinder maximum side load on the piston pumping end 12a, means within said block, each of said cylinder means hav where there is little if any lubrication, is that required 60 ing a pumping piston with a pumping end slidably extend to slide pumping cylinder 16 on its seat. ing therein, said cylinder means being movable in Said Although the operation of the device and the device block transversely to the piston axis responsive to side itself has been illustrated with respect to only one pis loads between the piston and cylinder means, a plu ton, i.e., piston 12, the pump includes a plurality of pis rality of chambers through the crosshead, each of Said tons of the same structure and attended by the same chambers aligned with one of said cylinder means, said structures, reciprocating axially in succession in their piston extending through said chambers to said Swash annular array about the protracted axis of the drive shaft plate, said crosshead preventing fluid flow between said giving a pumping action of the fluid entering inlet 19. enclosures, means for charging a lubricant to said swash In the pumping of the fluid, the fluid flows from inlet 19, plate enclosure, conduit means to each chamber in said through inlet chamber 24, through piston 12 and follows crosshead for conducting lubricant to each piston, said the route of the arrowed lines shown at 26 in the draw Swashplate impelling lubricant into said conduit means, ing to outlet 22 where the fluid is discharged from the and ring seal means between each piston and cylinder ad pump. Spring loaded relief valve 27 is provided to jacent the block enclosure and adapted to prevent flow permit flow of pumped fluid from outlet 22 to inlet cham of pumped fluid from said block enclosure to said swash ber 24 to relieve excessive pressure. 75 plate enclosure during operation of the pump. 3,209,701 5 6 4. In a reciprocable piston pump, a piston mounting passage, cylinders in said cylinder block freely movable blocks, at least one piston reciprocably mounted in said transversely with respect thereto and spaced from said block, a cylinder support spaced axially from said mount end of said housing so that at least a portion of one end ing block, a cylinder slidably receiving the pumping end of each of said cylinders continuously communicates with of said piston and providing a pump chamber therefor, Said Space, pistons slidable in said cylinders and engaging said cylinder being mounted on said support for move the Swashplate to be recprocated thereby as the swash ment transverse to the axis of the piston in response to plate rotates, outlet passage means in said housing com side loading of the piston, thereby to reduce wear of the municating with said space and adapted to convey fluid interengaged piston and cylinder surfaces, sealing means under discharge pressure from said housing, inlet means in said block for preventing entry of the pumped fluid 10 in said housing for delivering fluid to said cylinders on into said mounting block, means for reciprocating the piston intake strokes, outlet valve means associated with piston through intake and exhaust strokes, intake valve each cylinder including a resiliently biased check valve means for admitting fluid to the pump chamber during engaging said one end of each of said cylinders for urging piston intake strokes, and exhaust valve means for ex the other ends of the cylinders into sealing engagement hausting fluid from the pump chamber during piston ex with the cylinder block so that the check valves maintain haust strokes. the cylinders in position during the initial rotation of the 5. An axial piston pump for handling fluids which pump, and thereafter discharge fluid in the space main lack lubricating qualities, comprising, a housing, a cylin tains the cylinders in position thereby permitting trans der block mounted in the housing, a separable crosshead verse movement of the cylinders and eliminating side mounted in the housing adjacent the cylinder block, a loads thereon. Swashplate rotatably mounted in the housing adjacent 9. In a pump as defined in claim 8 and further includ the crosshead, an annular series of axially disposed pis ing, a ring mounted on said other end of each of said tons extending through the crosshead and having ends cylinders having a low co-efficient of friction compared disposed to engage the Swashplate and opposite ends ex to the cylinders and engaging said cylinder block to facili tending loosely into the cylinder block, means mounting 25 tate the transverse movement of said cylinders. the pistons in the crosshead to take substantially the en 10. In a pump as defined in claim 8 and further includ tire side loading on the pistons during pump operation, ing a crosshead having a plurality of axial cylindrical a plurality of cylinders respectively slidable on said op chambers for receiving said pistons, said crosshead being posite piston ends and providing pump chambers there fixedly mounted in said housing to absorb the radical for, said cylinders being mounted in said cylinder block 30 loads from the pistons. respectively for movement transverse to the associated 11. In a pump as defined in claim 10 wherein said piston axis thereby to reduce wear of the interengaged crosshead and said cylinder block are separable, and piston and cylinder surfaces, means for rotating the swash further including ring seal means around each piston plate to move the pistons through pump strokes, means mounted in the respective crosshead chambers, removable for moving the pistons through intake strokes, intake closure means for opening said housing adjacent the and exhaust valve means for successively admitting fluid SWashplate and crosshead, means removably mounting the to and exhausting fluid from said pump chambers as the crosshead in said housing to facilitate the replacing of Swashplate is rotated, means for lubricating said piston said seal means. mounting means in said crosshead, and sealing means on 12. In a pump as defined in claim 10, and further in said crosshead for preventing the flow of lubricant to 40 cluding means in said crosshead for supplying lubricating said cylinders. fluid to each of the pistons. 6. A pump as defined in claim 5, including abutment means in said housing adjacent said swashplate engage References Cited by the Examiner able by said crosshead, and spring means bearing against UNITED STATES PATENTS the cylinder block and housing, urging the crosshead, 45 274,391?1 8/18 Davis ------103-162 sealing means and cylinder block toward said abutment 2,238,252 4/41 Davis ------103-173 ]]C311S. ?2,374 595 4/45 Franz ------?--- 103-173 7. A pump as defined in claim 5, wherein said cylin 2,433,222 12/47 Huber ------103-173 ders are mounted in recesses in said cylinder block open 2,669,185 2/54 Tallis ------103-173 ing toward the end of said cylinder block remote from said 50 2,797,647 7/57 Floraday - 103-173 crosshead and axially movable therein, wherein each of 3,018,737 1/62 Cook et al. ------103-173 said exhaust valve means comprises a check valve nor 3,067,694 12/62 Fancher ------103-173 mally closing the remote end of said cylinder, and spring 3,090313 5/63. Budzich ------103-173 means acting against said housing and said check valve 3,160,102 12/64 Budzich ------103-173 member. 55 8. In a pump of the type having a housing, a drive FOREIGN PATENTS shaft, and a swashplate driven by the drive shaft, the im 830,959 3/60 Great Britain. provement comprising: a cylinder block mounted in said housing and spaced from one end of said housing thereby LAURENCE. V. EFNER, Primary Examiner. defining a space constituting a portion of a pump outlet 60 JOSEPH H. BRANSON, Jr., Examiner.