Fuel pump to be installed inside fuel tank

A fuel pump for supplying fuel drawn from a fuel tank into an internal combustion engine, the fuel pump comprising:

• a housing;
• a rotor provided in the housing;
• a rotation shaft, which revolves integrally with the rotor;
• shaft bearing members, which support both axial ends of the rotation shaft;
• a stator, which is disposed in the housing to surround an outer circumference of the rotor;
• and
• a drawing force generative means, which generates drawing force for drawing fuel from the fuel tank by means of rotation force of the rotor to supply the fuel through the housing in an axial direction of the rotor, wherein the rotor and the drawing force generative means are disposed to be overlapped in the axial direction of the rotor, wherein:
• the rotor and the drawing force generative means respectively have stepped portions;
• the rotor and the drawing force generative means are disposed to be overlapped in the axial direction of the rotor so that the stepped portions oppose each other;
• the stator has a permanent magnet, which is disposed on its circumference and forms a plurality of magnetic poles the polar characters of which are alternated;
• the rotor includes an armature, which is rotatably disposed inside of the stator, and a commutator, which rotates integrally with the armature and has a plurality of segments respectively electrically connected with coils of the armature;
• the armature has a cover, which covers one of the axial end portions of the armature, and said stepped portion of the rotor includes a stepped portion formed in said cover, and
• the cover is rotatable with the coils of the armature and faces the drawing force generative means.

An apparatus for supplying fuel drawn from a fuel tank, the apparatus comprising:

• a rotor including armature coils;
• a rotation shaft, which revolves integrally with the rotor;
• bearing members, which support both axial ends of the rotation shaft;
• a stator disposed around an outer circumference of the rotor;
• a drawing force generative means, which is disposed adjacent to the rotor in an axial direction of the rotation shaft and generates drawing force for drawing fuel from the fuel tank by means of rotation force of the rotor and supplying the fuel into a space between the rotor and the stator in the axial direction, wherein:
• the rotor has a recess in a center of one axial end portion thereof, which faces the drawing force generative means;
• at least one of the bearing members is disposed in the recess to overlap with the rotor in the axial direction;
• and
• a cover provided over a surface of the one axial end portion of the rotor thereby to smooth flow of the fuel supplied through the drawing force generative means, the cover being rotatable with the rotor.

An apparatus for supplying fuel drawn from a fuel tank into an internal combustion engine, the apparatus comprising:

• a housing;
• a rotor provided in the housing and having a recess in a radial center portion of an axial end portion thereof;
• a rotation shaft passing through the radial center portion of the rotor and rotatable with the rotor;
• a stator disposed in the housing to surround an outer circumference of the rotor;
• a pump cover having a fuel inlet port;
• a pump casing attached to the pump casing and positioned between the pump cover and the rotor, the pump casing having a fuel outlet port from which fuel is discharged into the housing;
• and
• an impeller disposed between the pump cover and the pump casing and fixed to the rotation shaft to be rotated by the rotation shaft, wherein:
• the pump casing rotatably supports the rotation shaft therein,
• the pump casing is disposed to extend into the recess of the pump casing in an axial direction of the rotation shaft,
• the pump casing has a radial center portion, which rotatably supports the rotation shaft and projects into the recess to overlap with the rotor in the axial direction of the rotation shaft,
• the pump cover and the pump casing are provided in the housing with the stator and the rotor, and the pump cover closes one axial end of the housing,
• the rotor has a core fixed to the rotation shaft and coils extending from the core in the axial direction of the rotation shaft to form the recess in a radially inside part thereof, and
• the rotor has a cover, which covers an axial end face of the coils to smooth the axial end face of the coils and promotes smooth flow of fuel into a space between the rotor and the stator.