Abstract: A motor type fuel pump includes an armature housing made of a substantially cylindrical plastic member whose upper end is closed, and a pump chamber housing accommodating a impeller rotated by the armature and defining a pump chamber. The armature housing is adapted to accommodate motor components including an armature, a commutator, a cylindrical stator device consisting of a permanent magnet and a yoke. The armature housing has a plurality of ribs formed at predetermined angular intervals on an inner surface of the armature housing and extending along the longitudinal direction of the armature housing. The plurality of ribs are fitted on the yoke of the stator device. Fuel is supplied through a plurality of arcuated grooves which are defined by the outer surface of the yoke, the inner wall surface of the armature housing, and the ribs.

Abstract: In an electromagnetic pump, the inner end of an outlet pipe fixed in a pump housing extends for a predetermined length inside a sleeve housing a plunger to form a pump delivery pulsation absorption chamber around the outlet pipe. The inner end opening of this pipe is selectively closed by a control valve serving as a guide member for slidably guiding a valve body of a delivery valve along the axial direction. The fuel leakage prevention control valve and the pulsation absorption chamber are simply and optimally formed with a single construction.

Abstract: An electromagnetic pump has a pump housing. The pump housing consists of a cup-like housing body with an outlet cylindrical portion at the center thereof and a lid member having an inlet cylindrical portion at the center thereof. The lid member is fixed to the cup-like housing body. The pump also includes a nonmagnetic sleeve member, a magnetic plunger slidably fitted in the nonmagnetic sleeve member, a return spring for biasing the plunger to a delivery side, inlet and outlet pipes, a coil bobbin arranged around the sleeve member, a transistor assembly consisting of a transistor and a heat sink, a printed circuit board, a holder mounted above the printed circuit board, a leaf spring arranged between the housing body and the holder. A plurality of studs extend on the outer side surface of the flange of the coil bobbin on which the transistor assembly is mounted and on an inner side surface of the holder.