US2808004A

US2808004A - Pumping mechanism

Info

Publication number: US2808004A
Application number: US272282A
Authority: US
Inventors: John D Durant; Kermit R Mcclelland
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-19
Filing date: 1952-02-19
Publication date: 1957-10-01
Anticipated expiration: 1974-10-01

Description

Oct 1 1957 J. D. DURANT ETYAL 2,808,004

PUMPING MECHANISM TTFNE V Oct. l, 1957 J. D. DURANT ETAL 2,808,004

PUMPING MECHANISM Filed Feb. 19, 1952 2 SheelLs-Sheerl 2 IN V EN TORS.

(54% @yf/wf fff/f/f/Mf nited States PatentO stracci PUMPING MECHANISM John D. Durant, Holly Hin,- ana Kermit n. Machined,

Daytona Beach, Fla.

Application February 19, 19.52, Serial No. 272,282

12 Claims. (Cl. 10S- 42) of the pump decreases as the delivery requirements decrease so that power of the engine or other prime mover used to drive the pump is not wasted in useless circulation of the liquid as is common in many pumps which simply by-pass the excess liquid. In addition to wasting horsepower in the unnecessary circulation ofliquid these by-pass type pumps also churn and heat up the liquid unduly, making necessary the use of expensive additives to the liquid to minimize the detrimental elects of the churning and heat generation. Also, it will be appreciatedy that pumps of the present type eliminate the costly by-pass valve which in the above mentioned by-pass type pump must be capable of handling the ilull volume `of the pump'and are very expensive compared to the cost of the pump.

It is an object of the present invention to provide an improved rotary vane type variable delivery pump, the pumping action of which automatically varies with the delivery requirements. f

It is also an object of the present invention to provide an improved pump of the above mentioned type which is simple in design, economical of manufacture and reliable and eicient intoperation.

It is a further object of the present invention to provide an improved pump of the above mentionedtype having novel and improved means for positioning the vanes .and providing a seal preventing the leakage of the liquid .beingpumped past the ends of the rotor.

Another object of the present invention is to provide :an improved pump of the above mentioned type including a movable segment defining a portion of the wall .of the pumping chamber and which is urged tow'ard'the position of maximum delivery by resilient means supplemented by hydraulic pressure supplied from the discharge side of the pump.

It is also an object of the present invention to provide a pump of the just mentioned type including means for automatically relieving the just mentioned hydraulic pressure supplementing the resilient means, when lthis hydraulic pressure reaches a predetermined maximum.

Other and more detailed objects of the present invention will be apparent from a consideration of the following specification, the appended claims and the accompanying drawings wherein:

Figure 1 is a sectional view showing a pump embodying the present invention and taken substantially along the line 1-1 of Figure 2;

Figure 2 is a sectional view of the pump illustrated in Figure l, taken substantially along the line 2 2 thereof;

Figure 3 is a sectional view of the structure illustrated in Figure l, taken substantially along the line 3-`-3 thereof; and,V v

2,838,0@4 ir-'Patented Oct.v l, 1957 ICC.

n Figure 4 is a broken sectional view similar to the Vulitper portion of Figure 3 and showing the position of the parts at z'e'ropdeliveryfrorn the pump.

Referring to the drawings, the pump generally comprises a central pump body 10, a front plate l2, a rear 'plate 14, a r'otor 16 disposed within the pump body 10 and carried on a shaft 18 journaled in the front and

rear plates

12 and 14, 'a plurality of vanes 20 carried Eby `the rotor`7`16, a block 22 movable to vary thel delivery "of the pm'p and'means generally indicated at 24 for automatically positioning the Yblock 22 to conform to the changes in the delivery requirements.

Considering the above mentioned elements in greater ldetail, the Vpump body 10 has an inlet opening 26 yand' an outlet opening'ZS and co-operates with the front and rear 'plates 12 andy 14, which are secured thereto by any suity `able'y means s'uch as

screws

30 and 3,2, to define a central vpumping chamber 34. VThis pumping chamber is cylin- "dri'c'al in shape and includes a pair of spaced parallel'side walls 36 and -38' formed on the front and

rear plates

12 and 14 respectively, and a cylindrical wall 40. As best illustratedin Figure l, the opposite end portions of the icylindricalwall' 40 are formed in the front and rear plates '112' and' 1'4 and the intermediate portion of this cylindrical wall 4'0 is'forme'd in the pump body'It). The inlet V26 communicates with the pumping chamber 34' througha pair of arcuately extending recessesq42, and the outlet 28 `s'iinil'a'rly communicates with the pumping Vchamber 34 'through -a pair of arcuately extending recesses 44. These 'recesses 42l and 44 are vformed in the intermediate portionv of the cylindrical wall 40 defined by the pump body V10, as best illustrated in Figurel. y `l The frontv and rear plates 12k and 1'4'hav'e `oppo'sitely Vextending bosses 46 and 48 in which are carried aligned bearings 50 and 52 respectively,fin which the shaft 18 is journaled for rotation aboutan axis 54 spaced from and KYparallel tothe axis 56 of the cylindrical wall 40. The

'rotor 16 is securedV tothe shaft 18rfor rotation therewith and disposed within the cylindrical pumping chamber 34.

Therotor 16 is cylindrical in shape, and of a diameter substantially smaller than that of the cylindrical wall 40.

The rotor 16`al`so has a plurality of equiangularly spaced radially extending slots 5S' in which the vanes 20 are mounted. Thevanes 20 are or a length, measuredalong the axis of the shaft 1S, slightly less than the distance between the end faces 36 and 38 of the 'pumping'chamber 34.'

As best illustrated in Figure 1, the vanes 20 are notched at theirl inner edges at the oppositeends thereof, asindicatedfa't 59, Yto receive guide rings'60 which bear against the end walls 36 and 38 of the pumping chamber. These guide yrings 60 serve as thrust rings'and position the vanes Y20 between and out of contact with the end walls 36 and 38. These guide rings 60 have an'external diameter adapted to closely t within the notches 59 when the vanes 20'are disposed with their radially outer'edges in contact with the cylindrical wall 40 of the pumpingchamber 34. Theopposite ends of the rotor 16 are undercut to provide an axiallyinwardly extending central recess 62 adapted to receive the guide rings 60y and permit the movement of'theseguide rings 60 transversely of the axis of the rotor 16 which accompanies operation of the pump. The guide ringsv60 also act as a seal preventing leakage of liquid vfrom the outlet side of the pump past the endy of lthe rotor 16 and tothe inlet side.

In thepreferred embodiment illustrated, the bearings 50 and 52 are lubricated by the liquid being pumped.

For this purpose a passage 64 is formed in the rear plate 14 with one end thereof ropening into the pumping chamber` `at any suitable place on the pressure side of the .pump vand lhaving its other end opening radiallyA through the bearing 52. The shaftrlS has an annular groove 66 aligned with the last mentioned end of the passage 64 and a radially extending passage 68 which connects the annular groove 66 with a centrally disposed axially extending passage 78 formed in the shaft 18. is lubricated from an annular groove 72 in the outer surface of the shaft 18 `which communicates with the central passage 70 by means of a radially extending passage 74.

Intermediate the bearings 50 and 52, the shaft 18 has another annular groove 76 in its outer surface which communicates with the central passage 70 by means of a radially extending passage 78. Referring to Figures 1 and 2, the rotor 16 is provided with a plurality of radially extending passages 80 individual to the vane receiving slots 58. These passages 80 connect the slots 58 with the annular groove 76 to supply liquid under pressure to the vane receiving slots 58 and hold the vanes in contact wlth the cylindrical wall 40 of the pumping chamber 34.

The pump body and the front and

rear plates

12 and 14 define a chamber 82 of rectangular cross section disposed at the upper side of the pump as' illustratedin the drawings, and extending at right angles to the axis of the pumping chamber 34.4 The movable block 22 is mounted within the chamber 82 and of a cross-sectional shape adapted to nt the chamber 82 for sliding movement longitudinally thereof. The lower surface of the block 22, indicated at 84, `is cylindrical and has a radius of curvature equal to that of the cylindrical wall 40 which is, of course, interrupted at the movable block 22 and the surface 84 at the inner end of the block 22 kconstitutes a portion of the Wall of the pumping chamber 34, The block 22 is movable between a rst position illustrated in Figures l, 2 and 3 corresponding to maximum volume delivery of the pump and in which the cylindrical surface 84closely approaches but is spaced slightly radially outwardly from the adjacent portions of the cylindrical wall 40, and a second position illustrated 1n Figure 4 and corresponding to zero volume delivery from the pump. Movement of the block 22 beyond these limits is prevented by a pin 86 extending through and supported in the front and

rear plates

12 and 14, and which extends through an enlarged opening 88 formed in the block 22. Since the pin 86 prevents movement of the block 22 beyond the position illustrated in Figures 1, 2 and 3, there will at all times be at least the small space illustrated in these figures between the surface 84 of the block 22 and the adjacent of the vanes 20.` This insures the exposure of the surface to liquid under a pressure substantially equal to the discharge pressure of the pump. Adjacent the outlet 28 the lower corner of the block 22 is relieved as indicated at 90 to also facilitate the exposure of the surface 84 of the block 22 to liquid under a pressure substantially equal to the discharge pressure of the pump.

The outer end of the chamber 82 is closed by a cover plate 92 secured in place by the screws 94. The block 22 has a recess 96 in its outer end. A coil spring 98 has one end received in the recess 96 and acting against the block 22 and its other end bearing against the cover plate 92. The spring 98 yieldably holds the block 22 in the position illustrated in Figures l, 2 and 3. The action of the spring 98 is supplemented by hydraulic pressure exerted on the outer end of the block 22 by liquid supplied to the chamber 82 through a passage 100 formed in the pump body 10 and extending from one of the recesses 44 at a point adjacent the outlet 28 upwardly, as viewed in the drawings to the upper end of the pump body 10., The cover 92 has a passage 102 connecting the passage 100 with a passage 104 opening into the chamber 82. The passage 104 also connects with another passage 106. The cover 92 also has a passage 108 connecting with a passage 110 formed in the pump body 10 and opening into one of the recesses 42 adjacent the inlet 26.` The cover 92 also carries valve means for controlling communication between the

passages

106 and 108 The bearing 50 `reduction in the delivery of the pump.

ments from the pump are zero.

and adapted to automatically establish such communication when the pressure within the passage 106 exceeds a predetermined value. In the embodiment illustrated this valve means comprises a spherical valve element 112 yieldably urged to the seated position illustrated in Figures l, 2 and 3, in which it closes one end of the passage 106, by a coil spring 114. To provide for the desired preloading of the spring 114, and adjustment thereof as desired, a set screw 116 is threadedly mounted in the` cover 92 and engages the outer end of the spring 114. The set screw 116 is locked in adjusted position by a nut 118 threaded on the screw 116 and abutting the cover 92.

The proportions of the

passages

100, 102, 104, 106, 108 and 110 are such that upon the pressure in the passage 106, and hence in the chamber 82 to which it is directly connected by the passage 104, reaching a value sutlicient to produce an unseating of the ball valve 112, a drop in the pressure within the chamber 82 results. In the construction illustrated the cross-sectional area of the passages and 102 are substantially less than those of the

passages

104, 106, 108 and 110. The strength of the spring 98 is such that upon an unseating of the ball 112 and the accompanying drop of pressure in the chamber 82, the pressure exerted on the inner end of the block 22 at the cylindrical surface 84 thereof exceeds the pressure exerted on the block 22 by the reduced hydraulic pressure in the chamber 82 and produces a movement of the block 22 upwardly as viewed in the drawings and producing a further compression of the spring 98. This movement of the block upwardly permits a flow of liquid from the pressure side of the pump, at which the outlet 28 is located, to the intake side of the pump between the outer edges of the vanes 28 and the cylindrical surface 84 at the inner end of the block 22. The volume of this flow is dependent upon the degree of movement of the block 22 and rapidly reduces the delivery of the pump.

In operating the pump, the set screw 116 is adjusted to produce a preloading of the spring 114 sucient to hold the ball. valve 112 seated until a predetermined desired discharge pressure is produced at the outlet 28. When this pressure is reached the hydraulic pressure with in the passage 106 overcomes the action of the spring 114 and unseats the ball 112. This results in an upward movement of the block 22 producing an accompanying ln some pump applications there are periods when the delivery require- Upon use of the above described pump in such applications the block 22 will move upwardly to the position illustrated in Figure 4 and the ball valve 112 will move to the unseated position there illustrated. During these periods no liquid is drawn in through the inlet 26 nor discharged through the outlet 28. A part of the liquid which is carried from the intake side of the pump to the pressure side of thc pump between the vanes 20 circulates through the

passages

100, 102, 104, 196, 108 and 110 and maintains the ball 112 in the unseated position there illustrated and the remaining part of this liquid flows from the pressure side of the pump to the intake side of the pump between the rotor 16 and the cylindrical surface 84 at the inner end of the block 22.` It will thus be appreciated that during this time there is very little liquid circulated and very little work done and accordingly, very little power is required for driving the pump. Upon an increase in the delivery required from the pump the block 22 returns toward the full capacity position illustrated in Figures l, 2 and 3 as required to provide the volume of liquid lo be delivered.

It will be appreciated, of course, that for any given application the pump is so designed that when running at the minimum speedvat which it will be operated, it will have a volume delivery equal to the maximum delivery desired.

It will also be appreciated that this pump design may vanciano/i Y be. .usedzin .connection with extremelyhigh pressure ranges ,pressurewhich the liquid within the pump exerts on the cylindrical surface 84` of the movable blocky 22. In the preferred embodiment illustrated the construction of the pump is such that the cylindrical surface 84 at the inner end-of the block 22 is approximately equal to a segment of thenrotor 16 defined by three adjacent vanes 20.

While'only one specific embodiment of the invention has beenY illustrated and described in detail, it will be readily appreciated bythose skilled in the vart that numerous modifications and changes may be made without departing from'the spiritrof the invention.

Whatzis claimed is:

1. Av variable delivery pump mechanism comprising means defining a'pumping chamber, a rotor -mounted for rotation insaid pumping chamber, a plurality of vanes carried by` said rotor, said means including a member disposable in one position`- correspondingto maximum volumedelivery of said pump and movable in one direction from said position to reduce the delivery of said pump, said member being exposed to a pressure within said chamberV related to the discharge pressure of said y pump `and urging said member in said one direction, resilmeans,V andpmeans for automatically relieving said'hydrau'licfpressure -supplementingsaid resilient means when theA discharge pressure of said pump reaches a predetersure side of said pump mechanism' to the low pressure ,side thereof, said member being disposable in one position corresponding to maximum volume delivery of Vsaid pump and movable in one direction from said position to'reduce. the delivery of said pump andV increase the space'between said portion of said member and said rotor,

said member being exposed to a pressure within said chamber related to the discharge pressure ofl said pump and urging said member in said one direction, resilient means urging said member in the opposite direction, means for supplying hydraulic pressure fromfthe high pressure side Vof'said pump to supplement said resilient means, and means for automatically relieving said hydraulic pressure supplementing said resilient means when the discharge pressure of said pump reaches a predetermined pressure.

3. A variable delivery pump mechanism comprising means defining a pumping chamber, a rotor mounted for rotation in said pumping chamber, a plurality of vanes carried by said rotor, said means including a member defining a part of the wall of said pumping chamber and having a portion co-operating with said vanes to restrict the movement of liquid therebetween from the high pressure side of said pump mechanism to the low pressure side thereof, said member being disposable in oneposition corresponding to maximum volume delivery of said pump and movable in one direction from said position to reduce the delivery ofsaidpump and increase the space between said portion of said member and said rotor, said member being exposed to .a pressure within said chamber related to the discharge pressure of said pump and urging said member in said one direction, resilient means urging said Vmembery in the oppositedirection, means for employing the hydraulic pressurevat the highl pressure side of `said pump for exerting a force on said member supplementing said resilient means and substantially equal and opposite to the force exerted on said member by the pressure within said chamber, and means for automatically reducing said first named force when the discharge pressure of the pump reaches a predetermined pressure.

4. A variable delivery pump mechanism comprising means defining a pumping chamber and a second chamber disposed at right angles to said pumping chamber, a rotor mounted for rotation in said pumping chamber, a plurality of vanes carried by said rotor, said means-including a member havingy a portion extendingV into and slidably mounted in said second chamber, said member including a surface forming apart of the wall of said pumping chamber, said member being disposable in a first position corresponding to maximum delivery of said pump mechanism and movable in one direction to reduce the delivery l of said pump, resilient means urging said member to said yfirst position, said first named means also defining passage means connecting said second chamber to said pumping chamber'at the high pressure side of saidy mechanism and additional passage means adapted to vent said second chamber to a low pressure area, and valveA means controlling the iiow of liquid in said additional passage means and yieldably urged toward its closed position, said valve means being adapted to open, when the pressure in said additional passage means exceeds a predetermined value, to permit a drop in the pressurewithin said second chamber and a movement of said member in said one direction in response to the pressure within said pumping chamber acting on said surface.

5. A variable delivery pump mechanism comprising means defining a pumping chamber and a second'chamber disposed at rightangles to said pumping chamber, a rotor mounted for rotation in said pumping chamber, a plurality of vanes-carried by said rotor, said means including a member having a portion extending into and slidably mounted in said second chamber, said member including a surface forming a part of the wall of said pumping chamber, said 'member' being disposablein a first position corresponding to maximum delivery of said pump mechanism and movable in one direction to-reduce the delivery` of said pump, resilient means urging said member toy said first position, said first named means also detining passage means connecting said second chamber to said pumping chamber at the high pressure side of said Ymechanism and additional passage means adapted to vent said second chamber to a low pressure area, and Valve means controlling the iiow of liquid in said additional passage means and yieldably urged toward its closed position, said valve means being adapted to open, when the pressure in said additional passage means exceeds a predetermined value, to permit a drop in the pressure within said second 'chamberand a movement of said member in said one direction in response to the pressure within said pumping chamber acting on said surface, said surface of said member being spaced slightly outwardly from the path of movement of said vanes when said member is in said first position.

6. A variable delivery pump mechanism comprising means defining a pumping chamber and a second chamber disposed at right angles to said pumping chamber, a rotor mounted for rotation in said pumping chamber, a plurality of vanes carried by said rotor, said lmeans including a member having a portion extending into and slidably mounted in said second chamber, said member including a surface forming a part of the wall of said pumpingchamber, said member being disposable in a first position corresponding to maximum delivery of said pump mechanism and -movable inone direction to reduce the delivery of said pump, resilient means urging said member to said first position, said rst named means also dening passage means connecting said second chamber to 7 said pumping chamber at the high pressure side of said mechanism and additional passage means adapted to vent said second chamber to a low pressure `area,and valve means controlling the flow of liquid in said additional passage means and yieldably urged toward its closed position, said valve means being adapted to open, when the pressure in said additional passage means exceeds a` predetermined value, to permit a drop in the pressure Within said second chamber and a movement of said member in saidl one direction in response to the pressure within said pumping chamber acting on said surface, said passage means and said additional passage means being of a cross-sectional area such that an opening of said valve means resulting in a differential hydraulic pressure urging said lmember in said one direction.`

7. A variable delivery pump mechanism comprising means defining a pumping chamber and a second chamber disposed at right angles to said pumping chamber, a rotor mounted forrotation in said pumping chamber, a plurality of vanes carried by said rotor, said means including a member having `a portion extending into and slidably mounted in said second chambeigsaid member including a surface forming a part of the wall of said pumping chamber, said member being disposable in a first position corresponding to maximum delivery of said pump mechanism and movable in one direction to reduce the delivery of said pump, resilient means urging said member to said first position, said first named means also defining passage means connecting said second chamber to said pumping chamber at the high pressure side of said mechanism and additional passage means for connecting said second chamber to the low pressure side of said pump, and valve means mounted in said first named means for controlling iiow through said additional passage means and yieldably urged to its closed position, said valve means being adapted to open, when the'pressurein said additional passage means exceeds a predetermined value, to permit a drop in the pressure within said second chamber and a movement of said member in said one direction in response to the pressure within said pumping chamber acting on said surface.

8. A variable delivery pump mechanism comprising means defining a pumping chamber and a second charnber disposed at right angles to said pumping chamber, a ,1

rotor mounted for rotation in said pumping chamber, a plurality of vanes carried by said rotor, said means including a member having a portion extending into and slidably mounted in said second chamber, said member including a surface forming a part of the Wall of said pumping chamber, said member being disposable in a first position corresponding to maximum delivery of said pump mechanism and movable in one direction to reduce the delivery of said pump, resilient means urging said member to said first position, said first named means also defining passage means connecting said second chamber to said pumping `chamber at the high pressure side of said mechanisnf and additional passage means adapted to vent said second chamber to a low pressure area, and

valve means controlling the flow of liquid in said addifr within said second chamber being equaltothe projected area on said plane of said surface of said member.

9. A variable delivery pump mechanism comprising 8 a housing defining an inlet, an outlet, a cylindrical chamber, arcuate recesses extending circumferentially of said chamber and connecting said inlet and said outlet with said cylindrical chamber, and `a second chamber extending at right angles to and intersecting said cylindrical chamber between the adjacent ends of and communicating with said recesses, a rotor mounted within said cylindrical chamber for rotation about an axis parallel to and spaced from the axis of said cylindrical chamber in a direction toward said second chamber, a plurality of vanes mounted in said rotor, means holding said vanes in engagement with the cylindrical surface of said cylindrical chamber during rotation of said rotor, a member slidably mounted in said second chamber and movable in one direction from a first position in which it co-operates with said vanes to substantially prevent liquid fiow between said adjacent ends of said recesses, to permit said liquid flow in increasing quantities, resilient means urging said member toward said first position, the surface at the inner end of said member being exposed to a hydraulic pressure related to the discharge pressure of the mechanism and urging said member in said one direction, means connected to the high pressure side of the mechanism for supplying liquid under pressure to said second chamber to act against the opposite end of said member and supplement said resilient means, and means for automatically relieving the pressure in said second chamber when the discharge pressure of said pump reaches a predetermined pressure.

10. A pump mechanism as defined in claim 9 wherein said member has a cylindrical surface at said inner end having a radius of curvature equal to that of the cylindrical wall of said cylindrical chamber and which is adapted, when said member is in said first position, to substantially form a continuation of said cylindrical wall.

11. Apump mechanism as defined in claim 9 wherein said member has a cylindrical surface at said inner end having a radius of curvature equal to that of the cylindrical wall of said cylindrical chamber and which is adapted, when said member is in said first position, to substantially form a continuation of said cylindrical wall but is spaced slightly radially outwardly from said cylindrical wall to provide limited flow between said surface and the outer edges of said vanes and insure the application of liquid pressure to said surface.

12. A pump mechanism as defined in claim 9 wherein said member has a dimension measured at right angles to said axes substantially equal the greatest cord of a sector defined by three adjacent vanes,

References Cited in the tile of this patent UNITED STATES PATENTS 1,285,819 Smith Nov. 26, 1918 1,436,363 Crouse Nov. 28, 1922 1,444,269 Piatt Feb. 6, 1923 1,693,540 Balsiger Nov. 27, 1928 1,943,929 Rayburn Jan. 16, 1934 2,026,776 Douglas Ian. 7, 1936 2,238,062 Kendrick Apr. 15, 1941 2,538,194 Ferris Jan. 16, 1951 2,600,632 French June 17, 1952 2,600,633 French .Tune 17, 1952 2,601,829 OBrien July 1, 1952 2,606,503 Shaw Aug. 12, 1952 2,628,567 De Lancey et al Feb. 17, 1953 2,635,551 De Lancey Apr. 21, 1953 2,651,994 De Lancey et al Sept. l5, 1953 FOREIGN PATENTS 528,950 Great Britain Nov. 11, 1940