Patent Abstract:
Fluid-powered devices are detailed. The devices may be utilized as motors or pumps, for example, and are capable to switching dynamically between these functions. They additionally may use surface-area, rather than solely pressure, differentials to produce rotary motion.

Full Description:
REFERENCE TO PROVISIONAL APPLICATION 
     This application is based on, claims priority to, and hereby refers to U.S. Provisional Patent Application Ser. No. 61/192,927, filed Sep. 23, 2008, entitled “Fluid Powered Motor and Pump,” the entire contents of which are incorporated herein by this reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to fluid-powered motors and pumps and more particularly, but not necessarily exclusively, to motors and pumps powered by (or powering) liquids such as water. The motors and pumps may be especially useful in connection with filtration systems for pools and spas, although they may be used in other ways as well. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 4,449,265 to Hoy illustrates an example of a wheeled automatic swimming pool cleaner. Powering the wheels is an impeller comprising an impeller member and pairs of vanes. Evacuating the impeller causes water within a swimming pool to interact with the vanes, rotating the impeller member. The impeller is reversible, with the impeller member apparently moving laterally when the pool cleaner reaches an edge of a pool to effect the rotation reversal. 
     U.S. Pat. No. 6,292,970 to Rief, et al., describes a turbine-driven automatic pool cleaner. The cleaner includes a turbine housing defining a water-flow chamber in which a rotor is positioned. Also included are a series of vanes pivotally connected to the rotor. Water interacting with the vanes rotates the rotor in one direction (clockwise as illustrated in the Rief patent), with the vanes pivoting when encountering “debris of substantial size” to allow the debris to pass through the housing for collection. The contents of the Hoy and Rief patents are incorporated herein in their entireties by this reference. 
     SUMMARY OF THE INVENTION 
     The present invention provides efficient alternatives to conventional impellers and turbines. The invention also may be activated as a pump and, if desired, may switch between motor and pump functions dynamically. It has especial usefulness as a motor powering an automatic swimming pool cleaner, although the invention may be utilized in connection with other aspects of a filtration system for a pool or spa or as part of any other system in which conversion of energy from, for example, a suction or pressure source to rotational power is necessary or desired. 
     Currently-preferred versions of the present invention typically comprise a body having at least one inlet and at least one outlet. Within the body are positioned one or more pairs of paddles whose distal edges may, if desired, be locally flexible to facilitate passage of debris. Such local flexibility is not required, however. Rather than being placed in the same plane (or otherwise uniformly formed), however, paddles of a pair in the present invention may be positioned perpendicularly. Stated differently, if the paddles themselves are generally planar and one paddle of a pair exists in a first plane, the other paddle of the pair may exist in a second plane normal to the first plane. In other versions these paddles of a pair need not necessarily be perpendicular to each other, although some angular difference between orientations of paddles of a pair may be beneficial. In yet other versions, paddles need not necessarily be paired, although again having angular differences between orientations of various paddles may be advantageous. 
     In at least one version of the invention having paired paddles, a first pair of paddles is connected by a shaft. The paddles additionally are connected, via hinges, bearings, or other connection means, to a base. The base is configured to allow some rotation of the paddles about an axis aligned with at least part of the shaft, with the base and connection means also functioning to limit rotation of the paddles in some, but not all, versions of the invention. Preferably, the paddles may rotate through an angle of ninety degrees about this axis, although other angular rotations may occur instead. 
     At least this embodiment further includes a second pair of paddles likewise connected by a shaft and to a base. Each of the two shafts beneficially may be non-linear, allowing the shafts to cross without interfering with paddle rotation yet permitting portions of each shaft to remain in the same plane. Moreover, the two bases may be configured to fit together, forming a unitary structure housing at least parts of both shafts. Either or both bases may include an outwardly-extending shaft that provides (1) rotational output when the invention is used as a motor and (2) rotational input when the invention is used as a pump. 
     Bodies consistent with the invention may be hollow (or have hollow portions) into which the paddles and bases are fitted. The unitary structure including the paddles and bases may rotate about the outwardly-extending shaft (or shafts) a full three hundred sixty degrees (i.e. in paddle-wheel fashion) either clockwise or counter-clockwise as desired. Consequently, paddles of the present invention may rotate about two different axes in operation, although they preferably do not move linearly—unlike the impeller member of the Hoy patent. 
     The bodies also may be configured to present flow restrictions. Such a restriction may, when contacted by a paddle, cause the paddle to rotate so that its faces are parallel (or generally parallel) to the fluid direction through the body. This rotation in turn causes the paired paddle to rotate so that its faces are perpendicular to the flow direction. The result is one paddle of a pair presenting minimum surface area to the flow direction while the other provides maximum surface are to the flow direction, allowing the suction or pressure force to work with greatest efficiency in rotating the unitary structure to supply high-torque output. 
     Stated differently, the present invention uses predominantly surface-area differentials to cause rotary motion. The fluid-flow pressure encountered by both paddles of a pair is the same (or approximately so); one paddle merely presents a larger surface area to the fluid flow than does the other paddle. This concept differs significantly from that of standard impellers, which jet fluid at one side of an impeller to cause a pressure differential on sides of the blades, thus creating rotation to relieve the imbalance. 
     Moreover, in standard impellers, a blade opposite the one being impacted by the jetted fluid is moving fluid in a direction opposite the flow. In this sense, it is “dragging dead fluid” along, reducing the overall efficiency of the device. By contrast, no material level of such “dragging” occurs in connection with the present invention. 
     It thus is an optional, non-exclusive object of the present invention to provide fluid-powered devices that may be employed as motors or pumps (or both). 
     It is another optional, non-exclusive object of the present invention to provide fluid-powered devices using, predominantly or exclusively, surface-area differentials to cause rotary motion. 
     It is a further optional, non-exclusive object of the present invention to provide fluid-powered devices utilizing at least one pair of paddles, with each paddle of a pair being non-planar, or otherwise non-uniformly oriented, with the other paddle of the pair. 
     It is, moreover, an optional, non-exclusive object of the present invention to provide paddles configured to rotate about multiple axes. 
     It is also an optional, non-exclusive object of the present invention to provide fluid-powered devices having a pair of paddles connected via a non-linear shaft. 
     It is an additional optional, non-exclusive object of the present invention to provide fluid-powered devices especially useful in connection with automatic swimming pool cleaners or other equipment used as part of filtration systems of pools, spas, or hot tubs. 
     Other objects, features, and advantages of the present invention will be apparent to those skilled in appropriate fields with reference to the remaining text and the drawings of this application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a first exterior plan view of an exemplary device consistent with the present invention. 
         FIG. 2  is a second exterior plan view of the device of  FIG. 1 . 
         FIG. 3  is a first perspective view of portions of the device of  FIG. 1 , including two pairs of paddles and a flow restrictor depicted within a body. 
         FIG. 4  is a second perspective view of portions of the device of  FIG. 1 , including the pairs of paddles of  FIG. 3 . 
         FIG. 5  is a perspective view of the pairs of paddles of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
     Depicted in  FIGS. 1-2  is exemplary device  10 . Device  10  may function as a motor or pump or as any other device configured to convert energy from a suction or pressure source to rotational movement. Device  10  may include body  14  defining inlet  18  and outlet  22  as well as outwardly-extending shafts  26 . Although two such outwardly-extending shafts  26  are illustrated in  FIGS. 1-2 , more or fewer shafts  26  may be utilized instead. Likewise, although shafts  26  are shown in  FIGS. 1-2  as being elongated rods, they may be configured or shaped differently than as shown. 
     Body  14  may, if desired, comprise at least first and second portions  30  and  34 . If so, first and second portions  30  and  34  preferably are connected in use, as illustrated in  FIGS. 1-2 . At least part of body  14  additionally preferably (although not necessarily) is symmetric about both (1) the connection between first and second portions  30  and  34  and (2) an axis coincident with shafts  26 . Fluid flow through body  14  may occur from inlet  18  to outlet  22  or from outlet  22  to inlet  18 . Hence, the terms “inlet” and “outlet” of body  14  are used herein for convenience, as the “inlet” may at times be the outlet of body  14  and the “outlet” may at these times be the inlet of body  14 . 
     Also depicted in  FIGS. 1-2  as being within body  14  is an exemplary blade, vane, or paddle  38  as well as restriction  42  and hubs or bases  46 A and  46 B. Paddle  38 , together with one or more similar paddles, may be connected directly or indirectly to outwardly-extending shafts  26 . When device  10  is employed as a motor, fluid flowing through body  14  interacts with each paddle  38  to produce rotation of shafts  26 . 
       FIGS. 3-5  depict multiple paddles  38 .  FIG. 5 , in particular, illustrates that paddles  38  may, if desired, be paired; two such pairs are shown in the figure, with one pair comprising paddles  38 A and  38 B and the other pair comprising paddles  38 C and  38 D. In presently-preferred versions of device  10 , paddles  38 A and  38 B are connected by shaft  50 A and paddles  38 C and  38 D are connected by shaft  50 B. Preferably no direct connection exists between paddles  38 A and  38 B, on the one hand, and paddles  38 C and  38 D, on the other hand. Instead, shafts  50 A and  50 B are configured to cross in a manner avoiding interference by shaft  50 A with rotation of paddles  38 C and  38 D and by shaft  50 B with rotation of paddles  38 A and  38 B. Although device  10  preferably includes four paddles  38  (e.g. paddles  38 A,  38 B,  38 C, and  38 D), more or fewer paddles  38  may be used. 
     In a version of paddles  38  depicted in  FIGS. 3-5 , shaft  50 A resembles an elongated cylinder and thus may define a generally longitudinal axis X. Shaft  50 B is similar, defining a generally longitudinal axis Y. Central portion  54 A of shaft  50 A, however, deviates from axis X, essentially being shifted laterally from the axis X to form nesting space  58 A. Likewise, central portion  54 B of shaft  50 B is translated from axis Y to form nesting space  58 B. Shaft  50 A thus may be placed generally in the same plane as shaft  50 B, with nesting spaces  58 A and  58 B being adjacent. In the version shown in  FIG. 5 , central portion  54 A is atop central portion  54 B but not in contact therewith because of the alignment of nesting spaces  58 A and  58 B. 
       FIG. 5  additionally illustrates a preferred relative orientation of paddles  38  of a pair. Paddle  38 A, for example, is shown in  FIG. 5  as having a principal face  62  (together with its opposite face, which is not shown) generally in the plane of the page. By contrast, paddle  38 B is depicted as having its principal and opposite face  66  (as well as its unshown opposite face) generally normal to the plane of the page. Stated differently, a plane containing principal face  62  and passing through axis X preferably is perpendicular to a plane containing principal face  66  and passing through axis X, so that principal faces  62  and  66  are offset by ninety degrees. Accordingly, when principal face  62  presents maximum surface area to the flow direction through body  14 , principal face  66  will present minimum surface area to the flow direction. Relative orientation of paddles  38 C and  38 D preferably is similar; a plane containing principal face  70  of paddle  38 D passing through axis Y may be perpendicular to a plane containing principal and opposite faces  74  and  78 , respectively, of paddle  38 C passing through the axis Y. 
     Although relative faces of pairs of paddles  38  preferably are offset by ninety degrees, this exact angular orientation is not mandatory. Angular offset should be greater than zero for paddles  38  of a pair; thus the invention contemplates any other such offset. Nevertheless, offsets greater than, for example, five, twenty, or forty-five degrees may be necessary to produce satisfactory results in many cases. Because preferred versions of shafts  50 A and  50 B and faces  62 ,  66 ,  70 ,  74 , and  78  (etc.) are inflexible, paddles  38 A and  38 B will retain their angular offset at all times, while paddles  38 C and  38 D likewise will retain their angular offset at all times. If desired, however, paddle edges (such as edge  82  of paddle  38 A) may be flexible to facilitate passage of debris through body  14  or reduce frictional wear of paddles  38  (or of body  14 ). 
     Shafts  50 A and  50 B, together with bearings-containing wheels  86 , may be placed in base  46 B as illustrated in  FIG. 3 . Base  46 A ( FIG. 4 ) may be fitted over wheels  86  and attached to base  46 A. The resulting structure permits shafts  50 A and  50 B and associated paddles  38 A-D to rotate about axis Z coincident with shafts  26 . When device  10  functions as a motor, rotation about axis Z occurs because of fluid flow through body  14 ; if fluid enters via inlet  18 , rotation will be in the direction of arrow A (see  FIG. 3 ). Conversely, if fluid enters via outlet  22 , rotation will be in the opposite direction, as shown by arrow B. (Alternatively, restriction  42  may be repositioned appropriately within body  14  to reverse rotational direction without changing whether fluid enters via inlet  18  or outlet  22 .) Because shafts  26  are connected to the rotating components, they too will rotate, providing power available to perform useful work. 
     In use, paddles  38  rotate about another axis as well. Paddles  38 A-B, for example, may rotate about axis X, while paddles  38 C-D may rotate about axis Y. This second type of rotation is caused by restrictor  42 . 
     Assume, for example, that paddles  38 A-D are configured and oriented as shown in  FIG. 3  and rotating in the direction of arrow A. Paddle  38 C is generally vertical in this example as it approaches restrictor  42 , which is shown as being in the form of a ramp. Further movement in the direction of arrow A causes face  78  of paddle  38 C to contact restrictor  42 , whose sloping surface  90  (see also  FIG. 2 ) forces paddle  38 C to rotate about axis Y so as to reorient generally horizontally (with its face  74  ultimately facing upward like face  62  in  FIG. 3 ). As paddle  38 C rotates from a generally vertical position to a generally horizontal one, paired paddle  38 D will rotate from a generally horizontal position to a generally vertical one. Indeed, this relationship is illustrated in  FIG. 3  by paired paddles  38 A and  38 B: Paddle  38 A has already been forced by restrictor  42  into a generally horizontal orientation, causing paired paddle  38 B to assume a generally vertical orientation. 
     Continuing this example consistent with  FIG. 3 , fluid entering inlet  18  may travel to outlet  22  via either side of base  46 B—i.e. through both channel  94  and channel  98 . (Preferably, however, channel  98  is substantially more restricted than channel  94 , so that only limited flow occurs therethrough.) The fluid entering inlet  18  initially encounters paddle  38 D. Because paddle  38 D is generally horizontal, it presents minimal surface area to the direction of fluid flow from inlet  18  to outlet  22 . This result additionally is true for paddle  38 A, having been forced to the horizontal position by restriction  42  (and in effect sealing, or substantially sealing, channel  98 ). By contrast, paddle  38 B is generally vertical, presenting maximum surface area (in the form of face  66 , which is not shown in  FIG. 3  but is depicted in  FIG. 5 ) to the fluid flow direction. This differential surface area causes the flowing fluid to push on paddle  38 B, resulting in paddle rotation in the direction of arrow A. 
     Although not illustrated in  FIG. 3 , restrictor  42  may continue throughout channel  98  or otherwise have a sloping surface adjacent inlet  18 , so that device  10  may be operated in reverse. Further, if power is supplied to rotate one or more shafts  26 , the shafts  26  in turn may rotate paddles  38  about axis Z so that device  10  may function as a fluid pump, in this sense being fluid “powered” in its operation regardless of how shafts  26  are caused to rotate. As a consequence, device  10  provides a versatile, efficient mechanism for using flowing fluid to create rotation. 
     The foregoing is provided for purposes of illustrating, explaining, and describing embodiments of the present invention. Modifications and adaptations to these embodiments will be apparent to those skilled in the art and may be made without departing from the scope or spirit of the invention.

Technology Classification (CPC): 5