The present disclosure relates generally to dishwasher appliances, and more particularly to improved drain systems within dishwasher appliances.
Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Wash fluid (e.g., various combinations of water and detergent along with optional additives) may be introduced into the tub where it collects in a sump space at the bottom of the wash chamber. During wash and rinse cycles, a pump may be used to circulate wash fluid to spray assemblies within the wash chamber that can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. During a drain cycle, a drain pump may periodically discharge soiled wash fluid that collects in the sump space and the process may be repeated.
As part of a normal drain cycle, the dishwasher uses the drain pump to discharge soiled wash fluid through a drain hose to an external drain. Notably, the external drain is typically located above the drain pump. To prevent the soiled wash fluid from flowing back into the sump of the dishwasher, conventional drain system designs position a check valve on the drain hose, e.g., downstream of the drain pump, to prevent wash fluid in the drain hose from reentering the drain pump or sump.
Notably, such a configuration results in several disadvantages. For example, the volume of soiled wash fluid that remains in the drain pump upstream of the check valve could reenter the sump and be recirculated onto the dishes during a subsequent wash cycle. In addition, to resolve drain clog issues, the check valve would need to be accessed by removing the dishwasher from the cabinet. Notably, such a procedure is time consuming and costly. In addition, because the conventional check valve prevents wash fluid from remaining in a drain volute of the drain pump, the pump may become “air locked” and require priming before effective pumping may be achieved during the next drain cycle. This priming procedure typically involves pulsing the drain pump on and off to remove air from the drain volute, which degrades sound quality and the user experience in general.
Accordingly, a dishwasher appliance that utilizes an improved check valve assembly would be useful. More specifically, a check valve assembly that prevents the backflow of soiled wash fluid, simplifies the process for removing clogs, and improves the general operation of the dishwasher appliance would be particularly beneficial.
The present subject matter provides a dishwasher appliance including a drain basin defined at a bottom of a sump of the dishwasher. The drain basin defines a discharge port and a drain pump is in fluid communication with the discharge port for selectively urging a flow of wash fluid through the discharge port to an external drain during a drain cycle. A check valve assembly includes a check valve removably positioned over the discharge port between the drain pump and the drain basin and a positioning arm attached to the check valve for positioning and locking the check valve in place. Additional aspects and advantages of the invention will be set forth in part in the following description, may be apparent from the description, or may be learned through practice of the invention.
In accordance with one exemplary embodiment of the present disclosure, a dishwasher appliance defining a vertical direction is provided. The dishwasher appliance includes a wash tub that defines a wash chamber and a sump for collecting wash fluid. A drain basin is defined at a bottom of the sump, the drain basin defining a discharge port, and a drain pump is in fluid communication with the discharge port for selectively urging a flow of wash fluid through the discharge port to an external drain during a drain cycle. A check valve assembly includes a check valve removably positioned over the discharge port between the drain pump and the drain basin and a positioning arm attached to the check valve for positioning and locking the check valve in place.
In accordance with another exemplary embodiment of the present disclosure, a drain pump assembly for a dishwasher appliance is provided. The drain pump assembly includes a drain basin defined at a bottom of a sump of the dishwasher appliance, the drain basin defining a discharge port, and a drain pump in fluid communication with the discharge port for selectively urging a flow of wash fluid through the discharge port. A check valve is removably positioned over the discharge port between the drain pump and the drain basin and a positioning arm is attached to the check valve for positioning and locking the check valve in place.
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.
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.
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
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, preferably with agitation, 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.
The tub 104 includes a front opening 114 and a door 116 hinged at its bottom for movement between a normally closed vertical position (shown in
As best illustrated in
Some or all of the rack assemblies 122, 124, 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, 124, 126 are shown in
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
The various spray assemblies and manifolds described herein may be part of a fluid distribution system or fluid circulation assembly 150 for circulating water and wash fluid in the tub 104. More specifically, fluid circulation assembly 150 includes a pump 152 for circulating water and wash fluid (e.g., detergent, water, and/or rinse aid) in the tub 104. Pump 152 may be located within sump 138 or within a machinery compartment located below sump 138 of tub 104, as generally recognized in the art. Fluid circulation assembly 150 may include one or more fluid conduits or circulation piping for directing water and/or wash fluid from pump 152 to the various spray assemblies and manifolds, e.g., during wash and/or rinse cycles. For example, as illustrated in
As illustrated, primary supply conduit 154 is used to supply wash fluid to one or more spray assemblies, e.g., to mid-level spray arm assembly 140 and upper spray assembly 142. 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, primary 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 arm assembly 134, 140, 142, integral spray manifold 144, or other spray device may include an arrangement of discharge ports or orifices for directing wash fluid received from pump 152 onto dishes or other articles located in wash chamber 106. The arrangement of the discharge ports, also referred to as jets, apertures, or orifices, may provide a rotational force by virtue of wash fluid flowing through the discharge ports. Alternatively, spray arm assemblies 134, 140, 142 may be motor-driven, or may operate using any other suitable drive mechanism. Spray manifolds and assemblies may also be stationary. The resultant movement of the spray arm assemblies 134, 140, 142 and the spray from fixed manifolds provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well. For example, dishwasher 100 may have additional spray assemblies for cleaning silverware, for scouring casserole dishes, for spraying pots and pans, for cleaning bottles, etc. One skilled in the art will appreciate that the embodiments discussed herein are used for the purpose of explanation only, and are not limitations of the present subject matter.
In operation, pump 152 draws wash fluid in from sump 138 and pumps it to a diverter assembly 156, e.g., which is positioned within sump 138 of dishwasher appliance. Diverter assembly 156 may include a diverter disk (not shown) disposed within a diverter chamber 158 for selectively distributing the wash fluid to the spray arm assemblies 134, 140, 142 and/or other spray manifolds or devices. For example, the diverter disk may have a plurality of apertures that are configured to align with one or more outlet ports (not shown) at the top of diverter chamber 158. In this manner, the diverter disk may be selectively rotated to provide wash fluid to the desired spray device.
According to an exemplary embodiment, diverter assembly 156 is configured for selectively distributing the flow of wash fluid from pump 152 to various fluid supply conduits, only some of which are illustrated in
The dishwasher 100 is further equipped with a controller 160 to regulate operation of the dishwasher 100. The 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 one embodiment, 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, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.
The controller 160 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, the controller 160 may be located within a control panel area 162 of door 116 as shown in
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
Referring now generally to
Drain pump assembly 200 may generally include a drain pump 202 which is in fluid communication with sump 138 and with an external drain 204 through a drain hose 206. During a drain cycle, drain pump 202 urges a flow of soiled wash fluid from sump 138, through drain hose 206 to external drain 204. More specifically, drain pump 202 comprises a drain pump impeller 208 rotatably mounted within a drain volute 210. Drain pump 202 includes a motor 212 which is energized during a drain cycle such that drain pump impeller 208 draws wash fluid from sump 138 and urges it through drain hose 206 to external drain 204. Notably, external drain 204 is typically positioned above drain pump 202 along the vertical direction V. Therefore, soiled wash fluid pumped out of drain volute 210 but which does not reach external drain 204 has a tendency to fall under the force of gravity back toward drain volute 210 when motor 212 stops rotating drain pump impeller 208.
Referring now generally to
Notably, as explained above, the tendency of soiled wash fluid to flow back into drain basin 220 can have a negative impact on the wash performance of dishwasher appliance 100. Therefore, according to an exemplary embodiment the present subject matter, dishwasher appliance 100 further includes a check valve assembly 230 which is generally configured for preventing the backflow of soiled wash fluid into drain basin 220 or sump 138. Specifically, check valve assembly 230 includes a check valve 232 that is removably positioned over discharge port 222 between drain pump 202 and drain basin 220.
In addition, check valve assembly 230 includes a positioning arm 234 which is attached to check valve 232 for positioning and locking check valve 232 in place over discharge port 222. According to the illustrated embodiment, check valve 232 comprises a resilient flap 240 that may pivot or flex between an open position to permit the flow of wash fluid and a closed position to prevent the flow of wash fluid. More specifically, as illustrated in
During operation, resilient flap 240 prevents wash fluid from flowing from drain volute 210 through discharge port 222 and into drain basin 220. In this regard, to enhance the sealing effect of resilient flap 240, discharge port 222 defines a sealing surface 242 that protrudes from drain basin 220 toward drain pump 202. When wash fluid tries to reverse flow into drain basin 220, resilient flap 240 and forms a seal with sealing surface 242. By contrast when motor 212 is energized, the flow of wash fluid will cause resilient flap 240 flexible pivot upward to an open position where wash fluid may flow freely.
Referring again generally to
Notably, dishwasher appliance 100 and sump 138 may define various features to facilitate the simple and effective installation and removal of check valve assembly 230. For example as best illustrated in
As best shown in
Positioning arm 234 and check valve 232 may be formed using any suitable material or materials. For example, because check valve 232 includes a resilient flap 240 and defines an auxiliary sealing surface 256, check valve 232 may preferably be formed using silicone or similar resilient rubber material. By contrast, because positioning arm 234 is used for installing or removing check valve 234, it is preferably formed from a rigid plastic material. According to an exemplary embodiment, positioning arm 234 is injection molded from a rigid plastic and then check valve 232 is over molded onto positioning arm 234 using silicone. In this manner, check valve assembly 230 is a single part that may be easily used to remove and install check valve 232.
As best illustrated in
In addition, drain basin 220 may define one or more soil management fins 274 for preventing the passage of large food particles or soil through discharge port 222, e.g., to prevent or minimize the potential for clogs. In this regard, soil management fins 274 extend from bottom wall 270 or recessed trough 272 upward along the vertical direction V and are positioned upstream of the discharge port 222. Notably, because soil management fins 274, discharge port 222, and check valve 232 create the largest restriction within the drain system of dishwasher appliance 100, clogs are more likely to form at this location than elsewhere within dishwasher appliance 100, such that they may be easily diagnosed and removed.
Referring again to
According to the illustrated embodiment, fine filter 282 is also used to lock check valve assembly 230 in position, as described below. In this regard, fine filter 282 defines an annular bottom support member 290 that is generally configured for locking positioning arm 234 and check valve 232 in position when seated against shoulder 250. Moreover, as shown in
According to the illustrated embodiment, sump wall 252 defines a recessed slot 294 that is configured for receiving positioning arm 234 such that it does not protrude into sump 138. Thus, positioning arm 234 may define a bend 296 which sits flush with shoulder 250 to prevent any interference with support member 290 seating on shoulder 250. According to an exemplary embodiment, to remove check valve assembly 230, a user would rotate fine filter 282 counterclockwise and pull up to remove it from sump 138. A user can then access screws (not shown) to remove coarse filter 280 from sump 138 before pulling up on positioning arm 234 to remove check valve assembly 230. After a clog is cleared, the process may be reversed for installing check valve assembly 230 and filters 280, 282.
Check valve assembly 130 described above is removable and is positioned upstream of the drain pump, e.g., between a discharge port of the drain basin and the drain volute. Notably, such positioning eliminates soiled wash fluid from flowing back into the drain basin where it would be recirculated within the wash chamber. In this regard, during a drain cycle, the flapper on the check valve is opened by the pressure of the flow of draining wash fluid. However, after the drain cycle is complete, the pressure from wash fluid remaining the high drain loop forces the flapper closed, thereby sealing the dishwasher from the previously drained soiled wash fluid.
In addition, check valve assembly 130 simplifies the removal of clogs when they occur. In this regard, clogs may be removed inside of the dishwasher instead of requiring the removal of the entire dishwasher from the cabinet. More specifically, the check valve can be accessed and clogs may be removed by opening the door, removing the fine filter and coarse filter to expose the check valve assembly in the sump, and removing clogs. After the check valve is removed, the clog may be easily cleared before reinstalling the check valve. Notably, because the discharge port of the drain basin is the tightest restriction on the drain system, the likelihood of clogs downstream of the check valve is minimal, thereby reducing the need for frequent service visits.
Additionally, by placing the check valve on the sump side of the drain pump, e.g., proximate the drain basin, the drain pump stays hydraulically primed, thereby minimizing the opportunity for the drain pump to become “air locked.” It also eliminates the need to pulse the drain pump on and off when activated to remove air from the volute of the drain pump, which improves sound quality. In sum, check valve assembly 100 described herein leads to better wash performance, improved efficiency, simplified maintenance, and improved user satisfaction.
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.
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