US2247454A - Pump seal - Google Patents

Description

July 1, 1941. A TH'QMSON 2,247,454

PUMP SEAL Filed Sept. 26, 1959 I N VEN TOR.

M T I I 477% A TTORNEYS.

ldtentedluly l, 1941 f age prevention roivmsa'aa' Leroy Albert Thomson, La Crosse, Wis, assignor to Bump Pump Company, Ilia. Crosse, Wis, a corporationof Wisconsin Application September as, 1938, Serial No. 231,669

2 Claims. 7 (Cl. 286-7) The present. invention. relates generally to improvements in the art of propelling fluids, and

relates more specifically to improvements in the' con-struc'tion'and operation of pumps for im- P lling liquids.

Generally defined, an object of my invention is to provide an improved pump assemblage which is simple and compact in construction and which is moreover highly eflicient in use.

Some of the more specificobjects of the inven-tion are as follows:

To provide an improved pump wherein undesirable churning of liquid such as oil or milk is eliminated in all portions of the. assemblage.

To provide a dairy pumpwhich fully meets the statutory and other requirements as to sanitation and health.

' times will be apparent from To provide a. pump-especially adapted for use in industries such as the dairy industry, which is sanitary in use and which may be readily maintained in sanitary condition. 1

To provide an improved pump assemblage which are rather diflicult to confine.

readily assembled anddismantled, and all inspectionncleanlng and replacement.

To-provide a durable high pressure pump which is efi'ectlvely sealed against possible escape of the fluid being pumped, and which requires minimum. attention when in normal use.

To provide an improved self-sealing rotary shaft packing for pumps or the like, which may be quickly and conveniently applied or removed and all par-ts of which are. readily accessible for cleaning.

To provide a new and useful pumping unit for liquid such as milk or cream, which is devoid of pockets, crevices or corners wherein solid substances are apt to accumulate and wlii'ch are not readily accessible for cleaning.

To provide a positive displacement pump as semblage wherein the fluid impelling members or rotors, as well as their supports and driving-members are readily accessible and removable.

To provide an improved pump drivingassemblage in which 'theelements are firmly held in operating condition and cannot become dislodged.

during normal operation of the assemblage.

To provide an improved pump drive and leak- "Io provide a be readily manufactured. and which is operable with minimum power consumption.

To provide a compact positivedisplacenient pump assemblage'oi relatively large capacity, which may (be manufactured and sold at modera'tecost, and wherein the wear and tear has minimum deteriorating eflect.

be'lo provide a compact liquid pump which may parts of which are conveniently accessible for These and other specific objects and advan .the following detailed description. H 1 a A clear conception of embodiments of the various improved features constituting this invention, and of the mode of constructing and of operating rotary positive displacement pumps built in accordance with the improvement, may

which is relatively leakproof even when operat- 'ing upon relatively thin, oily or greasy liquids a1." fimple pump structure which can 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 several views.

Fig. 1' is a part sectional side elevation of. one of the improved pumps, .the section taken longitudinally and centrally through the structure;

Fig. 2 is an end elevation of the pump of Fig. i, with a portion of the end closure'orcover broken away to show the pump interior; and' Fig. Bis anexplodedor partially dismantled perspective view of one of the rotor,'-shaft and" sealassemblag'es. 7

While the invention has been shown and described herein as having beenfenibo'd'iedin a specific type of rotary positive displacement pump especially adapted for-usein the dairyand ice cream industries, it is not the intent tojthereby unnecessarily restrict the scope, since some of the improved features are obviously susceptible of more'general application.

Referring to the drawing; the improved pump assemblage illustrated therein comprises in general a main pump housing or easing 5 having therein interoommunicable displacement chambers t with which inletand outlet conduits l are directly communicable; a removable end closure plate or cover 8 coasting with a plane end face of the casing 5 to normally enclose the chambers t; a pair or similar ooacting positive displacement impellers 9 concealed and retatable within the chambers .6; laterally separated parallel rotor shafts H, I! jo'urnalled for rotation within bearings l3 formed integral with ,the casing t and having splined ends ll coacting wit-h grooved central bores i5 formed in the hubs is or the impellersW, l0 respectively; an

I improved packing or sealing assemblage enacting with each of the shafts ll, I! at its point of exit or projection from wi-thin the casing I; a pro- 1 pelling or driving shaft H, 12 journalled in anti-friction bearings iii,

- 19 mounted in inner and'outer gear casings 20,

2| 'respectively, the former of which is rigidly attached to the pump casing 5' and the latter of which is removably secured to the inner gear casing 20; sleeve couplings 22 connecting the driving shafts ill with the adjacent'alined ends of the rotor shafts l I, I2; and motion transmitting gears 23, 24 removably secured to the shafts I! by means of Woodruff keys 25 and intermeshing with each other to impart simultaneous but opposite rotation to the impellers Q, Hi when power is applied to the projecting end of the upper driving shaft ll. The main pump casing 55 and bearings l3 are preferably formed integral, but the bearings: l3

maybe provided with wearing bushings if so desired, and the inner gear casing 2d may be firmly attached to the end-of the casing 5 remote from the cover 8, by means of dowel pins 26, or otherwise. ings 5, Ellis preferably open at the opposite sides so as to permit freeaccess to the rotor shaft seals. and to the couplings 22.- Since the improved pump is operable in either direction and;

is therefore reversible, either of the conduits l may beutilized either as an inlet or outlet, and the conduits i which are formed integral with the casing 5 are threaded or otherwise formed for convenient attachment to the fluid conducting pipes of thesys'tem with which the pump i cooperates.

The displacement chambers 6 within the main casing 5 are of generally semi-cylindrical shape,

and the lobes of the impellers 9, it are formed to snugly engage the surfaces bounding the cham bers ii and the casing bearings l3 with minimum clearance. The coacting corners of the casing 5 f and of the impellers 9, iii are preferably slightly rounded as shown, in order to prevent'undesirable accumulation of solids in these comers, and also so as to facilitate cleaning, this being an important feature. The impellers 9, ill besides being firmly drivingly connected to their respective shafts ll, l2 by means of the splined endsw.

are retained upon these shafts by end collars 27 which may be rigidly attached to the reduced shaft ends in any suitable manner. closure or cover 8 is provided with bored pockets 28 formed for snug reception of the, rotor hubs I6 and collars'2'l, andthese bores provide bearings for the impellers 9, l and are also rounded at the corners which coact with the rotors so as to'prevent accumulation of solids and to fa- 'cili-tate cleaning. The cover 8 is adapted to be removablyattachecl to the plane end face of the pump casing ,tosn'ugly confine the impellers 9, l0 in operative condition, by means of wing nuts 29 coacting with studs 30 secured to the main casing 5. Theexternal surfaces of the housing elements including the casing 5, cover 8, and gear casings 20, 2| are also preferably rounded at all convex and concave comers so as to prevent accumulation of dirt and to facilitate cleaning, thereby providing an. extremely sanitary assemblage. V i

The improved. packing 'o'r. sealing assemblages which are provided at the points of protuber- 'ance of" the rotor shafts ll, [2 from the casing 5, are of like and interchangeable construction, and are freely accessible through the large side openings communicating with the space between the .casings5, 20. Each ofv these seals comprises The end I for each rotor shaft a coil spring 3| confined within a bore 32 in the casing 5 and coaoting with-this casing and with a metallic seating ring 32' which coacts with one side of a pliable packing ring 33 slidably confined in the bore 32; a non -rotary ring 34 embracing the rotor'shaft and'supporting the rings 32, and having pins 35. coacting with slots 36 in the casing 5 so as to prevent rotation of the ring 3d while permitting slight displacement Y thereofalong its own axis; a tapered sealing ring 3'l coacting with the plane and face of the ring 36 and having peripheral notches 38; another oppositely tapered sealing ring 39 spaced from the ring 36 and having peripheral pins 69 slid- The space between the eas jections 46 of'the couplings 2 2 coact'and the able with the projections $6 to complete the driving connection. The packing assemblage is obviously such that the. spring 3! will constantly urge the corresponding pump impeller 9, ill and shaft ll, l2 into snug contact with the casing v 5 and away from the cover 8, and when the end cover 8 and the-retaining elements 'Mare re moved and the springs 3i are released, the impellers 9, ill with their supporting and driving shafts ii, I2 may be slid freely and axially from -within the casing 5, "and the sealing elements are no longer locked and will permit free withdrawal of the shafts H, l2 therefrom aswlll be evident from Fig.3. I,

The gear housingsmr casings 20, 21-, are detachably interconnected by means of cap screws B8, and form a gear enclosing chamber 49 which. may be supplied with suitable lubricant such as grease. The ball or other anti-friction bearings l8, IQ for the driving shafts "are exposed to driving shafts ll also have grooves 4'! engagethe chamber 49, and in order to prevent escape of Iubrlcant the casing 2|] lsprovided with' a packing 50 adjacent the bearing l8 and meet-- ing with the sleeve-coupling 22, while the closure casing 2i .is provided with a similar packing 5i embracing the driving shaft H which projects out'wardly therebeyond.' Power may be applied to the projecting driving shaft H from any convenient source, and the motion transmitting 0 gears 23, 2d may be of any desirable type; and

- the'shafts H and gears 23,"24 are normallyretained in proper position and prevented from axial shifting-by means of spacer sleeves 52, 53 coacting with the inner races of the bearings f i8, I9 respectively and with the opposite faces of thegears. 'It is to be noted that all of the transmission elements are readily accessible upon removal of the cover casing 2i and the sleeves 52, 53 which positively preventaxial'displacement of the shafts l1 permit these shafts to ab- .s orb the end thrust exertedby the springs 3i upon the'alined rotor shafts ll, I2.

When the several elements of the pump have,

been properly manufactured, the structure may be readily assembled and dismantled at any time. The casings 5, 20 are normally rigidly united and aromas; 3

may then beinserted within the bores 32 over the ends of the shafts ll, ii. The spring seat- I 'ing rings 32 and pliable packing rings 33 may then be applied to the rings 34 and inserted within the bores "with the rings 32' in contact with the springs 3|, and the pins 35 should be caused to coact with the slots 36. The rings 31, 4i and 39 may then be applied to the shafts M, H in succession, andwith the pins 40 in engagement with the notches 38. The retaining elements 42 may thereafter be applied to the notches 43 of the shaftsv Ii. 52 by compressing the springs 3i suiflciently to cause the pins 40 to permit insertion of the elements 52. Upon subsequent release of the springs 3i, these springs will force the sealing rings 33, it into the position shown in Fig. 1 and the assemblage will thus be retained by the elements 42. The shafts it to which the gears 23, it are firmly attached'andwhich are 'rotatably supported in the bearings it, it are nxedagainst longitudinal displacement by the sleeves b2, 53; and when the springs 3i expand, I ,theycause the rotor shafts ii, i2 toenter the couplings 22 secured to the shafts i land to abut against the ends of thecorresponding shafts ii,

contact longitudinally along the bores 12 thereb' producing perfect sealing against escape of fluid longitudinally of the shafts II, II. The leakage fluid at-each packing cannot escape past the ring I! and therefore endeavors to escape between the bore of the ring 34 and the corresponding shaft ll, I2. The ring 31' coacting with the ring 34 however provides a sealed rotary joint which prevents escape of the leakage fluid between these rings, and the pliable packing ring M which is compressed by the spring 3| betweenthe sealing rings 31, vents escape of the leakage fluid beyond the ring it. The seating rings 32' serve to equalize and to distribute the spring pressure upon the pliable rings 33 with which they coact, and thus produce uniform expansion of therings t3 and of 1 the sealing assemblages. -It will thus be noted that the improved seals will eflectively prevent escape of any fluid from within the chamber 6,

and the construction of the packing elements is obviously such that no churning of liquid which may escape into the bores 32, can possibly occur. The packing rings 38, t4 and the spring 3i do not rotate, and the rotatable rings 31,

39, M have no protuberances which will tend to churn the fluid engaging the same. The sealing assemblages cooperate with the rotor shafts ii, 02 and impellers d, it to prevent undesirable wear on the other faces of the rotors, and

the wear on the inner rotor faces and on the rings t8, 3! is automatically compensated for by the springs-ti which do not rotate.

The packing elements may. however be readily removed over the ends of the shafts ii, it when 39 positively prei the gear and drive shaft assemblage, the cover 401mg maximal opemiflfln' The ends of the shafts j'these ends are withdravmvfrbm he couplings Edi and the seals also eliminate wear in these cou- 'plings by eliminating grelative movement between theatts M, ii afidthe, coupling sleeves durthereby completing the driving connections. Dismantling of the assemblage may be readily accomplished by merely reversing the assembly operations, and if it becomes necessary to dismantle casing it may be removed.

During normal operation of the pump, power a may be applied to the outer end oi the protrud mg shaft iizto cause the gears 33, 2d, toultaneously rotate in opposite directions. While the primary driving shaft ill will transmit rotating motion directly to the pump impeller d, simultaneous but opposite rotation will be imparted to the other pump impeller iil'through the gears it, it and the other driving shaft-ill. Depending upon the direction of rotation of the driving shaft ii, the impeller '8, it, may cause fluid to be drawn through one of the. conduits i and delivered through the other conduit. While the general type of impellers d, it, used in the pump areold and wellknown, it is an important featurepf the present invention that the corners of ,the-impellers t, it are rounded and onset with the'rounded corners in the casing b and cover d. This rounding will obviously initially prevent undesirable accumulation of solids in these corners, and will permit thorough cleaning of the corners when the structure is dismantled. pumps of this type are used to propel greasy liquidssuch as milk and cream and the improved pump may therefore bereadily maintained in sanitary condition. 7

When the pump is operating normally, any leakage fluid under pressure which escapes from the chamber 8 along the shafts it, it, will tend to escape through the chambers formed by the bores 32. The compressionsprings 3iv coacting with the seating rings 32" and with the pliable rings a will force these rings a: into intimate 6 This is extremely important when M, ii remote from the impellers 9, id have no outward projections, and the driving connection is obtained by'the use of recesses t5 coasting with inward projections 36 on the sleeve couplings 22. While the U-shaped retainers d2 pro vide suitable means for holding the sealing assemblages in place during normal operation, these retainers may obviously be formed integral with the adjacent rings 39 and secured to the shafts w H, idby locking means other than the slots M,-

such as radial pins coacting with lateral inclined extensions of the shaft grooves M. The

impellers d, it and the shafts M, it cannot, however, be removed without first releasing the lock- 55 ing retainers, and the-shafts H and gears 23,

2d are not disturbed by removal of the impellers.

The transmission gearing may obviously be abundantly lubricated and is normally effectively confined within the casing til, it, but may be rem moved if necessary. Escape of lubricant from the transmission chamber it is positively prevented by the packings it, iii and the gears 23,

M as well as the shafts il'll are prevented from shifting endwise by the two sleeves east and s5- gears 2t, 2t coacting with the bearings id, it.

From the foregoing specific description it will be apparent that the present invention" provides an improved pump assemblage which is simple,-

compact and durable in construction and which is highly eflicient and sanitary in use. All parts .of the assemblyare conveniently accessible for cleaning and inspection, and by virtue of the fact that'all parts, of-one pump impeller assemblage are interchangeable with similar parts of the other, the-cost of construction and assemtive l y preventing rotation of said non-rotary ring blage may be reduced to a minimum. The improved pump is obviously eflectively sealed against possible escape of liquid by emcient packings coacting with the shafts ll, l2, and these sealing devices also reduce wear to a minimum and may be readily assembled or removed and cannot churn liquid which comes in contact with the elements thereof. The various elements of the assemblage are so constructed that the pump cannot possibly be improperly assembled, and

- the device may therefore be dismantled and re- The improved pump.

assembled by a novice.

and an enlarged bore adjoining said bearingassemblage has proven highly satisfactory in ac- V tual commercial use, and is obviously .especiall applicable to the dairy industry.

It is to be understood that it is not desired to limit this invention to the exact details of construction or to the precise modevof use, herein shown and described, for various modifications within the scope of the claims may occur to persons skilled in the art.

I claim:

1. In combination, a'pasing having a bearing and an enlarged bore adjoining said bearing opening outwardlyoffthe casing, a shaft journalled in said bearing and extending outwardly of said casing through and beyond said bore and having diametrically opposite transverse notches therein remote from the open end of said bore,

a U-shaped retaining element slidably coacting with said shaft notches to fixedly secure the element to said shaft, said element having peripheral grooves extending longitudinally of said shaft, an outer rotary ring embracing said shaft between said element and said bore and having driving pinsprojecting from the opposite sides of. the ring and coacting with said element grooves, an inner rotary ring embracing said shaft between said outer ring and said bore and having peripheral recesses slidably and drivingly engaged by said'pins, an inwardly distortable pliable packing snugly embracing said shaft between said rings, a non-rotary ring slidably confined within said bore and having an end face in sealing engagement with the adjacent end face of said inner rotary ring, means for posi- .gagingsaid bore, and resilient means within said bore and coacting with the bore bottom and with said outwardly distortable packing to distort said packings. and to: urge said rings toward each other-and against said element.

2. In combination, a casing having a bearing opening outwardly of the casing, a shaft journailed in said bearing andextending outwardly of said casing through and beyond said bore and having diametrically opposite transverse notches therein remote from theopen end of said bore, a U-shaped retaining element slidably coacting with saidshaft notches to fixedly secure the element to said shaft, said element having peripheral grooves extending longitudinally of said shaft, an outer rotary ring embracing said shaft between said element and said bore and having driving pins projecting from the opposite sides of the ring and coacting with said element grooves, an inner rotary ring embracing said shaft between said outer ring and said bore and having peripheral recesses slidably'and drivingly engaged by said pins, an inwardly distortable pliable packing snugly embracing said shaft between said rings, a non-rotary ring slidable within said bore and having a plane, end face in sealing contact with the adjacent plane end face of said inner rotary ring, radial projections carried by said non-rotary ring and slidably engaging said casing to positively prevent rotation of said non-rotary ring while permitting free sliding thereof along said bore, an outwardly distortable pliable packing carried by said non-rotary ring and snugly engaging said bore,

and a spring embracing'said shaft within said LEROY ALBERT THOMSON.

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