Patent Publication Number: US-9422661-B2

Title: Pump assembly for a washing machine appliance

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to pump assemblies for washing machine appliances and, in particular, to pump assemblies with a filter. 
     BACKGROUND OF THE INVENTION 
     Generally, washing machine appliances include a cabinet with a wash tub mounted therein. A wash basket is rotatably mounted within the wash tub and receives articles for washing. During operation of the appliance, washing fluid (e.g., water and/or detergent) is used to clean articles disposed within the wash basket. For example, after a user makes selections regarding wash and rinse cycles, the washing machine operates one or more valves to fill the wash tub with a certain amount of water. Additives such as detergent and fabric softeners may also be added manually or automatically to the water to form the washing fluid. 
     The wash tub may be drained and filled several times depending upon the wash and rinse cycles selected or programmed for the cleaning process. In addition, washing fluid may be circulated through the wash tub during wash or rinse cycles to assist in cleaning articles disposed in the wash basket. The washing machine can include a pump assembly for draining and/or recirculating fluid in the appliance. For example, the pump assembly can include a pump for draining the washing fluid from the wash tub, e.g., after completion of wash or rinse cycles. 
     The pump assembly is generally mounted below the wash tub within the appliance&#39;s cabinet. Presently, many components of the washing machine are mounted and/or stored below the wash tub, e.g., a bulk fluid dispenser. Accordingly, space within the cabinet below the wash tub is often at a premium. Thus, a pump assembly with features for conserving valuable space within the appliance&#39;s cabinet would be useful. 
     The pump assembly also generally includes a filter. The filter is mounted within the pump assembly and screens out e.g., buttons, lint, hair, dirt, and/or other particles that could potentially damage the pump assembly. However, a filter can require maintenance, e.g., cleaning out the filter. Such maintenance can be time consuming and inconvenient. Thus, a pump assembly with an improved filter and features for increasing the time period between cleanings of the filter would be appreciated. 
     During filter maintenance, a user must generally access the filter. In certain washing machine appliance, the pump assembly&#39;s filter can be difficult and/or inconvenient to access. Thus, during maintenance or service of pump assembly, valuable time and/or energy can be wasted accessing the pump assembly&#39;s filter. Accordingly, a pump assembly with features for facilitating access to a filter of the pump assembly would be useful. 
     In particular, certain filters are secured within a pump assembly with a cap having screw threads that require multiple complete rotations to secure the filter within the pump assembly. Thus, during maintenance, a user must complete multiple rotations of the cap to secure the filter. In addition, the cap can assist in compressing a seal on the filter to provide a water-tight barrier that prevents fluid from escaping the pump assembly. For example, certain filters include a face seal that must be compressed against a casing of the pump assembly to properly set. However, during maintenance, it can be difficult to ascertain if the cap has been sufficiently rotated to compress the seal against the casing. If the seal is not properly set, the pump assembly can leak during operation of the appliance. Thus, a pump assembly with features for conveniently securing a filter within the pump assembly without multiple complete rotations of a cap would be appreciated. Also, a pump assembly with filter having a seal that does not require multiple complete rotations of a cap to compress the seal would be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention. 
     In a first embodiment, a washing machine appliance is provided. The washing machine appliance includes a cabinet. A wash tub is received in the cabinet and configured for containing a fluid used in a washing process. A wash basket is mounted in the wash tub. The wash basket is configured for the receipt of articles during the washing process and for rotation about an axis. A drain is configured for directing fluid out of the cabinet. The washing machine appliance also includes a pump assembly. The pump assembly includes a casing that defines a chamber. The chamber extends longitudinally between a first end and a second end. The casing defines an inlet positioned adjacent the first end of the chamber. The inlet is configured for receipt of fluid from the wash tub. The casing also defines an opening positioned adjacent the second end of the chamber. The opening is configured for permitting selective access the chamber of the casing. A filter is received within the chamber of the casing. The filter extends longitudinally between a labyrinth filter portion and a mesh filter portion. A drain pump is in fluid communication with the chamber of the casing and the drain such that the drain pump selectively urges fluid disposed within the chamber to the drain. The drain pump positioned adjacent the labyrinth filter portion of the filter. A recirculation pump is in fluid communication with the chamber of the casing and the wash tub such that the recirculation pump selectively urges fluid disposed within the chamber to the wash tub. The recirculation pump is positioned adjacent the mesh filter portion of the filter. 
     In a second embodiment a pump assembly for a washing machine appliance is provided. The appliance has a cabinet that defines a compartment for receipt of articles for washing and a drain for directing fluid out of the appliance. The pump assembly includes a casing that defines a chamber. The chamber extends longitudinally between a first end and a second end. The casing defines an inlet positioned adjacent the first end of the chamber. The inlet is configured for receipt of fluid from the compartment of the cabinet. The casing also defines an opening positioned adjacent the second end of the chamber. The opening is configured for permitting selective access the chamber of the casing. A filter is received within the chamber of the casing. The filter extends longitudinally between a labyrinth filter portion and a mesh filter portion. A drain pump is in fluid communication with the chamber of the casing. The drain pump is configured for selectively urging fluid disposed within the chamber to the drain of the appliance. The drain pump receives fluid from the labyrinth filter portion of the filter. A recirculation pump is in fluid communication with the chamber of the casing. The recirculation pump is configured for selectively urging fluid disposed within the chamber to the compartment of the cabinet. The recirculation pump receives fluid from the mesh filter portion of the filter. 
     These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG. 1  provides a front view of an exemplary washing machine appliance according to an embodiment of the present subject matter; 
         FIG. 2  illustrates a cross-sectional view of the washing machine appliance of  FIG. 1  and, in particular, an exemplary pump assembly is shown. 
         FIG. 3  provides a perspective view of an exemplary pump assembly with an exemplary filter received within a casing of the pump assembly. 
         FIG. 4  illustrates a perspective view of an exemplary cap used to secure the filter within the casing shown in  FIG. 3 . 
         FIG. 5  illustrates a cross-sectional view of the cap shown in  FIG. 4 . 
         FIG. 6  provides a perspective view of the filter shown in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A pump assembly for a washing machine appliance is provided. The pump assembly includes a casing that receives a filter. The filter includes a labyrinth filter portion and a mesh filter portion. A drain pump is in fluid communication with the labyrinth filter portion, and a recirculation pump is in fluid communication with the mesh filter portion. Related washing machine appliances are also provided. Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. 
       FIG. 1  is a front view of an exemplary horizontal axis washing machine appliance  100  having a cabinet  102 .  FIG. 2  is a side cross-sectional view of washing machine appliance  100 . Cabinet  102  extends between a top  103  and a bottom  105 . Cabinet also includes a front panel  104 . A door  112  is mounted to front panel  104  and is rotatable about a hinge (not shown) between an open position (not shown) facilitating access to a wash basket  120  ( FIG. 2 ) located within cabinet  102 , and a closed position ( FIG. 1 ) prohibiting access to wash basket  120 . A user may pull on a handle  113  in order to adjust door  112  between the open position and the closed position. 
     A control panel  108  including a plurality of input selectors  110  is coupled to front panel  104 . Control panel  108  and input selectors  110  collectively form a user interface input for operator selection of machine cycles and features. For example, in one embodiment, a display  111  indicates selected features, a countdown timer, and/or other items of interest to machine users. 
     Referring now to  FIG. 2 , a wash tub  114  defines a wash compartment  119  configured for receipt of a washing fluid. Thus, wash tub  114  is configured for containing washing fluid. Washing fluid disposed in wash tub  114  may include, e.g., water, fabric softener, bleach, and/or detergent. Wash tub  114  includes a back wall  116  and a sidewall  118  and also extends between a top  115  and a bottom  117 . 
     Wash basket  120  is rotatably mounted within wash tub  114  in a spaced apart relationship from tub sidewall  118  and the tub back wall  116 . Basket  120  defines an opening  122  for receiving articles for washing. Basket  120  also defines a plurality of perforations  124  to facilitate fluid communication between an interior of basket  120  and wash tub  114 . A sump  107  is defined by wash tub  114  and is configured for receipt of washing fluid during operation of appliance  100 . For example, during operation of appliance  100 , washing fluid may be urged by gravity from basket  120  to sump  107  through plurality of perforations  124 . 
     A spout  130  is configured for directing a flow of fluid into wash tub  114 . Spout  130  may be in fluid communication with a water supply (not shown) in order to direct fluid (e.g., clean water) into wash tub  114 . Spout  130  may also be in fluid communication with the sump  107 . For example, a pump assembly  200  may direct washing fluid disposed in sump  107  to spout  130  in order to circulate washing fluid in wash tub  114 . In alternative exemplary embodiments, a spray nozzle (not shown) can be mounted adjacent door  112 , e.g., within a gasket (not shown) of door  112 . The spray nozzle may operate in a similar manner to spout  130  in order to direct fluid into wash tub  114 . Spout  130  and/or the spray nozzle may be mounted at any suitable location within washing machine appliance  100  in order to direct fluid into wash tub  114 . 
     Pump assembly  200  (shown schematically in  FIG. 2 ) is located beneath tub  114  for draining tub  114  of fluid. Pump assembly  200  is in fluid communication with sump  107  of wash tub  114  via a conduit  170 . Thus, conduit  170  directs fluid from wash tub  114  to pump assembly  200 . Pump assembly  200  is also in fluid communication with a drain  140  via piping  174 . Pump assembly  200  can urge fluid disposed in sump  107  to drain  140  during operation of appliance  100  in order to remove fluid from wash tub  114 . Fluid received by drain  140  from pump assembly  200  is directed out of appliance  100 , e.g., to a sewer or septic system. 
     In addition, pump assembly  200  is configured for recirculating washing fluid within wash tub  114 . Thus, pump assembly  200  is configured for urging fluid from sump  107 , e.g., to spout  130  or another portion of wash tub  114 . For example, pump assembly  200  may urge washing fluid in sump  107  to spout  130  and the spray nozzle (not shown) via hose  176  during operation of appliance  100  in order to assist in cleaning articles disposed in basket  120 . It should be understood that conduit  170 , piping  174 , and hose  176  may be constructed of any suitable mechanism for directing fluid, e.g., a pipe, duct, conduit, hose, or tube, and are not limited to any particular type of mechanism. 
     A motor  128  is in mechanical communication with basket  120  in order to selectively rotate basket  120 , e.g., during an agitation or a rinse cycle of washing machine appliance  100  as described below. Ribs  126  extend from basket  120  into wash compartment  119 . Ribs  126  assist agitation of articles disposed within wash compartment  119  during operation of washing machine appliance  100 . For example, ribs  126  may lift articles disposed in basket  120  during rotation of basket  120 . 
     A drawer  109  is slidably mounted within front panel  104 . Drawer  109  receives a fluid additive (e.g., detergent, fabric softener, bleach, or any other suitable liquid) and directs the fluid additive to wash compartment  119  during operation of appliance  100 . Additionally, a reservoir  160  is disposed within cabinet  102 . Reservoir  160  is also configured for receipt of fluid additive for use during operation of washing machine appliance  100  (shown in  FIG. 1 ). Reservoir  160  is sized such that a volume of fluid additive sufficient for a plurality or multitude of wash cycles of appliance  100  may fill reservoir  160 . Thus, for example, a user can fill reservoir  160  with fluid additive and operate appliance  100  for a plurality of wash cycles without refilling reservoir  160  with fluid additive. A reservoir pump  162  is configured for selective delivery of the fluid additive from reservoir  160  to wash tub  114 . 
     Operation of washing machine appliance  100  is controlled by a controller or processing device (not shown), that is operatively coupled to control panel  108  ( FIG. 1 ) for user manipulation to select washing machine cycles and features. In response to user manipulation of control panel  108 , the controller operates the various components of washing machine appliance  100  to execute selected machine cycles and features. 
     In an illustrative embodiment, laundry items are loaded into wash basket  120 , and washing operation is initiated through operator manipulation of input selectors  110 . Wash tub  114  is filled with water and detergent to form a wash fluid. One or more valves (not shown) can be controlled by washing machine appliance  100  to provide for filling wash tub  114  to the appropriate level for the amount of articles being washed. Once wash tub  114  is properly filled with fluid, the contents of wash basket  120  are agitated with ribs  126  for cleansing of laundry items in basket  120 . 
     After the agitation phase of the wash cycle is completed, wash tub  114  is drained. Laundry articles can then be rinsed by again adding fluid to wash tub  114 , depending on the particulars of the cleaning cycle selected by a user, ribs  126  may again provide agitation within wash compartment  119 . One or more spin cycles may also be used. In particular, a spin cycle may be applied after the wash cycle and/or after the rinse cycle in order to wring wash fluid from the articles being washed. During a spin cycle, basket  120  is rotated at relatively high speeds. 
     While described in the context of a specific embodiment of horizontal axis washing machine appliance  100 , using the teachings disclosed herein it will be understood that horizontal axis washing machine appliance  100  is provided by way of example only. Other washing machine appliances having different configurations, different appearances, and/or different features may also be utilized with the present subject matter as well, e.g., vertical axis washing machine appliances. In addition, the teachings disclosed herein may be used with other appliances as well, e.g., a dishwasher appliance. 
       FIG. 3  illustrates pump assembly  200 . Pump assembly  200  includes a housing or casing  210  that defines a chamber  211 . Casing  210  extends between a first end  216  and a second end  218 . An inlet  212  is defined by casing  210  adjacent first end  216  of casing  210 , and an opening  214  is defined by casing  210  adjacent second end  218  of casing  210 . Inlet  212  is configured for receiving fluid from wash tub  114  ( FIG. 2 ) and, thus, is in fluid communication with wash tub  114  via piping  170  ( FIG. 2 ). For example, during operation of appliance  100 , washing fluid from wash tub  114  may enter inlet  212  in order to fill chamber  211  of casing  210  with washing fluid. 
     Pump assembly  200  also includes a dual-stage filter  220  slidably received within chamber  211  of casing  210 . For example, filter  220  may slide into casing  210  through opening  214 . Thus, opening  214  permits access to chamber  211 , e.g., in order to remove and/or insert filter  220  into chamber  211 . Filter  220  includes two stages, a labyrinth filter portion  222  and a mesh filter portion  224 . Both labyrinth and mesh filter portions  222 ,  224  of filter  220  are configured for removing particles from a flow of fluid through chamber  211  of casing  210 . Labyrinth filter portion  222  is configured for removing relatively larger particles from fluid. For example, labyrinth filter portion  222  may be configured for removing foreign items such as buttons, pins, and/or coins. Conversely, mesh filter portion  224  is configured for removing relatively smaller particles from fluid. For example, mesh filter portion  224  may be configured for removing items such as hair, lint, and/or dirt. 
     A drain pump  240  is mounted to casing  210  adjacent labyrinth filter portion  222  of filter  220 . Drain pump  240  urges fluid in chamber  211  to drain  140  ( FIG. 2 ) through piping  174  ( FIG. 2 ). Thus, drain pump  240  is in fluid communication with chamber  211  and drain  140  and is configured for receipt of fluid from chamber  211 . For example, fluid from chamber  211  flows through a drain hole  229  defined by filter  220  into drain pump  240 . Fluid from chamber  211  passes through labyrinth portion  222  of filter  220  prior to entering drain pump  240 . Thus, large foreign objects (e.g., buttons, coins, and/or pins) disposed in the fluid are prevented from entering drain pump  240  and potentially damaging drain pump  240 , e.g., damaging an impeller (not shown) of drain pump  240 . However, labyrinth filter portion  222  permits smaller foreign objects (e.g., hair, lint, and/or dirt) to pass into drain pump  240  and exit appliance  100  via drain  140 . Thus, such smaller foreign objects are removed from appliance  100 . 
     A recirculation pump  230  is mounted to casing  210  adjacent mesh filter portion  224  of filter  220 . Recirculation pump  230  urges fluid in chamber  211  to spout  130  ( FIG. 2 ) through hose  176  ( FIG. 2 ). Thus, recirculation pump  230  is in fluid communication with chamber  211  and spout  130  and is configured for receipt of fluid from chamber  211 . For example, fluid from chamber  211  flows through a plurality of holes  228  defined by filter  220  into recirculation pump  230 . Fluid from chamber  211  passes through labyrinth filter portion  222  and mesh filter portion  224  of filter  220  prior to entering recirculation pump  230 . Thus, both large and small foreign objects disposed in the fluid are prevented from entering recirculation pump  230  and potentially damaging the recirculation pump  230 , e.g., damaging an impeller (not shown) of the recirculation pump  240 . Also, mesh filter portion  240  assists in preventing smaller foreign objects from clogging spout  130 . Similarly, in alternative exemplary embodiments, mesh filter portion  240  may prevent clogging of the spray nozzle (not shown) located at end of hose  176  (shown in  FIG. 2 ). 
     In  FIG. 3 , recirculation and drain pumps  230 ,  240  are positioned on casing  210  such that recirculation and drain pumps  230 ,  240  are substantially side-by-side. However, it should be understood that in alternative embodiments recirculation and drain pumps  230 ,  240  may be mounted to casing  210  in any suitable fashion, e.g., head-to-head or recirculation pump  230  may be mounted on top of drain pump  240  or vice versa. Alternatively, recirculation and drain pumps  230 ,  240  may be spaced apart from casing  210  and in fluid communication with chamber  211  using suitable conduits, pipes, hoses, ducts, etc. 
     A cap  250  is disposed adjacent opening  214  of casing  210 . Cap  250  is complementary in shape to opening  214  and is received within opening  214 . Cap  250  assists in securing filter  220  within chamber  211  of casing  210 . Cap  250  is discussed in greater detail below. 
       FIGS. 4 and 5  illustrate cap  250  securing filter  220  within chamber  211  of casing  210 . Cap  250  includes a circumferential surface  258  that is complementary in shape to opening  214  such that cap  250  may be received within opening  250  with circumferential surface  258  positioned adjacent casing  210 . Circumferential surface  258  defines slots  255  configured for receipt of tabs  260  ( FIG. 5 ) defined by casing  210 . Tabs  260  are positioned adjacent second end  218  of casing within opening  214 . Tabs  260  extend from casing  210  into opening  214 . Slots  255  receive tabs  260  and direct tabs to notches  256  defined by cap  250  on circumferential surface  258 . For example, a user may align a particular tab  260  with an entrance  259  of a particular slot  255  and guide the tab  260  into the slot  255 . The user may then rotate the cap  250  using a handle  276  of the cap  250 . As the cap  250  rotates, the tab  260  slides within the slot  255  until the tab  260  reaches the notch  256 . 
     Tabs  260  may be uniformly disposed on casing  210  about opening  214  such that cap  250  has a multiple insertion configurations. As an example, with three tabs  260  spaced one hundred and twenty degrees apart about opening  214 , a user may align any one of slots  255  with any one of tabs  260  to secure cap  250  to casing  210 . Conversely, tabs  260  may be non-uniformly disposed on casing  210  about opening  214  such that cap  250  has a single, unique insertion configuration. As an example, a first tab (not shown) may be spaced apart from a second tab (not shown) by about one hundred and ten degrees, the second tab may be spaced apart from a third tab (not shown) by about one hundred and twenty degrees, and the third tab may be spaced apart from the first tab by about one hundred and thirty degrees. In such a configuration, the user must align a particular one of the slots  255  with each of the first, second, and third tabs respectively to secure cap  250  to casing  210 . Thus, the cap  250  has only one, unique insertion configuration. Cap  250  can also include ID markings that communicate when the user has fully rotated cap  250 . 
     As shown in  FIG. 5 , cap  250  includes a spring  252  that extends between a first end  253  and a second end  254 . First end  253  of spring  252  is disposed adjacent cap  250 , and second end  254  of spring  252  is disposed adjacent filter  220 . Spring  252  urges filter  220  and cap  250  apart in order to assist in securing filter  220  within chamber  211  of casing  210 . For example, spring  252  urges the tab  260  into notch  256  in order to secure cap  250  in opening  214  of casing  210  by preventing cap  250  from rotating. With cap  250  mounted to casing  210 , spring  252  urges filter  220  into chamber  211  and, thus, prevents filter  220  from sliding out of chamber  211 . 
     However, cap  250  selectively secures filter  220  within chamber  211  of casing  210 . Thus, cap  250  also permits a user to selectively remove filter  220  from chamber  211 . For example, with cap securing filter  220  within chamber  211  as shown in  FIGS. 4 and 5 , a user may press cap  250  inward—i.e., towards casing  210 , to remove tab  260  from notch  256 . The user may then rotate cap  250  until tab  260  exits slot  255  at entrance  259 . The user can then remove cap  250  from opening  214  and slide filter  220  out of chamber  211 . Spring  252  can assist a user in removing cap  250  from casing  210 . For example, force applied by spring  252  combined with force applied by the user can urge cap  250  axially out of chamber  211  by pushing tabs  260  out of slots  255  at entrance  259 . 
     As discussed above, cap  250  selectively secures filter  220  within chamber  211 . To remove the tab  260  from slot  255 , the user may have to rotate the cap  250  about ninety degrees, sixty degrees, or any other suitable amount. However, cap  250  is configured such that cap  250  does not need to complete more than a single compete rotation (i.e., three hundred and sixty degrees) in order to remove cap  250  from opening  214 . In alternative embodiments, any suitable mechanism may be used to secure filter  220  within chamber  211 , e.g., a threaded cap or plug. 
     As may be seen in  FIG. 5 , second end  254  of spring  252  is mounted to a plug  270  of filter  220 . Plug  270  is complementary in shape to opening  214  and is positioned adjacent second end  218  of casing  210  at opening  214  in order to bung chamber  211 . Plug  270  has an outer circumferential surface  272  that is positioned adjacent casing  210 . A seal  274  is disposed on outer circumferential surface  272  to assist in sealing chamber  211  and preventing fluid from leaking out of chamber  211 , e.g., during operation of appliance  100 . Thus, seal  274  cooperates with casing  210  to inhibit fluid from exiting chamber  211  through opening  214 . Seal  274  compresses against casing  210  when filter  220  slides into chamber  211 . Thus, filter  220  and/or cap  250  need not be rotated to compress seal  274  against casing  210 . Seal  274  may include, e.g., an o-ring. In alternative embodiments, any suitable mechanism may be used to seal chamber  211 , e.g., a face seal. 
       FIG. 6  illustrates filter  220  disposed outside of chamber  211  ( FIG. 3 ). Filter  220  may be removed from chamber  211 , e.g., to clean filter  220  or service pump assembly  200 . Labyrinth filter portion  222  of filter  220  defines drain hole  229  for permitting fluid to flow through labyrinth filter portion  222  into drain pump  240  ( FIG. 3 ). Labyrinth filter portion  222  of filter  220  includes a plurality of projections  227  that extend from filter  220 . Plurality of projections  227  are configured for causing a flow of fluid through labyrinth filter portion  222  to change direction. Plurality of projections  227  are spaced and sized for impeding and/or catching relatively large foreign objects (e.g., buttons, coins, and/or pins). Thus, such large foreign objects may be prevented from entering, e.g., drain or recirculation pumps  230 ,  240  ( FIG. 3 ) by labyrinth filter portion  222 . 
     Mesh filter portion  224  of filter  220  includes a plurality of holes  228  that are defined by filter  220  and permit a flow of fluid through mesh filter portion  224  into recirculation pump  230  ( FIG. 3 ). Plurality of holes  228  are spaced and sized for impeding and/or catching relatively small foreign objects (e.g., hair, lint, and/or dirt). Thus, such small foreign objects may be prevented from entering, e.g., recirculation pumps  230  ( FIG. 3 ) by mesh filter portion  224 . 
     A partition  226  separates mesh filter portion  224  and labyrinth filter portion  222 . Thus, partition  226  is disposed between mesh filter portion  224  and labyrinth filter portion  222 . However, partition  226  does not prevent a flow of fluid between mesh filter portion  224  and labyrinth filter portion  222 . Thus, fluid can flow from labyrinth filter portion  222  into mesh filter portion  224 . Partition  226  is configured for prohibiting relatively large foreign objects from entering mesh filter portion  224  in order to prevent such objects from damaging components of pump assembly  200  (e.g., recirculation pump  230 ) (shown in  FIG. 3 ). 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.