US2537349A

US2537349A - Rotary pump

Info

Publication number: US2537349A
Application number: US56489A
Authority: US
Inventors: James P Johnson
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-26
Filing date: 1948-10-26
Publication date: 1951-01-09
Anticipated expiration: 1968-01-09

Description

J. P. JOHNSON ROTARY PUMP Filed Oct. 26, 1948 3 Sheets-Sheet l INVENTOR.

JAMES F. JOI/MSOA/ jam. 9, 1951 J, P, JOHNSQN 2537,3 19

ROTARY PUMP Filed Oct. 26, 1948 s Sheets-Sheet 2 INl-'E[\TOR.

JAMES P. JOHN-50 I I BY I MV MVAUZ ATTOBNE Jan. 9, 1951 J. P. JOHNSON 2,537,349

ROTARY PUMP Filed Oct. 26, 1948 5 Sheets-Sheet 5 JAMES R JOHNJO/V ATTORNEYS.

Patented Jan. 9,1951

' oi=F1cE ROTARY PUMP James lfJohnson, Shaker Heights, Ohio Application mm 26,1948, Serial at. 56,489

The present improvements relating generally as indicated to rotary pumps are more particularly concerned with rotary pumps having improved performance characteristics including high mechanical and volumetric efllciency 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 efllciency particularly at high rotative speeds, and the latter has the disadvantage of excessive leakage at the sides and tips of the vanes particularly at high speeds, the tips of the vanes being in line contact or at'the most in relatively narrow surface contact with the stator or rotor whereby to offer low resistance to leakage. Furthermore, such sliding vanes are subjected to considerablewear 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 traversed by the tips while in such high unit pressure contact, vis. the perimeter of the surface engaged thereby multiplied by the revolutions per minute of the stator and 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 pressurehigh speed operation at high mechanical and volumeric efliciency.

Another object of this invention is to provide a rotary pump in which a vane or like element thereof reciprocably slides slowly relative to pump members coupled thereby in accordance with the eccentricity of said pump members and 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 leadinginto the pump casing in which said pump members are rotatably supported.

Another object of this invention is to provide a rotary pump which essentially comprises an outer pump member having a running fit within innerpump member within said outer pump member and rotatably supported by the pump casing, said members beingconnected in driving relation by a driving member having non-rotatable but transversely'slidable connections with said members, such sliding occurring along rela- 3 Claims. (01. 103-121) jtively large surface areas whereby to minimize leakage or bypass therepast. 7

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 bethe pump casing and an eccentrically disposedmum. Furthermore, because of the large area"- contact between such driving and pump members, the unit pressure therebetween is relatively low, further reducing wear and heat generation.

Another object of this invention is to provide a rotary pump in which the aforesaid driving member is're'ciprocably 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.

Another object of this invention 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.

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 detailcertain illustrative embodiments of the 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 ment of the invention taken substantially along the line l-l, Fig. 2; y

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

Fig. 3 is a perspective view of the driving mem bers used in the pump of Figs. 1 and 2;,

Fig. 4 schematically illustrates the operation of the pump of Figs. 1 and 2;

Fig. 5 is a cross sectionview similar toFig. 1

(pump casing and liner omitted) of a modiflcation omitting one of the two driving members illustrated in Fig. 1; 1

Fig. 6 is a cross section view similar to Fig. 1

(pump casing and liner omitted) of a further modification illustrating the driving members embodi-' 3 reversed from the position thereof illustrated in Fig. 1;

Fig. '7 is a cross section view diametrically through another embodiment of this invention;

Fig. 8 is a perspective view of the driving members employed in Fig. 7;

Fig. 9 schematically illustrates the operation of the pump of Fig. '7;

Fig. 10 is a cross section view similar to Fig. 7 except with one driving member and with the pump casing and liner omitted;

Fig/11 is a diametrical cross section view illustrating a pump casing and adjustable liner therein adapted to be used with any of the pumps illustrated for varying the capacity thereof; and

Fig. 12 is a cross section view similar to Fig. 11 illustrating a liner which is' automatically adiusted in response to the pressure of the fluid delivered by the pump.

Referring now more particularly to the drawings and first to the pumps: illustrated in Figs. 1 through 6, 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 I and 6 closing the ends of the bore 2 and thereby defining a cylindrical chamber, said plates being provided with bushings I and 8 or like bearings for rotativeiy supporting a rotor or inner pump member 9 therein with the axis Iii 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 l2 and end plates l3 and I4 fabricated from a suitable bearing material. Said sleeve i2 is fixed in casing part I and is slotted as shown to provide openings i and I8 re pectively registering with the ports 3 and 4. Said casing part-i and cover plates 5 and I are held together to form a unitary pump casing as by the bolts and nuts i'l.

Within said sleeve I2 and surrounding said inner pump member 9 is a cylindrical outer pump member it having a close running fit with the pump chamber side and end wallsas defined by the inner surface of said sleeve l2 and the inner faces of said end plates is and I4. Said outer pump member I! is rotatable about an axis coinciding with the axis ll of the ca ing bore 2 and eccentric relative to the axis Id of said inner pump member 9. Said outer pump member I8 is formed with cimumferentially spaced passages l2 therethrough each adapted to successively communicate with ports 3 and 4 through openings l5 and it in sleeve l2 during rotation of said outer pump member. such passage leading into the corners of the generally rectangular bore 24 in said outer pump member.

The inner pump member 8 is formed with a pair of radially extending slots 2| and 22 intersecting at right angles in which are fitted for radial sliding a pair of driving

members

23 and 24 each dri ing member preferably being made in two T-shaped parts abutting-one another at their inner ends and having its outer ends formed V with laterally extending flanges 28 making sliding contact with the op osed parallel fiat sur-' faces of the bore 20 in the outer pump member ll. Said driving

members

23 and 24 are shaped as best shown in Fig. 3 with

notches

26 and 21 to permit independent slidin thereof in the slots 2| and 22 along paths at right angles to one another. Obviou ly. said driving members may each be of one-piece construction if desired where the slots 2| and 22 are such that said driving members are assembled by endwise or axial move-- have a close sliding fit with the inner surfaces of the end plates [3 and i4. It is thus apparent that said driving members divide the space within said outer member l8 into four independentcavlties each having a passage l9 leading thereinto. It is to be noted that the lateral flanges 25 of said driving members provide a wide bearing for precluding cooking and binding between the driving and-outer pump members caused by the driving of one through the other in a manner as will hereinafter appear, and further provide large area sealing surfaces to reduce bypass between such cavities to a minimum.

In the present case the inner pump member 9 is power driven through the splined shaft 28 projecting through cover plate 8 but obviously the outer pump member I! may be power driven, if desired.

As best shown in Fig. 4, the operation of the above-described pump is as follows. Considering one cavity A formed between the

driving members

23 and 24, and pump members 9 and I8 rotated clockwise it can be seen from Fig. 4, positions I-V, that the volume of such cavity A increases from a minimum to a maximum and therefore the associated passage 19 leading thereinto will be in communication with the intake opening l5 and port 3 in sleeve l2 and easing part I respectively. From position V through position VIII and thence to position I the volume of such cavity A progressively decreases from a maximum to a minimum and therefore the associated passage in is brought into communication with the discharge opening it and port 4 in sleeve l2 and easing part 1 respectively.

The other three cavities defined between the driving members and the pump members similarly increase and decrease during one revolution oi the pump members, such change in volume being I attributed to the eccentric relation of the pumpmembers and permitted by the transverse slide mounting of the driven members along paths as shown. In this way. one revolution of the driving and pump members effects intake and discharge of fluid into and from four independent cavities. Obviously. the pump assembly may be rotated counterclockwise, in which case the ports 3 and 4 are discharge and intake ports respectively.

In the modificat'on illustrated in Fig. 5, the single driving member 29, preferably of onepiece construction. forms two cavities B and C with the inner and outer p"mp members 30 and II whereby rotation of said pump members effects increase and decrease of the volumes of such cavities B and C in a manner similar to that described in connect'on with the pump of Figs. 1 through 4. As in the structure of Figs. 1 through 4, the pump of Fig. 5 is so arranged that the cavities B and C are alternately in communication with the intake and discharge ports in a pump casing (not shown) as afforded by the passages Mama said driving members being formed with laterally accommodate transverse sliding of the respective bers provided with the lateral flanges slide back and forth once along the fiat surfaces engaged thereby and the other ends slide radially in and out once in the pump member which carries the same, such sliding movements occurring between surfaces of relatively large area and being but a small fractional portion of the amount of sliding of the vane tips in conventional sliding-vane type pumps whereby to minimize leakage and friction. Furthermore, the outer pump member is, in each case, in the nature of a cylindrical plug as used in cylindrical valves having large bearing surfaces and formed with passages. alternately conn cting cavities defined in-the outer pump member with intake and discharge ports leading into the pump casing. k

The embodiment of the invention illu strated in Figs. '1. 8 and 9 comprises a pump casing I including ports 3 and 4 and a sleeve l2 with.openings i5 and i6 precisely the same as the pifmp of Figs. 1 and 2. As in Figs. 1 and 2 the pump of Fig. 7 will be preferably provided with cover plates 5 and 6 and with end plates [3 and I 4 adapted to have a sliding fit with the end faces of the driving and pump members to be presently described. As shown in Fig. '7, the outer pump member 42 of tubular form is formed with a notch 43- on its inner face with which one end of a driving member 44 extending through a radial slot 45 in the eccentrically disposed inner pump member 46 has a driving and pivotal connection. The diametrically opposed wall of sa d outer pump member 42 is formed with a notch or recess 41, the bottom wall of which is cylindrical, of radius R struck from a center preferablylocated at the bottom wall of notch 43. Said driving member 44 also has a cylindrical end face of the same radius R making surface contact with such recess 4?.

Diametrically through said inner pump member 46 and at right angles to the aforesaid slot 45 therein is another slot 49 slidably receiving another vane-like member 49 which has its opposite ends in slidable engagement with parallel diametrically opposed fiat faces 50 formed in the outer pump member 42. The last-named mem- 9 through one end thereof whereby one of the

members

44 and 49 can be positioned in the other slot and the other of said members then moved axial- 1y along its through slot into nested position with respect to said one of the members or with at least one slot sufliciently long to permit axial displacement of the member thergn to a position permitting radial insertion of the other member in'the other slot.

As shown in Fig. 'Lbaid members. 44 and 49 define four separate cavities with the

pump members

42 and 49, the former being formed with passages 53 each communicating with one of such cavities and adapted upon rotation of said member 42' to bring such cavities successively in communication with intake passage l5 and port 3 and discharge passage l6 and port 4 in said sleeve Hand casing i respectively.

Referring now to Fig. 9,the rotation of inner pump member 46 clockwise from position I to position V and corresponding driving of outer pump member 42 through the non-rotatable connection of driving member 44 with said members effects a progressive increase in the volume of cavity D and likewise rotation of

pump members

42 and 49 from position V through position VIII and ack to position I effects a progressive decrease in the volume of such cavity D. Thus, the

passage 53 leading to cavity D is successively brought into communication with the intake and discharge ports of the pump. The other three cavities of this form of pump will similarly increase and decrease in volume during one revolution of the pump members 42 and 46. Here again, as in the previously described forms of pumps, the inner pump member 46 may be ro-, tated counterclockwise in which case the port 4 becomes an intake and the port 3 a discharge.

As evident from a study of Fig. 9, the rotation of the pump members 42 and 46 effects a slow rocking r oscillation of driving member 44 her 49 is provided with cylindrical end faces pref- (about the notch 43 as ,a pivot) in cylindrical notch 41 and a slow tilting and transverse sliding of member 49 along the faces 50 of the outer pump member 42, said

members

44 and 49 and are successively brought into communication with the intake and discharge ports of the pump. The operation of the Fig. 10 pump is substantially the same as illustrated in Fig. 9 and therefore repetition thereof has not been deemed nece sary.

It is now a parent that, in the pump-structures of Figs. 7 through 10, driving members and other cavity forming members thereof simply slide back and forth slowly for relatively short distances bothtransversely and radially whereby to overcome the obiection of high vane tip speeds and excessive wear thereof as encountered with conventional sliding-vane type pumps.

In Fig. 11 there is shown the basic elements of a variable volume pump comprising a pump casing 51 having an oblon bore 58 into which leads the

ports

59 and 60 and within which casing bore a liner or-sleeve 6| is fitted, said liner being provided with axially extending

ribs

62 and 69 fitting into similarly disposed grooves 6 4 and II in said casing. 'lhreadedinto one of said ribs or said liner is a screw 86 rotatable but axially ilxed 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 68 and rotation of said screw 66 effects shifting of liner Si 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 BI is ofthe same general construction as liner H illustrated in Figs. 1 and '7 provided with slots 8! and HI respectively registering with

ports

59 and 60 and therefore any of the pump and driving member assemblies illustrated may be disposed therein. If desired, the grooves 6i 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.

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) simply by adjusting the screw 68 In Fig. 12 is illustrated a variation of the pump of Fig. 11 in which the leeve 13, 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 transversely of the casing I4 to vary the eccentricity between the pump members. One manner of accomplishing such action is to provide diametrically opposed extensions'l5 and 16 on the sleeve fitting into

recesses

71 and 18 formed in the pump casing, one such extension 1'6 being adapted to engage an adjustable abutment screw 19 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 has a recess in which is I disposed a spring 8| compressed between said sleeve" and an adjusting screw 82 also threaded in casing H and extending into recess 11 for engagement by the sleeve I3 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 i4 is provided with ports N and I5 and said sleeve 13 is provided with slots 86 and 81 respectively communicating with such ports and as indicated with reference to Fig. 11, said sleeve 13 may contain therein any of the pump and driving member assemblies herein disclosed. In Fig. 12 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 axi and at times the shoulder 88 thereof will engage the end of 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 new understandable that there is provided herein eccentrically disposed pump members one within the othe which are nonrotatably connected together thus eliminating the high velocity tip speeds'inherent in sliding-vane type pumps. Also, the provision of relatively wide surface contact and slow relative movement x 8 between the driving and pump members minimizes leakage therepast. The pumps herein disclosed also avoid the difllculties 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 angularly disposed transverse sliding connections between said driving and pump members. As 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.

Although the present improvements have been specifically described in relation to pumps in which fluid is drawn in through an intake port and discharged under pressure from a discharge port, it will be understood by those skilled in the art that the present improvements can be readily used as a motor wherein fluid under pressure entering the casing through one port effects rotation of the assembly therein, the fluid discharged from the other port being exhausted or directed to a reservoir.

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. A rotary pump comprising a hollow casing provided with intake and discharge ports leading thereinto, an outer pump member rotatable within said casin about its central axis and provided with a passage successively communicating with such ports durin rotation of said outer pump member, said outer pum member being formed with a bore including two pairs of diametrically opposed wall portions of which one pair are parallel flat surfaces and the other pair has one portion of cylindrical form of radius struck from the other portion of such other pair of opposed portions, an inner pump member rotatable within said outer pump member about an axis disposed eccentric to the axis of said outer pump member and formed with a pair of radially extending slots therethrough, and a pair of vanelike members respectively radially slidable in such slots. one of said vane-like members having its opposite ends in driving pivotal engagement with the other portion of such other pair of wall portions and transverse slidable engagement with the wall portion of cylindrical form. and the other of said vane-like member having its opposite ends in transverse slidable engagement with such one pair of wall portions, said vane-like members forming a cavity with said pump members having communication with such passage. the ends of said other of said vane-like members being of cylindrical form of diameter substantially equal to the distance between such one pair of wall portions.

2. A rotary pump comprising a hollow casing provided with intake and discharge ports leading thereinto, an outer pump member rotatable within said casing about its central axis and provided with a passage successively communicating with such ports during rotation of said outer pump member, 'said outer pump member being formed with a bore including two pairs of diametrically opposed wall portions of which one pair are parallel flat surfaces and the other pair has one portion of cylindrical form of radius struck from the other portion of such other pair of opposed portions, an inner pump member rotatable within said outer pump member about an axis disposed eccentric to the axis of said outer pump member and formed with a pair of radially extending slots therethrough, and a pair of vanelike members respectively radially slidable in such slots, one of said vane-like members having its opposite ends in driving pivotal engagement with the other portion of such other pair of wall portions and transverse slidable engagement with the wall portion of cylindrical form, and the other of said vane-like members having its opposite ends in transverse slidable engagement with such one pair of wall portions, said vane-like members forming a cavity with said pump members having communication with such passage, the endsof said other of said vane-like members being of cy- 10 lindrical form of diameter substantially equal to the distance between such one pair of wall portions, and the end of said one of said vane-like members which is transversely slidable on the wall portion of cylindrical form likewise being of cylindrical form coaxial with the aforesaid wall portion of cylindrical form.

3. The structure according to claim 2 further characterized in that the wall portion with which one end of said one of said vane-like members has a driving, pivotal connection is in the form of a notch for receiving such one end of the aforesaid I vane-like member.

JAMES P. JOHNSON.

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

UNITED STATES PATENTS Number Name Date 1,945,220 Eyston Jan. 30,1934

FOREIGN PATENTS Number Country Date 13,070 Great Britain 1884 92,979 Austria June 11, 1923 215,282 Great Britain May 8. 1924 394,422 Great Britain June 29, 1933 394,423 Great Britain June 29, 1933 414,752 Great Britain Aug. 9, 1934 539,915 Germany Dec. 5, 1931