Patent ID: 7621723

Claim:
An electromagnetic pump where a plunger including a magnetic body is provided so as to be capable of sliding inside a cylinder that is sealed at both end surfaces thereof by a pair of frames with spaces between the plunger and the end surfaces of the respective frames as pump chambers, air-core electromagnetic coils are disposed around an outer circumference of the cylinder, and a fluid is conveyed by passing a current through the electromagnetic coils to reciprocally move the plunger in an axial direction of the cylinder, wherein intake valves and outflow valves that connect the pump chambers and the outside are provided inside regions of the frames at the end surfaces of the cylinder, wherein the plunger is formed by sandwiching a magnet that is formed into a circular disk-like shape and magnetized in the thickness direction between a pair of inner yokes, and wherein flange portions that are shaped as short tubes and are in sliding contact with an inner surface of the cylinder at positions facing the electromagnetic coils are provided on edge portions of plate-like portions of the inner yokes that sandwich the magnet.