Patent Application
20200253455
The subject matter of the present disclosure relates generally to dishwasher appliances, and more particularly to fluid circulation systems within dishwasher appliances and related methods.
Dishwasher appliances generally include a tub that defines a wash compartment. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Spray assemblies within the wash chamber can apply or direct wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Multiple spray assemblies can be provided including, e.g., a lower spray arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray arm assembly mounted to one of the rack assemblies, and/or an upper spray assembly mounted to the tub at a top of the wash chamber.
Dishwasher appliances further typically include a fluid circulation system which is in fluid communication with the spray assemblies for circulating fluid to the spray assemblies. Such fluid circulation systems generally include a filter and a pump downstream of the filter, e.g., the pump and the filter are positioned such that generally all wash fluid flowed to the pump is flowed through the filter. The fluid circulation system generally receives fluid from the wash chamber, filters soil from the fluid, and flows the filtered fluid to the spray assemblies. Additionally, unfiltered fluid can be flowed to a drain as required.
However, excess soil that remains on the filter can block such fluid flow. Accordingly, cleaning of the filter to prevent such blockages during operation is desired. One solution is to actively spray fluid at the filter to remove the soil therefrom. For example, the fluid circulation system may be operable in at least two modes, a wash mode where fluid is pumped into and through the wash compartment and a filter cleaning mode where fluid is sprayed onto the filter. The fluid circulation system may be selectively operable in one of the two or more various modes based at least in part on a position of a diverter. Typically, an electronic position sensor is included in the fluid circulation system to allow the dishwasher appliance, such as a controller thereof, to determine the position of the diverter and thereby determine which operating mode, e.g., wash mode or filter cleaning mode, is active.
However, such electronic position sensors may introduce additional complexity to the fluid circulation system. For example, multiple wires are typically routed to the position sensor, resulting in additional complexity and part count of the fluid circulation system than would otherwise be present, e.g. without the electronic position sensor. Moreover, such wires must also run outside of the wet portion of the dishwasher appliance, e.g., to the controller, creating potential leak points where the wiring passes through.
Accordingly, improved methods of operating a dishwasher appliance and/or determining a position of a diverter in a dishwashing appliance are desired. In particular, methods wherein the use of electronic position sensors is not required would be advantageous.
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 accordance with one embodiment, a method of operating a dishwasher appliance is provided. The dishwasher appliance includes a tub that defines a wash chamber and a sump positioned below the wash chamber to receive fluid from the wash chamber. The method includes circulating fluid through the wash chamber with a fluid circulation system. The fluid circulation system includes a pump, a filter upstream of the pump, and a diverter downstream of the pump. Circulating fluid through the wash chamber includes pumping fluid from the sump into the wash chamber via a first component when the diverter is in a first position. The method also includes cleaning the filter by pumping the fluid from the sump to a filter cleaning manifold when the diverter is in a second position. The method includes measuring a fluid pressure in the sump with a pressure sensor while circulating the fluid and cleaning the filter. The method further includes determining whether the diverter is in the second position based on the measured fluid pressure.
In accordance with another embodiment, a method of determining a position of a diverter of a fluid circulation system in a dishwasher appliance is provided. The method includes measuring a fluid pressure in a sump of the dishwasher appliance while pumping fluid from the sump into a wash chamber of the dishwasher appliance via a first component when the diverter is in a first position. The method also includes measuring the fluid pressure in the sump of the dishwasher appliance while pumping the fluid from the sump to a filter cleaning manifold when the diverter is in a second position. The method further includes determining whether the diverter is in the second position based on the measured fluid pressure.
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.
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 “fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include additives such as e.g., detergent or other treatments.
As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows. The term “radially” refers to the relative direction that is substantially perpendicular to an axial centerline of a particular component, the term “axially” refers to the relative direction that is substantially parallel and/or coaxially aligned to an axial centerline of a particular component and the term “circumferentially” refers to the relative direction that extends around the axial centerline of a particular component.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, terms of approximation, such as “generally,” or “about” include values within ten percent greater or less than the stated value. When used in the context of an angle or direction, such terms include within ten degrees greater or less than the stated angle or direction. For example, “generally vertical” includes directions within ten degrees of vertical in any direction, e.g., clockwise or counter-clockwise.
Upper and lower guide rails 124, 126 are mounted on tub side walls 128 and accommodate roller-equipped rack assemblies 130 and 132. Each of the rack assemblies 130, 132 is fabricated into lattice structures including a plurality of elongated members 134 (for clarity of illustration, not all elongated members making up assemblies 130 and 132 are shown in
The dishwasher appliance 100 further includes a lower spray-arm assembly 144 that is rotatably mounted within a lower region 146 of the wash chamber 106 and above a bottom wall 142 of the tub 104 so as to rotate in relatively close proximity to rack assembly 132. A mid-level spray-arm assembly 148 is located in an upper region 147 of the wash chamber 106 and may be located in close proximity to upper rack 130. Additionally, an upper spray assembly 150 may be located above the upper rack 130.
Each spray assembly 144, 148, 150 may include a spray arm or other sprayer and a conduit in fluid communication with the sprayer. For example, mid-level spray-arm assembly 148 may include a spray arm 160 and a conduit 162. Lower spray-arm assembly 144 may include a spray arm 164 and a conduit 166. Additionally, upper spray assembly 150 may include a spray head 170 and a conduit 172 in fluid communication with the spray head 170. Each spray assembly 144, 148, 150 includes an arrangement of discharge ports or orifices for directing washing liquid received from diverter 300 (See, e.g.,
The lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150 are part of a fluid circulation system 152 for circulating fluid in the dishwasher appliance 100. The fluid circulation system 152 also includes various components for receiving fluid from the wash chamber 106, filtering the fluid, and flowing the fluid to the various spray assemblies such as the lower and mid-level spray-arm assemblies 144, 148 and the upper spray assembly 150.
Each spray assembly 144, 148, 150 may receive an independent stream of fluid, may be stationary, and/or may be configured to rotate in one or both directions. For example, a single spray arm may have multiple sets of discharge ports, each set receiving wash fluid from a different fluid conduit, and each set being configured to spray in opposite directions and impart opposite rotational forces on the spray arm. In order to avoid stalling the rotation of such a spray arm, wash fluid is typically only supplied to one of the sets of discharge ports at a time.
The dishwasher appliance 100 is further equipped with a controller 137 to regulate operation of the dishwasher appliance 100. The controller 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.
The controller 137 may be positioned in a variety of locations throughout dishwasher appliance 100. In the illustrated embodiment, the controller 137 may be located within a control panel area 121 of door 120 as shown in
It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher. The exemplary embodiment depicted in
Referring now to
Sump 200 may additionally include a skirt 209. The skirt 209 may extend from the sidewall 204, such as from the top end 206, away from the chamber 202 and away from a filter 250 disposed at least partially within the chamber 202 (as discussed herein). For example, the skirt 209 may extend generally perpendicularly to sidewall 204 and/or generally radially from the sidewall 204. As noted above, generally perpendicular is understood to include forming an angle within ten degrees of perpendicular, e.g., from eighty degrees to one hundred degrees, similarly, generally radial includes within ten degrees of radial. Fluid flowing into the chamber 202 may flow along skirt 209 until the skirt 209 reaches the sidewall 204, and the fluid may then flow into the chamber 202. Skirt 209 may, for example, be mounted to bottom wall 142.
System 152 may further include a pump 210 which provides pressurized fluid flow to a diverter 300 via a conduit 220. Pump 210 may include an impeller 212 which is disposed within the chamber 202. In some embodiments, the impeller 212 may be enclosed within a housing 211, and the housing 211 may include an intake 213 for drawing fluid into pump 210, e.g., to the impeller 212. Pump 210 may further include a motor 214 and a shaft 216 which connects the motor 214 and impeller 212. For example, the motor 214 may be disposed within the chamber 202, and may be hermetically sealed to prevent damage thereto from fluids within the chamber 202. Alternatively, the shaft 216 may extend through the base wall 208, and the motor 214 may be external to the chamber 202. Impeller 212 may spin within the chamber 202 when activated by the motor 214 to influence the flow of fluid within the chamber 202.
As further illustrated, a filter 250 may be disposed at least partially within the chamber 202. As shown, the filter 250 surrounds the impeller 212, and can additionally surround other components of the pump 210 such as the motor 214. As illustrated, a filter 250 in accordance with the present disclosure may include a sidewall 252. Filter 250 may further include a top wall 254. Still further, filter 250 may include a base wall 255. The sidewall 252 may extend generally along the vertical direction V, e.g., within 10 degrees of vertical, and between the top wall 254 and bottom wall 255. Accordingly, the filter 250 may define an unfiltered volume 244 and a filtered volume 246 within the sump chamber 202. That is, the unfiltered volume 244 may be the portion of sump chamber 202 upstream of the filter 250 with respect to a primary flow direction and the filtered volume 246 may be the portion of sump chamber 202 downstream of the filter 250 with respect to the primary flow direction. Further, it is understood that the unfiltered volume 244 is unfiltered relative to the filter 250. In some embodiments, the sidewall 252 may have a generally circular cross-sectional shape. Alternatively, the sidewall 252 may have a generally rectangular or other suitable polygonal cross-sectional shape, with multiple linear or curvilinear portions.
The sidewall 252 may include a filter media defining an outer surface 257 and an inner surface 258 of the sidewall 252. Some embodiments may include filter media, e.g., screen or mesh, having pore or hole sizes in the range of about four thousandths (0.004 or 4/1000) of an inch to about eighty thousandths (0.08 or 80/1000) of an inch in diameter, or the pores may otherwise be sized and shaped to allow fluid flow therethrough, while preventing the flow of soil therethrough, thus filtering the fluid as the fluid flows into the filter 250 through the walls thereof.
As further illustrated, system 152 may further include a cleaning manifold 270. The cleaning manifold may be configured to provide fluid to the outer surface 257 of the filter sidewall 252 for cleaning of the sidewall 252. In particular, fluid flowing through the outlet conduit 220 may, as discussed herein below, be diverted to the manifold 270. The fluid in the manifold 270 may then flow from the manifold 270 towards and onto the outer surface 257. The flow of fluid onto and on the outer surface 257 may advantageously clean the sidewall 252 by dislodging and removing soil from the sidewall 252. In exemplary embodiments, the fluid exhausted from the cleaning manifold 270 may be exhausted in a plurality of streams, which may for example, be relatively high velocity jets of fluid, towards the outer surface 257. The fluid may, for example, be exhausted generally along the vertical direction V onto the outer surface 257, and may flow generally along the vertical direction V (e.g., generally parallel to the outer surface 257) to clean the sidewall 252.
Cleaning manifold 270 may be disposed proximate the outer surface 257, and may for example wrap around at least a portion of the perimeter of the sidewall 252. As illustrated, manifold 270 may for example contact the outer surface 257. Further, in exemplary embodiments, manifold 270 may be disposed proximate the top wall 254. A plurality of apertures 272 may be defined in the manifold 270 for flowing fluid therethrough. Each aperture 272 may be oriented to direct fluid exhausted therefrom towards the outer surface 257. For example, fluid exhausted from each aperture 272 may be flowed generally along the vertical direction V and along the outer surface 257.
System 152 may further include a diverter 300. Diverter 300 may be configured for selectively flowing fluid to the wash chamber 106 (such as via one or more of the spray assemblies) or to the cleaning manifold 270, depending on the position of the valve 310. Use of such a diverter 300 in accordance with the present disclosure may advantageously provide improved cleaning of the filter 250 without requiring an increase in water usage or an increase in energy usage or motor size. Such improved cleaning is provided by, for example, selective diversion of the fluid to the cleaning manifold 270 for periodic amounts of time to clean the filter 250, such as the sidewall 252 thereof, as needed. Further, the diverter 300 may advantageously only be utilized to divert fluid to the cleaning manifold 270 when cleaning is needed, and may automatically select between flowing fluid to the wash chamber 106 (such as via one or more of the spray assemblies) or to the cleaning manifold 270.
As best seen in
By way of example, first outlet 303 can be fluidly connected with upper spray assembly 150 and lower spray arm assembly 144 and second outlet 304 can be fluidly connected with mid-level spray arm assembly 148. Third outlet 305 may be fluidly connected with another fluid-using component, e.g., for cleaning silverware. Fourth outlet 306 may be fluidly connected to cleaning manifold 270. Other spray assemblies and connection configurations may be used as well. As such, the rotation of valve 310 in diverter 300 can be used to selectively place pump 210 in fluid communication with spray assemblies 144, 148, or 150, another fluid-using component, or cleaning manifold 270, by way of outlets 303, 304, 305, and 306. Thus, the dishwasher appliance 100 may be operable in various mode depending on the position of the diverter 300 and/or the valve 310 of the diverter 300, e.g., a wash mode when the valve 310 is positioned to divert fluid to one or more of the spray assemblies 144, 148, and/or 150, or a filter cleaning mode when the valve 310 is positioned to divert the fluid to the manifold 270.
In other embodiments of the invention, two, three, or more than four outlets may be provided in diverter 300 depending upon e.g., the number of switchable outlets desired for selectively placing pump 210 in fluid communication with different fluid-using elements of appliance 100. For example, in some embodiments, the plurality of outlets may include a first outlet and a second outlet, the second outlet in fluid communication with the cleaning manifold 270. In some embodiments, the first outlet may be in fluid communication with one or more spray assemblies 144, 148, and/or 150, such as lower spray arm assembly 144 and/or upper spray assembly 150. Also, some embodiments of the plurality of outlets may further include a third outlet in fluid communication with others of the spray assemblies 144, 148, and/or 150, such as mid-level spray arm 148. As used herein, the terms “first,” “second,” and “third” do not necessarily denote order or sequence, e.g., in the foregoing example embodiments, the diverter may be configured to provide flow to the third outlet before the second outlet.
Referring still to
In interest of brevity, the exemplary diverter 300 is only described generally. For more detail, exemplary diverters are described in U.S. application Ser. No. 15/460,298 (U.S. 2018/0263458 A1) and U.S. application Ser. No. 15/470,963 (U.S. 2018/0279850 A1) both of John Edward Dries, both of which are incorporated herein by reference in their entirety.
Referring now specifically to
Turning now to
In some embodiments, for example as illustrated in
As discussed above, determining that the diverter 300 is in the second position may also include determining that the dishwashing appliance 100 is in a filter cleaning mode. Additionally, the second position may be referred to as a “home” position of the diverter 300 and the determination that the diverter 300 is in the home position may be, e.g., recorded or stored in a memory of the controller 137, and various other positions of the diverter 300 may be determined or inferred with reference to the home position. For example, the diverter 300 may be configured to move to the first position, e.g., a position where fluid is supplied to the mid-level spray-arm assembly 148, after the home position when the pump 210 is cycled (e.g., deactivated and reactivated and/or a speed of the pump 210 is decreased and then increased), and in such embodiments exemplary methods may include inferring that the diverter 300 is in the position where fluid is supplied to the mid-level spray-arm assembly 148 after determining that the diverter 300 is in the home position and after a subsequent pump cycle following the determination that the diverter 300 is in the home position. Thus, at least some exemplary embodiments of the method 400 may include determining the diverter 300 is in the first position after determining the diverter is in the second position at step 440 and after the pump 210 has subsequently deactivated and then reactivated.
In some embodiments, the step 440 of determining whether the diverter 300 is in the second position based on the measured fluid pressure may include determining that the diverter 300 is in the second position when the measured fluid pressure increases, e.g., as illustrated in
In some embodiments, the step 440 of determining whether the diverter 300 is in the second position based on the measured fluid pressure may include obtaining at least two pressure values, e.g., a first measured pressure value and a second measured pressure value, which may be obtained with the pressure sensor 260, for example. In such embodiments, determining whether the diverter 300 is in the second position based on the measured fluid pressure may include determining that the diverter 300 is in the second position at the time the second measured pressure value is obtained based on the second measured pressure value being greater than the first measured pressure value.
In various embodiments, the diverter 300 may include two or more outlets, as discussed above. Thus, in some embodiments of the method 400, the first component may be a first spray arm, e.g., lower spray-arm assembly 144, and the step 410 of circulating the fluid may include circulating the fluid through a lower portion 146 of the wash chamber. In such embodiments, the method 400 may further include circulating the fluid through an upper portion 147 of the wash chamber 106 by pumping the fluid from the sump 200 into the wash chamber 106 via a second spray arm, e.g., mid-level spray-arm assembly 148 and/or upper spray assembly 150, when the diverter 300 is in a third position.
As mentioned above, features of multiple embodiments may be combined in various ways to provide additional embodiments. For example, aspects of the foregoing examples may be combined such that additional embodiments of method 400 may include determining the diverter 300 is in the first position after determining the diverter 300 is in the second position and the pump 210 has subsequently deactivated and then reactivated, and may further include determining the diverter 300 is in the third position after determining the diverter 300 is in the first position and the pump 210 has subsequently deactivated and then reactivated.
As described above in the context of
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.
