Pump

Abstract

A centrifugal pump for a kitchen appliance has a pump head and a pump body having a motor. The stator of the motor has a stator core, windings and an end cap fixed to one side of the stator core. The pump head has a volute and an impeller. The volute has a chamber with an inlet and an outlet. The chamber has an opening facing the pump body. The end cap is made of thermally conductive material and has an annular sidewall and a base plate. The sidewall surrounds the stator core. The base plate seals the opening of the chamber. Heat generated by the stator is transferred to liquid in the chamber via the end cap to cool the motor and to heat the liquid.

1 . A centrifugal pump comprising
 a pump body incorporating a motor, the motor comprising a stator and a rotor rotatably mounted to the stator, the stator comprises a stator core and windings and the rotor comprises a shaft;   a pump head mounted to the pump body, the pump head comprising a volute and an impeller disposed within the volute; the volute forming a chamber having an inlet and an outlet; the chamber has an opening facing the pump body;   wherein the motor comprises an end cap made of thermally conductive material and mounted to an axial end of the stator core, the end cap comprising an annular sidewall disposed around the stator core and a base plate connected with the annular sidewall, the base plate covering the opening of the chamber to transfer heat generated by the stator to liquid inside the chamber.   
     
     
         2 . The centrifugal pump of  claim 1 , wherein the opening of the chamber is sealed by the base plate. 
     
     
         3 . The centrifugal pump of  claim 1 , wherein the base plate and the annular sidewall are formed as a monolithic structure. 
     
     
         4 . The centrifugal pump of  claim 1 , wherein the end cap comprises a hub having a bearing supporting the shaft. 
     
     
         5 . The centrifugal pump of  claim 1 , wherein the base plate has a stepped recess accommodating a rotatable seal between the base plate and the shaft. 
     
     
         6 . The centrifugal pump of  claim 5 , wherein the hub forms a compartment open toward the rotatable seal and a water slinger is fixed to the shaft and disposed within the compartment and a channel connects the compartment with a drain hole formed in the sidewall. 
     
     
         7 . The centrifugal pump of  claim 1 , wherein the outer surface of the annular sidewall is provided with a thermal insulating layer. 
     
     
         8 . The centrifugal pump of  claim 1 , wherein the pump body is further provided with an annular shield surrounding the outer surface of the annular sidewall. 
     
     
         9 . The centrifugal pump of  claim 8 , wherein the end cap is provided with a thermal insulating layer disposed between the annular shield and the annular sidewall. 
     
     
         10 . The centrifugal pump of  claim 1 , wherein both the annular sidewall and the connection between the annular sidewall and the base plate are airtight. 
     
     
         11 . The centrifugal pump of  claim 1 , wherein a part of an outer surface of the stator core is covered by the annular sidewall and another part of the outer surface of the stator core is exposed to the air. 
     
     
         12 . The centrifugal pump of  claim 1 , wherein an axial end of the annular sidewall remote from the base plate is formed with a step in its inner surface and the stator core mates with the step. 
     
     
         13 . A kitchen appliance comprising: an inlet pipe; an outlet pipe; a circulation path; and the centrifugal pump of  claim 1 , wherein the pump is arranged to heat a liquid while moving the liquid along the circulation path. 
     
     
         14 . The kitchen appliance of  claim 13 , wherein the annular sidewall is in thermal contact with the stator core. 
     
     
         15 . The kitchen appliance of  claim 13 , wherein the end cap comprises a hub having a bearing supporting the shaft. 
     
     
         16 . The kitchen appliance of  claim 13 , wherein the base plate has a stepped recess accommodating a rotatable seal between the base plate and the shaft. 
     
     
         17 . The kitchen appliance of  claim 16 , wherein the hub forms a compartment open toward the rotatable seal and a water slinger is fixed to the shaft and disposed within the compartment and a channel connects the compartment with a drain hole formed in the sidewall. 
     
     
         18 . The kitchen appliance of  claim 13 , wherein the outer surface of the annular sidewall is provided with a thermal insulating layer. 
     
     
         19 . The kitchen appliance of  claim 13 , wherein the pump body is further provided with an annular shield surrounding the radially outer surface of the annular sidewall. 
     
     
         20 . The kitchen appliance of  claim 19 , wherein the end cap is provided with a thermal insulating layer disposed between the annular shield and the annular sidewall. 
     
     
         21 . The kitchen appliance of  claim 13 , wherein an axial end of the annular sidewall remote from the base plate is formed with a step and the stator core mates with the step. 
     
     
         22 . The kitchen appliance of  claim 13 , wherein the kitchen appliance is a dishwasher.