Coaxial engine starter system

摘要

In a coaxial engine starter comprising a pinion (6) connected to the output shaft (4) which is driven by an electric motor (3), via a helical spline (19), a switch unit (7) for selectively closing a power supply line to the electric motor, and a solenoid device (9) consisting of an annular armature and an annular energization coil surrounding the output shaft to axially drive the pinion and a moveable contact of the switch unit in the axial direction, the switch is adapted to be closed before the pinion is actuated by the solenoid device. Therefore, the output requirement for the solenoid device can be reduced as opposed to the conventional starter in which the pinion is actuated strictly by the solenoid device, and the size of the engine starter can be reduced.