US1918359A

US1918359A - Centrifugal impeller locking thrust eliminating means

Info

Publication number: US1918359A
Application number: US273879A
Authority: US
Inventors: Arthur R Weis
Original assignee: GEORGE E BIGELOW; PACIFIC PUMP WORKS
Current assignee: GEORGE E BIGELOW; PACIFIC PUMP WORKS
Priority date: 1928-04-30
Filing date: 1928-04-30
Publication date: 1933-07-18
Anticipated expiration: 1950-07-18

Description

Paienfea July 18,' 1933 UNITED-i STATES PATENT opl-*Flon ARTHUR R. WEIS, OF HUNTINGTON PARK,

CALIFORNIA, ASSIGNOR OF ONE-HALF TO PACIFIC PUMP WORKS, 0F HUNTINGTON PARK, CALIFORNIA, A CORPORATION OF CALIFORNIA, AND ONE-FOURTH T'O GEORGE E. BIGELOW, OF HUNTINGTON- PARK,

CALIFonNIA CENTRIFUGAL IMPELLER LOCKING THRUST ELIMINATING- MEANS Application filed A pril 30,

My invention relates to deep well turbine pumps and particularly-to the construction of the pump bowls of such pumps.

In the type of deep well turbine pumps in common use, the pump includes a pump head `loe'ated at the top of the well on the surface of the ground, a column pipe connected to and supported by the pump head, a pump ,section connected to the column .pipe 1n the impeller is materially restricted. Since the lower portion of the well, anda shaft eX- tending through, the column pipe from the pump head to the pump section.

The pump section usually comprises aplurality of pump bowls connected together end to end. There is provided a'continuous passage through the pump section connecting the impeller chambers, in each pump bowl. peller chamber is an impeller which is nonrotatably secured to the shaft. When the shaft is rotatedby the pump head the .impellers are caused to rotate, thus centrifugally impelling the well fluid upward through the continuous passage through the pump sectionlinto the column pipe and thence to the surface of the ground.

Heretofore, the impellers have usually been secured to the .impeller or pump shaft by aWoodnnlif or gib head key. .I have some times found )the keys and the key-ways in the one of which is lformed shaft and impeller hubs inaccurately formed so that the impellers when keyed lto the shaft were not -in axial alignment therewith. When'fthe impeller is thus cocked on the shaft the rotating assembly is thrown out of balance and the life of the pump is thereby shortened.

It is an object of my invention to provide a means for securing an impeller to a pump shaft so that they will be in axial alignment.

Furthermore, I have found that the cutting of key-ways in a pump' shaft many times causes warping of the shaft with a consequent whipping action during operation. This whipping action oftentimes causes crystallization and fracture of the pump, shaft.

It is correspondingly an object of my invention to provide a means for securing an e Positioned in each im- 192s.- serial No. 273,879.

In that construction of a pump section in which the impeller is secured to the pump shaft by a key, the hub of the impeller is necessarily of considerable thickness in order to provide suicient material to permit the cutting 'of a keyway. This requires that the lowerl end of the impeller hub be of a relatively large diameter so that in such constructions the central passage through the ,y diameter and extending into the central passage of the impeller, and which will thereby permit an increase in the size of the central impeller passage.

It is common practice 1n securlng an impeller to a pump shaft tol use a gib head key with its head disposed downward land supporting the impeller in proper position in the impeller chamber by engagement with the lower end of its hub. In such an assembly the head of the key projects below the hubof y the impeller --into the central passage of the impeller. f I have found that such a projection in the impeller passageway at the high irate of speed at which the impeller rotates lcauses cross-currents and disturbances which materially decrease the efficiency of the pump. It is a further object of my invention to provide a means for securing an impeller to a pump shaft which will have no irregular projections extending intothe fluid, passageway. A

` In an 'attempt to eliminate the evils consequent to the use of the gib head key, as outlined above, the impeller-s have sometimes been non-rotatably secured to the shaft by feather keys andA properlyv spaced by thin tubular sleeves surrounding the pump shaft between the ir'npellers.4 In vsuch a construction the entire assembly is forced against a arsv shoulder formed on the pump shaft about the uppermost impeller by the application of a nut to the lower end of the shaft. Be-y walls of the impeller chamber, thus completely destroying the pump.

It is a stillfurther object of my inventionv to provide a means for ysecuring an impeller to a pump shaft which will prevent axial displacement of the impeller relative to the pump shaft and which will not be rendered inoperative bythe abrasive action of the' pump fluid.

In the operation' of a centrifugal turbine pump there is exerted by the well Huid a 'greater downward force on the upper shroud of the impeller .than on the lower shroud.

This excess of pressure on the upper shroud over that on the lower shroud materially increases the axial thrust on the bearings and is therefore objectionable. i

It is an object of my invention to provide a means for attachingfan impeller to a pump shaft 'which will make the pressure on the upper shroud equal to, or nearly equal to, the pressure on the lower shroud of the impeller.

It is a still further object' of my invention to provide a means forl attaching an impeller l' to the pump shaft in which any pressure on the upper shroud in excess of the pressure- Ion the lower shroud of the impeller will make the attachment of the impeller'to the pump shaft more secure.

Itis another object of this invention to' securing two elements together, whether or not these elements comprise an impeller and a pump shaft.

lStill a further object of this invention is to provide a novel impeller construction.

Further objects and advantages will ,be made evident in the following description Vand the accompanying drawing, in which,-

Fig. 1 is a diagrammatic view illustrating the installation of a pump 'embodying my invention in a deep well. l

Fig. 2 is an enlarged fragmentary vertical sectional view illustrating the construction i of a pump section embodying my invention.

Fig. 3 is a horizontal sectional view taken on the line 3-3 of Fig. 2.

Referring tothe drawing and particularly to Fig.' 1, the numeral 11 represents a well in which a casing 12 has been extended to a A 15 so that by rotation vof the line shaft 17 the pump section 15 is caused to force well fluid from the stratum 13 upward through the column pipe 14 to the surface of the ground. I The pump section 15 includes an upper 4main bearing 19, which is attached to the lower end of the column pipe 14, and a plura lity of impeller bowls 20 connected together end to end, the uppermost impeller bowl being att-ached to the upper main bearing 19. The lowermost of the impeller bowls 20 is connected to a lower main bearing 21 which supports a' screen pipe 22 through which the well fluid enters thepump section. Each impeller bowl 20 provides an impeller chamber 23 and fluid passages 24 connecting the outer portion of each impeller chamber 23 with the central portion of the impeller chamber in the adjacent upper impeller bowl. Formed centrally through each impeller bowl 20 is a line shaft bore 25. Also centrally disposed in each impeller bowl 20 is a tapered bore 26 which, as clearly shown in Fig. 2, is

divergent downward.

Disposed in each impeller chamber 23 is an impeller 27 which provides an upper shroud 28 and a lower shroud29 connected by walls 30 to form radial passages 31. Connecting the radial passages 31 is a central impeller passage 32.

Formed on each impeller 27 and extending upwardly into the tapered bore 26 of the impeller bowl 20 is a cylindrical hub 33. As best shown in Fig. 2, there is formed in the hub 33 a central tapered bore 34 which is divergent downward. y

The impeller securing means of my invention includes a sleeve structure 34a compris` ing a sleeve 35 having a longitudinal slot 41, best shown in Fig. 3. This sleeve structure has a central cylindrical bore 36 adapted to receive the line shaft 17. At the lower end of the cylindrical bore 36 is an inwardly projccting annular shoulder 37 which is adapt-` ed to be received in an annular groove 38 in the line shaft 17. As clearly shown in Fig. 2, the sleeve 35 comprises a lower portion 39 tapered to fit in the tapered bore 34 of the impeller hub 33 and an upper externally 4threaded portion 40.

In assembling an impeller 27 upon the line lshaft 17 before the impeller bowl 20 is in position, the impeller 27 is placed loosely upon the sleeve structure 34al and the sleeve structure 34a is then moved downwardly on the line shaft 17 until the shoulder 37 engages the annular groove 38 in the ,line shaft 17 The impeller 27 is then moved downwardly on the sleeve structure 34a by the pressure exerted on the top of the impeller hub 33 by a lock-,nut 42 screwed on theexternally threaded portion of the sleeve 35.

4The slot 41 permits the contraction of the sleeve 35.v about the line shaft 17 as the impeller hub 33 is moved downwardly on the "sleeve structure 34a so that a tight frictional engagement is secured between the sleeve 35 and the line shaft 17. A tight frictional engagement is likewise secured between the sleeve 35 andthe hub 33 of the impeller' 27r by the nut 42 forcing the impeller 27 downward on the tapered portion 39 ot' the sleeve 35. It is evident that the engagement between the sleeve 35l and the impeller hub 33' 'retains the impeller 27 in axial alignment with the line shaft 17 The engagement of the shoulder 37 of the sleeve 35 with the annular groove 38 of the line'shaft 17 retains the impellers 27 in proper axial positicn upon the line shaft-17 without the use of spacing tubes. Moreover', this construction eliminates the necessity of having the huh ('33 of the impeller 27 extend into the central impeller passage 32, so that the central impeller passage is .in no way restricted by the impeller hub.

This construction likewise eliminates' they necessity of any irregular projections upon the impeller hub 33 orthe sleeve 35 in the 'central impeller passage 32, s that the well fluid in the central impeller passage is not subjected to cross-currents or disturbances.

The slotl 41, besides permitting the contraction of the lsleeve 35 about the line shaft A17 in assembling the impeller and expansion otl the sleeve 35 when removing the 'impeller also permits the well fluid that may be present between the upper shroud 28 and the tapered bore 26 of the impeller bowl' 20 easy coinmunication with the welliluid in the central impeller passage 32.'

This communication makes the pressure of the well fluid upon the iipper shroud 28 equal to lor but slightlygreater than the pressure of the well Huid uponthe lower shroud 29.

` By virtue of the downward divergence of the tapered portion 39 of the sleeve 35 and the tapered bore 34 of the impeller hub 33, any slight excess of pressure on the upper shroud 28 over that on the lower shroud 29 will increase the frictional engagementV both between the impeller hub 33 and the sleeve 35, and between'the sleeve 35l and the line shaft abrasive action.

17, so that the attachment of the impeller 27 to the line shaft 17 is rendered more secure.

It is evident that neither the engagement of the sleeve '35 .with the line shaft 17 no'r the be embodied in various other forms all com-V ing within the scopeof the claims which follow.

I claim as my invention: f 1. In a deep well turbine pump, the oombinationof: an impeller shaft having an annular groove therein; a split sleeve surrounding said shaft, the exterior of. said 4sleeve being tapered; a shoulder associated with said sleeve and adapted to t into said groove when said sleeve is contracted on said shaft; an impeller supported on said sleeve, said impeller having a bore therethrough tapered` to fit said sleeve ;and means for forcing said impeller on said sleeve to contract said sleeve on said shaft.

2. In a deep well turbine pump, the combination of: an impeller shaft having an aniiular groove therein; a split sleeve surrounding said shaft, the exterior of said Sleeve being tapered divergently downward; a shoulder associated with said sleeve and adapted to fit into said groove when said sleeve is contracted on said shaft; an impeller supported on said sleeve, said impeller having a bore therethrough tapered to t said icov sleeve; and a lock-nut threaded on said sleeve,

said lock-nut being adapted to force said im'-A vvpeller on said sleeve to contract said sleeve on said shaft and lsecure it against rotation thereon.

3. In a deep well turbine pump, the 'combination of:.a plurality of bowls, connected together vertically end to end, each bowl having an impeller chamber and passageways connecting the outer portion of said iin- Vpeller chamber to the central portion of the' adjacent upper impeller chamber; a plurality of impellers, one of which is disposed in each impeller chamber; a shaft extending through said impellers; a hub portion eX tending upward from the upper shroud of each impeller, said hub portion having a bore tapered' divergently downward; a sleevel disposed around saidshaft in each of .said hub portions, the exterior of said sleeve being tapered to fit the tapered bore of said hub portions, said sleeve being split to facilitate the contraction of said sleeve and provide a together vertically end to end, each bowl having an impeller chamber and passageways connecting the outer portion ofsaid impeller chamber to thecentral portion of the adjacent upper impeller chamber; a plurality of impellers, one of which is disposed in each impeller chamber; a shaft extending through said impellers, said shaft having an annular groove for each impeller bowl; a hub portion extending upward-from the upper shroud of each impeller, said hub portion having a bore tapered divergently downward.; a sleeve disposed around said shaft in each of said hub portions, the exterior of said sleeve being tapered to fit the tapered bore of said hub portions, there being a slot formed in said sleeve'to facilitate the contraction lof said sleeve .and provide a fluid passageway around the upper shroud of each yof said impellers, each of said sleeves having a shoulder adapted to lit into one of said grooves when said lsleeve isl contracted.l on said shaft to secure` sald sleeve against axial movement on said shaft; and a lock-nut adapted to be threaded upon said sleeve to force said impeller downward on said sleeve to securesaid impeller against movement relative to said sleeve and to contract said sleeve j on sald shaft toseeure it against movement relative to said shaftj- 5.. In combinatid; a shaft; an impeller havlnga tapered bore therein into which said extends, the walls of said bore diverglingvv 1n r the direction of action of a thrust transmitted tosaid impeller and tending to move said impeller along said shaft; a split sleeve structure having an external sul face tapered toi-correspond to said tapered bore; and meansforpreventing axial movement between said sleeve and said shaft whereby the thrust exerted on said impeller moves said sleeve into said bore whereby sa'id sleeve 1s compressed around the periphery of said shaft.

6. In combination in a deep well turbine pump: a substantially vertical impeller shaft; an impeller having a tapered boreinto which said shaft extends, the walls. of said bore diverging downward, said impeller being subjected to a downward hydraulic thrust when in operation; a sleeve structure tapered to lit said' bore and extending there- `in; and means adjustable from the top of said vthe smaller end of said tapered bore opening on the top of Vsaid impeller and the larger end of said tapered bore opening on said central passage, said shaft extending into said tapered bore; a sleeve structure tapered to fit said bore and providing a lower wall contiguous to the walls of said central passage; and means at the top of said impeller for drawing said sleeve structure into said tapered bore to contract said sleeve structure on said shaft.

8. In a turbine pump, the combination of: a shaft; an impeller providing acentral impeller passage through which the pumped fluid passes, said pumped fluid exerting ahydraulic thrust on said impeller; and a clamping means for securing said impeller to said shaft, said clamping means defining a passage communicating between said central impel ler passage and a space immediately above said limpeller whereby saidhydraulic thrust is decreased. v

9. A combination as defined in claim 8 in which said clamping means comprises a sleeve closely surrounding said shaft and split longitudinally whereby the space formed by said split defines said passage and permits contraction of said sleeve around said shaft, the external surface of said sleeve being tapered, said impeller providing a bore correspondingly tapered whereby a movement of said impeller along saidl sleeve contracts saidsleev around said shaft.

10. In combination: a shaft providing an annular groove cut inward from the surface thereof; a split sleeve formed of a single split member contractible to come into surface contact with said surface of said shaft and providing'an annular shoulder extending into said annular groove, whereby when said sleeve is contracted said shoulder snugly fits into said annular groove to position said f sleeve relative to said shaft but when. said sleeve is expanded said. annular shoulder moves from said annular groove topermit said sleeve to slide along saidA shaft, the eX- terior of said sleeve being tapered;,a member having a bore tapered to correspond to the taper of said sleeve and movable into a position around said sleeverafter said sleeve is positioned relative to said shaft to effect inter-engagement between said shoulder and said annular groove; and means'for moving said member along 'said sleeve to move said sleeve into vcontracted position.

ARTHUR R.y wars..