US1867290A - Centrifugal pump - Google Patents

Description

July 12,1932. J v 1,867,290

CENTRIFUGAL PUMP Filed Aug. 12. 1929 ZUZ/aniar 2 Jamas if Vzzu Z 7 z) W mam/ 3 Patented July 12, 1932 UNITEDSTATES smear new .rAMEs'n. vITu, on CHICAGO, ILLInoIsnssIenoR T- WEILPUM]? '00., or cHIoAeof ILLINOIS, e oonrona'rroir OF ILLINOIS CENTRIFUGAL PUMP f Application filed August 12, 1929. semi No. 385,302. 7 i

This invention relates to improvements in centrifugal pumps. 7 v p i In the art of centrifugal pumps, particularly those of the single stage suction type,

having a single impeller, one of the sources of greatest difficulty arises because of unbalanced pressure on the impeller, which causes undesirable end thrust and consequent excessive wear of the parts. Further, he- 10 cause of the increased pressure heretofore existingon the rear side of the impellers of said types of pumps, "excessive leakage a centrifugal pump of thesingle stage suc- 0 tion type wherein the pressure'on opposite sides'of the impeller will always be substan tially perfectly balancedin all conditions of operation, to thereby eliminate undesirable end thrust and hence prolong the life of the pump.

Another object of my invention is to provide a pump of the type indicated in the preceding paragraph so constructed and arranged that there will be no increase in the cost of manufacturethereof. I

Other objects of vthe invention are to provide a pump of the type indicated which will be simple in construction, and efficient in operation. v

In the drawing forming a part of this specification, Figure 1 is a side elevational 'view of the improved impeller used in my invention. And Figure 2 is a diametrical sectional view through the casing and impeller, showing my improvements, and cor responding to the line 2-2 of Figure 1.

In carrying out my invention, I use a casing designated generally by the reference character A and an impeller indicated gen-- erally by the reference B, the latter being secured to the usual driving shaft C.

The casing A, in its general construction, may be of any suitable form, the one chosen for illustration being of the vertically split type, having an outer member 10 and an inner 'theweb is aseriesof like lifting or impeller in'g illustrated .in the drawing. Each of'the extended to thefperiphery of the web;

blades. a Each of the openings 25 ha's its in-- 1 her edge/26 thereof arranged substantially member 11. The two members'10andl1 are flanged as indicated at 12 1mm. bolted or otherwise secured together around the periphery of the casing,in a well known man-;- ner. As will be understood, the peripheral a: formation of the casing. is of the volute type, so as toprovide a peripheral discharge orifice. The member 10 isprovided with an intake orifice 13 located centrallyand havin'gftitscenter in alinement with the axis of the shaft C. The inner end of the intake orifi'ce 13 is flared toward the impeller, as clearly shown in Figure 2. The member 11 of the casing A, which is on the side opposite the intake side, is preferably provided with a hub15 in which is j ournaled the shaft C, suitable packing glands being employed, as custom- The impeller is mounted on the shaft C in; any suitable manner, the construction shown comprising a reduced section-16 onthe-shaft outward of which is a threaded end 117. The impeller has a hub 18 seated on the re 'duced section 16 of the shaft, and of slightly greater width, the impeller being retained by a nut 19 on the threaded section and the huggeing keyed to'the shaft C, as indicated at Referring to the impeller, the same is of; that type commonly termed open impeller andis of circular form, having a main centrallydisposed web 21 and on each ,side of blades or' ribs 22-22,-vfour on each: side beblades 22 isof generally arcuate form and starts at'the hub as indicated at 23. A short idistance radially outwardly from :the hub,

each blade is of reduced transversesection, as indicated at 24, and from there on is gradually flared or enlarged, the surfaces being curved on-both faces. 'The bladesfas clear from Figurel, are uniformly spacedand' are Adjacent the hub, the impeller B is also provided with a series of openings or apertures 25*25, four aperturesbeing illustrated and .each located between" two adjacent tangent to the hub, the remainder of the edge of thenopening being constituted by a composite curve, as shown in Figure 1., i 7 Referring more particularly :to Figure 2, it will be noted that the vertical portions of the members 10 and 11 of thecasing are so spaced Ithat the same are "as closely .ad- .jacent'thesurfaces of the blades as possible without actually recessed or cut back portion 27 is disposed directly opposite the intake orificeilfleandiis: of an area corresponding to the area of the r 5 innermost flared end 'l lof the intake orifice.

, The recessed orout back..portion27 provides "assuppleinental 'ch'anri'bcr in communicat'ion' with t'he main chani'ber offthe casing,

- as willbe:iapparent; 'and'is of; extreme impnrtancein eflecting-balancedgpressures on v "t'hetwoisidesof'the impeller; In actualprac- ;tice,the'total orfcombined areas of theapertures will 'be'imadesuch that they will permit the'reasyarid' ready; pa'ssagefof at least 25 'ihalf "the volume of the "liquid being handled 'thegpumpftoithe'back or far'sidegof' the 'fin' peller. By'reason of the auXiliaryichamber 27, "an increased space is thus provided fofthevolume' of'liguidpassingithrough the 3 i'ap'erture's J25,and itherebysufiicient room is 'obtaineditoaccommodatethatgportion of the "ii giiifdfpassizngithrough 'thein' peller' to insure the *saine"pressure'on the bac'k' or farside of the impelleras on the intake side of theiimlpeller, in that jp'ortiron er fth'e chamber imimiediatly adj acent the flared portion 14 of certain amount ofirnpedanc'e arises "to the 'passageiof. the .liquid through the apertures :of "theimpeller and were there :no' increased "space "behind the impeller to accommodate :the' liquid passingthrough the" apertures, the *pressures'on opposite sides 'would not be alike, and hence there would still remain the 4 undesirable en d'ithrust. By my arrangement oftheauiiliarychamber andiproportioning ydfthe"aperturesg25 sons to accommodate at leasflhalfofthe?liquidlbeing handled bi ths pump, the pressures are '''balanced and midesirableendthrusttherebyeither practical- Zlly eiirnin'atedorso minimized as 'tobenegligij In thisconnetion it is to be' understood that the balancing'efl 'ect ab ove' referred toiis obtained under varying conditions of1opera- V *tion{thatis,where'the'liquid.maycomeinto [the intake orifice under pressure ggreater *than theatmosphere or'less.

not be compressed so tightly as heretofore and hence wear on the shaft and leakage are both reduced and the life of the pump increased.

From the preceding description, taken in connection withthe drawing, it will be seen that my improvements do not involve any additional cost in the manufacture of the being in contact. Themem ill of ethecasing 1is recessed-or cut-aback at its central portion, asindicatedwat 27; The

pump and that the maximum efficiency for chambers in accordance with the description :outlin'ed.

Although I have herein shown and described what I now consider the preferred manner of carrying out the invention, the

' same is merely illustrative andI contemplate 'combination with a' casing having a centrally disposed intake orifice in one sidethereof and a peripheral discharge orifice; of an open type impeller having a centrally disposed web and curved iinpellingblades on opposite sides thereof ;'and a shaft onwhich sai'd impeller mounted; the shaftbeing rotatably mounted'inthe casing, said casing, on the side'opposite sa d int ake orifice and 1n ahnement'therewith, being providedwith an auxiliary cham "berloffsetfrom and m free communication with the main chamber of the casing'in' which "the impeller "rotates; the "web of the. impeller being also provided withaplurality o'faper-v said'intake orificeand auxiliary chamber, the

uid to pass freely therethrough when the puinp is in operation, said auxiliarychamber PTOVlCllDg an .increasedspace for accommo- 'datio'n anfd chngeoffdirection of'flow'for 'th at portion ofzithe liquid passing through said aperturesvand'which is handled by those Iblades m the siile of the impeller adjacent the auxiliary chamber whereby to produce substantially e'quali'z edpressures on the opposite sides of the impeller.

r I tures'in its central portion in'alinenient'with the-intake:orifice. As will be understood, a r.

rln witnessthatiIclaimf'the foregoing I "James E. .vrru.

j havefhereunto.subscribed my name this 29th :day'of 1111x1929. I

Another result that obviously follows, "due I be, no'eXces'si-ve, pressures tendingito force the devloped ,pressures: on the' backside. of the limpeller will 'not exceed-those developed on 65 theff-ronton-suctibnQside. qBecaiise-ofthe' low to thebalanced pressures, is'thatthere will I liquid through thebearing, inasmuch asthe i

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