Radial vane pump

March 13, 1951

N. F. MacMILLIN ET AL

RADIAL VANE PUMP

2,545,238

Filed Aug. 7, 1944

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INVENTORS

Norman F, Mac Millin, ^Y Howard M Purcell,

ATTORNEYS

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March 13, 1951

N. R MacMILLIN ET AL

RADIAL VANE PUMP

2,545,238

<img file="US2545238A_D0002.tif" />

ATTORNEYS

March 13, 1951

N. F. MacMILLIN ET AL

RADIAL VANE PUMP

2,545,238

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INVENTORS

Norman F· MacMilur, by Howard M. Purcell,

ATTORNEYS

Patented Mar. 13, 1951

2,545,238

UNITED STATES PATENT OFFICE

2,545,238

RADIAL VANE TUMP

Norman F. MacMillin and Howard 'M. Purcell, Mount Gilead, Ohio, assignors to H-P-M Development Corporation, Wilmington, Del., a corporation of Delaware

Application August 7,194.4, SeriatNo. 548,334

Claims. (Cl. 103—136)

This in vention. relatestofluid operable apparatus and, particularly, to fluid operable .pumps or motors. More particularly still this invention relates to vane type pumps or motors.

It is a primary object of .the present invention 5 to provide a vane pump or motor in which the wearing action which normally takes place between the ends of the. said vanes and a cylinder within which they are .movable is substantially eliminated. 10

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 15 machinery.

-It is .another object to provide a vane pump or motor structure in which the bearing load of the vanes .in the rotor is reduced thereby to inhibit sticking of the vanes and excessive wear. 20

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 fol- 25 ..lowing description taken , in connection with the accompanying drawings, in which:

Figure 1 is a longitudinal -section through a pump or motor constructed according to this invention; 30

Figure 2 is a transverse - section through the pump or motor and is indicated by the line 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 35 cylinder block;

Figure 4 is a plan view taken over one of the vanes of the pump or motor showing its relationship to the guidewalls on either side thereof;

Figure 5 is a view of the piston-vane illustrat- 40 ing the action of the balancing surfaces-thereof;

Figure 6 is a transverse view through a modified structure showing a reversible variable discharge type of pump constructed according to this invention; 45

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

Figure 8 is a plan view over the piston vane in ⁵⁰Figure 7 showing its relationship to the guidewalls on either side thereof.

General arrangement

A pump or motor constructed according to this 55 invention comprises, generally, a casing within which is rotatably mounted a .rotor having bores therein for receiving reciprocating vane members. The vane members-are-adapted to ride on the-inner-Surface .of a-cylindrieally bored:mem- ⁶⁰ ber 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 areas hydraulically connected 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 other side thereof is under suction pressure, a first balancing area is hydraulically connected to the pressure side to balance off the thrust -therefrom while a 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 device is 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 members are preferably cylindrical, -thus simplifying the machining thereof and also /provide for a greater area of contact between the said vane members 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 ί 0 which is hollow to receive a rotor I 1 and which is also bored to receive an antifriction bearing 12 within which the said rotor is journalled. The body . 10 is engaged by a cover plate or closure member 13 which is secured in place by any suitable means 'such as the screws 14. The member 13 may be flanged to provide a mounting base for the pump and, to this end, may comprise the countersunk screw holes 15. Similarly to the body 10, the member IS is bored to receive an antifriction bearing 16 which, together with the bearing 12 serves as a support for the rotor it. The rotor I I comprises a first member 17 which has integral therewith the trunnion portion 18 adapted to be received within the bearing 12 and, a second member 19 which has integral therewith the trunnion portion 20 adapted to be received within the bearing 16. The member 19 also comprises a shaft 21 which extends through an aperture in the member 13 so that the rotor 11 may be driven from any suitable source.

2,046,238

The rotor members 17 and 19 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 17 and ί 9 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 17 and 19. Thus, when the block 23 is placed between the members 17 and 19, 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 17 and 19. 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 30 and 31 in the body 10.

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 10.

The cylinder block 26 is retained against angular movement within the body (0 by a pair of threaded locating pins 27 which are threaded into the body 10 and engage apertures in the block 26. The block 26 is also engaged by machined shoulders on the body 10 and the member 13 so 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 31. 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 10. The suction created within the inlet port thus draws the fluid from the casing 10 into the said inlet port. It will be understood that other means could be provided for draining the casing 10.

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. A bore 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 37 connects from the other side of the said peaked portion to the shouldered or stepped area 38 of the vane. The areas 36 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 mem4 bers 17 and 19. The vane is provided with flats 39 on either side thereof which engage the facing surfaces of the members 17 and 19 and thereby retain the said vane against rotation while simul5 taneously providing a seal against leakage from one side of the vane to the other. It will be apparent that the flats 39 are effective to guide the vane only during the starting period of the rotor. After the vanes are in engagement with 10 the cylinder bore 28, the engagement of the peak 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 15 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 20 by the dotted arrows. The pressure from the pressure side is communicated through the bore 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 37 to the stepped area 38. The area 38 being effectively equal to the area of the right 30 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 35 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 scor⁴⁰ ing 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 ⁴⁵ apparent that the method of this invention of providing cylindrical vanes is of distinct advantage as regard this side thrust. The side thrust which is developed on the vanes is distributed over a substantially greater area than would be ⁵⁰ 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 flat vanes and .... slots.

^υ While the block 26 is shown in Figure I to be retained between shoulders on the body 10 and the cover plate ί 3 with sealing members indicated at 40 disposed therebetween, it will be apparent , that other methods of supporting and sealing the ^J block 26 are equally effective. Also, it will be noted that the block 26 may be rotated through 180° by removing the pins 27 so that, with the same direction of rotation, the pump will deliver pressure fluid from the port 30 instead of the ⁷⁰ port 31.

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 10 in such a manner that the eccentricity of the cylinder bore 28 rela2j54$288;

&amp;

tive·- to- the·- rotor h( may be? varied; Suitable control: means· such as the rods 4i and 42: are; provided which- extend/through· apertures in the· casing i 0 for shifting the, block 26; The rods 4t and-42: may be attached to any suitable· manual or automatic control means· so that the; delivery ofc the· pump-may be selectively varied in- response, to- any given stimulus; '

In order to- provide fluid communication, between the bore 28’and: the ports 30 and: in the pump casing-, there: are· provided the- flat· portions 43^:and'^;44';within the*said casing which·engage- the·- flat portions 45 and' 45’ on- the- block 25. The flats-43'· to-46, inclusive, are so-maehined that- the- block 26 exactly and- slidably- fits/ between-the-flats on the casing· 10-thus inhibiting leakage therebetween.

The block 26 is provided with the bores 29and 32 as in the case of the block 26 in Figure 2. It will-be apparent- that the-block 26 maybe moved by therods-41 and’42-from a position of full delivery in one direction through neutral into a position of full delivery in the-opposite direction.

Referring:to Figure 7, the.manner in which the block 26 is retained within the/casing-18; iS; shown. The casing, 1-0 is provided with a, shoulder 47 which slidably engages the block 26 on one side. The-other side of the block-26 is engaged by a surface 48 on the-member 18- the latter having a second shoulder-49 thereon which abuts a second shoulder 50-in-the-casing- 10; The engagement of the shoulders 49-and-50-opposes the shoulders 47 and* 48 so that the block 26 exactly and slidably fits- therebetween-.

Also shown- in- Figures- 6^;· and 7 is a modified vane structure wherein-the-fiats-on either-side of the- vane are- eliminated and’ the orientation of the-vane is-seeured- by meansof-a pin- 5! which is set-in a-drilled hole-in the bottom of the bore 24 and eccentrically located with, respect to said bore and extends into a hole 52 in the vane 25. The pin-51 angularly locates the vane 25 so that when- the latter moves outwardly due to- centrifugal force the-peaked-portion 34 engages the cylinder bore- 28-in a proper-manner.

A¹ plan-view-of the vane is· shown in Figure 8 and indicates the eccentric location of the pin 51 and the relationship of the vane 25 with the rotor members 17 and 19.

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.