US2862452A

US2862452A - Pumps

Info

Publication number: US2862452A
Application number: US504781A
Authority: US
Inventors: Kenneth R Lung
Original assignee: Tait Manufacturing Co
Current assignee: Tait Manufacturing Co
Priority date: 1955-04-29
Filing date: 1955-04-29
Publication date: 1958-12-02
Anticipated expiration: 1975-12-02

Description

Dec. 2, 1958 K. R LUNG PUMPS Filed April 29, 1955 FIG-1 '21 485 2 Sheets-Sheet l INVENTOR.

KENNETH R. LUNG Y @M Ma AT TO RN EYS K. R. LUNG Dec. 2, 1958 PUMPS 2 Sheets-Sheet 2 Filed April 29, 1955 INVENTOR.

KENNETH R, LUNG ATTORNEYS United States Patent PUMPS Kenneth R. Lung, Dayton, Manufacturing Company, of Ohio Ohio, assignor to The Tait Dayton, Ohio, a corporation This invention relates to sump or drain pumps of the type embodying a centrifugal impeller arranged to be driven on a generally vertical axis by a drive motor located above the pump housing.

The invention is applicable both to pumps of the submers ible type wherein the motor is mounted in close relation with the pump housing for submerging in liquid 1n the space to be drained, and also to such pumps of the type wherein the motor is mounted at a substantial distance above the pump housing for protection against submersion. With both such types of installations, the pump impeller and drive shaft for the impeller are subect to relatively severe operating conditions, especially in cellars and the like where the liquid being pumped may on some occasions be dirty and filled with sediment. Such service conditions result in accelerated wear of the impeller such that repair or replacement thereof is likely to be required more often than with other types of pump installations.

Another operating hazard for pumps utilized for the above purposes is misalignment of the drive shaft for the impeller, and this is especially the case with pumps of the remotely mounted motor type which require correspondingly long drive shafts. If the coupling between the shaft and impeller is rigid, it may be damaged by misalignment, and it is also prone to rusting which will complicate its release for servicing or replacement of the impeller. At the same time, if a fixed coupling is used which requires a set screw or like connection such as threading the impeller onto the end of the shaft, misalignment will usually have a tendency to loosen the set screw or other threaded connection and thus perhaps ultimately to release the coupling unintentionally. On the other hand, unless some provision is made for assuring ready disassembly of the drive shaft and impeller, servicing and maintenance will be correspondingly complicated.

It is a primary object of the present invention to provide a pump construction designed to minimize the effects of the operating difiiculties discussed above, and more particularly to provide such a pump wherein the impeller and its drive shaft are of such construction and arrangement that they are quickly and easily assembled and disassembled as required for installation and maintenance while assuring positive driving action in operation.

An additional object of the invention is to provide such a pump construction which will operate eflectively and efiiciently even if misalignment develops between the impeller and its drive shaft, and especially which is so constructed and arranged that the driving construction between the impeller and its drive shaft is substantially unaffected by misalignment therebetween.

Another object of the invention is to provide a pump construction as outlined above wherein the driving con nection between the impeller and its drive shaft is formed by complementary socket and shaft portions of noncircular section and wherein the impeller is free to rest on the bottom wall of the pump housing when the pump "ice is stationary and is caused to rise out of contact with the pump housing by the pressure forces which it develops in operation, thus assuring a positive driving connection at all times which Will tolerate substantial misalignment without appreciable loss of efficiency.

Still another object of the invention is to provide a pump of the above general construction wherein the impeller is constructed and arranged to develop sufiicient upward pressure thrust in operation as to effect substantial balancing of the weight of the drive shaft and such additional parts are carried by the drive shaft.

It is also an object of'the invention to provide a pump construction having the features and advantages obtained above which is equally applicable to sump or drain pumps of the submersible type and also to sump pumps wherein the drive motor is located at a level substantially above that of the pump housing.

Referring to the drawings, which illustrate preferred embodiments of the present invention- Fig. 1 illustrates a sump pump of the submersible type which is constructed in accordance with the invention, the view being generally in vertical section through the motor housing and with the impeller being in section generally on the line 11 of Fig. 2;

Fig. 2 is a view illustrating the details of construction of the impeller of Fig. 1, the view being taken as indicated by the line 22 of Fig. 1;

Fig. 3 is a section on the line 33 of Fig. 1;

Fig. 4 is a perspective view showing a sump pump constructed in accordance with the invention wherein the motor is mounted at a height substantially above that of the pump housing;

Fig. 5 is an enlarged fragmentary section showing portions of the sump pump of Fig. 4; and

Fig. 6 is a fragmentary section on the line 6--.6 of Fig. 5.

Referring to the drawings, which illustrate preferred embodiments of the present invention, Fig. 1 shows a submersible drain pump unit which incorporates a pump housing 10 and a motor housing comprising upper and

lower housing sections

11 and 12 bolted together in sealed relation at 13. The upper housing 11 supports the motor stator 15, which is suspended therein by means of bolts 16, and this housing section also supports the control switch 20 for the motor, which is actuated by a lever arm 21 mounted on the outside of the housing and its associated weight 22 and float 23 on a cord 24, reference being made in this connection to my copending application Serial No. 504,782 filed of even date herewith and assigned to the same assignee as this application now Patent No. 2,748,220 issued May 29, 1956. The electrical supply conduit 25 to the motor enters the housing section 11 through a sealing plug 26.

The drive shaft 30 of the motor supports the rotor 31 and is in turn supported by a pair of

bearings

32 and 33 in the

housing sections

11 and 12 respectively. The lower end of shaft 30 projects through a boss 35 depending from housing section 12 and cooperating with the shaft to mount a rotary seal 36 sealing the interior of the motor housing against access of liquid along the shaft. This seal is supplemented by the bearing 33, which includes sealing disks 37 and 38 carried by the outer race thereof and overlying the ball-receiving space therethrough to minimize pressure leakage in either direction through bearing 33.

' The impeller housing 10 includes a split boss portion 40 at its upper end which fits over the motor housing boss 35 and is secured thereto by a strap-type clamp 41 and clamp bolt 42. The bottom wall of the impeller housing is provided by a removable metal plate 44 which also may conveniently include a downwardly extending flange portion 45 forming the base of the unit,

on the under side of the impeller.

the plate 44 being bolted directly to housing at 46. The interior of housing 10 forms a pumping chamber 50 having inlet passages 51 through the upper portion of the housing between the ribs 52 connecting boss 46 with theylower part of housing 10. A generally tangential-ly arranged outlet passage 53 leads from chamber 50 for connection with a discharge pipe 54. Means such as a perforate cover 55 may be provided for screening solid material from access to the pumping chamber 50 through inlet passages 51.

Within the pumping chamber 51) is the impeller 66, which is shown as cast or molded from a suitable plastic material such as a phenolic resin and which includes a shroud portion 61 forming the bottom of the impeller and a plurality of upwardly extending curved vanes 62. A hub portion 63 on the upper side of the impeller forms a socket 65 of non-circular section to receive the complementary end portion of shaft 30. Thus Fig. 2 shows the socket 65 as including a slotted keyway 66 in an otherwise circular bore to receive a key 67 carried by shaft 30. Such a driving connection, which provides for axial movement of the impeller with respect to the drive shaft, is referred to herein generally as a splined connection, and the upward limit of such sliding movement of the impeller is established by engagement of the end of the shaft with the bottom of socket 65, which preferably is reinforced by one or more suitable thrust washers 68.

With this construction, when the motor is not in operation, the impeller 60 is able to slip down the shaft 30 until it rests on the wall 44, but when the pump is operating, the pressure developed by the vanes 62 will be efiective underneath the impeller to develop an upward pressure lifting the impeller along the shaft to its upper limit position for free rotation above wall 44. This construction has the further advantage that the driving connection between the impeller and the shaft is not disadvantageously affected by relative misalignment therebetween. In addition, removal and replacement of the impeller is very simple, requiring only the removal of the bottom plate 42 from the housing 16 followed by axial removal of the impeller from the shaft and its replacement of a new impeller.

In order to assure proper development of the desired lifting force effective on the impeller, an abutment may be provided between the impeller and wall 44 for supporting the impeller and its shroud spaced above the wall 44 during non-operation of the pump. Such abutment may be conveniently formed as shown by a spherically curved portion 70 substantially centrally located The abutment 76 need not be large, and satisfactory results have been obtained with the abutment curved on a radius of inch and having a total projection of only V inch below the bottom plane of shroud 61 on an impeller having a maximum outer diameter of approximately 4% inches.

In addition to the lifting force on the impeller with respect to shaft 30 developed by the impeller itself in operation, the pressure effective between the impeller and the bottom wall of the impeller housing may also be employed to establish effective balancing of the weight of the shaft as well as that of other parts movable axially with the shaft such as the rotor 31, and thereby to minimize the thrust load on the

bearings

32 and 33. In fact, such lifting force may be in excess of the weight supported by the shaft to such extent as to produce an undue upward thrust load on the bearings, and a special structural configuration for the impeller is accordingly provided by the present invention to reduce the upward force developed thereby to a value properly coordinated with the Weight of the shaft and its associated rotating parts. As shown in Fig. 2, the shroud portion 61 of the impeller is of sharply serrated configuration, with each serration having one curved outer edge '71 substan tially conforming with the outer edge of the vane 62 thereon and a straight opposite edge 72 substantially conforming with a radial line connecting the tip of the vane thereon with the next adjacent vane, thus producing the desired reduction in the total bottom area of the shroud as compared with the area of a circle of essentially the same diameter as the maximum outer diameter of the impeller.

Figs. 46 show a sump pump of the pedestal type constructed in accordance with the present invention and also embodying some of the features disclosed in my copending application Serial No. 320,392, filed November 14, 1952 now Patent No. 2,766,696 issued Oct. 16, 1956, and assigned to the same assignee as this application. The impeller housing 1% is generally of similar construction to the housing 16 and is bolted at 101 to a base plate 162 which also forms the bottom wall of the pumping chamber 105. The inlets 106 of chamber 1165 are covered by a perforate dome-shaped cover 1117, and the outlet 108 corresponds to outlet 46 in Fig. 1. The drive motor 116 is supported above housing by a tubular pedestal 111 which is secured by clamps 112 to boss portions 113 and 114 of housing 100 and motor 116 respectively, and the motor switch is indicated as operated by a float rod 16 having a float 117 at its lower end.

The impeller 120 in Fig. 4 is of essentially the same general construction as impeller 60 and includes a similar shroud portion 121, vanes 122, spherical abutment 123 and hub 124 forming a socket 125. The impeller 120 is connected with the motor shaft 126 by a connect ing shaft 13@ supported near its lower end by a bearing 131 which is shown as of porous metal force-fitted within the base portion 113 of housing 100. The splined connection between impeller 120 and shaft 130 is provided by a D-shaped end portion 132 of shaft 130 which fits within the complementary non-circular socket to provide the desired axially movable but angularly fixed driving connection. It will be apparent that this same type of splined connection is equally applicable to the pump of Figs. 1 and 2, and vice versa.

In order to provide for maximum ease of assembly and disassembly of the pump of Figs. 3-5, a similar splined connection is shown between the upper end of shaft and the motor shaft 126. A sleeve 135 is pinned or otherwise secured at 136 to the lower end of shaft 126 and depends therefrom. The upper end of shaft 130 is shown as having a D-shaped portion 137 which may be identical with its portion 132, and it fits within the complementary shaped portion 138 of sleeve 135. Thus the advantages of ready assembly and disassembly are available at both ends of shaft 136, although it will of course be apparent that a more permanent connection may be employed at the upper end of shaft 131) if desired.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

What is claimed is:

1. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means forming a splined driving connection between said impeller and said shaft providing for axial movement of said impeller along said shaft, cooperating means on said shaft and said impeller fixing the upper limit position of said impeller on said shaft, said impeller including a shroud forming the bottom thereof and a plurality of vanes extending upwardly from said shroud, means normally supporting said impeller with said shroud spaced above said ward pressure force between said impeller and said wall during operation of the pump causing initial lifting of said impeller on said shaft to said upper limit position followed by a lifting action on said shaft and any additional parts of said drive means supported on said shaft, and the total bottom area of said shroud being correlated with the weight of said shaft and said additional parts of said drive means supported thereon to provide an upward force effecting substantial balancing of said weight during operation of the pump with said impeller in said upper limit position.

2. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means forming a driving connection between said impeller and said shaft constructed to fix the upper limit position of said impeller on said shaft, said impeller including a shroud forming the bottom thereof and a plurality of curved vanes extending upwardly from said shroud, means normally supporting said impeller with said shroud spaced above said bottom wall to provide for the development of an upward pressure force between said impeller and said wall during operation of the pump with resulting lifting of said impeller together with said shaft and any additional parts of said drive means supported on said shaft, and said shroud being of serrated configuration along the outer portion thereof with each serration having one edge substantially conforming with the outer edge of the adjacent said vane and the other edge substantially conforming with a radial line connecting the tip of said adjacent vane with the next said vane to reduce the total bottom area of said shroud and said upward force developed thereby in correlated relation with the weight of said shaft and said additional parts of said drive means supported thereon to effect substantial balancing of said weight during operation of the pump.

3. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means forming a splined driving connection between said impeller and said shaft providing for axial movement of said impeller along said shaft, cooperating means on said shaft and said impeller fixing an upper limit position of said impeller on said shaft, the outer tips of said vanes defining a circle of predetermined area, and said shroud lying substantially entirely within said circle and having a serrated periphery providing a total bottom area therefor substantially less than the area of said circle to effect a correspondingly reduced pressure force between said shroud and the bottom wall of said pumping chamber during operation of said pump.

4. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means forming a splined driving connection between said impeller and said shaft providing for axial movement of said impeller along said shaft, means fixing an upper limit position of said impeller on said shaft wherein said impeller is spaced above said bottom wall, said impeller including a shroud forming the bottom thereof and a plurality of curved vanes extending upwardly from said shroud, means forming an abutment between said impeller and said bottom wall for supporting said impeller with said shroud spaced above said bottom wall during non-operation of the pump to provide for the development of an upward pressure force between said impeller and said wall during operation of the pump with resulting lifting of said impeller along said shaft to said upper limit position for free rotation above said wall, and said shroud being of serrated configuration along the outer portion thereof with each serration having one curved edge substantially conforming with the outer edge of the said vane supported, thereon and the other edge substantially conforming with a radial line connecting the tip of said vane with the next adjacent said vane to effect corresponding reduction in the total bottom area of said shroud and in the total said upward pressure force.

5. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means forming a driving connection between said impeller and said shaft fixing an upper limit position of said impeller on said shaft wherein said impeller is spaced above said bottom wall to provide for the development of an upward pressure force between said impeller and said wall during operation of the pump with resulting lifting of said impeller along said shaft to said upper limit position for free rotation above said wall, said impeller including a shroud forming the bottom thereof and a plurality of curved vanes extending upwardly from said shroud, and said shroud being of serrated configuration along the outer portion thereof with each serration having one curved edge substantially conforming with the outer edge of the said vane supported thereon and the other edge substantially conforming with a radial line connecting the tip of said vane with the next adjacent said vane to eifect corresponding reduction in the total bottom area of said shroud and in the total said upward pressure force.

6. In a pump of the character described including an impeller housing defining a pumping chamber having a bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means on the upper face of said impeller forming a socket of non-circular cross-section, said shaft having a non-circular lower end complementary to said socket and proportioned for free driving fit therein forming a driving connection between said impeller and said shaft to provide for upward sliding movement of said impeller on said shaft, the bottom of said socket cooperating with said shaft to fix an upper limit position of said impeller wherein said impeller is spaced above said bottom wall to provide for the development of an upward pressure force between said impeller and said wall during operation of the pump with resulting lifting of said impeller along said shaft to said upper limit position for free rotation above said wall, said impeller including a shroud forming the bottom thereof and a plurality of vanes extending upwardly from said shroud, the outer tips of said vanes defining a circle of predetermined area, and said shroud lying substantially entirely within said circle and having a serrated periphery providing a total bottom area therefor substantially less than the area of said circle to effect a correspondingly reduced pressure force' between said shroud and the bottom wall of said pumping chamber during operation of said pump.

7. In a pump of the character described including an impeller housing defining a pumping chamber having a flat bottom wall, the combination of drive means including a drive shaft extending generally vertically into said housing from above, an impeller in said housing, means on the upper face of said impeller forming a socket of non-circular cross-section, said shaft having a non-circular lower end complementary to said socket and proportioned for free driving fit therein forming a driving connection between said impeller and said shaft to provide for upward sliding movement of said impeller on said shaft, the bottom of said socket cooperating with said shaft to fix an upper limit position of said impeller wherein said impeller is spaced above said bottom wall to provide for the development of an upward pressure force between said impeller and said wall during operation of 7 the pump with resulting lifting of said impeller along said shaft to said upper limit position for free rotation above said wall, said impeller including a shroud forming the bottom thereof and a plurality of vanes extending upwardly from said shroud, the outer tips of said vanes defining a circle of predetermined area, said shroud having a serrated periphery providing a total bottom area therefor substantially less than said circle to effect a correspondingly reduced said upward pressure force, and an abutment on the bottom face of said impeller substantially in line with said socket to maintain the major portion of said bottom face spaced above said bottom wall during non-operation of said pump to assure development of said upward pressure force upon operation of said pump.

References Cited in the file of this patent UNITED STATES PATENTS Jackson Jan. 29, Waters et a1. Aug. 10, Cook et al. Nov. 17, Yoder Oct. 18, Pollak Oct. 10, Brady Feb. 20, Howser Jan. 20, Edwards Nov. 24,

FOREIGN PATENTS Great Britain Apr. 4,

murnn FJTATES PATENT OFFICE CERTIFICATE 0F QORRECTION Patent No, 2,862,452 December 2, 1958 Kenneth R, Lung It is hereby certified that error appears in the -printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 43, for "of a new" read m by a new column 4, line 2A for "rod 16" read rod 116 column 8, line 9, list of references cited, under the heading "UNITED STATES PATENTS" for "2,542,986 Brady Feb, 20, 1951 read mm 2,542,896 Brady Feb 20, 1951 Signed and sealed this 14th day of April 1959.

"SEAL? ttest:

KARL AXLINE ROBERT C. WATSON Attesting Officer Commissioner of Patents UNITEB STATES PATENT OFFICE CERTIFICATE CF CORRECTION Patent No, 2,862,452 December 2, 1958 Kenneth R, Lung It is hex-e121; certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 43, for "of a new read we by a new column 4, line 24, for "rod 16" read rod 116 column 8, line 9, list of references cited, under the heading "UNITED STATES PATENTS" for "2,542,986 Brady mmne Feb, 20, 1951 read .... 2,542,896 Brady Feb, 20, 1951 Signed and sealed this 14th day of April 1959o gem) ttest:

ROBERT c. WATSON KARL H, AXLINE Commissioner of Patents Attesting Officer