Fuel pump

Abstract

A fuel pump 10 may be with a substantially disk-shaped impeller 20 and a casing 14 for housing the impeller 20 such that the impeller 20 can rotate. Permanent magnets 26 may be disposed in the impeller 20. A driving coil 40 may be disposed in the casing 14 at a location opposite the permanent magnets 26. The impeller 20 rotates when power is supplied to the driving coil 40. The fuel pump 10 may include a supporting device 42 for supporting the impeller. The supporting device 42 may be located in at least one location in an inner face of the casing 14, this inner face of the casing being located opposite an upper face, a lower face, and an outer peripheral face of the impeller 20. It is preferred that the supporting device 42 has a rolling element that makes rolling contact with the impeller 20.

1 . A fuel pump comprising: 
 a substantially disk-shaped impeller having permanent magnets disposed therein,    a casing for housing the impeller such that the impeller can rotate, the casing having a driving coil disposed at a location opposite the permanent magnets of the impeller, and wherein the driving coil causes the impeller to rotate when power is supplied to the driving coil, and    a supporting device supporting the impeller and being disposed in at least one location in an inner face of the casing, this inner face of the casing being located opposite an upper face, a lower face, and an outer peripheral face of the impeller, and wherein the supporting device has a rolling element, this rolling element making rolling contact with the impeller.    
   
   
       2 . The fuel pump as in  claim 1 , wherein: 
 a first group of concavities is formed in an upper face of the impeller along a region in the vicinity of an outer periphery of the impeller, and the first group of concavities is formed outwards with respect to the permanent magnets,    a second group of concavities is formed in a lower face of the impeller along a region in the vicinity of an outer periphery of the impeller, and the second group of concavities is formed outwards with respect to the permanent magnets,    a first groove is formed in the inner face of the casing opposite the upper face of the impeller, this first groove being formed in a region opposite the first group of concavities in the impeller and extending from an upstream end to a downstream end,    a second groove is formed in the inner face of casing opposite the lower face of the impeller, this second groove being formed in a region opposite the second group of concavities in the impeller and extending from an upstream end to a downstream end, and    a fuel intake passage and a fuel discharge passage are formed in the casing, wherein the fuel intake passage communicates between the vicinity of the upstream end of the first groove and the exterior of the casing, and between the vicinity of the upstream end of the second groove and the exterior of the casing, and wherein the fuel discharge passage communicates between the vicinity of the downstream end of the first groove and the exterior of the casing, and between the vicinity of the downstream end of the second groove and the exterior of the casing.    
   
   
       3 . The fuel pump as in  claim 2 , wherein: 
 the supporting device is disposed in the inner face of the casing opposite both the upper and the lower face of the impeller, and    the supporting device supports the impeller at a region outwards with respect to the region having the permanent magnets, and inwards with respect to the region having the concavities formed therein.    
   
   
       4 . The fuel pump as in  claim 1 , wherein the supporting device is disposed in at least three locations in the inner face of the casing opposite the outer peripheral face of the impeller.  
   
   
       5 . The fuel pump as in  claim 4 , wherein the rolling element of the supporting device is a tapered roller, and a small diameter side of the tapered roller is located at an upper face side of the impeller, and a large diameter side of the tapered roller is located at a lower face side of the impeller.  
   
   
       6 . The fuel pump as in  claim 1 , the fuel pump further comprising: 
 a shaft attached to the impeller and having both end faces formed in a cone shape,    a shaft receiving member formed at each end of the shaft, each shaft receiving member having a shaft receiving face located opposite each end face of the shaft, and wherein a groove conforming with the cone shape is formed in each shaft receiving face, and an end part of the shaft is supported in the groove of the shaft receiving face.    
   
   
       7 . The fuel pump as in  claim 1 , the fuel pump further comprising: 
 a ball shaft attached to the impeller, and    a shaft receiving member formed at each of the upper face and the lower face of the impeller, this shaft receiving member supporting the ball shaft.    
   
   
       8 . A fuel pump comprising 
 a substantially disk-shaped impeller having permanent magnets disposed therein,    a casing for housing the impeller such that the impeller can rotate, the casing having a driving coil disposed at a location opposite the permanent magnets of the impeller, wherein the driving coil causes the impeller to rotate when power is supplied to the driving coil,    a shaft attached to the impeller and having both end faces formed in a cone shape, and    a shaft receiving member formed at each end of the shaft, the shaft receiving member having a shaft receiving face located opposite each end face of the rotary shaft, and wherein a groove conforming with the cone shape of the shaft is formed in each shaft receiving face, and an end part of the shaft is supported in the groove of the shaft receiving face.    
   
   
       9 . A fuel pump comprising: 
 a substantially disk-shaped impeller having permanent magnets disposed therein,    a casing for housing the impeller such that the impeller can rotate, the casing having a driving coil disposed at a location opposite the permanent magnets of the impeller, wherein the driving coil causes the impeller to rotate when power is supplied to the driving coil,    a ball shaft attached to the impeller, and    a shaft receiving member formed at each of an upper face and a lower face of the impeller, this shaft receiving member supporting the ball shaft.