US 2003350 A
Description (OCR text may contain errors)
June 4, 1935. A. c. DURDIN. an 03,
Filed Oct. 13, 1935 Jlll INVENTOR.
vii/9:15 5 600/11 17,
. l BY 4 ATTORNEY.
Patented June 4, 1935 PUMP Augustus G. Durdin, 3d, Chicago, 111., assignor to Chicago Pump. Company, C
poration or, Illinois hicago, 111., a cor- Aspnaamom 13, 1933, Serial N6. 693,439
This invention relates to pumps, and more particularly to centrifugal or rotary pumps, and it has reference more especially to the impellers or rotors used in pumps of this character.
An object of this invention is to obtainincreased efliciencyand to maintain as simple and inexpensive a construction as is possible. One objection which prevails in pumps of this class is that considerable friction is developed between the liquid and the'circular or end wall of the pump casing, the impellers of the pumps, now on the market, acting to throw the liquid against the end wall while forcing it from the suction inlet to the discharge outlet.
Usually buckets are provided in the two faces of the impeller adjacent or at the periphery of the disc, which buckets force the liquid along, and due to the centrifugal action, the liquid is thrown outward against the end wall of the chamber in which the impeller rotates, causing friction which hinders the flow of the liquid.
In accordance with the present invention, the bottoms of the buckets are so shaped that the water or other liquid is thrown in a lateral direction from the impeller, whereby it does not impinge upon the end wall of the chamber, thereby friction between the flowing liquid and the walls of the chamber. As a result a greater quantity of liquid can be pumped with a pump of given size using the same power.
The invention consists in the several novel featureshereinafter fully set forth and claimed.
The invention is clearly illustrated in the accompanying drawing, in which- Fig. 1 is a side elevation, partly broken away,
' of a pump embodying a simple form of the present invention;
Fig. 2 is a view, partly'in end elevation and partly in central vertical section taken on the line 22 of Fig. 1;
Fig. 3 is a detail fragmental side elevation of the impeller, and
Fig. 4 is a detail fragmental cross section taken on the line 44 of Fig. 3.
Referring to said drawing, the reference character l0 designates a housing, provided with a hollow boss II, in which is contained a bearing bushing l5 for a shaft I5. Desirably packing I3 and a gland l2, with its usual bolts (one of which is shown at [4) are provided for making a tight joint around the shaft.
The casing is. provided with an end plate I! held on the casing by cap screws l8, and the casing is provided with a suction inlet l9 and a discharge outlet 20 separated by a common wall 2| within the casing proper.
An annular flange 22, formed on the inner face of the wall l0 of the casing, and a corresponding flange 23 formed on the inner face of 5 the end plate l1, divide the casing into a single race-way or chamber 24, and two other chambers. 25, 26. The water or other liquid is forced through the single chamber 24 from the suction inlet I9 to the discharge outlet 20.
The impeller 30 has a disc like portion 32, and a hub 21 carried by the shaft l6. Desirably the disc like portion is formed with an annular groove 28 in each side face, and equalizing passages, one of which is shown at '29, are 15 formed in the disc within the grooves 28 to equalize the pressure in the chambers 25, 26. The opposite faces of the disc like'portionfif the impeller are machined smooth and parallel and the peripheral edge is machined smooth.
(The peripheral portion of the impeller extends between the flanges 22, 23 and into the chamber 24, with its periphery spaced considerably away fromthe end wall Ill of the casing so as to leave a free space between the peripheral face and the side faces of the peripheral portion of the disc andthe end and side walls of the chamber 24. v
Adjacent its periphery thedisc is provided in both of its side faces with circumferentially disposed buckets that urge the water or oth er liquid forward in the chamber 24. The bottoms 3| of the buckets are desirably concave or curved,
. being directed inwardly from the sides of the disc and outwardly to the periphery of the disc 35 along'curved lines that approach the edges of the disc. It will be observed from an inspection of Fig. 2 that the arcs which define the bottoms of the pockets, are parts of circles struck from centres located between the side walls 0f 40 the casing and the disc. As a result, lines parallel with the axis of the impeller and-tangent with the outer parts of circles, struck from-the centres of the arcs, are radially within the outer wall. The sides of the buckets comprise webs 4o 1 33, desirably formed of rectangular plates that are let into slots 34 formed in the peripheral portion of the disc and secured therein by weld-- ing, brazing or otherwise permanently securing them in place.
Desirably the buckets may be formed as fol-' lows: Both sides of the peripheral portion of, the disc are machined to form annular grooves or recesses 3|, the bottoms of which are arcuate and intersect the sides and peripheral edge of the disc pled to the pump shaft. Water is drawn through the suction inlet, and forced through the chamber 24 to the discharge outlet. While passing through the chamber 24 the water is repeatedly caught by the buckets of the impeller and is thrown therefrom into the single race-way or chamber 24 taking substantially helical paths at both sides of the impeller, a very minimum amount of the water being thrown against the end wall l0, consequently friction between the flowing water and end wall is practically reduced to a minimum. The arrows in Fig. 2 indicate generally the direction taken by the water entering and leaving the buckets.- As a result the helically moving water drives forward the body of water contained in the outer part of the raceway, because the helically moving water, when leaving the buckets is thrown against the surrounding water when following its path back to the pockets. The-energy imparted to the helically moving water by the impeller, develops pressure in the outer body of water;
It will be apparent that by rig the friction between the flowing water and the end wall, the efliciency of the pump is greatly increased and that a greater quantity of liquid can be pumped with a pump of given size, using the same power.
I claim as new and desire to secure by Letters Patent:
1. In combination, a pump casing havinga suction inlet, a discharge outlet and a single raceway therebetween having side and inner and outer end walls, an impeller disc mounted'to rotate in said casing with its peripheral portion extending into said race-way. and circumferentially disposed buckets in the side faces of the peripheral portion of the impeller disc having concave botliquid in the outer portion of the race-way and is directed back into the pockets by the side and inner end walls.
2. In combination, a pump casing having a suction inlet, a discharge outlet and a single raceway therebetween, having side and inner and outer end walls, an impeller disc mounted to rotate in said casing with its peripheral portion extending into said race-way, and circumferentially disposed buckets in the side faces of the peripheral portion of the impeller disc having concave bottoms, terminating at the side faces and peripheral edge of the impeller disc, the bottoms of said buckets being in the form of arcs of circles struck from centres disposed between the side walls of the race-way and the sides of the impeller disc, whereby liquid is discharged from the outer e'nds'of said pockets in lateral directions against the liquid in the outer portion oi. the race-way, and is directed back into the pockets by the side and inner end walls.
3. In combination, a pump casing having a suction inlet, a discharge outlet and a. single raceway therebetween, having side and inner and outer end walls, an impeller disc mounted to to tate in said casing with its peripheral portion extending into said race-way, the parts of the raceway between the side walls thereof and the impeller disc being narrower than the part located between the outer end wall and the periphery of the impeller disc, and there beingcircumferentially disposed buckets in the side faces of the peripheral portion of the impeller disc, flaring outwardly in a direction from the axis of the impeller towards its periphery, said buckets being formed by annular grooves extending inward from the sides of the impeller disc intersected by cross walls, the cross section of each groove being in the form of an arc of a circle struck from a centre located between the adjacent side wall of the race-way and the side of the impeller disc. I
. AUGUSTUS C. DURDIN III.