US2545238A

US2545238A - Radial vane pump

Info

Publication number: US2545238A
Application number: US548334A
Authority: US
Inventors: Norman F Macmillin; Howard M Purcell
Original assignee: HPM Development Corp
Current assignee: HPM Development Corp
Priority date: 1944-08-07
Filing date: 1944-08-07
Publication date: 1951-03-13
Anticipated expiration: 1968-03-13

Description

March 13, 1951 N. F. MaOMlLLlN ET AL 2,545,238

RADIAL VANE PUMP Filed Aug. 7, 1944 3 Sheets- Sheet l lEl INVENTORS Norman F. Mac/mum,

? E /Iowan Puncgm I ATTORNEYS March 13, 1951 N. Fl MaGMILLIN ET AL 2,545,238

RADIAL VANE PUMP Filed Aug, 7, 1944 5 Sheets-Sheet 2 INVENTORS NORMAN F. MAcMlLLIM BY HOWARD MPURCELL,

4v ATTORNEYS N. F. MacMlLLlN ET AL RADIAL VANE PUMP 3 sheets sheet Filed Aug 7' 944 V INVENTORS NORMAN I. MACMILLIN,

BY Now/m0 MPURcELL, .9-

4 W ATTOR YS Patented Mar. 13, 1951 UNITED STATES PATENT OFFICE RADIAL VANE PU'MP Norman MacMillin and Howard M. Purcell, Mount Gilead, Ohio, assignors to H-P-M Development Corporation, Wilmington, DeL, a corporation of Delaware Application August 7, 1944,,SerialiNo.548,334

7 Claims. 1

This inventionrelatesitofluid.operable apparatus and, particularly, to fluid operable ,pumps or motors. More particularly still this invention relates to vanetypepumps or motors.

It is a primary object of the present invention to provide a vane pump .or motor in which the wearing action which normally takes place between the'ends of thesaid vanes-and a cylinder within which they are .movable is substantially eliminated.

It'is another object of this invention to provide .an improved construction "for a vane type pump or .motor .in which the various components are readily manufactured .to the necessary tolerances without the use .of special and expensive machinery.

.Itisanolther obiectto provide a vanepump or motor structure "in which thebearing load of the vanes -in .the rotor is reduced thereby to inhibit sticking .of .the vanes and excessive wear.

It is another object to provide a variable delivery vane pump embodying the foregoing .improvements.

These and other objects and advantages will become more apparent upon'reference to the following-description taken in connection with the accompanying drawings, in which:

Figure 1 is-a longitudinal section through a pump ormotor constructed according to this invention;

Figure .2 is a transversesection through the .pump ormotor and is indicated by theline'2-.2

on Figure 1;

"Figure 3 is a sectional view indicated by the line 3--'3 on Figure 2' and'shows the port in the cylinder block;

Figure 4 is aplan view taken over one .of the vanes of the pump or motor showing its relationship to thesguidewalls on either side thereof Figure 5 is a view of thepi'ston-Vane illustrating the action of 'the balancing surfacesthereof;

Figure 6 is a transverse view through a modi- ..fied structure showing areversible variable discharge type of pump constructed according to this. invention;

Figure 7 is a sectional view indicated by the line 1-1 on Figure 6 and shows a modified manner .of..retaining the .piston vanes in their, proper location; and

Figure 8lis a plan vie wover the, pistonvanein Figure 7 showing its ..relationship to :the guidewalls on either side thereof.

General arrangement A pump or motor constructed according-to this invention comprises, generally, a casing within which'is rotatably mounted a rotor having bores therein for receiving reciprocating vane --members. The vanemembersare..adapted toride on theinnersurface -of za-rcylin'drically bored lmem- 2 her which is eccentric with the said rotating member.

In order "to eliminate or inhibit the wearing of the vanes where they contact the cylinder wall, the vanes are provided with balancing areashy- .draulically-connec'ted so that the vane is continuously in .a state of hydraulic balance. When the vane is passing through a Working zone and one side thereof is under working pressure and the otherside thereof is underrsuction pressure, afirst balancingarea is hydraulically connected to the pressure side to balance Off the thrust therefrom whilea second balancing area is con- -nected with the suction side so that any thrust therefrom is balanced-off.

According to this invention, when the device is operated as a pump, the vanes are maintained in contact with the cylinder wall by centrifugal .force .as the rotating member is driven. If the deviceis to be operated as a motor it is necessary to urge the vanes outwardly by suitable yielding means such as springs, by hydraulic pressure or, by. a.mechanical actuator.

.The pump or motor may be made to have variable displacement by-arranging the cylindrically bored-member within the casing so that the relative eccentricity of the rotor .and the cylinder bore may be varied by any arrangement of suitable and well known controls.

The vane membersare preferably cylindrical, thus simplifying the machining thereof and also provide for a greater area of contact between the said vanelmembers and the 'bores in the rotor within which they reciprocate. This inhibits wear and provides for a more readily reciprocable vane.

Structural arrangement Referring more particularly to the drawings, the pump comprises a main body portion 5 0 which is hollow'to receive a rotor II and which is also bored to receive an antifr'iction bearing l2 within which the said rotor is journalled. The body .10 is engagedby a cover plate or closure member 1-3 which is secured in place'by any suitable means such as the screws Hi. 'The member l3 may be "flangedto provide amounting base for the pump "and, to this end,.may comprise the countersunk "screw :h'o'l'e's 15. Similarly to the body Ill, the member 13 is bored to receive an antifriction hearing which, together with the bearing I 2 serves as a support for the rotor H. The rotor 11 comprises a first member I! which has integral 'therewith the trunnion portion 18 adapted to be received within the bearing l2 and, a second :member H! which has integral therewith the trun- .nion portion :20 adapted to be received within the bearing I6. The member l9 also comprises .dfiven..-from-;any-suitabl :source.

The rotor members I1 and H) are secured together by a plurality of screws 22 which pass through the former and into threaded engagement with the latter. Arranged between the members I! and I9 is a block 23 having a plurality of shouldered bores 24 therein within which are slidably mounted a plurality of pistons or vanes 25.

The block 23 is machined so as to have parallel faces thereon which engage correspondingly machined faces on the members H and I8. Thus, when the block 23 is placed between the members l1 and i9, and the latter are secured together by the screws 22, the said members are exactly and positively spaced apart.

Disposed around the block 23 is a cylinder block 26 which has parallel faces thereon which exactly and slidably fit between the faces of the members i! and IS. The block 26 is provided with an eccentric bore 28, as shown in Figure 2, and is, likewise, provided with the bores 29 on either side thereof adjacent the ports 38 and 3| in the body I0.

Referring to Figure 3, it will be noted that the ports 29 are drilled passages which pass through the cylinder block thus communicating with the bore 28. The cylinder block is also provided with the reduced diameter bores 32, the function of which is to provide for a more or less gradual communication from the space between adjacent vanes and either the inlet or the outlet port of the body ID.

The cylinder block 25 is retained against angular movement within the body l by a pair of threaded locating pins 2'! which are threaded into the body In and engage apertures in the block 26. The block 26 is also engaged by machined shoulders on the body 18 and the member I3 50 that it is firmly and accurately retained in positon axially of the pump casing.

Referring to Figure 2, the rotor preferably rotates in a counter-clockwise direction thus transferring fluid from the inlet port 30 to the discharge or outlet port 3|. In order to accommodate the fluid which leaks from the pumping zone into the body 10,.the bores 33 are provided in the block 26 which communicate between the inlet port 30 and the interior of the body Ill. The suction created within the inlet port thus draws the fluid from the casing [8 into the said inlet" port. It will be understood that other means could be provided for draining the casing l8.

Referring to the vanes 25, these will be seen in Figure 2 to comprise substantially cylindrical, shouldered or stepped members adapted to fit within the shouldered bores 24. The vanes terminate at their upper ends in a double beveled peaked portion as at 34 so that a line contact exists between the said vane and the bore 28 of the block 26, and at their opposite ends in a cylindrical projection of smaller diameter than the shouldered portion thereof which is slidably received in the relatively reduced portion of the bores 24. Abore 35 connects between one side of the peaked portion 34 and the lowermost area 36 of the cylindrical projection of the vane, while a bore 3'! connects from the other side of the said peaked portion to the shouldered or stepped area 38 of the vane. The

areas

35 and 38 are so proportioned as to be equal and, therefore, each equal to one-half of the proejcted area of the end of the vane.

Referring to Figure 4, it will be seen that the diameter of the shoulder portion of the vanes 25 is greater than the distance between the members I1 and [9. The vane is provided with flats 39 on either side thereof which engage the facing surfaces of the members I1 and I9 and thereby retain the said vane against rotation while simultaneously providing a seal against leakage from one side of the vane to the other. It will be apparent that the flats 38 are effective to guide the vane only during the starting period of the rotor. After the vanes are in engagement with the cylinder bore 28, the engagement of the peak 34 with the bore 28 is effective to maintain the vanes against rotation.

Referring to Figure 5, the action of the balancing areas of the vane 25 is illustrated. In this figure it is assumed that the left side of the vane is in a pressure zone while the right side thereof is in a suction zone. The thrust on the left side of the vane is indicated by the solid arrows while the pressure on the suction side is indicated by the dotted arrows. The pressure from the pressure side is communicated through the bore 35 to the lower area 36 of the cylindrical projection which, being equal to the projected area of the upper end of the vane to the left of the peak 34, balances off the thrust therefrom. Likewise, any pressure standing on the right side of the end of the vane will be communicated through the bore 31 to the stepped area 38. The area 38 being effectively equal to the area of the right side of the end of the vane, any thrust on the vane due to suction pressure is completely balanced out. It will be apparent that the vanes are in a continuous state of full hydraulic balance axially. The thrust of the vanes against the block 26 will, therefore, be equal to the centrifugal force created by the rotation of the rotor. This centrifugal force, while sufficient to maintain the vanes in contact with the cylinder wall, is not sufficient to promote undue wear or scoring between the vanes and the cylinder bore.

The side thrust on the vanes due to the fact that pressure stands on one side thereof is carried by the cylindrical surface of the vane and the bore in which it reciprocates. It will be apparent that the method of this invention of providing cylindrical vanes is of distinct advantage as regard this side thrust. Theside thrust which is developed on the vanes is distributed over a substantially greater area than would be true if the vanes were flat. The unit compressive stress developed in the vane and the bore over the bearing area is thus substantially less than that ordinarily encountered in vane pumps. This reduces wear and promotes the free reciprocation of the vane within the bore. Also the machining of cylindrical bores and cylindrical vanes to any degree of fit is much more readily accomplished than in the case of fiat vanes and slots.

While the block 26 isshown in Figure I to be retained between shoulders on the body In and the cover plate [3 with sealing members indicated at 40 disposed therebetween, it will be apparent that other methods of supporting and sealing the block 26 are equally effective. Also, it will be noted that the block 26 maybe rotated through by removing the pins 2'!v so that, with the same direction of rotation, the pump will deliver pressure fluid from the port 30. instead of the port 3|.

Referring to Figure 6, an arrangement is shown whereby the pump may be made variable delivery. This is accomplished by arranging' the block 26 within the casing [0 in such a manner that the eccentricity of the cylinder bore 28 relaassassin 52 time to: the rotor [:1 may: be varied: Suitablecontroli means such as the; rods: til and are; provided whichextend throughapertures in the casing I for shifting -the;block: 26: The-rods: 41- and 32" may be attached to: anywsuitable manual orautomatic control means so thatthe; delivery; of the pump may be -selectively -varied int-response: to any givenstimulus.

In order to=providefluid comm-unication1between the bore 28 a-ndthe ports 1 3G and: 31" in: the pumpcasing, there. are provided the flatv portions 43=and 44i within the said casing WhiChrBII- gage the flat portions 45 and 56 onthe block 2-6; The flats4'3--to-46,' inclusive, are somachined that the block 28- exactly and: slidablyfits: bee tween-the-flats on the casing I0 thus-inhibitingleakage therebetween.

Thebl'ock 26-is provided with the bores ZB and 32 as in the case of the block 26 in Figure 2. It will beapparent that theblock 26 may be moved by therods'M and-' l-z froma position of full delivery in one direction, through neutral into a position of full d'elivery'i-n 'theopposite direction.

Referringito Figure 7-,pthel mannerinfwhichg the block 26 is retained within thezcasing' I fliisishown-l The casing ill is provided with, a shoulder d! which slidably engages the block 26 on one side. Theother side of the block 2-6 is engaged by a surface '48 onthe-member I it, the latter having a second-shoulder la-thereonwhich abuts a second shoulder 50 in the casing- Ill; The engagement of the shoulders 4-9-and- 5B-opposes the shoulders 4'1 and (98 so that the block 26' exactly and slidably fitstherebetween;

Also shown in Figures- 6*: and 7* is a modified vane structure'whereinthe flats on either side of the" vane areeliminated and the orientation of thevane is-secured by'means'of a pin- 5lwl1ich is setin a drilled holein thebottom of" the bore 24 and eccentnically'located-with, respect to said bore and extends into a hole 52 in the vane 25. The pin- 5| angularly lccates the vane 25 sothat fit Whenthe lattermoves outwardly due to centrifugal force the peaked portion 34 engages the cylinder bore Z'B-i'napmpermanner.

A plan view of the vane is shown in Figure 8 and indicates the eccentric location of the pin 5| and the relationship of the vane 25 with the rotor members I7 and l 9.

It will be apparent that various modifications may be made in the arrangement and construction of this device without in any Way departing from the spirit of this invention.

Accordingly, it will be understood that We wish to comprehend such modifications and substitution of equivalents as may be considered to come within the scope of the appended claims and the invention.

Having thus fully described our invention, what We claim as new and desire to secure by Letters Patent, is:

1. In a vane pump, a cylinder block having a bore therein, inlet and outlet means for said bore, a rotor rotatable within said bore, flanges on said rotor adapted continuously and slidably to engage said cylinder block on either side thereof, a plurality of shouldered bores in said rotor, a plurality of vanes having inwardly facing shoulders slidably mounted in said bores, said vanes having transversely beveled outer ends thereon, means comprising flats on opposite sides of said vanes in engagement with said flanges for retaining said vanes against rotation relative to said rotor each vane including, channel means hydraulically connecting one side of said beveled end 6 portion withtheishouldenofs said vane andzother channel means hydraulically.connecting the; opposite side" ofz said". beveled: endportion, with r the opposite endi-of'said vane.

2': As: an article. of manufacture, a, vane forfluid:v operable pumps; or motors: comprising asubstantially: cylindrical member having a done ble bevelfonx one endlthereof acyIindricaI'YprO- jecti'on: onthe otherendthereof' of: smaller diameter thantheibodyl portion ofsaid member, said cylindrical? proj ection definin with the: body-portion of' sai'dmember a shoulder facing toward: the cylindrical projection, and: channel; means bydraulically: connecting one side. of said beveled portion with the shoulder and: the other side of said-1 beveled portion: with the end of-' said projection; the end. of said projection and said shoulder having substantially: equal areas.-

3; Asan article of manufacture; a vane for. fluid operabl'epumps ormotors comprising, a

cylindrical-member having at step thereonfacing toward one endf of said member andformed' with a double bevelon: the opposite end thereof, at leastone fl'at portion on said opposite end at right: angles to said beveled portion, and'c-liannels extending through said memberand connecting one side of said: bevel with the step on said member and the other side-0t said bevel with the first-named end of saidmember, said step and said first-named end having" substantially equalareas;

4i. In a rotaryvane-type pump; a cylinder having' inlet and outlet ports therein; arotor rotatable Within said cylinder and formed with a pluralityof cylindrical radially disposed vanereceiving chambers, each of" the vane-receiving chambers ofsaidrotor comprisin an-outerbore and a relatively reduced inner bore providing-an inward continuation of the outer bore; a plurality of shouldered vanes slidably carried with-r in the chambers of said, rotor in close-fitting relation to the; Walls of said bores," each of said vanes being" formed with an inner cylindrical end" portion extending within. the, inner bore. of said chamber. and terminating, in, a, flat, pressure-responsive area, an intermediate diametrically enlarged cylindrical portion slidably positioned Within the outer bore of said chamber and defining a pair of relatively opposed pressure-responsive areas, and a cylindrical outer end portion terminating in a pair of angularly related pressure-responsive areas, the angularly related areas on the outer ends of said vanes merging to form a peak on said vanes for wiping engagement with said cylinder, a first channel in each of said vanes extending through the intermediate cylindrical portion thereof to establish communication between one of the said pair of angularly related areas disposed at the outer end of said vane and the inner area of the said pair of opposed pressure-responsive areas defined by the intermediate cylindrical portion of said vane, and a second channel extending through each of said vanes and estab-- lishing communication between the other of said pair of angularly related areas on the outer end of the vane and the flat pressure-responsive area on the inner cylindrical portion of the vane, the various pressure-responsive areas of each vane being sized to provide for the equalization of fiuid pressures acting thereon whereby to maintain said vanes in a state of pressure equilibrium at all times during the operation of said pump.

- 5. In a rotary vane-type pump; a rotor formed with a plurality of radially disposed stepped cylindrical vane-receiving chambers formed with inner and outer bores of different diameters; and a plurality of vanes freely reciprocable in said chambers and each comprising a body of substantially circular transverse crosssectional configuration formed intermediate its ends with a diametrically enlarged cylindrical portion disposed in wipin engagement with the walls of the outer bore of its chamber and defining on said body a pair of oppositely disposed fluid pressure-responsive faces, said body terminating at one end in a third pressure-responsive face and at its opposite end in a second pair of angularly related pressure-responsive faces, a first channel in said body extending from a point adjacent to one of said second pair of angularly related faces to the third pressure-responsive face, and a second channel in said body extending through the diametrically enlarged portion thereof on the side adjacent the other of said second pair of angularly related faces, the various pressure-responsive faces of said body being arranged to maintain said vanes in a state of pressure equilibrium when said rotor and vanes are operatively positioned in a pump.

6. In a vane pump, a cylinder having inlet and outlet means, a rotor rotatable within said cylinder, a plurality of substantially radial shouldered bores in said rotor, a plurality of vanes slidably mounted in said shouldered bores and each having a shoulder formed with a surface facing toward the center of said rotor, said vanes having beveled outer ends thereon, means associated With said vanes for retaining the same against rotation relative to said rotor so that said beveled end portion is retained substantially parallel to the axis of said cylinder, and channel means in each vane hydraulically connect ing one side of the beveled end portion thereof with the surface of the shoulder facing the center of said rotor and the other side of said beveled portion with the opposite end of said vane.

7. In a vane pump, a cylinder havin a bore therein and inlet and outlet means for said bore, a rotor rotatably supported within said cylinder, a pair of flanges attached to opposite sides of said rotor so as slidably to engage said cylinder block on either side thereof, a, plurality of substantially radial shouldered bores in said rotor, said bores having a diameter slightly greater than the transverse distance between said flanges, a plurality of substantially cylindrical shouldered vanes slidable in said bores and having flats formed on the opposite sides thereof so a to fit exactly and slidably between said flanges, the shoulder on said vanes facing inwardly, said vanes having transversely beveled ends thereon, and channel means for each vane hydraulically connecting the opposite sides of said beveled end portions with the opposite end of said vane and with the said shoulder thereof.

'NORMAN F. MACMILLIN. HOWARD M. PURCELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 983,754 Nichols Feb. 7, 1911 1,603,437 Wingquist Oct. 19, 1926 1,805,063 Wrona May 12, 1931 1,807,392 Davis May 26, 1931 1,819,867 Carlton Aug. 18, 1931 2,137,708 Wilson et a1. Nov. 22, 1938 2,149,337 Deming Mar. 7, 1939 2,159,941 Guinness May 23, 1939 2,335,284 Kendrick Nov. 30, 1943 2,354,076 Tucker et a1 July 18, 1944 2,356,916 Brewster Aug. 29, 1944 FOREIGN PATENTS Number Country Date 132,994 Switzerland July 16, 1929 166,871 Great Britain Jan. 5, 1922 524,897 France May 23, 1921 722,961 France Jan. 8, 1932