Patent attributes
A fuel supply device has a cover member which is attached to an opening of a fuel tank, a pump unit comprising a pump, and a connecting portion configured to connect the cover member and the pump unit. A connecting shaft which is formed to one of the two connected members of the connecting portion is inserted into a connecting hole which is formed to the other of the two such that the pump unit is connected to be relatively movable to the connecting portion. The pump unit includes an upper base on which the pump is placed, and a lower base which contacts to the fuel tank. The upper base and the lower base are coupled through attachments whereby an engagement portion of the upper base is fitted into a recessed portion formed on the side of the lower base. The recessed portion has a pair of planes opposing to each other and oriented toward a bottom surface of the lower base from a predetermined position. The recessed portion is further configured such that an interval between a pair of the planes is gradually increased toward the bottom surface.