US2604050A - Centrifugal pump impeller seal ring - Google Patents

Description

FfGY-I y 22, 1952 R. A. WILSON 2,604,050

CENTRIFUGAL PUMP IMPELLER SEAL RING Filed April 27, 1948 2 SHEETS-SHEET 1 July 22, 1952 R. A. WILSON CENTRIFUGAL PUMP IMPELLER SEAL RING 2 SX-IEETS-SHEET 2 Filed April 27, 1948 l atented July 2 2, 1952 Robert A. Wilson, Cranford, N. .J., assignor to Standard Oil Development Company, a col-p0 oFFI'cEf ration of Delaware .ApplicationApl-il 27, 1948, Serial No. 23,591

- The present invention relates to means for establishing a seal between concentric members disposed for relative circular motion in spaced, substantially parallel surface relationship longithroughi i eye 3 in th imne l rhub wh chlis a Clai ms. (01. "1035111) mounted on the shaft-1i, the impeller 6 extending into the'cavity. 2 formed by the wallnportions 1 of the. impeller casing.

In the conventional structure, the hub 4 is tudinally of a common axis. More particularly, .5v provided with a sleeve member or. impeller ring the'invention relates. to such means employed to 8, and the casing with a conc-entric'casing ring provide a more eflicient seal between the suction member 9. These ring elements are fittedirigidly and discharge cavities of .a centrifugal-pump. to their respective carrier parts,.and are.ma- Specifically,an annular seal between the subchined and fitted relative to each other. to prostantially parallel surface portion of a centriful0 vide for close annular clearance between their gal'pump impeller and the casing therefore is opposed surfaces. This clearance may be in the contemplated. vicinity of A ths of an inch, andmayybe more In the conventional centrifugal pump strucor less depending upon the service in .which the ture, the seal between suction and discharge pump is employed. Even where suchclearances cavities is provided either by closely fitted rotat- .15 are employed, however, it is always intended that ing cylindrical members, orby labyrinth type acertain volume of pumped-materi'alwillbeper seals. Due .to the close clearancesfrequired, such mitted to leak through between the rings. .In seals are expensive to construct and diflicult to principle, the arrangement is not unsatisfactory, maintain. It is an object of the invention to probut inv actual use has, proved tobethesource of vide a simple mechanicalsealin which the demuch trouble. i 1 sired sealing relationship is accomplished by ac- In any high speed pump of this sort, where the tual surface contact between two parallel surshaft 5 is usually of considerable length between faces, and without special, provisionfor applied outboard bearings, a r amount of Shaft lubrication in the normal application of such play or whip is bound to exist. This condition remeans. It is a further object to provide a seal sults in momentary contacts between the closely which will compensate for normal wear and slight spaced surfaces of sealing rings 8 and 9, which irregularity in the relationshipbetween the relaproduces Wear and eventually may increasethe tive sealed surfaces. 7 j clearance to a degree that a considerable flow The invention, and its objects, may be more develops from the high pressure discharge cavity readily understood from the following description. to the low pressuresuction cavity. When this when read inconiunction with the accompanyoccurs, the pump rapidly becomes most ineffling drawings, in which: cient. Also, where the clearance is initially'too l is a verticalsectio through p t n close, or where misalignment of the shaft 5 proor. a centrifugal pump Showing 0 embodiment duces continuous contact between any portion of 9 the invention; w the rings'eal members, seizure of 'the'members e- 1 l i of i -s a n ment illuS- may occur, with consequent and extensive damtrated by F 1; age'to thepump. H a I .1 i

Fig. 3 is an enlarged vertical section through According to the present invention, the danger a ma portion of a centrifugal u p such as of leakage due to enlargement of the sealing i lu t by Showing a l of a o 40 clearance of rings 8 and 9, and of seizure due to fied form of the embodiment according to Fig. 1; improper clearance, or to misalignment 'of the and v Y j I shaft 5 may be entirely. avoided. 'The sealing F 4 is a persp ctive view of the spring elestructure provided may. be appliedto existing ment indicated in Fig. 3. pump structures, with or withoutremoval .of the Referringmore particularly. to the drawings, existing impeller and casing rings-,8 and..;9sre the numeral I designates the suction cavityof a spectively, but =in;new construction it;.is antici conventionalcentrifugal pump,and the numeral pated that, either impeller and-casingring seals, 2 the discharge cavity thereof.- The suction cav: or labyrinth seals of conventional form may be ity ;l; communicates with the discharge 1 cavity ntirely omitted, and with improved results; 5. Q J P I e1 re tsare n tliii i ime? w th centrifugal pumps, but may be obtained in any apparatus in which a seal is required between two substantially parallel, opposed surfaces disposed for relative circular motion with respect to each other.

As shown in the drawings, the seal includes annular carrier or ring member In affixed to the inner wall of the casing I concentrically with the impeller 6, and in radially spaced relation to the hub 4. This carrier ring may be secured to the casing wall in any suitable manner to provide for a, substantially fluid tight relationship. In Fig. 2 one means;is"{illustrated, %onsistingfof"ears or lugs H through which bolts [2 pass to secure the ring to the casing wall.

The carrier ring In is provided with an annu lar slotted portion or groove l:3,-into whichis in serted an annular seal ring element 14. 'Pre ferably, this seal ring is sectionaL -haVing lapped or scarfed joints as shown by dotted-lines -at"-X in Fig. l and Fig. 2. The element l4 normally will fit the slot I3 in closely spaced butireely Ieciprocal relation, and be of somewhat greaterwidth than the depth of the slot, and is resiliently mounted in the slot to prevent rotation therein. Such mounting, as shown-1 in: Fig. zl,;may be -pro. vided; bymeans; of pins I15:insertablezinicorresponding recesses I6 providedz'intheibottom.wall

of thexslotszti, and .theinneri edge of-"the ring'ld.

:In 'the embodiment according; to J'Eig; 3-3, the single -seal:-ring H],- as shown in-Fig. '1,:;is supplementedzbyzan additionalereal ring I Do, .similarato the ring l:ll,= and mounted concentrically therewith. Inth is l flayeach of the related-elemeritsend po-rtions lea, riadic; Mia, and r I-8a duplicate their-counterparts [3,114, 21:5, 01:6 ;and

. 18, :as previously. described zin conjunctionuwith the ringamember lzflainzboth characterqandfunction. f-circumstancesrequira one or more "of the iringifamem-bers i tlflsfor' .lzflaima-y be employed.

. Where morel thanione iissemployed, they/bare ramrw 12311., :the (springimeansrzbeingzneld i under partialecompression .i between lsuchnvportions contact eofiathes outer :edge toflthe aring .withlthe opposedmurface:ofitheimpellerifi.

= lnwrztherrformi of-vstbeainvention, as a illustrated-in Fig.- lsthje Springs-meanszpreyidedris aLSei-ieS of coil .tspringzelementsfi l Liltheanumber efaxelements or esp ndi g: tmth miner e spins,.l;5;a d;di

.si crim n th bottem zo eaasle tedi entiqn l3 or I3a. As shown with morezpanticularityin Fig-1J1, the member 859 :its counterpart: I Be is afsplit member withigthewends spaced.apart to provide:zqcompensationv for 1-. compression .;of-;rthe

membereinisenvice; Also; asrshowninrFignA,

spaced openings:onpassageways -;l 8baare. provided through theiring;whichgopenings';correspond in number an'd spacing tolthe respective' recessed portions-$162 0 (1. 11. 2- s. v -rnany (ii the rangements illustltedwlnd 'deserib'ed abovei the surfa'ee portidn of the impeller 6 ytfith whieh the iing' lfl' frtria'keS sealin'g Contact, ibe spec e; ma chined to provide a better add'niore uniform contact-surface, "on ets-also ,pounds, such as rbabbittr'rietal, et cetera. The determination ofthe material to'be'e'mployed will depend upon the service contemplated, the

-main consideration being that combinations not L bBfllQdfi iIl whichthe materials have an inherent tendency to score or seize, as where stainv less=steel is contactedwith stainless steel at high 20" speeds. ,Under-most conditions,- a fine grained carbon-material is'the most desirable material,

' qfiering good wearing qualities in itself, while being soft enough to wear preferentially to the contact surface of the impeller.

Although the invention has been set forth with specific referenc'ei to its-application ina centrifugaliipump, :itzisnotintended. that: it shallibe -limitedsbysuch:disclosure-ifor the purpose of-iillustration. Manyi'otheraapplications and:. embodiments ofth'e invention a-re permissiblewithinithe conceptiasi set forztha and it isintendedthatzthe be limitedlonly by the.appendediclaims.

".Wh,at is :claimed is: V 11.; Inia centrifugalipump, includinganzimpelleriandz-a casingrtherefor ansealzb'etweena.thtopposed, concentric,substantially parallel surface portions of said impeller and the casing,;co'mpris:- ing .a zpairaof carr-ierrring members, :each zafiixed in substantially =fluid tight arelati'on'to :a .wall of ssaid casingon "opposite sides 'of said impeller, cone'entriclwvith said impeller. Fand radiallyiadjaicent the periphery thereof in: each ring member an annular slotted portion opening toward an opposed surf-ace portionofvsaid impellerfa seal ring element-disposed in-said slotted portion for reciprocal movem'ent therein and extending therefronrinto-slidable engagement with said-opposed impeller surface portion, :aplurality of 43y! lindrica'llyrecessed portionsin the bottom-wall ofj 'said -c-arrier ringslotted portion, equivalent re'cessed portions in the inner-edge jdf sai d--"seal ring; the recessed portions in said car "er r-ing slotted portion and in said seal ring-- andspaeed for-opposed concentric alignnientpne with another, --resil-ient spring ;means-disposed*{ in said carrierTing slottedportionbetweerr the; bottom wall thereof and the innerjedge offs aid seal ring, and a-plurality of pin elements: freely inserted in-to' the aligned' and opposed ecessedpor tions in said seal ring andcarne rmgsl' tted portioneach pinelement extended-through'said spring means and adapted to retain-said seal ring and: spring means against substantial displacemerit/circularly oi the-earrier ring-slotted portion;

2; Apparatus according ="to claim l -inwhich said resilient spring -means comprises a plurality of individualcoil spring elements disposed-between thebottom wall of saidcarrier ring slotted portion and the inner edge-ofsaid s eal ri ngfeach of said pin elements 4 disposed so as to :extend longitudinally-through a- -coil :spring element; and substantially conce'ntric- -therewit-h, -saidspring elements perm-ally held-;- under-partial coinpres siombycontactofithe outer edgebf thefseal ring with an cpposed surfacewf said impeller: 5

3. Apparatus according to claim 1 in which said resilient spring means is an undulate annular spring element disposed in the slotted portion of said carrier ring between the inner end of said seal ring and the bottom wall of said slotted portion, a plurality of spaced passageways I 6 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Wilberforce Jan; 2, 1900 Anderson June 27, 1911 Hirth Jan. 11, 1916 Doran Sept. 9, 1919 Daugherty Aug. 2, 1932 White Oct. 18, 1932 Allen Nov. 19, 1935 Fors Dec..12, 1939 Yauch Nov. 10, 1942

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