US2848952A

US2848952A - Pump construction

Info

Publication number: US2848952A
Application number: US358263A
Authority: US
Inventors: Alden H Wakeman
Original assignee: Creamery Package Manufacturing Co
Current assignee: Creamery Package Manufacturing Co
Priority date: 1953-05-29
Filing date: 1953-05-29
Publication date: 1958-08-26
Anticipated expiration: 1975-08-26

Description

Aug. 26, 1958 A. H. WAKEMAN PUMP CONSTRUCTION Filed May 29, 1955 6% KWMW W Mn MM 2 United. States Patent. (1

. I Patented Aug. 26 195'8 2; pumpedthrough the pump housing 11 be' free from any deleteriouszsubstance: which might find' its way into the 2 848 interior of said housing and contaminatethe product. The

PUMP CONSTRUCTION Alden H.Wakeman, Lakemills, Wis assignor to. The Creamery Package Mfg. Company, Chicago, 111., a corporationof Illinois Application May 29, 1953, Serial No. 358 263...

2 Claims.- (Cl; 103-126) This inventionrelates to a pump-and more particularly to a positive pump whereinit is important that: the interior thereof be free from any deleterious substance which might contaminate a product .while:being:pumped therethrough.

The problem of sealing the' periphery of? the shaft of'theimpeller in a pump of this type againstsubstances such as air, oil and the like beingdrawn into .thesuction side of the interior of the pump housing and contaminating theproduct being pumped, has notheretofore' been successfully overcome by use of the packingmaterials which are presently available. Various attempts have heretofore. been made to overcome this problem, butbecause of the cost, complexity, and bulkiness of construction and the ineflicient operatiomof-the resultantpumps, such attempts have met withonly partial success.

It is .one of the objects, therefore, of this inventionto provide a'pump wherein the possibility of a deleterious substance beingdrawn intothe interior of the pump-casingv fromaround the periphery of the. rotatingimpeller shaft has been completely eliminated.

It is a further object of this invention-to. provide a pump wherein the product being pumped, while. under high dischargepressure, functions as the sealing means asrwellas the lubricant for the impeller shaft seal. and the impeller itself.

It is a further object of this invention" to providesa' pump which is simple and compact in construction, efiicient in operation, andiminimizes: service and maintenance: costs.

Further and additional. objects will appeart-from uthe description, accompanying drawing, and. appendedzclaims.

In. accordance with one embodiment of 'this invention, a' pump is provided: comprising a: hollow r casing; having an inlet: port and an. outl'etaport, and: a pair of impellers rotatably mounted within; said; casing. and: disposed. intermediate said inlet and outlet L ports. The periphery: of each: impeller isldeformed *andhasvportions thereof: in contact with. the: interior of the casing. and the. other impeller; The side surfaces-of the. casing. interiors cooperate with the adjacent'endrfaces of: each impeller. to

. shaperofthe'nubs. may vary without departing. from the form-azcavity-which encompasses the axis v.of; the impeller and is 'disposedintermediate said 1 axis and ;the periphery of said impeller. The encompassingzcavity communicates with theoutletport of. said.v hollow casing to permit: a portion of the product being pumped under highl'pressure to completely fill such cavity.

For a: more complete understanding of: this invention reference 'shouldnow be made.- to .therdrawing wherein:

Figure- 1 is a vertical sectional view of-thepump;

Fig: 2 is a: right side. elevational view' of-the pump taken along line :2-2 of Fig. 1; .and

Fig. 3 is an enlarged. fragmentary. sectional view: of the-cavitieswformed between-the end faces of the impellers and, the adjacent side: surface of'thecompartment.

Referringnowto the drawings and more'particularly to Fig.. 1, apositive pump 10 is-..shown:. for usewins'instances where it is important that the product being pump housing 11-1 comprises two-compartments, 12 and 13, formed: in the: interior thereof which are separated .16 formed: in* one side of the compartment and is discharged through outlet port 17 formed in the opposite side of the compartment, see Fig. 2'. In this instance, impeller 14 is the driven. impeller and has the shaft 18 thereof, which. extends through an aperture formed in partition 13f, rotatably 'supported withinthe housing 11 by. a. pair of anti-friction bearings 20' and 21 arranged in; axially spacedrelation; One end 18w of shaft 18 projects outward from. housing 11. through a suitable opening: and is adaptedto be driven by some external source of; power, not shown. Keyed: to shaft 18 and disposed;within compartment 13 is'a spur gear 22 which is adapted. to meshs with. a like spur gear 23, the latter beingkeyeditoxshaft 24' for i'mpellerlS, to effect simultaneousirotation of the twoimpellers. Shaft 24 likewise extends: through. asecond opening formed in partition 13" and 'is enclosed entirely within housing 11 and is supported by-apair of-uax-ially spacedanti-friction bearings 25' and 26; Compartment 13 is normally filled or partially filled with a lubricant which may be introduced into. the: compartment through a.- conduit, not shown,

.upper'side" of compartment 13. Both

shafts

18 and 24 are surrounded by sealing rings 30 and 31, respectively, which: arexdisposed between anti-friction bearings 21.1 and 26 and the. partition-13, see- Fig. 1

Each of: the'impellers 14 and'=15: is of like construction and comprisesa metallic. hub or core 32 which has the outer :periphery'thereof shapedso as'to form a plurality of symmetrically arranged radially extending nubs 33 Whichtare adapted:to=mesh with one anotherand impel the. productfrom. the low pressure side 12a to-the high pressure sideh12b' of: the compartment. The. number and scopeof.the-invention; The: core 32" is provided with a center bore,32a which is internallysplined and adapted to receive: the, splined= end 18b or. 24b' of the shaft 18 on 24, respectively.. Encompassing the outer periphery ofrcore 32, including the end faces. 32b thereof except for a. portion; surroundingthe center bore, is a plastic covering 1 3,4: ofpreferablyxrubber' or latex material which is notcorroded by or; does'not: contaminate the product being pumped.- and klikewise is. possessed; with good; wearing qualities. The nubs-33 of. the core 32 with. the covering 34' thereon are of such dimension that the outer ends 'thereof contact the: annular peripheral surface 37 of thecompartment 12, asseen more clearlyin EigrZ. The portions 34a of the coating'34 which sub 'stantially cover the end faces 32b: of core 321 are'provided; with? a marginal. boss 3412. which, in this instance, conforms substantially -to the perimeter. of nubs 33; The marginal boss. 34b is adapted to slidably engage the opposing side surfaces 35 'and%36-Of the compartment 12 when; the impellers. are being rotated. The area delimitediby thewbosson each of the endfaces 32b of'the impellerszformsva. cavity 43. which; is adapted to encompass the periphery of shaft 18: or 24.

Formed: within. each. of the side. surfaces 35? and 36 of. compartment 12: are elongated grooves-38 and 40, respectively, which are disposed Within the high pressure side 12b of the compartment 12. The ends of each

groove

38 and 40 are adapted to communicate with the cavity 43 formed in each of the end faces of the

impellers

14 and 15. A portion of each

groove

38 and 40, disposed intermediate the ends thereof, is adapted to communicate with the high pressure side 12b of the compartment 12. The purpose of

grooves

38 and 40 is to allow a portion of the product, being pumped through compartment 12, to find its way into the cavities 43 and surround the peripheries of the

impeller shafts

18 and 24 with the product under high pressure. It will be noted in Fig. 1 that an annular recess 44 is formed in the side surface 36 of compartment 12 and is adapted to encircle the periphery of the

impeller shaft

18 or 24. Disposed within each of the recesses 44 is an annular sealing piece 45 which is substantially V-shaped in cross-section. The open side of the sealing piece 45 is adjacent the end face of

impeller

14 or 15 and is adapted to communicate with the cavity 43 formed between the end face of the impeller and the side surface 36 of the compartment. Upon the high pressure product becoming entrapped within the cavity, the product will cause the annular sealing piece 45 to expand a certain amount, thereby causing the piece 45 to function more effectively as a seal for the impeller shaft. By reason of the fact that the product under high pressure is disposed within the cavities adjacent each of the end faces of the impeller, an effective seal is provided which prevents any foreign or deleterious substance such as oil, air and the like, being drawn into the suction side 12a of the compartment around the periphery of each of the shafts. Furthermore, the product disposed within each of the cavities 43 acts as a lubricant between the end faces of the impellers and the corresponding side surfaces 35 and 36 of the compartment 12. The compartment 12 has one side 41 thereof removable to facilitate assembly of the impellers within the compartment 12. The cover 41 is secured to the housing or casing 11 by nut and bolt assemblies 42.

It is to be understood, of course, that the peripheral shape of each of the impellers may be varied without departing from the scope of this invention and that the marginal boss 34b may be of any shape so long as it encompasses the impeller shaft and is spaced therefrom and in addition is disposed entirely within the periphery of the impeller. Furthermore, if so desired, the end faces of the impellers may be fiat and a boss, corresponding to the marginal boss 34b, be formed instead on the side surfaces 35 and 36 of the compartment. In this latter instance, however, the bosses would have to be of such a shape that they would be disposed at all times within the outer periphery of the impellers and spaced from the periphery of the impeller shaft. Thus, each side surface of the compartment would have formed thereon a boss for each impeller. The area delimited by the boss would communicate with the high pressure side 12b of the compartment 12 through a groove or any other suitable conduit. While the pump in this instance is directed to a unit containing two impellers, it is not to be limited thereto, as the novel construction may be incorporated in a pump having one or more impellers as well as single or multi stages.

Thus, a pump has been provided which is simple and compact in construction, durable and efficient in operation, and eliminates completely the possibility of foreign or deleterious substances finding their way into the interior of the pump casing from around the periphery of the impeller shaft and contaminating the product being pumped. Furthermore, a pump has been provided which utilizes the product being pumped to provide a seal for the impeller shaft and to provide a lubricant for the end faces of the impeller.

While several embodiments of this invention have heretofore been described, it will be understood, of course,

,4 that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

I claim:

1. A pump for circulating a liquid product, comprising a casing provided with a chamber, an inlet port through which such product enters said chamber, and an outlet port through which such product leaves said chamber at a higher relative pressure; an impeller rotatably mounted within said chamber and disposed intermediate said inlet and outlet ports, said impeller having a peripheral configuration formed by a non-uniform radius about the rotary axis of said impeller and portions of said periphery being in slidable contact with said chamber surface to impel such product from said inlet port to said outlet port, an end face of said impeller being provided with a resilient peripheral boss conforming to the contour of said impeller periphery and in substantially continuous slidable engagement with the adjacent chamber surface and forming a cavity encompassing the rotary axis of said impeller and occupying a substantial portion of the area of said impeller end face; conduit means provided on said casing and communicating with the outlet port of said casing and said cavity and effecting entrapment within said cavity of a portion of the discharged product, the entrapped product being at a substantially uniform pressure throughout said cavity and effecting lubrication between said end face and the adjacent chamber surface; a drive shaft for said impeller protruding from said end face and extending through a suitable bore formed in said chamber surface, the end of said bore adjacent said chamber surface being provided with a counterbore in partial overlapping and communicating relation with said cavity; and a liquid pressure-responsive, shaft-encompassing element engaging the periphery of said shaft and disposed within said counterbore and being deformable by the liquid pressure within said cavity to effect a liquid seal between said shaft and said bore.

2. A pump for circulating a liquid product, comprising a casing provided with a chamber, an intake port through which such product enters said chamber and a relatively spaced outlet port through which such product leaves said chamber at a higher relative pressure; a pair of impellers mounted within said chamber intermediate said inlet and outlet ports for rotation about substantially parallel relatively spaced shafts, each shaft extending axially from the corresponding end face of said impeller and through one of a pair of relatively spaced bores formed in the adjacent chamber surface, the end of at least one of said bores adjacent said chamber surface being provided with a counterbore, the peripheral configuration of each of said impellers being formed by a non-uniform radius about the impeller rotary axis, portions of said impeller peripheries contacting one another and the chamber surface, when said impellers rotate, to effect impelling the product from the inlet port to the outlet port, the end face of said impeller adjacent the counterbore being provided with a resilient marginal boss conforming substantially to the contour of said impeller periphery, said peripheral boss being in substantially continuous slidable contact with the adjacent chamber surface upon rotation of said impellers and forming a cavity encompassing the rotary axis of said impeller, said counterbore being in partial overlapping and communicating relation with said cavity, conduit means provided on said casing and communicating with said outlet port and said cavity and effecting entrapment in said cavity of a portion of the discharged product at substantially a uniform pressure throughout said cavity and effecting lubrication by the entrapped product between said end face and the adjacent chamber surface, the cavity-forming segment of said impeller end 5 face constituting a substantial portion of the area of said impeller end face; and a liquid pressure-responsive shaft-encompassing element disposed Within said counterbore and being deformable by the liquid pressure within said cavity to efiect a liquid seal between the encompassed shaft and the corresponding casing bore.

References Cited in the file of this patent UNITED STATES PATENTS 1,096,186 Nesmith May 12, 1914 1,451,859 Balcker Apr. 17, 1923 2,258,371 Wernert Oct. 7, 1941 2,455,194 Rumsey Nov. 30, 1948