US2982223A - Fluid pumps - Google Patents

Description

0 E. ROSAEN May 2, 1961 FLUID PUMPS Filed Feb. 10, 1958 INVENTOR.

OSCAR E.RO AEN ATTORNEYS United States Patent O 2,982,223 FLUID PUMPS Oscar E. Rosaen, Grosse Pointe Farms, Mich. (51 Roslyn Road, Grosse Pointe 36, Mich.)

Filed Feb. 10, 1958, Ser. No. 714,250

4 Claims. Cl. 103-136) of vanes radially slidable in the perimeter of a suitable rotor.

In fluid pumps of the vane type the circular rotor is mounted within a' housing having two diametrically opposite discharge chambers with corresponding diametrically opposite inlets, and because of such construction, a large number of vanes are required. This is due to the necessityof sealing between the high pressure zones and the low pressures zones.

As a result of the use of a large number of vanes, one of the points at which breakage occurs is in the rotor at the bottom of the segments between the vane slots. The greater the number of vanes and vane slots, the shorterv the distance between the bottoms of the slots.

One of the objects of the present invention is to obviate this difiicuty and greatlystrengthen the rotor without lessening the efficiency of the pump.

Another object is to' provide a simple means for balancing some of the pressure exerted between the end-s of the vanes and the pump ring. 7

Another. object is to provide vane pump construction in which a thicker gauge and therefore stronger material may be used to make the vanes.

Still other objects will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which Fig. 1 is a central longitudinal vertical section of the pump.

Fig. 2 is a section on line 2-2 of Fig. 1.

Fig. 3 is an enlargement of a portion of Fig. 2.

In the drawings, the pump is indicated as comprising a housing of two parts and 10A of which the part 10 comprises an end wall having an opening through which enters the drive shaft 11. Shaft 11 is mounted in a suitable bearing 11A held in place by a snap ring 11B and sealed by means of the ring- -11C pressed against the inner race of the bearing by a spring 11D, the ring itself being provided with a perimetral gasket 11E.

The inner end of the passage is reduced in size as shown, providing an abutment for the spring 11D. Coaxial with the shaft 11 and passage, the housing part 10 .is provided with a cylindrical portion sufficiently large to enclose the working parts of the pump which are held in place by the disc-like cap portion 10A of the hous- Formed in the housing part 10 are also the fluid inlet 12 and outlet13, the latter having leading to it two branch passages 13A formed in the wall of housing part 10 and opening to the outlets 14 of the pump proper.

The pump itself consists of a rotor 15 keyed or splined on to shaft 11 between two cheek plates being of the same outside diameter, so as to fit within the cylindrical portion of housing part 10. The cheek plates 16 are substantially identical and each comprises a disc having a central opening through which extends the shaft 11, suitable plain bearings 16A being provided.

The cheek plates 16 are also provided at diametrically opposite locations in their inner faces, with inlet slots 16B open to the outer periphery and sufiiciently deep to open within the pump ring 17. Adjacent the slots 168 the discs are also provided with passages 16C leading from the perimeter to a location opposite the vane slots (to be described) in the rotor and opening thereto. Also, near their peripheries, the plates are provided with passages 13B forming continuations of the passages 13A.

The pump ring 17 as stated above, has a circular outer perimeter but has its inner perimeter divided into four arcuate zones, two of which are arcs having a shorter radius than the other two and only slightly greater than the radius of the rotor, and those of like radius being diametrically opposite each other; The several zones are connected by ramp or inclined sections, all as shown best in Fig. 2. Those zones of the larger radius are the pumping zones and'those ot' the shorter radius are the fsealing zones.

Also, diametrically opposite each other and adjacent one end of a zone of the larger radius, the ring is provided with recesses 14 open to the inside of the ring and to the branch passages 13A of the outlet or discharge 13.

The rotor 15 consists of a disc keyed or splined to shaft 11 and has in its periphery a plurality of radially arranged slots 20 and 21 extending through the disc in an axial direction. The slots 20 are considerably deeper and wider peripherally than the slots 21 and in them are slidably mounted the pumping vanes 22, these bevelled and each provided with a passage 22A extending from the bevel face through to the bottom of the vane and opening to the bottom of the vane slot 20 beneath the vane.

The beveling of the ends of the vanes 22 and 23 reduces the area of contact between the vane and the pump ring 17 to an area which is much less than the crosssectional area of the vane; that is, the bottom face of the vane, therefore, when fluid under the pressure developed in pumping, passes down into the slot under the vane and exerts this pressure to force the vane out against the pump ring, the same fluid pressure is exerted on the bevel face at the outer end of the vane and balances a large part of the pressure in the slot. The balancing pressure is regulated by the location and size of the contact area of the vane. The actual pressure is the difference between that acting on the bottom of the vane and that acting on the projected area of the bevel.

Inthe slots 21, which alternate with the slots 20 and are much shallower and narrower peripherally than the latter, are slidably mounted small vanes 23 which are also bevelled and provided with a groove or grooves 23A extending from the bevel face to the bottom of the slot 21. These vanes 23 are held in the slots by a rib 21A for-med along one edge of the slot, the bevelling of the vane and rib being so related and arranged that the vanes 23 are permitted to move radially outward a sufiicient distance to contact the ring 17 at the zones of shorter radius, but only at such zones.

It will be noted that with the rotor turning in the direction indicated, the passage 22A opens to the forward side of the vane 22 and the grooves 23A in vanes 23 open to the rearward side of the vane, the vanes 22 having their leading edges bevelled while the vanes 23 have their trailing edges bevelled, as indicated in Figs. 2 and 3.

In the operation of the pump, fluid is drawn in through the inlet 12 and through the continuations 12A flows to the passages 16B and 16C leading respectively to the intravane spaces between rotor and ring and to the slots 20 under the vanes 22, and since the pressure ahead of vanes 22 is greater than that behind, the vanes will be forced outwardly against the ring 17, carrying ahead of them the fluid until the chambers 14 permit it. to be discharged.

The vanes 23 as they travel from the inlet 16Bto outlet M are idle. However, as soon as they reach the zone of smaller radius they are forced outwardly to contact the ring 17 by reason of the fact that the pressure behind them is greater than that in front, and-they act as an effective seal during their passage through this zone.

Thus by using the short (radially sealing) vanes 23, it becomes possible to use fewer deep vanes and slots and thereby provide a much stronger rotor with stronger pumping vanes than has heretofore been thought possible and still maintain the capacity and efliciency.

I claim:

1. In a fluid pump of the vane type, an inlet and an outlet therefor, a disc-like rotor provided with radially arranged slots in its periphery, pumping vanes slidably mounted in certain of saidslots, a pump ring surrounding said rotor and contacting the end of said'vanes, said ring being provided on its inner periphery with arcuate portions constituting pumping zones, other arcuate portions in said inner periphery relatively close to said rotor and alternating with the first arcuate portions to constitute sealing zones, sealing vanes slidably carried in other of said slots in the periphery of said rotor between the first mentioned vanes and contacting said ring and means carried by said rotor limiting the outward movement of said sealing vanes so that they contact said ring only in said sealing zones, passage means connecting said inlet to the intravane spaces between said pumping vanes, other passage means leading to the slots beneath all of said vanes to permit said vanes to be urged radially outwardly of their slots by fluid pressure alone, said vanes being provided with outer and inner end surfaces subjected to pumping fluidpressures for balancing the maior portion of the fluid pressure tending to urge the vanes outwardly thereby reducing excessive wear between the vane ends and the inner periphery of said pump ring.

2. The subject matter of claim 1 wherein said fluid pressure balancing means associated with said vanes and slots comprises bevelled outer end surfaces for all of said vanes and passage means in said vanes connecting the bevelled outer end surfaces with the vane slots beneath the vanes.

3; The subject matter of claim 2 wherein said bevelled outer end surfaces of all of said vanes are bevelled from the high pressure side of each vane so as to reduce the area of contact of each vane with said pump ring and afford an end surface area subjected to pumping pressure.

4. A rotor for a fluid pump of the vane type comprising a disc of substantial thickness having in its outer periphery evenly spaced radially arranged slots, pumping vanes freely slidable in certain of said slots, said vanes having their outer edges bevelled from the face which is forward when in operation, sealing vanes in slots intermediate the first mentioned vanes and slots and limited in their slidable movement therein, said sealing vanes having their outer edges bevelled from that face which is rearward when in operation whereby a major portion of the outer end surface of each vane is open to fluid pressure on the high pressure side of each vane, and passage means associated with said vanes for conducting fluid from the bevelled surfaces to the bottoms of the slots under all of the vanes.

References Cited in the file of this patent UNITED STATES PATENTS 600,723 Johnson Mar. 15, 1898 611,700 Miner Oct. 4, 1898 1,350,775 Brauer Aug. 24, 1920 1,618,692 Tompkins Feb. 22, 1927 1,805,063 Wrona May 12, 1931 2,545,238 MacMillan et al Mar. 13, 1951 2,655,110 Sanborn Oct. 13, 1953 2,731,919 Prendergast Jan. 24, 1956 2,752,893 Oleskow July 3, 1956 2,812,748 Simonian Nov. 12, 1957 2,829,603 Clark Apr. 8, 1958 FOREIGN PATENTS 70,322 Switzerland Nov. 1, 1915 150,316 Great Britain Nov. 21, 1921 299,824 Germany Aug. 10, 1917 653,003 France Oct. 30, 1928

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