When it comes to gearing components, things can get confusing quickly. There are many terms that gear manufacturers as well as engineers and designers use to talk about what sometimes is essentially the same thing. And the term “gearbox” is one of those terms, often times used interchangeably with gearhead or gear reducer, even though they may in fact refer to slightly different physical arrangements of gears.
The most basic definition of a gearbox is that it is a contained gear train, or a mechanical unit or component consisting of a series of integrated gears within a housing. In fact, the name itself defines what it is; a box containing gears. In the most basic sense, a gearbox functions like any system of gears; it alters torque and speed between a driving device like a motor and a load.
The gears inside of a gearbox can be any one of a number of types from bevel gears and spiral bevel gears to wormgears and others such as planetary gears. The gears are mounted on shafts, which are supported by and rotate via rolling element bearings. The gearbox is a mechanical method of transferring energy from one device to another and is used to increase torque while reducing speed.
Gearboxes are used in many applications including machine tools, industrial equipment, conveyors, and really any rotary motion power transmission application that requires changes to torque and speed requirements.
More detailed information on gearboxes, including how to select them, and gears in general can be found at the links below: