US2336476A - Rotary vane pump - Google Patents

Description

Dec. 14, 1943. F, c. FULCHER ROTARY VANE PUMP Filed May 9, 1941 4 Sheets-Sheet l Dec. 14, 1943. F. c. FULCHER ROTARY VANE PUMP I 4 Sheets-Sheet 2 Filed May 9, 1941 ATTORNEY 4 Sheets-Sheet 3 Dec. 14, 1943. F. c. FULCHER ROTARY VANE PUMP Filed May 9, 1941 Dec.- 14, 1943. F. c. FULCHER ROTARY VANE PUMP Filed May 9, 1941 4 Sfieets-Sheet 4 Fig.1].

k M2 M y B Patented Dec. 14, 1943 2 ,336,476 ROTARY VANE PUMP Frank Christian Fulcher, Grange-over-Sands, England Application May 9, 1941, Serial No. 392,700

In Great Britain May 20, 1940 I 4 Claims. (01. 183-36) The present invention relates to rotary vane pumps and particularly, although not exclusively, to pumps of the kind in which the vanes are mounted to rotate within a working chamber and to pass through slots in the wall of a barrel-like rotor so as to project inside and outside the barrel which also rotates within the chamber abcut an axis eccentric to that about which the vanes rotate, so that a relative sliding movement between the vanes and the rotor is produced when therotor. and the vanes turn and the ends of the vanes are carried round the peripheral wall of the working chamber. The invention is especially suited to high speed pressure pumps for use as superchargers or blowers on aircraft for charging the occupied interior of the aircraft with air at a of this invention consists in supporting the rotor Pump casing in the path of the discharge of the air from the working chamber. Another feature beyond the barrel by a shaft-like or journal-like the oil separator being then secured to the shaft;- in such extension and the outlet port from the working chamber being arranged to convey the discharged air through said extension to the outlet from the pump casing by way of such oil separator. This is especially convenient, when, as is preferred, a single rotor shaft is supported by two greater pressure than that of the surrounding atmosphere, as, for example, is necessary at high a1titudes,or foruse in the operation of de-icing equipment.

In dischargingcompressed air into the crew or passenger accommodation in aircraft to provide a more comfortable pressure of air therein it is important to avoid the contamination of air with oil or other media used for lubricating the pump and in supplying air from the pump to the de-icing equipment it is also necessary to avoid such contamination since oilhas a deteriorating action on the rubber of the de-icing'equipment. In other cases also it may be objectionable to discharge oil-laden air from the pump. In any case where bearings in order to counteract, the cantilever load on the barrel, since the space between these bearings provides convenient accommodation for the oil separator without substantially increasing the weight and bulk of the pump. The use of a rotary or centrifugal separator is especially advantageous in this connection because I can take advantage of the high speed of rotation of the rotor shaft to attach to that shaft one or more elements of the rotary or centrifugal separator.

- Alternatively the separator element or elements may be geared to the shaft, especially ifvit is desired further to increase the speed of such elements. I

There are various classes of barrel-rotor pumps to which the present invention can be applied. In

some forms the vanes pass from one side of the working chamber to the other, intersecting with- R. P. M. and pumps for supercharging may run at rather similar speeds; This normal speed may be considerably higher if the pump be driven by a motor or otherwise than direct from the engine.

It is moreover, an important desideratum in aircraft construction to keep any apparatus employed for these auxiliary duties as small and tion I provide a rotary oil separator within the in the barrel. In other forms the inner ends of the vanes slide around a tube or cylinder arranged centrally of the working chamber or, approximately so whilst the outer ends centrifuge against the inner wall of the working chamber. In some cases the vanes are constrained against centrifuging but do not pass completely through the barrel, e. g., the inner ends of the vanes may be provided with spaced intercalating eyes mounted upon a spindle centrally of the working chamber. In this latter class in some cases only the space in the working chamber around the barrel is utilised but I prefer to utilise not only that space but the space within the barrel and in fact a very convenient application of the present invention is to the pumps described and claimedin I my co -pending applications Serial Nos. 275,453-

to'the closed end of the barrel and the otherat or near the remote end of the rotor shaft. One port, or two ports which may be 'used alterna-"g tively may lead from the working chamber to an annular chamber formed in the extension of the casing around the shaft and between the bearings; and an outlet from the pump casingis also in communication with such annular chamber. This-outlet may be common to the alternative ports when these are provided. The oil separator is located in thi annular chamber.

My invention also comprises an improved form of apparatus for separating the lubricant .from the oil-laden air in which one or more annular ribs or ring members are arranged on a shaft to rotate at high speed inthe path of the laden air through a passage or chamber which is provided with inwardly extending baffles which compel the air to follow a sinuous course or multiple path through said passage over the rotating members. The apparatus may comprise a single baffie, when two ribs are provided this bafiie intruding inwardly between the ribs or ring members and compelling the air which has passed through or around one rotating ring member to fiow inwards towards the inner part of the next rotating ring member, but preferably a plurality of bafile members are provided which together form one or more annular channels into which the margin of the ring member or members intrudes. A single ring member or rib may be used where it may be made of large diameter so as to provide an effective surface area equivalent to that which I usually find requires more than one ring member.

The channel-forming baffle members may di- V e towards, or be locally thickened at, the inner edge so as to narrow the inlet and outlet to the channel. They may be provided with curved lips at their inner edges so' as to form annular traps tending to confine separated oil to the channels.

"gether on the shaft and frictionally or otherwise suitably fixed thereto or they may be integral with a common central sleeve or with the shaft itself.

Another form of separator which is advantageous is one in which the rotary ribs or ring members are perforatedwith multiple holes, preferably arranged so that the walls project towards the inlet to the passage and provide sharp edges which scrub the air as it is thrown outwards on the rotating surface.

The holes may be in staggered relationship in the successive members so that the air is compelled to take a sinuous course through the passage or they may be arranged only in the marginal portions of the ring members which extend radially beyond the inner edge of the baflle .members so that the air must follow the desired sinous path through the passage.

The margins of the ribs or ring members may be bent over or curved to throw back the air and if desired, these margins may be provided I may provide an annular chamber around the wall of the passage and ducts through the latter topermit the oil to drain out of the channel or channels.

The leading baffle may provide a restricted inlet in the form of a series of holes or an annulus and the rearmost baffle may provide a restricted outlet of annular form or in the form of a series of holes.

The bafiles may be arranged to be clamped together to' form the channels, which'may be half-circular in section or U-shape, and the passage wall, and the margins of the baffles may be stepped so that they interfit. An alternative form of channel which assists in collecting the oil in the bottom of the channel irrespective of the position in which the pump is fixed is one having an acute angled base.

The ribs or ring members may be radial or approximately radial, but in some forms it is convenient to dish these members. They may be unperforated, in which case they are arranged to leave ample space with the bottoms of the channels so as not at this region unduly to impede the flow of the air along the passage. They may be separate members each having a central hub and arranged to be assembled towith a series of teeth, the alternate teeth of the circumferential series being bent-back in the reverse direction.

These perforated ribs or ring members or even the unperforated variety, may be clamped together by spacing rings in such a manner'as to rotate with the shaft.

In the forms of separator described where two or more ribs or ring members are provided, the air fiows over these members in series, but-in accordance with another form of the invention the fiow is in parallel; This may be achieved for example by providing the margins of the baiiie members with one or more recesses, slots or holes andarranging the baflies and ring members so that no substantial quantity of the air can reach the outlet of the passage except by passing through one or other of the gaps between the ring members and the baflles. It is advantageous in this form to make the ring members and the bafiles of such form that the rotating and non-rotating surfaces can be brought into closer relationship, thereby compelling the laden air to pass through fine gaps or clearances in which it is subjected to considerable friction, the fiow, under suitable pressure, being inwards, i. e., opposing the centrifugal action.

In order that the present invention may be the more readily understood, reference is hereinafter made to the accompanying drawings, in which: Fig. I is a longitudinal sectional elevation through a pumping apparatus in which the separator is built in; Fig. 2 is a lonigtudinal sectional elevation at right angles toFig. 1 and Fig. 3 is an end view of the apparatus.

Fig. 4 is a lonigtudinal sectionof a modified form of separator and Fig. 5 is an end view of the inlet thereto and serves also to illustrate the inlet to the first form of apparatus. Fig. 6 is a longitudinal section of another form of separator employing perforated rotary ring members and Fig. 7 is a face view of one-half of one of the ring members.

Fig. 8 is a part longitudinal section through a form with a modified construction of baffle.

Fig. 9 is aside view and Fig. 9a a face view of a modified form of ring member.

Fig. 10 is a longitudinal section of another modification, and Fig 11 is a transverse section thereof.

As the pump apparatus illustrated is fully described in my co-pending applications aforesaid,

I shall only describe herein those essential parts of the pump which will enable the present invention to be fully understood.

Briefly the pump comprises a casing I, providing a working chamber 2 in which rotates the barrel portion 3 of a rotor, the latter being. supported at one end only by a shaft 4 which projects from the closed end 5 of the barrel, the other end of which is open and is arranged to rotate with a fine ring clearance in an annular groove 6, .in the end wall component I of the working chamber. The other end of the barrel runs out of contact with the cylindrical wall 3 of the casing extension 9 and also makes a fine ring clearance ,therewith. Vanes ID are provided with intercalated hinge eyes H which are rotatably supported by a spindle l2 securely fixed in the end wall fl, l3 of the casing, the component l3 of the end wall being spaced from the inner component 1 so that between the two components a chamber is formed whichis divided by a partition l4 into two conduplicated recesses, the ends |5, |6, H and I8 of which are arranged to co-operate with ports i9, 20, 2|, 22 disposed across the inner component I so that the two ports 20, 2| lie within an area corresponding to the space inside the rotor barrel, and thus communicate therewith, while the other ports I9 and 22 lie outside the groove 6 in the inner component 1 and the outer peripheral wall of the rotor barrel and communicate with the space outside the rotor barrel. Each of the outer ports I 9 and 22 of the inner wall register with one end, viz., |5 and I8 of the corresponding conduplicated recess while each of the inner ports and 2| registers with the corresponding opposite end I8, I! of the recess. With this porting system, both the inside and outside of the rotor barrel are effectively used in the pumping operation, when the vanes, which pass through oscillating bearing pins 23 in the barrel wall, and the barrel, rotate.

The rotor shaft is supported by spaced bearings, in this example, ball bearings, 24 and 25 and it rotates at high speed as herebefore explained.

The pump is lubricated through inlet 26, duct 21, regulating device 28, duct 28 the fine annular clearance 29 whence the lubricant either enters the working chamber dir'ect as a fine mist or passes along ducts 29 in the closed end wall of r the barrel.

For the purposes of this invention, the air discharged from the pump is required to be freed from lubricant particles as the discharge of oil-- contaminated air into the cabin of the aircraft or to the de-icing tubes is to be avoided.

For this purpose the air is discharged from the working chamber by an end port 30 or by one of two end ports selectively and then by way of the radial passage 3| into an annular passage 32 around the shaft of the rotor and between the two ball bearings, and in this passage means are races of the ball bearings are spaced by two tele- I scoping sleeves 33 and 34 frictioned or otherwise secured together and'on the shaft so as to rotate therewith. The outer sleeve rotates with a fine clearance within a sleeve 35 which is fixed between the outer race of the bearing 25 and the end of the cylindrical wall 36 of the separator passage and which seals the passage from communication with the exterior of the apparatus by way of the space between the two races of the outer ball bearing 25.

The outer sleeve has a series of ribs 31, which in this case are unper forated, and these ribs intrude into channels 38 formed by baflles 39 extending inwards from the wall 36, the ribs having sufiicient clearance with the bottoms of the channels not to impede substantially the flow of air along the passage. The baffles extend in-- wards beyond the outer peripheries of the ribs and the inner edges of the baffles are thickened so as to narrow down the space between the inner edge of the battle and the adjacent face of the rotating rib. The leading baffie provides a constricted inlet to the passage 32, e. g, by way of a series of holes 40 and the last bafile provides a constricted outlet 4| from the passage to the annular chamber 42 and outlet port 43. The inlet and outlet may be flared.

Around the wa1l36 is formed an annular chamber 44 which communicates with the channels by way of holes 45 and with a drain 46, and preferably a series of such drains arranged around the periphery of the casing extension, communicate with such chamber, so that the pump can be disposed in any suitable angular position.

The operation of the apparatus is as follows:

When the pump is running the ribs 31 rotate at high speed in the path of the oil-laden air which enters the passage 32 from the working chamber by way of the end port 30, radial passage 3| and the inlet 40. The heavier oil particles are thrown outwards against the wall of the channels 38 which trap the oil. If the external diameter of the'rib be sufficiently great, one rib and one channel will suifice, but for greater radial compactness, and to utilise the existing proportions of the pump apparatus more to advantage, two or more such ribs. in the particular example,

four, and a corresponding number of channels are employed, and the baffles compel the air which has passed around one rib to flow towards the inside of the next so that the air which may still contain oil particles is subject to a similar centrifugal action by the next and subsequent ribs.

Moreover the oil-laden air is given an elongated Oil collected or.

path through the passage 32. trapped in the channels escapes through on of the ducts 45 into the annular chamber 44 and thence outwards by whichever drain lowermost and air separated from oil flows out through the outlet 4| of the passage, the annular chamber 32 and the outlet 43. The narrow gaps between the ribs and the inner edges of the ballle compel the air to move in close proximity to the inner parts of the rotating ribs so that the oil has an excellent chance of being brought into contact with the rotating rib and thrown outwards to the bottom of the channel. The thickened inner parts separated is returned to the engine. An adjustable needle valve may be used, or a non-return valve may be desirable which is responsive to the back pressure or pulsations of the engine gases.

In lieu of making the'bafiles integral with a common cylindrical member and the ribs integral with a sleeve or with the shaft, the baflle members may be separate components secured by bolts 41, as shown in Fig. 4, and the ribs may be separate components, each provided with a central hub portion 48, the hubs being brought one behind the other around the inner sleeve 33 and being clamped thereagainst in frictional connection therewith by the short outer sleeve 34. The bafile members may be stepped at 49 in order to interfit. Fig. 4 also shows a modified arrangement of the draining ducts; one on each side of the channel instead of a single one at the bottom of the latter as in the previously described form.

My apparatus may be designed to have a scrubbing action on the oil-laden air. Accordingly, as shown in Figs. 6 and 7, I use, in the place of the unperforated ribs previously described, the ring members 50 which are provided with multiple apertures punched out from the ring member so as to provide projecting walls directed towards the oncoming stream, i. e., the holes are somewhat in the form of those in an ordinary carrot or nutmeg grater, the sharp edges being foremost. While being thrown out over the surface of, the ring member, the oil laden air is scrubbed and separation is facilitated. As shown, the holes may be in staggered relationship in the successive ring members so as to prevent any of the air or any substantial part of it, by-passing the trap channels, or alternatively, all the holes may be confined to the marginal areas of the members which lie outside the inner edges of the baflle members.

In this modification, the inner edges of the baffle members are shaped to form on each side of the baffle an annular channel 52 which on the one hand helps to trap oil and on the other helps to deflect back the air onto the rotating ring members. This channeling of the baffle members may be equally applied to the unperforated form of separating ribs or ring members.

If desired the ring members may be dished, or cupped, in order to defiect the oil-laden air outwards.

It is advantageous, for facilitating assemblage of the separator, to make the leading baflle with a central hub 53 which is positioned between the two sleeve components, although not so as. to

have any substantial rubbing contact therewith. For this reason an inlet to the passage by way of holes or slots is shown, but otherwise an annulus may be used.

In Fig. 8 an alternative form of channel is provided having an acute-angled base formed by curving one wall of the channel and leaving the other in an approximately radial plane.

The edges of the rotating ring members may be curled somewhat so that the air instead of being thrown oil into the trap radially has its direcis given an obstructed or tortuous passage through the casing extension to the outlet in a comparatively cold region of the pump away from the working chamber and therefore the depositing of the oil content of the air on the rotary 5 surfaces is facilitated and it can drain into a suitable receiver or outlet, the air being broken up as much as possible in the course of its flow through the separator so as to bring it into contact with oil depositing surfaces of as large an area as is possible.

In the previously described arrangements, the air passes over the rotary ribs or ring members in series, but I have also illustrated, see Figs. 10 and 11, a form in which the air flows in parallel over the rotary members. In this form the baflle members 39 are marginall recessed at 56, or in other words they are provided with two or more tongues or projections 51, e. g., four, by which they are bolted to the casing, the recesses 56 between the tongues allowing the air to take an inward path through any one of the fine gaps or clearances between the rotar ring members 59 and the fixed baflles 39. The air can only leave by passing through one or other of the said fine gaps or clearances. Although coarse spacing of the parts is shown the relatively rotating surfaces may be nearly but not quite in contact, e. g., they may provide fine slots of the order of /100" in width. The fixed baflles or blades may have inner recesses 60 or otherwise be so shaped internally as to provide edges extending obliquely across the width of the bladelike ring plate, and thereby forming regions where the clearance is enlarged to that afforded by the spacing of the adjacent rotary ring members. With this arrangement aflushing action is achieved of the air over the surfaces of the rotating members. The latter and the stationary members are preferably made as thin as is practicable consistent with possessing strength and rigidity.

The sleeve carrying the baffle members or the separate end baffles may be held from rotation frictionally or by pinching in the extension of the casing. 1

In the form shown in Figs. 6 and 7 the perforated ring members should preferably make as fine a clearance as possible with the bottom of the channels.

In this case the total area of the perforations in each perforated ring member should be equal to or greater than the delivery pipe capacity. If a predetermined clearance is left between the ring members and't'he channel the total area of the perforations may be decreased, e. g., by reducing the number of perforations.

What I claim is:

1. A high speed rotary apparatus for delivering a gaseous medium free of lubricant gathered by the medium during its passage through the apparatus, comprising a casing member providing a work cylinder and an elongated laterally extending aperture communicating with the work cylinder adapted to journal a shaft, an open ended rotor barrel rotatable in said cylinder, said barrel having a shaft member of reduced diameter extending from its closed end into said elongated aperture, the clos d end wall of said barrel effectively closing off communication between said work cylinder and said laterally extending aperture, axially spaced antifriction bearing means in said elongated aperture for journaling said shaft whereby the said rotor barrel is rotatably supported cantilever fashion in said work cylinder, vane members in said work cylinder coactively related with said rotor barrel and with said work cylinder to deliver gaseous medium on rotation of the barrel, a conduit for conveying the medium from the work cylinder around said closed end of the barrel and into one end of the space between said axiallyspaced journal bearings, a delivery conduit communicating with the other end of said space between said axially spaced bearings, and centrifugal means in the space between the said axially spaced bearings for removing lubricant gathered by the medium during its passage I through the work cylinder, comprising means rotatable with said shaft so that the space between the said bearings is utilized as a separating chamber and the speed of the rotor shaft utilized to effect the removal of the lubricant from the gaseous medium as it passes through the chamber to said delivery conduit.

2. The combination set forth in claim 1 in which said centrifugal means in the space between the axially spaced bearings comprise-outer and inner sets of intedigitating fin elements arranged in spaced planes perpendicular to the axis of said shaft, the said outer set being secured to said casing and the inner set being" secured to and rotatable with said. shaft.

are perforated and the spaces between the fins of said outer set form collecting chambers, and conduit means also in the said casing and communicating with said collecting. chambers for conveying collected liquid away therefrom.

4. 'I'he combination set forth in claim 1 in which said centrifugal means in the space between the 25 3. The combination set forth in claim 1 in which said centrifugal means in the space between the axially spaced bearings comprise outer and inner sets of interdigitating fin elements arranged in spaced planes Perpendicular to the axis of said shaft, the said outer set being secured to said casing and the inner set secured to and rotatable with said shaft and in which the fins of the said outer set are formed with curved inner edges forming collecting chambers, and conduit means in the said casing and communicating with said collecting chambers for conveying collected liquid away therefrom.

FRANK CHRISTIAN FULCHER.

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