US2692559A - Centrifugal pump - Google Patents

Description

2671954 J. P. ROGERS 2,692,559

CENTRIFUGALPUMP Filed June 25, 1953 INVENTDJ? JuHN P Rum-312s AT TDHNEY ?atented Get. 26, 1954 CENTRIFUGAL PUMP John P. Rogers, Liverpool, N. Y., assignor to Easy Washing Machine Corporation, Syracuse, N. Y., a corporation of Delaware Application June 25, 1953, Serial No. 364,018

1 Claim.

This invention relates to centrifugal pumps, for washing machines, and more particularly to the provision for life-long lubrication thereof.

In centrifugal pumps employed in washing machines, it is usual to drive the pump continuously whenever the main drive motor is operative, so that the pump is always in readiness to remove any wash water at the instant of any outflow through the drain of the wash tub. Thus, the pump is alternately subjected to liquid load or rotates dry. Such wash water is laden with soap or synthetic detergents which have the property of removing oil or lubricant with which it may come into contact. It has accordingly been considered desirable to provide means for lubricating the pump shaft bearings from time to time as by a grease cup to make certain that adequate lubricant is always present. Such pumps generally comprise an impeller having a plurality of vanes mounted upon a circular plate, and the impeller, when subject to liquid pumping operation, generally produces an end thrust on the shaft not present in the absence of liquid, causing limited axial movement of the shaft, tending to wipe traces of lubricant into exposure with the detergent-laden water. Thus, lubricant is gradually consumed by the detergent.

It is an object of the present invention to provide a centrifugal pump of the type described,

wherein axial thrust along the shaft is substantially eliminated. It is a further object of the invention to provide life-long lubrication for the impeller shaft bearings, such lubrication being derived from a wick-filled reservoir, the lubricant being retained by elimination of end play due to impeller thrust.

The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claim.

In the drawings, wherein like reference characters indicate like parts:

Figure 1 is an axial sectional view taken through the pump;

Figure 2 is a transverse sectional view taken substantially on the line 22 of Figure l; and Figure 3 is a transverse sectional View taken substantially on the line 33 of Figure 1.

In the drawings, there is shown a pump casing composed of a shallow cup-like shell Ill and cover plate l2, forming an impeller chamber. The shell I0 is provided with a circular integral rim l4 which is extended in the lower region as at [6 to provide an outlet chamber for a connection to an outlet I8. The plate 12 has an inlet duct or port leading to the pump chamher and substantially coaxial with the impeller therein, and an outlet duct or port [8 connecting with the extended region formed as at It. The casing member ID has a back wall 22 having an integral bearing boss 24. Such bearing boss has a bore 26 in which are positioned spaced porous sleeve bearings 23 and 30. Journaled in the bearing sleeves 28 and 30 is an impeller shaft 32 having mounted on its forward end an impeller 34. The outer end is provided with a drive pulley 36 secured in place on the shaft by a set screw 38.

The impeller 34 comprises a back circular plate 40 having integral radial vanes 42. Spaced from the plate and secured to the outer edges 44 of the vanes 42 is an annular plate member 46 secured to the vanes 44 as by welds 48. The boss 24 is enlarged on the upper side and provided with a large chamber 50 having ports 52 and 54 leading downwardly to the bearing bore 26 and the bearing sleeves 2B and 30. The chamber 50 and the ports 52 and 54 are filled with oil-soaked wicking 55, and the chamber is provided with a cover plate 56.

The bore 26 at the pump chamber end is provided with an enlarged diameter recess 58 in which is positioned an annular packing 60. Suitable thrust washers 62 behind the impeller end 64 between the sleeve 28 and the pulley 36, hold the shaft against and play. It will be seen that the plate 46 during centrifugal pumping will be subjected to pressure of the liquid being centrifugally thrown outward by the vanes 42, and will therefore tend to neutralize the pressure of such liquid upon the disk 40 of the impeller.

The area of the disk 46 will be so chosen in relation to the diameter of the impeller plate 49 as to substantially and effectually neutralize any effect that the pressure of the liquid being pumped might have in creating end thrust of the impeller. Thus, any tendency of the impeller or shaft to move axially or to cause wear upon the spacing washers 62 and 64 will be substantially eliminated, since there will be no impeller thrust when the pump is operating idly and without liquid, and there will be no end impeller thrust when the pump is subjected to liquid being centrifugally expelled from the pump chamber through the pump outlet l8. With the elimina- 3 tion of such end play and wear on the thrust washers 62 and 64, the oil contained in the wicking 55 will serve to maintain the bearing sleeves 30 and 2B saturated during the life of the pump, and end play tending to remove such lubricant will be eliminated.

While a single embodiment of the invention has been illustrated and described, it is to be understood that the invention is not limited thereto. As various changes in the construction and arrangement may be made without departing from the spirit of the invention, as will be apparent to those skilled in the art, reference will be had to the appended claim for a definition of the limits of the invention.

What is claimed is:

A horizontal axis centrifugal pump for washing machines and the like comprising, in combination, an integral casing member having a shallow cup-like impeller chamber, said chamber comprising a relatively flat back wall, a shallow marginal rim, and an extended bearing boss projecting centrally from said back Wall in an opposite direction from said rim, said rim and wall defining a chamber region to receive a circular impeller, and being extended in a lower direction to provide an outlet chamber region peripherally disposed with respect to said impeller region, said boss having an axial bore normal to said back wall and spaced inner and outer porous bearing bushings at opposite ends, a cavity formed in the outer upper wall of said boss, a port connecting said cavity with each of said bushings, oil retaining wicking substantially filling said cavity and ports, an impeller having a shaft, said shaft extending through said pushings and being journaled therein, said impeller having a circular disk wall located immediately adjacent said impeller chamber wall, and a plurality of radial and axially extending vanes of the forward side of said disk wall, an annular thrust plate secured to the outer edges of said vanes and spaced from the circular wall by the axial length of said vanes, said annular plate having an outer diameter substantially that of said circular disk wall, and an inner diameter defining a coaxial inlet port, a relatively fiat cover plate secured to the rim of said impeller chamber having a coaxial inlet port substantially aligned with the annular plate inlet port and an outlet port communicating with the outlet chamber region, the spacing between said cover plate and chamber back wall being suificient to receive said impeller and said annular plate with running clearance, an annular seal mounted in said hub and between the inner bearing sleeve and said back wall, and engaging said shaft, and means for preventing end play of the shaft with respect to the bearing sleeves.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,668,183 Albrecht May 1, 1928 2,078,783 Welch Apr. 2'7, 1937 2,669,932 Ranscher Feb. 23, 1954

Images