Abstract:
A magnetic drive, seal-less combination axial air and water pump includes a housing having an inlet and an outlet at least one impeller mounted for rotation within the housing, and a magnetic drive surrounding the first rotor and the second rotor, the magnetic drive being configured to transmit torque to the first rotor and a second rotor at a location radially spaced from a central axis of the first rotor and the second rotor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 62/201,367, filed on Aug. 5, 2015, which is herein incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to pumps and, more particularly, to a magnetic drive, seal-less, axial air and water pump. 
       BACKGROUND OF THE INVENTION 
       [0003]    Typical water pumps incorporate what is referred to as a “wet end” with an electric motor to produce water flow. The wet end consists of a centrifugal rotor contained within a plastic housing that diverts the water away from the rotor as it pumps outward from a linear feed flow to a centrifugal flow. The rotor is generally attached to the shaft of the motor, and the shaft is isolated from contact with the water within the pump by a compression wear seal that both seals the water inside the pump from leaking out of the pump, and provides a barrier to the water from reaching the shaft of the motor. In existing swimming pool and spa pump, the integrity of this seal may be compromised, requiring replacement or maintenance. Even if the seal does not fail outright and cause significant leakage through the seal, small leaks can form at the dynamic compression interface which, in turn, allows water to run down the shaft of the motor to the motor bearings. This can cause corrosion, which may be enhanced by the pool or spa chemicals, which can lead to motor failure. This type of leakage costs the pool and spa industries a lot of money in warranty service calls and pump replacements. 
         [0004]    Attempts have been made to eliminate these seals by attaching magnets to the shaft of the motor, and attaching magnets to the inside of a hollow shaft attached to the rotor. A sealed housing is placed between the two magnets, and the magnetic coupling between the two magnets cause the rotor to turn and pump water when the motor is activated. There are several issues with this type of design, however. For example, the pump is still a less efficient centrifugal type rotor arrangement, which requires significant torque to drive it effectively. Moreover, the surface area necessary for the magnetic coupling to turn the rotor is limited by the relatively small motor shaft diameters and the limits of how big the internal housing arrangement can be made to couple to the rotor. Ultimately, such design results in low transmitted torque values and, accordingly, underperformance in that they do not pump enough water nor produce enough pressure. 
         [0005]    Further solutions have involved the use of bigger motors, shafts and housings, the cost of which is typically too much to make them competitive with smaller, more powerful direct drive pumps with compression seals. 
         [0006]    In view of the above, there is a need for a seal-less water pump that rivals existing direct drive, seal-containing pumps in terms of performance and cost. 
       SUMMARY OF THE INVENTION 
       [0007]    It is an object of the present invention to provide a pump. 
         [0008]    It is another object of the present invention to provide a magnetic drive, seal-less, axial air and water pump. 
         [0009]    It is another object of the present invention to provide a magnetic drive, seal-less, axial air and water pump that rivals existing direct drive, seal-containing pumps in terms of performance and cost. 
         [0010]    These and other objects are achieved by the present invention. 
         [0011]    In an embodiment, a magnetic drive, seal-less combination axial air and water pump includes a housing having an inlet and an outlet at least one impeller mounted for rotation within the housing, and a magnetic drive surrounding the first rotor and the second rotor, the magnetic drive being configured to transmit torque to the first rotor and a second rotor at a location radially spaced from a central axis of the first rotor and the second rotor. 
         [0012]    In another embodiment, a method of pumping a fluid includes the steps of arranging at least one rotor interior to a pump housing, surrounding the at least one rotor with a magnetic drive assembly, the magnetic drive assembly including a generally cylindrical inner array of magnets encompassing the at least one rotor and a generally cylindrical outer array of magnets surrounding the inner array, coupling an inlet of the housing to a source of fluid, and transmitting torque to the at least one rotor at a location radially spaced from a longitudinal axis of the at least one rotor. 
         [0013]    In yet another embodiment, a magnetic drive, seal-less, axial pump includes a generally cylindrical housing having an inlet and an outlet, at least one impeller mounted for rotation within the housing, and a magnetic drive surrounding the first rotor and the second rotor, the magnetic drive being configured to transmit torque to an outer portion of the at least impeller at a location spaced radially from a longitudinal axis of the housing for rotating the impeller. The magnetic drive includes an inner magnetic array positioned interior to the housing and a outer magnetic array positioned exterior to the wall of the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below: 
           [0015]      FIG. 1  is a perspective view of a pump according to an embodiment of the present invention. 
           [0016]      FIG. 2  is a perspective view of a housing of the pump of  FIG. 1 . 
           [0017]      FIG. 3  is a longitudinal, cross-sectional view of the pump of  FIG. 1 . 
           [0018]      FIG. 4  is an axial, cross-sectional view of the pump of  FIG. 1 , showing an air rotor thereof. 
           [0019]      FIG. 5  is another axial, cross-sectional view of the pump of  FIG. 1 , showing a water rotor thereof. 
           [0020]      FIG. 6  is an axial, cross-sectional view showing an inner magnetic array of the pump of  FIG. 1 . 
           [0021]      FIG. 7  is a perspective view of a combination air and water rotor of the pump of  FIG. 1 . 
           [0022]      FIG. 8  is a detail perspective view of the water rotor of the combination air and water rotor of  FIG. 7 . 
           [0023]      FIG. 9  is a detail perspective view of the air rotor of the combination air and water rotor of  FIG. 7 . 
           [0024]      FIG. 10  is a perspective view of a double air rotor, according to an embodiment of the present invention. 
           [0025]      FIG. 11  is a perspective view of a double water rotor according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    Referring to  FIGS. 1-3 , the present invention relates to a magnetic drive, seal-less combination axial air and water pump  10 . As shown therein, the pump  10  includes a housing  12  having an inlet  14  for accepting a linear flow of a fluid therethrough, and an outlet  16  for discharging the fluid at high pressure. The housing  12  is integrated with an external magnetic drive mechanism that includes an inner magnetic array  18  positioned within the housing and having a plurality of magnets, and an outer magnetic array  20  positioned outside the housing and surrounding the housing and having a plurality of magnets. As shown therein, the inner and outer magnetic array  18 ,  20  may be of a substantially cylindrical shape and dimensioned to correspond to the length, shape and diameter of the housing  12 . In particular, in an embodiment, the inner magnetic array  18  is generally cylindrical in shape, has an outside diameter that corresponds closely to the inner diameter of the housing, and has a length that corresponds to the approximate length of the pump housing. Likewise, the outer magnetic array  20  is generally cylindrical in shape, has an inside diameter that corresponds closely to the outside diameter of the housing, and has a length that corresponds to the approximate length of the pump housing. As shown in  FIG. 1  the pump  10  is coupled to and surrounded by a hollow core motor  11  of any type known in the art, which is configured to drive the magnetic drive. 
         [0027]    As best illustrated in  FIG. 3 , a plurality of impellers or turbines, referred to herein as a water rotor  22  and an air rotor  24 , are mounted for rotation within the housing  12 , interior to the inner magnetic array  18 . In the preferred embodiment, the air rotor  24  is positioned within the housing  12  generally adjacent the outlet  16  while the water rotor  22  is positioned within the housing  12  axially closer to the inlet  12  than the air rotor  24 . 
         [0028]      FIGS. 8 and 9  illustrate the configuration of the water rotor  22  and the air rotor  24 , respectively. As shown therein, each rotor  22 ,  24  has a generally hollow, cylindrical shaft  26  on which a plurality of blades are carried. As shown therein, the water rotor  22  has three blades  28  mounted to the shaft  26  while the air rotor has six blades  30  mounted to the shaft  26 . The blades  28  of the water rotor  22  each take up a greater portion of the circumference of the shaft than do the blade  30  of the air rotor  24 . 
         [0029]    In operation, the external magnetic drive mechanism that surrounds the rotors transmits torque to the outside of the rotors, rather than to the center-line shaft of the rotor, thus allowing for the generation of much higher transmitted torques than has heretofore been possible. This arrangement of the magnets in an external array allows for the placement of many more coupling magnets about an order of magnitude more coupling area than can be achieved by the prior art. This increase in coupling area results in significantly more torque transmitted to the rotors and allows for higher outputs and more pressure for the pump. 
         [0030]    Although this external coupling mechanism can be utilized to power standard centrifugal pumps, it allows for much a more efficient straight through linear pump design such as that described herein. Using a hollow core electric motor to power the external magnetic coupling mechanism allows for the provision of a straight-through linear pumping system. The pump  10  of the present invention is much more energy efficient than centrifugal pumps and needs far less toque to run it efficiently. This fact, coupled with the enhanced torque produced by the external magnetic coupling mechanism, allows the pump of the present invention to far outperform any magnet-driven pumps of similar size. 
         [0031]    In addition to the above, the pump  10  of the present invention allows for a completely seal-less pumping system for use in swimming pools, spas, and other applications where seal leakage can lead to failure of the pumps. Because the pump is linear, multiple rotors can be easily incorporated into the design to produce higher and more efficient outputs. In addition to multiple rotors for pumping water, turbo rotors for pumping air can also be incorporated to form a very efficient air pump. Moreover, in addition to air and water pumps, multiple mixed rotors can be added to the same shaft so that the linear pump is capable of pumping either water or air, or a combination of both. 
         [0032]    For example, in an embodiment, a combination rotor  40  having a water rotor  22  and an air rotor  24  may be utilized within the pump  10  for pumping both air and water, as illustrated in  FIG. 9 . This is useful, for example, for inflatable spas where one pump can be used to inflate the spa and then pump the water for that spa with the same pump. Additional air inlets can be opened to allow air into the pump where the combination of rotors will pump and mix the air and water to form aerated water for the spa jets. This capability will allow for the elimination of a separate blower unit for spas. 
         [0033]    Alternatively, a double air rotor  50  having dual air rotors  24 , as shown in  FIG. 10 , may be utilized for pumping just air, while a double water rotor  60  having dual water rotors  22 , as shown in  FIG. 11 , may be utilized for pumping just water. 
         [0034]    As indicated above, the present invention therefore allows for the production of a high torque, magnetic drive unit for swimming pool and spa pumps. The linear drive, linear flow-through pump of the present invention is capable of pumping both air and water, or a combination of the two, which provides a level of versatility heretofore not seen in the art. As discussed above, this obviates the need to utilize two separate pumps for air and water. Moreover, the pump, when coupled with a hollow core electric motor, provides a compact and simplified pumping system that is energy efficient, easily scalable to higher outputs, and can be used to pump both liquid and air. 
         [0035]    As further discussed above, the pump  10  of the present invention does not utilize seals, which allows if to be used not only for the pumping of water and air over a very long life, but also for other applications such as the pumping of corrosive liquids of any kind. Indeed, while the present invention has been described herein as being utilized to pump air and water, the present invention is not intended to be limited in this regard. In particular, because there are no seals, the pump may be utilized to pump any fluid, including corrosive liquids. In stainless steel configurations, the pump  10  may be utilized as an emulsifying pumping system for the food and chemical industries. 
         [0036]    It is also contemplated that the pump may be manufactured in a variety of geometries to suit any specific application, such as long and skinny, short and wide, etc. 
         [0037]    In yet another embodiment, the pump  10  may utilize the magnetic stator of an induction motor to produce the rotating magnetic driving field like that in an induction motor. In particular, in an embodiment this rotating field is coupled to rotating magnets similar to the inner and outer magnetic arrays described above that provide the poles to be drive by the stator. This spins the rotors within the pump housing just as if it were a motor winding, but it is all sealed in the housing, as discussed above. 
         [0038]    Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of this disclosure.