A gearbox is a mechanical device that transmits rotational motion and torque from one shaft to another. Its primary function is to adjust the speed and torque of the drive system to meet the operational requirements of the application. Depending on the gear ratio, a gearbox can reduce speed to increase torque, or increase speed while reducing torque.
Common types of gearbox include spur, planetary and bevel gearboxes, as well as manual and power shift transmissions Transmission The function of a vehicle transmission is to adjust the torque and speed, and to transfer engine power to the drive wheels. . Gear transmission Transmission The function of a vehicle transmission is to adjust the torque and speed, and to transfer engine power to the drive wheels. typically occurs through the meshing of gear teeth, though it can also involve belts, chains, or shafts. Gearboxes are used in many different industries, including automotive, aerospace, marine, energy, manufacturing and robotics.
Design considerations for gearboxes include torque capacity, space constraints, desired gear ratios, efficiency, thermal behaviour and durability.