Starting motor device

Abstract

A compact starting motor device for an engine of improved durability capable of ensuring a smooth and quick engagement of a pinion gear, operatively connected to an electric motor, with a driven gear of the engine upon actuation of an electromagnetic device without generating any substantial shock. The motor is connected through a one-way clutch to an output shaft so that a driving force is transmitted unidirectionally from the motor to the output shaft. The pinion gear is splined to a projecting end of the output shaft for relative axial movement and axially moved thereon to engage and disengage the driven gear by means of a rod which extends coaxially within the output shaft. The rod is connected through an over-load spring to the electromagnetic device having a stationary core and a movable core. A switch for energizing the electric motor is provided on the movable core. Upon actuation of the electromagnetic device, the movable core is magnetically drawn to the stationary core to axially move the pinion gear via the rod to engage the engine driven gear. At this time, if the teeth of the pinion gear are not in alignment with those of the driven gear, the movable core is further moved under magnetic attraction toward the stationary core with deformation of the over-load spring to turn on the switch to energize the electric motor whereby the pinion gear is rotated to align its teeth with those of the driven gear for complete meshing engagement therebetween.