Abstract:
A light kit in combination with a pump system. The light kit includes a coil and a LED, where power produce by the coil when exposed to a rotating magnetic field powers the LEDs. The pump has a housing defining a pump interior, a driven magnet coupled to a pump impellor positioned in the pump interior, where the pump housing has an inlet and an outlet, and the is to be immersed in a fluid and to pump a fluid through the interior of the pump from the inlet to the outlet.

Description:
PRIORITY 
       [0001]    This application is a continuation of U.S. application Ser. No. 12/950,409 filed Nov. 19, 2010, and this application claims the priority benefit thereof, and which application is incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to magnetically driven centrifugal pumps, more particularly, lighting systems for magnetically driven centrifugal pumps. 
       BACKGROUND OF THE INVENTION 
       [0003]    Small pump applications, for instance for use in footspas or aquariums, generally are either propeller driven axial pumps, or centrifugal impeller type pumps. For purposes of this application, a “centrifugal pump” includes both propeller driven axial pumps, and an impeller and volute combination. The pump may be directly driven by a motor, or indirectly driven by the motor. In an indirect drive, the pump is mechanically isolated from the motor, but linked to the motor via magnetic forces. In a mechanically isolated pump, the driving forces to the pump are communicated via a driving magnet positioned on the motor, and a driven magnet positioned on the pump. Examples of this type of pump can be seen in U.S. Pat. No. 7,393,188 (hereby incorporated by reference), U.S. patent application Ser. No. 12/483,850 (hereby incorporated by reference), and Canadian application number 2706306 (hereby incorporated by reference). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a front perspective partially exploded view of one embodiment of the pump and light kit. 
           [0005]      FIG. 2  is a front perspective partially exploded view of one embodiment of the pump and light kit. 
           [0006]      FIG. 3A  is a front and rear view of one embodiment of the light kit. 
           [0007]      FIG. 3B  is a prospective view of a light kit housing. 
           [0008]      FIG. 4A  is a rear prospective view of one embodiment of the pump system. 
           [0009]      FIG. 4B  is a rear partially exploded view of the pump system of  FIG. 4A . 
           [0010]      FIG. 5  is a prospective view of a tank with an installed pump system of  FIG. 4A . 
           [0011]      FIG. 6  is a circuit diagram of one embodiment of the light kit. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0012]    Shown in  FIG. 1  is a mechanically isolated pump system, including a pump  10 , a motor  20 , and a light kit  30 . The shaft of the motor is not mechanically coupled to the pump, hence mechanically isolating the pump from the motor. The pump contains a pump housing, a driven magnet, and a pumping member coupled to the magnet (an impeller or propeller). See FIG. 4 of U.S. application Ser. No. 12/483,850, and FIG. 13C of Canadian application number 2706306. The motor  20  is coupled to a driving magnet, which is generally mounted on the motor shaft. See FIGS. 14B and 15B of Canadian application number 2706306. 
         [0013]    The motor is mounted adjacent to the exterior side wall of the spa basin, aquarium or other tank (such as shown in FIG. 3 of U.S. patent application Ser. No. 12/483,850) or FIGS. 14A and 14B of Canadian application number 2706306, thereby placing the driving magnet adjacent the tank exterior side wall. The pump is positioned in the interior of the tank near the motor, to place the driving magnet and driven magnet in close proximity in order to magnetically couple the two magnets. In many applications it is desired that the integrity of the tank not be compromised (such as in an aquarium), in which event, tank sidewall penetration to accommodate a motor or motor mount is not desired. In this event, the pump housing can positioned against the interior wall of the tank opposite the motor to magnetically couple the driving and driven magnet, providing motive power to the pump when the motor is operating (thereby activating the pump), such as shown in FIG. 3 of U.S. patent application Ser. No. 12/483,850. 
         [0014]    For many applications, such as in a foot spa, it is desired that the pump housing remain substantially stationary when the pump is activated. To minimize movement of the pump resulting from torque forces of the driven magnet and pumped fluid on the pump housing, the pump or pump housing can be mechanically coupled to the tank, tank sidewall, or other fixed point. For instance, the pump housing can be attached to an aeration device or other support, where the support is coupled to the tank. Alternatively, the pump housing may be held in place against a flange body that is fixedly attached to the interior tank wall (such as with epoxy, screws, etc.), or a flange body that is molded as a series of projections (or depressions) into the tank sidewall. Other mechanical coupling geometries or fixtures can be used to mechanically fix the position of the pump housing with respect to the interior wall of the tank or spa. 
         [0015]    Other means can be used to fix the pump housing in position. For instance, the tank sidewall may have an opening therethrough, and a sealing flange sealing the opening, such as described in Canadian patent application number 2706306. For the following description of the light kit, the pump  10  is mounted on a flange  21  that seals an opening in the tank sidewall, where the motor  20  is also coupled to the exterior facing portion of the flange  21 . However, the light kit  30  can be used with any type of pump mount, or mounted separate but adjacent to at least one of the driving or driven magnets, or mounted to the motor mount, if, for instance, the flange or tank sidewall is constructed from transparent or clear materials. 
         [0016]    As shown in  FIG. 2 , the sealing flange  21  includes projecting members  22  into which the pump  10  snaps via openings  15  on the rear face of the pump housing. Housing  10  snaps in place via matching slots in the rear of the pump housing. As shown in  FIG. 3B , light kit  10  includes a light kit housing  32  sealingly encompassing the electrical components. The light kit housing  32 , at least near the light emitting diodes (or other low power consumption light, all considered as LEDs), is transparent. In the embodiment shown, the light kit  30  is constructed from injection molded plastic. Light kit housing  32  may be fixedly attached to pump  10  (such as to the pump housing), the sealing flange  21 , the tank sidewall, or even the motor (if the tank or sealing flange is constructed of clear or transparent materials). Alternatively, as shown in  FIG. 2 , light kit  30  is sandwiched between the pump housing  10  and sealing flange  21 . The light kit housing has cutouts  33  to allow the kit  30  to be trapped between the sealing flange  21  and pump  10 , without fixedly attaching the light kit to either the sealing flange  21 , tank or pump  10 . Additionally, the housing may have a center opening  36  therethough to allow fluid to reach the rear of the pump to provide lubricity to a support bearing, as described in U.S. patent application Ser. No. 12/483,850. 
         [0017]    To enhance the light kit&#39;s effect, the pump housing is constructed of clear plastic. The light kit may also be built into the pump housing or the sealing flange. 
         [0018]    The basic electrical components of the light kit  10 , as shown in  FIG. 3A , include light emitting diodes or other low power consumption lights (hereafter “LEDs”)  100 , and a coil  110 , electrically connected to the LEDs. Additional electrical components (such as resisters and capacitors) may be needed to balance the circuit based upon the chosen coil (inductor) and LED characteristics. In operation, the coil is exposed to the magnetic field generated by the rotating driving and driven magnets, and hence an induced EMF is produced, generating an AC electrical current to power the LEDs. Preferably, the coil  110  is located in the high density magnetic flux region between the driving and driven magnets to allow for a smaller coil footprint. As shown in  FIG. 3A , the coil is positioned in a plane substantially parallel to the driving magnet and driven magnet, but may be positioned otherwise. 
         [0019]    Preferably, the driven and driving magnets are circular disk shaped magnets having at least one pair of magnetic poles (N) and (S), and constructed of high performance magnetic material offering low physical volume and high magnetic flux, such as neodynium materials. As the rotating poles of the magnets traverse the stationary coil or coils  100 , a current impulse is generated in the circuit due to the high magnetic flux density near the pole regions interacting with the coils. With rapid rotation, the LEDs appear to be powered by a fairly even power source, producing fairly consistent light emission from the LEDs. Magnets employing multiple domains, each with a set of poles, will increase the number of impulses per cycle, but the magnitude of the induced impulse current may be reduced as the magnetic regions are smaller and not creating the flux density of a single set of poles (as the time change in flux density induces the current, the larger the change, the greater the induced current). One embodiment uses a N42 neodynium iron boron magnet (NdFeB) having a single set of poles. 
         [0020]    The coil may generate sufficient current to power multiple LEDs, providing the option to control or sequence the powering of the LEDs, to create a desired effect. When multiple LED&#39;s are deployed in the light kit, a program chip controller  120  can be positioned in the circuit with imbedded programming for sequencing the powering of the LED&#39;s  110  connected to that controller  120 . With the inclusion of a controller  120 , rectifiers may be employed to provide DC power to the controller from the coils  110 . An example circuit using three coils and three LEDs is depicted in  FIG. 6 . As shown in  FIG. 6 , a single controller  120  is used to sequence the lighting of the LEDs, and transistors are employed to boost the current to the LEDs. Power to the controller is provided through voltage regulator  900  to condition the coil/rectifier produced power. In one embodiment, the light kit  20  includes three coils  110 , and fifteen total LEDs  100  of four colors (red, blue, white and green) (each LED being a 20 ma 4.8×4.4 mm straw hat LED lamp). The single controller  120  is used to sequence the powering of all the LEDs (for instance, power all red LEDs at once, followed by green LEDs; or powering red 1, then red 2, then red 3 around the perimeter of the kit, etc). Alternatively, multiple controllers could be used, each controlling a subset of the total LEDs in the light kit, such as depicted in  FIG. 3A . 
         [0021]    The coil characteristics needed will depend upon the strength of the magnetic field generated, the rotational speed of the motor, and the LED power requirements. To increase the inductance and hence induced EMF, iron or ferrite core inductors may be employed. 
         [0022]    As described, the light kit is positioned between the two magnets, but as mentioned, the kit may be mounted to the front of the pump housing, or positioned in front of the pump housing. The light kit may also be positioned on one side of the pump, however, the magnetic field strength is weaker at these locations, thereby requiring a larger coil, reduced power LED&#39;s or other means to deal with the reduced magnetic flux. The circuit components are preferably sealed in the light kit housing  32 , but may be only partially encased also (for instance, the diodes could be insertable into a sealing socket in the case). 
         [0023]    As described, the light kit is coupled to a pump mechanically isolated from the motor. The kit may also be used in a system where the pump is mechanically driven by the motor (e.g. the impellor or propeller is mechanically coupled to the motor shaft). In this instance, if the impellor or propeller is made of magnetic material, the pump system has a rotating magnet that can be used to power the light kit, such as by mounting the kit to the front of the housing in a fashion to avoid totally blocking the ports of the pump. With the present system, no external power is needed, and the system will not function unless the motor is operational. The device may include an on-off switch, preferably a switch sealed in the housing. Such a switch could be mechanical (e.g., a sealed switch push button or rocker switch accessible via a flexible sealing membrane on the housing, or could be radio controlled (which would operate when the device is powered via induced current)). The device may also be battery powered, but this is not preferred.