Washing apparatus and drain pump

Abstract

A pump ( 22 ) includes a pump casing ( 34 ) having a pump chamber ( 40 ), an impeller ( 30 ) received in the pump chamber ( 40 ), an electric motor ( 28 ) for driving the impeller ( 30 ), a detector ( 96 ) being configured for detecting a load on the pump ( 22 ), and a speed regulator ( 98 ) coupled to the detector. The speed regulator ( 98 ) is configured for decreasing the speed of the motor ( 28 ) to a speed greater than zero in response to the detector ( 96 ) detecting an unload condition of the drain pump ( 22 ).

1 . A washing apparatus, comprising:
 a washing chamber;   a water supply path for supplying fresh water to the washing chamber;   a drain path for discharging waste water in the washing chamber to the outside; and   a drain pump for removing the waste water via the drain path, the drain pump comprising:
 a pump casing having a pump chamber, an inlet and an outlet which are in fluid communication with the pump chamber; 
 an impeller received in the pump chamber; and 
 a brush direct current motor comprising:
 a rotor comprising a shaft coupled to the impeller, a rotor core fixed on the shaft, a commutator fixed on the shaft adjacent the rotor core, and rotor windings wound on the rotor core and electrically connected to the commutator; and 
 a stator comprising a magnetically conductive housing, at least one permanent magnet fixed to the housing, at least one pair of brushes making slide contact with the commutator, and at least two terminals for coupling an external direct current power supply to the brushes. 
 
   
     
     
         2 . The washing apparatus of  claim 1 , wherein further comprises:
 a detector being configured for detecting a load on the drain pump; and   a speed regulator coupled to the detector and being configured for decreasing the speed of the motor to a speed greater than zero in response to the detector detecting an unload condition of the drain pump.   
     
     
         3 . The washing apparatus of  claim 1 , wherein the impeller comprises a base plate and a plurality of curved vanes disposed on the base plate. 
     
     
         4 . The washing apparatus of  claim 3 , wherein the pump casing is in a spiral shape. 
     
     
         5 . The washing apparatus of  claim 4 , wherein the drain pump further comprises a macerator disposed in the pump chamber and fixed to the shaft of the motor. 
     
     
         6 . The washing apparatus of  claim 5 , wherein the pump casing comprises a side wall and a top wall forming an annular step, the inlet extending outwardly from the top wall and the outlet extending outwardly from the side wall. 
     
     
         7 . The washing apparatus of  claim 5 , wherein the brush direct current motor is a high voltage brush direct current motor with a direct current power between 50˜400 volt being supplied. 
     
     
         8 . The washing apparatus of  claim 5 , wherein the brush direct current motor is a low voltage brush direct current motor with a direct current power between 4-36 volt being supplied. 
     
     
         9 . The washing apparatus of  claim 8 , wherein the flow rate of the drain pump is smaller than 60 litres per minute. 
     
     
         10 . The washing apparatus of  claim 9 , wherein an outer diameter of the magnetically conductive housing is between 35 mm-60 mm and an output power of the brush direct current motor is smaller than 60 watts. 
     
     
         11 . A drain pump, comprising:
 a spiral volute having a pump chamber, an inlet and an outlet which are in fluid communication with the pump chamber;   an impeller received in the pump chamber and comprising a base plate and a plurality of curved vanes disposed on the base plate;   a macerator disposed in the pump chamber and fixed to the shaft; and   a brush direct current motor comprising:
 a rotor comprising a shaft coupled to the impeller, a rotor core fixed on the shaft, a commutator fixed on the shaft adjacent the rotor core, and rotor windings wound on the rotor core and electrically connected to the commutator; and 
 a stator comprising a magnetically conductive housing, at least one permanent magnet fixed to the housing, at least one pair of brushes making slide contact with the commutator, and at least two terminals for coupling an external direct current power supply to the brushes. 
   
     
     
         12 . The drain pump of  claim 11 , wherein further comprises:
 a detector being configured for detecting a load on the drain pump; and   a speed regulator coupled to the detector and being configured for decreasing the speed of the motor to a first speed greater than zero and smaller than a second speed when the detector detects the drain pump operates in a unload condition, the brush direct current motor operating in the second speed during a full load condition of the drain pump.   
     
     
         13 . The drain pump of  claim 11 , wherein the pump casing comprises a side wall and a top wall forming an annular step, the inlet extending outwardly from the top wall and the outlet extending outwardly from the side wall. 
     
     
         14 . The drain pump of  claim 11 , wherein the brush direct current motor is a high voltage brush direct current motor with a direct current power between 50˜400 volt being supplied. 
     
     
         15 . The drain pump of  claim 11 , wherein the brush direct current motor is a low voltage brush direct current motor with a direct current power between 4-36 volt being supplied. 
     
     
         16 . The drain pump of  claim 15 , wherein the flow rate of the drain pump is smaller than 60 liters per minute. 
     
     
         17 . The drain pump of  claim 16 , wherein an outer diameter of the magnetically conductive housing is between 35 mm-60 mm and an output power of the brush direct current motor is smaller than 60 watts. 
     
     
         18 . A pump, comprising:
 a pump casing having a pump chamber, an inlet and an outlet which are in fluid communication with the pump chamber;   an impeller received in the pump chamber;   an electric motor for driving the impeller;   a detector being configured for detecting a load on the pump; and   a speed regulator coupled to the detector and being configured for decreasing the speed of the motor to a first speed greater than zero and smaller than a second speed when the detector detects the pump operates in a unload condition, the brush direct current motor operating in the second speed during a full load condition of the pump.