US2604118A - Hydraulic accumulator - Google Patents

Description

July 22, 1952 E. M. GREER 2,604,118

HYDRAULIC ACCUMULATOR Filed April 25; 1946 11v vz-r/vroR EDWARD n. speak W, FORNEY Patented July 22, 1952 2,604,118 U HYDRAULIC AocUM LA roa Edward M. Greer, West Hein'pstead, N. Y., as-

signor to Greer Hydraulics, 1m, Brooklyn, N.

Application April'25, 1946, Serial No. 664,893? I i Thi invention relates to hydraulic accumulators and more particularly to the design of the oil discharge port in the accumulator and the deformable bag that is contained within the accumulator. V

In hydraulic accumulators employing compressed air or a gas within a bladder as an energy storage mechanism, a fluid is stored at a pressure greater than the air pressure charged within the bladder. In use the fluid will be discharged from the accumulator by the energy storage mechanism. In such accumulators the compressed air storage mechanism, may be a diaphragm or it maybe a deformable bag. With a deformable bag there is a very undesirable tendency for the bag'to force itself or cause the extrusion of the rubber of the bag through the fluid exhaust port after thegfiuid has been discharged, this condition causes damage or failure of the bag in use. Various modifications have been attempted to prevent damage. to the bag, such as inserting a strainer in the fluidport and such strainer being provided with a plurality of very fine apertures 3 Claims; (or. 138- 30) to minimize the tendency of the rubber to eX- charge port when the fluid in the accumulator has been discharged,

. Another object of this invention is to provide a means to protect the portion. of the deformable bag of the accumulator that is normally under an excessive strain when bearing on the fluid discharge port when the fluid has been discharged from the accumulator.

A still further object of this invention istO v providea means integral with a deformable bag in combination with the fluiddischarge port to insure the centering and guiding of the portion of the bag that should normally seal off the fluid discharge portwhen the fluid has been exhausted in the accumulator.

A still further object of this invention is to provide a fluid discharge port in an accumulator with means of draining the fluid that may be trapped'within the accumulator due to the closing of the discharge port by the accumulator bag.

A still further object of this invention isto provide a fluid discharge port in an accumulator in the form of a poppet valve seat in-combination with a poppet yalve that is afiixed to the deforme, able bag within the accumulator and in which the poppet valve seats on the fluid port to seal the, th fluid has been discharged accumulator when therefrom.

A still further objector; this invention 1 provide a deformable bag in an accumulator in, which the airport end is afiixed to the accumulator at one end thereof and in which a protective plugpf material harder than the def orm=- able bag is afiixed to the opposed end of the bag Another object of this invention is the means provide means associated with the bag in come; bination with means; associated with the shell vto" retain the closing position of the bag in perfect alignment with the fluid portwhen the-fluidyi fully discharged from the accumulator-i3 5 Other obj ectsof this invention willbe apparent, by reference to the accompanying description and.

the drawing in which:

Fig. 1 illustrates a cross sectional of the accumulator, 7 v

Fig. 2 illustrates a plan view of the taken on line 2--2 ofFig. 1, and

Fig. 3 illustrates another means of securing thiel.

protectivelbutton to the deformable bag,

i-Referring to Fig. 1, there-is illustrated an 81,07.- cumulator shell lflhav ing two apertures .Jl and. iz -atopposed ends thereof and in which a fi'tr formable bag [4 is mounted. The deformable; bag having an air port 15 at one end thereof and a re-enforcing or protective button It at the; The bag is mountedwithin the accumulator by passing through the aperture other end thereof.

i 2 of the shell l0 and passing the air valve l5 through the aperture H and threadably securing and locking the air valve 15 in place, as indicated in; Fig, I Anoil port plug I3 is mounted through aperture 12 and a split ring I9 is compressed and passed through the aperture I-2 'andthen spread.

into the position illustrated in Fig. 1 to lock the plug l8; wi thin the accumulator shell, as illus trated; A-seal .20 is positioned in-the aperture, I 2 and a lock ring 2| is threadably secured about; the plug [8 to force the seal ZIlinto a tightrfia. lationship with the aperture :12 and the periphery: of the plug l8. The'ring 2| may belocked e p ug I815 p o ided. Withthe usual threaded port 23 and on thelinaf place by a lock nut 22.

terior of the-shell the face of the plug l8; com eprises two concave shaped portions 24? and 25.

fluid po t ment andss eatir ggwith the portion 24. I The faces 24 and 25 of the plug IB'may be provided with a plurality of small grooves 21 that extend from the outer periphery of the face 25 of the plug [8 into the port 23 at the inner end oftheifaee fl, j Thus, when the plug I6 is seated against th face 24, any fluid that may be a rega ng-lower 1;

portion of the accumulator may be forced therefrom by the action of the accumulatorebagewall, in its expansion. The fluid travelling along the. grooves 21 and out through the port 23. lnTig; 2, one arrangement of the grooves 21 is illustratedebut other arrangements in which-a lesser number of' grooves] rna-y be provided may be} used last as effectivelyi I-Iow Ver, it is'fassu-r'ned-that a plurality of very fine grooves-wouldbe -pre'ferable to a fewer number of larger grooves 'as 'the fine groeves do not permit the rubber or deformable n'iaterial of, the bag to be extruded andth-us completely elose these -grooves.- Referring to Fig; a portion of th'e lower endof the deformablebag H is illustrated andin thi's'par-ticular modification-the button] 6 is mounted and afixed to -tlie' bag M by meahs o f-a threaded extension 28- which ispa'ssed through a washer 2 6-on the interior of thebag and secured to a threaded lug 21. Thus, the bag i4 is securely held between the button [6 andthe-washer'26. It is further notedin Eig- 3, that when the button It has e'en se'at'ed on the -f-ace 24-of-thejoutletplug 8 the' oiiter surface ef t'h'e def orn ableba 14' wi-llbearbn thesiirface 25 f the plug I8. without the grooves fl fluid would-be trapped within thefaccur'nulator shell, 'butwith a plurality of th grooves 21 and-, espeeiallygwith' a plurality of fine grooves that prevent'th'eextrusi lonlof the deformable material of the bag into these grooves,

the fluid trapped therein may escapeialongTthe rooves-21 and euttheenigma- 23; t may be further noted in Fig? 3=that when the huttonlfi eo-acts with the race 24 0fthe plug" 18 to giive a positive seal-ingiation the sealiwiljl not-be enl tirly {dependentupona tight rit-p tw eh t e face ofthe mash Pand 'th 'face 24 oif the plug l8:

but; in addition the portion r the deformable bag po'sitive 'seal. T 0f he rse, in' thi s' instance,

the groovesj-"lfwouldnot be provided; 'Ilowever; inf master-the usual uses of an accumulator the grooves M a re; desirable tofallow drainage'of'any trapped-fluid. Whenthe grooves 21: are-provided 3km" be notedjreferring to Fig 1,-that the normal operation Eof the-bag I 4, in use; ;causes a movement-er the plue l's "toward the port l5 and;

m ss on movement the bag 44 must {deform to allow this progressive moVement-as the fluid through;the-port-23, Unfortunately; the}? gs ltarehot always shaped in agconcentric rashie" to retainfthe bag in its "-movement ma co'r l centric pesition up and downwith the ingress ori eg ress er fluid. -lns'tead-g due to thenature or thematerial 'of the'baa-anumue to" certain N that ispressedfirmly against the face-25 rovide an'even better sealing action to-in- 4 peculiarities of the bag, because of the manner of curing and other conditions that may exist, the bag [4 takes various shapes and formations in operation. However, as a general rule the bag 14 will expel the fluid from the accumulator in a rather progressive fashion and as it reaches toward the end of its expelling stroke the lower portion of bag may meet the oil port plug in alignment therewith or entirely-out of; alignment therewith. In this particular invention the button l6 has two functions. The button [6 is shaped in a cone shape and the plug I8 is formed with -3 uidin face so that in the event the deformable bag in its expelling stroke does not movein aconcentricfashion the plug l6 will meetthe guiding face '25 and be moved back into 'a concentric position and the plug IE will seat 7 in perfect alignment within the face 24 of the plug [8. The other function of the plug I6 is to prevent the material ofthe deformable bag l4 from excessive strain or attemptedextrusionduringthe final closingofthe fiuid port 23.' "Inthis' particular instance, the plug I6 is designed to securely hold the bag in a fi' xedrelation'therewith and to restrict and re-enforce the particular portion of the bag that would normal-lybe-undr anlexcessive strain during this'closing operation.

It is to-be note-din Fig'flthat the oil port plug 18 and especially the inner end thereof has-been somewhat exaggerated in the drawing to clearlydisti-ngu-ish the faces '24 and .25 :as well as the grooves Z-Lbutin actual'use they -r'nay be much smaller and the area-on'either-side of the plug within the shell would-be considerably less to prevent the possibility of trapping-fluid'i'nthis particular area. It is apparent in Fig 1; that the greater diameter of' the plug l8 hasbeen restricted to the diameter of the aperture l2 to permitthe plug l8 to be passed through the a-p erture 12. However, with the locking ring L9, as provided, it is possible to vary-the aperture- I2 slightly-to insure the passage of the plug -I8 th erethrough Without weakening this design. It is. perhaps desirable'to redu ce'the head-portion-ofthefplug [8' as muchas possible and" still retain the features that are incor-porated i-n-thi'sinventiqin," It is' also' desirable to effeet as largean area of the lower'portion of the bag 1 4 with there-eniorcing button I 6 as is plausible-without de- 2 parting f-rom the spiritof this invention.

Referring to the air valve insert of the accumulator bag in Fig. I, it maybe noted that the-'- rubber seal or bonding is"not-disturbed at- '30' or further pressed in mounting an d; sealing-the airgvalv e IE to the-shell l0: Instead themountmg of valve 15 provides a metal to metaleontact between the shoulder} I and the cap member 32. The rubberbond'of'the'bag ll totl-ie base of-the Valve l-5-is effective over-its entire; bonded area during each stroke or Stress of operation ofthe bag, The metal tometal contact insures a tight seal withoutextrud-ingany off the'rubberinto the 'aperture-l I. Y 5 f Various changes and modifieationsnnayjbe made-tothe deformable bag at or near'E-to-the fluid'outlet port and-tothe design of the-fluid port without departing from the spirit ofthis invention and various changes may-be madeto the means of maintaining drainage for the 'fiuid that may be trapped; therein without departing: from the spirit of this-invention, andthisinventiori shall be limited only by'the appended claims.

" Whatis-claimed-is;

- =1. 1nariaccumulator comprising a shell hav' ing two ports, one of said ports forming an air port and the other of said ports forming a liquid port, a deformable partition secured within said shell separating said two ports from each other, an air valve mounted in said air port, a liquid outlet plug mounted in said liquid port, a reenforcing button afiixed to the side of the deformable partition opposite to the air port, said liquid outlet plug having a concave shaped face on the interior of said shell, said concave face being'provided with a plurality of grooves radiating from the center of said plug, said re-enforcing button being cone shaped to mate with the concave shaped face of the liquid outlet plug, and being free to move away from said liquid outlet plug with the deformation of the partition.

2. In an accumulator comprising a shell having two ports, a deformable bladder secured within said shell separating said two ports from each other, an air valve mounted in one end of said bladder and secured to one of said two ports in said shell, a liquid outlet plug having a cone shaped inner face with a central bore mounted in the other of said ports in said shell, said liquid outlet plug having the cone-shaped face that is mounted within the shell out with a plurality of fine drain grooves which extend from the outer circumference of the plug to the central bore.

3. In an accumulator comprising a shell having two ports, a deformable bladder secured within said shell separating said two ports from each other, the deformable bladder having an air valve bonded to one end thereof to control the ingress and egress of air in the bladder and a guiding button bonded to the opposite end of said bladder, said air valve being mounted in one port of the shell, a liquid outlet plug having a concaveinner face mounted in the other port of said shell, said liquid outlet plug having a shoulder on the outer periphery thereof that bears against a lock ring which in turn bears against the inside surface of the shell when the plug is mounted in the other port of the shell, means to seat said shoulder and lock ring tightly against the shell to provide a seal.

EDWARD M. GREER.

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

UNITED STATES PATENTS Number Name Date 2,299,611 Clark Oct. 20, 1942 2,300,722 Adams et al Nov. 3, 1942 2,342,356 Mercier Feb. 22, 1944 2,347,379 Teeter Apr. 25, 1944 2,380,866 Overbeke July 31, 1945 2,389,791 Lippincott Nov. 27, 1945 2,401,792 Overbeke June 11, 1946

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