Patent ID: 7950898
Filing Date: 2011-05-31
Classification: F04D

Abstract:
1. A fuel pump comprising: an impeller rotatable for pumping fuel; a housing including an internally-large cylindrical portion and an internally-small cylindrical portion being coaxially connected with each other, the internally-small cylindrical portion having a small inner diameter less than a large inner diameter of the internally-large cylindrical portion; a casing including a press-inserted portion press-inserted to an inner periphery of the internally-small cylindrical portion, the casing further including an accommodating cylindrical portion located in the internally-large cylindrical portion to be opposed to an outer circumferential periphery of the impeller, the casing further including an accommodating disc portion being opposed to a bottom surface of the impeller on a side of the press-inserted portion; and a cover being in contact with an end surface of the accommodating cylindrical portion on an opposite side of the accommodating disc portion to surround the impeller on the opposite side of the accommodating disc portion, wherein the accommodating disc portion has an impeller-side surface on a side of the impeller, the impeller-side surface and an inner periphery of the accommodating cylindrical portion defining an accommodating corner therebetween, the press-inserted portion has an outer circumferential periphery having an axial end defining a press-inserted corner on a side of the accommodating cylindrical portion, the accommodating corner is distant from the press-inserted corner by a first distance (L the outer circumferential periphery of the press-inserted portion has an axially center portion being distant from the impeller-side surface of the accommodating disc portion by a second distance (L the accommodating corner is recessed outward in a radial direction beyond the inner periphery of the accommodating cylindrical portion, the outer circumferential periphery of the impeller is located on a radially outside of a vane groove of the impeller and a C-shaped groove of the cover, and a concave deformation allowable value of the accommodating disc portion is less than a convex deformation allowable value of the accommodating disc portion.