US2685256A - Rotary pump, motor, and the like - Google Patents

Description

Aug- 3, l954 M. w. HUMPHREYS 2,685,256

ROTARY PUMP, MoToR, AND THE LIKE Filed Deo. 5, 1951A 2 Sheets-Sheet l INVENTQR. l MAH/0N (v. UMP/w06 37 Y? li @TTG/ENE Y.

Aug.'3, 1954 M: W. H UMPHREYS ROTARY PUMP MOTOR, AND THE LIKE Filed Dec. 5, 1951 INVNTOR MAR/cw W. HUM/UHR@ v5 ATTORNEY@ 2 Sheets-Sheet Patented Aug. 3, 1954 UNITED STATES ATENT OFFICE ROTARY PUMP, MOTOR, AND THE LIKE Marion W. Humphreys, Euclid, Ohio Application December 5, 1951, Serial No. 259,934

(Cl. S-129) while having a general or superficial resemblance to a guided-vane type pump and motor, has a considerably higher mechanical and volumetric efficiency, the latter having low resistance to leakage because the vane tips can only have a line contact with the housing bore and being apt to overheat and subject to excessive wear at high speeds as a result of the centrifugal forces on the vanes, and thus high pressure contact with the housing bore with resultant high friction losses.

Another object of this invention is to provide a device of the character indicated which may be operated at high speed and under high pressure without danger of overheating.

Another object of this invention is to provide a device of the character indicated wherein there is continuous surface contact as distinguished from line contact as aforesaid between the moving displacement-cavity defining parts thereof to offer not only a high resistance to leakage but further to result in a low pressure centrifugal contact between said parts even at high speed operation of the device.

Another object of this invention is to provide a device of the character indicated in which the diplacement can be varied and the direction of operation reversed merely by manipulation of the relative positions of the displacement-cavity forming parts thereof.

Another object of this invention is to provide a device of the character indicated wherein the relative sliding of the tips of vane-like members and the outer and inner walls of the chamber in which said members operate is reduced to a minimum.

Another object of this invention is to provide a device of the character indicated having a novel actuating mechanism for causing relative movement of the displacement-cavity defining parts thereof.

Another object of this invention is to provide a device of the character indicated having a novel form of displacement-cavity dening part for economy of manufacture, said part being hereinafter referred to as a pressure block.

Other objects and advantages will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail one illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a diametrical cross-section View of one embodiment of the invention taken substantially along the plane indicated by line I-i, y

Fig. 2;

Fig. 2 is a transverse cross-section view taken substantially along the plane indicated by line 2 2, Fig. l

Fig. 3 is a fragmentary cross-section view taken substantially along the plane indicated by line 3-3, Fig. 1; and

Fig. 4 is a perspective view of one of the pressure blocks employed in the device constituting the present invention.

Referring now in greater detail to the annexed drawings, the device therein illustrated comprises a housing I including the parts 2 and 3 which are bolted or otherwise secured together. Said housing part 2 is formed with fluid inlet and outlet ports or passages 4, 4 leading into a recess 5 formed in said housing part. Axially slidable in such recess 5 is a plate 6 having a keyl extending therefrom into a groove 8 in the bottom of such recess, said key I dividing the recess into two separate chambers 9 and I0 to which the inlet and outlet passages 5I, 4 respectively lead. A suitable packing ring I I around said plate forms a seal to prevent leakage of fluid from such chambers 9 and Iii into the portion of said housing I between said plate 6 and housing part 3. Said plate 6 is resiliently pressed in a direction towardthe opposed plate I2 as by means of a series of coil springs I3 or the like which are operatively interposed between said housing part 2 and said plate 6.

The aforesaid oposed plate I2 is journalled in said housing part 3 as by means of suitable antifriction bearings I4, I4 and has a shaft portion I5 extending axially therefrom and through said housing part 3 and constituting the input or output shaft according to whether the device is operated as a pump or as a motor.

Disposed between said plates 6 and I2 in sliding engagement therewith is a floating cylindrical Said plate t is formed with a pair of arcuate 'l slots I9 and 28 therethrough which communicate the respective chambers 9 and IIl with such annular chamber I8.

Radially traversing such'annular chamber i8 and maintaining the cylindrical Vwalls thereof concentric are a series of segmental pressure blocks 2l which are of thickness equal to the thickness of said ring IE and said cylindrical member il so as to have close sliding fits at their opposite ends with said plates t and I2. Said pressure blocks 2l are each formed with an outer cylindrical surface 22 of substantially the same diameter'as the inside diameter of said ring Il and an inner cylindrical surface 23 of substantially the same diameter as the outside diameter of said cylindrical member I. The end of each pressure block 2l which faces said plate E2 is formed with a radial slot 24 defined by parallel fiat surfaces 23 in which one of a corresponding series of intermediate members 25 is radially slidable to form a Scotch yoke type connection for circumferential driving of said blocks and radial sliding of said members 25 in said blocks, said intermediate members 25 being oscillatably carried on axially projecting crank pins 26 which are uniformly spaced around the central axis 2l of said plate I2 and shaft portion it. Said intermediate members 25 are preferably formed with one or more passages therethrough, as best shown in Fig. 2, which communicate the portions of the slots 2i radially outward and inward thereoi and furthermore other passages are provided through said intermediate members 23 to conduct fluid, usually oil or other iiuid having lubricating qualities, to the surfaces of the respective crank pins 2S so as to lubricate said intermediate members 25s for oscillation on said crank pins 26.

`Said blocks 2l have a combined circumferential extent less than 360 so that they may partakeV of relative circumferential movement in chamber I8 and further the depth of slots 24 is greater'than one-half the Vthickness of said blocks to reduceeccentric loading while yet provide a section 28 of substantial thickness for strength and high vresistanceto leakage and still further the width of slots 24 is such that relatively wide surfaces remain for high resistance to leakage between said blocks and said ring Il and member I6.

The annular chamber forming parts, viz. ring Il and cylindrical member IS, are supported for transverse adjustment between plates E and I2 so as to vary the eccentricity between the axis 28 of vsuch chamber i8 and the axis 2l of rotation of said plate I2.

It is to be noted that said ring il is supported for free rotation as by means of an anti-friction bearing 30 and it is to be understood that suin- K cient play is provided in said bearing` 3b so as not to effect any binding between said ring Il and pressure blocks 2I.

Projecting radially from the bearing race member 3l, preferably from diametrically opposite sides, are shafts 32 and 33, one of which (32) is slide-guided in an opening in housing part 2, and

the other of which (33) is threaded into an adjusting nut 34 which is rotatable in housing part 2 and as evident, the rotation of said nut 34 will transversely shift said ring I'I and cylindrical member I6 to a desired eccentric position with respect to plate I2, said nut being held against transverse movement as by means of a pin 35 which engages in a peripheral groove in said nut. The periphery of said nut 34 may be serrated or otherwise irregularly formed for engagement by a spring detent 36 which is operative to hold said nut against inadvertent rotation during the operation of the device.

As shown in the drawings, the plane of adjustmentor annular chamber I8 relative to the axis 2l of plate VI2 is parallel to said rib or key 1 and parallel to the opposed ends of the arcuate slots I9 and 2Q in plate 5.

As best shown in Fig. 2, displacement cavities 3l are defined between successive pressure blocks 2I, the volumetric capacity of such cavities being determined by the circumferential space between successive blocks, and, of course, 'the displacement thereof will vary in accordance with the amount of eccentricity between the axis 29 of annular chamber I3 and the axis 21 of plate I2.

Considering that plate I2 and pins 28 thereon are rotating in a clockwise direction as viewed in Fig. 2, the cavities y31 to the right of a vertical center plane, while in communication with the arcuate slot 2t progressively increase in size whereby fluid will be drawn Ythereinto through one passage 4, chamber Ill, and slot 20 when the device is operated asia pump and the cavities 3l to the left of a vertical center plane progressively decrease in size while in communication with the other` arcuate slot I9 whereby the fluid in such cavities is discharged therefrom through such arcuate slot I9, chamber 9, and the-other passage il when the device is operated as a pump. Similarly, when the device is operated as a motor, fluid under pressure willA enter theenlarging cavities {I'Iv to driveplate I2 and the spent fluid will be discharged fromthe decreasing cavities S'I.

Now, as evidentif the adjusting assembly is operated to cause the axis 29 of annular chamber I8 to coincide with the axis 2l of said plate I2, the cavities 3! will -remain of xed sizeduring the circumferential movementl of said pressure blocks 2l through such annular chamber and Vthereforethedevice will have a zero Adisplacement. Y If the adjusting mechanism is shifted to position the axis 29 of the annular chamber I8 above the axisf'2`I of said plate I2, rotation of pla-te I2 in a clockwiseV direction will reverse the direction of iiowY ofthe' fluid through-arcuate slots I9 and 2B, chambers 9 and `it land passages 4, that the slot IS- will become the inlet and the other slot 22 will become the-outlet.

AS aforesaid, the slot 24 formed inv each pressure block 2Iv ispreferably of a depth'more than one-half the thickness Lof said block so as to reduce eccentric forces and yet-provide a.v relatively thick wall 28. As shown, the outer'and inner cylindrical surfaces 22 and 23of'"said blocks 2I which-have sliding lit with ring I1 and with cylindricalmember I6 are of substantial circumferential extent to provide a Wide surface contact as compared with the line contact in the ordinary guided-vane type devices. In this way the present device has ahigh resistance to leakage or'fbypass between successive cavities 31. The spaces between Athe opposed ends .of lthe arcuate .slots I9. and. 20,. are preferably at--least equal to'the maximum circumferential space between said blocks 2l so as to avoid intercommunication between the inlet and outlet of the device under all conditions of transverse adjustment of the displacement assembly of the device.

It is to be noted that when said pressure blocks 2| move circumferentially through the annular chamber E8 and are urged outwardly by centrifugal force, the engagement between the outer cylindrical surfaces 22 thereof and the inner cylindrical surface of ring I'I will cause rotation of the latter in unison therewith and therefore the only sliding between said pressure blocks 2i and said ring I7 is the negligible amount owing to the relative circumferential movement of said pressure blocks when moved toward and away from each other to increase and decrease the volumetric capacities of the cavities ii'I defined between the successive blocks. Thus, even though the device is operated at extremely high speeds, the movable parts thereof are not subjected to wear and the friction losses will be very small, enabling operation of the device Without danger of overheating.

In order to assure that high pressure operation of the device will not result in undue clamping of ring Il, pressure blocks 2i, and cylindrical member I8 between plates 6 and I2, the effective areas on opposite sides of said plate e which are exposed to the fluid are substantially equal or at least partially balanced so that under all conditions of operation the main force tending to clamp the aforesaid parts between said plates 6 and I2 is that exerted by springs I3 since the effect of the pressure of the fluid on plate 6 is more or less balanced.

The key 'I aforesaid which is mounted in plate 6 is preferably provided with a groove 38 or like passage which prevents trapping of fluid in the chamber between said key 7 and groove 8.

While but one form of the invention has been illustrated herein, it is to be understood that where rotation of an eccentric member is referred to, such rotation'may be a relative rotation and therefore housing I or other member may be rotated while said plate I2 is held against rotation. Similarly, while the annular chamber IS may be transversely adjusted relative to the axis 2l of said plate I2, it will be apparent to those skilled in the art that the annular chamber forming elements may be transversely xed in housing I and the plate I 2 may be mounted for such transverse adjustment to vary the eccentricity between axes 27 and 29.

Furthermore, the transverse adjustment for variable displacement may be automatically effected in response to fluid pressure as by providing a spring bearing on one shaft 32 or 33 and by leading iiuid under pressure delivered by or to the device so as to act on the end of the other shaft formed as a piston. Thus, if the pressure increases, the annular chamber I8 is shifted to reduce the displacement, and, conversely, if the pressure decreases, the shifting is such as to increase the displacement.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a device of the character described, the combination of a housing provided with fluid inlet and outlet passages, concentric outer and inner cylindrical members of equal axial extent having end faces in parallel planes perpendicuiar to their common central axis, said kmembers being disposed to rotate relative to said housing about such axis, a pair of parallel plates slidably engaging the respective end faces. of said cylindrical members to define therewith an annular chamber, one plate being non-rotatable in said housing and being formed with fluid passages therethrough communicating the respective fluid inlet and outlet passages with suoli annular chamber, the other plate being journalled in said housing for rotation about an axis eccentric to the axis of such annular chamber and having crank pins extending therefrom into such chamber, said pins being circularly arranged about the axis of rotation of other plate, and at least two segmental blocks circum ferentially movable in such chamber and rie-fio` ing therebetween a cavity which varies in size according to the circumferential space between said blocks and having concentric cylindrical surfaces in sliding engagement with the cylin* drical Walls of such chamber and end faces in similar sliding engagement with the respective end `walls of the chamber as deiined by said plates, said blocks being formed with radial slots into which said crank pins respectively extend for circumferential driving and radial sliding engagement with said blocks for causing relative circumferential movement of said blocks to respectively increase and decrease the size of such cavity while the cavity communicates with the passages through said one plate.

2. The device of claim 1 wherein anti-friction bearing means journal said outer cylindrical member for rotation by said blocks.

3. The device of claim l wherein said housing is formed with a circular recess to which such inlet and outlet passages lead, said one plate is tted into such recess, and an interfltting rib and groove are provided diametrically across said one plate and such recess for rendering said one plate non-rotatable in said housing and for sub-dividing such recess into separate chambers which respectively communicate with the 'passages through said one plate and the inlet and outlet passages in said housing.

4. The device of claim 3 wherein said one plate is axially slidable in such recess and spring means are provided to press said one plate toward said other plate to thereby resiliently en gage said cylindrical members and blocks between said plates.

5. The device of claim 4 wherein said one plate has substantially equal areas on its face which engages said cylindrical members and blocks and its opposite face exposed to fluid in the respective passages so that the principal axial force exerted on said one plate during operation of said device is that exerted by said spring means.

References Cited in the le of this patent Great Britain 1934

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