GB Patent 556853 - Improvements in and relating to centrifugal pumps

Claims

perfortne(l I declare thllat wlqat I claim

is: 130 Ran ORIGINAL 53)56,853 1 A centrifugal pump of the single imnpeller andl single end entry type wherein that side -wall of the pump casing' through which the impeller shaft enters is provided with at central opening which is of an external diameter sufficient to enable a separately formed stator to be inserted into or withdrawn from the interior of the easing by an axial movement of the stator through said opening and the stator on the side thereof adjacent said opening.

is provided also with a central openiag through which the impeller is movable axially for the purposes of insertion or removal as required.

2. A centrifugal pump according to Claim 1 wherein the central portion of the opening in the said side wall of the casing is normally closed by a detachable ring plate mounted upon the impeller shaft.

3 A centrifugal pump according to Claim 2 wherein the external diameter of the ring plate is less than that for the said opening so that an annular space is formed between the outer l)eriphery of the ring and the opening which space is nornially closed by a corresponding wall portion of ihe stator.

4 A centrifugal pump according to Claim 3 wherein the outer periphery of the stator is extended to lie on the outside of the pump casing.

A centrifugal pump according to Claim 1 wherein the one side wall of the pump casing or delivery ring is permanently closed and the opposite side wall thereof is formed with a central removable ring plate the outer peripheral portion of which is extended to overlap the outer peripheral portion of the stator.

6 A centrifugal pump as claimed in any of the Claims 1 to 5 wherein the stator is formedi in one piece or is provided in more than ote piece to facilitate the foruildry work.

A centrifui;al pump as claimed in Claim 6 whl Qerein the stator is formed in two separate pieces joined together in a plane perpendicular to the longitudinal axis of the suction duct, the one piece including that side wall of the sfator which is disposed within the delivery ring to lie adjacent to the opening in the side wall of the casing through which the stator is movable for insertion or removal and the other piece including the other side wall of the stator, which wall thereof is disposed within the delivery ring to be exposed to the effect of the delivery pressure obtaining therein.

S A centrifugal pump as claimed in any of the Claims 1 to 7 wherein that side wall of the stator which is disposed within the discharge ring to lie adjacent to the permanently closed side wall of the casing is provided with a central huh portion which projects axially outwards towards the suction duct and has a sliding fit upon the inner end portion of the latter.

9 A centrifugal pump as claimed in Claim S wherein the inner end of the suction duct is spigoted and the said huh portion of the stator has a sliding fit upon the spigoted end of the suction duct.

A centrifugal pump as claimed in Claim 8 wherein the inner end of the suction duct is formed with a recess or rabbet with which the said hub portion of the stator slidably engages.

11 A centrifugal pump of the type referred to substantially as described herein and; as illustrated in the accompanying drawings.

Dated this 31st day of December, 1942.

MARKS & CLERK Leamington Spa: Printed for His Majesty's Stationery Office, by the Courier Press -1943 4 =i

Description

PATENT SPECIFICATION

Application Date: Nov II, 1942 No 15955/42 556,553 Complete Specification Left: Jan 12, 1943 B'M 1

Complete Specification Accepted: Oct25, leer Id'

PROVISIONAL SPECIFICATION

FEB 1946 Improvements in and relating to Centrifugal Pumps I, WA XLLM J E REST W'YATT MILLIXNGFON, of 28, \Victoria Street, Londlon, S.W l, a British subject, do hereby declare the nature of this invention to be as follows:This invention relates to centrifugal pulmps of the single impeller and single entry type and has for its object ta provide an improved construction of such pumps which provides a ready and simple means of effecting adjustments to accommodate impeller changes within certain -working limits.

The invention consists in a pump of the type referred to wherein a staetor surrounding the impeller is separately formed and insertable within the pump easing or delivery ring from one side of the latter such that the stator is readily accessible or can be removed to permit the required adjustments to be effected.

The statoi (which may be provided with the usual outwardly curved peripheral sections to provide a volute or guide passages) may be formed in one piece to have satisfactory sealing engagement with the pump casing, or the stator mar be provided in more than one piece and(l may be formed, for example, in two separate pieces joined, together in a plane perpendicular to the longitudinal axis of the suction duct, whereby the foundry work is facilitated.

The seating engagement afforded is such 36 as will maintain the separately formed stator sealed with respect to both sides of the casing.

In carrying the invention into effect in one convenient manner, a single impeller and single entry pump is provided comprising a easing having a central suction duct delivering into a discharge ring surrounding the impeller at the deliver T end of the suction duct and having a delivery outlet at a suitable point around its outer periphery, the said suction duct projecting axially from the centre of one side of ihe ring casing and the latter on its opposite side, beyond the outer periphery of the impeller, being forced with an annular opening through which the outer periphery of one side wall of a separately formed stator ring projects to have sealing lPrice 1/-l engagem Llent with an outer ring surface of the easing surrounding said annular open 55 ing, the latter being completely closed by this side wall of the stator and the inner periphery of the latter on such side thereof being conveniently formed with a ring surface perpendicular to the longitudinal 60 axis of the suction duct and having abutting engagement with a rabbet on t lhe inner surface of the wall of the casing adjacent the inner periphery of the said annular opening The said inner abutting 65 ring surface on the stator may be in a plane set inwards or outwards somewhat from the parallel plane in which the said outer sealing ring surface oni the stator is locafed and the inner periphery of the 7 U annular opening is conveniently provided upon a separate removable ring plate having a central hub projecting axially outwards therefrom and conveniently forming a bearing and/or stuffing box for the 76 impeller shaft, the impeller being either of the open or closed type, as required.

The opposite side wall of the stator is arranged to be located within the discharge ring and is formed with a central 4) hub portion which projects axially outwards towards the sufction duct and-has a sliding fit over the inner end thereof either by the outer end portion of the hub being fitted over the outer surface of a 85 spigot end of the duct or by the latter being formed at its inner end with a recess or rabbet upon the cylindrical longitudinal surface of which the corresponding surface of a rabbet at the outer end of the hub 90 slides, there being a sealing ring provided if necessary in the rabbet on the hub to have sealing engagement therewith and with the adjacent ring surface of the sid:e of the pump casing In the alternative 95 construction described, a sealing ring may also be provided around the spigoted inner end of the suction duct to afford a seal between the opposed ring surfaces of the stator hub and easing on opposite 10 (l sides of the sealing ring.

The stator is provided around its periphery with outwardly curved plate seetions forming a volute or guide passage for the flow of the pumping medium and 105 the stator can be formed in one or in 1.

) 5.56,853 separate pieces For instance, and to facilitate the foundry work, the internal wall of the stator may be in the form of a simple ring having a central radially projecting hub extendino' to the outlet end of the suction duct anc Y pinned around its outer periphery to the edge of a radial flange formed on the outer periphery of a separate ring forming the other side wall of the stator and which ring closes she annular opening in the pump casing and has an outer peripheral portion or flange which extends in a plane perpendicular to the longitudinal axis of the suction duct and engages with the outside ring surface on the delivery ring of the pump casing.

Thus, the stator may be made in two parts joined together in a plane perpendicular to the longitudinal axis of the suction duct and prevented from rotating relatively to one another, which rotation, however, is resisted during operation of the pump by the delivery pressure built up within the delivery ring automatically providing an excess' loading effort which operates 25 against the inner side wall of the stator and tends to mnailintain the stator in sealing contact with the p)ump easing to prevent unwanted leakage fronm the delivery side thereof 30 In a modification of the invention the outer periphery of the said ring plate is extended to overlap the outer peripheral poriion of the stator, the pump casing on this side thereof beina' formed with a cen 85 tral opening in which the ring plate is contained and the said outer peripheral portion of the stator being made to project outside the casing and engage with the outer sur'face of the periphery of the said 40 central opening therein.

Dated this 11th day of N-oveiiber 1942.

MARKS & CLERK COMPLETE SPECIFICATION

Improvements in and relating to Centrifugal Pumps I, 1 WILLIT Am ERNEST WYATT MILLINGTON, of 28, Victoria Street, London, S.W 1, a British subject, do hereby dedlare the nature of this invention and in what manner the same is to be performed, to be particularly described& and ascertained in and by the following statement:51 This invention relates to centrifugal pumps of the single impeller and single end entry type and has for its object ta provide an improved construction of such pumps which provides a ready and simple means of effecting adjustments to accommodate impeller changes within certain working limits By "end entry" is meant that type of pump wherein the suction inlet duct for the entry of the fluid is on the side of the pump casing opposite that through which the impeller shaft enters.

The invention consists in a centrifugal pump of the single impeller and single end 6 entry type wherein that side wall of the pump casing through which the impeller shaft enters is provided with a central opening which is of an external diameter sufficient to enable a separately formed stator to be inserted into or withdrawn from the interior of the casing by an axial movement of the stator through said opening and the stator on the side thereof adjacent said 'opening is provided alsa with 76 a central opening through which the impeller is movable axiallyv for the purposes of insertion o rremoval as required.

The stator (which may be provided with the usuail oum ardlv curved peripheral sections to provide a volute or guide pass 80 ages) may be formed in one piece to have satisfactory sealing engagement with the pump casing, or the stator may be provided in more than one piece and may le formed, for example in' two separate 85 pieces joined together in a plane perpendicular to the longitudinal axis of the sue'tion duct, whereby the foundry work is facilitated.

The sealing engagement afforded is such 90 as will maintain the separately formed stator sealed with respect to both sides of the casing.

In the accompanying draw-ings:Figure 1 is a vertical sectional view 9,5 of a centrifugal pump in accordance with the invention showing in the top half thereof one construction and arrangement of stator and impeller and in the bottom half another construction and arrange 100 ment thereof, Figure 2 is a section on the line A-A of Figure 1, Figure 3 is a half vertical section similar to the top half of Fioure 1 but 105 shiowing a two-part stator eonstruction, and Figure 4 is a half vertical section of anotlher modification.

In carrying the invention into effect in 110 one convenient manner as illustrated in the drawings wherein like parts are given tlhe same references and referring first to (,5853 Figitres I anld 2, a,inglc imlpeller and single eltr 1)u 1111111 is provided coaprisin g a easillng I hlaving a cent'al suction duet 2 deliveriung) into a discharge rillng 3 surrounding tile impeller at the delivelry end of thle suctioi duet and havilng a delivery outlet 4 at a suitable point arrolli(l its outeri perilhlery, the said suction (lduct projec'ing' axially firom the centre of the side la of the ring casing andl thle latter onl its opposite sidle lb, bevond the outer periphery of the illmpl)elle, beilng formed with an annular opening 5 through which the outer peri'phery (a o I 6 One side wall Gb of a separately formed stator ring' 6 projects to have sealing' engageent with an outer ring surface 7 of the casili' surrioundil,g said annular opening, this latter being coipl)letely closed by this side wall 6 b of the stator and the inner periphery of the latter onl such side tlhereof being colnveniently formed with a ring surface Ge perpendicular to the longitudinal axis of the suction duct and having abutting engagemenit with ai rabbet 8 on the inner surface of the wall of a removable ring plate 9 The said inner abutting rillg surface 6 c on the stator may be in a plane set inwards or outwards somewhat from the parallel plane in which the saitl outer sealing rin#' surface 7 onl the stator is located ad tihe inner periphery of the annular opening is conveniently iprovided upon the separate removable ring plate 9 which has a central hub 1 ( O projeeting axially outwards therefrom and conveniently forming a bearing' and(l/ or stuffing box for the impeller shaft 11, the imnpeller 12 being either of the optn, as shownl in the top half of Figure 1, or of the closed type, as shown in the bottom half of Figure 1 The opposite side wall Gd of the stator is arranged to be located within the dischar'ge ring 3 and is formed with a cen tral hub portion 6 e w Thich projects axially outwards towards the suction duct 2 an(l has a sliding fit over the inner end 2 a.

thereof either, as shown in the top half of Figure 1, by the outer end portion 61 of the hub being fitted over the outer surface of the spigot end 2 a of the duct or, as shown in the bottom half of Figu-re 1.

by the duct being formed at its inner end with a recess or rabbet 13 upon the cylindrical longitudinal surface 13 a, of which the corresponding face 14 a of a rabbet 14 at the outer end of the hub slides, there b)eingo a sealing ring'15 provided if necessary in the rabbet on the hub to have sealing eng'agement therewith and witch thle adjacent ring surface 16 of the side of thle punip casing In the alternative construction illustrated in the top half of Figure 1 a sealing ring 16 a may also be plrovi(ded 1 al:lll lhe sp)igoted(l inilner e Cld f thle suction duct to alfford a seaul lbetseenl the opl)posedl rill, urfae of the stator hub an Ld casing) ol op)posite sides of the sealilng ring 7 The stator is providedl around it, periphery with outwardly curved plate seetions Gg forming volutes or guide passa'e for the flow of the pumpingo mediunm aind the stator can be formed in one or in 75 separate pieces For instance, as illustrated iu Figure 3, and to facilitate thle foundry work, the internal wall Gd of the stator may be in the form of a simplle ring hlaving a central radially projecting hub 8 (J (e extending to the outlet end(l of tlhe suction duct and: pinned around its outer lperiplhery 6 h to the edge of a radial flangoe Gi formed on the outer periphery of a sep)ara-e rinng Gj forming' the other side wall of the 85 stator and which ring closes the alnular opl)ellillg o inl thle pumllp casingo and lhas an outer l)eripheral portion or flainge Ga, which extends in a plane perpendicular to tile longitudinal axis of the suction,duiet and 90 engages with the outside ring surface 7 onl the delivery ring 3 of thle pump casinlg.

Thus, the stator may be made in two parts joined together illn a lplane perpendicular to the longitudinal axis of the suction duct 95 auld prevented from rotating relatively to one another, which rotation however, is resisted during operation of the punllp by the delivery pressure built up within the telivery ring' automatically providing an 100 excess loading effort iwhich operates against the inner side wall 6 d 1 of the stator and tends to maintain the lparts of the stator in sealing' contact with one another to prevent unwanted lealkage from the 105 delivery side thereof If desired, the stator may be provided around its periphlery with one curved plate section forming a single volute or if separate plate seelions are employed these may be of any 110 convenient number and form.

In a modification of the invention, as illustrated in Figure 4, the outer periphery 9 a of said ring plate 9 is extended to overlap the outer peripheral portion 6 a of the 115 stator, the pump casing on this side thereof being formed with a central opening, 5 a in which the ring plate is contained and the said' outer peripheral portion'6 a of the stator being made to project outside tlhe 120 casing and engage with the outer ring surfacee 5 b of the periphery of the said central opening therein Releasable screw bolts 17 may be provided to secure the assembly in position on the pump casing 125 Having now particularly described and ascertained the nature of umy said invention and in what manner thle same is to be