Abstract: In a starter motor equipped with a shock absorbing device, a disk spring is placed between a bottom part of a cylindrical casing and one side of a disk stack structure composed of rotatable disks and fixed disks which are alternately stacked. Caulking parts formed at an opening end of the cylindrical casing are bent toward the inner diameter side of the cylindrical casing in order to push the disk spring toward the bottom part side of the cylindrical casing through the disk stack structure. The disk spring accumulates reaction force (or elastic force) by the caulking. The reaction force accumulated in the disk spring pushes the disk stack structure to the axial direction of the cylindrical casing. The structure of the shock absorbing device can supply a uniform load to the disk spring, and provides a stable shock absorbing capability.

Abstract: A starter for cranking an internal combustion engine includes an electric motor, an output shaft, a pinion gear coupled to the output shaft. The starter motor further includes one-way clutch for transmitting the rotational torque of the electric motor to the output shaft while interrupting transmission of the rotational torque from the pinion gear driven by the engine to the electric motor. A clutch-inner of the one-way clutch is integrally formed with the output shaft. When the output shaft is driven by the engine via the pinion gear, a swinging rotation may be caused due to a small inclination of the output shaft relative to a real center axis of the starter. To suppress the swinging rotation, a washer is connected to a front end of the one-way clutch, and the washer is adapted to contact a rear end of the sliding bearing supporting the output shaft when the output shaft is rotated by the engine.

Abstract: In a starter motor equipped with a shock absorbing device, a disk spring is placed between a bottom part of a cylindrical casing and one side of a disk stack structure composed of rotatable disks and fixed disks which are alternately stacked. Caulking parts formed at an opening end of the cylindrical casing are bent toward the inner diameter side of the cylindrical casing in order to push the disk spring toward the bottom part side of the cylindrical casing through the disk stack structure. The disk spring accumulates reaction force (or elastic force) by the caulking. The reaction force accumulated in the disk spring pushes the disk stack structure to the axial direction of the cylindrical casing. The structure of the shock absorbing device can supply a uniform load to the disk spring, and provides a stable shock absorbing capability.

Abstract: The clutch outer 24 is formed in the planet carrier 24 that outputs the orbital motion of the planetary gear 23, and the outer regulating part 33 is formed in the central part of the planet carrier 24. In the outer regulating part 33, he round hole 33a is formed in the central part of the direction of the diameter. The anti-motor side of the armature shaft 2 is inserted through the round hole 33a. The end part of the armature shaft 2 is inserted into the inside of the concave section 26b that passes through the round hole 33a provided on the outer regulating part 33. The armature shaft bearing 34 that is press fit in the inner circumference of the concave section 26b supports the armature shaft 2 relatively rotatable. Consequently, the deflection of the armature shaft 2 can be controlled, and the deflection of the clutch outer 24 can be controlled in the range of the smooth torque transfer of the one-way clutch 7.