Washing maching appliance with a drain pump

Abstract

A washing machine appliance is provided. The washing machine appliance includes a wash basket rotatably mounted within a wash tub and a drain pump for removing liquid from the wash tub. During a spin cycle of the washing machine appliance, the drain pump may be activated during an acceleration portion of the spin cycle. Further, the drain pump may be operated at a first duty cycle for a first portion of a dwell step of the spin cycle and at a second duty cycle for a second portion of the dwell step of the spin cycle.

What is claimed is: 
     
         1 . A method for operating a washing machine appliance, the washing machine appliance having a cabinet with a wash tub mounted therein, the washing machine appliance also having a wash basket positioned within the wash tub, the wash basket configured for receipt of articles for washing and mounted for rotation relative to the cabinet, the method comprising:
 initiating a spin cycle of the washing machine appliance, the spin cycle comprising:
 an acceleration step in which the wash basket accelerates from a first angular velocity to a second angular velocity, the first angular velocity being different than the second angular velocity, the acceleration step of the spin cycle performed during an acceleration step time interval; 
 a dwell step in which the wash basket rotates at about the second angular velocity, the dwell step of the spin cycle performed during a dwell step time interval, the dwell step time interval comprising a first portion and a second portion; 
   running the drain pump of the washing machine appliance during the acceleration step of the spin cycle for about the acceleration step time interval;   operating the drain pump of the washing machine appliance at a first duty cycle during the dwell step of the spin cycle for about the first portion of the dwell step time interval; and   working the drain pump of the washing machine appliance at a second duty cycle during the dwell step of the spin cycle for about the second portion of the dwell step time interval.   
     
     
         2 . The method of  claim 1 , wherein the acceleration step and the dwell step of the spin cycle are substantially sequential. 
     
     
         3 . The method of  claim 1 , wherein the first duty cycle is greater than the second duty cycle. 
     
     
         4 . The method of  claim 1 , wherein the spin cycle of the washing machine appliance further comprises an additional acceleration step in which the wash basket accelerates from about the second angular velocity to a third angular velocity, the third angular velocity being different than the second angular velocity, the additional acceleration step of the spin cycle performed during an additional acceleration step time interval, and
 wherein the spin cycle of the washing machine appliance also further comprises an additional dwell step in which the wash basket rotates at about the third angular velocity, the additional dwell step of the spin cycle performed during an additional dwell step time interval, the additional dwell step time interval having a first portion and a second portion, the method further comprising the steps of:   running the drain pump of the washing machine appliance during the additional acceleration step of the spin cycle for about the additional acceleration step time interval;   operating the drain pump of the washing machine appliance at a third duty cycle during the additional dwell step of the spin cycle for about the first portion of the additional dwell step time interval; and   working the drain pump of the washing machine appliance at a fourth duty cycle during the additional dwell step of the spin cycle for about the second portion of the additional dwell step time interval.   
     
     
         5 . The method of  claim 4 , wherein the acceleration step, the dwell step, the additional acceleration step, and the additional dwell step of the spin cycle are substantially sequential. 
     
     
         6 . The method of  claim 4 , wherein the first duty cycle and the third duty cycle are about equal, and the second duty cycle and the fourth duty cycle are about equal. 
     
     
         7 . The method of  claim 4 , wherein the third duty cycle is greater than the fourth duty cycle. 
     
     
         8 . The method of  claim 1 , wherein the spin cycle of the washing machine appliance further comprises a brake step in which the wash basket accelerates from about second angular velocity to about a zero angular velocity, the zero angular velocity being different than the second angular velocity, the method further comprising the steps of:
 utilizing the drain pump of the washing machine appliance during the brake step of the spin cycle for a predetermined period of time.   
     
     
         9 . The method of  claim 8 , wherein the predetermined period of time is about thirty seconds. 
     
     
         10 . The method of  claim 1 , wherein the second angular velocity is between about eighty radians per second and about one hundred and ten radians per second. 
     
     
         11 . A washing machine appliance comprising:
 a cabinet;   a wash tub mounted within said cabinet, said wash tub configured for holding liquid during operation of the washing machine appliance;   a wash basket rotatably mounted within said wash tub, said wash basket configured for receipt of articles for washing;   a motor in mechanical communication with said wash basket such that said motor selectively rotates said wash basket;   a drain pump in fluid communication with said wash tub, said drain pump configured for selectively urging liquid out of said wash tub; and   a processing device in communication with said drain pump and said motor, said processing device configured for:
 initiating said motor during a spin cycle of the washing machine appliance, the spin cycle comprising:
 an acceleration step in which said motor accelerates said wash basket from a first angular velocity to a second angular velocity, the first angular velocity being different than the second angular velocity, the acceleration step of the spin cycle performed during an acceleration step time interval; 
 a dwell step in which said motor rotates said wash basket at about the second angular velocity, the dwell step of the spin cycle performed during a dwell step time interval, the dwell step time interval having a first portion and a second portion; 
 
 running said drain pump during the acceleration step of the spin cycle for about the acceleration step time interval; 
 operating said drain pump at a first duty cycle during the dwell step of the spin cycle for about the first portion of the dwell step time interval; and 
 working said drain pump at a second duty cycle during the dwell step of the spin cycle for about the second portion of the dwell step time interval. 
   
     
     
         12 . The washing machine appliance of  claim 11 , wherein the acceleration step and the dwell step of the spin cycle are substantially sequential. 
     
     
         13 . The washing machine appliance of  claim 11 , wherein the first duty cycle is greater than the second duty cycle. 
     
     
         14 . The washing machine appliance of  claim 11 , wherein the spin cycle of the washing machine appliance further comprises an additional acceleration step in which said motor accelerates said wash basket from about the second angular velocity to a third angular velocity, the third angular velocity being different than the second angular velocity, the additional acceleration step of the spin cycle performed during an additional acceleration step time interval, and
 wherein the spin cycle of the washing machine appliance also further comprises an additional dwell step in which said motor rotates said wash basket at about the third angular velocity, the additional dwell step of the spin cycle performed during an additional dwell step time interval, the additional dwell step time interval having a first portion and a second portion, said processing device further configured for:   running said drain pump during the additional acceleration step of the spin cycle for about the additional acceleration step time interval;   operating said drain pump at a third duty cycle during the additional dwell step of the spin cycle for about the first portion of the additional dwell step time interval; and   working said drain pump at a fourth duty cycle during the additional dwell step of the spin cycle for about the second portion of the additional dwell step time interval.   
     
     
         15 . The washing machine appliance of  claim 14 , wherein the acceleration step, the dwell step, the additional acceleration step, and the additional dwell step of the spin cycle are substantially sequential. 
     
     
         16 . The washing machine appliance of  claim 14 , wherein the first duty cycle and the third duty cycle are about equal, and the second duty cycle and the fourth duty cycle are about equal. 
     
     
         17 . The washing machine appliance of  claim 14 , wherein the third duty cycle is greater than the fourth duty cycle. 
     
     
         18 . The washing machine appliance of  claim 11 , wherein the spin cycle of the washing machine appliance further comprises a brake step in which the wash basket accelerates from about the second angular velocity to about a zero angular velocity, the zero angular velocity being different than the second angular velocity, said processing device further configured for:
 utilizing said drain pump during the brake step of the spin cycle for a predetermined period of time.   
     
     
         19 . The washing machine appliance of  claim 18 , wherein the predetermined period of time is about thirty seconds. 
     
     
         20 . The washing machine appliance of  claim 11 , wherein the second angular velocity is between about eighty radians per second and about one hundred and ten radians per second.