Why do older AC door motors require a speed reduction unit?

Older AC door motors require a speed reduction unit primarily because they often operate at high RPMs (revolutions per minute). The design of these motors typically results in a faster rotational speed than what is practical for door operation. A speed reduction unit effectively decreases the rotational speed transmitted to the door operating mechanism, allowing for smoother door movement and better control. It ensures that the door opens and closes at a safe and manageable speed, which is essential for both passenger safety and mechanical reliability.

While increasing torque, improving efficiency, or easing installation might be relevant concerns for different types of motors or applications, the specific need for a speed reduction unit in older AC door motors is directly tied to managing the high RPM output to achieve optimal door operation.