Bi-Directional Pump Mechanism for Balanced Flow Fluid Exchanger

Abstract

A fluid pump assembly having a rotatable vane received with a pump housing with the vane holder rotatably carrying a plurality of vanes with each vane being biased into contact with a perimeter wall of the pump housing. A fluid exchange device utilizes the fluid pump assembly to exchange fluids in a system, such as a hydraulic system or cardiopulmonary system. The fluid exchange device may include a boost pump, a flow alignment device and a bypass valve.

Description

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. 119(e) from provisional U.S. Patent Application No. 60/857,281, filed Nov. 7, 2006, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to pump assemblies and more particularly to a fluid pump assembly utilized in a fluid exchange device in communication with a hydraulic or other fluid system.

DESCRIPTION OF THE PRIOR ART

The market for fluid exchanging equipment for vehicular hydraulic fluid systems, such as power steering and automatic transmissions has undergone relatively rapid recent expansion. Many such devices have been developed for such use. One unresolved problem has been the inherent need for an inexpensive fluid exchange system which is simple and automatic to operate and which supports desirable features of some known, more complex and expensive exchange units, such as the automatic fluid flow alignment mechanism as disclosed in U.S. Pat. No. 5,472,064 to Viken and U.S. Pat. No. 6,779,633 to Viken, each patent being incorporated by reference herein.

A related but unresolved problem has been the inherent need for a fluid exchange system which is inexpensive to manufacture while being simple to operate, having an automatic fluid flow alignment structure and automatic bypass at the end of the fluid exchange procedure which will allow for the easy fluid exchange of automatic transmissions in certain automobiles which are characterized as having low flow in their fluid cooling circuit, such as certain Ford Explorers, Ford pick-up type truck, and other Ford vehicles, and some Geo Metros and small foreign designed vehicles, and certain Toyotas.

There still remains a need for a fully automatic, simple, inexpensive to manufacture fluid exchanger which has automatic flow alignment capabilities and which can be powered by a torque motor or fluid pump external to the fluid exchanger.

SUMMARY OF THE INVENTION

The present invention is directed to systems and methods for exchanging fluids of a hydraulic system, preferably while maintaining a desired fluid flow rate during an exchange procedure. Examples of hydraulic systems include power steering systems, automatic transmissions, or hydraulic circulating systems and the like of vehicles, machinery, aircraft and equipment. Other hydraulic systems include cardiopulmonary systems of animals, particularly mammals.

In one embodiment of the present invention, a fluid exchange system includes a dual chambered vane pump having extendable vanes and two ports per chamber. Additional features of an embodiment of the invention include a bypass device and means for improved exchange capacity for low flow type hydraulic systems.

Embodiments of the present invention can be constructed and arranged for the fluid pressure of the accessed hydraulic system to determine and maintain fluid alignment through the exchanger even while utilizing an accessory motor to boost the pressure of the fresh fluid being delivered to the hydraulic system to a pressure greater than a pressure of the used fluid being accessed in the hydraulic system.

One embodiment of the present invention includes a vane pump arrangement having a working chamber and a pumping chamber wherein fluid received within the working chamber causes rotation of a vane rotor thereby forcing fluid out of the pumping chamber.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic and opened side view of a fluid pump assembly of the present invention;

FIG. 2 is a schematic and perspective view a side plate used to seal the fluid pump assembly of FIG. 1;

FIG. 3 is a schematic and top view of a pump block of the fluid pump assembly of FIG. 1;

FIG. 4 is a schematic and perspective side view of a pump block of the fluid pump assembly of FIG. 1;

FIG. 5 is a schematic and top view in perspective of a top cover of the fluid pump assembly of FIG. 1;

FIG. 6 is a schematic and perspective side view of one of the vanes used in the fluid pump assembly of FIG. 1;

FIG. 7 is a schematic and top view of the vane holder of the fluid pump assembly of FIG. 1;

FIG. 8 is a schematic and perspective side view of the vane holder, and a vane spring and pin of the fluid pump assembly of FIG. 1;

FIG. 9 is a schematic view of a fluid exchange device utilizing the fluid pump assembly of FIG. 1;

FIG. 10 is a schematic view of another fluid exchange device utilizing the fluid pump assembly of FIG. 1;

FIG. 11 is a schematic view of another fluid exchange device utilizing the fluid pump assembly of FIG. 1;

FIG. 12 is a schematic view of fluid exchange device utilizing the fluid pump assembly of FIG. 1; and

FIG. 13 is a schematic view of the bi-directional flow switch assembly of FIG. 12.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic view of a fluid pump assembly 1 utilized in preferred embodiment of the present invention. Fluid pump assembly 1 provides a dual chambered vane pump with two ports per chamber. A vane holder 5 with a plurality of vanes 7 is received inside an elliptical bore 8 of a pump block 3. Pump block 3 in this instance may be molded and comprised of an acrylic type plastic compound, but can also be molded or constructed of many other materials such as various other types of plastics or hard rubber compounds, or various types of metals such as aluminum, brass or steel, or other metals, depending on the pressures, temperatures or chemical composition of the fluids being exchanged and the desired longevity of the fluid exchanger. Fluid pump assembly 1 is shown with side cover 35 removed. FIG. 2 shows side cover 35 which engages a side surface of pump block 3 upon assembly.

Vane 7 is a blade, and in this instance is constructed of an acrylic type plastic compound, but can be constructed of many other materials such as various other types of plastics or hard rubber compounds, or various types of metals such as aluminum, brass or steel, or other metals. In this instance vane holder 5 is also constructed of an acrylic type plastic compound, but which can be constructed of many other materials such as various other types of plastics or hard rubber compounds, or various types of metals such as aluminum, brass or steel, or other metals. Vane holder 5 in this embodiment holds a total of twelve vanes, with the additional eleven vanes (not specifically numbered) constructed to be the same as vane 7.

Vane holder 5 is provided with 2 springs per vane 7 that are held in cavities provided (shown in FIG. 8 as spring 17 and cavities 37, 39). Spring 17 provides a bias force causing the vanes 7 to extend to meet the walls of elliptical bore 8 of pump block 3, thereby providing adequate sealing. Other suitable mechanisms can be used to provide extension to the vanes and these include providing fluid pressure to the inside of the vane holder to force the vanes outward during operation of a vane pump mechanism. For example, vanes 7 may be biased outwardly by an internal fluid pressure supplied to an inner surface of vanes 7 via a conduit.

The clearances provided between vane slots 6 and vanes 7 are adequate to allow vanes 7 to freely move into and out of slots 6 without allowing undue wobbling or fluid leakage through the inside of the vane slots and not too tight to cause undue resistance to movement. The force provided by spring 17 is great enough to provide adequate sealing between vanes 7 and the wall surface of the elliptical bore 8 of pump block 3 but not too great to cause undue resistance to movement. In one embodiment, vane 7 is inserted in slot 6 that is molded into vane holder 5, such as via a precision plastic molding process

FIG. 1 shows pump block 3 includes a bottom cover 11 which is fluidly sealed to its bottom side by the use of fasteners 13. Pump block 3 has a top cover 9 which is secured and fluidly sealed to its topside by use of fasteners (not shown). The top and bottom sides of pump block 3 are provided with female threads adapted to usefully engage fasteners 13.

Top cover 9 has two ports provided, port 23 and port 25. Bottom cover 11 has two ports provided, port 19 and port 21. Each of the ports of the top cover 9 and bottom cover 11 has a conduit attached to it by conventional attachment and sealing methods, in this case a hose barb and push lock and rubber type hydraulic hose is used. These four conduits are not numbered in FIG. 1 though specifically numbered and identified in each of the four embodiments shown in FIGS. 9, 10, 11 and 12.

FIG. 3 is a schematic and top view of pump block 3 showing the arrangement and configuration of block ports 24 and 26.

FIG. 4 is a schematic and perspective side view of pump block 3 showing the arrangement and configuration of block ports 20, 22, 24 and 26 and the various female threads used to secure the top and side covers to pump block 3, such as a female tread 49 and a female thread 51.

Pump block 3 has four internal ports provided to it, which are in this instance molded, but can be machined. These consist of block ports 20, 22, 24 and 26. Pump block 3 is also provided with a plurality of female threads 49, 51. Threaded fasteners engaging threads 49, 51 are used to secure side cover 35 to the side of pump block 3. In addition the clearances provided between the vanes and the side covers such side cover 35 are tight enough to provide suitable sealing to left chamber 2 and right chamber 4 with causing too much resistance to movement.

FIG. 7 is a schematic and top view of the vane holder 5 of the fluid pump assembly 1 of FIG. 1 and shows the arrangement and configuration of spring cavities 37, 39, 41, 43, 45 and 47. Fluid pump assembly 1 is defined by right chamber 4 and left chamber 2 which are provided by the elliptical bore of pump block 3.

A flexible type rubber such as a nitrile type compound or flexible type plastic such as nylon can be molded to form an impeller to be used in place of the vane holder 5 with its vanes and springs. Using such flexible rubber or plastic type impellers will provide less longevity, but because it is less expensive to manufacture it allows the fluid exchanger device 10 to be manufactured and at a lower price. During the rotation of a flexible rubber or plastic type impeller, its vanes will deflect to a decreased extension off of the walls of elliptical bore 8 as its diameter is reduced, and will extend to meet the wall of the elliptical bore 8 as its diameter is increased and thereby will provide progressively increased or decreased fluid volumes between those rubber vanes to provide the pumping actions required of fluid pump assembly 1 which are threefold fold (referring to FIGS. 1 and 9). During operation, fluid pump assembly 1 pumps used fluid 107 out of the upper part of chamber 2 and into waste receptacle 53 through a waste conduit 29 which is connected to port 23, and pumps fresh fluid 63 out of fresh fluid reservoir 55 and into the upper part of chamber 4, and pumps that fresh fluid 63 out of the upper part of chamber 4 into the lower part of chamber 4 and into reservoir assembly 81, through port 21.

FIG. 8 also shows a perspective side view of vane holder 5 and pin 42 having approximately two-thirds of its length inserted into hole 40 of vane holder 5. The other remaining length is inserted into a hole (not shown) provided to the inside center of a side cover 35 of FIG. 2 which keeps vane holder 5 aligned within pump block 3 as it rotates. Another pin (not shown) similar to pin 42 is inserted into a hole (not shown) on the opposite side of vane holder 5. The other remaining length is inserted into a hole (not shown) provided to the center of the other side cover (not shown) which keeps vane holder 5 aligned within pump block 3 as it rotates. Vane holder 5 has 12 identical slots provided to it which are the same as a slot 6 as shown in FIG. 8 and each slot has two identical spring cavities provided which receive springs 17 and slots are provided with two cavities 37 and 39. Side cover 35 is provided with eight holes (one of which is shown as a hole 36) through which a suitably sized fastener (not shown) is inserted therethrough to secure side cover 35 to pump block 3. There is another identical side cover (not shown) which is a mirror construct of side cover 35 and which is provided to seal the opposite side of pump block 3.

In one embodiment, vane 7 is inserted in slot 6 that is molded into vane holder 5, such as via a precision plastic molding process.

FIG. 9 is a schematic view of fluid exchange device 10 configured for exchanging the fluid of vehicular power steering systems which features a float operated bypass valve. Flow exchange device 10 is configured for exchanging the fluid of moderate to higher flow hydraulic circuits, such as vehicular power steering systems, and moderate to higher flow automatic transmissions, such as off-road vehicles and commercial trucks. Fluid exchange device includes automatic fluid flow alignment and bypass capabilities.

As shown in FIG. 9, fluid pump assembly 1 is shown within fluid exchange device 10. A portion of a power steering system is shown in FIG. 9. A power steering pump and steering gear mechanisms are not shown. The power steering system is accessed at reservoir assembly 81, which has a cap 83 with a vent 59 and a dipstick 87 integral to it. Complete power steering system configurations are understood by those skilled in the art.

Reservoir assembly 81 has filler neck 85 to which fresh fluid can be added as indicated by dipstick 87. Reservoir assembly 81 has port 89 through which used fluid 107 which has been circulated through the power steering system and has been returned to its source to be held in reservoir assembly 81. During normal operation of the power steering system, fluid return hose 91 is connected and held in place to be fluid tight at port 89 by use of hose clamp 101, which in this instance is a screw clamp, although there are a number of other types which are also typically used such as circumferential spring clamps. Reservoir assembly 81 has suction hose 105 connected to it at a supply port 106 through which used fluid 107 is supplied to the power steering pump (not shown) which in turn pressurizes it to deliver power to the steering mechanism (not shown), after which used fluid 107 is returned back to the fluid reservoir assembly 81 through fluid return hose 91.

FIG. 9 shows fluid return hose 91 to have been disconnected from port 89 and reconnected to male adapter 93 comprising a flexible hose terminating in a rigid nipple (not shown) and fixedly inserted into fluid return hose 91 and secured to be fluid tight by hose clamp 95 which is in this case a screw clamp. Male adapter 93 has male quick connector 98 (only partially shown) that has been inserted into female quick connector 97, which is connected to a used fluid conduit assembly 33 which is flexible for at least a significant portion of its length. Female adapter 99 is comprised of a flexible rubber type hose with male quick connector 104 at one end (only partially shown). Male quick connector 104 has been fixedly inserted into female quick connector 103, which is connected to fresh fluid conduit assembly 31 which is flexible for at least a significant portion of its length.

Used fluid conduit assembly 33 is connected to fluid pump assembly 1 at port 19 and to bypass valve assembly 75 at port 94. Fresh fluid conduit assembly 31 is connected to fluid pump assembly 1 at port 21 and to bypass valve assembly 75 at port 96. Bypass valve assembly 75 is connected and secured to be fluid tight to a fresh fluid reservoir assembly by use of conventional means, which in this case is the use of several bolts and a rubber type gasket, with said bolts passing through the top side of reservoir body 73 of the fresh fluid reservoir assembly 55 and into female threads provided to bypass valve assembly 75 at its top side (not shown) and with said rubber type gasket sandwiched in between the lower wall of fresh fluid reservoir assembly 55 and bypass valve assembly 75.

Bypass valve assembly 75 has valve slide 77 that is attached to float 79 by fastener 80, with valve slide 77 adapted to slide inside valve body 76 in response to changes in the volume of fresh fluid 63 contained in fresh fluid reservoir assembly 55. Float 79 has a lower surface serving as a sealing surface when float 79 drops to its lowest level as the supply of fresh fluid 63 is depleted. This lower sealing surface blocks and seals supply port 64 when float 79 drops to its lowest level as the supply of fresh fluid 63 is depleted and makes contact with supply port 64. Valve body 76 has bore 74 and bottom plug 78 which is fluid tight.

During an exchange procedure, as the fluid level of fresh fluid 63 rises with a increase in volume and falls with a decrease in volume, so too the float 79 responds accordingly and moves valve slide 77 with it. Valve slide 77 has internal port 88 which is placed in alignment to connect used fluid conduit assembly 33 with fresh fluid conduit assembly 31 when float 79 drops to a level associated with depletion of the fresh fluid 63 held in fresh fluid reservoir assembly 55.

Supply port 64 of fresh fluid reservoir assembly 55 has suction hose 72 connected to it. Suction hose 72 is connected at its other end to fluid pump assembly 1 at a port 25. Waste conduit 29 is connected at one end to fluid pump assembly 1 at port 23 and open at its other end to discharge used fluid 65 into waste receptacle 53 which can be easily emptied in an environmentally safe and operator convenient manner.

The embodiment of FIG. 9 can be used to conveniently exchange the fluid of power steering systems as easy access is typically provided to the inlet port of reservoir assembly 81, port 89, and fluid return hose 91. Thus no automatic fluid alignment mechanism capability is needed since the operator of the fluid exchange system can easily and quickly make the correct connections of conduit assemblies 31 and 33 to their respective proper locations. In the embodiment of FIG. 9 vane holder 5 rotates in clockwise direction only.

When hydraulic systems do not provide for reliable, quick and easy identification of an outflow port and an inlet port for connecting the fluid exchanger to, automatic fluid flow alignment between the fluid exchanger and the hydraulic circuit being accessed is essential and is readily provided in the fluid exchange devices 10 of FIGS. 10, 11 and 12. In these embodiments the vane holder 5 can rotate in either direction and is determined by how the fluid exchange device 10 has been connected to the accessed hydraulic circuit. Typically the operator of the fluid exchange device 10 cannot quickly and easily identify the direction of fluid flow of the accessed hydraulic circuit, especially the cooling circuit of an automatic transmission.

FIG. 9 shows the fluid exchange device 10 connected in proper alignment to exchange the fluid of a power steering system. The engine of the vehicle is turned off when fluid return hose 91 is disconnected from port 89 and when female adapter 99 is connected to port 89, and when male adapter 93 is connected to fluid return hose 91. Fresh fluid reservoir assembly 55 has a cover assembly that has cap 69 with vent 57. Cover assembly 67 is held in place on top of a reservoir body 73 by retainer clip 70 and retainer clip 71. Cap 69 is removed from fresh fluid reservoir 55 and the required type of power steering fluid is poured down or pumped into the fresh fluid reservoir assembly 55 in the desired volume. Once fresh fluid reservoir assembly 55 has been filled and cap 69 has been replaced, waste receptacle 53 is placed at an end of waste conduit 29 to receive used fluid during the exchange procedure.

The power steering system is rendered operative upon starting the vehicle. While the fluid exchange is occurring the operator may choose to rotate the steering wheel from one side to the other to exchange any power steering fluid which could otherwise remain in the steering mechanism. Operation of the vehicle's power steering system causes used fluid 65 from the power steering system that is normally returned back into reservoir assembly 81 to be discharged instead into male adapter 93 and then into used fluid conduit assembly 33. Used fluid 65 then passes through used conduit fluid assembly 33 into port 19 and then into block port 20 (see FIG. 1) and into the lower part of left chamber 2, causing the vane holder 5 and its vanes 7 to rotate clockwise within elliptical bore 8 of pump block 3.

As vane holder 5 and its vanes rotate in chamber 2 the vanes maintain contact with the surface of elliptical bore 8 and move outward under spring pressure as they approach the largest diameter of elliptical bore 8 and are pushed deeper into their respective slots while compressing the springs such as spring 17 as they are compressed inward by the decreasing diameter of elliptical bore 8. This causes a progressive expansion of fluid volumes within each pair of vanes followed up to a maximum, followed by a progressive retraction of such volumes down to a minimum, and then again with a progressive expansion of fluid volumes within each pair of vanes followed up to a maximum in a continuing cycle as vane holder 5 and its vanes rotate in the elliptical bore 8. Therefore as vane holder 5 and its vanes 7 rotate clockwise, used fluid 65 passes to the upper side of chamber 2 and is forced into block port 24, through port 23 and into waste conduit 29 to be deposited in waste receptacle 53. And at the same time fresh fluid 63 is delivered from fresh fluid reservoir 55 through supply port 64, into and through suction hose 72, then into and through port 25. Fresh fluid 63 then flows into and through block port 26, into and through the upper side of chamber 4 of elliptical bore 8, into and through the lower side of chamber 4, and into and through block port 22. Fresh fluid 63 then flows into and through fresh fluid conduit assembly 31, into and through female adapter 99, and then into and through port 89 of reservoir assembly 81 to mix with and dilute used fluid 107.

Thus the used fluid pressure provided by the accessed hydraulic circuit, in this instance a power steering system, causes vane holder 5 and vanes 7 to rotate and pump fresh fluid from fresh fluid reservoir assembly 55 into reservoir assembly 81. The arrows shown in FIG. 9 depict the direction of fluid flow through the fluid exchange assembly 10. Because there is some internal leakage from chamber 2 through to chamber 4, there is some mixing of used fluid 107 with fresh fluid 63. This mixing may be significant during the first part of the fluid exchange and is similar to the manner in which fresh fluid 63 dilutes used fluid 107 within reservoir assembly 81 and the rest of the power steering system. As the fluid exchange procedure reaches its end, almost all of used fluid 107 has been successfully diluted with fresh fluid 63. At that point the issue of such dilution is no longer a factor. For most vehicular power steering systems of automobiles, the operator of fluid exchange device 10 can obtain a complete or very near complete dilution of power steering fluid 107 with fresh fluid 63 by using between 2 and 4 quarts of fresh power steering fluid added into fresh fluid reservoir assembly 55. In general, vehicular power steering systems provide enough fluid pressure to operate fluid pump assembly 1.

As fresh fluid 63 is pumped out of fresh fluid reservoir 55, its fluid level drops until float 79 moves valve slide 77 downward to align its internal port 88 between used fluid conduit assembly 31 and fresh fluid conduit assembly 33, establishing a fluid bypass between these conduit assemblies. At the same approximate time float 79 drops to block supply port 64 when the rubber lower surface of float 79 makes contact with and seals supply port 64. The fluid exchange device 10 is now operating in a bypass mode where used fluid 107 is circulated from fluid return hose 91, into and through male adapter 93, into and through used fluid conduit assembly 33, into and through bypass valve assembly 75 via internal port 88 of valve slide 77, and then into and through fresh fluid conduit assembly 31, then into and through female adapter 99, and then into port 89 to be deposited in reservoir assembly 81, without fluid pump assembly 1 being operative. Bypass valve assembly 75 can be fitted with a magnetic switch in its valve body 76 with a corresponding magnet fitted into its valve slide 77, arranged to become aligned when valve slide 77 reaches its lowermost bypass position upon the depletion of fresh fluid 63. This magnetic switch can be connected in series to a battery and a blinking LED and a buzzer, which will be activated by the magnetic switch to alert the operator when the bypass mode of operation has been attained. At this point the operator can stop the vehicle's engine, rendering the power steering system inoperative.

The operator then disconnects the female quick connectors 97 and 103 from their corresponding male quick connects 98 and 104 respectively. The operator then disconnects female adapter from port 89, disconnects male adapter 93 from fluid return hose 91, and reattaches fluid return hose 91 to port 89 to be rendered fluid tight using hose clamp 101. The operator may then start the engine to render the power steering system operative. Cap 83 of reservoir assembly 81 may be removed to provide access to dipstick 87 in order to determine the fluid level of reservoir assembly 81. The fluid exchange procedure ends after any additional new fluid is added to reservoir assembly 81.

The fluid exchange device 10 of FIG. 10 can be used to exchange the fluid of power steering systems and certain higher flow automatic transmissions, and is especially suitable for such as those of larger design automotive transmissions, most commercial truck automatic transmissions, and the automatic transmissions of off-road four-wheel-drive vehicles and high performance vehicles, such as used in the sport of drag racing, as well as other hydraulic circuits with higher flow rates where the direction of fluid flow is unknown. As the fluid exchange device of FIG. 10 automatically aligns the fluid flow of the fluid exchanger with the direction of fluid flow within the hydraulic system being accessed, the operator does not need to determine the direction of fluid flow in the hydraulic circuit being accessed.

The fluid exchange device 10 of FIG. 10 shares most of the parts of the embodiment of FIG. 9 with a few exceptions. FIG. 10 shows fluid exchange device 10 which utilizes fluid pump assembly 1, two conduit assemblies, conduit assembly 231 and conduit assembly 233, which are similar to the conduit assemblies 31 and 33 of FIG. 9 respectively, and shares bypass valve assembly 75, fresh fluid reservoir assembly 55 with its float 79, with its cap 69 with vent 57, and with its cover assembly 67 and retainer clips 70 and 71. This embodiment also utilizes waste receptacle 53. Used fluid within waste receptacle 53 can be handled in an environmentally safe manner, such via recycling.

The fluid exchange device 10 of FIG. 10 has additional parts not found in the fluid exchange device 10 of FIG. 9 to provide an automatic flow alignment feature. Fluid exchange device 10 has a supply conduit assembly 119 that is connected at one end to supply port 64 of fresh fluid reservoir assembly 55, and at its two other ends to check valve 115 and check valve 117, respectively. A left upper conduit assembly 125 is provided and connects at one end to fluid pump assembly 1 at port 23 and connects at its other end to check valve 117 and priority valve assembly 109 at port 100. A right upper conduit assembly 127 is provided and connects at one end to fluid pump assembly 1 at port 25 and connects at its other end to check valve 115 and priority valve assembly 109 at port 102. A waste fluid conduit 121 is provided and is connected at one end to priority valve assembly 109 at middle port 108 and its other end is arranged to discharge used fluid 65 from the accessed hydraulic circuit into waste receptacle 53, which is provided for easy and environmentally safe transport and disposal. Priority valve assembly 109 has valve slide 111 with springs protruding offset from the center of either end such as a spring 113. These offset springs 113 at each end of valve slide 111 causes valve slide 111 to rest in the center of priority valve assembly 109 thus blocking access to waste conduit 121 and insuring proper operation of the priority valve assembly 109.

The fluid exchange device 10 of FIG. 10 has the same female quick connectors of FIG. 9 connected to its two flexible fluid exchange hoses at one of their ends each, conduit assembly 231 and conduit assembly 233. These female quick connectors 97 and 103 each receive one of a pair of matching male quick connector such as those shown in FIG. 9, male quick connector 98 and male quick connector 104 which in turn are connected to adapters that permit connection to the hydraulic circuit being accessed for a fluid exchange (not shown).

Conduit assembly 231 is connected at one of its other end to port 19 of fluid pump assembly 1, and at its other end to bypass valve assembly 75 at port 96. Conduit assembly 233 is connected at one of its other end to port 19 of fluid pump assembly 1, and at its other end to bypass valve assembly 75 at port 94.

The fluid exchange device 10 of FIG. 10 can be connected to a hydraulic circuit which has been opened to provide two temporary access ports, one which can provide communication with the pressure or upstream side of the hydraulic circuit, and the other one which can provide communication with the downstream or return side of the hydraulic circuit (not shown). One suitable adapter is then connected to each of these temporary access ports (not shown) and then each adapter is connected to one of the female quick connectors 97 and 103. These connections are typically made without the operator of the fluid exchanger determining which temporary access port is the pressure side of the hydraulic circuit or which is the return side of the hydraulic circuit. The hydraulic circuit is opened and the fluid exchanger is connected to it while the hydraulic circuit has been rendered inoperative, for example by turning off the vehicle being serviced.

After the fluid exchange device 10 has been connected to the opened hydraulic circuit and fresh fluid reservoir assembly 55 has been filled with the proper volume and type of fluid required for the hydraulic circuit being serviced, the hydraulic circuit is energized, for example by turning the vehicle on. This causes used fluid 65 to be pumped into either conduit assembly 231 or conduit assembly 233. If used fluid 65 is pumped into conduit assembly 233, it passes through it and into port 19 of fluid pump assembly 1, and then through the left chamber 2 of fluid pump assembly 1 to exit through port 23 to pass through left upper conduit 125. The fluid is blocked at check valve 117 and proceeds to pass into and through left port 100 of priority valve assembly 109 where it moves valve slide 111 to its right most position, allowing used fluid 65 to pass through middle port 108 to enter and pass through waste conduit 121 to be discharged into waste receptacle 53.

As fluid 65 passes through fluid pump assembly 1 it causes vane holder 5 and vanes 7 to move clockwise whereby causing fresh fluid 63 to be drawn from fresh fluid reservoir assembly 55 through supply port 64 to flow into supply conduit 119 where it is blocked at check valve 117 by the pressure provided by the accessed hydraulic circuit. Fluid 65 flows through check valve 115 to pass through right upper conduit 127 to flow into port 25 of fluid pump assembly 1. Fluid 63 then passes through chamber 4 of fluid pump assembly 1, then flowing out of port 21 into and through conduit assembly 231 and delivered to the return side of the accessed hydraulic circuit.

Fluid exchange of fresh fluid 63 within fresh fluid reservoir assembly 55 for used fluid 65 of the accessed hydraulic circuit can continue until the volume of fresh fluid 63 becomes depleted enough to cause float 79 to drop and create a fluid bypass condition by establishing a connection between conduit assembly 233 and conduit assembly 231. At the same approximate time a bottom of surface of float 79 come to rest upon supply port 64 thereby blocking it and sealing it. This stops fluid pump assembly 1 from pumping and the fluid exchange device 10 operates in bypass mode. The operator can then render the accessed hydraulic circuit inoperative, disconnect conduit assemblies 231 and 233, disconnect the adapters, and reconnect the hydraulic circuit. The operator may then check the fluid level of the reservoir of the hydraulic circuit and add fluid as necessary. The fluid exchange is then complete.

If conduits 231 and 233 were connected to the accessed hydraulic circuit in opposite fashion (FIG. 10 shows just the opposite), vane holder 5 and its vanes 7 would rotate in the opposite direction, counterclockwise, fresh fluid 63 would instead be blocked at check valve 115 and would pass through check valve 117 into port 23 of fluid pump assembly 1, out of fluid pump assembly 1 at port 19 to flow into and out of conduit assembly 233, while used fluid 65 would flow through conduit assembly 231 into fluid pump assembly 1 at port 21, through fluid pump assembly 1 and out of it at port 25, into right upper conduit 127, through right port 102 of priority valve assembly 109, out of middle port 108, and into and through waste fluid conduit 121. Because this embodiment automatically aligns itself to the direction of fluid flow in the hydraulic circuit based on how it was connected, the operator can connect it to the opened hydraulic circuit with no concern for direction of fluid flow that is a great convenience.

FIG. 11 is a schematic view of another fluid exchange device 10 which features bi-directional motor 129 coupled to the fluid pump assembly for decreasing the time needed to complete a fluid exchange procedure, useful for example when exchanging the fluid of lower flow hydraulic circuits such as certain automatic transmissions that circulate fluid in their cooling circuit at a relatively low flow. Fluid exchange device 10 of FIG. 11 includes automatic fluid flow alignment and bypass capabilities.

Pump motor 129 in this case is bi-directional 12-volt DC electrical motor and has a pair of leads 131. Pump motor 129 is coupled to vane holder 5 of fluid pump assembly 1 with a magnetic coupler that is suitably sealed to prevent fluid leakage out of fluid pump assembly 1. Other kinds of couplers can be used such as metal or rubber or even a fluid type coupler. A pneumatic motor can be substituted for electric pump motor 129.

The fluid exchange device 10 of FIG. 11 includes fluid pump assembly 1, priority valve assembly 109, supply conduit 119, check valves 115 and 117, upper left conduit 125 and upper right conduit 127, and waste receptacle 53.

The magnetic coupler (not shown) allows vane holder 5 to slip and rotate faster than pump motor 129 if the fluid pressure of the fluid circuit having its fluid exchanged significantly exceeds the rotational ability of pump motor 129. Pump motor 129 is 12 volt DC that allows it to be easily controlled, for example, by a MOSFET-type controller circuit that is mounted on an integrated circuit board assembly 149. Integrated circuit board 149 is connected electrically by wire 150 to power supply assembly 151 which is connected to electrical wire 153, which has a hot, a neutral and a ground, which is connected to an electrical supply plug 155 and which is in turn connected to a 120 VAC current supply (not shown). Integrated circuit board 149 contains a microprocessor and MOSFET-type circuitry (not shown but well understood by those skilled in the art) that allows it to process sensor signals and selectively operate and vary the speed of pump motor 129. There is an on-off switch (not shown) connected to the integrated circuit board assembly 149 that energizes the integrated circuit board assembly 149 when turned to its on position. The integrated circuit board assembly 149 also contains a buzzer that when activated alerts the operator that the fluid exchange procedure is completed.

Fresh fluid reservoir assembly 55 contains an a supply of fresh fluid 63 and has cover assembly 67 held in place by retainer clips 70 and 71. Cover assembly 67 has cap 69 having vent 51. Fresh fluid reservoir assembly 55 has float switch 141 with a pair of leads 143 and which is mounted and fluidly sealed through the lower sidewall. Fresh fluid reservoir assembly 55 has supply port 64 that is connected to supply conduit 119. Supply conduit 119 is connected at its other ends to check valve 115 and 117. Port 23 of fluid pump assembly 1 is connected to a left upper conduit 125 and port 25 of fluid pump assembly 1 is connected to a right upper conduit 127. Conduit 125 is connected at its two other ends to check valve 117 and port 100 of priority valve assembly 109. Conduit 127 is connected at its two other ends to check valve 115 and port 102 of priority valve assembly 109. Waste fluid conduit 121 is connected to middle port 108 of priority valve assembly 109 and one end and its other end is arranged and positioned to be able to discharge used fluid 65 into waste receptacle 53.

Port 19 of fluid pump assembly 1 is connected to conduit assembly 233 providing fluid communication to flow switch 137 with a pair of leads 139, check valve 205, and pressure transducer 169 with a pair of leads 171. Conduit assembly 233 is connected at another end to female connector 97 and at another end to valve 145 with a pair of leads 147. Valve 145 is a two position, two-way solenoid operated on/off valve that is configured to be normally open when its solenoid is not energized and creates a bypass connection when energized.

Port 21 of fluid pump assembly 1 is connected to conduit assembly 231 providing fluid communication to flow switch 133 with a pair of leads 135, check valve 206, and pressure transducer 165 with a pair of leads 167. Conduit assembly 231 is connected at another end to female connector 103 and at another end to valve 145.

Integrated circuit board assembly 149 has a female multi-wire socket 157 and a female multi-wire socket 161 to which a male multi-wire plug 159 and a male multi-wire plug 163 connect, one to each respectively. Female multi-wire socket 157 and counterpart male multi-wire plug 159 both are configured for 10 sensor related wires which include pair of leads 139 of flow switch 137, pair of leads 135 of flow switch 133, pair of leads 171 of transducer 169, pair of leads 167 of transducer 165, and pair of leads 143 of float switch 141. Female multi-wire socket 161 and counterpart male multi-wire plug 163 are both configured for four wires related to selectively delivering current which include the pair of leads 147 of valve 145 and the pair of leads 131 of pump 129.

After the fluid exchange device 10 of FIG. 11 has been properly connected to the hydraulic circuit, the operator determines whether fresh fluid reservoir assembly 55 has a proper grade and quantity of fresh fluid 63 with reference to the particular vehicle being serviced. The operator then energizes the hydraulic circuit to circulate fluid. For example, if the hydraulic circuit is a transmission cooling circuit, the operator starts the engine of the vehicle causing a circulation of fluid through the transmission cooling circuit.

Once the engine is started, fluid circulates through fluid exchange device 10 of FIG. 11 in a bypass mode as valve 145 is normally open unless energized. Therefore unless the ON-OFF switch of the fluid exchanger (not shown) is moved to its ON position, the fluid exchange device 10 remains in bypass mode characterized by the connection of conduits assemblies 231 and 233. In bypass mode, vane holder 5 of fluid pump assembly 1 remains stationary. Once the hydraulic circuit is operative to circulate fluid, the fluid exchange procedure may begin.

Float switch 141, which is a normally closed switch, is kept raised and activated as long as there is at least a minimum volume of fresh fluid 63 in fresh fluid reservoir assembly 55. If the level of fresh fluid 63 drops below a set minimum, float switch 141 opens and stops sending a signal to the integrated circuit board assembly which immediately turns off pump 129 and de-activates the solenoid of valve 145, placing the fluid exchanger in bypass mode of operation. If one of the normally open flow switches, flow switch 133 or 137 become closed by fluid flowing through either of them, that flow switch provides a signal to integrated circuit board assembly 149. Once integrated circuit board assembly 149 received signals from these sensors, it turns on pump motor 129 to spin in the correct direction based on which of the conduit assemblies 231 or 233 are receiving the pressurized fluid from the accessed hydraulic circuit and it energizes the solenoid of valve 145 to remove the bypass connection. FIG. 11 indicates a direction of fluid flow with arrows. These arrows indicate that the pressurized fluid from the accessed hydraulic circuit is flowing into conduit assembly 231, is blocked at checkvalve 206, flows through flow switch 133 that activates it. Because fluid flows through pressure transducer 165 and pressure transducer 169, both provide differentially varying signals to the integrated circuit board assembly 149 with the current of those signals increasing linearly in response to increases in the fluid pressure sensed by each.

The signal provided by flow switch 133 provides a signal only when there is fluid flow through it, in this case the flow of used fluid 65. Because pressure transducer 167 indicates a higher pressure than pressure transducer 169 and because flow switch 133 was activated, integrated circuit board assembly 149 energizes pump motor 129 to rotate vane holder 5 in a counter-clockwise direction. This result in fresh fluid 63 being pumped from fresh fluid reservoir assembly 55 through supply port 64, through supply conduit 119 to pass through check valve 117 while being blocked at check valve 115.

Fresh fluid 63 is pumped through the lower portion of left upper conduit 125, into fluid pump assembly 1 through port 23 and out of fluid pump assembly 1 through port 19, to enter conduit assembly 233 to pass through pressure transducer 169 and check valve 205 and then through female quick connect 97 to be deposited in the return side of the accessed hydraulic circuit.

As vane holder 5 of fluid pump assembly 1 rotates counterclockwise in response to the direction of the flow of used fluid 65 in the accessed hydraulic circuit, the used fluid 65 flowing through conduit assembly 231 flows through port 21 of fluid pump assembly 1 and is pumped through chamber 4 to pass out of fluid pump assembly 1 through port 25. Used fluid 65 then flows into upper right conduit 127, is blocked at check valve 115 and flows into priority valve assembly 109 through port 102, flowing through priority valve assembly 109 and out of middle port 108 through waste fluid conduit 121 and into waste receptacle 53.

The microprocessor contained on the integrated circuit board assembly 149 contains software instructions which keep increasing the rotation speed of pump motor 129 until the approximate difference between the one passing fresh fluid exceeds the one passing used fluid, in this instance that is by a factor of approximately 1.3 to 2.5 (but can be lesser or greater depending on the application but can be programmed to vary by the type of hydraulic circuit having its fluid exchanged). The speed of pump motor 129 is increased until that ratio is reached or until the pump reaches its maximum operating speed. If at any time the flow switch which is passing used fluid stops indicating flow, then the unit automatically reverts back to bypass mode and the current is removed from pump motor 129 which turns it off.

FIG. 12 is a schematic view of another fluid exchange device 10 which features a boost pump arranged to the fresh fluid supply conduit for exchanging the fluid of hydraulic circuits which include low flow circuits, such as certain automatic transmissions that circulate fluid in their cooling circuit at a relatively low flow, with an automatic fluid flow alignment device, and automatic bypass capability.

FIG. 12 includes a similar fresh fluid reservoir assembly 55 of FIG. 11 with float switch 144 with its set of leads 143, cover assembly 67 which is held in place by retainer clips 70 and 71, and with cap 69 which has vent 57. Assembly 55 includes supply port 64 that connected to one end of supply conduit assembly 177. Supply conduit 177 is also connected to check valve 178 and boost pump 179. Boost pump 179 may be a SHURFLO 8000 series diaphragm type pump operated by an AC power supply at 120 volts (not shown). Of course there are many other types of suitable pumps that can be used to pressurize the fresh fluid contained in fresh fluid reservoir assembly 55 and deliver it into fluid pump assembly 1. Boost pump 179 has a pair of leads 180. A compressed air powered pump could be substituted for boost pump 179.

A 50-micron screen (not shown) can be added to the supply port 64 or as a separate easily cleanable unit to the top end of supply conduit assembly 177 or to the top cover assembly 167 of fresh fluid reservoir assembly 55. Of course the specific size of the orifices the screen provides should be matched to the recommendations of the component parts the fresh fluid 63 will be flowing through and any specifications for the hydraulic circuit being serviced. A conduit assembly 192 is connected at one end to boost pump 179, at another end to a checkvalve 178, and at another end to a valve 181. Valve 181 has a set of leads 182 and is a two position, three-way electric solenoid operated valve which has a first or default position when its solenoid coil is un-energized and a second position when its solenoid coil is energized. The first or default position provides a fluid connection between conduit assembly 192 and conduit assembly 174, and the second energized position provides a fluid connection between conduit assembly 192 and conduit assembly 173.

Conduit assembly 173 is connected at one of its other two ends to valve 185 that has a pair of leads 186. Valve 185 is a two position, three-way electric solenoid operated valve which has a first or default position when its solenoid is un-energized. The first or default position provides a connection between conduit assembly 174 and waste fluid conduit 121. The second or energized position provides a connection between used fluid conduit 121 and a conduit assembly 173. Used fluid conduit 121 is arranged and positioned to deliver used fluid 65 into waste receptacle 53. Conduit assembly 173 is connected the one of its two other ends to port 25 of fluid pump assembly 1. Conduit assembly 174 is connected at its other end to port 23 of fluid pump assembly 1.

Conduit assembly 333 and conduit assembly 331 are comprised of flexible hydraulic hose. Conduit assembly 333 is connected to female quick connector 97 and conduit assembly 331 is connected to female quick connector 103. Conduit assembly 333 is connected at one of its other ends to port 19 of pump-mechanism 19 and at its other end to a bypass valve 175 that has a pair of leads 176. Bypass valve 175 is a two-position, two-way, normally-open solenoid operated valve. Conduit assembly 331 is connected at one of its ends to port 21 of fluid pump assembly 1, and has flow switch assembly 187 installed in-line.

The pair of leads 176 of bypass valve 175 are connected into and part of a male electrical plug 206 which is in turn connected into a female electrical plug 207 of integrated circuit board assembly 188. Both male electrical plug 306 and female electrical plug 307 are configured to receive wires connected to each of the electrical leads of valve 181, valve 185, bypass valve 175, and boost pump 179, and to in turn connect them to the various relay components installed on the integrated circuit board assembly 188 to provide current when certain sensor inputs are provided electrically to a male electrical plug 190 which connects to a female electrical plug 189 which is in turn connected to integrated circuit board assembly 188.

Flow switch assembly 187, installed in conduit assembly 331, has a set of four leads 207 which are connected into male electrical plug 190 along with the pair of leads 143 of float switch 144. Flow switch assembly 187 is a bi-directional, bi-indicating flow switch shown schematically in detail in FIG. 13 and shows finer detail of conduit assembly 331 and its in-line connections to valve body 196 of flow switch assembly 187.

Referring to FIG. 13, valve slide 194 is fitted within valve bore 210 of valve body 196 and is fitted with a spring off-center spring 201, preferably protruding approximately ¼ of the length of valve slide 194. Spring 210 cause valve slide 194 to move away from the ends of valve bore 210, thus insuring that valve slide 194 will move to properly respond to the direction of fluid flow in conduit assembly 331. Alternatively, check valves (not shown) can be installed to each of the pair of the separate upper branches of conduit assembly 231 which connect to port 202 and port 203 of valve body 196.

Arrows of FIG. 13 show the direction of fluid flowing into and through flow switch assembly 187 that in this instance as shown in FIG. 12 is from right to left. Spring 201 and the other spring at the end of valve slide 194 (not shown) have caused ports 202 and 203 to be blocked by slide. As the fluid from the accessed hydraulic circuit is pumped into conduit assembly 331 it passes through a port 199 of a valve plug 197 to enter the right side of valve bore 210 causing valve slide 194 to move to its left most position which opens port 202, which allows the fluid to flow out of valve bore 210 through port 202 to enter the left side of conduit assembly 231. If the direction of fluid flow in Conduit assembly 187 were from left to right the movement of valve slide 194 would be reversed and the flow pattern of the fluid would be reversed and the fluid would flow into a port 200 of the valve end 198.

Valve body 196 is fitted with two magnetic switches, a magnetic switch 208 and a magnetic switch 209 which together have a set of four leads 297. Valve slide 194 is fitted with a powerful permanent magnet, a magnet 195, which will trigger either of the magnetic switches 208 or 209 when it is placed in aligned proximity to either one of them. The set of four leads 207 is connected to male electrical switch 190 along with the set of pair of leads 144 of float switch 144.

Integrated circuit board assembly 188 is powered by an 120 volt, AC supply (not shown) via supply cord 153 connected at one end to integrated circuit board assembly 188. Electrical supply cord 153 is comprised of a hot wire, a neutral and a ground wire. Electrical supply cord 153 is connected at its other end to an electrical supply plug 155, which in turn is connected by the fluid exchanger operator to a 120 VAC electrical outlet.

FIG. 12 shows fluid 65 being pumped out of the hydraulic circuit being accessed and into conduit assembly 331. Initially this fluid will flow through bypass valve 175 because bypass valve 175 is a normally open valve until energized and the fluid exchanger of FIG. 12 would stay in bypass mode circulating fluid 65 between conduit assemblies 331 and 333 until the integrated circuit board assembly 188 activates bypass valve 175 to close it and turns on pump 179 and energizes either valve 181 or valve 185 depending on the direction of fluid flow through conduit assemblies 331 and 333.

Because left magnetic switch 209 of flow switch assembly 187 can be triggered by magnet 195, a relay circuit on the integrated circuit board assembly 188 closes thereby providing current to bypass valve 175, causing it to close. This results in used fluid 65 to be blocked at bypass valve 175 and to flow into port 21 of fluid pump assembly 1 where it then flows through chamber 4 of fluid pump assembly 1, and delivered through port 25 into conduit assembly 173.

When used fluid 65 flows through flow switch assembly 187, flow switch assembly 187 simultaneously triggers another relay circuit on integrated circuit board assembly 188 which energizes the solenoid of valve 185 to conduct fluid from conduit assembly 173 to waste fluid conduit 121. When energized, flow switch assembly 187 also triggers another relay on integrated simultaneously circuit board assembly 188 to energize the solenoid of valve 181 to conduct fluid from conduit assembly 192 to conduit assembly 173 when flow switch indicates during bypass that used fluid 65 is flowing in the opposite direction through conduit assembly 333. In its non-energized default position valve 185 connects conduit assembly 192 to conduit assembly 174.

During bypass mode, when the accessed hydraulic circuit is operative and pumps used fluid 65 through flow switch assembly 187, a logic circuit of a microprocessor on integrated circuit board assembly 188 (not shown but understood by those skilled in the art) receives a flow direction signal from flow switch assembly 187.

Before the microprocessor will process any signal from a start button to initiate a fluid exchange procedure, float switch 144 and one of the magnetic switches of flow switch assembly 207 must provide proper signals. If switch 144 and a magnetic switch are properly positioned, pressing the start button (not shown) will trigger a logic circuit in the microprocessor. The microprocessor and relays then activate either valve 181 or valve 185, depending on the direction of fluid flow in bypass between conduit assemblies 231 and 233, and also energize the solenoid of bypass valve 175 to close it.

When the start button was is engaged, three events occur. First, the microprocessor activates the solenoid of bypass valve 175 to close it. Second, the microprocessor activates valve 185 to pass used fluid 63 from conduit assembly 173 to waste fluid conduit 121. Third, the microprocessor activates boost pump 181 to pump fresh fluid 63 from supply port 64 of fresh fluid reservoir assembly 55 through supply conduit assembly 177 and into conduit assembly 192.

Check valve 178 will allow fluid to bypass boost pump 179 when it is off or fails to operate, and also blocks fluid from flowing in a bypass back through the valve which would prevent any fresh fluid to be pumped out of supply port 64.

The fresh fluid 63 then flows from conduit assembly 192 through valve 181 and into conduit assembly 174, but not through valve 185 because it is blocked due to valve 185 being energized. Fresh fluid 63 then flows into port 23 of fluid pump assembly 1, through chamber 2 and out of port 19 to flow into and through conduit assembly 333, to flow through female quick connector 97 to be delivered into the return side of the accessed hydraulic circuit.

The exchange of fresh fluid continues until the level of fresh fluid 63 is diminished to open float switch 144, resulting in float switch 144 providing an off signal to the microprocessor. The microprocessor then removes electrical current from all valves and the pump, thereby causing the fluid exchange device 10 to return to its bypass mode of operation wherein fluid provided by the accessed hydraulic circuit passes between conduit assemblies 231 and 233 through bypass valve 176 and is blocked at both valve 186 and 181.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. A fluid pump assembly comprising:

a pump housing;

a plurality of fluid conduits coupled to the pump housing and directing fluid into or out of the pump assembly;

a rotatable vane holder held within the pump housing, with a working chamber defined at one side of the vane holder and a pumping chamber defined on another side of the vane holder; and

a plurality of vanes slidably coupled to the vane holder, said vanes being biased outwardly from a vane holder center to engage a perimeter of the working chamber, and wherein a fluid introduced into the working chamber from one of the plurality of fluid conduits causes the vane holder and plurality of vanes to rotate and provide an expulsion of fluid out of the pumping chamber.

2. The fluid pump assembly of claim 1 wherein the vane holder includes a pair of generally planar surfaces matched to interior surfaces of the pump housing to seal the pumping chamber from the working chamber.

3. The fluid pump assembly of claim 1 wherein the plurality of vanes are biased under a spring force or fluid pressure exerted on an interior surface of the vanes.

4. The fluid pump assembly of claim 1 wherein one of the plurality of fluid conduits is in fluid communication with a hydraulic system of an automobile and receives used fluid during an exchange procedure.

5. The fluid pump assembly of claim 4 wherein another one of the plurality of fluid conduits is in fluid communication with the hydraulic system and delivers fresh fluid during the exchange procedure.

6. The fluid pump assembly of claim 5 wherein during the exchange procedure, a rate of used fluid flow through said conduit is approximately equal to a rate of fresh fluid flow through said another conduit.

7. The fluid pump assembly of claim 1 wherein some of said vanes are biased outwardly from a vane holder center to engage a perimeter of the pumping chamber.

8. The fluid pump assembly of claim 1 wherein the vane holder is generally cylindrical and wherein the vane holder is fitted into the housing so that portions of the vane holder sufficiently cooperate with portions of the pump housing to substantially seal fluid from flowing from the working chamber into the pumping chamber.

9. The fluid pump assembly of claim 1 wherein the plurality of vanes extend outwardly in radial fashion from a vane holder center.

10. The fluid pump assembly of claim 1 wherein the pump housing defines a generally elliptical cavity for receiving the vane holder.

11. The fluid pump assembly of claim 1 wherein the working chamber and pumping chamber contain substantially equal volumes of fluid so that during an exchange procedure a used fluid rate is substantially matched to a fresh fluid rate.

12. The fluid pump assembly of claim 1 wherein the vane holder is coupled to a electric motor, said electric motor providing a rotating force during an exchange procedure tending to increase rotation of the vane holder and facilitate a faster fluid exchange.

13. A fluid pump assembly comprising:

a rotating vane holder held within a pump housing, said vane holder carrying a plurality of vanes which are outwardly biased to engage interior wall surfaces of the pump housing, said plurality of vanes sliding in and out of the vane holder as said vane holder rotates; and

a working chamber defined on one side of the vane holder, wherein a fluid introduced into the working chamber from a fluid conduit coupled to the pump housing causes rotation of the vane holder and expulsion of the fluid out of the fluid pump assembly.

14. The fluid pump assembly of claim 13 further comprising:

a fresh fluid conduit in fluid communication with the pump housing and receiving a fresh fluid expelled out of a pumping chamber.

15. The fluid pump assembly of claim 13 wherein the vane holder includes surfaces matched to cooperate with interior surfaces of the pump housing to seal fluid flow from the working chamber into a pumping chamber.

16. The fluid pump assembly of claim 13 wherein the plurality of vanes are biased under a spring force or fluid pressure exerted on an interior surface of the vanes.

17. The fluid pump assembly of claim 13 wherein one of the plurality of fluid conduits is in fluid communication with a hydraulic system of an automobile and receives used fluid during an exchange procedure.

18. The fluid pump assembly of claim 17 wherein another one of the plurality of fluid conduits is in fluid communication with the hydraulic system to deliver fresh fluid to the hydraulic system during the exchange procedure.

19. The fluid pump assembly of claim 18 wherein during the exchange procedure, a rate of used fluid flow through said conduit is approximately equal to a rate of fresh fluid flow through said another conduit.

20. The fluid pump assembly of claim 13 wherein some of said vanes are biased outwardly from a vane holder center to engage a perimeter of the pumping chamber.

21. The fluid pump assembly of claim 13 wherein the vane holder is generally cylindrical and wherein the vane holder is fitted into the housing so that portions of the vane holder sufficiently cooperate with portions of the pump housing to substantially seal fluid from flowing from the working chamber into the pumping chamber.

22. The fluid pump assembly of claim 13 wherein the plurality of vanes extend outwardly in radial fashion generally from a vane holder center.

23. The fluid pump assembly of claim 13 wherein the pump housing defines a generally elliptical cavity for receiving the vane holder.

24. The fluid pump assembly of claim 13 wherein the working chamber and pumping chamber contain substantially equal volumes of fluid so that during an exchange procedure a used fluid rate is substantially matched to a fresh fluid rate.

25. A fluid pump assembly comprising:

a rotating vane holder held within a pump housing, said vane holder carrying a plurality of vanes which are outwardly biased to engage interior wall surfaces of the pump housing, said plurality of vanes sliding in and out of the vane holder as said vane holder rotates;

a used fluid conduit positioned at one end to a hydraulic system, and during an exchange procedure said used fluid conduit delivers a used fluid from the hydraulic system into the pump housing;

a fresh fluid conduit positioned at one end to the hydraulic system, and during the exchange procedure said fresh fluid conduit delivers a fresh fluid from the pump housing into the hydraulic system; and

a working chamber defined on one side of the vane holder, wherein used fluid from the used fluid conduit engages some of the plurality of vanes causing rotation of the vane holder and expulsion of a fresh fluid out of the fluid pump assembly and into said fresh fluid conduit.

26. The fluid pump assembly of claim 25 wherein a pumping chamber and said working chamber are generally equal in volume.

27. The fluid pump assembly of claim 26 wherein the hydraulic system is an automatic transmission or powered steering system of a vehicle.

28. The fluid pump assembly of claim 27 wherein the used fluid conduit receives used transmission fluid pressurized by an automatic transmission pump on the vehicle during a transmission fluid exchange procedure.

29. The fluid pump assembly of claim 27 wherein the used fluid conduit receives used power steering fluid pressurized by a power steering pump on the vehicle during a power steering fluid exchange procedure.

30. The fluid pump assembly of claim 25 wherein said plurality of vanes are biased under a spring force or a fluid force tending to bias said vanes outwardly.