US 2898861 A
Description (OCR text may contain errors)
Aug. 11, 1959 Filed April 8. 1954 A. H. WAKEMAN PUMP CONSTRUCTION 2 Sheets-Sheet 1 IN VEN TOR.
Aug. 11, 1959 A. H. WAKEMAN PUMP CONSTRUCTION Y 2 Shets-Sheet 2 Filed April 6; 1954 BY. AKA
PUMP CONSTRUCTION Alden H. Wakeman, Lakemills, Wis., assignor to The Creamery Package Mfg. Company, Chicago, 11]., a corporation of Illinois Application April 6, 1954, Serial No. 421,216
1 Claim. (Cl. 103-103) This invention relates to a rotary pump construction capable of being readily assembled or disassembled, when desired, and including a sealing assembly incorporated in the pump and disposed intermediate the pump housing and the portion of the impeller shaft protruding therefrom.
In the dairy industry, for example, various pieces of equipment, of which pumps, through which the product passes, are a part, must be disassembled to permit thorough cleaning thereof either daily or after each run of the product therethrough. In such pumps, particularly of the centrifugal type, a relatively stiff coil springis usually utilized in providing a seal between the periphery of the rotatable impeller shaft and the opening in the casing to accommodate the shaft.
Heretofore, in disassembling such pumps, the seal assembly or unit became completely disassembled as soon as the impeller was released from the pump shaft. Because of the force of such a spring it frequently resulted, if care was not exercised in disassembling, that the various parts of the sealing assembly were thrown oif from the shaft with such force as to create a hazard for the workman. Furthermore, because of the stiffness or resistance of the spring to compress-ion, difficulty in reassembling the pump and the seal assembly also resulted which caused delay in completing the cleaning operation. Due to the fact that such spring and several other parts of the seal assembly do not come into contact with the product, there is no necessity for disassembly thereof for cleaning.
Thus, it is a principal object of this invention to provide a centrifugal pump which can be readily disassembled for cleaning the parts contacting the product and which can be easily and securely assembled to continue operation.
It is another object of this invention to provide an effective pump seal for a dairy pump in which the parts thereof, which are not in contact with the product, will not become disassembled when various other parts of the pump are disassembled for cleaning.
It is a further object of this invention to provide a means for retaining a pump impeller on a shaft which can be quickly and easily attached to the pump shaft when the impeller is in position on the shaft and when so attached will be secure and incapable of being inadvertently detached.
It is a further object of this invention to provide a pump seal assembly which will greatly facilitate cleaning of the pump.
It is a still further object of this invention to provide a pump which is simple in construction, effective in operation, and inexpensive to produce.
Further and additional objects will appear from the States Patent 2,898,861 Patented Aug. 11, 1959 ICC description, accompanying drawings, and appended claim.
In accordance with one embodiment of this invention, a pump construction is provided comprising a hollow casing, a rotatable impeller shaft having a portion thereof protruding from the casing through an opening formed in the casing, a spring-type retention clip for securing the impeller to the shaft, and a seal assembly carried by the protruding shaft portion and cooperating with the exposed circumjacent portion of the shaft opening in the casing. The seal assembly includes a compressible ring encompassing the protruding shaft portion and disposed in a fixed position adjacent said casing shaft opening, a sealing collar encompassing the protruding shaft portion and the compressible ring as well, the latter being in a state of compression when encompassed by the collar, a spring cooperating with the protruding shaft portion and the sealing collar to urge the latter into abutting, sealing, rotatable relation with the exposed circumjacent portion of the casing opening, and a retainer piece encompassing the protruding shaft portion and disposed intermediate the spring and the sealing collar. The retainer piece has the opening thereof, through which the shaft passes, of less diameter than the diameter of the opening of the sealing collar, through which the shaft likewise passes, and thereby limits the axial expansion of the spring to the point where the compressible ring is positioned on the shaft.
For a more complete understanding of the invention, reference should be made to the drawings wherein:
Figure l is a fragmentary side elevational sectional view of an improved centrifugal pump showing the novel sealing assembly thereof in detail;
Fig. 2 is an enlarged fragmentary side elevational view of the improved pump construction showing the means for securing the impeller shaft to the end of the pump motor shaft;
Fig. 3 is a side elevational view of the impeller shaft alone, having one end thereof cut away;
Fig. 4 is a sectional view taken along line 4-4 of Fig. 1;
Fig. 5 is a sectional view taken along line 55 of Fig. 2;
Fig. 6 is a fragmentary end view of the end of the impeller shaft showing the impeller and retaining clip in assembled relation therewith; and
Fig. 7 is an enlarged view of the novel retaining clip shown in Fig. 6.
Referring now to the drawings and more particularly to Fig. 1, an improved centrifugal type pump 11 is shown which is capable of being readily assembled and disassembled for cleaning, when desired. The pump 11 includes a pair of casing sections 12a and 12b which cooperate with one another to form a compartment 13 in which is disposed the rotatable impeller 14. Casing section 12a is provided with inlet and outlet ports 15 and 16, respectively, through which the liquid is caused to pass. Casing section 12b, on the other hand, is provided with an opening 17 through which extends the shaft 18 for impeller 14. Casing sections 12a and 12b are clamped together and, in turn, secured to a stationary motor cover 20 by a removable, expandable clamping ring 21. A gasket 22 is provided between sections 12a and 12b to provide a seal between the two sections. It will be noted in Fig. 1 that gasket 22 is provided with a bead 22a which is adapted to seat within a suitable groove formed in the abutting face of easing section 12b and prevent relative movement of the gasket with respect to the casing sections, when the latter are in assembled relation.
The impeller shaft 18, as seen more clearly in Figs. 1 and 2, has one end 18a thereof terminating within compartment 13. The end 18:: is reduced in size for accommodating the hub 14a of impeller 14. An annular shoulder 18b is formed on shaft 18 and is spaced axially from end 18a a predetermined distance. The shoulder 18b, when the pump is assembled, is disposedwithin the compartment 13 but adjacent opening 17, formed in casing section 12b, and is adapted to have a tapered side thereof abutted by the hub 14a ofimpeller 14, when the latter is assembled on shaft 18. The impeller 14 is held against shoulder 18b by a washer or ring. 23 which encompasses shaft end 180 and contacts the opposite side of the impeller hub. A spring clip 24, shown more clearly in Fig. 7, is utilized in this instance for retaining the washer 23 in contacting relation With the impeller.
The spring 24, to be described more fully hereinafter, has a portion thereof seated within ,an annular groove 18c, which prevents endwise movement of the spring with respect to shaft end 18a once it is in position thereon. The spring 24 is formed of a single piece of spring wire which is shaped to form an enlarged bight portion 24a and a pair of tortuous legs 24b. A corresponding portion 240 of each leg is disposed within the shaft groove 180. The free end 24d of one of the legs 24b is angularly oflset and subtends the free end 24c of the other leg and serves as a stop to prevent the free ends 24d and 24:: being spread out relative to one another beyond the elastic limit of the wire material. Thus, by reason of this fact, it is assured that the legs 24d and 24s are always in the state of positively gripping the groove 18c.
Disposed on the side of shoulder 18b, opposite from shaft end 18a, is a pair of annular axially spaced grooves 18d, which, when the pump is assembled, are disposed outside the compartment 13. The grooves 18d are adapted to accommodate compressible rings 25 formed of suitable sealing elastomer material.
Spaced axially from grooves 18d in a direction away from shaft end 18a is an enlarged shank portion 182, which is adapted to be encompassed by a sealing spring 32, the latter to be discussed more fully hereinafter. The shank portion 182 terminates in an enlarged countersunk end 181 which forms a shoulder 18g against which one end of spring 32 engages. The countersunk open- 1811 formed in end 18 is adapted to receive a protruding end of motor shaft 35 which is enclosed within housing 20. Both motor shaft 35 and shaft end 181 are provided with key-ways for accommodating a key 36. Impeller shaft 18 may be adjusted axially with respect to motor shaft 35 and held in any desired adjusted position by means of a lock screw 37, threadably mounted in countersunk end 18f. By permitting shaft 18 to be adjusted relative to motor shaft 35, it is possible for the impeller 14 to be properly located within compartment 13 whereby a clearance 13a is provided between impeller 14 and casing section 12b.
The pump 11 also comprises a collar 26 formed of a durable wear-resistant material which is adapted to encompass the annularly grooved portion 18d of the shaft as well as the rings 25. One end 27 of collar 26 is finished flat and is adapted to abut an exposed boss portion 28 of the casing section 12b which surrounds the opening 17. The collar 26 has the center bore 30 thereof of such dimension as to cause the rings 25 to be in a state of compression when the latter are encompassed by the collar. Contacting the exposed back end of the collar, or that end of the collar opposite from end 27 is a retainer washer 31. The center opening of the washer is of such size that it permits the washer to move axially of the shaft only to a point, however, where the washer would come in contact with one of the compressible rings .25. That is to say, the diameter of the opening formed in the retainer washer is considerably leSs than the diameter of the bore 30 formed in collar 26. The retainer washer 31 is engaged at it back side by one end of a coil spring 32, heretofore mentioned, which is adapted to encompass the shaft shank portion 18a. The outer end of the spring 32 rests against shoulder 18g formed on shaft 18. The retainer washer 31 serves a dual purpose, first, it effects substantially uniform distribution of the pressure exerted by the spring on the collar 26 thereby eifecting a more positive contact of the whole end face 27 of the collar with the corresponding face of the boss portion 28 of the casing section 12b. Secondly, the retainer washer 31 prevents the sealing assembly from becoming disassembled when the casing sections 12a and 1217 are removed from shaft 18.
In disassembling the pump 11, the clamping ring 21 is first removed so as to permit casing section 12a to become detached from casing section 12b. The impeller 14 and retaining clip 24 are then accessible so that the clip 24 may be disengaged from groove 18c, and then washer 23 and impeller 14 slipped endwise off the shaft. Casing section 12b is then likewise removed endwise from shaft 18 whereupon spring 32 causes washer 31 and collar 26 to move to the right, as viewed in Fig. 1. Washer .31, however, will move to the right along shaft 18 only until the Washer reaches the left-hand ring 25, which is disposed within a shaft groove 18d. The collar 26, because of friction between its center bore 30 and rings 25, will remain on the shaft, even though casing section 12b has been removed, until it is manually moved endwiseof the shaft a suflicient amount to clear both rings 25, whereupon the collar may be readily cleaned or replaced, if required.
In reassembly of the pump, the casing section 12b is slid over the shaft against the motor cover and the impeller moved toward the motor so as to engage the tapered side of the shoulder 18b. It is preferred that the impeller and inward face of the casing 12b be spaced at distance of about one-sixteenth of an inch. This can be accomplished, as heretofore indicated, by shifting the pump shaft 18 with reference to the motor shaft 35 to provide this spacing. The pump shaft is then locked in place by a set screw 37 or any other suitable means.
.Thus it will be seen that a pump construction and a sealingv assembly therefor have been provided which assembly permits the necessary parts of the pump to be cleaned without the entire sealing assembly being disassembled. Furthermore, the sealing assembly is sturdy in construction, effective in operation, and inexpensive to produce.
While a particular embodiment of this invention is shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made and it is contemplated, therefore, by the appended claim, to cover any such modifications as fall within the true spirit and scope of this invention.
A pump construction designed for rapid assembly and disassembly of parts comprising a separable casing made up of a support frame, a partition section and an impeller housing, each of the casing sections having cooperating peripheral flanges, a peripheral clamping ring coacting with .the flanges to hold them in tight abutting assembled relationship, a sealing gasket interposed between the flanges of. the partition section and impeller housing to produce a fluid tight joint, an impeller shaft protruding through an opening in the partition section and extending into the housing section, the shaft having a shoulder and an annular-groove spaced therefrom near the inboard end, an impeller mounted on the shaft against the shoulder, a safety-pin type of fastener fitted into the groove and holding the impeller in position, and a seal assembly for said shaft opening carried on and movable with the shaft portion exterior of the casing and movable therewith, said shaft portion having a plurality of grooves adjacent the shaft opening, compressible rings in said grooves, a collar unit encompassing the rings, the latter being in a state of compression when enclosed by the collar unit, an adjustable shoulder means mounted on said shaft and spaced from the collar unit, spring means around the shaft and cooperating with the collar unit and adjustable shoulder means to efiect urging of the collar unit into abutting rotatable sealing relation with respect to the exposed adjacent portion of the opening in the partition and a retaining washer around the shaft portion and disposed between the spring means and collar unit to limit movement of the spring in disassembly of the pump, the internal diameter of the washer being smaller than the rings in the uncompressed state to restrict move ment of the washer along the shaft.
References Cited in the file of this patent UNITED STATES PATENTS 883,155 Westinghouse Mar. 24, 1908 2,268,218 Lum Dec. 30, 1941 2,371,250 Maroney Mar. 13, 1945 2,470,419 Voytech May 17, 1949 2,494,887 Lenhart Jan. 17, 1950 2,688,930 Moss Sept. 14, 1954