Gearbox
A gearbox (gear reducer) is an enclosed assembly of gears, shafts and bearings that transmits mechanical power between a prime mover and a driven machine while changing speed and torque. Reducing output speed increases output torque in proportion to the gear ratio, less transmission losses. Common configurations include helical, bevel-helical, worm and planetary designs, arranged with parallel or right-angle shafts. Gearboxes drive conveyors, mixers, cooling tower fans, extruders and cranes. Selection parameters include input power, ratio, output torque, service factor for the duty cycle and shock loads, thermal rating, mounting position, shaft arrangement and lubrication. Gear load capacity is commonly calculated to ISO 6336 or AGMA standards. Worm gearboxes are compact but generally less efficient than helical or planetary units.
Examples
- Helical reducer driving a belt conveyor
- Right-angle gearbox for a cooling tower fan
- Planetary gearbox on a mixer or agitator