Abstract:
A starter for an internal combustion engine includes a motor, a pinion gear connected to the motor to be engaged with a ring gear of the engine. The pinion gear has teeth of a negative addendum modification whose number is larger than a standard gear that has the same outside diameter. Therefore the gear ratio of the pinion gear to the ring gear can be increased without change of the outside diameter thereof.
Abstract:
In a starter, an output shaft is disposed on a same axial line with a motor shaft through a planetary gear reduction device. The output shaft has an accommodation recess at the rear end thereof and rotatably receives the top end of the motor shaft therein through a ball. The output shaft and the motor shaft have respective end surfaces opposing each other in the axial direction with a spacing therebetween under a condition that the ball is disposed between the output shaft and the motor shaft. A thrust receiving member thinner than the spacing is disposed in the spacing. The thrust receiving member limits a movement of the output shaft toward the motor due to wear of the accommodation recess.