US2635552A - Sanitary pump assemblage - Google Patents

Description

April 21, 1953 v. F. DALE ETAL I 2,635,552

' SANITARY PUMP ASSEMBLAGE Filed Jan. 31, 1949 26 23 38 4o 4/ W4 i97 i il 39 ATTOF/YEYS',

Patented Apr. 21, 1953 2,635,552 SANITARY PUMP ASSEMBLAGE Vernon F. Dale and George Reed, Onalaska, Wis., assignors to The Bump Pump 00., La. Crosse, Wis., a corporation of Wisconsin Application J anuary 31, 1949, Serial No. 73,738

6 Claims.

Our invention relates in general to improvements in the art of transporting liquids through conduits or the like, and relates more specifically to various improvements in the construction .and operation of liquid transfer pumps especially adapted to handle diverse commodities such as milk, syrups, and other beverages. -The primary object of the present invention is-to provide an improved pump assemblage which is simple in construction, eflicient in operation, and all parts of which are readily accessible for inspection.

Rotary pumps driven by electric or other kinds of motors through speed reducing gearing, have heretofore been used in many industries for the purpose of transporting various beverages such as milk, syrups, and the like. When handling commodities of this kind, it is essential that the pump assemblages be constructed so as to'permit convenient internal and external cleaning in order to maintain the structures in highly sanitary condition. It is also desirable when utilizing positive displacement pumps'for liquid, to make provision for preventing overloading of the units and excessive pressures in the liquid conducting conduits. Then too, when propelling certain types of commodity, it is desirable to transfer the liquid with positive action, at slow speed, and without excessive agitatiomwhile also insuring self priming of the pumps. Whenthe pump is located in close proximity to the-speed reduction gearing, it is furthermorenecessary to prevent lubricant escaping from the gear chamber, from entering the pump displacement chambers; and none of the prior motor driven rotary pump assemblages have effectively met all of these requirements.

'It is therefore an object of our present invention to provide a simple, compact and durable positive displacement rotary pump unit, which embodies all of the above mentioned necessary and desirable features, and which is well protected against excessive pressure while also being readily cleanable.

Another important object of this invention is to provide various improvements in the details of construction of rotary double impeller liquid pumps, whereby such mechanisms may be quickly and conveniently assembled or dismantled, without disturbing the gearing which normally drives the impellers.

A further important object of the invention is to provide an improved rotary pump and gear housing assemblage wherein the pump is dis--v posed closely adjacent to the gearcasing, and

the latter may be provided with abundant lubrication without permitting escaping lubricant to enter the pump displacement chamber.

Still another object of our, invention is to provide an improved seal for the shafts of rotary gear driven pumps or the like, which will effectively seal the pump displacement chamber while still permitting rapid dismantling and reassembly ofthe pump structure.

. An additional object of the present invention is. to provide improved mechanism for preventing attainment of dangerously high pressures in positive displacement rotary liquid pumps, which may be readily applied to new or old pump units, and which functions automatically to relieve abnormally high discharge pressures.

Another object of our present invention is to provide an improved sanitary liquid pump composed of relatively few simple parts, and which may be manufactured in various sizes and for diverse uses at moderate cost, while requiring minimum attention during normal operation and in order to maintain the structure in highly sanitary condition.

These and other. objects and advantages of the invention will be apparent from the following detailed description.

A clear conception of the several features constituting our present improvement, and of the construction and operation of a typical pump unit embodying the same, may be had by referring to the drawing accompanying and forming a part of this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. l is an explodedperspective view showing one of our improved gear driven sanitary pump units partially dismantled for cleaning purposes, and with the pump casing inverted;

Fig. 2 is an enlarged central longitudinally vertical section through the unit of Fig. l, but showing the same fully assembled;

Fig. 3 is a section through the automatic flow control or pressure relief valve mechanism of thepump unit, the section having been taken along the line 33 of Fig. 2; and

Fig. 4 is'a further enlarged central longitudinal section through one of our improved rotary shaft seals and through adjacent pump structure.

While the invention has been shown and described herein as being advantageously applicable to rotary gear driven liquid pumps having two cooperating double-lobe impellers, it is not our desire or intention to unnecessarily limit the utility of theimproved features by virtue of 3 this restricted embodiment; and it is also contemplated that specific descriptive terms used herein be given the broadest possible interpretation consistent with the disclosure.

Referring to the drawing, the sanitary positive displacement liquid pump unit shown therein, comprises in general, a one-piece pump casing 6 having upper'and lower bores l, 8 respectively in open communication with each other, and also having intake and discharge conduits 9, l respectively communicating with the space between the bores l, 8 on opposite sides of the casing: 6; a pair of upper and lower double-lobe rotors or impellers I I, l2 rotatable within the casing bores i, 8 respectively and normallyi'ntermeshing; with each other between the conduits 9, ID, the impellers being rigidly secured to parallel drivingshaftsi l4, [5 respectively projecting from corresponding sides thereof and each being provided with an enlargement l6 adjoining its rotor; a one piece gear housing I! located at one side of the pump casing 6 and providing a gear chamber H3 which is accessible upon removal of a detachable closure plate 19 and which is also-pierced by the parallel horizontal impeller shafts l4, l5; outerand inner pump closure heads 28-, 2| coacting respectively with the outer flat surface of the casing 6 and with the adjacent inner'flat-surfaces of the casin 6 and housing ll; driving sleeves 23,. 24 embrace ing the upper and lower shafts l4, l5 and being detachably secured thereto; inter-meshing similar motion transmitting-gears 25 secured to-the adjacent sleeves 23, 24 within the chamber l8 by means of keys 26; and a power shaft 2'! journalled in the housing I! and having a. pinion 28 secured to its inner end within the chamber l8 and drivingly coacting with a gear 23 keyed to the lower sleeve. 24, while the outer end 30 of the shaft is flattened for connection to a driving motor by means of a coupling 3 l The twoimpellers Il 12: of the pump may be formed integral with or firmly permanently secured to their respective driving shafts l4, H5 in any suitable manner, and when assembled for operation these impellers snugly coact with the casing bores l, 8 and constantly contact each other during rotation thereof, so as to continuously withdraw liquid from a source of supply through the intake conduit. 9 andv to deliver the liquid under pressure through the discharge conduit Ifl. Thecasing end heads 20,2! of the pump are also adaptedto coact snugly with the opposite ends of the rotors or impellers Hi, 52, and are capable of being clamped to the pump casing 6 and to the gear housing L'l' through intervening gaskets, by means of studs33 secured to. the housing I? and wing nuts 34 coacting with the outer threaded. ends of the studs 33, as illustrated in Fig. 2. The pump may therefore bequickly dismantled without the aid of. special tools by merely releasing the wing nuts 34 and by thereafter sliding the outer head 28,. casing 6, and inner head 2| off of the-studs 33' in succession, as exemplified in Fig. 1; and the rotor enclosure. may be just as rapidly reassembled: by reversing these. operations, while two dowel. pins 35 secured to the housing l'l' and coacting with holes 36 insure proper assembly of these parts; It is to be noted that the removed pump casing 6 of Fig. 1 has been inverted in order to clearly illustrate the manner in which the impellers coact with the bores thereof, and the sealing gaskets have also been omitted for the sake of clearness.

The rotors or impellers H, l2 of the pump together with their supporting and driving shafts l4, l5 may also be freely removed from the casing 6 when the outer end head 2!! has been removed and the shafts are released by sliding these shafts l4, l5 longitudinally from within their respective driving sleeves 23, 24, and without disturbing these sleeves or the gears 26, 29- carried thereby. The shafts i4, it are each provided with a tapered section 31 adjoining the enlargement It thereon, and adapted to wedgingly engage similar tapers formed in the adjacent ends of the sleeves 23, 24, and the opposite outer end of each of these sleeves beyond the confines of the housing 11, is normally drivingly attached to the corresponding shaft l4, [5 by a' key 38 formed integral with a collar 39 which embraces the reduced threaded end 40 of its shaft and coacts with the sleeve end, see Fig. 2. Amanually operable clamping nut 4i coacts with each of the threaded outer shaft ends 49 and with the adjacent collar 39 to simultaneously hold the adjoining key 38 in place and to force the corresponding sleeve taper into snug frictional driving engagement with the adjacent shaft. tapered. section 31, thereby providing a positive but readily releasable driving connection between each rotor shaft l4, l5 and its embracing sleeve. '23, 24.

Each of the sleeves 23, 2.4 is journalled for free rotation within the housing I! by means of two anti-friction bearings 43, 44 which coact with shoulders. on these sleeves. so as to prevent longitudinal displacement or shifting thereof, see Fig. 2. While these bearings 43; 44 are shown as ball bearings, they may be of any other anti-friction type,- and the bearing 43 nearest the pump ispreferably of the double-ball or roller type due to the greater load to which it is normally subjected. The anti-friction bearings 43', 44 are exposed to the gear chamber I3 but are sealed from the ambient atmosphere by sealing rings 45; and the gear housing H is provided with an external drain passage 46 at its end nearest to-the pump closure plate of head 21,. in order to prevent lubricant which may escape past the adjacent sealing rings 45 from reaching the pump assemblage. The gear chamber i8 is. also preferably provided at its lower portion with a lubricant supply and drain fitting 47, and with a vent plug 48 at its upper portion, the: latter serving to relieve undesirable pressure which may result from overheating.

As previously indicated, the flattened outer end 30' of the power shaft: 21 may be connected to an electric motor or othersource of power: by a coupling 3|, and the medial portion. of this shaft journalled; for. free rotation in the gear housing [1%, while its. inner end carries the driving pinion 28 which meshes with the larger gear 29 within. the chamber l8, thus providing speed reduction. The gear 29 may be drivingly attached to the lower sleeve 24 by means of the same key 26'which attaches the lower gear 25 thereto, and the upper gear 25 is likewise drivingly attached to the upper sleeve 23' by means of a shorter key 26. In order to prevent the gears 28, 29 from shifting along their respective supporting sleeves 23, 24 set screws 49 may be provided as depicted in Fig. '2; and the gears and pinions maybe inserted and assembled within, or removed from the chamber I8 upon removal of the closure plate l9- after withdrawal of the lubricant with which this gear chamber should be abundantly supplied during: normal operationv of the unit. It is to be noted that all transmission gears are normally supported only by the sleeves 23,. 24 so that the: shafts l4, l5 may be withdrawn from within these sleeves without disturbing the gearthe seal rings 45..

. In order to make doubly sure that no escaping lubricant will reach the pump displacement chambers, while still permitting quick assembly or dismantling of the pump, we also provide improved packing or sealing assemblages 50 surrounding each shaft enlargement I6, and the detailed construction of one of which are illustrated in Fig. 4; These packing assemblages are of like formation, eachcomprising a metal ring 52 having a wedgeshaped tranverse cross-section and coacting with a metal ring 53 having an L-shaped transverse cross-section along a plane surface 54 disposed perpendicular to the shaft axes; and apairof resilient or rubber sealing rings 55, 55 each having circular transverse cross-section and coacting with the metal rings 52, 53 respectively and with adjacent pump structure. Thering 52 has a wedge surface 51 coacting with the rubber ring 55 to press the latter against the shaft I4,

I5 and against the adjacent impeller or rotor I I, I2, thus causing these rings 52, 55 to normally revolve with the rotor and shaft assembly. The L s-shaped ring 53 likewise coacts with the rubber ring 56 to press it against an annular lip 58 formed on the pump closure head 2 I, thus fixing these rings 53, 56 against rotation, so that the rings 52, 53 normally have snug sliding contact at .the flat surface 54, and an efiective seal is produced by the pliable or resilient rubber rings 55,

56 when the seal is assembled by merely inserting the adjacent shaft-I4, [5 within its supporting . sleeve 23, 24 and by causing the corresponding impeller I I, I2 to contact the end head 2 I. These sealing assemblages 50 may, however, be just as conveniently dismantled by withdrawing the impellers and shafts, as indicated in Fig. 1.

When the improved positive displacement pumps are operable under relatively high pressures, it is prefereable to provide an automatic flow control or pressure regulating device, an

improved version of which is shown in Fig. 3. This device consists primarilyof an auxiliary hollow casing 60 secured to the outer pump head .20 by any suitable means such as cap screws 5|, and adapted to connect the pump discharge conduit I0 with the pump intake conduit 9 through openings 62, 63 respectively formed in the head 20; a plunger 64 slidable within a bore in the casing and being snugly cooperable with the opening 62 to throttle the flow of by-passed liquid from the pump discharge to the intake; a pressure regulating cap 66 adjustable with the aid of screw threads 61 longitudinally of the casing bore and a helical compression spring 58 surrounding a stem 69 formed on the plunger 64 and having its opposite ends secured to and coacting with the cap 66 and plunger 64. The cap 65 may be manipulated to cause the plunger 64 to'enter the opening 62 more or less so as to cause excessivedischarge pressure to be-automatically released to the pump suction while the pump is operating,-and the position of the cap 66 determines 'the magnitude of the discharge pressure at which the relief device will act.

nected-respectively to sources of liquid supply and demand when rotative power is applied to site rotary motion to the shafts I4, I5 and impellers I I, I2 thereby causing liquid to be constantly withdrawn by the revolving and coacting impellers from the intake conduit 9 and to be delivered under pressure into the discharge conduit II). The pressure at which this delivery takes place, may be accurately controlled byadjusting the cap 66, and any abnormal pressure rise occurring in the discharge line will be automatically relieved by the plunger which will then be forced entirely out of the opening 62 and will permit liquid to by-pass from the pump discharge to the intake.

When it becomes desirable to clean the pump, it is only necessary to remove the thumb nuts 34 from the studs 33, and to thereafter successively remove the outer end head 20 and the rotor casing 6 of the pump assemblage, whereupon the impellers II, I2 and their driving shafts I4, I5 may be quickly withdrawn upon release of the assembly nuts 4I from the threaded shaft ends 40. This withdrawal of the shafts I4, I5 will also partially or completely remove the sealing assemblages 5B, and the inner end head 2| may then be finally removed to completely dismantle the pump. After the various parts of the pump have been inspected and thoroughly cleansed, they may be just as quickly and conveniently reassembled to restore the pump to operating condition, and in order to facilitate rapid cleaning, the intake and discharge conduits 9, I0 should preferably be provided with quick detachable couplings of wellknown structure. The sleeves 23, 24 and the gears 25, 28, 29 associated with the housing I1 will not be disturbed during ordinary dismantling and reassembly of the pump; but if it becomes desirable to also dismantle these sleeves and gears, this may be readily accomplished by removing the lubricant and the closure plate I9, and by releasing the bearing confining rings 45 from the housing 1.

From the foregoing detailed description of the construction and functioning of our improved pump assemblage, it should be apparent that we have in fact provided a positive displacement rotary liquid pumping unit which is simple and exceedingly compact in structure and efficient in operation, and which may also be readily maintained in sanitary operating condition with minimum effort and loss of time. The sealing rings 45, drain passage 46 and the packing assemblages 50 cooperate to effectively prevent escaping lubricant from entering the pump casing; and the improved mounting of the impeller shafts vastly facilitates dismantling and reassembly of the pump without disturbing the gearing or the driving mechanism. However, when the keys 38, rings 39 and nuts M are applied to the sleeves 23, 24 and shaft ends 40, the sleeves 23, 24 are positively secured to their respective shafts I4, I5 both at the tapered portions I6 and at the outer shaft ends 40, and the dismantling and reassembly operations can be carried on without the aid of special tools and are greatly facilitated by the use of our improved packing assemblies 50. The improved pressure regulating and relief device when used, effectively and safely controls the maximum pressures attainable in the discharge conduit I0; and when thisdevice is not required the openingstzg fis-in 'theheam20:maybe:plugged "and the casing 60 and associated :parts" maybe omitted. The -improved pump-assemblages. may be -manufactured atrmoderate cost. in various sizes and-for diverse uses, and have :proven :highly satisfactory and'reliable. in actualoperation with 'very little attention required. Whentused with "certain commodities "the parts exposed :to Ifth'e li-quid are 1 preferably formed of rust :resistant #material, and whenoperating at relativelysslow "speedithe impellersi l 'l 2 -will pro'duce minimum .agitation, "but: the pump is self priming at 2.11 times regardles ofthef speed of. operation.

It should be understood that it:..is-: not desired tol lirnit this invention to the exact tdetailssof construction 01913017118 lprecisemoderof operation of the typical pump herein. shown and. described, ior''various modifications within ithe;scopei'of.,the

appended claims may occurtto personsrskilledin We 'claim:

i l JIn Ka -pump .assemblage, ran impeller: casing;.a unitar.y. geariheusing. having-.integraleerid; closure -walls -one of whichuis :secured cdirectlyitousaid teasing,v a pair of 5. parallel :sleeves journalledI-for :rotation in: said. .housing 'wallsa and spannin the 5 interior of l the housing abutv being rheld against --longitudinala=displacement, :each .of said :sleeves having :r aiteentrallfbore and an internal ;frustrovconicaksurfaceat theendzof saidiborenearestto =..=.externally .of saidhousing, each of said shafts asnugly :fitting ;.the..adjaeent1s1eeve :bore and :havaingaa :mediaLirustro-co'nical outer surface like- Wise fitting .the adj acentfrustrmconical sleeve esurface, vcoacting pump impellers permanently secured: to theashaft ends disposed within said -casing;a1id:.-means manipulable from the exterior .Z-OfiESid :casing and housing. for detachably drivzzinglyc.connectingtheexternal shaft-ends with the ealdj acent-ends .of said sleeves-and for forcing: the complementary l inner and outer? frustro-conical -surfacesk together.

2. In a pump assemblage, an impeller.casing, 5:asunitary geanhousinghavingintegralendxzlosure twa'l-lsione 'of-fwhich. is-tsecured: directly to; saidcassiinggaspair :of. parallel isleeves': journalled; forrrota- 'cttonlinsaidt housing wall and spanning .rthefinterior of the housing butzbeingheld against-longi- :tudinal idisp1acement,-each of said: sleevestihaving -a::centr'a1 :bore and an internal frustro co'nical -sur face at' the end ofsaid borelnearest to -said iicasing, lintermeshing gears i. for rotating :said 'sleeves a shaft'extending: longitudinally through "'each of said sleeves and having opposite ends proj ectingxbeyondliits (sleeve into said easing: and i externally nofisaid housing, :each :of ":said ashafts snugly fitting-the adjacent" sleeve bore aridhaving a medial frustro-conical outer surface likewise fitti ng theadjacentfrustro-conical-sleevesurface, coacting'pump impellers-permanently secured to iithe shafte ends disposed -within' said casinggand wmeans manipulable from the' exterior of said 'casling "and housing for detachably "drivingly conanecti-ng the external shaft-ends with the adjacent tends; of said-sleeves andfor 'forcing thecomplementary' inner and outer fru'stro-conical' surfaces together, said shafts being longitudinally removable from *within said sleeves only-upon release not said connectin meansand \vithout disturbin 38 --unitaryz gear :hoxi'singhavingeintegral fopposite 'T'ClOSIlI'B xwallsiito :one ,of-"Whicht said ca'singisisecured, '::a :pair 10f ;parallel:1sleeves journalled for rotation in said housing wallsuand'fspanningithe interior .i of :said .;housing, each .I of saidisleeves :having :.a central bore and Ian: :internalrzfrustro- ;conical:surface .at;the :end of :saidfboretnearest'zto said'rasing, i antiefrictionbearings-for. said; sleeves mountedzinisaidwallsaandrbeing formedto permit free-.rotationroffthe;sleeves. butpositivelyipreventping-longitudinal displacementthereof, :intermeshi'ing'gears: carriedi'bysaicl sleeves iwithin saidhousing for transmitting ":rotary :motion Z -TIOm tone sleeve ito fbhe .:other, :aiishaft :extendin'g longitu- .dinally. through'- each ofisaidisleeves and having 1 opposite :ends proj ectingbeyond its sleeve into said xoasing-riand externally .of said housinggeach of said" shafts snugly Lfittingr the:zacljacent; sleeve .boreand.having -a; medial frustroeconical outer surface likewise fitting '1 the adjacent frustroconical :s'leevefsuriace, rcoacting pump impellers permanently secured-"to the: shaft ends disposed witliinisaid :casing,:and .means coaoting' wi'th; said shafts and the-adjacent sleeves externa'lly-of said casing? and saidshousing fordetachably driving'ly :.-c0nnectingl the external shaft ends-with theadiacent 1 sleeve ends and for f forcing "the complementary inner and outerzfrustrmconical surfaces together.

4. In a pump assemblage, an impeller casing, -a unitary l'gear housing having 'integral opposite "closure walls to cheer "which said casing is secured, a pair' of parallel sleeves. journalle'd for rotation insaid housing-walls andspanning the interior of-said housing, each 'of -saidsleeves having :a central bore and-" an internal frustroaconical surfaceatthe endof said here nearest to said 'casing, anti friction bear-ings -for said sleeves mounted-in said walls-and being -for-med to permit 1 free rotation -of the sleeves but positively preventing longitudinal "displacement thereof; intermeshing gears carrie'dby-sa'id'sleeves within said housing for transmitting rotary 'mo- 'tion from one-sleeve to-theotherya shaftext'en'ding l-ongitudinally through each or sai'd sleeves 'and having opposite ends projecting beyond its sleeve into saidmasing and'externeilly of -'said housing, *each' of said *shafts "snugly fitting the adjacent 'sleeve bore and havingamedial frustroconical outer surface likewisefitting-the adjacent 'frust1'e=conica1 sleeve surface, "coac'ting pump -impellerspermanently secured'to the-shaft ends disposed within'said casing," and means oacting with said shafts and the "adjacent 'sleeves 'ex-ter- 5 'nally 0f said casing -an'd said-housing for detach- :3.7TIn1aipump assemblage-ran"impeller casingpa 7 5 ablydrivingly connecting the externalsha'ft-"ends *with-the adj acent-sleeve ends-and f or forcing the complementary inner and outerirustro-conical surfaces together;said shafts'with their'impellers being axiallyremovable from said sleeves only upon'release of said connecting mea'nsand without disturbing saidgears.

" 5. "In a purnpassembIage, -an impeller casing, a gear' housinghaving 'oppesite end closure walls one of which is secured to said casing, parallel 'sleevesjournalledin said-housing walls and span- -ning the interior of the' housing "but "being held against longitudinal displacement, =each of said "sleeves having a a central "bore "and an Y internal frustro-conical suifaceat the end of'said" bore nearest to sa'id'casing, interme'sh'ing gears for'imparting rotation from one of *sai'd sleevesto the "other, a shaft extending l longitudinally "through :eachofsaid'sleevesand"having opposite'ends'pro- "jetting ibeyond its 'sleeve "into *"said casing and externally of said housing, each of said shafts snugly fitting the adjacent sleeve bore and having a medial frustro-conical outer surface likewise fitting the adjacent frustro-conical sleeve surface, coacting pump impellers secured to the shaft ends within said casing, and means manipulable from the exterior of said casing and housing for detachably drivingly connecting the external shaft ends with the adjacent ends of said sleeves and for forcing the complementary inner and outer frustro-conical surfaces together.

6. In a pump assemblage, an impeller casing, a gear housing having opposite end closure walls one of which is secured to said casing, parallel sleeves journalled in said housing walls and spanning the interior of the housing but being held against longitudinal displacement, each of said sleeves having a central bore and an internal frustro-conical surface at an end of its bore, intermeshing gears for imparting rotation from one of said sleeves to the other, a shaft extending longitudinally through each of said sleeves and having opposite ends projecting beyond its sleeve into said casing and externally of said housing, each of said shafts coacting with the adjacent sleeve bore and having a medial frustroconical outer surface snugly fitting the adjacent frustro-conical sleeve surface, coacting pump im- References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Grindrod July 11, 1899 Tucker Apr. 28, 1903 Kiefer July 14, 1914 Smith Nov. 26, 1918 Needham Aug. 9, 1921 Wardwell June 10, 1924 Troendly July 19, 1927 Wiltse Jan. 14, 1930 Vogt et a1 Mar. 21, 1933 Peter June 6, 1933 Schneider Mar. 24, 1936 Hansen Oct. 19, 1937 Thomson June 6, 1939 Dietzel Mar. 12, 1940 Thomson Jan. 14-, 1941 Thomson July 1, 1941 Spengler Dec. 16, 1941 Funk Apr. 7, 1942 Marco June 15, 1943 Burrus Dec. 12, 1944 Heimbach Jan. 16, 1945 Wallgren Sept. 17, 1946 Schmitter May 11, 1948 Namur Feb. 22, 1949 FOREIGN PATENTS Country Date Germany Nov. 7, 1935

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