Integrated Washing Machine Pump

Abstract

A drain pump (and/or recirculating pump) for a clothes washing machine which has no dynamic leak paths exterior to the washing machine outer bowl. The pump is contained within a housing which is either formed integrally with the outer bowl or connects directly within an aperture provided in the bottom of the bowl using a single static seal. The pump inlet is directly exposed to the interior of the outer bowl. The pump motor has a rotor mounted within the pump housing with the interconnected pump impeller to obviate the need for a dynamic water seal for the rotor drive shaft. The rotor can run wet. The stator is mounted outside of the housing such that the housing wall lies in the motor air gap. The motor is preferably a brushless dc motor.

1 . A clothes washing machine comprising: 
 a stationary watertight outer bowl which in use may selectively contain wash or rinse liquid,    a perforated tub which receives the clothes load mounted within said outer bowl,    means for selectively agitating or spinning the clothes load within said perforated tub,    a rotary pump for pumping wash water or rinse water from said outer bowl, said pump having: 
 a housing integrally formed in the wall of said outer bowl,  
 a motor rotor rotatably mounted within said housing,  
 an impeller mounted within said housing and connected to said rotor,  
 said housing being open to the interior of said outer bowl to provide an inlet to said pump,  
 and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator.  
   
   
   
       2 . A clothes washing machine comprising: 
 a stationary outer bowl which in use may selectively contain wash or rinse liquid,    said outer bowl having an aperture in the bottom,    a perforated tub which receives the clothes load mounted within said outer bowl,    means for selectively agitating or spinning the clothes load within said perforated tub,    a rotary pump for pumping wash water or rinse water from said outer bowl, said pump having: 
 a housing which is sealably mounted within said aperture in said outer bowl to be integral with said outer bowl,  
 a motor rotor rotatably mounted within said housing,  
 an impeller mounted within said housing and connected to said rotor,  
 said housing being open to the interior of said outer bowl to provide an inlet to said pump,  
 and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator.  
   
   
   
       3 . A pump for a clothes washing machine having a water containing outer bowl which drains and/or recirculates liquid in said bowl, said bowl having an aperture in the bottom and said pump having a housing which includes an electric motor, comprising: 
 a housing adapted to be sealably mounted within an aperture in said outer bowl,    an electric motor rotor rotatably mounted within said housing,    an impeller mounted within said housing and connected to said rotor,    said housing in use being open to the interior of said outer bowl to provide an inlet to said pump,    and a motor stator being mounted about the exterior surface of said housing in co-acting relationship with said rotor such that the housing wall lies between said rotor and said stator.    
   
   
       4 . A clothes washing machine according to any one of  claims 1  to  3  wherein said rotor includes a drive shaft and said impeller is mounted on said drive shaft.  
   
   
       5 . A clothes washing machine according to  claim 4  wherein a transverse partition is mounted in said housing which separates said rotor and said impeller into two compartments and which contains a waterproof bearing in a central aperture through which said drive shaft passes and is journalled.  
   
   
       6 . A clothes washing appliance according to  claim 5  wherein said impeller is mounted within said housing proximate to said outer bowl and said rotor is mounted in said housing distal to said outer bowl.  
   
   
       7 . A clothes washing appliance according to  claim 6  wherein said partition has a small aperture therein which allows wash liquid to enter the rotor compartment and to vent pneumatic pressure in said rotor compartment.  
   
   
       8 . A clothes washing appliance according to  claim 7  wherein a filter is located in said aperture to prevent foreign bodies entrained in said wash liquid from entering said rotor compartment.  
   
   
       9 . A clothes washing appliance according to  claim 1  wherein said distal portion of said housing has a cylindrical wall and said cylindrical wall lies between said stator and said rotor.  
   
   
       10 . A clothes washing appliance according to  claim 2  wherein said distal portion of said housing has a cylindrical wall and said cylindrical wall lies between said stator and said rotor.  
   
   
       11 . A clothes washing appliance according to  claim 3  wherein said distal portion of said housing has a cylindrical wall and said cylindrical wall lies between said stator and said rotor.  
   
   
       12 . A clothes washing machine as claimed in any one of  claims 1  to  3  wherein said pump motor is a brushless dc motor.