Laundry treating appliance with method to reduce drum excursions

Abstract

A laundry treating appliance and method for reducing drum excursions associated with the forming a liquid inertial mass in the tub prior to an extraction phase during a cycle of operation.

1 . A method of operating a laundry treating appliance according to a cycle of operation, with the laundry treating appliance having a tub and a rotatable drum located within the tub, the method comprising:
 forming a liquid inertial mass in the tub by providing a predetermined amount of liquid to the tub; and   executing an extraction phase by accelerating rotational speed of the drum toward an extraction speed while the liquid inertial mass is in the tub at least for a portion of the extraction phase.   
     
     
         2 . The method of  claim 1  wherein the providing a predetermined amount of liquid to the tub comprises at least one of supplying liquid to or draining liquid from liquid already present in the tub until the predetermined amount is reached. 
     
     
         3 . The method of  claim 2  wherein the predetermined amount of liquid to the tub comprises a predetermined level in the tub. 
     
     
         4 . The method of  claim 3  wherein the predetermined level is below a level in the tub where rotation of the drum during the extraction phase would generate sufficient suds to cause suds lock. 
     
     
         5 . The method of  claim 3  wherein the predetermined level is below a level in the tub where rotation of the drum during the extraction phase would generate a water ring about the drum. 
     
     
         6 . The method of  claim 3  wherein the predetermined level is below the drum. 
     
     
         7 . The method of  claim 2  wherein the liquid already present in the tub comprises at least one of wash liquid and rinse liquid. 
     
     
         8 . The method of  claim 7  further comprising a wash phase preceding the extraction phase and the wash liquid is provided during the wash phase. 
     
     
         9 . The method of  claim 7  further comprising a rinse phase preceding the extraction phase and the rinse liquid is provided during the rinse phase. 
     
     
         10 . The method of  claim 1  wherein the liquid inertial mass is present in the tub when the rotational speed of the drum reaches a natural frequency of the drum during the extraction phase. 
     
     
         11 . The method of  claim 10  wherein the natural frequency corresponds to a pendulum mode of the drum. 
     
     
         12 . The method of  claim 11  further comprising removing the liquid inertial mass from the tub after the natural frequency corresponding to the pendulum mode of the drum and prior to the rotational speed of the drum reaching a natural frequency corresponding to a vertical travel mode of the drum during the extraction phase. 
     
     
         13 . The method of  claim 1  further comprising removing the liquid inertial mass from the tub prior to the rotational speed of the drum reaching a natural frequency corresponding to a vertical travel mode of the drum during the extraction phase. 
     
     
         14 . The method of  claim 13  wherein the liquid inertial mass is removed by draining the liquid inertial mass from the tub. 
     
     
         15 . A laundry treating appliance comprising:
 a chassis defining an interior;   a tub for holding liquid and located within the chassis interior;   a drum defining a laundry treating chamber, located within the tub, and rotatable about an axis of rotation;   a motor operably coupled to the drum to effect the rotation of the drum;   a suspension system coupling the tub to the chassis;   a liquid supply fluidly coupled to at least one of the tub and drum;   a liquid remover fluidly coupled to the tub; and   a controller operably coupled to and controlling the motor, liquid supply, and liquid remover to effect the formation of a liquid inertial mass in the tub by providing a predetermined amount of liquid to the tub, and accelerating rotational speed of the drum toward an extraction speed while the liquid inertial mass is in the tub.   
     
     
         16 . The laundry treating appliance of  claim 15  wherein the controller controls the liquid supply and liquid remover to ensure the presence of the liquid inertial mass when the rotational speed of the drum reaches a natural frequency of the drum corresponding to a pendulum mode of the drum. 
     
     
         17 . The laundry treating appliance of  claim 16  wherein the controller controls the liquid remover to remove the liquid inertial mass from the tub after the natural frequency corresponding to the pendulum mode of the drum and prior to the rotational speed of the drum reaching a natural frequency corresponding to a vertical travel mode of the drum during an extraction phase. 
     
     
         18 . The laundry treating appliance of  claim 17  further comprising a liquid level sensor operably coupled to the controller and the controller effects the providing of the predetermined amount of liquid to the tub by controlling the liquid supply and liquid remover until the liquid reaches a predetermined level in the tub as sensed by the liquid level sensor. 
     
     
         19 . The laundry treating appliance of  claim 16  wherein the axis of rotation is a vertical axis of rotation, and the suspension comprises multiple struts extending from the chassis to the tub.