Why are reduction gears necessary?

Most electric motors have a fixed range of speed and torque, which corresponds to their most efficient operating conditions. However, the tasks that need to be performed often require speeds significantly lower and torques substantially higher than what the motor can deliver efficiently.

In other words, the motor operates at high speed with low torque, whereas the task requires low speed and high torque. If the task is performed solely by the motor, it must run outside its optimal efficiency range; unless a larger, more expensive motor is used, this will lead to overheating, reduced service life, and other adverse effects.

At this point, a reduction gear can be used to lower the motor’s output speed and increase torque. By selecting an appropriate gear ratio, the motor can operate within its high‑efficiency range, thereby achieving the desired speed and torque at the output shaft.

Reduction gears are used in many applications.

When precise control of motion is required, reduction gears are used. They are ubiquitous in numerous applications around us. Here are some key examples:

・Elevators, escalators, and other moving devices

・Conveyor belts, industrial robots, and other factory equipment

・Automated devices such as automatic doors and automatic blinds

・Precision devices such as medical, measurement, and optical instruments

The application scope of gear reducers is extremely broad; from everyday devices such as automatic doors and elevators to industrial robots operating within factories, gear reducers are indispensable components in all these systems.

Benefits of Using a Reduction Gear

Mechanical transmission gear

Concept of mechanical watch repair. Close-up of mechanical watch components.

This section briefly analyzes the benefits of using a reducer.

High torque, compact size

A straightforward way to increase torque is to use a larger motor. However, in many applications, available space for motor installation is limited—especially when the motor is mounted inside machinery, robots, or other equipment. Torque can also be boosted by increasing the electrical input. Yet if more power is supplied, the motor may overheat, leading to reduced efficiency and eventual failure.

A gearbox can be used to generate several hundred times the torque from a single motor. This means that greater torque can be achieved with a motor of the same size, or that a smaller motor can be employed to meet existing torque requirements. Furthermore, by using appropriately sized power, motor overheating can be prevented, ensuring safe and reliable operation.