Starter device

Abstract

An electromagnetic push-out unit which controls engagement and disengagement between a pinion gear and a ring gear for an engine in a starter device via a non-magnetic cylindrical member disposed concentrically with a pinion shaft mechanically coupled to an electrical motor. The electromagnetic push-out unit is concentrically disposed around the cylindrical member and comprises an electromagnetic coil, a stationary core for the electromagnetic coil, a movable core facing to the pole face of the stationary core and forming a magnetic circuit together with the stationary core via a first air gap and a bridge member extending along the moving direction of the movable core, magnetically coupled thereto and facing to the stationary core with a second air gap shorter than the first air gap thereby a part of the magnetic flux in the magnetic circuit bypasses through the bridge member to increase magnetic traction force acting between the stationary core and the movable core at the start of the travel of the movable core and to suppress the increase of the magnetic traction force at the end of the travel thereof.