Brushless motor and fluid pump having the same

Abstract

A fuel pump includes a stator core that has teeth being circumferentially arranged. Coils are formed by concentrically winding a wire around each of the teeth. The coils circumferentially generate magnetic poles in inner circumferential peripheries of the teeth when being supplied with electricity. The magnetic poles being switched by controlling electricity supplied to the plurality of coils. A rotator has an outer circumferential periphery opposed to the inner circumferential peripheries. The outer circumferential periphery defines magnetic poles different from each other with respect to a rotative direction thereof. A pump portion that has a rotor member rotated by the rotator for pumping fuel. An electrically insulative resin material is charged between the teeth, which are circumferentially adjacent to each other, thereby being molded such that the electrically insulative resin material covers the plurality of coils.

1 . A fluid pump comprising: 
 a stator core that includes a plurality of teeth, which is circumferentially arranged;    a plurality of coils each being formed by concentrically winding a wire around an outer circumferential periphery of each of the plurality of teeth, the plurality of coils circumferentially generating magnetic poles in inner circumferential peripheries of the plurality of teeth when being supplied with electricity, the magnetic poles being switched by controlling electricity supplied to the plurality of coils;    a rotator that is rotatable around the inner circumferential peripheries of the plurality of teeth, the rotator having an outer circumferential periphery opposed to the inner circumferential peripheries of the plurality of teeth, the outer circumferential periphery defining magnetic poles different from each other with respect to a rotative direction of the rotator;    a pump portion that has a rotor member, the rotator rotating the rotor member for pumping fluid; and    an electrically insulative resin material that is charged between the plurality of teeth, which are circumferentially adjacent to each other, wherein the electrically insulative resin material is molded such that the electrically insulative resin material covers the plurality of coils.    
   
   
       2 . The fluid pump according to  claim 1 , wherein the plurality of teeth is separate from each other.  
   
   
       3 . The fluid pump according to  claim 1 , wherein the electrically insulative resin material is integrally molded with a cover that covers an end of the stator core on an opposite side of the pump portion with respect to the stator core.  
   
   
       4 . The fluid pump according to  claim 3 , further comprising: 
 a valve member that restricts fluid, which is pumped using the pump portion, from causing reverse flow; and    a stopper that restricts a lift position of the valve member,    wherein the cover accommodates the valve member and the stopper.    
   
   
       5 . The fluid pump according to  claim 1 , further comprising: 
 a plurality of terminals that is insert-molded in the electrically insulative resin material, the plurality of terminals electrically connecting with the plurality of coils; and    a slant restricting member that restricts the plurality of terminals from being slanted when the electrically insulative resin material is molded.    
   
   
       6 . The fluid pump according to  claim 1 , 
 wherein the stator core includes a toroidal core that circumferentially surrounds outer circumferential peripheries of the plurality of teeth, and    each of the plurality of teeth engages with the toroidal core.    
   
   
       7 . A brushless motor that is at least partially submerged in fluid, the brushless motor comprising: 
 a stator core that includes a plurality of teeth, which is circumferentially arranged;    a plurality of coils each being formed by concentrically winding a wire around an outer circumferential periphery of each of the plurality of teeth, the plurality of coils circumferentially generating magnetic poles in inner circumferential peripheries of the plurality of teeth when being supplied with electricity, the magnetic poles being switched by controlling electricity supplied to the plurality of coils;    a rotator that is rotatable around the inner circumferential peripheries of the plurality of teeth, the rotator having an outer circumferential periphery opposed to the inner circumferential peripheries of the plurality of teeth, the outer circumferential periphery defining magnetic poles different from each other with respect to a rotative direction of the rotator; and    an electrically insulative resin material that is charged between the plurality of teeth, which are circumferentially adjacent to each other,    wherein the electrically insulative resin material is molded such that the electrically insulative resin material covers the plurality of coils, and    the electrically insulative resin material insulates the plurality of coils from the fluid.