US 3046900 A
Description (OCR text may contain errors)
July 31, 1962 A. POLLAK 3,046,900
SUBMERSIBLE SUMP PUMP ASSEMBLIES Filed Jan. 2. 1959 2 Sheets-Sheet 1 ///T i i I I I Z; GU62 ENTOR.
July 31, 1962 A. POLLAK SUBMERSIBLE SUMP PUMP ASSEMBLIES 2 SheetsSheet 2 Filed Jan. 2. 1959 United States Patent Office 3,fidfi,%fi Patented July 31, 1962 3,046,900 SUBMERSIBLE SUMP PUMP ASSENBLIES Abraham Pollak, Linfield, Pa. Filed Jan. 2, 1959, Ser. No. 784,789 3 Claims. (Cl. 103-87) This invention relates to improvements in submersible sump pump assemblies.
Submersible pumps require a seal at the place where the rotating shaft terminates and the operative sealing members that must be kept water-tight. This sealing has been conventionally accomplished by the use of what is known as a mechanical seal. Such mechanical seals now comprise standard articles of commerce and are being manufactured and generally used in the pump-manufacturing business, and in the pump assembly of my invention hereinafter described I also embody a mechanical seal.
One of the objects of this invention is to produce a pump assembly which difiers from those of other assemblies in that another or second seal is also utilized in combination with said mechanical seal. Reasons for such use are twofold: (1) sump pumps are most commonly used with dirty Water embodying gritty material. The mechanical seal hereinabove referred to has two lapped faces which run together and provide the sealing action. If these surfaces become pitted or scarred they will leak. The gritty matter in the water mentioned above is likely to cause this pitting of the mechanical seal; (2) the mechanical seal must be kept lubricated and is designed for lubrication by water. This type of pump is provided at its lower end with an impeller having on its upper surface a series of volute or spiral ribs extending from the outer edge to a central eye portion and the mechanical seal is normally located directly above the eye of said impeller. When the pump is at rest, there is adequate water covering the mechanical seal and adequate lubrication is thus provided. However, when the pump is in operation, a centrifugal pump impeller draws water into its eye. The impeller thus diverts a good portion of the water away from the mechanical seal and consequently there is provided less than adequate water lubrication.
An important feature of my invention is therefore, in effect, to further seal the mechanical seal. This eliminates the defects of pitting and providing of inadequate lubrication hereinabove mentioned.
With these and other objects in view, the invention comprises the combination of members and arrangement of parts so combined as to coact and cooperate with each other in the performance of the functions and the accomplishment of the results herein contemplated, and comprises in one of its adaptations the species or preferred form illustrated in the accompanying rawings, in which:
FIG. 1 is a view in perspective of a pump embodying my invention;
FIG. 2 is an enlarged vertical section of the pump shown in FIG. '1;
FIG. 3 is an enlarged side elevation of a strainer element shown in FIG. 1 and employed in my said pump;
FIG. 4 is a bottom plan view of the strainer element shown in FIG. 3 showing the means for holding the parts together; and
FIG. 5 is a section on the line 5-5 of FIG. 2.
In the embodiment of my sump pump illustrated, 10 indicates a motor casing provided at its lower end with an integral bearing member 14) and having a shaft 10 that has an operative connection with an impeller 11 and a sealing combination known as a mechanical seal is normally located on the hub of the shaft 10 above the eye of the impeller 11. Said eye comprises that part of the impeller 11 at the inner central end comprising the terminal portions of the spiral impeller ribs. The spiral ribs of the impeller extend from the outer edge to said central eye portion. Thus, the motor 10 is provided with a shaft 13 and said shaft is provided at its lower end with a shaft-extension 12, and it will be noted that all of the sealing members are located inside a hub-housing 13 surrounding said extension 12 of the motor shaft 10 which comprises, in effect, a holder housing at the hub surrounding said motor shaft-extension 12.
Now, beginning at the lower end of the motor shaft extension 12 where any leakage would begin my invention embodies the following: A standard lip seal 14 is impressed into the housing 13. Above said lip seal 14 I have provided an oil soaked felt packing 15 which is substantially in thickness. Above this packing 15 I provide a phenolic washer 16 and a snap ring 17. The snap ring 17 positions the various members in the housing and also eliminates a condition met in earlier designs wherein it was necessary to machine this volute from two ends. Above the snap ring 17 is a second phenolic washer18 and above this second phenolic washer 18 are two pieces 19 and 20 of the standard mechanical seal, one of which, as for example the piece 19, is fixedly mounted in the outer cylindrical housing 13 and the other member 20 is rotatably mounted on the shaft extension 12. A collar 22 is fastened to the shaft extension 10 by a set screw 22 and is also positioned above the mechanical seal member 20.
There is, however, an air space surrounding the upper portion of this upper member of the two piece mechanical seal, and it is in this space 21 that we pack a large quantity of highly lubricating grease which acts as a lubricant for the running faces of the mechanical seal. Tests show that enough lubricant may be provided in this chamber 21 to produce adequate lubrication for the mechanical seal members 19 and 20 for ten to fifteen years of the normal running life of the pump. I therefore not only provide additional sealing members to seal the mechanical seal in this assembly, but I also overcome the two defects hereinabove specified. In my improved assembly, in order for water to reach the motor which is the member that must be kept dry, such water must first pass through the standard lip seal 14, then through the felt packing 15, then through the washer assembly 15, 16 and 17 and finally through the mechanical seal members 19 and 20. The mechanical seal alone is suflicient to provide basic sealing, but my design provides both a second seal and an adequately-protected mechanical seal.
it will be understood also that if any water does get as far as the mechanical seal, it will by virtue of having had to pass through so many elements which act :as a labyrinth be very clear water and such water could in no way have gritty particles which would sear the faces of the mechanical seal.
Another feature of this invention is that this pump is designed to use a standard motor as the source of power. Motor parts have heretofore been built into the upper and lower casings. Such constructions, however, are more expensive than the use of a standard motor and, of course, such constructions present a problem to the consumer or purchaser in case the motor should f ail. On the other hand, if the motor should fail in the case of my pump, it would be a simple matter to remove said standard motor and replace it with another motor of standard construction.
In the preferred embodiment of my invention. the impeller hereinabove referred to is encased within an impeller housing 11 and is provided on its upper surface with a series of spinal elements extending from its outer edge to a central eye portion. The motor shaft hereinabove specified extends to the center of this eye portion and has an operative connection with said impeller to cause water to be drawn into the eye thereof. The casing completely encloses the said impeller except at its eye portion and is provided above said central eye portion with a series of water entrance apertures 11 which surround said eye portion and upon the operation of said impeller by said motor shaft cause the passage of water therethrough and into said impeller eye.
In said preferred embodimentof my invention, the said aperture casing at said water entrance apertures surrounding said impeller eye portion is "provided with a removable strainer fitting around said shaft and mounted above said water entrance apertures. Said strainer comprises a metallic strainer element 23 with apertures 23 all around the periphery thereof and when assembled comprises a cylindrical member having a round or circular base of wide diameter for resting on a horizontal part of the casing and a top member of reduced diameter for abutment against the shaft-enclosing member 13.
Said strainer element is provided around its entire periph- 7 cry with a series of strainer water-entrance apertures extendingthrough the same to cause water which is passed therethrough in said water entrance apertures to be strained and thus to avoid the entrance into said apertures of any large pieces of material which are of greater size than the entrance apertures.
In said preferred embodiment of my invention the said strainer is removably mounted on said casing and is formed in two parts which are connected together in'the manner of a hinge by the use of a spiral spring, it being understood that the metallicstrainer comprises a twopart rim member 24, 24 each composed of a semicircular rim section and :one of said parts is provided with a pivot portion comprising a semi-cylindrical member 25 which fits into a hollow semi-cylindrical pivot bearing portion 25 both pivot and beating portions being formed integrally in the metal of the strainer, and such pivotal portions are combined with a spring 26 which is stretched between the two parts of the strainer and connected at its opposite ends to pins 26, 26 fixed in said strainer parts. This arrangement of the parts and spring is adapted to permit spring-pressed pivotal movement and alignment,
about the pivot part 25 and provides for opening and closing movements of the two partsof the strainer to permit attachment and removal from the pump. In the preferred form of my invention the strainer is also provided with a pivot structure comprising a secondary holding pivot 27 and pivot bearing 27 which are disposed at the edge of the strainer opposite to the operative pivot and bearing 25, 25 This secondary spaced pivot 27 and bearing 27 enable the two parts of the strainer to be aligned and held in alignment with each other and enable the two parts to be more securely closed and held in closed position by its spring-actuated element. The initial pivoted connection and the interengaging secondary holding connection of the secondary holding pivoted elements permit ready and quick mounting of the strainer over the casing apertures and also enable a ready demounting of the strainer for cleansing purposes. V
Operation of means described for providing a secondary or further seal for the conventional mechanical seal to eliminate pitting by gritty matter and to provide adequate lubrication will be obvious and the above and other features of my invention hereinabove particularly described will likewise be obvious. Other elements, however, such as the switch 28 and the floats 29 and 30 for actuating said switch comprise structural elements and have no bearing on the inventive elements herein set forth and operation of such structural elements is conventional and need not be further described.
Having described my invention, I claim:
1. In combination with a submersible pump having a mechanical seal. a
' d rotatable pumping element, a casing forming apumping chamber surrounding said pumping element and a drive shaft for effecting rotation of said pumping element, a 9
seal construction including non-rotatable means surrounding said shaft having an oil impregnated fibrous member in sliding sealing engagement with said shaft and located with one face thereof exposed to the pressure produced by said pumping element to provide a principal sealing action and effect filtration of fractional flow past said fibrous member, and a second sealing'member disposed in axially spaced relation from said fibrous member and including two relatively rotatable means one of which is operatively secured to said drive. shaft and in operative sliding sealing engagement with an opposed complemen tary surface of the other said means to impede fluid pas-. sage of said fractional flow, said seal construction includ: ing a recess defined at least partially by said sealing means in proportion to receive lubricant for effecting anti-friction sliding relation between'said two relatively rotatable 2. A submersible sump pump which comprises animpeller member provided on its upper surface with impeller blades extending outwardlyfrom a central eye space and having an upwardly extending impeller drive shaft for eifecting pumping action by said impeller blades, a motor above said shaft and connected to drive said shaft, a casing having a hub portion enclosing said impeller shaft, a grit intercepting seal in said hub portion comprising an oil impregnated fibrous packing in sealing engagement 7 with said hub portion of said casing and exposed to the output pressure developed by said impeller shaft to seal against the passage of grit and water, and a mechanical seal located to receive the flow which is filtered through said fibrous packing and provide a barrier against such flow reaching the motor between said grit' intercepting seal and said motor said pump having a lubricant supply space between said mechanical seal andsaid hub portion of said casing and in communication with said mechanical seal.
3. A sealing means fora sump pump having an impeller and a motor driven shaft, which comprises a casing for said. impeller having a hub portion to enclose said shaft, a mechanical seal between said hub portion and said shaft, and a grit intercepting seal between said hub' portion and said shaft and between said impeller and said mechanical seal, said grit intercepting seal comprising a packing of oil. impregnated fibrous material disposed in sealing relation with said hub portion of said casing and said shaft said sealing means having a space for lubricant between said hub portion of said casing and said mechanical seal in communicationwith said References Cited in the file of this patent UNITED STATES PATENTS 1,849,404 Leonard Mar. 15, 1932 1,866,551 Durdin July 12, 1932 2,092,237 Antonelli et a1. Sept. 7, 1937 2,430,509 Hoover Nov. 11, 1947 2,480,417 Muhly Aug. 30, 1949 2,505,868 Murphy May 2, 1950 2,766,696 Lung Oct. 16, 1956 2,794,399 Murphy June 4, 1957 2,815,717 SZwa-rgulski et a1. Dec. 10, 1957 2,854,927 Berg Oct. 7, 1958 2,856,858 Purcell et a1. Oct. 21, 1958 2,862,452 Lung Dec. 2, 1958 2,867,173 Lung Jan. 6, 1959