Fuel pump, fuel supply equipment using fuel pump and method for manufacturing fuel pump

Abstract

A fuel pump mounted in the fuel tank for the motor cycle comprises a motor and a pump driven by the motor for increasing a pressure of the sucked fuel. The motor is a brushless motor and has a stator core, coils and a rotor. An electrical energization for the coils wound around the stator core is controlled in response to a rotating position of the rotor, thereby the rotor is rotated. The rotor has a shaft, a rotating core and a permanent magnet, and the rotor is rotatably mounted at the inner circumference of the stator core. The permanent magnet is mounted at the outer circumference of the rotating core and magnetically energized so as to form magnetic poles different alternatively in a rotating direction at the outer circumferential surface facing the stator core.

1 . A fuel pump mounted in a fuel tank for a motorcycle comprising: 
 a stator core;    coils wound around the stator core and of which magnetic poles formed in a circumferential direction of the stator core are changed over while the electrical energization is controlled;    a rotor having magnetic poles different to each other alternatively in a rotating direction formed at opposing surfaces facing the stator core; and    a pump having a rotating member rotated with a rotating force of the rotor, the pump increasing a fuel pressure under a rotation of the rotating member.    
   
   
       2 . The fuel pump according to  claim 1 , wherein a displacement of an engine of the motorcycle is equal to or less than 150 cc.  
   
   
       3 . The fuel pump according to  claim 1 , wherein a total amount of driving current fed to the coil is equal to or less than 1 A.  
   
   
       4 . The fuel pump according to  claim 1 , wherein a fuel discharging amount is equal to or more than 5 L/h and less than 30 L/h.  
   
   
       5 . The fuel pump according to  claim 1 , wherein the rotating member has a plurality of vane grooves in a rotating direction, the pump increases a pressure of the fuel in the pump passage formed along the vane grooves under rotation of the rotating member.  
   
   
       6 . The fuel pump according to  claim 5 , wherein an outer diameter of the rotating member is lower than 26 mm.  
   
   
       7 . The fuel pump according to  claim 6 , wherein an outer diameter of the rotating member is equal to or more than 12.1 mm.  
   
   
       8 . The fuel pump according to  claim 1 , 
 wherein the pump has an inner circumferential rotating member provided with a plurality of outer teeth in a rotating direction and an outer circumferential rotating member having inner teeth engaged with the outer teeth and rotatably mounted while being eccentric with respect to the inner circumferential rotating member.    
   
   
       9 . The fuel pump according to  claim 1  wherein the coils are resin molded.  
   
   
       10 . A fuel supply equipment comprising: 
 a fuel pump mounted in a fuel tank including a stator core; coils wound around the stator core and of which magnetic poles formed in a circumferential direction of the stator core are changed over while the electrical energization is controlled; a rotor having magnetic poles different to each other alternatively in a rotating direction formed at opposing surfaces facing the stator core; and a pump having a rotating member rotated with a rotating force of the rotor and for increasing a fuel pressure under a rotation of the rotating member; and    a control device for controlling an electrical energization for the coils, the control device being mounted outside the fuel tank.    
   
   
       11 . The fuel supply equipment according to  claim 10 , wherein the control device controls an electrical energization for the coils in response to an inductive electromotive force generated at the coils stopping the electrical energization.  
   
   
       12 . A fuel supply equipment comprising: 
 a fuel pump mounted in a fuel tank including a stator core; coils wound around the stator core and of which magnetic poles formed in a circumferential direction of the stator core are changed over while the electrical energization is controlled; a rotor having magnetic poles different to each other alternatively in a rotating direction formed at opposing surfaces facing the stator core; and a pump having a rotating member rotated with a rotating force of the rotor and for increasing a fuel pressure under a rotation of the rotating member; and    a control device for controlling an electrical energization for the coils, wherein    the control device controls an electrical energization for the coils in response to an inductive electromotive force generated at the coils stopping the electrical energization.    
   
   
       13 . The fuel supply equipment according to  claim 10 , wherein the control device limits a current value of a current flowing in the coils to a predetermined value or less at the time of starting the motorcycle.  
   
   
       14 . A fuel supply equipment comprising: 
 a fuel pump mounted in a fuel tank including a stator core; coils wound around the stator core and of which magnetic poles formed in a circumferential direction of the stator core are changed over while the electrical energization is controlled; a rotor having magnetic poles different to each other alternatively in a rotating direction formed at opposing surfaces facing the stator core; and a pump having a rotating member rotated with a rotating force of the rotor and for increasing a fuel pressure under a rotation of the rotating member; and    a control device for controlling an electrical energization for the coils, wherein the control device limits a current value of a current flowing in the coils to a predetermined value or less at the time of starting the motorcycle.    
   
   
       15 . The fuel supply equipment according to  claim 13 , wherein the control device has a three-phase circuit for switching an electrical energization for the coils and a limiting circuit for limiting a current value of a current flowing in the coils to a predetermined value or less, wherein the three-phase circuit and the limiting circuit are constituted by one circuit module.  
   
   
       16 . The fuel supply equipment according to  claim 13 , wherein the control device has a three-phase circuit for switching an electrical energization for the coils and a limiting circuit for limiting a current value of a current flowing in the coils to a predetermined value or less, and the three-phase circuit and the limiting circuit are constituted by different circuit modules.  
   
   
       17 . A fuel pump comprising a motor and a pump driven by the motor and for increasing a pressure of fuel, wherein 
 the motor includes: 
 a stator core having coils concentrically wound and having magnetic poles changed over under controlling of an electrical energization for the coils; and  
 a rotor having magnetic poles different to each other alternatively in a rotating direction formed at opposing surfaces facing the stator core, rotated through changing-over of the magnetic poles formed in a circumferential direction of the stator core so as to drive the pump; and  
   a passage where fuel flows from the pump is formed between the stator core and the rotor.    
   
   
       18 . The fuel pump according to  claim 17 , wherein 
 the rotor is mounted at the inner circumference of the stator core;    the stator core includes an outer circumference and a plurality of teeth protruded from the outer circumference toward the rotor at the inner circumference and having the coils concentrically wound; and    the outer circumference is connected to at least one outer circumferential end of the tooth, and bent toward the inner circumference at the outer circumferential end of the teeth.    
   
   
       19 . The fuel pump according to  claim 18 , wherein 
 the outer circumference is formed into a discontinuous annular shape at one location in a circumferential direction, and the outer circumference and the plurality of teeth are constituted by one member.    
   
   
       20 . The fuel pump according to  claim 18 , wherein 
 the outer circumference comprises arcuate portions connected with the outer circumferential end of the teeth and bent toward the inner circumference at the outer circumferential end and the arcuate portions are formed in a substantial equal width in a circumferential direction.    
   
   
       21 . The fuel pump according to  claim 17 , wherein 
 the rotor is mounted at the inner circumference of the stator core;    the stator core includes an outer circumferential core and a plurality of coil cores protruded toward the rotor at the inner circumference from the outer circumferential core and having the coils concentrically wound; and    the plurality of coil cores are members separate from the outer circumferential core.    
   
   
       22 . The fuel pump according to  claim 18 , further comprising a housing for press fitting the stator core.  
   
   
       23 . The fuel pump according to  claim 17 , wherein an insulator is provided between the stator core and the coil.  
   
   
       24 . The fuel pump according to  claim 23 , wherein the insulator is fitted to the stator core.  
   
   
       25 . A method for manufacturing the fuel pump according to  claim 18  comprising the steps of: 
 winding windings concentrically around the teeth to form the coils under a state before the outer circumference at the outer circumferential end of the teeth is bent in a direction approaching to the teeth; and    bending the outer circumference at the outer circumferential end at the teeth in a direction approaching to the teeth after the winding step.    
   
   
       26 . The method for manufacturing the fuel pump according to  claim 25 , wherein the outer circumference under a state before winding the windings around the teeth is spaced apart from the teeth rather than an imaginary straight line crossing at a right angle with the teeth at the outer circumferential end.  
   
   
       27 . A fuel supply equipment fixed to a bottom wall of a fuel tank for feeding fuel in the fuel tank out of the fuel tank, comprising: 
 a lid member covering an opening formed at the bottom wall of the fuel tank, and a fuel pump supported at the lid member and mounted at the bottom part in the fuel tank,    wherein an electrical driving part for the fuel pump is a brushless motor, and the fuel pump is mounted in a lateral orientation within the fuel tank along the lid member.    
   
   
       28 . The fuel supply equipment according to  claim 27 , wherein the brushless motor includes a stator core, coils wound around the 
 stator core and having magnetic poles formed in a circumferential direction of the stator core through controlling of electrical energization and changed over, and a rotor forming the magnetic poles different to each other alternatively in a rotating direction at the opposing surfaces facing the stator core.    
   
   
       29 . The fuel supply equipment according to  claim 27 , wherein a terminal is provided which is electrically connected to an electrical device including the fuel pump mounted in the fuel tank and mounted above the fuel tank while being spaced from the lid member.  
   
   
       30 . The fuel supply equipment according to  claim 29 , wherein the terminal is mounted above the fuel tank rather than the end part of the fuel pump at the bottom side of the fuel tank.  
   
   
       31 . The fuel supply equipment according to  claim 27 , wherein a suction filter is further provided which is connected to a suction port of the fuel pump for removing a foreign material in the fuel sucked by the fuel pump, the suction filter is directed in substantially the same direction as that where the fuel pump is placed in a lateral orientation, and extends toward an outside of the lid member.  
   
   
       32 . The fuel supply equipment according to  claim 27 , which is fixed to the bottom wall of a fuel tank for a motorcycle.