Gearbox or Speed Reducer?

When looking at speed reducer vs. gearbox often the only difference is terminology. This is because all speed reducers are gearboxes. However, not all gearboxes are speed reducers. This might sound a bit complicated, but it’s actually pretty straight forward.

Speed reducers are gear trains between a motor and a piece of machinery. The purpose of the speed reducer is to reduce the rpm that is transmitted between these two end points. Speed reducers take the torque created by the motor (the input) and multiply it. Second, speed reducers, much as the name implies, reduce the speed (the rpm output) of the input so that the output is the correct speed.

The term “gearbox” is simply a generic term for a gear train between a motor and a piece of machinery. Hence, all speed reducers are gearboxes.

However, not all gearboxes reduce the speed of the input. While not common, gearboxes can actually be tooled to increase the speed of the input. By far the most common type of gearboxes are speed reducers, but it wouldn’t be correct to say all gearboxes are speed reducers.