US2356243A - Feeding device for pumps - Google Patents

Description

g 1944' M. w. I -IUBER I 2,356,243

' FEEDING DEVICE FOR PUMPS Ihwe ntot Qttorngs Patented Aug. 22, 1944 DEVICE FOR PUMPS Matthew- W. Huber, Chicago, Ill., assignor, by mesne assignments, to The New York Air Brake Company, a corporation of New Jersey Application November 12, 1942; Serial No. 465,362

10 Claims.

This invention relates to pumps and particularly to means for feeding the intake of a high pressure pump where ordinary suction effects are unreliable or inoperative.

In applicants prior application, Serial No. 462,563, filed October 19, 1942, there is described and claimed a single-acting multicylinder. pump in which the cylinders are parallel and the plungers are actuated by a swash plate. This pump will operate at speeds above 4000 R. P. M. against head pressures of 2000 lbs. per square inch, and was intended for use in the regulating mechanism of a particular variable-pitch propeller for aircraft. In this environment the pump revolves in a circular orbit whose radius is aboutfive inches at a rate of over 1500 R. P. M. This follows from the fact that the pump is mounted eccentrically in a rotary annular shell which houses the regulator and the pump and serves as a reservoir for the oil which is pumped. Even if this shell, which turns on a normally horizontal axis, be filled to the diameter when the device is at rest, the oil will fioW by centrifugal force into a rather shallow annular bath, when the device runs, because of a centrifugal tendency which is many times the force of gravity. V

Since the pump cannot be submerged in this annular bath and since the pump inlet is necessarily between the surface of the bath and the center of rotation of the shell, centrifugal forces so resist the entrance of oil into the pump as to preclude the use of an ordinary suction connection.

According to the invention a rather'simple pocketed wheel or runner is used tolcarry oil from the bath to the pump intake. The use of such a runner is facilitated by associatingwith it a non-rotating concentric shroud so ported that the hydraulic pressure centrifugally developed in the oil bath causes oil to enter the pockets andcentrifugal forces also urge the oil toleave the pockets and enter the pump intake. 'The runner maybe incorporated 'in the' gear" which drives the pump and this construction: saves weight.

This pocketed pump feeder is effective to feed unfailingly from a very shallow bath. This permits reduction of the oil charge to less than half that heretofore necessary, with consequent saving of weight, and substantial elimination of leakage formerly occasioned by submergence of certain packed joints when the device was at rest. These considerations are of obvious practical importance in the aircraft art.

V The accompanying drawing illustrates the invention by way of example as incorporated in the particular pitch regulator structure for which it was designed. No details of the pitch regulator are the invention of this applicant, and only such parts thereof asare necessary to description of the construction and utility of the pumping unit, are shown.

Fig. 1 is a fragmentary vertical axial section of the annular rotating housing which encloses the pump ,(shown part in' section, part in elevation),

the feeder unit (shown in section) and the regulator (not shown).

Fig. 2 is afrag'mentary section on the line 22 of Fig. 1.

Fig. 3 is an elevationrof the pocketed face of the pump driving gear. i

Fig. 4 is a fragmentary section on a greatly reduced scale intended to indicate how the pump revolves with the housing and how its gear is driven by the fixed ring gear.

In the drawing the numerals 6 and 1 identify fixed hub parts about which the annular housing comprising two separable components 8 and 9 rotate: The parts indicated generally at H and I2 are seals to resist the loss of oil. A fixed ring gear is, formed in the part 6, its teeth being indicated at 13. Y The rotating parts 8 and 9 form a hollow annular trough and with the parts 6 and I enclose an annular space generally indicated by the numeral i l. This space serves as a reservoir for oil and also houses the pump and some components of the regulator not here material.

A pump for a propeller regulator would be of the positive displacement type. The particular pump illustrated has nine single acting cylinders parallel With and arranged in circular series around the drive shaft. The plungers which work in these cynnders are actuated by a swash plate fixed on the shaft. 1

T e pump housing made in two sections l5 and Hi with mating flanges ll and It. The flange 'Il engages a m 0 unt ill to which it is bolted. The bolts are not visible in the drawing. When the pump is so mounted the discharge passage H in the portion [5 of the houslng communicateswlth thehigh pressure passage 22 in .a part carriedby theannular housing portion 8. A compressed gasket 23 or oil resisting rubberlike material produces the necessary seal.

The drive shaft or the pump 15 indicated at 24 and carries at its outer end a drive disc 25. Fixed to the shaft 24 is a swash plate 26 which turns in a bearing bushing 21 mounted in the portion vention is concerned, is that the liquid to be pumped (in this case, oil) enters the pump housing l6 by way of port 33 (see Fig. 2). Since this port 33 is on the side toward the primary axis of. rotation, any oil which enters through the port 33 will be retained within the housing until it is.

discharged by the pump and will be under a pressure head developed by the centrifugal effect.

The portion l6 of the pump housing has an external configuration intended to facilitate delivery of oil to the port 33. The form of the right hand end of the housing I6 is best shown in Fig. 1. It will be observed that there is an encircling flange 34 which lies in a plane normal to the axis of the shaft 24 and which carries a marginal rim 35 extending outward.

Fixed to the disc 25 and concentric therewith is a combined driving gear and carrier unit, generally indicated by the numeral 36 in Fig. 1, and shown in detail in Fig. 3. The member 36' is concavo-convex, has peripheral gear teeth 31, and on its inner convex side has a series ofradial vanes 38, eight being indicated in Fig. 3. The number of vanes is subject to variation. Shrouding the ends of the vanes 38- and dimensioned'to make a free running fit within the marginal rim 35 is a rim 39.

Above the pump intake 33 a discharge port 4| (see Fig. 2) is formed in the flange 34. Diametrically opposite this discharge port 4| is'an inlet port 42-.- The oil level in the rotary housing 8', 9 is such that when the housingis rotating at normal speed, the oil is distributed within the housing in an annular bath which will-submerge the inlet port 42; The bath can and commonly will be somewhat deeper but all that'is strictly necessary is to keep the port 42-submerged, so'that only oilwill enter the-runner 3B, filling the buckets or spaces-between successive vanes 38;

A deflector 43 is mounted on the portion l6 ofthe pump housing for the purpose of enclosing a passage from the discharge port4|-to the pump intake 33; The part-43-could be integral with the part I5, but for convenience in manufacture has beenconstructed as a'separate'part as indicated in the drawing.

In one respect the runner generally indicated by the numeral 36 is an impeller unit. In another; it is a-pocketed carrier. Whichever way it be regarded, the runner 36 is shrouded by-the flange 34 with its marginal rim 35 so that oil enters the pockets in the carrieronly through the port 42 and is discharged from thesepockets through the port4l. 1

1 To avoid confusingthe drawing, the oil which isa necessary factor in the operationof thepropeller control has-been omitted-from Figs.- 1 and 2. Reliance is placed on-Fig. 4 to describe the movements of theparts and the level of the-oil.

The housing 8. as viewed in Fig. 4, rotates about the axis A which is the primary axis. The runner33 rotates about -a-secondary axis B which is parallel with the axis-A- and which is the axis of-rotation ofthepumpshaft'24r Because the pump is mounted in the rotary housing 3, 9, the pump and consequently the axis B revolve about the axis A. The oil level is designated in Fig. 4 by the broken line C. When the rotary housing 8, 9 is running at a normal rate, say 1500 R. P. M., the oil flows into an annular bath whose level is indicated at C'. This bath is under substantial hydrostatic pressure developed centrifugally.

The combined runner and gear 33 rolls around the ring gear l3 and in actual practice has a rotary speed about the secondary axis of the orderof 4000 R. P. M. The displacement pump operates against a head pressure which is normally 1500 lbs. and may rise to 2000 lbs. per square inch. The hydrostatic pressure in the oil bath at C (Fig. 4) is effective to develop an active entrance tendency. on the oil adjacent the inlet port 42.

Consequently the pockets between the vanes 38 fill with oil. This oil is swept around until the pockets open to the discharge port 4|. At this time the centrifugal effect incident to rotation about the primary axis A imposes a substantial discharging tendency. This tendency is modified by centrifugal effects developed by the rotation of the runner 36 about the secondary axis. Thus centrifugal effects cause oil to flow through the discharge port 4| and keep the pump intake 33 flooded. The oil delivery capacity of the runner 36 materially exceeds the pumping capacity of, the positive displacement pump which in practice is somewhat less than'0.1 cubic inch per revolution, but the runner 36 is impositive in action and therefore delivers only such oil as the positive displacement pump requires. The charging runner 36 improves the performance of the positive displacement pump, because itdelivers to an oil retaining intake chamber which is under a centrifugal hydrostatic pressure, and thus makes it possible to develop a positive pressure onthe intake which improves the volumetric efficiency-0f the displacement pump.

In the regulators as originally designedythe space M was filled to the level of the axis A when the device was at rest. This brought the oil above the seals H and I2, when the device was not running. The use of the runner to supply the intake to the displacement pump not only ensures proper feeding of' this pump even when the-oil level is low, but permits the normal oil level in the housing to be lowered to such an extent'that it isnever above the packed joints II or 12.

The incorporation of the runner in the driving gear and the use of portions of the displacement pump housing as a shroud produce a peculiarly compact design which is considered highly advantageous. However, the pump with its charging runner could be usedin other environments in which different arrangements of the components would be preferred. In such case, it might not bedesirable to combine the runner and the driving gear. The invention maybe-used to-advantage in any relation inwhich adverse force reactions, such as the centrifugal force discussed above, render the use of a simple suction eonnection impracticable. W

While the invention produces a very compact construction in combination-with the particular parallel cylinder pumpof my; prior-application; the runner arrangement could-be used-to supply pumps of other types. It-follows; that the embodiment above described in considerable detail is-illustrati-ve and notlimiting.

I claim:

1. Means for delivering liquid-' centripetally from a confined annular bath of liquid-which-rctates about a primary axis-at sufiicient angular velocity to generate substantial centrifugal'force, comprising in combination a pocketed carrier revolving about the primary axis and rotating about a secondary axis displaced radially therefrom; and a shroud coacting with said carrier to close the pockets therein and with respect to which the carrier rotates, said shroud having an inlet'portsubmerged in the bath of liquid and communicating with "successive pockets in the carrier and any outlet port nearer the primary axis and' also "communicating with successive pockets, said ports being so located that the centrifugal force generated by rotation about the primary axis urges liquid into the inlet port and out of the outlet port.

2. Means for delivering liquid centripetally from a confined annular bath of liquid which rotates about a primary axis at sufficient angular velocity to generate substantial centrifugal force, comprising in combination a pocketed carrier revolving about the primary axis and rotating about a secondary axis displaced radially therefrom; a shroud coacting with said carrier to close the pockets therein and with respect to which the carrier rotates, said shroud having an inlet port submerged in the bath of liquid and communicating with successive pockets in the carrier and an outlet port nearer the primary axis and also communicating with successive pockets, said ports being so located that the centrifugal force generated by rotation about the primary axis urges liquid into the inlet port and out of the outlet port; and a positive displacement pump having an intake fed by said outlet port.

3. The combination of means providing a rotary annular liquid-retaining trough which turns at sufficient speed to distribute the liquid by centrifugal force in an annular bath; a pump rotating with said trough-forming means and having an intake which, at least at times, is radially inward from the surface of the annular liquid bath; shrouding means having an inlet port submerged in said annular bath and an outlet port communicating with the pump intake; a carrier coacting with and moving relatively to said shrouding means and having at least one pocket which communicates with said ports in alternation; and means for driving said pump and carrier.

4. The combination of means providing a rotary annular liquid-retaining trough which turns at sufficient speed to distribute the liquid by centrifugal force in an annular bath; a pump rotating with said trough-forming means and having an intake which, at least at times, is radially inward from the surface of the annular liquid bath; shrouding means having an inlet port submerged in said annular bath and an outlet port communicating with the pump intake; a carrier coacting with and moving relatively to said shrouding means and having at least one pocket which communicates with said ports in alternation; and means rendered effective by the rotation of the trough to drive said pump and carrier.

5. ihe combination of a fixed ring gear; an annular liquid-retaining trough mounted to rotate about the axis of said ring gear at sufiicient speed to distribute the liquid by centrifugal force in an annular bath; a positive displacement pump rotating with said trough-forming means and having a driving gear meshing with said ring gear, said pump having an intake which, at least at times, is radially inward from the surface of the liquid bath; a pocketed carrier turning 00- axially' with :said pump-driving gear; and a shroud coacting with said carrier and having, an inlet port submerged in said annular bath and an outlet port arranged to direct liquid, discharging therethrough by centrifugal force, into said pump intake.

6. Thev combination defined in claim 5 in which the pocketed carrier comprises a cupped disc with substantially radial vanes and the shroud-includes a plate substantially normal to thetaxis of rotation of the carrier and in which the inlet and outlet ports are formed.

7. The combination of means providing a rotary annular liquid-retaining trough which turns about a primary concentric axis at sufficient angular velocity to distribute the liquid in an annular bath under substantial centrifugally generated hydraulic pressure; a vaned runner revolving about the primary axis and rotating about a, secondary axis so located intermediate the primary axis and the annular bath of liquid that the path of the vanes enters the bath; and a liquid confining shroud revolvin with the runner, but fixed relatively to the secondary axis and runner, said shroud having an inlet port so located as to permit entrance of liquid from the bath between the vanes of the runner under said hydraulic pressure, and an outlet port so located as to induce discharge of said liquid from between said vanes by forces generated by both rotations.

8. The combination of means providing a rotary annular liquid-retaining trough which turns about a primary concentric axis at sufficient angular velocity to distribute the liquid in an annular bath under substantial centrifugally generated hydraulic pressure; a vaned runner revolving about the primary axis and rotating about a secondary axis so located intermediate the primary axis and the annular bath of liquid that the path of the vanes enters the bath; a liquid confining shroud revolving with the runner, but fixed relatively to the secondary axis and runner, said shroud having an inlet port so located as to permit entrance of liquid from the bath between the vanes of the runner under said hydraulic pressure, and an outlet port so located as to induce discharge of said liquid from between saidvanes by forces generated by both rotations; and a positive displacement pump having rotary driving means turning with said runner, and having an intake fed by said outlet port.

9. Means for delivering liquid centripetally from a confined annular bath of liquid which revolves about a primary axis at sufficient angular velocity to generate a substantial hydraulic pressure head in the bath, comprising in combination, a disc which rotates about a secondary axis displaced radially from the primary axis and is formed with pockets in a lateral face; and a plate-like shroud which revolves about the primary axis but is fixed as to the secondary axis and coacts with said disc to close the open side of the pockets, said shroud having approximately diametrically opposed inlet and discharge ports which communicate with the pockets, the inlet port being so located as to be submerged in the bath and the discharge port being at a shorter radial distance from the primary axis than is the surface of the bath.

10. The combination of means providing a rotary annular liquid-retaining trough which turns about a primary concentric axis at sufficient angular. velocityto distribute. the liquid in an annular bath under substantial centrifugally generated hydraulic pressure; a vaned runner. revolving about the primary axis and rotating abouta secondary axisso. located-inter.- mediate the primary axis and the. annular bath of liquid that the path of the vanes enters the bath; a liquid confining shroud. revolvingv with the. runner, .but fixed relatively to. the secondary axis and runner, said. shroud having. an inlet portsoflocated as to permit entrance of liquid from the bath .between the-vanes of therunner 7 having rotary driving means turningiwith said runner, and. having an intake chamber fed by said outlet port, and so locatedflrelatively to the primary axis thatioil isretainedin'ithe chamber under a centrifugally developed pressure head [0 and is supplied under said head to the pump.

' MATTHEW W. HUBER.

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