US 2684035 A
Description (OCR text may contain errors)
P. G. KEMP FLUID PUMP July 20, 1954 Original Filed Oct. 2, 1947 MUH [NI/EDITOR. 1 /01/4 6. AfM/ Patented July 20, 1954 UNITED STATES FAT ENT OFFICE Original application October 2, 1947, Serial No.
777,443, new Patent No. 2,649,706, dated August 25, 1953.
Divided and this application November 23, 1949, Serial No. 128,963
4 Claims. 1
This invention relates to a pump for liquids of'the type having a rotary impeller and a plurality of vanes on the impeller for moving liquid through the pump.
t is an object of this invention to provide a rotary pump which is relatively'small in size'but which is capable of delivering 'a large volume of liquid at a relatively high pressure.
The pump of this invention is particularly adapted for-use on a washing machineof the type wherein the washing action is obtained by directing streams of water at the clothes at a relatively high velocity and from different angles. A washing machine of this type is disclosed in my co-pending application, Serial No. 777,443, filed October 2, 1947, now Patent No. 2,649,706 issued August 25, 1953, of which this application is a division. In the drawings;
Figure 1 is a vertical sectionthrough thepump.
Figure 2 is a horizontal section taken along lines 2-2 in Figure 1.
In a. washing machine of the type disclosed in the above-mentioned co-pending application, the water which is directed against the clothes as jets is continuously recirculated and the pump of this invention is particularly adapted for this purpose since the pump is small in size and capable of delivering a large volume of water at a relatively high pressure. It will be understood, however, that the use of my pump is not restricted to washing machines and that the pump is adaptable for use in a large variety of different applications where it is desired to pump liquids in large quantities and under relatively high pressure.
Since-the pump is admirably 'suitedfor the operation of a washing machine of the above type, its construction and operation will be described, for the purposes of illustration, in conjunction with a washing machine. Such a Washer is usually provided with an inlet in which leads to the water nozzles (not shown) and a drain pipe 12 which connects with the bottom of the washer tub (not shown). The pump includes a housing 14 having side walls It and it and a circumferential wall 26. Wall i6 is formed with an inlet opening 22 at the center thereof which extends axially into housing. M. At one side of the pump, the peripheral wall is intersected by :an outlet passage 2t. Outlet 24 is arranged to be connected to the inlet it of the washer by a clamp 28. Inlet 22 is connected to the outlet l2 of the washer by a clamping member 28.
Within housing It, there is arranged a rotor which comprises a pair of spaced discs 32 and 34 which fit nicely within the peripheral wall'128 of a housing. Rotor 38 issuppo'rted'by a screw 35 which threads into the endof a driving shaft 38 driven by :a motor 49. Shaft 38 is journalled in a water tight packing gland 32 in the side wall 18 of the housing.
At a point just beyond outlet 24 (assuming clockwise rotation of rotortfi'), there is attached to the circumferential wall '26, a tapered step member M which fits between discs 32 and Stand which gradually'increases in height in a counterclockwise direction as viewed in Figure 1. The high end of step Mi terminates abruptly as at E6 so that the step provides a cam which drops on abruptly at its tail end.
The fluid is moved through the pump from the inlet 22 to the outlet 24- by a plurality of flexible vanes 48 which are pivotally supported between discs 32 and 3'4,as by pins 59. Inlet 22 has an extension 52 which projects axially into housing It and terminates at a'point spaced only slightly from disc 31% of rotor 30. Each vane 18 is backed by a pine-which'limits the pivotal movement of 'thevane and causes the vane to assume the flexed position, shown in Figure l, with the pivoted end 5% of the vane engaging the outer surface of extension .22 and with the free end 53 of the vane wiping against the circumferential wall 2 8 of housing M. Varies 48, it will be noted, divide :the interior of housing M into a plurality of generally radially extending rotating chambers For the best efficiency of the pump, vanes 48 must be flexible enough to ride up cam 44 without consuming too "much power and must be'highly resilientsio as toiinstantaneously spring ibacl; to their normal 'flexedcontour at the mo- :ment they trip over thelhigh end 46 of step M. I have found that vanes formed of treated rubber are ideal for thistpurpose'.
Liquid is admitted into the pump, that is, into chamberstil, through inlet ZZ-by means of a restricted opening 62 which is formedon the side oflextension 52 opposite outlet 2 5. Opening 82 is arranged such that water is admitted to the chambers formed byvanes 48 just after the vanes havedischarged the water through outlet 24 and at'the moment they "trip over the high end bit of step M. Opening 62 preferably extends axially across the full width of vanes ii) and extends circumferentially of extension 52 for a range of about to 150. I have found that with an opening of approximately the pump attains its maximum efiiciency. Openings considerably less than 126 provide too short a period for the entrance of water into chambers 60 and openings in excess of 150 admit water over too wide a range and the water voided at outlet 24 would therefore not be subjected to the desirable effect of the centrifugal force produced by rotor 30. Theoretically the water from inlet 22 should be available to the rotor vanes at the exact moment they trip over the high end of cam 44. In practice I have found that a lag occurs in the action of vanes 48 and that the best performance of the pump is obtained if the restricted opening in inlet extension 52 is advanced slightly in the cycle so that water is actually admitted to a particular chamber just before the free end of the forward vane of each chamber trips over the high end of cam 44.
Assuming that motor 40 drives rotor 30 in a clockwise direction as viewed in Figure 1, each vane 48, after passing outlet 24, rides up the tapered step 44 and then suddenly drops oil? the high end of the step. As vanes 48 flex in traveling up the cam surface of step 44, the chambers between the vanes engaging step 44 are gradually reduced in volume until the forward vane of the chamber reaches the end 46 of step 44. As the vane trips over this end of the step it springs back to its original contour and in so doing produces a sudden enlargement of the chamber and creates a partial vacuum in the chamber behind it. This sudden enlargement of the chamber causes a surge of water to flow through the restricted opening 02. The water flows into each chamber not because of gravity but because a partial vacuum is suddenly created in the chamher just as the mouth of the chamber coincides with opening 52. The water thus admitted to the chamber is rotated by the vanes at a high velocity and is discharged through outlet 24 at a relatively high pressure.
It will thus be seen that I have provided a pump for moving liquids, which is very efficient in proportion to its size. I have found that when used on a washing machine of the type disclosed in my said co-pending application, the pump can be driven by a small horse power motor connected to the ordinary household electrical outlet. It is my opinion that the improved performance of my pump can be attributed to the fact that the water is sucked into the pump not only through the action of the rotating rotor but also because a partial vacuum is created in eachchamber at the moment the mouth of the chamber registers with the restricted inlet opening 62.
What I claim is:
1. In a rotary fluid pump of the type having a generally circular housing and a rotary impellor within said housing, a plurality of flexible and resilient vanes on said impellor arranged to wipe against the inner peripheral surface of said housing and dividing the housing into a plurality of radial chambers, each of said vanes forming the forward wall of one chamber and the rearward wall of the next adjacent chamber, step means extending around a portion of the inner peripheral surface of said housing, said step means tapering in thickness from one end thereof to the other end thereof so that said step means increases in height in the direction of rotation of said impellor, said step means terminating abruptly at the high end thereof, inlet means projecting axially into and through the central portion of said housing and having a circumferential port at one side thereof, said port being arrange to admit fluid in a radially outward direction into said chambers just as each vane forming the forward wall of said chamber wipes over the high end of said step means, and an outlet on the periphery of said housing spaced circumferentially from said port and adjacent to but in advance of the low end of said step means.
2. The combination as set forth in claim 1 wherein said port extends circumferentially of said inlet means in the range of -150.
3. A rotary fluid pump comprising a housing of generally cylindrical shape, a cylindrical conduit projecting into said housing and extending along the axis thereof, a rotary impellor mounted within said housin on an axis concentric with the axis of the housing, a plurality of radially extending vanes supported at their inner ends on said impellor, said vanes being formed of a resilient material and being mounted on said impellor with their outer ends wiping over the inner peripheral surface of said housing and with their supported ends wiping over the outer peripheral surface of said inlet conduit, means forming a step on a portion of the inner peripheral surface of said housing, said step tapering in thickness from one end thereof to the other end thereof so that the step increases in height in the direction of rotation of said impellor, said step terminating abruptly at the high end thereof such that as the vanes wipe up said step the size of the adjacent chambers is progressively decreased and as the vanes wipe past the high end of said step the size of said adjacent chambers is suddenly increased and a sudden partial vacuum is produced therein, said inlet conduit having a circumferential opening therein arranged to communicate with each chamber between the inner supported ends of said vanes substantially at the moment said partial vacuum is produced in said chamber, and outlet means on the periphery of said housing adjacent and in advance of the low end of said step means, said vanes being of sufficient length to wipe against the inner peripheral surface of said housing except at said outlet means.
4. The combination set forth in claim 3 wherein said vanes are pivoted at their inner ends on said impellor, the length of said vanes being substantially greater than the radial distance between the inner peripheral surface of said housing and the outer peripheral surface of said inlet conduit, and means for limiting the pivotal movement of said vanes on said impellor such that they normally assume a flexed position.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date None Peters et al Oct. 31, 1835 2,189,356 Briggs Feb. 6, 194.0 2,332,411 Swanson et a1 Oct. 19, 1943 2,460,421 Kinconnon Feb. 1, 1949 2,466,440 Kiekhaefer Apr. 5, 1949 2,599,600 Arnold June 10, 1952 FOREIGN PATENTS Number Country Date 2,024 reat Britain of 1893 47,930 Norway May 19, 1930 456,679 Great Britain Nov. 13, 1936