CA1187332A - Fuel pump with magnetic drive - Google Patents

Abstract

ABSTRACT
An axial air gap magnetic drive motor having a diaphragm to seal the drive motor from the pump is disclosed. The drive motor drives a posi-tive displacement pmup through a magnetic coupling on both sides of the diaphragm. The gerotor pump includes an annular backing plate member. an inlet member and a three piece pump which is rotated by the drive motor through the magnetic coupling. The three piece pump includes a male rotor gear, an annular female gear cooperatively engaging the male rotor gear and an outer annular member disposed around the annular female gear. The inside diameter of the outer annular member is eccentric a predetermined radial distance from the axial center line. The outer annular member, the inlet member and the backing plate member are pinned to one another to prevent relative movement therebetween. A pair of biasing members are mounted between the opposite end of the housing and the inlet member to urge the inlet member towards the three piece pump and the backing plate member to reduce axial clearance therebetween.

Description

7;33 ~N-This ~nvention re1ates to flu~d handling devices and more par-ticularly relates to magne~ic drives employin~ drlven posltive dfsplace~ent pumps ~or handllng fluids~

There are several kno~n pumps oP ~he type ~aYtn~ an electrlc motor and a ro~ar~y wheel drtven by the mo~r wî~h a coupl~n~ c~nststin~ o~
two gr~ups Q~ permanent magnets to prevent contam~nattQn ~f ~he ~l~id bein~
handled. One group o~ permanen~ magne~s ro~ates ~l~h and ls m~unted ~n the sha~t o~ ~he motor and the other group o~ magents is m~unted on and r~tates with the rotor wheel. In these types o~ pumps, the ~nterlQr oP the pump is sea1ed a~a~nst ths env~ronment b~ means o~ a dlaphragm of nonmagnet~.c m~tertal disposed betweell ~he ~wo groups of magn~ts. The rotor wheel is generally connec~d to a pump device.

In U.S. Pa~ent 2,970,548 ~o S. G~ Berner~ 1ssueel Febru~rY 7. l9~1~
a magnet~cally drlven cen~ri~ugal pu~p t5 d~sc1Osed~ The rotor wheel q~ the pump is coupl~d to an electric motor by two concentr~call~y mounted m~nets"
one on the shaft o~ the motor and the ot~er on the rotcr ~heel ~ ~ther ex~
amples o~ centrl~ugal pumps w~th concentrtcall~y muunted m~ne~ic drives are shown ln U.S. Patent 39205,~27 to F~ Z~rrmer~n, ~ssued Septe~be~ 14, 1965 and U.S. Patent 3,238,883 Issued to Thomas B~ 17art~n on ~larch 8, 1966. qne disadvantage o~ concentrically moun~ed magnets ts ~hat the ~iaphr~g~ wall must be made by welding a p~ece o~ sheet metal back on l~self~ HolYev~r~ tn ~L~ ~'7~3 weldtn~ t~o thln edges of sheet metal7 ~t ts d~ cul~ t~ ~ta~n a s~ati~
factory seam or ~oint~ Purther~ore, lt ts d~ ult to ~abr~cate the cyllndric~l wall to such an exact size and shape that the wall eyerywhere w~ll be ~lush agatnst the interface near the s~ator~ In vtew of these cons~derations, the magnetic gap between c~ncentrlcally m~unted magne~s must be substantially yreater than c~mparable ax~ally maun~ed ~a~ne~5 Because of the ~ncrease ln magne~ic gap for concentrlcally moun~ed magnets, there is an undeslrable increase in the loss o~ magnetic flux through the gap with a corresponding reduction ln performance and also requires lar~er diameter components to handle higher torque transfers In U.S. Patent 2g996~9~4 to G. W~ ~r~ght, issu~d ~ugust 22~ 1961 a submers~ble mo~or driven pump ~or pumping llquid fuel$ utillztng axial gap nlagnets ~s disclosed. This motor drlven pump utilizes a centrt~ugal type rotor driven by a sealed motor t~r~ugh a magnettc coupling operating between an imper~orate wall of the motor houslng. The motor pump is adapted to ~l~ with1n a variety of ~uel tanks. The dr~v~ng and driven members of the magnet~c coupling lie on opposite sides of ~he imperforate ~all, ~hich serves as a rig~d diaphragm betwecn the two magnets. Thus~ ~he dr~ven and dr~ving me~bers are separated by an axial alr gap. Another example of an axlal air gap magnetic motor with a centrlfugal pump ls dlsclosed ~n U~S.
Patent 3,223,043 to Harrts Shapiro lssued December 14, 1965.

Centrlfugal pumps have a number o~ def~cienc~es. F~rst, they are inherently high speed devices and are more eff~clent in ~andling large ~ ows and low pressure rlses. Centrifugal pumps have lowér efflci@nc~es for small flows and higher pressure rises. Secondly, the pressure r~se developed by a centrl~ugal pump is directly proportional to the speed squared~ Thus, centrifugal pumps do not produce high pressure rises at low speed. Th~rd, entrifugal pumps have a tendency to caY~tate and loose their prime. ~hen elther of these conditions occurs~ ~he centrlFu~al pump Wlll n~t pump which may result in ~enerating heat, noise, vtbrat~on and the premature fal1ure of the pump.

~ further improvement ln pumps havlns axial air gap magnetic drive motors ~s shown ln U.S. Patent 3,470,~24 to Elton ~. O'Connor, issued October 7, 1969. O'Connor dlscloses a magnetic drive pump wherein an electrically powered dr~e motor is sealed from a pump chamber and transmits by electro-magnet~c ~orces, a rotary dr1ve to a pump impeller in the pump chamber. The pump has slldlng vanes in a ~ixed caslng so that ~he liquid is directly dlsplaced withou~ requlr~ng ~he appllca~ion of centrifugal ~orce.

One maJor drawba~k of pos~tive rotary displacement pump~ is that thelr efficiency is dependent on the machinlng clearances o~ rotatlng members.
The actual clearance~ of course3 Is a function o~ the machining and assembly.
In addition, w~th low viscosity liqulds9 very close tolerances are neces~ary so as to reduce slippage caused by l~quid leaking through the pump clearances The amount of sl~p is dependent upon several ~actors. Generally, lncreased clearances result in greater slip. Thus3 slid~ng vaned pumps do not find great appl1c~t~on in pumplng low viscoslty liqulds since the sliding vanes are prone to excessive tip wear wh~ch requires ~heir frequent replacement.
In addition9 such sllding vane pos~tive rotary displacement pumps are complex, ,'~ have high ~et~n~fricti~n losses, are expenslve to make and do not provide cv~P~ .rs~
a cut off in case o~ ev~r~ss~ o~ the fluid handled.

Therefore, none of the a~oremen~loned centrtfug~l or sltdtny Yane pumps9 when used with a magnetlc drlve coupllng between the pump and the electr~c motor, d~scloses a pump suita41e for handllng fuels. In addition, ~.8'i'33~

none of the a~orementioned pumps are simple, inexpensiYe to make and provides overpressure protection to limit the discharse pressure o~ the fluid being handled. Finally, none of the aforementioned pumps are suitable for a mu1titude o~ ~lu~ds, including fuels, provide high pressure ~ ~; at low speed and voltage, have a low ~endency to cav~tate~can be easily assembled, and further provide high efficiency.

SUMMARY OF THE INVENTION

The present ~nvention is dirçcted to a pump w~th an axial air gap motor driving a positive displacement gerotor pump which provides positive lift a~ the inlet. In addition~ the gerotor pump provides hlgh pump effi-~ b~7~
ciency without hi~h friction and wear as heretofore~exper~enced ln the prior art designs. The pump is simple and ls adaptable to the necessary manufacturing clearances a~ low cos~. Furthermore, the present invention permits the use of increased axial clearances in assembling the pump wtthout sacriflcing pump efficiency or cost and is suitable for pumping multi-viscous fluids. Finally, the axial a1r gap gero~or pump prevents contamina-tton of the ~luid being handled and can easily be adapted to llmit ~he discharge pressure of the fluid being handled.

The pump has a housing with a chamber having one end ~nd an oppo-site end. The d1aphragm member is moun~ed ~nside the chamber diYiding the ~nside of the chamber ~nto a ~rst inside port~on adjacent t~ sne end and a second ins~de portion adjacent the opposi~e end. A f~rst sha~t is rotat-ably mounted in the first inside portion of the chamber. The sha~t further has one end adjacent the diaphragm member with the opposlte end hav~ng tha elec~ric motor moun~ed thereto for rotating the first shaft when energized.

3~
~ cond shaft is rotatably mounted in the second inside portion of the chamber. The second shaf-t has a first end adjacent the diaphragrn member and a second end opposite the first end. A mag-netic driving member is slidably and nonrotatably mounted on the one end of the firs-t shaft adjacent -to the diaphragm member. A
magnetic driven member is fixedly mounted on the first end of the s~!cond shaft adjacent to but spaced away from the diaphragm mem-ber. The magne-tic driven member rotates with the magnetic driv-iny mernber in response -to a force of magnetic attraction which is exerted be-tween the magnetic driving and magnetic driven member through the diaphragm member. Finally, a gerotor pump member, which is mounted on the opposite end of the second shaft, pumps fluid when the second shaft is rotated.
It is, therefore, a primary object of this invention to provide a fluid pump having an axial magnetic coupling with a nonmagnetic diaphragm member therebetween which is coupled to a gerotbr pump having an overpressurization limiter at the dis-charge port. The gerotor pump is designed to safely handle low viscosity fluids with high pump efficiency. Yurthermore, the gerotor pump provides positive lift at the inlet, is self-priming, and has multi-fiuid capabilities. Finally, the losses created by fluid friction in the pump are minimized to enhance pump efficiency.
The present invention will be further illustrated by way of the accompanying drawings, in which:-Figure 1 is a partial sectional view of a magnetic pump according to the invention;
Figure 2 is a sectional view along 2-2 of Figure 1 of the gerotor pump of the invention;
Figure 3 is a sectional view along 3-3 of Figure l;
Figure 4 is a sectional view along 4-4 of Figure l; and Figure 5 is a perspective view of a gerotor pump arrangement.

33~:
Referring to the dr~wings, there is shown a positive displacement, magnetic drive gero-tor pump, generally designa-ted by the numeral 100, which embodies the invention. The pump 100 is provided with a housing 10 with one end 12 and an opposite end 18.
The housing 10 has a chamber 20 formed therein. A diaphragm member 50 is secured by suitable means such as welding to the inside diameter 16 of the housing 10 and divides the chamber 20 into a first inside portion 22 and an opposite second inside portion 28. The first inside portion 22 is formed adjacent to the one end 12 of ~he housing 10. The second inside portion is formed adjacent to the opposite end 18 of the housing 10. A pair of bearings 32 and 34 are suitably mounted to the inside diameter of the housing 10 in the first inside portion 22. The one bearing 32 is placed adjacent to the one end 12 and the other bearing 34 is placed adjacent the diaphragm member 50. An electric motor 40, having a drive shaft 48 extending from either side of an armature 42, is rotatably mounted on the bearings 32,34. Motor magnets 44 and field windings (not shown) are mounted concen-trically with the armature 42. The motor magnets 44 and field windings are mounted to the inside diameter 24 of the first in-side portion 22 of the chamber 20. The electric motor 40 also has a commutator 46 mounted adjacen-t the one bearing 32. A
plurality of brushes 52 are conventionally connected ~ t~3~

to electr~cal contacts 54 which project ~hrough the one end 12 and is con-nected to an electric source (not shown). The brushes 52 are conventionally mounted onto the commutator 46 so as to provide elec~r;c current to the co~mutator and ~he armature 42. The field windings are also conventionally connected to the electrlc contacts (no~ shown) and thence to the electric source (not shown). The electric source may also be D.C. or alternating current with the appropriate modifications to the electrical components of the electric motor. Those skilled in the art will also recognize that the pump herein described need not be driven by electr7c source means in prac-ticing the invention and that an hydraulic motor or an air motor may also be used with appropria~e modifications.

The diaphragm member 50 ~s forme~ of a non-magnetic material for a purpose to be dascribed herein later. The diaphragm member also constitutes a fluid seal to prevent fluid leakage between the first lnside portion 22 and the second ins~de portion 28 of the chamber 20.

A first thrust button or washer 56 is mounted be~ween the one end 49 of the dr~ve shaft 48 and the diaphragm member 50. The washer abuts the d~aphragm member 50 so as to prevent the ona end 49 of the drive shaft 48 from rubbing against the diaphragm member and wearing through the diaphragm memberc An annular magnetic driving member 60 is mounted on the one end 49 of the drlve shaft 48 a~jacent to the f1rst thrust washer S6. The magnetic driving member 60 is axially slidable on the shaft 48 by a plurality of flats 62 on the inside diameter of the magnetic dr~v1ng member 60 and a plurality of cooperating flats 47 on the dr~ve shaft 48. Thus~ the magnetic drivlng member 60 may sllde axially along the shaft 48 towards the dlaphragm member 50 to compensate for production ~olerances and wear of the flrst thrust washer 56 as required. The magnetic drlving member 60 has an annular backing member 64 formed of sui~able magnetic permeable material, preferably of steel. A permanent magnet 66, preferably a ceramic permanent magnet, is made ln~o elght (8) poles and suitably mounted to the backin~ member 64 50 as to be adjacent the f~rst thrust washer 56 but spaced away from the d~aphragm member 50. Thus, there ~s an air gap 65 between the d~aphragm member and the annular magnetic dr~ving member ~0 which varies somewhat as ~ the washer~ wears away.

In the second inner portion 28 of the chamber 20 is mounted a pair of bearings 36, 38 which are suitably mounted to the houslng 10. A
driven shaft 78 is mounted in the bearings 36~ 38. The firs~ end 82 of the second or driven shaft 78 is mounted adjacent to the dlaphragm member 50 on bearing 36 and the second end 84 of the second shaft 78 is mounted on bearlng 38 adjacent to the oppos~te end 18 of the housing 10.

A second thrust button or washer 58 ls mounted bet~een the first end 82 of the driven shaft 78 and the diaphragm member 50. The second thrust button or washer abuts against the diaphragm member 50 so as to prevent the first end 82 of ~he second sha~t 78 from rubbing through and weartng against ~he diaphragm member 50.

A magnetic driven member 70 is fixedly mounted on the second sha~t 78 for rotatlon therewith. The magnet~c driven member 7d has an annular backing member 74 formed of suitable magnetical3y permeable material, pre-ferably o~ steel. A permanent magnet 76, preferably a ceramlc permanent magnet~ 1s made to have eight (8) poles and suitably mounted to the backing member 74 so as to be adjacent to th~ washer S8 bu~ spaced away a predetermined d~stance to ~orm a flxed a~r gap 75 ~rom the dlaphragm ~ 7 3 ~3~
member 50. Those skilled in the art wlll recognize ~hat any equal number of magnets may be used in the magnets 66, 76 respectively ln order to provide a magnetic coupl~ng between the magnetic drlven member and the magnetic dr~ving member. It is important, however, that one of the magnets 66 of the driving member 60 be al~gned w~th the corresponding one of the magnets 76 on ~he driven member 70. This perm~s the driving member 60 and the driven member 70 to be coupled by the flux path emitted by the magnetic attractions of one of the magnets 66 through the a~r gap 65, through the diaphragm member 50, through the air gap 75 and ~hen to one of the magnets 76. Thus, the magnets 66 are alwqys aligned with the magnets 76 and thus, no slippage occurs between the driving and driven members when one ~s rotated relative to the other. Sl~ppage between the magnets 66~ 76 respectively occurs if a force overcomes the magnet~c force there-between such as in the event that the pump is prevented from rotatlon.

On th~ second shaft 78 adiacent the second end 84 is mounted a gerotor pump 90. The gerotor pump 1s made o~ an annular backplate member 869 an inlet annular m~mber 89 and three (3) cooperat~ny posit~ve displace-ment members, that is, a male rotor gear 92, an ann~lar female member 94 and an outer annular member 96 as is best shown 1n Flgures 3 and 5.

The annular backplate member 86 ls connected to the 1n$ide d~ameter sf the second inner portion 28. The backplate member 86 has one face mounted adjacent to the driven member 70. The oppos~te ~ace has two kidney shaped - cavities 79, 80 ~ormed one oppos~te the other therein for a purpose to be i described later on herein. The second shaft ~ passes through the ~nside diameter of the backplate member. The three a~orement~oned cooperatlny members 92, 94 and 96 respectively are centrally mounted relat~ve to the axis of the second shaft ~ so as to abut the annular backplate member 86.
The male ro~or gear 92 is concentr~cally and axially sl~dable and nonrotatably ~3~8~3;~2 mounted to the second shaft. The annular female gear member 94 cooperatively engages the male rotor gear 92. The outer annular member 96 is mounted to the ~nside diameter 29 of the second ~nside portion 28 of the chamber 20.
The inside diameter 97 of the outer annular member 96 ls eccentric a pre-determ~ned radlal distance D from the long^itudlnal axis 99 passing thraugh the center line o~ ~he outer diameter 98 of the outer annular member 96 for a purpose to be discussed la~er on herein.

The annular female gear member 94 has an ou~er dlameter 95 ~hich moun~s within the inside diameter 97 ~f the outer annular member 96. The outer diameter 95 is formed so as to be undersized with the inside d~ameter 97 to provide a slight diametral clearance between the two members. This diametral clearanceg ~ormed between ~he two members, permits the ~emale tooth member 94 to float in ~he outer annular member 96. The annular fenale gear member 94 has an inner annular tooth profile 93. The inner annular tooth profile is made with one more gear tooth than the teeth 91 on the male rotor gear 92.

The male rotor gear 92 rotates concentr~cally on the second ~r drlYen shaft 78. The teeth 91 on the ma1e rotor gear 92 mesh with the inner annular tooth profile 93 of the female gear member so ~hat both the male gear 92 an~ the female gear member 94 rotate ln the same direc~lon. The male gear 92, however, advances one tooth each revolut~on o~ rotation. As the female gear member ro~ates with the male gear member 92, the teeth mesh and demesh because of the eccentrlc radial d~stance D o~ the ~nner diameter 97 relatlve to the outer annular member 96.

The gerotor pump 90 ~s mounted between the annular b~ckplate member 86 and an inlet member 89. The inlet member has tw~ kidney shaped openings 87, 88 respectively serving as lnlet and outlet open~n~s to the housing 10. Each of the kidney shaped openings 87, 88 are In ax~al al~n-ment with each o~ the kidney shaped cavit~es i9~ 80 in the annular backpla~e ~10-~ 3 3 ~
member 86. The inlet member is slidably moun~ed to th2 inside diam2ter of the second inner portion of the housing 10. The inlet member is suitably mounted to the inside diameter of the second inner portion of the housing 10 so that the inlet member is prevented from rotation w~th the gerotor S pump 90. One o~ the two kidney shaped openings 87 ls pos~tioned ln the top half portion of ~he inlet member 89 and the second k~dney shaped opening 8B
is positioned in the lower half as is shown in Figure 4. In addltlon, the annular backplate member 8fi, the outer annular member 96 and tile inlet mem-ber 89 are connected together by at least ~wo pins 4 as is well known ~n the art to prevent relative movement therebetween.

As discussed earlierJ the outer annular member 96 has an inslde diameter 97 which is eccentric a distance D to the hor~zontal dlametral axis 99 passing through the center line o~ the diameter g~ as shown ln Figure 5.
~B3v~
~ The eccentric D is positioned ~ the diametral axis 99 which splits the upper half of the inlet member~ from the lower hal~ 83 of the inlet member .

An inlet port 2 is ~ormed in an end plate member 14 moun~ed on the opposite end 18 of the housing 10 so as ~o connect the inlet k~dney shaped opening 87 for flow communicatiorl thereto. Similarly, an ou~let port 6 is formed in ~he end plate member 14 mounted on the opposite end 18 of the housing 10 so as to connect the outlet to kidney shaped opening 88 for flow communication thereto. When the gerotor pump 90 is rotated, the meshing ~n~ ~
and demeshing of the teeth causes the fluid to be pumped to be ~w~ into the volume between the rotor gear 92 and the ~emale member 94. The inlet port 2 thus provides an inlet fluid passage which is connected by suitable conduit means to the fluid to be pumped (not shown). The ou~le~ port 6 is connected by suitable condult means to a receiver (no~ shown) wh~ch receives the pressurized fluid from the pump 100. A one way fluid ~low device 8, such ~s a conventional check valve, is provided to insure one way fluid flow from the gerotor pump -through the outlet port 6 and also to prevent bleed down when the pump 100 is deactivated.
The efficiency of any positive displacemen~ pump such as herein described depends on the axial clearances of the mem-bers. In order to insure minimum axial clearance between the three cooperating gerotor pump members 92, 94 and 96, respectively, the inlet member ~9 is biased towards the gerotor pump as shown in Figure 5. For this purpose, a pair of spaced apart cavities 72 are formed in the inlet member 89 adjacent to the opposite end 18 of the housing 10. In each cavity 72 is placed a resilient member 68, which in the preferred embodiment is a spring biasing member, such as a helical spring. The resilient member 68 thus biases the inlet annular member toward the gerotor pump members 92, 94 and 96 and assures minimum axial clearance between the gerotor pump members 92, 94 and 96, respectively and the inlet annular member 89 and the backing plate member 86.
When the operation of the pump 100 is desired, the electric motor 40 is connected to the electric source (not shown).
When the motor rotates, fluid is drawn through the in-let port 2 which communicates with the inlet kidney shaped open-ing 87. Fluid is drawn into the female gear member 94 and the kidney shaped cavity 79 when the male rotor 92 meshes against the member 94 and, si.multaneously, fluid is expelled from the annular female gear member 94 and the kidney shaped cavity 80 through the outlet kidney shaped opening 88 and thence into the outlet port 6. The meshing action, which occurs upon rotation of the male rotor gear 92 coacting with the inner annular tooth profile 93 of the female gear member 94, creates .'~L.~ 7 a series of alternately expand~n~ and c~n~r~ctln~ chAm~ers ther~4P~en~
This actton causes a positive flui~ displqce~ent ~Yhen th~ pw~rp is ln ~lui:~
communicatlon wlth the appropria~e inle~ and ou~le~ por~sO The c~n~uga~ely generated tooth profiles o~ the male. ~nd ~emale gear members are in contin~
uous fluid contact during operation. Thus, upon one complete revol~tion of the ~nner member, the male rotor will have advanced one tooth wi~t~ respect to the ~emale gear member. The volume of ~lu~d displaced ln one revQlutiqn ~s proportlonal to the size of the male rotor, the degree o~ of~set D ~ith respect to the ~emale member and the thickness o~ the pump~ Thus~ the pump ~ L~ ~
.:, lOQ provides good ~ character~stics since ~luid ls drawn intv ~he unmeshed space between members 92, ~4 respectively, lmmediatelY upon relative r~tation of the members 92, ~4. The electrlcal power ~nput through the contacts leadlng to the motar causes rotation o~ the magnetic dr~vin~ member 60 through the cooperating flats 60, 47 on the drive sha~t 48~ As previously indicated, the magnetic dr~ving member 60 has a sliding f~.t on the sh.aft 48 so that changes in axial location of the armature o~ the motor will n~t increase or decrease the rubb~ng pressure o~ the magnetic driving me~ber 60 against the d1aphragm 50. The magnetlc fQrces of the magnetic drivSng member 60 are transmit~ed through the air gap 65, ~hrough ~he diaphragm member 50, through ~he air gap 75 and then to the magnet~c dr~Yen member 70 which is ~reely rotatable on the shaft 78. The second thrus~ washer 58 ~kprevents ~he dr~ven shaft 78 from rubb~ng agalnst ~he d1aphragm 50. Thus, Q
the driv~ng member 60 causes the driven member 70 to rotate w~e~er the driving member is rotated by the motor.

In the event that pressure develops ln the outlet opening 88 o~
the pump to a greater degree than is deslred, the inlet member 89 will move axlally away ~rcm the gerotor pump members 92, Q4 and 96. The member 89 moves axially away ~rom members 92, 94 and 96 by pressing aga~nst the -13~ .

-iasing member 68 towards the opposite end 18 of -the pump. As this occurs, the fluid being pumped is perrnitted to pass from the outlet ~idney shaped opening 88 to the inlet kidney shaped opening 87 thereby relieving the pressure in the fluid. The degree of biasing by the biasing member 68 can be varied to match the de-sired maximum outlet pressure that is to be generated by the pump 100 .
Those skilled in the art will recognize that the pump described herein can be used to pump low and high viscosity fluids~
Furthermore, the pump will stop pumping in the event that debris or some other foreign matter is drawn into the pump members 92 and 94 to prevent rotation of the gerotor pump 90.

Claims (22)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A compact fluid pump having motor means, said pump comprising: a housing having an internal cavity, said internal cavity having one end and an opposite end; a disc shaped diaphragm member fixedly mounted to the inside of said internal cavity and sealingly engaging said housing, said diaphragm member further dividing the inside of said internal cavity into a first sealed internal chamber adjacent said one end of said housing and a second sealed internal chamber adjacent said opposite end of said housing; a first shaft rotatably mounted in said first sealed internal chamber of said internal cavity, said first shaft further having a first end disposed adjacent said diaphragm member and a second end opposite said first end, said motor means being fixedly interconnected with said first shaft at a location therealong remote from said first end such that said first shaft is rotatably driven when said motor means is energized; a second shaft rotatably mounted in said second sealed internal chamber of said internal cavity, said second shaft having a first end disposed adjacent to said diaphragm member and a second end opposite said first end, said second shaft being axially aligned with said first shaft; annular magnetic driving means slidably and nonrotatably mounted on said first end of said first shaft, said annular magnetic driving means comprising a first annular member having an annular face disposed adjacent said diaphragm but spaced axially away therefrom and a plurality of alternatingly directed magnetic poles disposed radially about said first annular member in a predetermined angular spaced relationship; annular magnetic driven means, fixedly mounted on said first end of said second shaft, said magnetic driven means being disposed adjacent to but spaced axially away from said diaphragm member, said magnetic driven means rotating with said magnetic driving means in response to a magnetic force of attraction which is exerted between said magnetic driving means and said magnetic driven means, said annular magnetic driven means comprising a second annular member having an annular face disposed adjacent said diaphragm but spaced axially away therefrom and axially facing said annular face of said first annular member, and a plurality of alternatingly directed magnetic poles disposed radially about said second annular member in a predetermined angular spaced relationship; and gerotor pump means, fixedly mounted on said second shaft, for pumping fluid when said second shaft is rotated by said first shaft.

2. A fluid pump as claimed in claim 1, wherein said gerotor pump means further comprises: an annular backplate member fixedly mounted within said second inside portion of said annular chamber, said annular backplate member having one face adjacent said magnetic driven member and an opposite face; an inlet member mounted within said second inside portion of said chamber adjacent said opposite end of said housing; and positive displacement means, interposed said annular backplate member and said inlet annular member, for positively displacing fluid in response to the rotation of said second shaft to cause fluid flow thereby.

3. A fluid pump as claimed in claim 2, wherein said positive displacement means further comprises: a male rotor gear fixedly mounted to said second shaft for rotation therewith; an annular female gear member cooperatively engaging said male rotor gear; and an outer annular member disposed about said annular female gear member.

4. A fluid pump as claimed in claim 2, wherein said annular backplate member is pinned to said outer annular member and said inlet annular member to prevent relative movement of said annular backplate member to said outer annular member to said inlet annular member.

5. A fluid pump as claimed in claim 1, further com-prising: an inlet port mounted to said opposite end of said housing, said inlet port being fluidly connected to said gerotor pump means for supplying fluid thereto.

6. A fluid pump as claimed in claim 1 further com-prising: an outlet port mounted to said opposite end of said chamber and adjacent but spaced away from said inlet port, said outlet port being fluidly connected to said gerotor pump means for receiving fluid therefrom.

7. A fluid pump as claimed in claim 2, wherein said opposite face of said annular backplate member has portions defining a pair of oppositely spaced apart kidney shaped cavities.

8. A fluid pump as claimed in claim 2, wherein said inlet annular member having a first face adjacent said opposite end of said housing and a second face opposite said first face, said second face having portions defining a pair of oppositely spaced apart kidney shaped openings therein.

9. A fluid pump as claimed in claim 2 further com-prising: means, interposed said opposite end of said housing and said inlet annular member, for biasing said inlet annular member towards said positive displacement means and said annular backing plate member to reduce the axial clearance therebetween.

10. A fluid pump as claimed in claim 6, wherein said outlet port further comprises check valve means mounted therein for preventing fluid flow to said gerotor pump means.

11. A compact fluid pump having motor means, said pump comprising: a housing having an internal cavity, said internal cavity having one end and an opposite end; a disc shaped diaphragm member fixedly mounted to the inside of said internal cavity and sealingly engaging said housing, said diaphragm member further dividing the inside of said internal cavity into a first sealed internal chamber adjacent said one end of said housing and a second sealed internal chamber adjacent said opposite end of said housing; a first shaft rotatably mounted in said first sealed internal chamber of said internal cavity, said first shaft further having a first end disposed adjacent said diaphragm member and a second end opposite said first end, said motor means being fixedly interconnected with said first shaft at a location therealong remote from said first end such that said first shaft is rotatably driven when said motor means is energized; a second shaft rotatably mounted in said second sealed internal chamber of said internal cavity, said second shaft having a first end disposed adjacent to said diaphragm member and a second end opposite said first end, said second shaft being axially aligned with said first shaft; annular magnetic driving means slidably and non-rotatably mounted on said first end of said first shaft, said annular magnetic driving means comprising a first annular member having an annular face disposed adjacent said diaphragm but spaced axially away therefrom and a plurality of alternatingly directed magnetic poles disposed radially about said first annular member in a predetermined angular spaced relationship; annular magnetic driven means, fixedly mounted on said first end of said second shaft, said magnetic driven means being disposed adjacent to but spaced axially away from said diaphragm member, said magnetic driven means rotating with said magnetic driving means in response to a magnetic force of attraction which is exerted between said magnetic driving means and said magnetic driven means, said annular magnetic driven means comprising a second annular member having an annular face disposed axially adjacent said diaphragm but spaced away therefrom and axially facing said annular face of said first annular member, and a plurality of alternatingly directed magnetic poles disposed radially about said second annular member in a predetermined angular spaced relationship; and gerotor pump means, fixedly mounted on said second shaft, for pumping fluid when said second shaft is rotated by said first shaft; said gerotor pump means further comprising:
an annular backplate member fixedly mounted within said second inside portion of said chamber, said annular backplate member having one face adjacent said annular magnetic driven member and an opposite face; an inlet member mounted within said second in-side portion of said chamber adjacent said opposite end of said housing; a male rotor gear fixedly mounted to said second shaft for rotation therewith; an annular female gear member cooperative-ly engaging said male rotor gear; and an outer annular member disposed about said annular female gear member, said outer annular member having an inside cylindrical surface cooperating with an outside cylindrical surface of said annular female gear member, said inside cylindrical surface being disposed eccentri-cally relative to the longitudinal axis of said shaft.

12. A compact fluid pump having motor means, said pump comprising: a housing having an internal circuitry, said internal circuitry having one end and an opposite end; a disc shaped diaphragm member fixedly mounted to the inside of said internal circuitry and sealingly engaging said housing, said diaphragm member further dividing the inside of said internal cavity into a first sealed internal chamber adjacent said one end of said housing and a second sealed internal chamber adjacent said opposite end of said housing; a first shaft rotatably mounted in said first sealed internal chamber of said internal cavity said first shaft further having a first end disposed adjacent said diaphragm member and a second end opposite said first end, said motor means being fixedly interconnected with said first shaft at a location therealong remote from said first end such that said first shaft is rotatably driven when said motor means is energized; a second shaft rotatably mounted in said second sealed internal chamber of said internal cavity, said second shaft having a first end disposed adjacent to said diaphragm member and a second end opposite said first end, said second shaft being axially aligned with said first shaft; annular magnetic driving means slidably and nonrotatably mounted on said first end of said first shaft, said annular magnetic driving means comprising a first annular member having an annular face disposed adjacent said diaphragm but spaced away therefrom and a plurality of alternating-ly directed magnetic poles disposed radially about said first annular member in a predetermined angular spaced relationship;
annular magnetic driven means, fixedly mounted on said first end of said second shaft, said magnetic driven means being disposed adjacent to but spaced axially away from said diaphragm member, said magnetic driven means rotating with said magnetic driving means in response to a magnetic force of attraction which is exerted between said magnetic driving means and said magnetic driven means, said annular magnetic driven means comprising a second annular mamber having an annular face disposed axially adjacent said diaphragm but spaced away therefrom and axially facing said annular face of said first annular member, and a plurality of alternatingly directed magnetic poles disposed radially about said second annular member in a predetermined angular spaced relationship; gerotor pump means, fixedly mounted on said second shaft, for pumping fluid when said second shaft is rotated by said first shaft; an inlet port mounted to said opposite end of said housing, said inlet port being fluidly connected to said gerotor pump means for supplying fluid thereto; and an outlet port mounted to said opposite end of said chamber and adjacent but spaced away from said inlet port, said outlet port being fluidly connected to said gerotor pump means for receiving fluid therefrom.

13. A pump as claimed in claim 12, wherein said gerotor pump means further comprises: an annular backplate member fixedly mounted within said second inside portion of said chamber, said annular backplate member having one face adjacent said annular magnetic driven member and an opposite face; an inlet annular member mounted within said second inside portion of said chamber adjacent said opposite end of said housing; and positive dis-placement means, interposed said annular backplate member and said inlet annular member, for positively displacing fluid in response to the rotation of said second shaft to cause fluid flow thereby.

14. A fluid pump as claimed in claim 13, wherein said positive displacement means further comprises: a male rotor gear fixedly mounted to said second shaft for rotation therewith, an annular female gear member cooperatively engaging said male rotor gear; and an outer annular member disposed about said annular female gear member.

15. A fluid pump as claimed in claim 14, wherein said outer annular member has an inside diameter and an outside diameter, said inside diameter further being eccentric a predetermined radial distance from the longitudinal axis passing through said outer diameter.

16. A fluid pump as claimed in claim 11, wherein said annular backplate member is pinned to said outer annular member and said inlet annular member to prevent movement of said annular backplate member relative to said outer annular member to said inlet annular member.

17. A fluid pump as claimed in claim 11 further com-prising: an inlet port mounted to said opposite end of said housing, said inlet port fluidly connected to said gerotor pump means for supplying fluid thereto.

18. A fluid pump as claimed in claim 11 further comprising: an outlet port mounted to said opposite end of said chamber and adjacent but spaced away from said inlet port, said outlet port fluidly connected to said gerotor pump means for receiving fluid therefrom.

19. A fluid pump as claimed in claim 11, wherein said opposite face of said annular backplate member has portions de-fining a pair of oppositely spaced apart kidney shaped cavities.

20. A fluid pump as claimed in claim 11, wherein said inlet annular member having a first face adjacent said opposite end of said housing and a second face opposite said first face, said second face having portions defining a pair of oppositely spaced apart kidney shaped openings therein.

21. A fluid pump as claimed in claim 11 further com-prising: means, interposed said opposite end of said housing and said inlet annular member, for biasing said inlet annular member towards said positive displacement means and said annular backing plate member to reduce the axial clearance therebetween.

22. A fluid pump as claimed in claim 18, wherein said outlet port further comprises check valve means mounted therein for preventing fluid flow to said gerotor pump means.