Abstract:
An injection molded commercial pool pump is provided having a motor, an adapter plate connected to the motor, a housing connected to the adapter plate further comprising a channel, a sealing plate positioned between the adapter plate and housing, an impeller connected to the motor shaft, an o-ring positioned between the sealing plate and housing to prevent leaking of internal fluids and a diffuser positioned over the impeller and connected to the sealing plate where the diffuser and impeller are inserted into the channel.

Description:
This application claims the benefit of U.S. Provisional Patent Application No. 60/537,537 filed on Jan. 20, 2004. 

   FIELD OF THE INVENTION 
   The present invention relates to a commercial pool pump and more specifically to a partially injection molded pool pump assembly for use in large commercial pool applications. 
   BACKGROUND OF THE INVENTION 
   The commercial swimming pool pump market is defined by size, typically ranging from 5 HP to 25 HP. Previously, manufacturing a commercial swimming pool pump using an injection molding process was not practical due the relatively small market size, the capital investment required, and the technical challenges involved in commercializing an injection molded pump of suitable size. Commercial swimming pool pumps are typically constructed of either cast iron or cast bronze that weigh between 300-500 pounds. One disadvantage of commercial pumps is that they normally require special equipment such as a hoist or lift truck to install or replace the pumps. This is especially important when replacing pumps in an existing installation where access by a lift truck is no longer practical without removing facility doors or walls. Another disadvantage of commercial pumps is that they can be susceptible to corrosion, which can cause vital pump components to fail and ultimately shutting down the pump and the pool. In addition, the corroding components deposit chemical materials into the water where they come into contact with the swimmers. Furthermore, the corroding components can deposit permanent chemical stains on the pool walls. 
   Another disadvantage of cast pumps is that the cast components are cast to a rough size and finish. Therefore, cast components require additional machining to shape and finish the components. Whereas, injection molded components are molded to the correct size and finish. 
   Still another disadvantage of cast pumps is the inherent defects that are present in the metal casting process. These defects include pinholes, poor surface finish, and rapid surface oxidation. Typically, cast components are reworked to repair these defects thereby adding cost to the manufacture of such pumps. In addition, detection of pinhole leaks does not typically occur until the pump is in operation thus requiring the pump and pool to shut down during repair. 
   In order to overcome the above mentioned disadvantages, commercial swimming pools typically utilized multiple small, injection molded, residential pumps, usually limited to 3 HP, to obtain the benefit of using a light weight, corrosive resistant pump. However, the costs associated with installing and maintaining multiple pumps were not cost effective. 
   In addition, one challenge in manufacturing large injection molded parts is the difficulty in molding an open end of a large cylindrical shaped part with a high degree of roundness. Another challenge is that it is difficult to mold a flat plate type geometric shape such as a pump seal plate to a controlled tolerance of flatness. These geometric shapes tend to move during operation of the pump due to the stresses on the seal plate and housing cylinder. 
   The present invention overcomes the above mentioned disadvantages by providing a specially geometrically designed pump that is primarily manufactured using an injection molded process. 
   BRIEF SUMMARY OF THE INVENTION 
   In accordance with one aspect, the present invention overcomes the above mentioned disadvantages by providing an injection molded commercial pool pump comprising, a motor with a rotating shaft, an adapter plate connected to the motor, a housing connected to the adapter plate further comprising a channel having a first and second end, a sealing means positioned between the adapter plate and housing, and an impeller connected to the motor shaft and where the impeller resides in the channel. 
   In accordance with another aspect, the present invention provides an injection molded commercial pool pump comprising, a housing having a tapered inlet channel and an outlet channel having a bottom portion, a basket having a bottom positioned in the housing, a securing means to secure the basket in the housing, where the bottom of the basket is above the bottom portion of the outlet channel thereby forming a chamber at the bottom of the housing. 
   Additional benefits and advantages of the present invention will become apparent to those skilled in the art to which it pertains upon a reading and understanding of the following detailed specification. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may take physical form in certain parts and arrangement of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings that form a part of the specification. 
       FIG. 1  is an exploded view of a pump assembly according to one embodiment of the invention; 
       FIG. 2  is across-sectional view of the pump assembly in its assembled state; 
       FIG. 3  is a top view of the pump assembly; 
       FIG. 4  is an exploded view of a modular pre-pump filter according to one embodiment of the invention; 
       FIG. 5  is a cross-sectional view of the modular pre-pump filter in its assembled state; 
       FIG. 6  is a side view of the modular pre-pump filter in its assembled state; 
       FIG. 7  is a front view of the intake flange; and 
       FIG. 8  is a top view of the modular pre-pump filter. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings,  FIGS. 1 and 4  show two main assemblies of an injection molded pump.  FIG. 1  shows a pump assembly  10  and  FIG. 4  shows a modular pre-pump filter assembly  60 . The pump assembly  10  will be subsequently described and the modular pre-pump assembly  60  will be described in detail further below. 
   Referring to  FIGS. 1-3 ,  FIG. 1  shows an exploded view of the pump assembly  10 . The main components of the pump assembly  10  include a motor  12  having a rotatable shaft  11 , an adaptor plate  14 , a seal plate  16 , a seal plate o-ring  18 , an impeller  20 , a diffuser  22  adjacent to the impeller  20 , a diffuser o-ring  24 , and a pump housing  26 . The motor  12  can be, for example, an electric motor having a suitable size and power such as many commonly known in the art and will not be described in further detail. The combination adapter plate  14  and seal plate  16  provide a unique seal arrangement to both increase strength and reduce stress between the pump housing  26  and the motor  12 . The adaptor plate  14  attaches to the motor  12  with bolts  28  and transfers pressure created by the pump assembly  10  to the steel frame of the motor  12  thereby reducing deflection in the seal plate  16 . The adapter plate  14  includes multiple holes  15  to assemble the pump assembly  10  as will be described below. The seal plate  16  also includes multiple holes  17  that line up with the holes  15  on the adapter plate  14  to connect the adapter plate  14  to the pump housing  26 . The seal plate  16  further secures the seal plate o-ring  18  to the pump housing  26 . The seal plate o-ring  18  prevents internal fluid of the pump assembly from escaping during operation of the pump assembly  10 . Furthermore, as previously mentioned, when injection molding large, flat, plate type components controlling the tolerance of flatness can be a difficult challenge. Therefore, the adapter plate  14  and the seal plate  16  are designed such that they can be manufactured using a simple injection molding process. More specifically, the thickness of the adapter plate  14  and the seal plate  16  are such that they can be manufactured having an acceptable tolerance of flatness. 
   Still referring to  FIGS. 1-3 , the pump housing  26  further includes a first opening  32 , a second opening  33 , a sealing flange  34  with holes  35  to mate with the seal plate  16 , an intake flange  36  to mate with the modular pre-pump filter  60 , a ridge  38  located on the intake flange  36 , an outlet channel  40  and an outlet flange  42 . The pump housing  26  has an eccentric geometric design that facilitates the injection molding process, assembly and operation of the pump assembly  10 . As shown in  FIG. 2 , when assembled, the centerline  27  of the pump housing  26  can be located above the centerline  13  of the motor  12  thereby creating a larger volume above the diffuser  22  than below the diffuser  22 . This design raises the primer water level such that the pump assembly  10  functions as a self-priming pump when connected to the modular pre-pump filter  60 . Furthermore, the eccentric design eliminates the need for complicated injection molding tooling to form an internal chamber normally required for priming a pump. It should be noted that the embodiment shown in  FIG. 2  is for illustration purposes only and is not intended to limit the scope of the invention. For example, the centerline  13  of the motor and the centerline  27  of the pump housing  26  can be on the same horizontal plane. 
   Referring to  FIG. 2 , the impeller  20  is located in the pump housing  26  and attaches to the motor shaft  11 . In addition, the impeller  20  can be located at any position along the centerline  13  of the motor  12 . For example, in the embodiment shown the impeller  20  is positioned adjacent to the first opening  32  and not directly beneath the outlet channel  40 . This design allows for a high capacity low head performance. Furthermore, the impeller  20  can be made from an injection molding process therefore, giving it a smaller rotating mass than the traditional commercial impellers. This greatly reduces the weight of the impeller  20  and thus reduces the start-up and operating electrical loads of the motor  12 . 
   The intake flange  36  further includes ribs  44  located on the inside face  46  to provide strength to the intake flange  36 . Holes  48  are provided on the intake flange  36  to either mate the pump housing  26  to an end user supplied standard flange or to the modular pre-pump filter  60 . Metal inserts (not shown) can be provided in the holes  48  for reinforcement. The ridge  38  on the intake flange  36  receives an o-ring  72  (shown in  FIG. 4 ) to seal the pump housing  26  to the modular pre-pump filter  60 . 
   The outlet channel  40  extends in an upward direction and further includes reinforcing ribs  41  to provide support during operation of the pump assembly  10 . The outlet channel  40  can be located at any position between the first  32  and second  33  openings. For example, in the embodiment shown the outlet channel  40  is adjacent to the second opening  33 . The outlet flange  42  can be an industry standard flange that further includes a unique ribbed surface  43  to provide an optimal seal. 
   The adapter plate  14 , seal plate  16 , and the pump housing  26  are connected using multiple bolts  50  as illustrated in  FIG. 1 . This type of connection and design allows the seal plate  16  to retain a sufficient flatness during operation of the pump assembly  10 . Furthermore, under vacuum conditions, the seal plate o-ring  18  is pulled into the gap between the seal plate  18  and the pump housing  26  thereby sealing the joint between them. 
   Referring to  FIGS. 4-8 ,  FIG. 4  shows an exploded view of the modular pre-pump filter  60  commonly referred to in the art as a strainer pot. The modular pre-pump filter  60  includes a pre-filter housing  62 , a pre-filter basket  74 , an o-ring  76 , a lid  78 , and a locking ring  90 . The pre-filter housing  62  can be a fully integrated component and includes a top opening  63 , a tapered intake channel  64 , an intake flange  66 , an outlet channel  68 , an outlet flange  70 , ridges  71  around the top opening  63 , and an outlet o-ring  72 . As shown in  FIGS. 4 and 6 , integrated ribs  67  can be provided at the back of both the intake flange  66  and outlet flange  70  to provide reinforcement and to transfer heavy piping loads that occur at the flange  66 ,  70  connections. Because both the intake flange  66  and the outlet flange  70  can be industry standard flanges the modular pre-pump filter  60  can either be manufactured as an integral portion of the pump assembly  10  or can be installed as a separate modular unit. As shown in  FIGS. 4 and 7 , the intake flange  66  includes a unique ribbed surface  67  to provide an optimal seal. 
   The pre-filter basket  74  can be made of a non-corrosive plastic material. Previous commercial swimming pool pumps utilized a stainless steel or a stainless steel/brass casting construction for the pre-filter basket  74 . These baskets had two disadvantages: 1) they were susceptible to corrosion and 2) they were difficult to handle by the user. The pre-filter basket  74  overcomes these disadvantages by providing a lightweight basket with an integrated handle (not shown) for ease in handling. 
   Referring to  FIG. 5 , a unique feature of the modular pre-pump filter  60  is that the pre-filter basket  74  can be positioned in the pre-filter housing  62  at any point between the intake channel  64  and the outlet channel  68 . More specifically, the pre-filter basket  74  can be eccentrically positioned within the pre-filter housing  62 . For example, in the embodiment shown the pre-pump filter is positioned closer to the intake channel  64  than to the outlet channel  68 . This feature allows the pre-filter basket  74  to filter a significant portion of the debris without the pump assembly  10  experiencing any cavitation or loss of head capacity performance. 
   Another unique feature of the modular pre-pump filter  60  is that the pre-filter basket  74  can be located at any vertical position within the pre-filter housing  62 . In other words, the bottom  82  of the pre-filter basket  74  can either rest on the bottom  88  of the pre-filter housing  62  or can be positioned a distance from the bottom  88  of the pre-filter housing  62 . For example, in the embodiment shown, the pre-filter basket  74  is positioned above the bottom  84  of the outlet channel  68  to form a chamber  86  in the pre-filter housing  62  below the pre-filter basket  74 . This feature allows heavy debris, such as metal objects or stones, to pass through openings (not shown) in the bottom  82  of the pre-filter basket  74  and settle in the chamber  86 . The chamber  86  is designed to provide a dead flow zone in the modular pre-pump filter  60  thus preventing any debris that settles in the chamber  86  from passing through the modular pre-pump filter  60  and into the impeller  20 . 
   Referring to  FIGS. 4 and 8 , the lid  78  and locking ring  90  are unique in that previous lids were made of a cast iron construction secured to the pre-filter housing  62  with bolts. Removing the lid for maintenance was typically a time consuming task. The lid  78  and locking ring  90  in the present invention can be made from an injection molded process and are thus light in weight. The lid  78  further includes a clear top  79  that allows the user to view the contents of the pre-filter basket  74 . Furthermore, the lid  78  includes multiple ridges  80  equally spaced around the circumference of the lid  78  that are used in conjunction with the ridges  71  on the pre-filter housing  62  and with the locking ring  90  to secure the lid  78  to the pre-filter housing  62  as described below. The locking ring  90  further includes a reinforcing top  92  with multiple viewing openings  94  to allow the user to view the contents of the pre-filter basket  74 . The locking ring  90  further includes multiple knobs  96  and multiple slots  98 , located on the circumference of the locking ring  90 , that assist the user in securing the lid  78  to the pre-filter housing  62 . In securing the lid  78  to the pre-filter housing  62 , the user places the lid  78  on to the pre-filter housing  62  ensuring that the ridges  71  on the lid  78  line up with the ridges  80  on the pre-filter housing  62 . The user then places the locking ring  90  on to the lid  78  so both sets of ridges  71  and  80  extend through the slots  98 . The user then grasps the knobs  96  and partially rotates the locking ring  90  so that a portion of the ridge  71  on the pre-filter housing  62  engages the outer top portion  99  of the locking ring  90 , thereby securing the lid  78  to the pre-filter housing  62 . 
   Finally, the modular pre-pump filter  60  includes a wing type drain plug  100  located near the bottom of the pre-filter housing  62  that can be installed and removed without the use of any tools. 
   While specific embodiments of the invention have been described and illustrated, it is to be understood that these embodiments are provided by way of example only and that the invention is not to be construed as being limited thereto but only by proper scope of the following claims.