Dishwasher with variable flow rate valve

Abstract

A dishwasher for treating dishes according to an automatic cycle of operation having a tub, a dish holder, a sprayer, a conduit coupled to the sprayer, a pump, and a variable flow rate valve fluidly coupling the pump to the conduits for supplying liquid to the sprayer during the automatic cycle of operation.

What is claimed is: 
     
         1 . A dishwasher for treating dishes according to an automatic cycle of operation, the dishwasher comprising:
 a tub at least partially defining a treating chamber for receiving dishes for treatment;   a first sprayer for spraying liquid in the treating chamber;   a first conduit fluidly coupled to the first sprayer and through which liquid may be supplied to the first sprayer;   a single-speed pump having an outlet and an inlet, with the inlet being fluidly coupled to the treating chamber;   a variable flow rate valve fluidly coupling the pump outlet to the first conduit; and   a controller configured to control the flow rate of the variable flow rate valve according to the automatic cycle of operation.   
     
     
         2 . The dishwasher of  claim 1  further comprising a second sprayer and a second conduit fluidly coupled to the second sprayer, with the variable flow rate valve being selectively coupled to one of the first and second conduits, with the controller configured to control the flow rate of the variable flow rate valve according to the selected one of the first and second sprayers. 
     
     
         3 . The dishwasher of  claim 1  wherein the single-speed pump comprises a single-phase motor. 
     
     
         4 . The dishwasher of  claim 3  wherein the single-phase motor comprises a synchronous motor. 
     
     
         5 . The dishwasher of  claim 1  wherein the variable flow rate valve comprises a diverter valve selectively fluidly coupling the pump outlet to an inlet of the first conduit. 
     
     
         6 . The dishwasher of  claim 5  wherein the diverter valve comprises a rotatable disk having at least one opening that may be aligned with the first conduit inlet to fluidly couple the pump to the first sprayer, wherein a degree of alignment of the opening with the first conduit inlet is controlled by the controller to control the flow rate through the diverter valve. 
     
     
         7 . The dishwasher of  claim 6  wherein the degree of alignment is a function of the noise generated by the pump during the cycle of operation. 
     
     
         8 . A method of treating dishes according to an automatic cycle of operation in a dishwasher having a tub at least partially defining a treating chamber, the method comprising:
 spraying liquid into the treating chamber through a first sprayer;   pumping the sprayed liquid from the treating chamber back to the first sprayer with a single-speed pump; and   controlling the flow rate of the liquid from the single-speed pump to the first sprayer according to the automatic cycle of operation by passing the liquid through a variable flow rate valve and setting the flow rate based on the cycle of operation.   
     
     
         9 . The method of  claim 8  wherein the controlling the flow rate of the liquid comprises controlling the flow rate of the liquid through the variable flow rate valve. 
     
     
         10 . The method of  claim 9  wherein the controlling the flow rate of the liquid comprises controlling a degree of alignment of an outlet of the variable flow rate valve with an inlet to a supply conduit supplying liquid to the first sprayer. 
     
     
         11 . The method of  claim 8  wherein the setting the flow rate based on the cycle of operation comprises setting the flow rate based on a degree of soil in the liquid. 
     
     
         12 . The method of  claim 8  wherein the setting the flow rate based on the cycle of operation comprises setting the degree of alignment of an outlet of the valve with an inlet to a supply conduit based on the cycle of operation. 
     
     
         13 . The method of  claim 8  further comprising pumping the sprayed liquid from the treating chamber back to one of the first sprayer and a second sprayer with the single-speed pump. 
     
     
         14 . The method of  claim 8  further comprising selectively coupling the variable flow rate valve to one of the first sprayer and the second sprayer, with the flow rate of the variable flow rate valve controlled according to the selected one of the first and second sprayer.