Method for manufacturing stator for electric water pump

Abstract

A method for manufacturing a stator for an electric water pump may be used for manufacturing the stator used in the electric water pump. In the electric water pump which includes stator assembly for an electric water pump, wherein the stator assembly including a plurality of core-insulator assemblies generates a magnetic field according to a control signal and a rotor is rotated by the magnetic field generated at the stator assembly to pressurize coolant, the method for manufacturing the stator assembly may include a) stacking a plurality of pieces made of a magnetic material to form a core stack, b) molding an insulator to the core stack, c) coiling a coil to the insulator to form a core-insulator assembly so as to form a magnetic path, and d) connecting the respective core-insulator assembly in an annular shape in sequence to form the stator assembly.

What is claimed is: 
     
         1 . A method for manufacturing a stator assembly for an electric water pump, wherein the stator assembly including a plurality of core-insulator assemblies generates a magnetic field according to a control signal and a rotor is rotated by the magnetic field generated at the stator assembly to pressurize coolant, the method for manufacturing the stator assembly comprising:
 a) stacking a plurality of pieces made of a magnetic material to form a core stack;   b) molding an insulator to the core stack;   c) coiling a coil to the insulator to form a core-insulator assembly so as to form a magnetic path; and   d) connecting the respective core-insulator assembly in an annular shape in sequence to form the stator assembly.   
     
     
         2 . The method of  claim 1 , further comprising forming a mounting groove and a mounting protrusion to the insulator with the step b) or between the steps of b) and c). 
     
     
         3 . The method of  claim 1 , further comprising molding a stator case to the respective core-insulator assembly and the coil after the step d). 
     
     
         4 . The method of  claim 3 , wherein the stator case is made of a bulk mold compound including a potassium family that has a low coefficient of contraction. 
     
     
         5 . The method of  claim 1 , wherein the pieces respectively have an exterior circumferential portion, an interior circumferential portion, and a connecting portion extending radially in order to connect the exterior circumferential portion to the interior circumferential portion, and
 wherein the insulator has an exterior circumferential portion wrapping the exterior circumferential portion of the pieces, an interior circumferential portion wrapping the interior circumferential portion of the pieces, and a connecting portion wrapping the connecting portion of the pieces and connecting the exterior circumferential portion of the insulator to the interior circumferential portion of the insulator.   
     
     
         6 . The method of  claim 5 , wherein circumferential thickness of the connecting portion in the pieces is smaller than those of the exterior circumferential portion and the interior circumferential portion in the pieces. 
     
     
         7 . The method of  claim 5 , wherein one side of the interior circumferential portion of the insulator is provided with a mounting groove and the other side of the interior circumferential portion of the insulator is provided with a mounting protrusion. 
     
     
         8 . The method of  claim 7 , wherein the plurality of core-insulator assemblies are connected with each other by inserting the mounting protrusion of one core-insulator assembly in the mounting groove of the other core-insulator assembly. 
     
     
         9 . The method of  claim 5 , wherein one side of the exterior circumferential portion of the insulator is provided with a mounting groove and the other side of the exterior circumferential portion of the insulator is provided with a mounting protrusion. 
     
     
         10 . The method of  claim 9 , wherein the plurality of core-insulator assemblies are connected with each other by inserting the mounting protrusion of one core-insulator assembly in the mounting groove of the other core-insulator assembly. 
     
     
         11 . A electric water pump apparatus, comprising:
 a plurality of core-insulator assemblies to generate a magnetic field according to a control signal, the core-insulator assemblies including a plurality of pieces made of a magnetic material to form a core stack molded by an insulator, wherein the insulator is coiled by a coil to form a core-insulator assembly so as to form a magnetic path, and the respective core-insulator assembly is coupled each other in an annular shape in sequence; and   a rotor enclosed by the stator assembly and rotated by the magnetic field generated by the stator assembly to pressurize coolant.   
     
     
         12 . The electric water pump apparatus of  claim 11 , further comprising a stator case molded to the respective core-insulator assembly and the coil. 
     
     
         13 . The electric water pump apparatus of  claim 12 , wherein the stator case is made of a bulk mold compound including a potassium family that has a low coefficient of contraction. 
     
     
         14 . The electric water pump apparatus of  claim 11 , wherein the pieces respectively have an exterior circumferential portion, an interior circumferential portion, and a connecting portion extending radially in order to connect the exterior circumferential portion to the interior circumferential portion, and
 wherein the insulator has an exterior circumferential portion wrapping the exterior circumferential portion of the pieces, an interior circumferential portion wrapping the interior circumferential portion of the pieces, and a connecting portion wrapping the connecting portion of the pieces and connecting the exterior circumferential portion of the insulator to the interior circumferential portion of the insulator.   
     
     
         15 . The electric water pump apparatus of  claim 14 , wherein circumferential thickness of the connecting portion in the pieces is smaller than those of the exterior circumferential portion and the interior circumferential portion in the pieces. 
     
     
         16 . The electric water pump apparatus of  claim 14 , wherein one side of the interior circumferential portion of the insulator is provided with a mounting groove and the other side of the interior circumferential portion of the insulator is provided with a mounting protrusion. 
     
     
         17 . The electric water pump apparatus of  claim 16 , wherein the plurality of core-insulator assemblies are connected with each other by inserting the mounting protrusion of one core-insulator assembly in the mounting groove of the other core-insulator assembly. 
     
     
         18 . The electric water pump apparatus of  claim 14 , wherein one side of the exterior circumferential portion of the insulator is provided with a mounting groove and the other side of the exterior circumferential portion of the insulator is provided with a mounting protrusion. 
     
     
         19 . The electric water pump apparatus of  claim 18 , wherein the plurality of core-insulator assemblies are connected with each other by inserting the mounting protrusion of one core-insulator assembly in the mounting groove of the other core-insulator assembly.