US2574921A

US2574921A - Rotary pump

Info

Publication number: US2574921A
Application number: US56490A
Authority: US
Inventors: James P Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-26
Filing date: 1948-10-26
Publication date: 1951-11-13
Anticipated expiration: 1968-11-13

Description

J. P. JOHNSON ROTARY PUMP Nov. 13, 1951 3 Sheets-Sheet 1 Filed Oct. 26, 1948 N INVENTOR.

JANE R JOHALSO/V ATT'O/Z ME 34 5 Nov. 13, 1951 J. P. JOHNSON 2,574,921

ROTARY PUMP Filed Oct. 26, 1948 s Sheets-Sheet 2 IN VEN TOR.

JAMES P. JOHN60N MQ MM A TTO ENEY6.

NOV. 13, 1951 JOHNSON 2,574,921

ROTARY PUMP Filed on. 26, 1948 s sheetssheet s INVENTOR. 19/155 P. JOHNSON BY l9 TTOEA/E Y6,

Patented Nov. 13, f 1951 norAnr PUMP James P. Johnson, Shaker Heights, Ohio "Application,October-26, 1948, Serial No. 56,490

chanical and volumetric efliciency and capable of high speed and high pressure operation.

In the most familiar types of rotary pumps, viz. the gear pump and the sliding vane pump, the former has the disadvantage of trapping fluid on the discharge side at the point of gear intermesh resulting in noisy operation and low mechanical efiiciency particularly at high rotative speeds, and the latter has-the disadvantage of excessive leakage at the sides and ti of the vanes particularly at high speeds, the tips of the vanes being in line contact or at the most in relatively narrow surfacecontact with the stator or rotor whereby to oflfer low resistance to leakage. Furthermore, such sliding vanes are subiected to considerable wear and generate excessive frictional heat in view of the high unit pressure contact of the tips thereof with the stator or rotor and the relatively'great distance transversed by the tips while in such highunit pressure contact, ViZJthe-perimeter of thesurface engaged thereby multiplied by the revolutions per minute of the statorand'rotor relative to one another.

Accordingly, it is one of the primary objects of this invention to provide a rotary pump of a form avoiding the aforesaid difficulties and capable of high pressure-high speed pumping operation at high mechanical and volumetric efficiency.

Another object of this invention is to provide a rotary pump in which a coupling member thereof reciprocably slides slowly relative to pump members coupled thereby in accordance with the eccentricity of said pump membersand serves as a driving member between said eccentrically disposed pump members and forms with said members a variable volume cavity. In this way, a passage in one of said-pump members establishes selective communication between such cavity and ports leading into the pump casing in which said pump members are rotatablysupported.

Another object of this invention is to provide a rotary pump which essentially comprises an outer pump member having a running fit within the pumpcasing and an eccentrically disposed inner pump member within said outer pump member and rotatably supported by the pump casing, said members being connected in driving relation by a driving member having non-rotat- 6 Claims. (01. 103-160) able but transversely slidable connections with said members, such sliding occurring along relatively large surface areas whereby to minimize leakage or bypass therepast.

Another object of this invention is to provide a rotary pump of the character indicated in which the relatively small amount of such sliding consequently reduces wear and heat generation between the driving and pump members to a. minimum. Furthermore, because of the large area contact between such driving and pump members, the unit pressure therebetween is relatively low further reducingwear and heat generation.

Another object of this invention is to provide airotary pump in which the aforesaid driving member is reciprocably mounted in and on the inner and outer pump members respectively for varying the capacity of the cavities defined thereby with said pump members. Another object of this invention is to provide a rotary pump including a universal coupling between the eccentrically disposed pump members thereof for permitting rotation of each pump member about its own axis. V

Another object of thisinvention is to provide a rotary pump as aforesaid including novel means for varying the displacement thereof.

Another object of this invention is to provide a reversible rotary pump which may be operated in opposite directions without necessitating changing of any of the parts thereof.

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

To the accomplishment of the foregoing and related ends, said 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 certain illustrative embodiments ofthe invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a cross section view of one embodiment of the invention taken substantially along the line I--l, Fig. 2; i

Fig. 2 is a cross section view taken substantially along the line 22, Fig. 1;

Fig. 3 schematically illustrates the operation of the pump of Figs. 1 and 2; Fig. 4 illustrates the mode of operation of a pump similar to that of Fig. 1 except modified to omit one of the parts therein;

Fig. 5 is a diametrical'cross section view of the pump of Fig. 1 slightly modified to provide a square bore in the outer pump member and a square block portion on the inner pump member;

Fig. 6 is a cross section view of a still further modification taken substantially along the line 65, Fig. 7;

Fig. 7 is a cross section view taken substantially along line 1-1, Fig. 6;

Fig. 8' is a diametrical cross section view illustrating a pump casing and adjustable liner therein adapted to be used with the pumps illustrative for varying the capacity thereof; and

Fig. 9 is a cross section view similar to Fig. 8 illustrating a liner which is automatically adjusted in response to the pressure of the fluid delivered by the pump.

Referring now more particularly to the draw ings and first to the pumps illustrative in Figs. 1 through 3, there is shown therein a pump casing part I formed with a bore 2 therethrough and

ports

3 and 4 leading into such bore. At the opposite ends of said casing part I are

cover plates

5 and 6 closing the ends of the bore 2 and thereby defining a cylindrical chamber, said plates being provided with bushings I and 8 orlike bearings for rotatively supporting a rotor or inner pump member 9 therein with the axis I thereof eccentric relative to the axis II of such chamber formed in said casing. The aforesaid chamber may be lined if desired with a sleeve or liner I2 and end plates I3 and I4 fabricated from a suitable bearing material.- Said sleeve I2 is fixed in casing part I and is slotted as shown to pro- .vide openings I and I6 respectively registering with the

ports

3 and 4. Said casing part I and

cover plates

5 and 6 are held together to form a unitary pump casing as by the bolts and nuts I'I.

Within said sleeve I2 and surrounding said inner pump member 9 is a cylindrical outer pump member I8 having a close running fit with the pump chamber side and end walls as defined by the inner surface of said sleeve I2 and the inner faces of said end plates I3 and I4. Said outer pump member I 8 is rotatable about an axis coinciding with the axis II of the casing bore 2 and eccentric relative to the axis I I) of said inner pump member 9. Said outer pump member I8 is formed with circumferentially spaced passages I9 therethrough each adapted to successively communicate with

ports

3 and 4 through openings I5 and I 6 in sleeve I2 during rotation of said outer pump member, such passages leading to the sides of a rectangular bore 20 in said outer pump member.

In the present case the inner pump member 9 is power driven through the splined shaft 2I projecting through cover plate 6 but obviously the outer pump member I8 may be power driven, if desired.

-Non-rotatably fitted within said outer pump member I8 but slidable transversely therein is a tubular driving member 22 of rectangular cross section having openings 23 through one pair of its opposite walls communicating with two of the passages I9 and forming with the rectangular bore 20 two separate cavities each having communication with the other two passages I9 respectively.

Non-rotatably fitting within said driving member 22 is the rectangular block portion of inner pump member 9 having transverse slidable engagement therein along a path at right angles to the path of transverse sliding of said driving member within said outer pump member I 8, the

4 opposed walls of said block portion forming two separate cavities within said driving members communicating with the remaining two passages I 9 in said outer pump member through the open- 5 ings 23 in driving member 22.

In this form of the invention the short sides of driving member 22 and the long sides of inner pump member 9 are substantially equal in order that the displacement of each of the four cavities of which such sides "define" movable walls during rotation of pump-members 9 and I8 will be equal.

-'With respect to the operation of the Fig. 1 pump structure, starting at position I, Fig. 3, the cavity G progressively increases in volume to position'V whereby during this portion of one revolution, of pumpmembers 9 and I8 through driving member 22 therebetween, the passage I9 associated with cavity G is in communication with intake passage I 5 and port 3 in sleeve I2 and easing I. Thereafter, from position V to position VIII and thence to position I, cavity G decreases in volume, its passage I9 during such rotation being in communication with discharge passage I6 and port 4 in sleeve I2 and casing I. Cavity H similarly increases from minimum to maximum volume during rotation of said pump and driving members between the positions II and VI and decreases from maximum to minimum during rotation of said pump and driving members from positions VI to II, its passage I9 successively communicating with the intake and discharge ports of the pump. The other two cavities within outer pump member I8 similarly vary in volume during each revolution whereby to effect intake and discharge of fluid into and from four equal size cavities.

In the modification illustrated in Fig. 4, outer pump member 24 is provided with an axially extending rectangular bore 25 preferably square as shown with a driving member 26 non-rotatable but slidable transversely therein as shown. In this form ofthe invention said driving member 26 has a tongue and groove or like non-rotatable but transversely slidable connection with an inner pump member 21, such sliding being along a path perpendicular to the path of sliding movement of driving member 26 in outer pump member 24.

As shown, said driving member 26 divides the bore 25 into two separate cavities J and K and as evident from Fig. 4, cavity J increases in volume and cavity K decreases in volume from positions I to V and cavity J decreases in volume and cavity K increases in volume from positions V to VIII to I whereby fluid is successively drawn into and expelled from such cavities, such increase and decrease in volume of the cavities 60 having a predetermined relation to the porting in the pump as described in connection with the pump of Fig. 1. Said pump member 24 is formed with passages 28 leading into cavities J and K.

The pump illustrated in Fig. 5 is of the same 65 construction as that of Fig. 1 except that the outer pump member 29 has a square bore 30 therein in which the tubular driving member 3I is non-rotatable and transversely slidable and that the inner pump member 32 has a square 70 portion non-rotatable and transversely slidable in driving member 3|, such sliding movements as in Fig. 1 being along paths perpendicular to one another. It will be noted that although the displacement of the four cavities defined between .75 said pump and driving members are not equal pair of larger displacement cavities will increase and decrease between :minimum and maximum drawing and :expelli-ng fluid through their associated passages 33 in member 129. Thus each revolution, the delivery :of the pump is the :sum of the displacements-cr me tour cavities. 1;"

operation of the pump illustrated in Fig. will be evident tram-Fig. 3.

One of the reasons forimaking a pump as ill;-

trated .in Fig. 5 .is :to facilitate :man'ufactune thereof and to obtain va better distribution of the metalrof the pumpmembers-ZS and. 'l he pump illustrated in Figs. -6 and Fl @essentially com-prises a yar-iation .-in the posting ar ber 43 of rectangular cross section (also preferably square), said [inner pump member being "rotatable asin bushing 44 in casing part '35 about an axis eccentric of the axis-of outer pump member 4| and provided with a -spl-ined driveshaf-t portion :45 projecting exteriorlyiof casing part35. The square end of said inner pump member :is :formed with a cylindrical bore 46 and four radial passages 4-! through the wall thereof leading to such bore. v c

Extending into bore -46 and having a running fit therewith is the cylindrical extension 48 of casing part =36 provided with a pair of axially extending passages :49 and 59 respectively leading from ports 5-! and 52 in casing part 36 to

transverse slots

53 and 54 registering with passages 4'! in said inner pumpmember. AS al ban ent from -6, each passage 41 will, during one revolution of inner pumpmember 43., successively connnunicate with sol-

ts

53 and 54 and thus with ports 5| and 52 of the pump.

Between said pump members 4| and 43 is a tubular coupling member '55 nonrotatably fitted over inner pump member 43 and within bore 42 of outer pump member 4| and having transverse sliding connections with said pump members along paths perpendicular to one another. Said coupling and pump members define between them .four separate cavities, two opposed ones of which each have direct communication with one of two opposed passages 4?! and the other two opposed ones of which each have communication with one of the other two opposed passages 41 through the opposed openings .56 through the opposed walls of coupling member 55..

Inasmuch as the mode of operation of th pump of Figs. 6 and 7 is the same as illustrated in Fig. 3 except for the disposition of the passages leading from the displacement cavities to the pump-intake and discharge ports, no separate diagram .has been included. As evident, the

6 icay lties :in alternately increasin and decreasing wolume .during rotation of the pump and couplin'g members 'willaccordingly draw :fluid the'refinto :fromtthe pump intake :port and expel ilui'd "therefrom into the pump discharge port.

In the several t'forms act the invention disclosed herein, the sliding movements are but a small fractional proportion of that present in conventional sliding vane pumps and furthermore large surface areas are provided to more efie'ctively resist bypass or leakage between the several cavities in the pumps and 'to provide :a driving angle -.considerably greater than that which will induce binding or cocking.

In Fig. 8 there is shown the basic elements of a variable volume pump comprising a pump :casing 15.! :having :an oblong bore '58 into which leads 'the ports .59 and '80 and within which casing bore a liner or :s'leeve 61 is fitted, said liner being provided with axially extending ribs 62 and E3 fitting into similarly disposed grooves '64 and 65 in said --casi-ng. Threaded into one of said ribs oftsaid liner a screw 66 rotatable but axially fixed in said casing as by a pin 61 engaged in a groove in the screw and looked as by a lock nut 68. As apparent, loosening of lock nut 58 and rotation of said screw 66 efiects shifting of liner iii in casing bore 58 so that the axis of said liner may be offset or eccentric any desired amount relative to the axis of the inner pump member (not shown) adapted to be disposed therein. Said liner -61 is of the same general construction as illustrated in Figs. 1 and '5 provided with slots 69 and 10 respectively registering with

ports

59 and 60 and therefore any cf the pump and driving member assemblies illustrated may be disposed therein. If desired, the

grooves

64 and 65 may be provided with vents H and 12 to prevent trapping of fluid therein between the ends of the ribs and the bottoms of the grooves, such vents leading to the intake side of the pump casing. The liner 6| may obviously be of a form equivalent to liner 4!] in Figs. 6 and 7.

It can now be seen that the capacity of a pump may be readily varied between zero (no eccentricity between the pump members) and maximum (maximum eccentricity between the pump members).

In Fig. 9 is illustrated a variation of the pump of Fig. 8 in which the sleeve 15, in response to the pressure of the fluid delivered by the pump and acting on the pump and driving members within said sleeve, is shifted transeversely of the casing 74 to vary the eccentricity between the pump members. One manner of accomplishing such action is to provide diametrically

opposed extensions

15 and 16 on the sleeve fitting into recesses 11 and I8 and formed in the pump casing, one such extension 76 being adapted to engage an adjustable abutment screw 79 threaded in said casing and extending into recess 18, said screw determining the maximum eccentricity and thus maximum delivery of the pump, and being locked in an adjusted position as by the lock nut 80.

The other extension 15 has a recess in which is disposed a spring 8| compressed between said sleeve 13 and an adjusting screw 82 also threaded in casing 14 and extending into recess 11 for en gagement by the sleeve 13 to determine the minimum eccentricity and thus the minimum delivery of the pump, said screw being locked in adjusted position as by the lock nut 83.

The casing 14 is provided with

ports

84 and 85 and said sleeve I3 is provided with slots 86 and vane type pumps.

actuated motors as well, it being understood that 81 respectively communicating with such ports and as indicated with reference to Fig. 8, said sleeve 13 may contain therein any of the pump and driving member assemblies herein disclosed. In Fig. 9 the sleeve 13 is shown in the position it assumes when delivering the maximum for which it is adjusted by screw 19.

Under varied conditions of operation, said sleeve will shift back and forth transversely of its axis and at times the shoulder 88 thereof will engage screw 82 to provide a minimum delivery which may be zero if desired (axis of sleeve coinciding with axis of inner pump member) or any value between zero and maximum, the maximum being determined by the adjustment of screw 19.

Having thus described several embodiments of this invention it is now understandable that there is provided herein eccentrically disposed pump members one within the other which are nonrotatably connected together thus eliminating the high velocity tip speeds inherent in sliding- Also, the provision of relatively wide surface contact and slow relative movement between the driving and pump members minimizes leakage therepast. The pumps herein disclosed also avoid the difiiculties of gear pumps as previously stated. A still further feature'of the present invention resulting from the relatively wide surface contact and relatively small distance of sliding between the driving and pump members reduces the wear and heating of such sliding surfaces to a minimum. Likewise the wide bearing surfaces establish a driving angle considerably greater than one which would "induce cocking and binding.

Briefly summarized, the present invention in rotary pumps comprises providing a' casing in which pump members one within the other are rotatable about eccentrically disposed axes and in which a driving member between said pump members serves to non-rotatably connect said pump members together so that rotation'of any of said members effects rotation of all of them and consequent pumping action as permitted by the an'gularly disposed transverse slidingconnec- 'tions between said driving and pump members.

apparent, this basic thought runs through all of the forms of the invention illustrated, such various forms, of course, to be regarded as merely typical and further modifiable without departing from the spirit of the invention.

In the preceding description and in the appended claims the word pump is to be construed in a liberal sense to include fluid pressure fluid under pressure directed into one of the casing ports will drive the rotary assembly therein.-

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.

apassage'successively communicating with such portsinsuch extension'during rotation'of said inner pump member, and a coupling member between said pump members having non-rotatable but transversely slidable connections with the latter, the paths of such slidable connections being angularly disposed relative to one another, said coupling member forming with said pump members a cavity having communication with such passage.

2. A rotary pump comprising a hollow casing provided'with intake and discharge ports leading thereinto, an outer'pu'mp member and an inner pump member'within said outer pump member supported for rotation-within said casing about eccentrically disposed axes, said casing being provided at one end with a fixed cylindrical extension containing such ports and having a running fit within said inner pump member, said inner pump member extending exteriorly through the other end of said casing and being provided with four equally spaced passages successively comm'unicating with such ports during rotation of said innerpum'p member, and a coupling member between said pump members having non-rotatable but transversely slidable connections with the latter, the paths of such slidable connections being angularly disposed relative to one another,

said coupling member forming with said pump member's four independent cavities in communication with the respective passages in said inner pump member.

3. A rotary pump comprising a pair of easing parts defining a cylindrical chamber therebetween, a cylindrical extension in such chamber 'fixed to one of's'aid casing parts and having an axis" parallel to the axis of such chamber, said extension being formed with intake and discharge passages therein and with diametrically opposed transverse slots intersecting the respective passages, a rotatable inner pump member in suchphamber extending exteriorly through the other of said casing parts and having a running fit over said extension and having at least one-passage radially through the wall thereof which successively communicates with such slots during rotation of said inner pump member'on said extension, a coupling member in such chamber having a non-rotatable but transversely slidable fit oversaid inner pump member and forming with the latter a cavity having communication with such last-named passage, and an outer pump m'ember'rotatable in such chamber about "opposed transverse slots intersecting the respectivepassages, a rotatable inner pump member in such chamber extending exteriorly through the other of said casing parts and having a running fit over'said extension and having four equally spaced passages radially throug'h'the wall thereof which successively communicate with such slots'during' rotation of said inner pump memher on Said'ex't'n's'ioma coupling member in such cliamber havinga non-rotatable-but transversely 9 slidable fit over said inner pump member and forming with the latter a pair of opposed cavities having communication with one pair of diametrically opposed passages, and an outerpump member rotatable in such chamber about the axis of the latter and having a non-rotatable but transversely slidable fit over said coupling member along a path angul'arly disposed to the path of transverse sliding of said inner pump member and coupling member, said outer pump member forming diametrically opposed cavities with said coupling member, and said coupling member being formed with diametrically opposed passages communicating such last-named cav ities with the other pair of opposed passages in said inner pump member.

5. A rotary pump comprising a pair of casing parts defining a cylindrical chamber therebetween, a cylindrical extension in such chamber fixed to one of said casing parts and having an axis parallel to the axis of such chamber, said extension being formed with intake and discharge passages therein and with diametrically opposed transverse slots intersecting the respective passages, a rotatable inner pump member in such chamber extending exteriorly through the other of said casing parts and having a running fit over said extension and having at least one passsage radially through the wall thereof which successively communicates with such slots during rotation of said inner pump member on said extension, a coupling member in such chamber having a non-rotatable but transversely slidable fit over said inner pump member, and an outer pump member rotatable in such chamber about the axis of the latter and having a non-rotatable but transversely slidable fit over said coupling member along a path angularly disposed to the path of transverse sliding of said inner pump member and coupling member, said outer pump member and said coupling member forming at least one cavity therebetween, and said coupling member being formed with a passage through the wall thereof communicating such cavity with the passage in said inner pump member.

6. A rotary pump comprising a pair of casing parts defining a cylindrical chamber therebetween, one of said casing parts being formed with an integral cylindrical extension in such chamber having an axis parallel to the axis of such chamber, said extension being formed with intake and discharge passages therein and with diametrically opposed transverse slots intersecting the respective passages, an inner pump member journalled in the other of said casing parts about an axis coinciding with that of said extension and extending exteriorly of said pump, said inner pump member being provided with a rectangular portion in such chamber and a cylindrical bore having a running fit over said extension, said inner pump member being further provided with four passages radially therethrough leading from the respective faces of such rectangular portion and successively communicating ing with such slots during rotation of said inner pump member, a tubular coupling member of rectangular cross-section in such chamber having a non-rotatable but transverse slidable fit on one pair of opposed faces of the rectangular portion of said inner pump member and forming with the other pair of such opposed faces a pair of opposed cavities having communication with the one pair of passages in such other pair of opposed faces, and an outer cylindrical pump member journalled in such chamber for rotation about the axis of the latter and having a rectangular bore providing a non-rotatable but transversely slidable fit over said coupling member along a path at right angles to the path of transverse sliding between said inner pump member and coupling member, said outer pump member and coupling member forming a pair of opposed cavities therebetween, and said coupling member being formed with a pair of passages through opposed walls thereof communicating such last-named cavities with the other pair of passages in said inner pump member.

JAMES P. JOHNSON.

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

UNITED STATES PATENTS Number Name Date 1,027,139 McGeorge May 21, 1912 1,622,816 Sperry Mar. 29, 1927 1,695,975 Pelich Dec. 18, 1928 1,867,198 Waite July 12, 1932 1,944,648 Saussard Jan. 23, 1934 2,018,692 Waite Oct. 29, 1935 2,018,693 Waite Oct. 29, 1935 FOREIGN PATENTS Number Country Date 727,840 France 1932 753,827 France 1933