US2016831A - Fluid pump - Google Patents

Description

Oct. 8, 1935. c. H. HAVILL 2,016,831

FLUID PUMP Filed Oct. 30,1930 2 Shets-Sheet 2 INVENTOR ATTORNEY livery Patented i935 U ITED STATES PATENT oFFlcs Quinn: 1 I I n.

to 'Ecliple Aviation N. 1., a corporation New October 8., 193., Serial N0. 492,298

' 4 Claims. (01. sac-11s) This invention relates to fluid pumps and compressors, and more particularly to pumps capable of use as superchargersfor delivering'quantities of fluid under pressure, as for example, the deof compressed air-to an en ine.

One of the objects of the present invention is to provide novel means for delivering large quantities of fluid at relatively high pressures.

Another object is to provide a novel unitary device of light weight and small bulk, which, when applied to an internal combustion engine, is adapted to perform the combined functions of a diffuser and a supercharger with a high degree of eiiiciency.

A further object is to provide a novel type of supercharger applicable to internal combustion engines and which not only deliversthe motive fluid to the engine at high pressures andthus increases the amount of fuel supplied to and the power delivered by the engine at any particular throttle opening, but also thoroughly atomizes and mixes the fluid received from the carburetor before delivering it to the intake manifold.

A still further object is to provide in a device of the foregoing character, a novel form of multiserves as a velocity imparting and pressure increasing means.

Another object isto provide a multi-stage supercharger one of the stages of which comprises a plurality of component members in tandem relation along the path of movement of the fluid and another of which comprises a mem- -ber disposed adjacent the point of exit of the' fluid from the precedingstage of the supercharger.

Still another object is to provide in a device :of the character described, a combination of impellers at least one of which is of the screwtype and at least one other of which is of the centrifugal type. a A stilli'urther object is to provide a supercharger constituted by a novel arrangement of parts adapted tocombine in a single unit the functions of a velocity imparting propeller, a screw type compressor and a fluid mixing device.

These and other objects will appear more fully in the detailed description of the invention which follows. Although four embodiments of-the present invention are illustrated in the accompanying drawings it isto be expressly understood that these drawings are for the purpose of illustration only, and are not to be construed as denning the scope of the invention, reference be- I Iof type,andwhich are supported and retainedwithin 'FigJisaviewtakenonlinei-lofFigJ;

Fig. 3 is a transverse sectional view along line 3-4 of Fig. 2; v

Fig. 4 is a side elevation of another embodiment the invention;

Fig. 5 isasectionalview takenonline H of Fi 4; a

Fig. 6 shows a-further embodiment of the invention, and Fig. 'I shows another embodiment.

Referring now to the drawings, wherein like reference characters indicate like parts through- 1 out the several views, and more particularly to Figs. 1 to 3, the embodiment of the present invention illustrated therein comprises a multistage supercharger located between the carburetor and the intake manifold of an internal! combustion engine, and having a novel form of impeller which combines in a unitary structure the functions of a multi-bladed propeller and a helical or screw type compressor. As shown, a confining casing 3 of suitable size and form is-i located between the carburetor, which is dial-gr tically'illustrated at l, and the intake manifold i of an internal combustion engine, and forms a passageway through which a motive fluid or mixtm'e forthe engineis supplied from i the carburetor, and in which said fluid is thoroughly mixed and given an increase in pressure and velocity before being supplied to the cylinders ofthe engine. j

Suitably housed and supported within casing 3 is the rotatable assembly of the supercharger including a pair of impellers in sequence relation, the mounting means, for which, in the form shown, comprises a shaft i rotatably supportedin any suitable manner, as, at one end, by a ball bearing I mounted and retained with a housing I, projecting from and removably secured to casing 3, and at the other end, by a pair of bearings In and 8b which may be of either the ball or roller a cylindrical boss 9 projecting centrally from web III of the intake manifold 5. Both bearing housing I and boss 9 are open at their outer ends in order to facilitate assembly of the supercharger,

and housing 8 is provided with-a cover plate ll, secured thereto as by screws l2, for the purposes -of preventing leakage of the mixture out of, or of- -air into, the supercharger casing. 1

Shaft i may be rotated in any suitable manner eitherbyah'ainofgearingdrivenbysome rotat-,

lected so as to give the desired rate of rotation to the shaft for supercharsins, or by'a separate source of power such as a small electric motor. In the form shown, a portion of shaft {between bearings 8a and lb is provided with a set of teeth .which constitute a pinion l3, said .pinion being driven by a gear ll, a portion of the periphery of which extends through an opening II in boss I to engage pinion I3. Gear l4 preferably constitutes an element of a gear train which is actuated by a rotating member of the engine.

The first impeller or velocity producing element nally'splin'ed so as to engage a correspondingly externally splined portion of shaft 3 when the propellers are assembled thereon.

Although the plan form of the blades shown in Fig. 2 uses substantially parallel leading and trailing edges, it should be understood that the invention is not limited to such a form but that any desired plan form may be utilized. In general, in accordance with conventional aircraft propeller practice, the blades may have their greatest width at a point approximately sixtenths of the distance from the hub to the tip in order to move large quantities of air or other fluid at relatively low rotative speeds,

Each propeller is designed to meet theconditions of fluid speed, revolutions per minute, and horse power required, much in the same manner as aeroplane propellers are designed with the result that the propellers II are in themselves highly emcient in moving large masses of air or other fluid and imparting a high velocity thereto.

Preferably in designing the propellers, the pitch of each blade is so selected as to fit the fluid flow with regard to velocity distribution using an efficient angle of attack for the aerofoil section used, an example thereof being shown in Fig. 3. In general, the pitch of the blades of each successive propeller slightly increases from the inlet to the discharge end of the impeller, if more than one propeller is used. In addition, each blade may have a diiIerent pitch at the tip relative to that near the hub in order that the velocity of the air or other fluid, as it passes each succeeding propeller, may be increased more near the tipsof the blades than it is at the hubs in accordance with the laws of continuity of flow whereby the same mass of fluid must be caused to pass each section of the blade. The air or other fluid entrapped near the centre of the blades with its reduced velocity is caused to move by the pitch of the helix formed by the staggered blades. It

. is thus possible with an impeller casing of uniform or increasing diameter from inlet to discharge .to give each particle of air or other fluid a uniform acceleration and increase in velocity 'throughthe casing.

fold of the engine will he possessed of maximum combustion qualities, will now be described.

At the discharge end of the impeller assembly the diffusing chamber 20 at a considerably accel- 7 Mil 0,881 j ing .part of the engine, the gear ratios being se in there is provided, keyed to'theshaft so as to be rotatable therewith, 'a'second impeller 23 of the centrifugal type having a pluralityof blades 21 of suitable shapeand structure, and located preferably directly adjacent thepropeller II or the termination of the series of propellers. In the design of blades 21 the shape and relative disposition is such that the fluid stream on striking the blades will be moved radially outward into erated velocity and at a pressure greater than that attained during passage through the first impeller element l6.

Suitable means are provided for maintaining the members of the rotatable assembly of the supercharger in their proper relative positions upon shaft 3 andwithin the casing, said means comprising in the present embodiment a pair of spacing sleeves 24, which, together with the inner race of|ball bearing 8a, maintain impeller 23 in its properly spaced relation with respect to web 13, and another spacing sleeve 25, which together with the inner race of ball bearing 1 and the lock nut 26 threaded on the outer end of shaft 3, maintain propellers ll in contact with one another and with the impeller 23.

0n operation, the motive fluid to be supplied to the engine, such as a mixture of air and a hydrocarbon fluid, enters casing 3 through inlet 22 from carburetor I, being drawn in at a high 30 rate ofspeed due to the suction created in inlet 22 by the rapidly rotating propellers l1 driven by shaft 6 through gear I4 and pinion l3. Since each propeller I1 is aerodynamically designed to be an efficient means of moving a fluid, the incoming mixture will be given a large axial velocity, depending upon the .pltch of the blades and the speed of rotation of shaft 6. By assembling propellers in juxtaposition and by staggering the blades an approximate helix is formed. 49

Since a helix rotating in a surrounding shell operates as a fluid transmitting device, it is evident'that by making the pitch 'of the helix less than that of the propeller blades, and bearing a definite relation thereto for the best eiilciency under any given set of conditions and by mounting the propellers closely adjacent one another, a portion-of the velocity imparted to the mixture by the individual propellers is converted into pressure due to the difference in pitch between the blades of said propellers and that of the helix, with the consequence that the mixture'is .delivered against impeller 23 with not only increased velocity but 7 also at considerable increase in pressure. Further increases in velocity and pressure occur as the gases are drawn past the impeller 23, by virtue of the construction of the blades 21 and chambers 20 and 26 as above explained.

The gases, in passing through impellers l3 and 21 have also been thoroughly mixed so that a uniform mixture of air and fuel is delivered to the intake manifold and any particles of liquid fuel-which might have come through the .carburetor in the air stream have been thoroughly atomized by the action of the blades.

Upon leaving impeller 23, the gases are deflected radially outward into passages 20 and 2| where the well known diifusion action takes place and thepressure of the mixture is increased. The high pressure mixture which is thus delivered to the interior 2| of intake manifold 5,

is then distributed to the cylinders of the engine through suitable ducts or intake passageways indicated at 23. 7|

The embodiment of the'inv'ention shown in Figs.' 4 and "comprises a multl-stage supercharger including. an impeller and a deflector which, in the form shown, are housed and supported in a manner similarto thatshownin Fig. 1. In this embodiment, however, in placeof the single group or propellers shown in Fig. 1

- there is preferably provided a pluralityof'groups f .in series, closely adjacent one another,;each

theblades in each group, corresponding genergroup being similar tothat shown in Fig. 1, but there being preferably a variance in the sizes of ally to the. variation in cross-section of the casing I. As shown there are three sizes. of the propellers, the smallest being located'adjacent the intake 22 from the carburetor and the large' st adjacent diffusing passageway 2|.

. The variations in sizes lust referred to cor'respond (as-has been stated) -to the variations in is.-especially well adapted for use as a supercross-section of easing-.3. These variations are in turn dictated to a large extent by the size and location of the passageway 22 and the member].

In cases where ,conditionswill permit, it may be found more advisable to 'mploy an entering passageway of 'a shape so ewhat as indicated at 42 in Fig. 6, and to vary the ofthe pro- .1 pellers accordingly, as. indi at d at 1 K-fi-fi pelle'r assembly which mixes, imparts a velocity to be described hereinafter,

By the use of the larger number of propellers shown in Fig. 4, a substantial increase in velocity and pressure is attained} which increase'makes it possible, in many installations, to eliminate the centrifugal impellers shown at 23 in Fig. 1;"

-the'deflector Nbeing substituted therefor in the embodiment of Fig. 4. I When this is possible,-

an important saving in manufacturing costs is effected since the'cost of making an impeller such as that shown at 23 is much greater than the cost of making the blades II which can be .cut, stamped, or formed in other suitable manner of sheet or other material.

This deflector 23' comprises a frusto-conoidal shaped member, keyed to the shaft 6 so as to be rotatable therewith, and serving to deflect the fluid or mixture leaving the impeller blades with high axial velocity radially outward into diffusing passageway 28, from whence it passes into intake manifold 5.

.The advantage of the arrangement shown in Fig. 6 is that a relatively large inlet is provided, the cross-sectional area decreasing as the fluid is propelled inwardly toward the member 41 (corresponding to the member 23 in Fig. 1, or the member 23' in Fig. 4). There is thus obtained a Venturi effect which insures a relatively high increase in velocity. At the same time it is preferable to vary the pitch of the,.,successlve blades in such manner that the inflow will be directed along the, best possible path for effecting the maintenance of proper velocity during the passage into the narrower portion of casing A2. The construction indicated in Fig. 6 may of course beemployed with the embodiment of Fig. 1 or that of Fig. 4.

At Fig. 7 is illustrated a form of entrance differing from that of Fig. 6 in that it provides a chamber 42' wherein the incoming, fluid may build up a reserve volume and pressure ahead of the first propeller 40'. thereby insuringagainst too great a decrease in flow or'pressure as a result of a sudden unusually great draft exerted through the supercharger. Thus the chamber 42' is in effect a pressure reservoir which compensates for fluctuations in the flow.

It has been found desirable to locate the propellers 46' as Mass s. was the largest blade positioned mat, and ar a-poin't where maximum benefit, as regards'velocityand pressure, canbe obtained.

In Figs. 1,5, may be seen that the s adiacentpropellers 15 degrees'apart and-that asjeach individualpropeller'has four blades, any 'two propellers which are separated by live intervening ones have their blades lying in the same radial plane- Thisarrangement of 10 the propellers in sets of six provides a helical path between the endsfof the propeller blades and the .Ihere is thus disclosed by the present invenjtion'a novel form of fluid pump or compressor which is adapted to deliver large quantities of fluid at relatively high pressures. The invention charger for internal combustion engines, since it provides in a unitary structure, light of weight,

compact and easily assembled, a device which performs the combined functions of a difluser and a supercharger with a'high degree of efficiency, and which includes a novel combination of impellers as'well-as a novel and inexpensive form of imto; and increases the pressure of the fluid mixture received from the carburetor." It is also adapted for use in ventilating andv hydraulic systems.

1 It will be obvious that the invention is not limj tied to the form shown in the drawings but is capable of a variety of mechanical embodiments. For example any suitable type of drive for the shaft 85 of a supercharger may be substituted for the speciflc arrangement shown, and if desired, as pointed out above, the plan form. of the propeller blades .may be different from that disclosed in the drawings.- Moreover, it is to be understood that the 40 term propeller as used herein is to be construed sufliciently broadly to cover any means for effecting or facilitating the movementof the fluids, and the propeller may, if desired, be so formed as to have one or any suitable number of blades and may in certain instances be limited to the use of a single propeller. It will also be understood that the fluid pump or compressor, when used with an engine, may be located in the intake system at other than the point illustrated, as for example between the carburetor and the air inlet.

Various other changes which willnow appear to' those skilled-in the art, may be made in the form, details of construction and arrangement of the parts without departing from the spirit of the invention, and reference is therefore to be trance easing, said propellers having only slightly less length than the diameter of the tubular casing and arranged to have each propeller of one set fall within the same radial plane as a'corresponding propeller of another set, whereby a helical fluid path is formed. between the ends of. the propellers and the interior of the'casing. 1

2. A fluid pump comprising a chamberhaving a tubular fluid entrance casing, an impeller hav- 7 ing'a shaft rotatably supported in the chamber. a. plurality of staggered multi-blade contiguous propellers in said tubular casing, each propeller being angularly displaced in the same direction 3. A fluid pump comprising'a chamber having a tubular fluid entrance casing, an impeller in the chamber, a plurality oi staggered multi-blade contiguous propellers in said tubular casing, each propeller being angularly displaced in the same direction from its adjacent propeller, the pitch of the respective propellersv being diflerent and increasing toward the discharge end of the casing and the number of the propellers being great enough to cause at least three propeller blades to lie in the same radial plane, and a shalt common to the impeller and each of the propellers for rotating the same.

4. A fluid pump comprising a chamber having a tubular fluid entrance casing, an impeller having a shalt rotatably supported in the chamber, a plurality 01 more than two sets oi contiguous propellers in the entrance casing, said propellers each having a plurality of equally spaced blades, saidpropellers being angularly displaced in sequence and having the pitch oi! each propeller increased as they progress toward the discharge end or the casing, the angular displacement being constant and having a value such that the product oi the angle by the number of propellers in each set is equal to the angle between individual blades on each propeller, and means for driving the impeller and the propellers.

CLINTON H. HAVILL. 20

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