US2265834A - Pump lubrication - Google Patents

Description

Dec. 9, 1941. G. H. GARRAWAY PUMP LUBRICAT'ION Filed Dec.- 2l, 1939 4 Asneeuw-s'lnaet 1 Dec. 9, 1941.

G. H. GARAWAY PUMP LUBRIcATIoN Fild'nec. 21, 19:59 4 sheets-sheet 2` A Dec. 9, 1941.

G. H. GARRAWAY PUMP LUBRICATION 4 Sheets-Sheet 5 Filed Dec. 2,1, 1959 Dec. 9, 1941. GTH. GARRAwAY PUMP LUBRICATION Filed Dec. 21, 1939 Y 4 Sheets-Sheet 4 Patented Dec. 9, -1941 UNI-TED STATES, PA'rl-:NT ol-Fl rmunmcsnon George n. Gsmway.' Noren mamada.' N.

.1.. vairsignor to Standardoil Development Company, a corporation or Delaware Application December, zi, 193s. serial No. siam s claims. (ci. ros-111) The present invention relates to a method and means for lubricating multi-stage centrifugal pumps. More particularlyfdt -relates kto such a method and means' adapted toprovide positive lubrication for pumps having nointernal bear- 'ings,.or whichmay be used for the handling et hot or normally gaseous iluids. A s pecii'ic em-v bodimentoi the invention contemplates structure` ands-a mode of operation in whichthe iluid being pumped may be used to supply thepositive lubrication required, or in which lubricant from a separate source alone or incooperation'with the pumped huid may be utilized.

The conventional multi-stage centrifugal'pump is ordinarily designed to utilize the' lubrication eect of inter-stage leakage to `protect: internal wearing surfaces from dangerous irictional oo ntact. AThis eilect, when pumping light fluidais ot the nature oi' a iloating or cooling' action rather than true lubrication, and while it may Y.

be eflective so long as-suction is maintained in all stages, if suction is lost, there is no residualV lubricant illm between -the wearing surfaces to Trovide the protection required., With the loss of theiioating actionoi intra-stage and interstage leakage,.the wearingsurraces rapidly deteriorate and seize under 'the heat of frictional contact at the high speedsct'V pump operation.A

By means'of the present invention. a positive floating or lubrication eiect is maintained at all times between the principalwearing surfaces.

iluid forced between the wearing' surfaces.

The invention and its objects may be .fully with a plurality ,of chambers., 0a,

Ineach vchamber the pressure upon the uuidwhether or not the .pump maintains its suctiongjf in the manner intended. The oating eiie'ctof intra-stage and inter-#stage leakage is comple-- mented or supplemented by a positive supply of` 35 understood from the'iollowing speciiication when it is read in conjunction drawings, in which Fig. 1 is a longitudinal section through one.

form of. multi-stage centrifugal pump;

with the accompanying Fig. Z-is an enlarged sectional view showing' twostages oi' compression in' the pump. illustrated in Fig. 1 and the elements involved therein;

Fig.. 3 is a longitudinal. section through another form of multi-stage centrifugal pump of the: dii'- raser. type:

Fig. 4 is an enlarged sectional. view showing two stages of compression in the pump illustrated in Fig. 8 and the elements involved therein; and- Fig. 5 is a diagrammatic showing or a lubri# cation system according to the presentinvention. Referring to the drawings and particularly to .chambers Ie' 45 connecting line, not shown.

Figs..i and 2,"there isshown a multi-stage een;

triiugal pump in which the principalparts designated are the pump barrel i, having asuction nozzle 2 'and a discharge nozzlejl; a two-part volute' impeiler casing l, of which one-halt is .to'sef'forth the. nature oi the present invention .a bracket Ic'supporting a bearing, not shown, for

the other end of the shaft.l

The volute impellercasingll is .cast or formed if, la, and Ih', connected by the passages-1, 1a, 1b, 1c, 1d, le, 'if and lo. Fluid flow through the` respective chambers and passages is." accomplished, in operation, from chamber i through a" connecting line, not shown, `and passage 'I to chamber ta.- Thence now continues passage 'la to .chamber Ib, and vso on -to chamber td. From chamber Bd, now continues through a and passage ld to chamber te. Thence now continues through passage 'ie to chambertf and soon to chamber Chi 'whichenters originally by way o! the .suction .nozzle-2 and. chamber l,- isfraised abovethat of 'the.-preceding,.chanber, andthe fluid under its 1pump pressure is discharged'trom chamber th into' the substantially annular space [between the volute impeller vcasing and the pump 'barreLwhence it discharges through the .clusive,"compri sin gthe first vseries providing the .second stages of compression.' The "to inf-inclusive, comprise the second .series providin'gthesixth to ninth stages of comlv pression. 'Each chamber and series group, is spacelieiroirifanother'bilfnleans ofj-ftlie rib portions' la" between .a passage'. and' a chamber, and theV 'rib 4portions '4b v*between a chamber' and a `passage.-'I'l 1echamber l is spaced-fromme. passage ld by an lenlarged ribl portion {awhile-the' two seriesV groups -a're spaced by a rib"portion' and 8h. Provision is 4in/ade in each -oi the rib 'portions 4a 'for receiving a case wear-ring Ia,

lb, lc, td, te,

ld between the chambers Id and in each of the rib portions Ib, provision is made to receive a stage piece Ib. Likewise, the rib portions 4c and 4d are provided to. receive stage pieces Ic and Id respectively. In addition,

the chamber I is formed with shouldered por- 5 tions vadapted to receive case wear-rings I. 'Ihese case wear-rings and stage pieces mentioned, along with other shaft elements, are suitably assembled on the shaft before enclosure in the volute casing halves. f i

second to ninth stagechambers inclusive.. Iml5 peller wear-rings ll are disposed between the impeller Il and case -wear-rings I, and impeller Y wear-rings I ia between the impellers Illa and case wear-rings Ia. Series stage wear-rings I2 are disposed between the shaft and seriesI stage 20 pieces Ic and Id, while stage wear-rings i2a are disposed between stage pieces Ib and the impellers IIa.

In the conventional structure thus far set forth, frictionai contact may be made between case wear-rings I and Ia and impeller wearrings Il and lia, between stage pieces 5b and stage wear-rings |2a; and also between series stage pieces Ic and Id, and series'stage wearrings I2. 'I'hese points of possible friction in the 30 conventional structure are intended to be lubricated by intra-stage and inter-stage circulation or leakage. Such lubrication, however, isonly eiective when suction is maintained.

throughout the system. When suction is lost in any stage, the lubrication or iioating and cool' ing eii'ects of the pumped fluid often fail to prevent over-heating and seizure of the parts in frictional contact. Also, when working with certain types oi' materials it may be desirable to 40 supplement the lubrication effect of. the pumped fluid by a lubricant supplied under positive pres; sure from outside the pump. I

To the structure illustrated in Figs.- 1 and 2,

it is now proposed to add a positive lubrication system. The system specifically shown is composed of a series of passages I3 drilled in the volute case 4 through rib portions 4a to 4d inclusive, communicating by way of extensions thereof through the respective case wear-rings,

and stage pieces. At the inner end of the impeller casing, the passages extend through the walls of the chamber 6 and case wear-rings I. In each passage I3 or the connecting feed pipes |4, it is desirable to have a `check valve lla to prevent Ainter-stage pressure loss. These passages are extended by means of the feed pipes I4 to an inter-connecting distributing line I5 which in turn is supplied by means of the feed line I5..

The lubricant material supplied through theses() lines may be drawn fromthe discharge line of the pump under pump pressure, or may be derived from a separate source as required.

Another conventional form oi' multi-stage centrifugal pump is illustrated in Figs. 3 and 4, in 66 which the principal parts are designated as pump barrel 2|, supporting .heads 22 and 2.3,4 in which are included the suction nozzle 22a and discharge nozzle 23a respectively; and impeller easing 24 made up ot channel rings 24a and diii'user rings 70 2lb, and an impeller shaft 25.

'The head 22 carries a-bracket 22h supporting a bearing, not shown, for one end of the shaft 25, while thev head 23 carries a bracket 22h supporting a bearing for the other end of the shaft. .75

aaeasaa The impeller casing 24, as formed by the channel rings 24a. and diiiuser rings 2lb, fits in "the pump barrel in substantially iluid-tight relation to the barrel and to each other, and forms a plurality o f chambers 264,251, 2Ic, 2Id, 26e, 25],

26g, and 28h; and a plurality of passages 21a,

-ring provides a passage 21 communicating with an annular space 2I in the head 23, opening through the discharge nozzle 23a. Fluid ilow progresses in stages through the series of chambers and passages from one end of the pump to the other, the fluid pressure being raised from one stage to another. y

'I'he conformation of the channel rings 24a is such as to provide a plurality of stepwise rib portions 24e and 24d. The rib portions Nc are adapted to receive case wear-rings 29a, while the rib portions 24d receive stage pieces or channel ring bushings 29h. A head wear-ring 2I is provided in inner shaft opening in head 22.

The shaft 25 carries on that portion disposed within the barrel a series of impellers II and IIa.

The impeller II providing for the nrst stage of compression, communicates with the interior of head v22 and discharges into chamberl ZI. The remaining impellers provide for the successive stage of compression, with the ninth or outermost impeller discharging into chamber 2Ih and outward therefrom through the passage 21. ' I'he impellers 30 and 30a may be in frictional contact with the head wear-ring 2s and case wear-rings 29a respectively, through impeller wear-rings Il and Ila. The proper spacing of the impellers I0 and Illa on shaft 25 is accomplished by means of the sleeve members 32 with which the stage pieces or channel ring bushings 29h maybe in i'rictional contact.

As in the form of multi-stage pump illustrated" by Figs. 1 and 2, the eiiect of friction between rotating and iixed parts inl contact is intended to be alleviated in the pump illustrated by Figs. 3 and 4, by means of intra-stage circulation or inter-stage leakage. In this form of apparatus, the lubricating vor floating effect is no more eilicient on loss ofg'suction and it is proposed to add a y positive lubrication system thereto.

In the structure shown by Figs. 3 and 4, ex-

cess pressure on the packing at the discharge end of the pump and excessive axial 'hydraulic thrust is prevented by a generally conventional arrangement. Bushing 4I is secured in substantially fluid-tight relation to the head 2l by means of bolts Il. The balancing drum 42 having a flanged head portion 42 isheld in substantially fluid-tight Arelation to the shaft 25 by means 0f lock nut 43 and the tapered sleeve Il. The balancing drum 42 rotates in the sleeve III with extremely close clearance, leakage therebetween being returned to the suction end of the pump by means not shown.

In order to provide positive lubrication of the inner pump parts which are in frictional oontact as set forth above, a system, similar in con. cept to that shown in The system speciiically shown, is composed of a series of passages I3 drilled through the rib portions 24e communicating. by way of extensions thereof,through the respective case wear-rings 29a and with a distributing line or drilled pase aIlhwlfiich in turnv is supplied by the feed Figs. 1 and 2, lis'applied.,

Due to the construction of the/pump lubricant. In hot oil service,

shown, however,.it is not possible to lubricate the points of contact between channel ring bushings 29b and the sleeve members 32 by means of' dei-cutting the longitudinal shaft keyway by which the impellers and sleeves are keyed to the shaft for rotation therewith. From the distributing passage 35h, passages 33a are drilled'in the shaft 25 and through sleeves 32 whereby the contact between sleeves 32 and channel ring bushings 29h may be lubricated. Contact between the head wear-ring 29 and impeller wearring 3l is lubricated by means of an angular pas-4 sage 31 drilled in the inner portion of head 22, and communicating with the distributing passage 33 extending through the impeller casing 24.

Fig. provides diagrammatic illustration of a lubrication system according to the invention. As shown, the system is composed of a multistage centrifugal pump 5I having suction and discharge nozzles 52 and 53, connected respectively to a feed line 5l and a discharge line 55, the pump 5I being provided with internal lubrication distributing lines and passages in the manner shown in Figs. 1 to .4 inclusive. Connected to the internal llinesand passages a feed line 55 extends outwardly from the pump 5| toward a source of supply, such as bleed-off line 51 from the discharge line 55. Preferably the lines 55 and 5'lk are connected through a multipms valve 58 which is also connected by line 59 through pump 60 and line 6|, with a separate supply source for lubricant material, such as tank 62. Valves 55a, 51a, 55a and Gla may be provided in the respective lines.

In the preferredform, with valves 56a, 51a, 59a

and Sla. open, and the multi-pass valve 58 affording communication between lines 55 and 51, a small amount-of the iiuid being handled by pump 5l will be circulated by the flow ofthe material being handled may be again circulated and will ush from the lines and bearings surfaces all traces of the auxiliary this action prevents coking and plugging of the internal lubrication lines and psages.

It is also preferable that operation of the sys-, tem be subject to automatic control, and for that purpose, controls as shown may be provided. A flow meter 63 or another suitable device may be disposed in the discharge line 55, and by electric connection, asindicated at 53a, with a pump control mechanism 54 on pump 50 and a'valve way of lines 5l and 56,'. .through the inner lubricant lines and passages plurality of conduits in said pump,

control mechanism 55 on valve 58, the meter may be made to actuate the pump and 'valve so as to maintain lubrication of .the pump in the manner set forth above.

It is contemplated that automatic operation of the lubrication system may be' accomplished-also by means of a now meter or similar device disposed inthe suction `or feed line 54, Such an arrangement is indicated, the iiow meter'device V being designated by the numeral 56, electrically connected to the line 53a by a line 56a. Furthermore, in certain services, such as ,in the pumping of light or normally gaseous materials,`

it may be found desirable to use the external source of lubricant to the exclusion of the recirculation of a portion o f the pump discharge.

Obviously, these and other changes may be made in the system as set forth withoutdeparting from the inventive concept. Therefore, it is' not intended that the invention shall be con-V sidered as limited by any disclosure of the specification or drawings which have been made for the express purpose of illustration. It is intended that the sc ope oi this invention shall be limited only'by the appended claims.

I claim:

1. In combination with a multi-stage centrifugal pump, a lubrication system comprising a plurality of conduits in said pump opening to the inter-stage and intra-stage wearing surfaces between rotating and non-rotating elements of said pump, a conduit system for a liquid lubricating material, communicating with said inner conduits, means for delivering said material to the system under positive pressure, and a means for controlling the supply of said material to the system, according to the ow of .uid through said Dump-k 2., A system according to claiml in which the means for controlling the supply of said material to the system is a iiuid meter-in the discharge line of the pump adapted to activate the means for delivering said material to the system.

3. A system according to claim 1 in which the means for controlling the supply of said material to the system is a fluid meter in the suction line of the pump, adapted to actuate the means for delivering said material to the system.

4. In combination with a multi-stage centrifugl pump, a lubrication system comprising a plurality of conduits in said pump opening to the inter-stage and intra-stage wearing surfaces between rotating and non-rotating elements of said pump, a reservoir for a liquid lubricant disposed externally of said pump. connecting conduit means communicating withsaid'inner con-- duits and the reservoir, means for supplying said liquid'material to the inner conduits under positive pressure, and an activator for said means actuated by the flow of liquid through said pump.

5. In combinationwith a multi-stage centrifugal pump, a lubrication system comprising a opening to the inter-stage and intra-stage wearing surfaces between rotating andv non-rotating elements of said pump, a reservoir for a liquid lubricant disposed externally of said pump, connecting conduit means communicating with said inner conduits and the reservoir, means for supplying said liquid material to the connecting means under positive pressure, a connection between the dis- 4 'einem mummy activated, by :ne suv n: imum through said pump. 1 V '6. .In combination with a multi-stage centrifua1 pump. a lubrication system comprising a plurality of conduits within the pump opening to the inter-stage and intra-stage wearinz surfaces between rotating and non-rotating elements of said pump, means communicatinfwith said inner the discharge v said meter.

' Gnomz n. Gsmwar.

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