US1849217A - Pump - Google Patents

Description

March 15, 1932. V'M. Di. AISENSTEIN 9,

- PUMP Filed Jan. 4, 1930 s Sheets-Sheet 1 v INVENTOR M/CHAEL .0. fixsfn srf/fl BY 2 A'ITORNEYY 7 5 Shwts-Sheet 2 III INVENTOR w. m N "a n M 03m A v A 5 W m M March 15, 1932. M. D. AISENSTEIN PUMP Filed Jan. 4, 1930 Elli! March 15, 1932. A|$EN$TE|N 1,849,217

PUMP Filed Jan. 4, 1930 3 Sheets-Sheet 3 INVENTOR Mm D fi/ENSTE/N MICHAEL D. AISENSTEIN, OF BERKELEY, CALIFORNIA, ASSIGHOB 1'0 UNITED IRON Patented Mar. 15, 1932 UNITED STATES PATENT OFFICE WORKS, OF OAKLAND, CALIFORNIA, A CORPORATION OF CALIFORNIA run .ppncatlon filed January 4, 1930. Serial lio. 418,584.

This invention relates to that class of pumps commonly known as multi-stage centrifugal pumps that are provided with an inner casing in'which the pump impellers are revolubly mounted and an outer casing for completely enclosing the inner casing during the operation of the pump.

he invention more especially relates to a pump having an inner and outer casing that are particularly constructed to be used when pumping hot oils against high pressures.

As that class of pumps are generally of large capacity, itis desirable to build the outer casing in the form of a circular housing with one or both ends open and to provide heads or end covers for closing the said ends and enclosing the inner casing that is mounted therein. This construction is necessary, due to the fact that the outer casing being very large and subject to heavy internal fluid pressures, it is practically impossible to seal the horizontal joints in a casing of the horizontal split type. When that type of pump, having an outer casing with end covers on. is pumping against high pressures, a tremendous pressure is exerted against the discharge end cover of the said outer casing, with the result that the said cover and bolts are subjected to excessive strains, and much serious danger is involved should the cover blow off or burst and thus permit the hot oil to escape out of the pump and into the atmosphere.

It is therefore one of the objects of the present invention to improve pumps having an inner casing and an outer casing of the type described, by forming the parts in such a manner as to provide a separate chamber between the inner casing and the end cover ternal pressure of the fluid against the end cover.

Another object of the invention is to provide a flange around the discharge pressure end of the inner casing and to fasten said flange on the discharge pressure end of the outer casing to substantially hold the inner casing in the outer casin Another object of the invention is to improve the method of balancing the fluid pressure around the outer wall oi the inner casing with respect to the fluid pressure within said casing b providing a plurality of flanges around t e inner wall of the outer casing, and a, plurality of flanges around the outer wall of the inner casing that are constructed to seat against the said flanges in the outer casing and form a plurality of separate chambers around the outer wall of the inner casing, means being provided to separately connect each of the said chambers to the fluid pressure inside of the inner casing in such a manner that will cause the respective fluid pressures on the inside and around the outside of the inner casing to most nearly balance to reduce the internal pressure strain on the inner casing.

It is another object of the invention to provide resilient packing between the said flanges to properly seal the diflerent chambers between thesuction and the discharge and to also permit the casings to expand when the pump is used for pumping hot fluids.

It is another object of the invention to provide means to prevent all. possibility of the pump getting out of alignment, when the pump is used for pumping hot fluids, as the result of the metal expanding, which often causes the outer casin to move unevenly on each side of the vertical center line of the pump.

The invention further consists in the particular combination, construction and association of the different parts such as described in the following specification and possesses other objects and features of advantage, some of which, 'wlth the foregoing will be made manifest in the following description of the preferred form of the invention that is illustrated in the drawings accompanying and forming part of the specification.

It is to be understood that it is not intended to limit the invention to the embodiment shown by said drawings and description, as variations may be ada ted within the scope of the invention as set orth in the Claims.

In the accompanying drawings:

Figure 1 is a central longitudinal sectional view of a preferred type of pump involving the invention.

Figure 2 is an outer end view of the pump, looking toward the driven end, showing one method of keying the outer casing to the base to keep the pump drive shaft in positive true ali ment.

igure 3 is an outer end view of the inner casing, looking toward the suction end, and illustrates one method in which the said inner casing may be constructed.

Figure 4 is a side elevational view of the inner casing, showing a plurality of flanges provided thereon.

Referrin in detail to the different parts wherein li e reference numerals designate corresponding partsthroughout the several views, the numeral 6 designates an outer casing that may be made in any suitable form and of any suitable metal, and the numeral 7 designates an end'cover that is mounted thereon and fastened thereto by bolts or studs 8 as shown in Figure '1. Numerals 9 and 10 designate the suction inlet and discharge outlet respectively' The numeral 12 designates the inner casing which is preferably of the standard horizontal split type but may be any standard type that will serve the purpose of the invention. The upper half and lower half of the inner easing are, desi ated by letters a and b res ctively in igures 3 and 4, and the said ha ves are substantially fastened together by means of bolts 14 as illustrated.

In Figure 1 there is illustrated a multistage centrifugal pump showing a main drive shaft 15 and four impellers 16, 17, 18 and 19 that are substantially fixed thereon. It is to be understood that any suitable number of impellers may be used and arranged on the shaft in any suitable manner to serve the particular class of work that the pump is to perform, and that the said inner and and outer casings may be made in proportion to serve any suitable number of impellers. The shaft 15 is provided with replaceable steel sleeves 20 and 21 and is supported in bearings 22 and 23. The bearing 22 is bolted to the inner casing 12 and is centered and supported in the end cover 7 that is bolted to the be outer casing. Likewise the bearing 23 is bolted to the inner casing 12 and is centered and supported in the outer casing 6. -Replaceable bearing liners 24 and 25, respectiveare mounted in the said bearings 22 and 23. Numerals 26, 27 and 28 designate replaceable rin s that are tightly mounted on the hubs of t e impellers 17, 18 and 19, and numerals 30, 31, 32 and 33 designate replaceable rings mounted in the inner casingl for revolubly supporting the impeller ubs. Numerals 29, 34 and 35 designate dividing rings and numeral 36 designates a bushing mounted on the shaft between the impellers 17 and 19.

As hereinbefore stated, one of the objects of the present invention is to reduce the internal pressure against the outer casing end cover, or in other words, to prevent the full discharge pressure from being applied against the said end cover. A preferred method used to prevent the full discharge pressure being applied against the said end cover is shown in Figure 1, andcconsists in providing a separate chamber 37 between the inner casing and the end cover and providing a passage 38 that leads from the said chamber to the inside of the inner casing at a point where the fluid pressure is considerably low er than the full discharge pressure of the pump and thus convey the said lower pressure in the chamber 37. This chamber is preferably formed as illustrated, by formmg a chamber portion in the cover 7 and by providing a flange 39 around the discharge pressure end of the inner casing and mountmg said flange against the outer flange 40 of the outer casing and thus com letely separate the said end cover 7 from t e inside of both the inner and outer casing. The assage 38 may lead to any of the different uid passa' e ways in the inner casing that will give 518 desired pressure in the chamber 37. The present construction shows the impeller 16 located at the fluid inlet 9 and the fluid will enter the said impeller 16 and then be delivered to impeller 17 then to impeller 18, then to impeller 19 whence it is forced out of the discharge outlet 10. Assuming that each impeller increases the fluid pressure pounds per square inch it will be seen that the fluid will be delivered from the impeller 16 at ressure of 100 pounds per square inch, and om impellers 17, 18 and 19, at'200, 300 and 400 pounds respectively. The passage 38 in the present illustration is shown leading into the discharge passa e way of the impeller 18 where the flui pressure would be 300 pounds pressure per square inch, or three-fourths of the full discharge pressure at the outlet, and it will thus be seen that only three-fourths of the full discharge pressure will be applied against the end cover. It will also be seen that there will no strain on the bolts 65 that hold the inner casing to the outer casing, the said bolts bemg used for safety and to alwa s hold the said flange tight against its seat in the outer casing. An opening 41, having a pipe plu 42 threaded therein, is shown in the en cover 7 so that the gases that form when pumping hot oils may be vented from the chamber 37.

Another object of the present invention is to provide a pluralit of other chambers around the inner casing so that different pressures may be separated and to form these chambers in such a manner that very little additional cost will be added to the construction. In Figures 1 and 4 there is shown a plurality of flanges 43 and 44 provided around the inner casing. The outer casing is also provided with flanges 46 and 47 that extend around the inner Wall of the said outer casing, and are spaced at such distances apart relative to the flanges on the inner casing that when the said inner casing is mounted in posltion the respective flanges on both the inner and outer casings will fit against each other as shown in Figure 1. suitable'gaskets, or

resilient packing rings 48, 49, 50, 51, 52 and- 53 are provided and located in their respective positions between the different flanges so that a tight seal will be assured and also to permit expansion and contraction of the metals when pumping fluids of various excessive high temperatures. Annular grooved olnts are preferably provided to seal the end cover to the outer casing and also to seal the inner casing end flange 44 against the outer casing flange 47 to tightly seal the space around the inner casing from the suction lnlet.

From theforegoing it will be observed that a plurality of separate chambers 54 and '55 are provided between the innerand outer casing and that each chamber is tightly sealed from each other. A threaded hole 56 is rovided in the inner casing to connect the uid I passage way of the impeller 17 to the chamber 55. A pipe plug may be threaded in the hole 56 should it ever be desirable to close the sa d passage way from the chamber 55. It Wlll be seen that the fluid under pressure from the low pressure impellers is admitted in the chamber 55 through the hole 56 and will exert a pressure-around the inner casing'that Wlll partially balance the fluid pressures exerted within the low pressure end of inner casing. Likewise the chamber 54 is open to d1scharge pressure through the inner casing discharge outlet 57 (see Figure 4) and the full discharge pressure is admitted in the said chamber 54 and, applied against the inner casing, and will partially balance the fluid pressures exerted within the discharge pressure end of the inner casing.

As the present type of pumpis generally used for pumping hot oils that often have various excessive high temperatures, that cause the metals to expand in varied amounts, it is very important that provision be made that will prevent any and all possibility of the expansion of the metals from forcing the drive shaft out of alignment or from interfering with the proper operation of the Workthe result of the different temperatures.

ing parts in any manner. Explanation has 7 already been made of a preferred means and tract longitudinally without danger to breakage of the casings when the parts expand or danger of leakage when the parts contract it has been found in actual practice that when the casings expand transversely the outer cas ing, in which the bearings are centered, often moves unevenly on one side of the vertical center of the pump instead of moving evenly on both sides thereof. This uneven move ment of the casing on one side of the vertical center of the pump causes the drive shaft to get out of alignment and to bind in its bearings, resulting in much friction and wear, and requires extra power to operate the respective parts and thus reduces the mechanical efficiency of the pump. Means is therefore provided that will positively prevent the said casing from expanding unevenly on p either side of the vertical center line of the pump. A preferred form of such meansnis illustrated in Figure 2 and consists in providing a key, or a plurality of keys 58 on the outer casing and providing a keyway 59 in the base 66 and key the said outer casing to the base. It is very important to key the said casing to the base directly on the vertical center line of the pumpand thus absolutely prevent the casing from moving more on one side of the vertical center of the pump than the other. However, it is to be understood that anysuitable method for keying the cas: ing to the base that will serve the purpose of the invention may be used. In other words, any suitable number of keys may be used and formed directly on the casing, or

' formed separately, and fastened on the easing in any suitable manner. Likewise, the keyways may be formed directly in the base or may be formed in a separate piece and fastened to the base; While it is preferab e to key the casing on the base directlyon the vertical center line of the pump, it is to be understood that a plurality of keys may be provided and, arranged on each side of the said vertical center of the pump and serve practically the same purpose.

Any suitable method may be used for packing the drive shaft, the present construction showingstandard packing 59 preferably enclosed by a hous ng 60 and adapted to be ad- 'justed by a suitable means operative outside of said housing.

volved in the general assembly, but it is not considered necessary to descrlbe the various details as they comprise regular standard construction that arenot deemed a part of the invention.

From the foregoing it will be seen that the invention involves special construction and possesses many advantages. The various chambers are formed around the inner caslng without the addition of any complicated parts, adds practically no extra cost to the construction, and the admission of fluid pressure into thesaid chambers around the inner casing relieves much strain on the metal caused by the fluid pressures within the inner casing. It will be noted that the various flanges on the inner casing are all of a different diameter, that is, the inlet end flange 44 has a less diameter than the flange 43 and the flange 43 has a less diameter than the discharge end flange 39. This is necessary so that the pump can be assembled. It will be noted also, that the pump is very simple to dismantle. Fastening the inner casing end flange 39 to the outer casing positively holds the inner casing in position, prevents any movement of one casing within the other, relieves strain on the drive shaft, and positively holds the inlet end of the inner casing against the inlet end of the outer casing. The providing of the different resilient gaskets between all of the diflerent flanges allows for metal expansion and yet always keeps the different compartments positively sealed. Keying the outer casing to the base positively prevents the drive shaft from getting out of alignment as the result of metal expansion. The provision of a separate chamber between the end cover and the inner casing and reducing the fluid pressure in said chamber as described prevents many thousands of pounds of fluid pressure from being exerted against the end cover and thus removes much excessive strain against the end cover and the bolts that hold the cover to the outer casing.

Having thus v illustrated and described a certain form of construction and arrangement of parts pertaining to the invention, it is to be understood that any standard type of inner and outer casing may be used, which, obviouslyffnay be built up in any suitable manner, the present illustration not being utilized as indicating the only arrangement and form of construction in which the parts may be made; and it is desired to include in this application for Letters Patent of the United States of America, any andall patentable novelty that exists in the invention disclosed and all that comes within the fundamental principle of the invention as set forth in the claims hereinafter mentioned.

What is claimed:

1. A fluid pressure pump comprising an outer casing with an open end; a horizontally split casing mounted therein; a removable end cover on said open end of the outer casing; a fluid inlet and a'discharge outlet in each of said casings; the space between said casings being in communication with the dis charge outlet; means for sealing said space with respect to the fluid inlet; impeller means adapted to pump fluid revolubly mounted in the inner casing; an annular seat in the discharge end portion of the outer casing; a flange on the discharge end portion of the inner casing and arranged adjacent the end cover of the outer casing; space between said flange and the end cover; packing means between said seat and flange; means for fastening said flange and packing against said seat in the outer casing and fluid conveying means leading from the inside of the inner casing at a location where the fluid pressure is below the maximum discharge pressure to the space between the flange on the inner casing and the end cover on the outer casing.

2. A fluid pressure pump comprising an outer casing with an open end; a horizontally split casing mounted therein; a removable end cover-on said open end of the outer casing; a fluid inlet and a discharge outlet in each of said casings; space provided between the outer Wall of the inner casing and the inner wall of the outer casing; means for sealing said space with respect to the fluid inlet; a plurality of impellers, adapted to pump fluid, revolubly mounted in said inner casing; a flange on the discharge end portion of the inner casing and arranged adjacentthe end cover of the outer casing; space forming a chamber between said flange and end cover; means for dividing the space between the inner casing and outer casing to form a plurality of chambers around the inner casing; compressible means for sealing said chambers with respect to each other; means for sealing the space formed between the casings from the space formed between the end cover and the inner casing; means for separately connecting each of the chambers around the inner casing to the .inside of the inner casing to convey difl'erent fluid pressures in each of said chambers; and a port leading from the inside of the inner casing at a location Where the fluid pressure is below the maximum discharge pressure to the chamber between the inner casing and the end cover on the outer casing.

In testimony whereof, I hereunto aflix my signature.

MICHAEL D. AISENSTEIN.

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