What are the two categories that starter motors fall into?

Starter motors primarily fall into two categories: direct drive and gear reduction.

Direct drive starter motors function by connecting directly to the engine's flywheel, allowing for a straightforward engagement and disengagement process. This type typically generates high torque at low speeds, making it effective for turning over the engine during start-up.

On the other hand, gear reduction starter motors utilize a gear system to increase the torque output. They work by allowing a smaller motor to drive a larger gear, enhancing the torque while minimizing the motor's size and weight. This is particularly advantageous in situations where space is limited or when a more powerful start is needed without adding excessive size to the starter motor.

Understanding these two categories is crucial, as they reflect the different designs and applications of starter motors in various engines, impacting efficiency and performance during engine start-up.