Patent Publication Number: US-10779704-B2

Title: Dishwasher appliance having an integrated diverter

Description:
FIELD OF THE INVENTION 
     The present subject matter relates generally to dishwasher appliances and more particularly to diverters for dishwasher appliances. 
     BACKGROUND OF THE INVENTION 
     Dishwasher appliances generally include a tub and spray assemblies. The spray assemblies direct sprays of wash fluid onto articles within the tub during operation of the dishwasher appliance. The wash fluid sprayed from spray assemblies eventually flows to a sump typically positioned at a bottom portion of the tub. To supply wash fluid to the spray assemblies, dishwasher appliances generally include a pump, which may receive wash fluid from the sump to recirculate within the tub. Further, conventional dishwasher appliances typically use a diverter device to control the flow of fluid within the dishwasher appliance. Such diverter devices typically incorporate a diverter element within a diverter housing to selectively control which spray arm assemblies receives fluid. In this way, a single zone may be washed at a time, which may reduce the amount of water and energy needed to operate the dishwasher appliance. Such diverter devices are typically installed in or near the sump of the dishwasher appliance. 
     Separately forming the sump and a diverter housing poses certain challenges. For example, the joints between the sump and the tub and/or the sump and a diverter housing can leak, and fluid from such leaks can, for example, damage components of the dishwasher appliance and/or the area in which the dishwasher is installed, such as, e.g., kitchen cabinets that may surround the dishwasher and/or the floor beneath the dishwasher. Additional components to prevent leaks, such as, e.g., seals, gaskets, or the like, and/or manufacturing techniques such an overmolding process to depose a polymer or other suitable material onto, e.g., the diverter housing in the area where the housing is joined to the sump, can increase the time and expense of the dishwasher appliance and leaks can still occur in spite of such precautions. 
     Further, some dishwasher appliances are configured with a diverter device that selectively directs fluid to two zones and some dishwasher appliances are configured with a diverter device that selectively directs fluid to more than two zones. For two zone diverter devices, traditionally lower cost solutions have been used. As one example, a ball diverter system that includes a ball that is switchable between two outlet ports of the diverter depending on the selected zone may be employed. For diverter devices configured to selectively direct fluid to more than two zones, conventionally disc diverter systems or other systems are employed. Manufacture of these different diverter systems may pose certain challenges due to the geometries needed for such systems. For instance, the varying diverter system designs may require separate or different development processes, tooling, and/or manufacturing processes. 
     Accordingly, a dishwasher appliance having one or more features that address one or more of the noted challenges would be useful. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The present disclosure provides a dishwasher appliance that includes one or more features that provide for more efficient development of, tooling for, and manufacture of the dishwasher appliance. Further, the dishwasher appliance includes one or more features that reduce leakage between a sump and a diverter device of the dishwasher appliance, as well as part count. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention. 
     In a first exemplary embodiment, a dishwasher appliance is provided. The dishwasher appliance includes a tub defining a wash chamber. The dishwasher appliance also includes a plurality of spray arm assemblies for directing fluid into the wash chamber. Further, the dishwasher appliance includes a pump and a sump positioned at or proximate a bottom portion of the tub, the sump comprising a sump portion and a diverter bottom, the diverter bottom defining an inlet port in fluid communication with the pump and comprising an arcuate wall and a cylinder extending from the arcuate wall, the arcuate wall and the cylinder defining a chamber. In addition, the dishwasher appliance includes a diverter top removably mounted to the diverter bottom to form a diverter, the diverter top defining at least two outlets ports in fluid communication with the plurality of spray arm assemblies. Also, the dishwasher appliance includes a diverter element movable within the chamber, the diverter element configured to divert fluid from the inlet to the plurality of outlet ports. 
     In a second exemplary embodiment, a dishwasher appliance defining a vertical direction, a lateral direction, and a transverse direction is provided. The dishwasher appliance includes a tub defining a wash chamber and a plurality of spray arm assemblies for directing fluid into the wash chamber. The dishwasher appliance also includes a pump and a sump positioned at or proximate a bottom portion of the tub along the vertical direction, the sump comprising a sump portion and a diverter bottom integrally formed with the sump portion, the diverter bottom defining an inlet port in fluid communication with the pump, the diverter bottom comprising an arcuate wall extending between a top portion and a bottom portion along the vertical direction and a cylinder extending from the arcuate wall along the vertical direction, the arcuate wall and the cylinder defining a chamber. Further, the dishwasher appliance includes a diverter top removably mounted to the diverter bottom to form a diverter, the diverter top defining at least two outlets ports in fluid communication with the plurality of spray arm assemblies. Moreover, the dishwasher appliance includes a diverter element movable within the chamber, the diverter element configured to divert fluid from the inlet to the plurality of outlet ports. 
     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. 
         FIG. 1  provides a perspective view of an exemplary embodiment of a dishwasher appliance of the present disclosure with a door in a partially open position; 
         FIG. 2  provides a side, cross sectional view of the dishwasher appliance of  FIG. 1 ; 
         FIG. 3  provides a top perspective view of a diverter bottom according to an exemplary embodiment of the present disclosure; 
         FIG. 4  provides a perspective cross-sectional view of the diverter bottom of  FIG. 3  taken along line  4 - 4  of  FIG. 3 ; and 
         FIG. 5  provides a cross-sectional view of an exemplary diverter assembly of the dishwasher appliance of  FIGS. 1 and 2  depicting a disc diverter top mounted to a diverter bottom; 
         FIG. 6  provides a cross-sectional view of an exemplary diverter assembly of the dishwasher appliance of  FIGS. 1 and 2  depicting a ball diverter top mounted to the diverter bottom; and 
         FIG. 7  provides a perspective view of a diverter top mounted to diverter bottom according to an exemplary embodiment of the present disclosure. 
     
    
    
     Use of the same reference numerals in different figures denotes the same or similar features. 
     DETAILED DESCRIPTION 
     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. 
     As used herein, the term “article” may refer to, but need not be limited to dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during which a dishwashing appliance operates while containing the articles to be washed and uses a detergent and water to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “drain cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to discharge soiled water from the dishwashing appliance. The term “wash fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include other additives such as detergent or other treatments. Furthermore, as used herein, terms of approximation, such as “approximately,” “substantially,” or “about,” refer to being within a ten percent margin of error. 
       FIGS. 1 and 2  depict a dishwasher appliance  100  according to an exemplary embodiment of the present disclosure. Dishwasher appliance  100  defines a vertical direction V, a lateral direction L ( FIG. 1 ) and a transverse direction T. The vertical, lateral, and transverse directions V, L, and T are mutually perpendicular and form an orthogonal direction system. 
     Dishwasher  100  includes a housing or cabinet  102  having a tub  104  disposed therein that defines a wash chamber  106 . As shown in  FIG. 2 , tub  104  extends between a top  107  and a bottom  108  along the vertical direction V, between a pair of side walls  110  along the lateral direction L (only one shown in  FIG. 2 ), and between a front side and a rear side along the transverse direction T. Tub  104  includes a front opening  114  ( FIG. 1 ) and a door  116  hinged at its bottom for movement between a normally closed vertical position (shown in  FIG. 2 ), wherein the wash chamber  106  is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher  100 . Dishwasher  100  includes a door closure mechanism or assembly  118  ( FIG. 1 ) that is used to lock and unlock door  116  for accessing and sealing wash chamber  106 . 
     As further shown in  FIG. 2 , tub sidewalls  110  accommodate a plurality of rack assemblies. More specifically, guide rails  120  are mounted to sidewalls  110  for supporting a lower rack assembly  122  and an upper rack assembly  126 . Upper rack assembly  126  is positioned at a top portion of wash chamber  106  and lower rack assembly  122  is positioned at a bottom portion of wash chamber  106 . Each rack assembly  122 ,  126  is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber  106 , and a retracted position (shown in  FIGS. 1 and 2 ) in which the rack is located inside the wash chamber  106 . This is facilitated, for example, by rollers  128  mounted onto rack assemblies  122 ,  126 , respectively. Although guide rails  120  and rollers  128  are illustrated herein as facilitating movement of the respective rack assemblies  122 ,  126 , it should be appreciated that any suitable sliding mechanism or member may be used according to alternative embodiments. 
     Some or all of the rack assemblies  122 ,  126  are fabricated into lattice structures including a plurality of wires or elongated members  130  (for clarity of illustration, not all elongated members making up rack assemblies  122 ,  126  are shown in  FIG. 2 ). In this regard, rack assemblies  122 ,  126  are generally configured for supporting articles within wash chamber  106  while allowing a flow of wash fluid to reach and impinge on those articles, e.g., during a cleaning or rinsing cycle. According to other exemplary embodiments, a silverware basket (not shown) may be removably attached to a rack assembly, e.g., lower rack assembly  122 , for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by rack  122 . 
     Dishwasher  100  further includes a plurality of spray assemblies for urging a flow of water or wash fluid onto the articles placed within wash chamber  106 . More specifically, as illustrated in  FIG. 2 , dishwasher  100  includes a lower spray arm assembly  134  disposed in a lower region  136  of wash chamber  106  and above a sump  138  so as to rotate in relatively close proximity to lower rack assembly  122 . Similarly, a mid-level spray arm assembly  140  is located in an upper region of wash chamber  106  and is disposed below upper rack assembly  126  along the vertical direction V. In this regard, mid-level spray arm assembly  140  is generally configured for urging a flow of wash fluid up through upper rack assembly  126 . Additionally, an upper spray assembly  142  may be located above upper rack assembly  126  along the vertical direction V. In this manner, upper spray assembly  142  may be configured for urging and/or cascading a flow of wash fluid downward over rack assemblies  122 ,  126 . 
     The various spray assemblies described herein may be part of a fluid circulation assembly  150  for circulating water and wash fluid in tub  104 . In addition to the spray assemblies, fluid circulation assembly  150  includes a pump  152  for circulating water and wash fluid (e.g., detergent, water, and/or rinse aid) to the spray assemblies such that wash fluid may be dispensed in tub  104 . Pump  152  is located within a machinery compartment located below or proximate sump  138  of tub  104 . For this exemplary embodiment, pump  152  receives fluid from sump  138  through a pump inlet  153  and pumps the wash fluid through a pump outlet  155  to an inlet port  238  ( FIGS. 3 and 4 ) of a diverter  200 . Diverter  200  selectively distributes the wash fluid to the spray arm assemblies  134 ,  140 ,  142  and/or other spray manifolds or devices such that wash fluid is sprayed into tub  104  into a desired zone. Fluid circulation assembly  150  may include various fluid conduits or circulation piping for directing water and/or wash fluid from diverter  200  to the various spray assemblies  134 ,  140 , and  142 . For example, for the embodiment depicted in  FIG. 2 , supply conduit  154  extends from diverter  200  to mid-level spray arm assembly  140  and upper spray assembly  142  and supply conduit  156  extends from diverter  200  to lower spray arm assembly  134  to supply wash fluid thereto. However, it should be appreciated that according to alternative embodiments, any other suitable plumbing configuration may be used to supply wash fluid throughout the various spray manifolds and assemblies described herein. For example, according to another exemplary embodiment, supply conduit  154  could be used to provide wash fluid to mid-level spray arm assembly  140  and a dedicated secondary supply conduit (not shown) could be utilized to provide wash fluid to upper spray assembly  142 . Other plumbing configurations may be used for providing wash fluid to the various spray devices and manifolds at any location within dishwasher appliance  100 . 
     Each spray assembly  134 ,  140  includes an arrangement of discharge ports or orifices for directing washing liquid received from diverter  200  onto dishes or other articles located in upper and lower rack assemblies  120 . The arrangement of the discharge ports in spray-arm assemblies  134 ,  140  provides a rotational force by virtue of washing fluid flowing through the discharge ports. The resultant rotation of spray-arm assemblies  134 ,  140  and the operation of spray assembly  142  using fluid from diverter  200  provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well. 
     Dishwasher  100  is equipped with a controller  160  to regulate operation of dishwasher  100 , e.g., to control which zones within wash chamber  106  are to receive wash fluid. Controller  160  may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In some embodiments, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller  160  may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, bistable gates, AND gates, and the like) to perform control functionality instead of relying upon software. 
     Controller  160  may be positioned in a variety of locations throughout dishwasher  100 . In the illustrated embodiment, controller  160  may be located within a control panel area  162  of door  116  as shown in  FIGS. 1 and 2 . In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher  100  along wiring harnesses that may be routed through the bottom of door  116 . Typically, the controller  160  includes a user interface panel/controls  164  through which a user may select various operational features and modes and monitor progress of the dishwasher  100 . In one embodiment, the user interface  164  may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface  164  may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface  164  may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface  164  may be in communication with the controller  160  via one or more signal lines or shared communication busses. 
     It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher  100 . The exemplary embodiment depicted in  FIGS. 1 and 2  is for illustrative purposes only. For example, different locations may be provided for user interface  164 , different configurations may be provided for rack assemblies  122 ,  126 , different spray arm assemblies  134 ,  140 ,  142  may be used, and other differences may be applied while remaining within the scope of the present subject disclosure. 
       FIGS. 3 and 4  provide various views of sump  138  having a diverter bottom  202  integrated with a sump portion  139  of sump  138  according to various exemplary embodiments of the present disclosure. In particular,  FIG. 3  provides a top perspective view of diverter bottom  202  integrally formed with sump  138 .  FIG. 4  provides a perspective cross-sectional view of diverter bottom  202  integrally formed with sump  138  taken along line  4 - 4  of  FIG. 3 . 
     Notably, for this embodiment, diverter bottom  202  is integrally formed with sump portion  139  of sump  138 , as noted above and as will be explained in further detail herein. As diverter bottom  202  is integrally formed with sump  138 , e.g., with a sump portion  139  of sump  138 , leaks between sump  138  and diverter bottom are eliminated or reduced, assembly time is reduced as there is no longer a need to mount diverter bottom  202  to sump  138 , and further, the part count of sump  138  and diverter bottom  202  may be reduced as mechanical fasteners are not needed to mount diverter bottom  202  to sump  138 . Moreover, for this exemplary embodiment, diverter bottom  202  is configured such that it may receive varying diverter tops to form diverter  200 . For instance, for this exemplary embodiment, diverter bottom  202  is configured to receive a disc diverter top coupled with a disc diverting element ( FIG. 5 ) and may also receive a ball diverter top with a ball as the diverting element ( FIG. 6 ). Advantageously, as diverter bottom  202  is configured for use with multiple diverter tops, e.g., disc diverter top  204  of  FIG. 5  and ball diverter top  206  of  FIG. 6 , development of, tooling for, and manufacture of unitary sump  138  and integrated diverter bottom  202  of diverter  200  may be made more efficient and less costly. Sump  138  with integrated diverter bottom  202  will now be described in greater detail. 
     For reference purposes, diverter bottom  202  defines an axial direction A, a radial direction R extending outward from the actual direction A, and a circumferential direction C (e.g., extending three hundred sixty degrees) (360°) about the axial direction A). For this embodiment, the axial direction A extends along the vertical direction V ( FIGS. 1 and 2 ). In addition, diverter bottom  202  defines an axial centerline AC as shown in  FIG. 4 . 
     As shown in  FIGS. 3 and 4 , diverter bottom  202  defines chamber  208 , as noted above. Generally, for this exemplary embodiment, chamber  208  has a bowl-like shape and is sized to receive at least a portion of a diverter top therein. For instance, in  FIG. 5  a portion of disc diverter top  204  is received or disposed within chamber  208  of diverter bottom  202 . In  FIG. 6 , ball diverter top  206  is received or disposed within chamber  208  of diverter bottom  202 . 
     More particularly, with reference to  FIGS. 3 and 4 , chamber  208  is defined by a number of walls and other internal features of diverter bottom  202 . As shown, chamber  208  extends between a top region  210  and a bottom region  212  along the axial direction A ( FIG. 4 ), which is the vertical direction V in this embodiment, and between a first side  214  and a second side  216  along a first radial direction R 1  and between a third side  218  and a fourth side  220  along a second radial direction R 2  ( FIG. 3 ), which is a direction orthogonal to the first radial direction R 1 . Top region  210  of chamber  208  is defined by a circumferential wall  222  that extends about the circumferential direction C and extends above and below sump portion  139  of sump  138  along the axial direction A, as shown particularly in  FIG. 4 . Circumferential wall  222  defines top region  210  of chamber  208 . Circumferential wall  222  is positioned adjacent a circumferential flange  224  that is disposed radially outward of and about circumferential wall  222  along the circumferential direction C. Circumferential flange  224  connects diverter bottom  202  with sump portion  139  and defines a perimeter of diverter bottom  202 . 
     A chamfered ridge  226  extends inward from circumferential wall  222  along the radial direction R with respect to the axial centerline AC. As shown, chamfered ridge  226  extends along the circumferential direction C along at least a portion of circumferential wall  222 . For this exemplary embodiment, chamfered ridge  226  does not extend from circumferential wall  222  at or proximate an inlet region  228  of chamber  208 . In alternative exemplary embodiments, chamfered ridge  226  may extend about the entire circumferential wall  222 . 
     As further shown in  FIGS. 3 and 4 , various surfaces of a recessed member  230  also defined chamber  208 . As shown, recessed member  230  includes a recessed wall  232  that extends from chamfered ridge  226  along at least a portion of chamfered ridge  226 . Recessed wall  232  extends in a plane orthogonal to the axial direction A. A first sidewall  234  of recessed member  230  shares an edge with recessed wall  232  and extends generally between the first side  214  and second side  216  along the first radial direction R 1  and in a plane along the axial direction A. Further, recessed member  230  includes a second sidewall  236  that shares an axial extending edge with first sidewall  234  and a radial extending edge with recessed wall  232 . As depicted, second sidewall  236  defines an inlet port  238 . Inlet port  238  is configured to receive a flow of wash fluid from pump  152  ( FIG. 2 ) so that diverter  200  may selectively allow a flow of fluid to one or more spray assemblies. Accordingly, inlet port  238  is in fluid communication with pump  152 . 
     In addition, in this exemplary embodiment, a rib  240  extends from second sidewall  236 . Rib  240  extends from second sidewall  236  and is positioned such that inlet port  238  is partially blocked or obstructed by rib  240 . In this way, when diverter bottom  202  is paired with ball diverter top  206  ( FIG. 6 ), as will be explained further below, a ball that functions as a diverting device is prevented from flowing into inlet port  238 . Rib  240  extends from second sidewall  236  and terminates at an arcuate wall  242  of diverter bottom  202 . 
     Generally, arcuate wall  242  defines a hemispherical volume of chamber  208 , save for recessed member  230  and other features of diverter bottom  202  (e.g., rib  240 ) disposed within the hemispherical volume of chamber  208 . As shown, arcuate wall  242  extends between a top portion  246  and a bottom portion  248  along the axial direction A (or vertical direction V). At top portion  246 , arcuate wall  242  extends from chamfered ridge  226  and curves inward along the radial direction R and downward along the axial direction A to bottom portion  248 . A cylinder  250  extends from arcuate wall  242  at or proximate bottom portion  248  of arcuate wall  242 . Cylinder  250  defines a cylindrically-shaped well  252  of chamber  208  that is a volume contiguous or continuous with the hemispherical volume. Cylinder  250  defines an opening  254  in arcuate wall  242  at bottom portion  248 . More particularly, cylinder  250  defines opening  254  in arcuate wall  242  at a bottom dead center BDC position of arcuate wall  242  ( FIG. 4 ). Opening  254  in arcuate wall  242  is sized such that a ball functioning as a diverter device ( FIG. 6 ) is prevented from traveling or falling into well  252  of cylinder  250 . 
     For this embodiment, describing arcuate wall  242  along the first radial direction R 1  and beginning at first side  214  of chamber  208 , as shown, arcuate wall  242  extends from chamfered ridge  226  at first side  214  of chamber  208  and curves inward along the radial direction R and downward along the axial direction A to bottom portion  248  of arcuate wall  242 , as noted above. After reaching bottom dead center BDC, arcuate wall  242  curves outward from the axial centerline AC along the radial direction R and upward along the axial direction A (or vertical direction V in this embodiment). At least a portion of arcuate wall  242  terminates at an inlet ridge  256 . A gap G is defined between inlet ridge  256  and rib  240 , as shown particularly in  FIG. 4 . Rib  240  comprises a rib path portion  258  that has a height that is complementary to the curvature of arcuate wall  242 . That is, if arcuate wall  242  did not terminate at inlet ridge  256 , rib path portion  258  has the height that arcuate wall  242  would have had along the axial direction A (or vertical direction V). 
     In this way, when the diverter top mounted to diverter bottom  220  is ball diverter top  206  and the diverter device is a ball (e.g.,  FIG. 6 ), arcuate wall  242  and rib  240 , and more particularly rib path member  258 , along with ball diverter top  206  define a ball path BP along which the ball is movable between a first position and a second position, or stated alternatively, the ball is movable to obstruct a first outlet port or a second outlet port defined by ball diverter top  206 . 
     In alternative exemplary embodiments, diverter bottom  202  may not include rib  240 . For instance, diverter bottom  202  is shown in  FIGS. 5 and 6  without a rib structure. In such embodiments, arcuate wall  242  has a semicircular cross section as shown in  FIGS. 5 and 6  that extends between first side  214  and second side  216  along the first radial direction R. Accordingly, in such embodiment, when the diverter top mounted to diverter bottom  220  is ball diverter top  206  and the diverter device is a ball (e.g.,  FIG. 6 ), arcuate wall  242  and ball diverter top  206  define ball path BP along which the ball is movable between a first position and a second position. 
     Further, for this exemplary embodiment, as noted above, sump portion  139  and diverter bottom  202  are integrally formed from a continuous piece of material such that sump portion  139  and diverter bottom  202  have a unitary construction and form unitary sump  138 . That is, sump portion  139  and diverter bottom  202  are made together as a single unit or piece during manufacturing, i.e., from a continuous piece of material, to form unitary sump  138 . A plastic, polymer, metal, or other material may be an appropriate material for constructing unitary sump  138 . In some embodiments, unitary sump  138  may be formed from a combination of materials that are integrally formed as a continuous piece. That is, although one portion of sump  138  may be formed of a different material than another portion, the portions are integrally formed such that the portions are formed of a single, continuous piece, i.e., the different materials are integral. 
     The term “unitary” as used herein denotes that the associated component, such as sump  138  described herein, is made as a single piece during manufacturing, i.e., from a continuous piece of material. Thus, a unitary component has a monolithic construction and is different from a component that has been made from a plurality of component pieces that have been joined together to form a single component. More specifically, in the exemplary embodiment of  FIGS. 3 and 4 , sump portion  139  and diverter bottom  202  are constructed as a single unit or piece to form unitary sump  138 . 
     A plastic, polymer, metal, or other material may be an appropriate material for constructing the unitary sump  138 . In some embodiments, a combination of materials may be integrally formed as a continuous piece to form the unitary sump  138 . That is, although one portion of sump  138  may be formed of a different material than another portion, the portions are integrally formed such that the portions are formed of a single, continuous piece, i.e., the different materials are integral. For example, the continuous piece of material may include a first material and a second material. In the exemplary embodiment of  FIG. 3 , sump portion  139  may be formed of the second material and diverter bottom  202  may be formed of the first material. The first and second materials may form a continuous piece of material, e.g., by fusing together the first and second materials where they meet or by successively printing one layer of sump  138  on top of another, as further described below. 
     In other embodiments, diverter bottom  202  may comprise a pre-fabricated structure and sump portion  139  is formed around diverter bottom  202  to produce unitary sump  138 . For example, sump  138  may be formed using an additive process as described below and pre-fabricated diverter bottom  202  may be inserted within sump portion  139  during the additive process to form unitary sump  138  having diverter bottom  202 . 
       FIGS. 5 and 6  provide views of varying diverter tops removably mounted to diverter bottom  202  according to exemplary embodiments of the present disclosure. More particularly,  FIG. 5  provides disc diverter top  204  removably mounted to diverter bottom  202  and  FIG. 6  provides ball diverter top  206  removably mounted to diverter bottom  202 . Notably, diverter bottom  202  has the same geometry in  FIGS. 5 and 6  while the diverter tops removably mounted thereto have different geometries. 
     As shown in  FIG. 5 , disc diverter top  204  defines a plurality of outlet ports; however, only a first outlet port  260  and a second outlet port  262  are shown in the cross-section view of the exemplary embodiment of  FIG. 5 . In alternative embodiments, disc diverter top  204  may define two, three, four, or more outlet ports depending upon, e.g., the number of switchable ports desired for selectively placing pump  152  ( FIG. 2 ) in fluid communication with different fluid-using elements of dishwasher  100  ( FIG. 2 ). 
     For the depicted embodiment of  FIG. 5 , diverter  200  includes a rotatable diverter element  264  that is operatively coupled with disc diverter top  204 . As shown, diverter element  264  has an aperture  266  that can be selectively switched between the plurality of outlet ports, including first and second outlet ports  260  and  262 . For example, the outlet ports may be spaced apart along a circumferential direction C, and in an exemplary embodiment having four outlet ports, the outlet ports may be spaced apart along the circumferential direction C at angles of ninety degrees (90°). Thus, the rotation of diverter element  264  by ninety degrees (90°) necessarily rotates aperture  266  so as to selectively provide fluid flow from one outlet port to the next outlet port along the direction of rotation. 
     In the exemplary embodiment of  FIG. 5 , diverter element  264  is a disc  268  that can be rotated about the axial centerline AC to selectively switch aperture  266  between the plurality of outlet ports to place an outlet port in fluid communication with chamber  208  of disc diverter top  204 . Thus, through the rotation of diverter element  264 , diverter  200  can be used to selectively provide fluid flow from pump  152  through chamber  208  to any one of the outlet ports. By way of example, first outlet port  260  can be fluidly connected with upper spray assembly  142 , second outlet port  262  can be fluidly connected with mid-level spray-arm assembly  140 , and third and fourth outlet ports might be fluidly connected with lower spray-arm assembly  134  (see  FIG. 2 ). As such, the rotation of disc  268  can be used to selectively place pump  152  in fluid communication with any one of the spray assemblies  142 ,  140 , or  134  by way of the plurality of outlet ports. Other connection configurations may be used as well. 
     For this exemplary embodiment, a cylindrically-shaped shaft  270  extends from disc  268 . More particularly, shaft  270  extends downward from disc  268  along the axial direction A. Shaft  270  extends at least partially into cylindrically-shaped well  252  defined by cylinder  250  that forms part of diverter bottom  202 . As shown, well  252  defined by cylinder  250  is part of chamber  208  and is contiguous with the hemispherical volume of chamber  208  generally defined by arcuate wall  242 , circumferential wall  222 , chamfered ridge  226 , etc. Shaft  270  is movable within well  252  of cylinder  250  along the axial direction A between a first position ( FIG. 5 ) and a second position (not shown), denoted by arrow M in  FIG. 5 . Moreover, shaft  270  is rotatable about the axial centerline AC relative to diverter bottom  202 , e.g., as disc  268  is rotated about to selectively direct fluid into the appropriate outlet port. 
     In addition, for this embodiment, diverter  200  is a passive diverter device. That is, diverter device  200  does not include a driving element, e.g., a motor, to actively switch diverter element  264  between various positions to selectively control the flow of fluid to particular spray assemblies. Rather, diverter  200  of  FIG. 3  relies on passive forces, such as e.g., the pressure of the fluid within diverter  200  or more broadly the fluid system as is known in the art, to drive internal features within disc  268  and shaft  270  such that rotation of diverter element  264  is accomplished. As one example, when passive forces are not acting on the internal features within disc  268  and shaft  270 , the disc  268  and shaft  270  extending therefrom are moved downward along the axial direction A via gravity, e.g., within well  252  of cylinder  250 . When passive forces are applied to the internal features within disc  268  and shaft  270  bias disc  268  in the circumferential direction C while passive forces push upward along the axial direction A. Consequently, rotation of disc  268  and shaft  270  results. In this way, aperture  266  defined by disc  268  is moved, e.g., along the circumferential direction C, such that fluid communication between pump  152  and another spray assembly is achieved. In alternative exemplary embodiments, a motor or other driving element may be mechanically coupled with shaft  270 . In such alternative embodiments, the motor may drive shaft  270  about such that disc  268  rotates and aperture  266  is positioned in the desired position such that fluid may flow to the desired wash zone within tub  104 . 
     As shown in  FIG. 6 , ball diverter top  206  is mounted to diverter bottom  202 , which has the same geometry of the diverter bottom depicted in  FIG. 5 . Ball diverter top  206  defines a plurality of outlet ports. For this exemplary embodiment, ball diverter top  206  defines two outlet ports, including first outlet port  280  and second outlet port  282 . In some embodiments, ball diverter top  206  may define more than two outlet ports. Outlet ports  280 ,  282  are in fluid communication with one or more of the spray arm assemblies  134 ,  140 ,  142  ( FIG. 2 ). 
     For this exemplary embodiment, diverter element  264  is a ball  284  that is movable between a first position and a second position along U-shaped ball path BP. In the first position P 1  (shown in phantom in  FIG. 6 ), ball  284  obstructs first outlet port  280  from receiving a flow of wash fluid and thus diverts a fluid flow to second outlet port  282 . When ball  284  is in the second position P 2  (shown in phantom in  FIG. 6 ), ball  284  obstructs second outlet port  282  from receiving a flow of wash fluid and thus diverts a fluid flow to first outlet port  280 . Ball  284  may be moved between the first and second positions P 1 , P 2  due to fluid pressure exerted on diverter ball  284  during operation of dishwasher appliance  100  ( FIGS. 1 and 2 ). For example, prior to the operation of dishwasher  100 , ball  284  may be positioned at an intermediate location along ball path BP between first and second outlet ports  280 ,  282 , such as at the position of ball  284  shown in  FIG. 6 . Thereafter, when pump  152  begins to deliver fluid to diverter  200 , the pressure of the fluid flowing into diverter bottom  202  via diverter inlet port  238  ( FIGS. 3 and 4 ) may force ball  284  upwards into its first position P 1  such that it is sealed against first outlet port  280 . As such, all of the fluid flowing into diverter  200  may be initially diverted to second outlet port  282  for subsequent discharge to one of the spray arm assemblies. Thereafter, when it is desired to divert the fluid from pump  152  ( FIG. 2 ) to first outlet port  280 , pump  152  may be temporarily cut off such that the pressure build-up of the fluid contained within fluid circulation assembly  150  ( FIG. 2 ) forces ball  284  into its second position P 2  such that it is sealed against second outlet port  282 . Pump  152  may then be turned on such that the pressure of the fluid flowing into diverter bottom  202  via diverter inlet port  238  maintains ball  284  sealed against second outlet port  282 , thereby allowing the fluid flowing into diverter  200  to be diverted to first outlet port  280  for subsequent discharge from other spray arm assemblies or manifolds. 
     As further shown in  FIG. 6 , at least a portion of ball diverter top  206  is received or disposed within chamber  208  of diverter bottom  202 , and when ball diverter top  206  is mounted with diverter bottom  202 , ball path BP is defined between ball diverter top  206  and arcuate wall  242  of diverter bottom  202  along the axial direction A (or vertical direction V in this embodiment). More particularly, ball diverter top  206  includes a top wall  286  that is shaped complementary to arcuate wall  242  of diverter bottom  202 . In this way, when ball diverter top  206  is mounted with diverter bottom  202 , U-shaped ball path BP is defined between arcuate wall  242  of diverter bottom  202  and top wall  286  of ball diverter top  206 . 
     In addition, to constrain the movement of ball  284  within ball path BP, ball diverter top  206  includes a sidewall  288  (shown transparent in  FIG. 6 ) that extends in a plane along the axial direction A (or vertical direction V). Sidewall  288  is spaced from first sidewall  234  of recessed member  230  ( FIGS. 3 and 4 ) and extends parallel or substantially parallel to first sidewall  234  of diverter bottom  202 . Sidewall  288  is spaced from first sidewall  234  so as to accommodate ball  284  within ball path BP. In this way, first sidewall  234  of recessed member  230  of diverter bottom  202  and sidewall  288  of ball diverter top  206  constrain ball  284  along the ball path BP, e.g., along the second radial direction R 2  ( FIG. 3 ). 
       FIG. 7  provides a perspective view of disc diverter top  204  mounted to diverter bottom  202  of sump  138 . As shown, disc diverter top  204  may be mounted to diverter bottom  202  by twisting disc diverter top  204  about the axial direction A (or vertical direction V in this embodiment) such that locking features of diverter bottom  202  interlock with features of disc diverter top  204 . 
     For instance, as shown particularly in  FIG. 3 , a first guide member  290  and a second guide member  292  project from circumferential flange  224  upward along the axial direction A and each extend along the circumferential direction C. Further, a lock tab  294  also projects from circumferential flange  224  upward along the axial direction A and extends along the circumferential direction C. As shown in  FIG. 3 , lock tab  294  includes an inner surface  296  that is wedged or angled with respect to the circumferential direction C. 
     With reference to  FIG. 7 , to install disc diverter top  204  with diverter bottom  202 , disc diverter top  204  is positioned such that it is aligned with diverter bottom  202 . Disc diverter top  204  is then lowered along the axial direction A such that disc diverter top  204  is in mating communication with diverter bottom  202 . Notably, when disc diverter top  204  is positioned in mating communication with diverter bottom  202 , first guide member  290  is received within a first groove  298  defined by circumferential wall  222  of diverter top  204  and second guide member  292  is received within a second groove (not shown) defined by circumferential wall  222 . Thereafter, disc diverter top  204  is twisted about the axial direction A, and as this occurs, a lock strip  299  of disc diverter top  204  engages lock tab  294 . When lock strip  299  of disc diverter top  204  engages lock tab  294  of diverter bottom  202 , lock strip  299  is wedged against inner surface  296  of lock tab  294 . This locks diverter top  204  in place and prevents further rotation of disc diverter top  204  about the axial direction A. In this way, disc diverter top  204  is secured to diverter bottom  202 . To uninstall disc diverter top  204  from diverter bottom  202 , a twisting force is applied to disc diverter top  204  such that lock strip  299  of diverter top  204  disengages from inner surface  296  of lock tab  294 . Ball diverter top  206  ( FIG. 6 ) may be installed or removed from diverter bottom  202  to form diverter  200  in the same or similar manner as described above. As the diverter tops may be mounted to or removed from diverter bottom  202 , the diverter tops are removably mounted from diverter bottom  202 . 
     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 language of the claims.