US2092740A - Rotary pump - Google Patents

Description

ROTARY PUMPl vFiled Dc. 29. 1956 FIGA; Fles Plas FIGB v NVENTOR: ADoLF l ARGEBOER- ATTQRNE/KS Patented Sept. 7, 1937 PATENT OFFICE.

' no'rnnr PUMP 4Adolf Bargeboer, The Hague, Netherlands, as-

signor of a part interest to Machinefabriek- Gebr. Stork & Co. N. V., Hengelo (0), Netherlands, a Dutch manufacturing company Application December 29, 1936, Serial No. 118,043`

In the Netherlands November 16, l1935 9 Claims. (Cl. 23o-79) This invention relates to rotary pumps, more especiallyrotary air pumps of the type, which comprises, in combination with a revolubie bladed rotor, a pump chamber having an outlet port, an inlet port or a plurality of inlet ports arranged laterally of said rotor and extending through less than 180", and a guide or working channel provided radially outside the rotor and open only on the side facing the rotor, the inner wall of the pump chamber having, between-the outlet` port and the inlet port (considered in the directin of rotation), a segmental portion tting the rotor with the least possible clearance so as to form a seal.

In a pump of this known type, the pressure increases in the direction from the inletl or suction port towards tne outlet or delivery port, and the capacity of the pump to produce this pressure is generally attributed to the action of a water ring, which, on the suction side, is expelled from the rotor cells under centrifugal force and, on the delivery side, is forced again to .enter the cells,

thus creating both the partial vacuum required for the suction and the overpressure required for the delivery. I

Actual tests have now revealed the fact that this explanation of the operation of pumps of this type is Vnot correct and that the energy supplied and absorbed by the water during said radial movement is of minor importance and is, `for the greater part, lost-by friction.

The' inventor has found that the operation of the pump is due to a continuous increase of the energy accumulated in the water, owing' to the rotor blades throwing the retarded water, at full circumferential speed, from the cells into the guide or working channel, wherein the water gives off its energy and whence it returns into the cells with a certain amount of retardation.

Reference is had to Fig. 1 of the annexed drawing, in which said additional movement oi the water is indicated by arrows.

Consequently, there is no question of a relatively quiet, revolving water ring. On the ccntrary, a rather violent interaction takes place between the water in the guide channel and that in the various rtor cells. This interaction involves considerable\energy losses, which account for the low eciency and the unsatisfactory pumping action, viz. essential reduction of the capacity with increasing delivery pressure.

The object of my invention ris to'impart the indispensable supply of energy to the water ring in a novel and improved manner, so that the water eddies, which are located pa. tly inside and partly outside the rotor cells, are caused to whirl about tangentially, and notand at least not exclusively-about axially directed axes.v With this object in view, I propose to arrange the outer edges of the rotor blades in non-parallel relation with the rotor axis. Stated in other language, those edges of... the blades, which are located in the circumference of the rotor, are composed of portions ,that are unequally spaced from the axis of rotation.

It goes without saying that between the outlet port and the inlet port, considered in the direction of rotation, the walls of the casing should fit the profile of the blades with the least possible clearance and thus provide for the required sealing between said ports. f

This apparently-insignificant modification of the known construction results in a considerable improvement as regards the eiiiciency and the, pumping action.

In order that my said invention may be more fully understood, reference is had to the drawing, in which:

Fig. 1 isa diagrammatic side view of a bladed rotor of known construction, as referred to hereinbefore,

Fig. 21s an axial sectional elevation of a rotary pump in accordance with my invention,

provided with ball bearings 2, 2 for the shaft 3. 40

Secured to said bracket .by means of bolts 4 is a casing 5, which is provided, in addition to the deliverynozzle 9 and the suction nozzle I0, with a vertical partition 5B isolating said nozzles from one another.

Connected to the casing 5, by bolts II, is the pump chamber proper, 'which chamber is composed of a at disk 6 provided with an loutlet port I3 and an inlet port I4, an annulus I having an enlarged top portion, and a flat cover 8 forming 50 a bearingfor the shaft 3. Keyed upon this shaft for rotation within-said chamber is the bladed rotor I5. s

Between the inlet port I4 and the outlet port I3, the circumferential inner wall of the pump chamber is radially spaced from the substantially radial outer edges of the rotor blades so as to define a circumferential guide channel extending around part of the rotor, but the inner -5 wall of the top portion of the annulus 1, i. e. of the portion extending between the outlet port I3 and the inlet port ,just suiliciently clears the rotor to allow the same to freely revolve.

Each rotor blade is provided with a rectangular radial projection II on its outer end, the

top portion of the annulus 'I having a corresponding circumferential groove, the inner wall of which snugly ts the lateral edgesof said projection.

In the embodiment shown in Fig. 4, each blade has two trapeziform projections.

Fig. 5 shows an embodiment, in which the rotor blades are encircled by two straps or rings I1, i8, each having a plurality ofradial projections I9, 20. It will be understood that these projections may be located either in the radial planes of the blades, or intermediate said planes.

In Fig. 6, the radial edges of the blades are arcuate.

Fig. 7 illustrates a pump in which the action of the radial projections of the blades is imf proved by a special shape of the circumferential inner wall of the pump chamber, i. e. 'of the annulus 1. As shown, this wall in axial section is not bounded by a straight line, but by a curved and broken line, which is more or less the reflected image of the outer blade edge, so as to denne two shallow grooves 2i and 22 in juxtaposition.

In accordance with Fig. 8, the action of the bladed rotor is improved by the fact that the 'circumferential wall of the guide or working channel, which in axial section may be straight, broken or curved, is corrugated (instead of circular) in a section at right angles to the axis.

In the pump illustrated inFigs. 9 and 10, the radial projections-of the blades are made inoperative i'n the regions of the inlet and outlet v,ports by reason that the circumferential wall of the guide or working channel is provided, in said regions; with ridges for sealing the lateral edges of said projections. These ridges may extend through the full circumferential lengths of said ports, or through only a portion thereof.

I t may also be added that part of the guide channel may be located laterally of the rotor,

instead of exclusively radially outside the same.

What I claim is:

.1. In a pump, more especially an air pump.' a

-rotor mounted for rotation about an axis and provided with blades, the outer edges of which are innen-parallel relation with said axis, 'a pump chamber enclosing the bladed rotor, an inlet port provided in the chamber laterally of the rotor and extending through less than half the circumference thereof, an outlet .port provided in the chamber laterally of the rotor and extending through less than half the circumference thereof, an inner wall portion of the casing between the outlet port and the -inlet port formed to seal the rotor. and a working channel portion provided in the chamber disposed radially outside the rotor' between the inlet port -and the outlet port and open only on the side facing the rotor.

2. In a pump as claimed in claim 1, the feature that the outer edges of the blades have broken outlines.

3. In a pump as claimed in claim 1, the feature that the outer edges of the blades are curved.

4. In a pump as claimed in claim l, the feature that the outer edge of each blade is provided with a substantially radial projection cooperating with the guide channel portion and the seal formed by the inner wall portion.

5. In a pump as claimed in claim l. the feature that the blades are encircled by' a ring provided with radial projections.

6. In a pump as claimed in claim 1, the feature that the circumferential wall of the guide channel is corrugated in a section at right angles tol the axis.

'1. AIn a pump as claimed in claim l, the feature that the outer edge of each vblade is provided with a substantially radial projection and that the circumferential wall of the guide channel is provided, in the region of Aa port, with circumferential ridges adapted to seal the lateral edges of said projections.

8. In a pump aceording'to claim 1, the feature that the outer edge of each blade is pro vided with a radial projection ofpredetermined shape adapted to cooperate with the sealof the inner wall portion, and the channel portion has a predetermined form.

9. In a pump according to claim 1, the feature of having the outer edges of the blades carrying a plurality of spaced radial mojections cooper- Annul' nai-ramona.

Images