US20080050262A1

US20080050262A1 - Rotary pump having a valve rotor and one or more vane rotors and methods for pumping fluids

Info

Publication number: US20080050262A1
Application number: US11/467,055
Authority: US
Inventors: Sam J. Jacobsen; Melvin F. Huber; Craig H. Melter
Original assignee: Individual
Current assignee: JACOBSEN SAM J
Priority date: 2006-08-24
Filing date: 2006-08-24
Publication date: 2008-02-28
Also published as: WO2008024987A3; WO2008024987A2

Abstract

A rotary pump includes a valve rotor and one or more vane rotors positioned around it. Each vane rotor has a vane that engages a slot in the valve rotor as the vane rotor rotates. A housing around the valve rotor and the vane rotor(s) defines a generally constant-radius pump space around each vane rotor and includes inlet and discharge openings associated with each vane rotor. As each vane rotor rotates within the housing, its vane sealingly interacts with the housing, while that vane rotor sealingly interacts with the valve rotor. The vane interacts with the channel, allowing the vane to move past the valve rotor. As the vane rotor rotates, the vane enters the pump space to divide the pump space into at least inlet and discharge portions, while fluid within the discharge portion is discharged or compressed and additional fluid is drawn into the inlet portion.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention is directed to rotary pumps having a valve rotor, one or more vane rotors and methods for pumping fluids using rotary pumps having a valve rotor and one or more vane rotors.
2. Related Art
Rotary external or internal tooth, vane and piston pumps are commonly used to compress gases and/or to pump fluids in fluid systems. These types of pumps typically comprise an inlet opening, one or more rotating members and an outlet or discharge opening. The internal and external tooth gear pumps fill the void between teeth with fluid and/or gas at the inlet and, by rotating the teeth, deliver the fluid and/or gas to a transport or displacement area that is provided between the inlet and the discharge. Rotating the teeth further delivers the fluid and/or gas to a discharge area. The gear teeth then mesh together to seal the discharge area from the inlet. This type of pump has a low displacement for the overall volume occupied by the pump. This occurs mainly due to the number of teeth required. The rotary speed of this type of pump is limited, due to the time required to fill the areas between the teeth with the fluid flowing through the inlet.
The rotary vane pump has one or two lobes with movable vanes. The vane rotor and the vanes rotate inside a housing. The inside surface of the housing of each lobe defines a vane cam surface for the vane rotor. As each vane rotor rotates, the vanes follow the internal vane cam surface of the housing. The interaction of the vanes with the vane cam surface defines at least an inlet sector, a transport or displacement sector, and a discharge sector. In particular, each pair of adjacent vanes defines a separate internal volume within the vane pump. In a conventional vane pump, as the vane rotor makes a complete rotation, each separate internal volume between adjacent vanes in turn is the inlet sector, the transport or displacement sector, the discharge sector and a return sector.
A particular internal volume is an inlet sector when its leading vane passes by one or more inlet openings, such that the internal volume is exposed to the one or more inlet openings that allow the fluid (to be pumped) to flow into and at least partially fill that internal volume. That internal volume becomes a transport or displacement sector when its trailing vane passes by the one or more inlet openings and remains a transport or displacement sector until its leading vane passes by one or more discharge openings. That internal volume becomes a discharge sector when its leading vane passes by the one or more discharge opening. That internal volume becomes a return sector when its trailing vane passes by the one or more discharge openings and then remains the return sector until its leading vane once again passes by the one or more inlet openings.
In conventional vane pumps, the distance between the surface of the vane rotor and the vane cam surface varies substantially at least where an internal volume is an inlet sector or a discharge sector. At such times, the vanes reciprocatively move radially relative to the vane rotor. As a consequence, the volume of the inlet sector increases as a function of the rotational movement of the vane rotor and the vanes defining that inlet sector, as well as a function of the increasing distances between the surface of the vane rotor and the vane cam surface seen by those vanes. Similarly, the volume of the discharge sector decreases as a function of the rotational movement of the vane rotor and the vanes defining that discharge sector, as well as a function of the decreasing distances between the surface of the vane rotor and the vane cam surface seen by those vanes.
The angular distance or extent of each internal volume around the vane rotor depends on the number of vanes provided around the vane rotor. In conventional vane pumps, there are at least 4 vanes such that each internal volume extends 90° around the vane rotor. Thus, for a 4-vane vane pump, the average displacement area of each internal volume is 90° of rotation. Of course, as the vane rotor is provided with more vanes, the maximum displacement of each internal volume will decrease proportionally. In such vane pumps, the vane tip is subjected to tip stress as the vane rotor rotates.
The maximum volume of the inlet sector and the flow rate of the fluid into the inlet sector determines how long it takes to completely fill the inlet sector, i.e., the inlet fill time. The inlet fill time determines the maximum vane tip speed that can be achieved if the inlet sector is to be completely filled before the trailing vane pauses by the one or more inlet openings. Put differently, the time it takes to fill the inlet sector, i.e., the inlet fill time, along with the available inlet pressure, determines the maximum vane tip speed of the vane pump. As more vanes are used, the fill time increases but the available displacement volume decreases.
As indicated above, the radial distance between the vane rotor and the vane cam surface typically varies over the 360° of rotation of the vane rotor. However, it can be substantially constant over a given amount of rotation. For example, the portion of the vane cam surface that is associated with the displacement sector cam has a substantially constant radial distance from the vane rotor. The discharge pressure pulsations will tend to be less with such a constant-radius displacement sector and fewer vanes and will tend to be more with a varying-radius displacement sector.
In summary, such vane pumps have movable vanes that translate relative to the vane rotor so that the tips of the vanes closely follow the inner vane cam surface of the housing to effectively divide the space between the vane cam surface of the housing and the outer surface of the vane rotor into one or more internal volumes. As the vane rotor rotates and the vanes move radially relative to the vane rotor to closely follow the vane cam surface of the housing, the fluid to be pumped enters the inlet sector through the inlet opening. The fluid is transported or displaced to the displacement sector, and then to the discharge sector, where rotation of the vane rotor and the interaction of the movable vane with the vane rotor and the vane cam surface of the housing forces the fluid or gas out of the pump space through the outlet or discharge opening. U.S. Pat. Nos. 6,877,969; 7,014,439; and 7,048,526 disclose typical vane pumps.
The piston type rotary pump has a piston and rod assembly driven with a crank shaft that converts rotary motion to reciprocating motion of the piston within a pump space. The housing for the piston and crank assembly incorporates inlet and discharge valve(s). As the piston moves away from the valves, a lower pressure within the pump space is created, thus filling the pump space with fluid and/or gas through the inlet valve. The fluid and/or gas is then discharged from the pump space through the discharge valve as the piston moves towards the valves. This type of pump has a high volumetric efficiency but its speed and displacement are limited due to valve area availability, and it is speed limited due to mechanical limits when converting rotary motion to reciprocating motion. Piston-type rotary pumps require timing gears to open and close the valves at the appropriate times. In contrast, gear and vane pumps do not require timing gears.
In gear pumps, the rotating members are shaped with fixed teeth, lobes or the like that mate or intermesh in a manner similar to the way in which gear teeth mate or intermesh. The housing containing the two rotating members typically has two opposing semi-circular lobes attached by two parallel walls, with the inlet opening in one of the parallel walls and the outlet or discharge opening in the other of the parallel walls. In contrast, rotary vane pumps include a circular or elliptical housing having an inlet opening and an outlet opening and a vane rotor whose axis of rotation is offset from the axis of the housing.

SUMMARY OF THE DISCLOSED EMBODIMENTS

This invention provides rotary pumps and methods for pumping fluids comprising one or more vane rotors that each have one or more vanes that divide a pump space into an inlet space and a discharge space.
This invention separately provides rotary pumps and methods for pumping fluids comprising one or more vane rotors that each have one or more vanes that divide a pump space into an inlet space, a displacement space, and a discharge space.
This invention separately provides rotary pumps and methods for pumping fluids comprising at least one vane rotor that each has a substantially large displacement volume.
This invention separately provides rotary pumps and methods for pumping fluids comprising one or more vane rotors that each have a vane that interacts with or engages at least one slot formed in a valve rotor as the valve rotor and the one or more vane rotors rotate relative to each other.
This invention separately provides rotary pumps and methods for pumping fluids where each vane of the one or more vane rotors interacts with or engages a slot in the valve rotor outside of a pump portion of the rotation of the rotary mechanisms.
This invention separately provides rotary pumps and methods for pumping fluids where each vane forms an effective seal with a rotor housing portion of a housing structure that surrounds the one or more vane rotors and the valve rotor.
This invention separately provides rotary pumps and methods for pumping fluids where each vane rotor has at least a relatively large displacement rotation, relative to conventional vane pumps, for every rotation of the valve rotor.
This invention separately provides rotary pumps and methods for pumping fluids where each vane rotor has at least a relatively large displacement rotation and uses a check valve in the discharge path.
This invention separately provides rotary pumps and methods for pumping fluids where each vane rotor has vanes in the vane rotor and sufficient slots in the valve rotor and no check valve in the discharge housing.
This invention separately provides a rotary pump that can be operated at high rotational speeds.
This invention separately provides rotary pumps and methods for pumping fluids comprising one or more vane rotors that have one or more substantially fixed vanes.
This invention separately provides rotary pumps and methods for pumping fluids comprising a vane rotor and a corresponding housing where the surface of the vane rotor is located a substantially constant distance from the inner surface of the housing.
This invention separately provides rotary pumps and methods for pumping fluids comprising a substantially circular vane rotor located within a substantially circular pump space substantially at a center point of the substantially circular pump space.
This invention separately provides rotary pumps and methods for pumping fluids where the rotary pump has a large displacement for volume occupied.
This invention separately provides rotary pumps and methods for pumping fluids where the rotary pump can be operated in an oil-less and/or oil-free mode.
This invention separately provides rotary pumps and methods for pumping fluids where the rotary pump does not have one or more of an offset vane rotor, a vane cam surface, reciprocating vanes or high tip stress.
This invention separately provides rotary pumps and methods for pumping fluids where the rotary pump has no reciprocating parts during the pumping cycle.
This invention separately provides rotary pumps and methods for pumping fluids where a valve rotor has at least one developed slot designed to accept, and create an effective seal with, a vane of a vane rotor as the vane rotates from a discharge position to an inlet position.
In various exemplary embodiments of rotary pumps and methods for pumping fluids according to this invention, a rotary pump includes a valve rotor and one or more rotationally-coordinated vane rotors positioned around its circumference. A housing having a corresponding number of rotor housing portions is placed around the valve rotor and the one or more vane rotors to define a pump volume or space around each vane rotor. Each vane rotor has one or more vanes that separate the pump volume or space around that vane rotor into two or more portions. Each vane of the vane rotor is able to rotate past the valve rotor. In various exemplary embodiments, each vane interacts with and/or engages with the housing and an appropriately-shaped slot or recess in the valve rotor as the valve rotor and/or the vane rotor(s) are rotatingly driven. In various exemplary embodiments, at least some of the rotors are kept in sequence with timing gears.
In various exemplary embodiments, at a location near an upstream end of the pump volume or space around each vane rotor, the housing includes one or more inlet openings into that pump volume or space. Similarly, near the downstream end of each pump volume or space of each vane rotor, the housing includes at least one discharge outlet from the pump volume or space.
In various exemplary embodiments, one or more vane rotors, the one or more slots in the valve rotor and the corresponding one or more rotor housing portions of the housing are distributed around the circumference of the valve rotor. In various exemplary embodiments, one vane rotor is located around the outside of the circumference of the valve rotor, along with at least one slot in the valve rotor and a corresponding rotor housing portion in the housing. In various other exemplary embodiments, any number of vane rotors, such as, 2, 3, 4 or more vane rotors, can be distributed around the outside of the circumference of the valve rotor, with an appropriate number of slots and rotor housing portions provided in the housing.
In various exemplary embodiments, as the vane rotor rotates within the rotor housing portion of the housing, each vane in turn makes an effective seal with the inner surface of the rotor housing portion of the housing. In various exemplary embodiments, at the same time, the vane rotor and the valve rotor also make an effective seal at the point where their respective surfaces interact or closely approach each other. At specific portions of the rotational positions of the vane rotors, each vane is downstream from the one or more discharge openings and upstream of the one or more inlet openings, such that it is outside of a pump region of the housing and the vane rotor. In various exemplary embodiments, that vane, while outside the pump region of the rotary mechanism, interacts with or engages a slot or channel in the valve rotor to allow that vane to enter the pump region by moving to a position that is rotationally upstream of the inlet opening. In various exemplary embodiments, because the vane interacts with the slot in a region that is outside of the pump volume or space of the rotary mechanism, the vane does not need to create a seal with the surface of the slot formed in the valve rotor.
In various exemplary embodiments, each vane rotor makes at least one pump displacement discharge for every revolution of the vane rotor. In various exemplary embodiments, the valve rotor is timed to provide an effective seal with each vane and with each vane rotor as it rotates. In various exemplary embodiments, the valve rotor acts as a rotary valve by interacting with the vane(s) of the vane rotor as the vane rotor rotates. In various exemplary embodiments, each slot in the valve rotor accepts the vane(s) of the vane rotor. In various exemplary embodiments, the discharge is separated from the inlet by the interaction of the valve rotor outside diameter with the vane rotor outside diameter. In various exemplary embodiments, the vane of the vane rotor is at a constant radius position throughout the pumping cycle. In various exemplary embodiments, the rotary pump can be operated in an oil-free or oil-less mode. In various exemplary embodiments, the rotary pump has a large displacement for volume occupied.
These and other features and advantages of various exemplary embodiments of multi-rotor rotary pumps and methods for pumping fluids according to this invention are described in, or apparent from, the following detailed description.

BRIEF DESCRIPTION OF DRAWINGS

Various exemplary embodiments of rotary vane pumps and methods for pumping fluids according to this invention will be described in detail, with reference to the following figures, wherein:

FIG. 1 is a perspective view of a first exemplary embodiment of a rotary pump according to this invention;

FIG. 2 is a plan view of one end of a first exemplary embodiment of the valve rotor of the rotary pump shown in FIG. 1;

FIG. 3 is a side perspective view of the first exemplary embodiment of the valve rotor shown in FIG. 2;

FIG. 4 is a side perspective view of a first exemplary embodiment of a vane rotor of the rotary pump shown in FIG. 1;

FIG. 5 is a plan view showing in greater detail a first exemplary embodiment of a rotary pump according to this invention that includes the valve rotor of FIGS. 2 and 3 and the vane rotor of FIG. 4, where the vane extends into the slot of the valve rotor;

FIG. 6 is a plan view of the rotary pump of FIG. 5 after the vane rotor has been rotated partially through the discharge portion of the pumping cycle;

FIG. 7 is a plan view of the rotary pump of FIG. 5 during a return portion of the pumping cycle, where the vane rotor has rotated to a position where the vane is entering the slot and just before the rotary pump returns to the position shown in FIG. 5;

FIG. 8 is a plan view showing in greater detail a second exemplary embodiment of a rotary pump according to this invention, where the vane rotor has two vanes and the valve rotor has a corresponding set of slots, with a first vane meshed with one of the slots of the valve rotor during an inlet portion of the pumping cycle for the first vane;

FIG. 9 is a plan view of the rotary pump of FIG. 8 after the vane rotor has rotated to a position just after the end of the inlet portion and just after the beginning of a transport portion for the pumping cycle of the first vane;

FIG. 10 is a plan view showing in greater detail a third exemplary embodiment of a rotary pump according to this invention, including a vane rotor having three vanes and a valve rotor having a corresponding set of slots, with a first vane meshed with one of the slots of the valve rotor during an inlet portion of the pumping cycle of the first vane;

FIG. 11 is a plan view of the rotary pump of FIG. 10 after the vane rotor has been rotated to a position after the end of the inlet portion and at the beginning of the transport portion of the pumping cycle of the first vane;

FIG. 12 is a side perspective view of a second exemplary embodiment of a valve rotor according to this invention;

FIG. 13 is a side perspective view of a second exemplary embodiment of a vane rotor according to this invention;

FIG. 14 is a plan view showing in greater detail a second exemplary embodiment of a rotary pump according to this invention that includes the valve rotor of FIG. 12 and the vane rotor of FIG. 13, where the vane extends into the slot of the valve rotor.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following detailed description of various embodiments of rotary vane pumps according to this invention will be described with the respect to a rotary vane pump that is driven via the vane rotor (or possibly by the valve rotor) and that outputs pumped fluid. However, it should be appreciated that the only significant difference between a rotary pump and a rotary motor is whether the fluid is pumped by the rotary pump such that energy enters the rotary pump via one of the rotors and exits via the pumped fluid or the fluid drives the rotary motor such that energy enters the rotary vane motor via the fluid and exits via one of the rotors. In general, whether used as a rotary pump or a rotary motor, the devices described below will generally operate under the same basic principals. Thus, it should be appreciated that the term “rotary pump” is intended to encompass various uses of devices according to this invention.
Likewise, it should be appreciated that the term “pump” encompasses not only pumping liquids, but also compressing compressible fluids, such as gases. According, while the following detailed description of exemplary embodiments refers to rotary pumps, it should be appreciated that when the various exemplary embodiments of the devices described below are used to compress a compressible fluid, the term “rotary compressor” may be more appropriate. Thus, it should be appreciated that devices according to this invention can be used as air compressors, air pumps, generic fluid compressors, generic fluid pumps, air motors, pneumatic motors, hydraulic motors, generic fluid motors, superchargers and the like. It should also be appreciated that, in exemplary embodiments that use multiple vane rotors, since the vane rotors are generally fluidly isolated from each other, one or more of the vane rotors can be used as motor devices, while one or more other ones of the vane rotors can be used as pump devices, to transfer energy from a first input fluid to a second output fluid, such as in a supercharger or turbocharger. In this case, the valve rotor is not necessarily used to either input energy to, or output energy from, the rotary pump.
FIG. 1 shows a first exemplary embodiment of a rotary pump 100 according to this invention. As shown in FIG. 1, the rotary pump 100 includes a valve rotor 110, a peripherally-located vane rotor 120 and a housing 130 that encloses the valve rotor 110 and the peripherally-located vane rotor 120. In particular, the rotary pump 100 shown in FIG. 1 can be provided with at least one vane rotor assembly 102, where each vane rotor assembly 102 contains one vane rotor 120 and associated portions of the housing 130.
As shown in FIG. 1, the valve rotor 110 includes a first support shaft 112 and a number of slots or channels 116. Each peripherally-located vane rotor 120 includes a rotor body 121, a first support shaft 122, and a vane 126 that extends away from the surface of the rotor body 121. As shown in FIG. 1, when the vane rotor 120 is at a predetermined position relative to the valve rotor 110, the vane 126 lies within the slot or channel 116.
As shown in FIG. 1, the housing 130 extends around the vane rotor 120 and the valve rotor 110 to enclose them along their length. In particular, as shown in FIG. 1, the housing 130 is spaced away from the peripherally-located vane rotor 120 to form a pump volume or space 132 surrounding that vane rotor 120. As the vane rotor 120 rotates, the vane 126 rotates into the pump space 132 and effectively divides the pump space 132 into at least a discharge region or space 132 b and an inlet region or space 132 a (shown in FIGS. 6 and 7). As shown in FIG. 1, the housing 130 includes a rotor housing portion 134 around the vane rotor 120 and one or more connecting or support portions 136 that surround the valve rotor 110 and are connected to the rotor housing portion 134.
As shown in FIG. 1, a pair of timing gears 118 and 128 are located at one axial end of the valve and vane rotors 110 and 120. In particular, the first timing gear 118 is located at one axial end of the valve rotor 110. The first timing gear 118 can be contiguous with the valve rotor 110 or can be a separate element that is adjacent to or spaced from that axial end of the valve rotor 110. Typically, the first timing gear 118 will be located, either integrally with or merely attached to, around one of the support shafts 112 et al. that extend axially from the valve rotor 110. Similarly, the second timing gear 128 is located at one axial end of the vane rotor 120. The second timing gear 128 can be contiguous with the vane rotor 120 or can be a separate element that is adjacent to or spaced from that axial end of the vane rotor 120. Typically, the second timing gear will be located, either integrally with or merely attached to, around one of the support shafts 122 et al. that extend axially from the vane rotor 120. It should be appreciated that, if the drive force and the load are not both on the vane rotor 120, the timing gears 118 and 128 can also be drive gears. In this case, the drive/timing gears 118 and 128 would generally be more robust and heavy than if the timing gears 118 and 128 are simply used as timing gears. Although they are not shown, an end cap is placed at each axial end of the housing 130 to fully enclose the valve and vane rotors 110 and 120 and possibly the timing gears 118 and 128.
As shown in FIG. 1, at or near a “front” or “upstream” circumferential end of the rotor housing portion 134, one or more inlet holes or ports 150 extend through the thickness of the rotor housing portion 134, and/or the connecting portion 136, to connect a supply of fluid to be pumped and/or an ambient atmosphere to the pump space 132. In particular, the one or more inlet holes 150 act as inlet ports that allow the rotary pump 100 to draw supply fluids and/or an ambient fluid into the pump space 132 in back of the vane 126 as the vane 126 is rotated from the front or upstream end of the rotor housing portion 134 to a “back” or “downstream” end of the rotor housing portion 134. Thus, the one or more inlet ports 150 allow gases and/or other fluids to be drawn from the fluid supply source and/or from the ambient atmosphere through the one or more inlet ports 150 and into the inlet space created as the vane 126 rotates from the front or upstream end to the back or downstream end of the rotor housing portion 134. In addition, although not shown in FIG. 1, the rotor housing portion 134 and/or the connecting portions 136 includes one or more discharge ports 160 (shown in FIG. 5).
FIG. 2 is an end plan view of one exemplary embodiment of the valve rotor 110 according to this invention. FIG. 3 is a side perspective view of the valve rotor 110 shown in FIGS. 1 and 2. As shown in FIGS. 1-3, the valve rotor 110 includes the first support shaft 112, as well as a second support shaft 114. The first and second support shafts 112 and 114 fit into channels or passages formed in the end plates that are attached to the ends of the housing 130. The first and second support shafts 112 and 114 allow the valve rotor 110 to be rotatably supported by the end plates. In various exemplary embodiments, at least one of the first and second support shafts 112 and 114 will extend through the corresponding end plate to allow the valve rotor 110 to be directly or indirectly connected to a drive source that is able to rotatingly drive the valve rotor 110 and the vane rotor 120. It should be appreciated that the timing gear 118 is omitted from FIGS. 2 and 3 for clarity.
As shown in FIG. 2, the valve rotor 110 is a generally circular cylindrical element having a centrally-located first support shaft 112 and one or more slots or channels 116. As shown in FIG. 2, in various exemplary embodiments, each of the one or more slots or channels 116 is developed, i.e., has a shape that is defined by the shape of the vane 126 that interacts with the slot or channel 116, to allow the vane 126 to pass through the slot or channel 116 while maintaining a close clearance seal or a contact seal with the developed slot or channel 116. This developed shape of the slot or channel 116 can be, for example, similar to an involute profile. In particular, in such exemplary embodiments, the shape of the developed slot or channel 116 is such that a very tight clearance, such as a gap on the order of about 0.005 inch or less, is provided between the surface of the vane 126 and the surface of the developed slot or channel 116 as the vane 126 passes through the developed slot or channel 116. In various other exemplary embodiments, no clearance is provided between the surface of the developed slot or channel 116 and the surface of the vane 126 such that a contact seal is provided.
In some other exemplary embodiments, the shape of the one or more slots or channels 116 merely sufficient to allow the vane 126 or the like to transition from the downstream side of the pump space 132 and the valve rotor 110 to the upstream side of the pump space 132 and the valve rotor 110. In such exemplary embodiments, this undeveloped shape for the slot or channel 116 may allow a small amount of the fluid being pumped to flow from the discharge space 132 b to the inlet space 132 a, thus reducing the efficiency of the rotary pump 100. It should be appreciated that the developed slot or channel 116, while reducing the amount of pumped fluid that is able to pass through the developed slot or channel 116 from the discharge space 132 b to the inlet space 132 a, does not necessarily eliminate such losses or leaks.
In various exemplary embodiments, the one or more slots or channels 116 can have rounded corners and a floor that is generally a portion of an arc having a center point at the axis of the circular cylindrical valve rotor 110 but at a reduced radius. It should be appreciated that this shape is useful in that it allows a very close mating interaction to occur with the outermost portion of the surface of the vane 126. In some exemplary embodiments, the slot or channel 116 also allows the vane 126 to move from the back or downstream end of the pump space 132 to the front or upstream end of the pump space 132 without inappropriately contacting the valve rotor 110 or the sidewalls of the housing 130. It should be appreciated that the vane 126 is desirably able to smoothly transition from the pump space 132 into the slot or channel 116 and from the slot or channel 116 into the pump space 132. It should be appreciated that the slot or channel 116 and/or the vane 126 can have any appropriate shape that allows the vane 126 to smoothly transition from the pump space 132 into the slot or channel 116 and from the slot or channel 116 into the pump space 132, and in various exemplary embodiments, allows a sufficiently small gap to be established between the vane 126 and the inner surface of the rotor housing portion 134.
FIG. 4 is a side perspective view of one exemplary embodiment of the vane rotor 120. As shown in FIG. 4, the vane rotor 120 includes the rotor body 121, while the first support shaft 122 and a second support shaft 124 extend axially from the rotor body 121. In the exemplary embodiment shown in FIG. 4, the vane 126 extends radially from the surface of the rotor body 121. In various exemplary embodiments, the vane 126 is U-shaped or rectangularly-shaped, although it can have any appropriate shape. It should be appreciated that the timing gear 128 is omitted from FIG. 4 for clarity.
Like the first and second support shafts 112 and/or 114 of the valve rotor 110, in various exemplary embodiments, at least one of the first and second support shafts 122 and/or 124 can extend through the corresponding end plate to allow the vane rotor to be directly or indirectly connected to a drive source that is able to drive the vane rotor 120 and the valve rotor 110. As outlined above, the first or second support shaft 112 or 114 also allows timing and/or drive gears to be provided to that first and/or second support shaft 112 and/or 114. The timing and/or drive gears are at least used to maintain the proper rotational positions between the vane rotor 120 and the valve rotor 110. As outlined above, the timing and/or drive gears can also be used to transmit the rotational energy to the valve rotor 110 from the vane rotor 120 to rotatingly drive the valve rotor 110 via the vane rotor 120, or vice versa.
It should be appreciated that the pump load is primarily, if not substantially completely, on the vane rotors 120, with little to no pump load on the valve rotor 110. As a consequence, it may be more appropriate to directly drive a vane rotor 120 rather than the valve rotor 110. When the vane rotor 120 is driven by applying an external rotational force on one of the first or second support shafts 122 or 124 of the vane rotor 120, a relatively small and light-weight set of gears between the vane rotor 120 and the valve rotor 110 cane be used to drive the unloaded valve rotor 110.
A relatively thick and large gear set may be desirable in two situations: where there are two or more vane rotors 120 to be drive, and/or where the valve rotor 110 is to be driven. In either case, the drive torque, to be applied to the vane rotors 120 that are not directly driven to rotate those vane rotors 120 against the pump load, must be transmitted through the gear set from either the valve rotor 110 or a directly-driven one of the vane rotors 120. Accordingly, to transmit the drive torque to rotate the vane rotors 120 against the pump load, the gears must be sufficiently robust to withstand the drive torque and the pump load. Finally, a more robust set of gears may be desirable when using the rotary pump 100 as an air or fluid motor. This would be useful when the valve rotor 110, rather than the vane rotors 120, is to be driven against an external load, such as a magnetic field when using the rotary pump 100 as a generator. In any case, the drive gears, regardless of their size and robustness, are also usable as timing gears to maintain the vane rotors 120 in the proper spatial relationship with the slots or channels 116 in the valve rotor 110.
It should be appreciated that, in various exemplary embodiments, the drive/timing gears can also be housed within, rather than outside of, the housing 130. In that case, the first and/or second support shafts 112 and/or 114 (or the first and/or second support shafts 122 and/or 124) may not extend through the end plate. Additionally, as indicated above, in some exemplary embodiments, the timing gears may be provided integrally with the valve rotor 110 and/or the vane rotor 120.
FIG. 5 shows in greater detail a plan end view of a first exemplary embodiment of a vane rotor 120 having a single vane 126, the associated surrounding rotor housing portion 134 and adjacent connecting portions 136 and an adjacent portion of the valve rotor 110. In particular, in FIG. 5, the vane rotor 120 is positioned relative to the valve rotor 110 at a zero degree (0°) position. In this zero degree (0°) position, the vane 126 faces the valve rotor 110 and is located within a central portion of the slot or channel 116.
FIG. 5 also shows a discharge port 160 and a check valve, reed valve, or other one-way valve structure 164. FIG. 5 further shows that, if one is included, the check valve, reed valve, or other one-way valve structure 164 is closed, preventing any back-flow of pumped and/or compressed gases and/or fluids from a downstream outlet passage, receiving tube, manifold or the like back through the discharge port 160, into the pump space 132. It should be appreciated that, in the single-vane embodiment shown in FIGS. 1-7, while the vane 126 can form an effective seal with the slot or channel 116, it is not necessary that an effective seal be formed between the vane 126 and the slot or channel 116.
A reservoir or accumulator can be attached to each discharge port 160. In various exemplary embodiments, each discharge port 160 allows the pumped fluid or compressed gas to freely exit from the discharge space 132 b as the vane 126 is rotated towards the one or more discharge ports 160. In other various exemplary embodiments, each discharge port 160 includes the check valve, reed valve, or other one-way valve structure 164 that allows the pumped fluid in the discharge space 132 b to leave the discharge space 132 b, while preventing any pumped fluid or any other fluid from back-flowing through the one or more discharge ports 160 into the pump space 132. It should be appreciated that, when the rotary pump 100 is used to compress air or other gases, the accumulator or reservoir that the one or more discharge ports 160 can be connected to can include a combustion chamber, a compressed air or gas tank, such as a scuba tank or the like, a pressure suit, a pneumatic tool or the like, or any other or generic pumped fluid reservoir, accumulator, receiving passage or device.
It should also be appreciated that, in various exemplary embodiments, if the thickness of the rotor housing portion 134 and/or the connecting portion 136 is insufficient, the check valve, reed valve, or other one-way valve structure 164 can be located within a discharge tube directly or indirectly connected to the discharge port 160, rather than being located within the discharge port 160 itself. It should also be appreciated that, if the rotary pump 100 is used to compress something other than the ambient atmosphere in which it is placed, rather than having open inlet ports 150, as shown FIG. 1, a supply tube or manifold can be attached to the inlet ports 150 to allow a supply of a desired gas, a desired liquid, gas and/or liquid composition, or the like to be provided to the rotary pump 100.
As the vane rotor 120 rotates clockwise, the timing/drive gears 118 and/or 128 cause the valve rotor 110 to rotate counter-clockwise. As the vane rotor 120, and thus the vane 126, rotates clockwise, the vane 126 moves toward and then past the inlet port 150. In response, the vane 126 clears the slot or channel 116 in the valve rotor 110, and enters the adjacent pump space 132. This position is shown in FIG. 6.
At least about the same time, the slot or channel 116 is rotated past the vane rotor 120, so that the surface of the vane rotor 120 is now adjacent to or in contact with the surface of the valve rotor 110. That is, the outer surface of the valve rotor 110, having the radius r₁, sealingly interacts with the outer surface of the vane rotor 120, having the radius r₂. Accordingly, an effective seal is created both at the interface point between the vane rotor 120 and the valve rotor 110 and at the interface between the outer surface of the vane 126 and the inner surface of the rotor housing portion 134.
It should be appreciated that, the surface of the vane rotor 120 and the surface of the valve rotor 110 can interact by touching or by establishing a small gap between them that is sufficiently small that an insignificant amount of the fluid to be pumped and/or compressed leaks out of the discharge space 132 b as the vane 126 rotates from the inlet port 150 toward the discharge port 160. Similarly, the outer end of the vane 126 interacts with the inner surface of the rotor housing portion 134, either by touching or by establishing a sufficiently small gap between them, so that an insignificant amount of the fluid to be pumped leaks out of the discharge space 132 b. Thus, the interaction of the valve rotor 110 with the vane rotor 120 and the interaction of the vane 126 with the rotor housing portion 134 effectively divides the pump space 132 into the inlet and discharge spaces 132 a and 132 b.
In the exemplary embodiment shown in FIGS. 1-7, the radius r₁of the valve rotor 110 is substantially twice the radius r₂of the vane rotor 120. At the same time, the timing gears 118 and 128 are designed to rotate the vane rotor 120 at twice the rotational speed of the valve rotor 110. As a consequence, in this exemplary embodiment, the surface speeds of the valve and vane rotors 110 and 120 should be substantially equal, and ideally will be equal. As a result, the surfaces of the valve and vane rotors 110 and 120, if in contact, form a substantially rolling contact or interface, rather than a substantially sliding contact or interface.
As shown in FIG. 5, the valve rotor 110 rotates counterclockwise, while the vane rotor 120 rotates clockwise. As the vane 126 rotates clockwise with the vane rotor 120, due to the effective fluid seals formed at the interaction points between the valve rotor 110 and the vane rotor 120 and between the vane 126 and the rotor housing portion 134, the gas or other fluid in the discharge space 132 b is discharged through the discharge port 160. If the fluid is compressible, it is also possible that the compressible fluid in the discharge space 132 b is also compressed.
As the vane rotor 120 rotates clockwise, the vane rotor 120 rotates from the position shown in FIG. 5 to the position shown in FIG. 6. In particular, the position shown in FIG. 6 is roughly the 180° position, where the vane 126 is at its maximum distance from the valve rotor 110. In the position shown in FIG. 6, typically, the pressure in the discharge space 132 b will now be sufficiently greater than the pressure on the downstream side of the discharge port 160 such that, if one is provided, the check valve, reed valve, or other one-way valve structure 164 will have opened to allow fluid to flow from the discharge space 132 b through the discharge port 160, past the check valve, reed valve, or other one-way valve structure 164, and into a collection structure, such as a reservoir, an accumulator, a tube, a passage, a manifold or the like.
At the same time, fluid continues to flow through the one or more inlet ports 150 from the gas/fluid supply and/or the ambient atmosphere into the inlet space 132 a. It should be appreciated that this flow of fluid from the gas/fluid supply and/or the ambient atmosphere through the inlet port 150 effectively recharges the new inlet space 132 a of the pump space 132 with a new charge of fluid to be pumped in a subsequent pump cycle. Thus, it should be appreciated that the rotary pump 100 is able to simultaneously fill the inlet space 132 a while pumping the fluid out of the discharge space 132 b through the discharge port 160. It should further be appreciated that this simultaneous filling and discharge occurs over a very large amount of rotation of the vane rotor 120. In the exemplary embodiment shown in FIGS. 1-7, this simultaneous filling and discharge occurs over about 270° or more of rotation of the vane rotor 120. In contrast, a conventional 4-vane vane pump will have no more than 90° of such rotation, and may have less if it includes more than 4 vanes.
The discharge space 132 b is created by the interaction between the valve rotor 110 and the vane rotor 120 and between the inner surface of the rotor housing portion 134 and the outer end of the vane 126. The inlet space 132 a is likewise created by the interaction point between the valve rotor 110 and the vane rotor 120 and the interface between the rotor housing portion 134 and the outer end of the vane 126. Thus, for a given pump space 132, the discharge space 132 b is generally or substantially fluidly isolated from the inlet space 132 a by the interaction points between the valve rotor 110 and the vane rotor 120 on one side and the interface between the vane 126 and the rotor housing portion 134 on the other side.
It should be appreciated that, as shown in FIG. 6, in various exemplary embodiments, the surface of the rotor body 121 of the vane rotor 120 tangently contacts the surface of the valve rotor 110. It should be appreciated that, in such exemplary embodiments, due to the relative locations of the valve rotor 110 and the rotor body 121, along with any particular surface treatment and/or material that may be provided to or on the outer surfaces of the valve rotor 110 and/or the rotor body 121 of the vane rotor 120, the valve rotor 110 and the vane rotor 120 create a rolling contact seal between them, and do not easily slide relative to one another. In various other exemplary embodiments, a non-contacting interaction between the valve rotor 110 and the vane rotor 120 nevertheless sufficiently reduces the ability of the fluid to flow from a high pressure side to a lower pressure side of the vane rotor/valve rotor interface that an effective seal is provided between the vane and valve rotors 120 and 110.
It should be appreciated that, if any additional vane rotors 120 are implemented, the pump space 132 within the vane rotor assembly 102 for that additional vane rotor 120 is isolated from the other pump spaces 132 within the other vane rotor assemblies 102 by at least the connection portions 136. This isolation can be due to the inertance and/or resistance of the small passage between the connection portions 136 and the valve rotor 110 and/or can be provided by a seal member or structure provided between the connection portion 136 and the valve rotor 110 that prevents or at least partially blocks the fluid from flowing between adjacent vane rotor assemblies 102.
It should be appreciated that, in various exemplary embodiments, the axis of rotation of the vane rotor 120 is at the center point of the generally circular pump space enclosed by the rotor housing portion 134. As a consequence, in contrast to a conventional vane pump, it is not necessary for the vanes 126 to translate or otherwise move to follow the inner surface of the rotor housing portion 134. Moreover, in contrast to a conventional vane pump, the shape of the pump space does not need to change as a function of the rotation position of the vane 126, and the distance between the surface of the vane rotor 120 and the inner surface of the rotor housing portion 134 is generally constant.
As the vane rotor 120 rotates, the volume of the discharge space 132 b decreases, while the volume of the inlet space 132 a increases. Because the amount of fluid present in the pump space 132 when the leading edge of the vane 126 completely passes by the inlet port 150 is effectively constant and experiences an ever-decreasing volume as the vane rotor 120 rotates, the fluid in the discharge space 132 b must either be discharged through the discharge port 160 and/or the fluid in the discharge space 132 b must be compressed. If the fluid is compressed, or if the flow through the discharge port 160 is restricted such that the flow rate through the discharge port 160 at the instantaneous pressure within the discharge space 132 b is less than the volume decrease rate of the discharge space 132 b, the pressure on the fluid in the discharge space 132 b increases.
At the same time, once the trailing edge of the vane 126 passes by the front edge of the inlet port 150, fluid can begin flowing through the inlet port 150 into the inlet space 132 a. Because the inlet space 132 a initially starts at a volume of effectively about zero and continually increases, the inlet space 132 a tends to be below the pressure of the fluid on the other side of the inlet port 150 as the vane rotor 120 rotates. Accordingly, due to this pressure differential, fluid tends to flow through the inlet port 150 from the connected fluid supply and/or the ambient atmosphere into the inlet space 132 a of the pump space 132.
As the vane rotor 120 continues to rotate clockwise, the vane rotor 120 rotates clockwise from the position shown in FIG. 6 to the position shown in FIG. 7. As shown in FIG. 7, the vane rotor 120 has rotated approximately 330° from the zero degree position, while the valve rotor has rotated approximately 165° from the zero degree position. Significantly, as shown in FIG. 7, the vane 126 has entered a second slot or channel 116 and closely approaches, if not contacts, the surface of the valve rotor 110 in the slot or channel 116.
At the same time, the outer surface of the vane rotor 120 no longer contacts the outer surface of the valve rotor 110, as the leading edge of the slot or channel 116 has moved past the 0° point, i.e., the tangent point or line connecting the axis of the valve rotor 110 with the axis of the vane rotor 120. As a result, the inlet space 132 a and the discharge space 132 b of the pump space 132 need no longer be isolated from each other. Thus, only the undivided pump space 132 effectively exists. Nonetheless, a volume of the pump space 132 is larger than the volume of inlet space 132 a, such that fluid from the gas/fluid supply and/or the ambient atmosphere continues to flow through the inlet port(s) 150 into the pump space 132 to continue to recharge the pump space 132 with fluid to be pumped.
As previously indicated, the pressure in the pump space 132 is at most equal to the pressure in the gas/fluid supply and/or the ambient atmosphere. Accordingly, if one has been provided, the check valve, reed valve, or other one-way valve structure 164 is now completely closed, as the pressure on the downstream side of the discharge port 160 will be at least equal to the pressure in the pump space 132. The vane rotor 120 continues to rotate clockwise, returning to the zero degree (0°) position shown in FIG. 5, such that the vane rotor 120 is again ready to pump a charge of fluid in the pump space 132, discharging it through the discharge port 160 and, if one has been provided, past the check valve, reed valve, or other one-way valve structure 164.
Accordingly, it should be appreciated that, in various rotary pumps according to this invention, the vane rotor 120, as it rotates within the corresponding rotor housing portion 134, simultaneously discharges fluid through the one or more discharge ports 160 as it draws in the next or later charge of fluid to be pumped through the one or more inlet ports 150. However, in contrast to conventional rotary gear pumps or the like, the vane rotor 120 does not interact with another vane rotor 120, but interacts only with the valve rotor 110.
The preceding detailed description of the exemplary embodiment shown in FIGS. 5-7 assumes that the inlet ports 150 and/or the discharge ports 160 are located in the rotor housing portions 134. However, it should be appreciated that either, or both, of the inlet ports 150 and/or the discharge ports 160 could be located in the connecting portions 136. In this case, the gas and/or fluid drawn into the inlet space 132 a through such an inlet port 150 will flow between one connecting portion 136 and the outer surface of the valve rotor 110. Accordingly, the vane rotor 120 will isolate a portion of the pump space 132 from the inlet port 150 to create the discharge space 132 b and the inlet space 132 a as soon as the leading edge of the vane 126 contacts the inner surface of the rotor housing portion 134. Consequently, the initial volume of the discharge space 132 b will be larger, while the initial volume of the inlet space 132 a will be smaller.
Likewise, the fluid to be discharged from the discharge space 132 b through the discharge port 160 will flow between another connecting portion 136 and the outer surface of the valve rotor 110 to reach the discharge port 160 from the discharge space 132 b. Accordingly, the pumped fluid will continue to flow to such a discharge port 160 until the leading edge of the slot or channel 116 has almost returned to, or even passes by, the zero degree (0°) position between the valve rotor 110 and the vane rotor 120. Consequently, the final volume of the discharge space 132 b will tend to be smaller, while the pumped volume, and possibly the maximum compression pressure and compression ratio of the vane rotor 120 will tend to be higher. In other words, the displacement area and corresponding amount of rotation of the vane rotor 120 over which filling and discharge occurs is increased. Thus, this alternative design can be more efficient.
In various other exemplary embodiments, a driving contact can be formed between the outer surface of the valve rotor 110 and the outer surface of the vane rotor 120, in place or in addition to the timing/drive gears of appropriate sizes that are typically associated with the valve rotor 110 and the vane rotor 120. As outlined above, timing/drive gears of appropriate sizes are typically placed around, and attached or otherwise fixed to, either or both of the first and second support shafts 112 and 114 of the valve rotor 110 and either or both of the first and second support shafts 122 and 124 of the vane rotor 120. Alternatively, as discussed above, each of the valve rotor 110 and the vane rotor 120 can be provided with increased radii portions in which gear teeth can be formed. These increased radii portions can then be assembled to allow the gear teeth formed in the valve rotor 110 and in the vane rotor 120 to intermesh to provide the timing/drive gear structure between the valve rotor 110 and the vane rotor 120.
The foregoing description of FIGS. 5-7 describes the operation of the rotary pump 100 when used to pump a fluid based on a rotational drive force transmitted to the rotary pump 100 via the first and/or second support shafts 122 and/or 124 of the vane rotor 120. However, if the inlet ports 150 are attached to a relatively higher-pressure fluid source and the discharge ports 160 are attached to a relatively lower pressure discharge reservoir, and the rotary pump 100 is provided with an auxiliary starter motor (similarly to that provided to an internal combustion motor) or by using the timing gears as a second air motor, the rotary pump 100 can instead be operated as an air or fluid motor.
That is, when relatively higher-pressure fluid enters the inlet spaces 132 a from the inlet ports 150, that fluid can be used to provide the drive energy necessary to push against the vane 126 to rotate the vane rotor 120 through the cycle of positions shown in FIGS. 5-7 (not in that order). This driven rotation of a vane rotor 120 can be used as a source of rotational power/energy output from the rotary pump (now motor) 100. When coupled with similar driven rotations of one or more additional vane rotors 120 that can be provided around the circumference of the valve rotor 110, this driven rotation of the vane rotors 120 can be transmitted by the timing/drive gear train to rotate the valve rotor 110. This driven rotation of the valve rotor 110 can be used as a source of rotational power/energy output from the rotary pump (motor) 100.
As indicated above, it should be appreciated that, in place of a separate auxiliary starter motor, the timing gears 118 and/or 128 can be used as an air starter motor for the single-vane embodiment of the rotary pump 100 shown in FIGS. 1-7 when it is used as an air or fluid motor. In this exemplary embodiment, the timing gears 118 and 128 also act as the gears of a gear pump or motor, such that, when a high-pressure fluid is directed against the timing gears 118 and/or 128, the timing gears 118 and 128 rotate in response, thus causing the valve and vane rotors 110 and 120 to rotate as well.
Additionally, if one or more of the additional vane rotors 120 are connected to a separate fluid source, such as the ambient atmosphere, the rotary pump 100 can use the energy from the higher-pressure fluid source to pump fluid from the other, separate fluid source into a structure that is downstream of the discharge ports 160 of those additional vane rotors 120. That is, the rotary pump can be used as a supercharger or in a manner similar to a turbocharger. However, in this case, the rotary pump (or motor) 100 is not necessarily being driven by an exhaust gas stream.
FIG. 8 shows in greater detail a second exemplary embodiment of a rotary pump 200 according to this invention, including a second exemplary embodiment of a vane rotor 220, an associated surrounding rotor housing portion 234 and adjacent connecting portions 236 of the rotor housing 230 and an adjacent portion of a valve rotor 210. The vane rotor 220 and the associated portions of the rotor housing 230 form a vane rotor assembly 202 of the rotary pump 200. In particular, in FIG. 8, the rotor body 221 of the vane rotor 220 is positioned relative to the valve rotor 210 at a zero degree (0°) position of a first vane 226, while a second vane 226 is located at its 180° position. In this zero degree (0°) position of the first vane 226, the first vane 226 faces the valve rotor 210 and is positioned within a central portion of the slot or channel 216. At the same time, the outer surface of the second vane 226 is adjacent to, and forms an interface with, the inner surface of the rotor housing portion 234.
As in the first exemplary embodiment shown in FIGS. 1-7, fluid enters a pump space 232 through one or more inlet ports 250, while fluid exits the pump space 232 through one or more discharge ports 260. It should be appreciated that, in this exemplary embodiment, because there are more a plurality of vanes 226, it is not necessary to provide a check valve in the discharge port 260. It should also be appreciated that each vane 226 generally should form an effective seal with the slot or channel 216. A seal is generally desirable in this exemplary embodiment, as there is generally a pressure difference between the upstream and downstream sided of the vane 226 when it is in the slot or channel 216.
Thus, in this position, the first and second vanes 226 divide the pump space or volume 232 into an inlet space 232 a and a discharge space 232 b, even when the first or second vane 226 is in, entering or leaving one of the slots or channels 216. It should be understood that the interface between a vane 226 and a slot or channel 216 can be contact between these elements, a close approach between these elements, such that a small gap is established between these elements, or any other desired and appropriate relationship. If a gap is established, in various exemplary embodiments, the gap is on the order of about 0.005 inch. A gap of this size may be appropriate for a cold rotary pump 200 when used in a low duty cycle, low speed, and/or low pressure regime. A gap of this size may be appropriate for a hot rotary pump 200 when used for extended periods, and/or in a high speed and/or high pressure regime. Of course, other size gaps may be appropriate for a particular use and for particular materials.
Thus, it should be appreciated that it may be possible, or even probable, for the fluid within the discharge space 232 b to leak from the discharge space 232 b to the inlet space 232 a as one of the vanes 226 passes from the downstream end of the pump space 232 to the upstream end of the pump space 232. However, it should be understood that any such leakage will not significantly affect the operation of the rotary pump 200.
In FIG. 9, the trailing edge of the first vane 226 has completely passed by the leading edge of the inlet port 250. Accordingly, a new inlet space 232 a is established behind the first vane 226, while the previous inlet space 232 a in front of this first vane 226 becomes a displacement or transport space 232 c. Because the discharge space 232 b experiences an ever-decreasing volume as the vane rotor 220 rotates, the fluid in the discharge space 232 b must either be discharged through the discharge port 260 and/or the fluid in the discharge space 232 b must be compressed. If the fluid is compressed, or if the flow through the discharge port 260 is restricted such that the flow rate through the discharge port 260 at the instantaneous pressure within the discharge space 232 b is less than the volume decrease rate of the discharge space 232 b, the pressure on the fluid in the discharge space 232 b increases.
At the same time, because the slot or channel 216 in the valve rotor 210 has also moved completely passed the zero degree (0°) position, the outer surface of the valve rotor 210, having the radius r₁, sealingly interacts with the outer surface of the vane rotor 220, having the radius r₂. In this exemplary embodiment, as in the first exemplary embodiment shown in FIGS. 1-7, the ratio of the radii r₂/r₁is generally equal to the ratio of the rotational speed of the vane rotor 220 over the rotational speed of the valve rotor 210. As a consequence, the translational speeds of the surfaces of the valve and vane rotors 210 and 220 are generally equivalent, so that a generally rolling contact or interaction is established between the valve and vane rotors 210 and 220. Accordingly, an effective seal is created both at the interaction point between the vane rotor 220 and the valve rotor 210 and at the interface region between the outer surface of the first vane 226 and the inner surface of the rotor housing portion 234, establishing the new inlet space 232 a and fluidly isolating it from the transport space 232 c and the discharge space 232 b.
Once the trailing edge of the first vane 226 passes by the front edge of the inlet port 250, fluid can begin flowing through the inlet port 250 into the new inlet space 232 a. Because the new inlet space 232 a initially starts at a volume of about zero and continually increases, the inlet space 232 a tends to be below the pressure of the fluid on the other side of the inlet port 250 as the vane rotor 220 rotates. Accordingly, due to this pressure differential, fluid tends to flow through the inlet port 250 from the connected fluid supply and/or the ambient atmosphere into the inlet space 232 a of the pump space 232. At the same time, the fluid in the transport space 232 c defined between the first and second vanes 226 continues to be transported toward the discharge port 260. Similarly, the fluid in the discharge space 232 b continues to be pumped out through the discharge port 260 and/or compressed.
Thus, it should be appreciated that the rotary pump 200 is able to simultaneously fill the inlet space 232 a while pumping the fluid out of the discharge space 232 b through the discharge port 260. It should further be appreciated that this simultaneous filling and discharge occurs over a very large amount of rotation of the vane rotor 220. In the exemplary embodiment shown in FIGS. 8 and 9, this simultaneous filling and discharge occurs over about 180° of rotation of the vane rotor 220. In contrast, a conventional 4-vane vane pump will have no more than 90° of such rotation, and may have less if it includes more than 4 vanes.
Likewise, it is not necessary to form a fluid-tight seal between the vanes 226 and the rotor housing portion 234. Like the interaction between the vane 226 and the slot or channel 216, the interaction between the vane 226 and the inner surface of the rotor housing portion 234 effectively prevents much, if any, fluid from passing from the discharge space 232 b of the pump space 232 to the inlet space 232 a or the transport space 232 c of the pump space 232. Thus, the interaction of the valve rotor 210 with the vane rotor 220 and the interaction of the first and second vanes 226 with both the vane rotor 220 and the rotor housing portion 234 effectively fluidly divides the pump space 232 into the three spaces 232 a, 232 b and 232 c.
As in the exemplary embodiment shown in FIGS. 5-7, in FIGS. 8 and 9, the valve rotor 210 rotates counterclockwise as the vane rotor 220 rotates clockwise. As the first and second vanes 226 rotate clockwise with the vane rotor 220, due to the effective seals formed at the interaction points between the valve rotor 210 and the vane rotor 220 and the interfaces between the first and second vanes 226 and the rotor housing portion 234, the gas or other fluid in the discharge space 232 b is discharged through the discharge port 260. If the fluid is compressible, it is also possible that the compressible fluid in the discharge space 232 b is also compressed.
As the vane rotor 220 rotates clockwise, the timing/drive gears cause the valve rotor 210 to rotate counterclockwise (or vice versa) from the position shown in FIG. 8 to the position shown in FIG. 9. Due to this rotation, the first vane 226 rotates toward and then past the inlet port 250. At the same time, the second vane 226 rotates toward the discharge port 260. In FIG. 9, both the slot or channel 216 and the first vane 226 have moved away from the zero degree (0°) position of the vane rotor 220 shown in FIG. 8, such that the outer surfaces of the vane rotor 220 and the valve rotor 210 establish an interaction region between them.
As the valve rotor 210 continues to rotate counterclockwise, and the vane rotor 220 continues to rotate clockwise, the volume of the original discharge space 232 b decreases to zero, until the second vane 226 passes by the discharge port 260. At that time, the previous transport space 232 c becomes a new discharge space 232 b. That is, when the trailing edge of the second vane 226 completely passes by the leading edge of the discharge port(s) 260, the transport space 232 c is fluidly connected to the discharge port(s) 260, becoming the next current discharge space 232 b. From that point, the volume of the current discharge space 232 b begins to decrease relative to the volume of the transport space 232 c shown in FIG. 9. Meanwhile, the volume of the inlet space 232 a continues to increase.
Accordingly, it should be appreciated that, in the second exemplary embodiment of the rotary pump 200 according to this invention, the vane rotor 220, as it rotates within the corresponding rotor housing portion 234, simultaneously discharges fluid from the discharge space 232 b through the one or more discharge ports 260, while it simultaneously transports fluid in the transport space 232 c from the inlet port(s) 250 to the discharge port(s) 260 and draws in the next charge of fluid to be pumped into the inlet space 232 a through the one or more inlet ports 250.
The foregoing description of FIGS. 8 and 9 describes the operation of the rotary pump 200 when used to pump a fluid based on a rotational drive force transmitted to the rotary pump 200 via the support shaft 222 of the vane rotor 220. However, if the inlet ports 250 are attached to a relatively higher-pressure fluid source and the discharge ports 260 are attached to a relatively lower pressure discharge reservoir, the rotary pump 200 can instead be operated as a motor as outlined above with the first exemplary embodiment shown in FIGS. 1-7. However, in this exemplary embodiment, because there are a plurality of vanes, it is not necessary to provide the rotary pump (motor) 200 with an auxiliary starter motor.
FIGS. 10 and 11 show in greater detail a third exemplary embodiment of a rotary pump 300 according to this invention, including a third exemplary embodiment of a vane rotor 320, an associated surrounding rotor housing portion 334 and adjacent connecting portions 336 of the housing 330 and an adjacent portion of a valve rotor 310. The vane rotor 320 and the associated portions of the housing 330 form a vane rotor assembly 302 of the rotary pump 300. In particular, in FIG. 10, the rotor body 321 of the vane rotor 320 is positioned relative to the valve rotor 310 at a zero degree (0°) position of a first vane 326, while a second vane 326 is located at its 120° position and a third vane 326 is located at its 240° position.
As in the first and second exemplary embodiments shown in FIGS. 1-9, fluid enters a pump space 332 through one or more inlet ports 350, while fluid exits the pump space 332 through one or more discharge ports 360. It should be appreciated that, in this exemplary embodiment, because there are more a plurality of vanes 326, it is not necessary to provide a check valve in the discharge port 360. It should also be appreciated that each vane 326 generally should form an effective seal with the slot or channel 316. A seal is generally desirable in this exemplary embodiment, as there is generally a pressure difference between the upstream and downstream sided of the vane 326 when it is in the slot or channel 316.
In the zero degree (0°) position of the first vane 326 shown in FIG. 10, the first vane 326 faces the valve rotor 310 and is located within a central portion of a slot or channel 316. At the same time, the outer surfaces of the second and third vanes 326 face the inner surface of the rotor housing portion 334. Thus, in this position, the first, second and third vanes 326 effectively fluidly divide the pump space or volume 332 into an inlet space 332 a, a discharge space 332 b, and a first transport space 332 c, even when one of the first, second or third vane 326 is in, entering or leaving one of the slots or channels 316.
It should be understood that the interface between a vane 326 and a slot or channel 316 can be contact between these elements, a close approach between these elements, such that a small gap is established between these elements, or any other desired and appropriate relationship. If a gap is established, in various exemplary embodiments, the gap is on the order of about 0.005 inch. A gap of this size may be appropriate for a cold rotary pump 300 when used in a low duty cycle, low speed, and/or low pressure regime. A gap of this size may be appropriate for a hot rotary pump 300 when used for extended periods, and/or in a high speed and/or high pressure regime. Of course, other size gaps may be appropriate for a particular use and for particular materials.
Thus, it should be appreciated that it may be possible, or even probable, for the fluid within the discharge space 332 b to leak from the discharge space 332 b to the inlet space 332 a as one of the vanes 326 passes from the downstream end of the pump space 332 to the upstream end of the pump space 332. However, it should be understood that any such leakage will not significantly affect the operation of the rotary pump 300.
In the third exemplary embodiment shown in FIG. 10, the relative positions of the first, second and third vanes 326 and the slots or channels 316 are illustrated. The discharge space 332 b is created by the interfaces between the valve rotor 310 and first vane 326 and between the inner surface of the rotor housing portion 334 and the outer surface of the third vane 326. The first transport space 332 c is created by the interface between the rotor housing portion 334 and the outer surfaces of the second and third vanes 326. At the same time, the inlet space 332 a is formed by the interface between the inner surface of the rotor housing portion 334 and the outer surface of the second vane 326 at one end and the interface between the valve rotor 310 and the first vane 326.
In the position of the vane rotor 320 shown in FIG. 10, as the vane rotor 320 rotates clockwise, the volume of the discharge space 332 b decreases until the third vane 326 completely covers the discharge port(s) 360. In contrast, the volume of the inlet space 332 a increases until the first vane 326 completely covers the inlet port(s) 350. Because the discharge space 332 b experiences an ever-decreasing volume as the vane rotor 320 rotates clockwise, the fluid in the discharge space 332 b must either be discharged through the discharge port(s) 360 and/or the fluid in the discharge space 332 b must be compressed. If the fluid is compressed, or if the flow through the discharge port(s) 360 is restricted such that the flow rate through the discharge port 360(s) at the instantaneous pressure within the discharge space 332 b is less than the volume decrease rate of the discharge space 332 b, the pressure on the fluid in the discharge space 332 b increases.
In FIG. 10, the vane rotor 320 pumps, and possibly compresses, the fluid present in the discharge space 332 b. Because the leading edge of the first vane 326 has not yet reached the trailing edge of the inlet port(s) 350, the volume of the inlet space 332 a continues to increase, such that fluid continues to enter the inlet space 332 a. As the vane rotor 320 rotates clockwise, the timing/drive gears cause the valve rotor 310 to rotate counterclockwise from the position shown in FIG. 10, while the first vane 326 is rotated toward and then past the inlet port 350, to the position shown in FIG. 11. At the same time, the second and third vanes 326 rotate toward the discharge port 360. In FIG. 11, both the slot or channel 316 and the first vane 326 have moved away from the zero degree (0°) position of the vane rotor 320 shown in FIG. 10, while the second and third vanes 326 have moved toward the discharge port(s) 360.
In particular, FIG. 11 shows that, in this position, the first vane 326 faces the inner surface of the rotor housing portion 334. As shown in FIG. 11, the leading edges of the first vane 326 has passed the inlet port(s) 350. At this point, the amount of fluid present in the inlet space 332 a when the leading edge of the first vane 326 completely passed by the inlet port 350 is effectively constant and thus the inlet space 332 a becomes a second transport space 332 d. At the same time, a new inlet space 232 a is established behind the first vane 326.
Because the slot or channel 316 in the valve rotor 310 has also moved completely past the zero degree (0°) position, the outer surface of the valve rotor 310, having the radius r₁, sealingly interacts with the outer surface of the vane rotor 320, having the radius r₂. Accordingly, an effective seal is created both at the interaction point between the vane rotor 320 and the valve rotor 310 and at the interface between the outer surface of the first vane 326 and the inner surface of the rotor housing portion 334, establishing the new inlet space 332 a and fluidly isolating it from the new second transport space 332 d and the discharge space 332 b.
Thus, it should be appreciated that the rotary pump 300 is able to simultaneously fill the inlet space 332 a while pumping the fluid out of the discharge space 332 b through the discharge port 360. It should further be appreciated that this simultaneous filling and discharge occurs over a very large amount of rotation of the vane rotor 320. In the exemplary embodiment shown in FIGS. 10 and 11, this simultaneous filling and discharge occurs over about 120° of rotation of the vane rotor 320. In contrast, a conventional 4-vane vane pump will have no more than 90° of such rotation, and may have less if it includes more than 4 vanes.
Likewise, it is not necessary to form a fluid-tight seal between the vanes 326. Like the interaction between the vane 326 and the slot or channel 316, the interaction between the vane 326 and the inner surface of the rotor housing portion 334 effectively prevents much, if any, fluid from passing from the discharge space 332 b of the pump space 332 to the inlet space 332 a or the first transport space 332 c of the pump space 332. Thus, the interaction of the valve rotor 310 with the vane rotor 320 and the interaction of the first and second vanes 326 with both the vane rotor 320 and the rotor housing portion 334 effectively fluidly divides the pump space 332 into the three spaces 332 a, 332 b and 332 c.
In the exemplary embodiments described above, the valve rotor 310 continues to rotate counterclockwise as the vane rotor 320 continues to rotate clockwise. In particular, once the trailing edge of the first vane 326 passes by the front edge of the inlet port(s) 350, fluid can begin flowing through the inlet port 350 into the new inlet space 332 a. Because the new inlet space 332 a initially starts at a volume of about zero and continually increases, the inlet space 332 a tends to be below the pressure of the fluid on the other side of the inlet port(s) 350 as the vane rotor 320 rotates. Accordingly, due to this pressure differential, fluid tends to flow through the inlet port 350 from the connected fluid supply and/or the ambient atmosphere into the inlet space 332 a of the pump space 332. At the same time, the fluid charges in the first and second transport spaces 332 c and 332 d defined between the second and third vanes 326, and between the first and second vanes 326, respectively, continue to be transported toward the discharge port(s) 360.
As the first and second vanes 326 rotate clockwise with the vane rotor 320, due to the effective seals formed at the interaction points between the valve rotor 310 and the vane rotor 320 and the interfaces between the first, second and third vanes 326 and the rotor housing portion 334, the gas or other fluid in the discharge space 332 b is discharged through the discharge port 360. If the fluid is compressible, it is also possible that the compressible fluid in the discharge space 332 b is also compressed.
Accordingly, it should be appreciated that, in the third exemplary embodiment of the rotary pump 300 according to this invention, the vane rotor 320, as it rotates within the corresponding rotor housing portion 334, simultaneously discharges fluid from the discharge space 332 b through the one or more discharge ports 360, while it transports fluid in the first and second transport spaces 332 c and 332 d from the inlet port(s) 350 to the discharge port(s) 360 and draws in the next charge of fluid to be pumped into the inlet space 332 a through the one or more inlet ports 350.
The foregoing description of FIGS. 10 and 11 describes the operation of the rotary pump 300 when used to pump a fluid based on a rotational drive force transmitted to the rotary pump 300 via the support shaft 322 of the vane rotor 320. However, if the inlet ports 350 are attached to a relatively higher-pressure fluid source and the discharge ports 360 are attached to a relatively lower pressure discharge reservoir, the rotary pump 300 can instead be operated as a motor. In this exemplary embodiment, because there are a plurality of vanes, it is not necessary to provide the rotary pump 300 with an auxiliary starter motor.
FIGS. 12-14 illustrate a second exemplary shape for the vane 126 and consequently for the slot or channel 116 of the vane rotor 120 and the corresponding valve rotor 110 shown in FIGS. 1-7. FIGS. 12-14 illustrate that the vane 126-326 and associated slots or channels 116-316 need not be limited to the shape shown in FIGS. 1-11. Of course the vanes 226 and/or 326 and the associated slots or channels 216 and/or 316, respectively, can also use this shape. It should be appreciated that the vanes 126-326 can have any desired and/or appropriate shape, so long as the vane(s) are able to effectively isolate the various sections of the pump space 132-332 from each other. It should further be appreciated that the shape of this second exemplary embodiment of the slot or channel 116 can be developed or not, as desired.
It should further be appreciated that the vanes 126-326 can be formed integrally with the respective vane rotors 120-130, as shown in FIGS. 1-14. Alternatively, the vanes 126-326 can be separate members that are physically connected to the respective vane rotors 120-320 or that are shaped such that they are held generally stationary relative to the respective vane rotors 120-320. In still other alternative exemplary embodiments, the vanes 126-326 can “float” within slots formed in the respective vane rotors 120-320. In such exemplary embodiments, even though the vanes 126-326 float relative to the vane rotors 120-320, the positions of the vanes 126-326 within the slots are generally unchanging. Typically, the vanes 126-326 would move within the slots only to compensate for small changes in the radius of the inner surfaces of the rotor housing portions 134-334 and/or the surfaces of the slots or channels 116-316 due to manufacturing tolerances and/or wear.
While this invention has been described in conjunction with the exemplary embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the exemplary embodiments of the invention, as set forth above, are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit or scope of the invention. Therefore, the invention is intended to embrace all known or earlier developed alternatives, modifications, variations, improvements and/or substantial equivalents.

Claims

1. A rotary pump, comprising:

a valve rotor having an outer surface;

at least one vane rotor arranged around the periphery of the valve rotor; and

a housing around the at least one vane rotor and the valve rotor, the housing having an inner surface and forming a pump space around each vane rotor; wherein each vane rotor comprises:

a rotor body having an outer surface, and

at least one vane, each at least one vane rotating with the rotor body and movable within the pump space provided around that vane rotor;

wherein, for each vane rotor:

the valve rotor and that vane rotor rotate in a coordinated manner, and

at various rotational positions of that vane rotor relative to the valve rotor, the outer surface of the rotor body sealingly interacts with the outer surface of the valve rotor and each vane sealingly interacts with the inner surface of the housing to divide the pump space around that vane rotor into at least two portions that are substantially fluidly isolated from each other.

2. The rotary pump of claim 1, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor sealingly interacts with the outer surface of the valve rotor by contacting the outer surface of the valve rotor at a corresponding contact point.

3. The rotary pump of claim 2, wherein a rotation of the valve rotor in a first direction matched by a corresponding rotation of that rotor body in a second direction opposite the first direction, such that a generally rolling contact is provide between the valve rotor and that vane rotor.

4. The rotary pump of claim 3, wherein the outer surface of the rotor body of that vane rotor sealingly contacts the outer surface of the valve rotor at the corresponding contact point.

5. The rotary pump of claim 2, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor sealingly interacts with the outer surface of the valve rotor at an interaction point by establishing a sufficiently small gap between them at the interaction point, such that, for an amount of a desired fluid to be pumped in the pump space, only an insubstantial portion of the amount of the fluid in the pump space is able to pass through the gap.

6. The rotary pump of claim 1, wherein:

the valve rotor has at least one channel formed in its outer surface; and

each of the at least one vane is able to extend into each channel formed in the outer surface of the valve rotor.

7. The rotary pump of claim 6, wherein:

each channel has an interior surface; and

for each vane, an outer surface of the vane sealingly interacts with the interior surface of that channel as the vane passes from a discharge end to an inlet end of the pump space.

8. The rotary pump of claim 7, wherein, for each vane, the outer surface of that vane sealingly interacts with the interior surface of that channel by contacting the interior surface of that channel as the vane passes from the discharge end to the inlet end of the pump space.

9. The rotary pump of claim 7, wherein, for each vane, the outer surface of that vane rotor sealingly interacts with the interior surface of that by establishing a sufficiently small gap between them as the vane passes from the discharge end to the inlet end of the pump space, such that, for an amount of a desired fluid to be pumped in the pump space, only an insubstantial portion of the amount of the fluid in the pump space is able to pass through the gap.

10. The rotary pump of claim 6, wherein:

as the valve rotor and a vane rotor rotates, a vane of that vane rotor approaches a corresponding interaction point between the rotor body of that vane rotor and the valve rotor, one of the at least one channel formed in the outer surface of the valve rotor approaches the interaction point between the rotor body of that vane rotor and the valve rotor such that the vane extends into that channel to allow that vane to move from a discharge end of the pump space for that vane rotor to an inlet end of the space for that vane rotor.

11. The rotary pump of claim 1, wherein, for at least one vane rotor:

that vane rotor is located within a corresponding rotor housing portion of the housing, that rotor housing portion having an inlet end and an discharge end; and

a distance from the outer surface of rotor body of that vane rotor to the inner surface of the rotor housing portion is generally constant.

12. The rotary pump of claim 11, wherein:

as that vane rotor rotates within the corresponding rotor housing portion such that, as each vane rotates from the inlet end to the discharge end, that vane interacts with the inner surface of the corresponding rotor housing portion to create an effective fluid seal.

13. The rotary pump of claim 1, wherein, for at least one vane rotor:

that vane rotor is located within a corresponding rotor housing portion of the housing, each rotor housing portion having an inlet end and an discharge end; and

a radial extent of the pump space around that vane rotor from the inlet end to the discharge end is generally constant.

14. The rotary pump of claim 13, wherein:

15. The rotary pump of claim 1, wherein, for at least one vane rotor, each vane of that vane rotor is integrally formed with that vane rotor.

16. The rotary pump of claim 1, wherein, for at least one vane rotor, each vane of that vane rotor is connected to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

17. The rotary pump of claim 1, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

18. The rotary pump of claim 1, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

19. The rotary pump of claim 1, further comprising:

a first gear associated with and rotationally fixed to the valve rotor; and

for each of the at least one vane rotor, a second gear associated with and rotationally fixed to that vane rotor;

wherein each second gear is engaged with the first gear, such that the valve rotor and the at least one vane rotor are rotationally coordinated by the first gear and at least one second gear.

20. A rotary pump, comprising:

a valve rotor having an outer surface;

at least one vane rotor having an outer surface, wherein each vane rotor is positioned relative to the circumference of the valve rotor such that at least one point around the outer surface of each vane rotor is at substantially a same radial position from a center point of the valve rotor as at least one point of the outer surface of the valve rotor;

a housing around the at least one vane rotor and the valve rotor, at least one of the valve rotor and the housing forming a pump space around each vane rotor; and

at least one vane provided on each vane rotor, each such vane extending radially away from the outer surface of that vane rotor, each such vane rotating with that vane rotor and movable within the pump space provided around that vane rotor;

wherein, for each vane rotor:

the valve rotor and that vane rotor rotate in a coordinated manner, and at various rotational positions of that vane rotor relative to the valve rotor, the outer surface of the rotor body sealingly interacts with the outer surface of the valve rotor and each vane sealingly interacts with the inner surface of the housing to divide the pump space around that vane rotor into at least two portions that are substantially fluidly isolated from each other.

21. The rotary pump of claim 20, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor contacts the outer surface of the valve rotor at a corresponding contact point.

22. The rotary pump of claim 21, wherein a rotation of the valve rotor in a first direction matched by a corresponding rotation of that rotor body in a second direction opposite the first direction, such that a generally rolling contact is provide between the valve rotor and that vane rotor.

23. The rotary pump of claim 22, wherein the outer surface of the rotor body of that vane rotor sealingly contacts the outer surface of the valve rotor at the corresponding contact point.

24. The rotary pump of claim 21, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor sealingly interacts with the outer surface of the valve rotor at an interaction point by establishing a sufficiently small gap between them at the interaction point, such that, for an amount of a desired fluid to be pumped in the pump space, only an insubstantial portion of the amount of the fluid in the pump space is able to pass through the gap.

25. The rotary pump of claim 20, wherein:

the valve rotor has at least one channel formed in its outer surface; and

26. The rotary pump of claim 25, wherein:

each channel has an interior surface; and

27. The rotary pump of claim 26, wherein, for each vane, the outer surface of that vane sealingly interacts with the interior surface of that channel by contacting the interior surface of that channel as the vane passes from the discharge end to the inlet end of the pump space.

28. The rotary pump of claim 26, wherein, for each vane, the outer surface of that vane rotor sealingly interacts with the interior surface of that by establishing a sufficiently small gap between them as the vane passes from the discharge end to the inlet end of the pump space, such that, for an amount of a desired fluid to be pumped in the pump space, only an insubstantial portion of the amount of the fluid in the pump space is able to pass through the gap.

29. The rotary pump of claim 25, wherein:

30. The rotary pump of claim 20, wherein, for at least one vane rotor:

31. The rotary pump of claim 30, wherein:

32. The rotary pump of claim 20, wherein, for at least one vane rotor:

33. The rotary pump of claim 32, wherein:

34. The rotary pump of claim 20, wherein, for at least one vane rotor, each vane of that vane rotor is integrally formed with that vane rotor.

35. The rotary pump of claim 20, wherein, for at least one vane rotor, each vane of that vane rotor is connected to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

36. The rotary pump of claim 20, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

37. The rotary pump of claim 20, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

38. The rotary pump of claim 20, further comprising:

a first gear associated with and rotationally fixed to the valve rotor; and

39. A rotary motor, comprising:

a valve rotor having an outer surface;

at least one vane rotor arranged around the periphery of the valve rotor; and

a housing around the at least one vane rotor and the valve rotor, the housing having an inner surface and forming a motor space around each vane rotor; wherein each vane rotor comprises:

a rotor body having an outer surface, and

at least one vane, each at least one vane rotating with the rotor body and movable within the motor space provided around that vane rotor;

wherein, for each vane rotor:

the valve rotor and that vane rotor rotate in a coordinated manner, and

at various rotational positions of that vane rotor relative to the valve rotor, the outer surface of the rotor body sealingly interacts with the outer surface of the valve rotor and each vane sealingly interacts with the inner surface of the housing to divide the motor space around that vane rotor into at least two portions that are substantially fluidly isolated from each other.

40. The rotary motor of claim 39, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor sealingly interacts with the outer surface of the valve rotor by contacting the outer surface of the valve rotor at a corresponding contact point.

41. The rotary motor of claim 40, wherein a rotation of the valve rotor in a first direction matched by a corresponding rotation of that rotor body in a second direction opposite the first direction, such that a generally rolling contact is provide between the valve rotor and that vane rotor.

42. The rotary motor of claim 41, wherein the outer surface of the rotor body of that vane rotor sealingly contacts the outer surface of the valve rotor at the corresponding contact point.

43. The rotary motor of claim 40, wherein, for each vane rotor, the outer surface of the rotor body of that vane rotor sealingly interacts with the outer surface of the valve rotor at an interaction point by establishing a sufficiently small gap between them at the interaction point, such that, for an amount of a desired fluid to be introduced into the motor space, only an insubstantial portion of the amount of the fluid in the motor space is able to pass through the gap.

44. The rotary motor of claim 39, wherein:

the valve rotor has at least one channel formed in its outer surface; and

45. The rotary motor of claim 44, wherein:

each channel has an interior surface; and

for each vane, an outer surface of the vane sealingly interacts with the interior surface of that channel as the vane passes from a discharge end to an inlet end of the motor space.

46. The rotary motor of claim 45, wherein, for each vane, the outer surface of that vane sealingly interacts with the interior surface of that channel by contacting the interior surface of that channel as the vane passes from the discharge end to the inlet end of the motor space.

47. The rotary motor of claim 45, wherein, for each vane, the outer surface of that vane rotor sealingly interacts with the interior surface of that by establishing a sufficiently small gap between them as the vane passes from the discharge end to the inlet end of the motor space, such that, for an amount of a desired fluid to introduced into the motor space, only an insubstantial portion of the amount of the fluid in the motor space is able to pass through the gap.

48. The rotary motor of claim 44, wherein:

as the valve rotor and a vane rotor rotates, a vane of that vane rotor approaches a corresponding interaction point between the rotor body of that vane rotor and the valve rotor, one of the at least one channel formed in the outer surface of the valve rotor approaches the interaction point between the rotor body of that vane rotor and the valve rotor such that the vane extends into that channel to allow that vane to move from a discharge end of the motor space for that vane rotor to an inlet end of the space for that vane rotor.

49. The rotary motor of claim 39, wherein, for at least one vane rotor:

50. The rotary motor of claim 49, wherein:

51. The rotary motor of claim 39, wherein, for at least one vane rotor:

a radial extent of the motor space around that vane rotor from the inlet end to the discharge end is generally constant.

52. The rotary motor of claim 51, wherein:

53. The rotary motor of claim 39, wherein, for at least one vane rotor, each vane of that vane rotor is integrally formed with that vane rotor.

54. The rotary motor of claim 39, wherein, for at least one vane rotor, each vane of that vane rotor is connected to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

55. The rotary motor of claim 39, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

56. The rotary motor of claim 39, wherein, for at least one vane rotor, each vane of that vane rotor is held stationary relative to that vane rotor such that it does not move radially relative to that vane rotor a substantial amount.

57. The rotary motor of claim 39, further comprising:

a first gear associated with and rotationally fixed to the valve rotor; and