Electric water pump with coolant passage

Abstract

An electric water pump includes an electric motor having a stator which generates an electromagnetic field by control signals supplied from a pump driver. A rotor rotates by the electromagnetic field generated by the stator. An impeller is connected to and rotates with the rotor to circulate a coolant. An inside space of the electric water pump may include a motor room in which the electric motor is disposed, a volute room in which the impeller is positioned, and a pump driver room in which the pump driver is positioned.

What is claimed is: 
     
         1 . An electric water pump comprising:
 an electric motor having a stator which generates an electromagnetic field by control signals supplied from a pump driver, and a rotor which rotates by the electromagnetic field generated by the stator; and   an impeller connected to and rotating with the rotor to circulate a coolant,   wherein an inside space of the electric water pump includes:
 a motor room in which the electric motor is disposed; 
 a volute room in which the impeller is disposed; and 
 a pump driver room in which the pump driver is disposed. 
   
     
     
         2 . The electric water pump of  claim 1 , further comprising:
 a bulkhead separating the motor room and the pump driver room to seal the motor room and the pump driver room with respect to each other;   a separation wall separately forming a rotor room inside the motor room to isolate the rotor from the motor room; and   a cap mounted to a front surface of the bulkhead to support one end of the separation wall,   wherein a front side of the rotor room fluidly communicates with the volute room to flow the coolant into the rotor room.   
     
     
         3 . The electric water pump of  claim 2 , further comprising:
 an insulation pad for insulating the pump driver from the bulkhead.   
     
     
         4 . The electric water pump of  claim 2 , further comprising:
 a first cooling passage formed in one side of a water pump housing or a motor room cover for sealing the motor room from outside;   a second cooling passage of which one end is connected to the first cooling passage, the second cooling passage penetrating the bulkhead; and   a third cooling passage connected to another end of the second cooling passage and formed in another side of the water pump housing or the motor room cover,   wherein a portion of the coolant passing through the volute room flows through the first cooling passage, the second cooling passage, and the third cooling passage.   
     
     
         5 . The electric water pump of  claim 4 , wherein
 the first cooling passage and the third cooling passage are formed in a length direction of the electric water pump.   
     
     
         6 . The electric water pump of  claim 4 , wherein
 the second cooling passage passes through a middle of the bulkhead.   
     
     
         7 . The electric water pump of  claim 4 , wherein
 at least one coolant flow passage is integrally formed by the first cooling passage, the second cooling passage, and the third cooling passage.   
     
     
         8 . The electric water pump of  claim 1 , wherein the volute room has an inlet and outlet through which the coolant flows by rotation of the impeller and flows out.