Starting motor components: which statement is most accurate?

Starting motor components: which statement is most accurate?

• A. Gear reduction occurs between the pinion and the flywheel.
• B. An overrunning clutch freewheels to prevent damage to the starter.
• C. Both statements are true.
• D. Neither statement is true.

Answer: (C)

When a starter is activated, it must deliver enough torque at low speed to overcome engine compression. That’s achieved by gear reduction in the path from the starter armature to the flywheel. The pinion gear on the starter meshes with the flywheel’s ring gear; because the ring gear is much larger, the motion is slowed and torque is increased at the flywheel, giving the engine a strong initial turn. The drive assembly also uses an overrunning clutch, known as a Bendix drive, which pushes the pinion into engagement when the starter is energized and then automatically freewheels once the engine speed overtakes the starter. This prevents the engine from trying to drive the starter gear, protecting the starter from damage. So both statements describe real features of starting motor design.

When a starter is activated, it must deliver enough torque at low speed to overcome engine compression. That’s achieved by gear reduction in the path from the starter armature to the flywheel. The pinion gear on the starter meshes with the flywheel’s ring gear; because the ring gear is much larger, the motion is slowed and torque is increased at the flywheel, giving the engine a strong initial turn. The drive assembly also uses an overrunning clutch, known as a Bendix drive, which pushes the pinion into engagement when the starter is energized and then automatically freewheels once the engine speed overtakes the starter. This prevents the engine from trying to drive the starter gear, protecting the starter from damage. So both statements describe real features of starting motor design.