With the many commercial gearboxes on the market, it's important to match the proper type of gearbox with 
the drive, motor, and load. Whenever a machine requires a servosystem (drive and engine), the gearbox type is crucial for accurate and repeatable motion. Planetary gearboxes fit the bill for servo applications.
High-precision helical planetary gearboxes are an excellent choice for applications that require accuracy and reliability. Planetary gearboxes possess very low backlash ratings (typically ranging from someone to nine arc-min), and when sized correctly provide a service lifestyle of over 20,000 hours with virtually no maintenance. Helical planetary gears provide very silent and more efficient operation as compared to competitive products.
Precision gearboxes are carefully machined to high tolerances – believe clockmaker, not blacksmith. They offer power densities that translates to small package size and efficiencies of 90% and greater.
Servomotors often drive loads directly without the need for a gearbox, but in many applications it's advantageous to use a gearbox between the motor and load.
One main reason to employ a gearbox is torque multiplication. It lets designers use smaller servosystems that consumes less energy. Rather than buying relatively large servodrives and motors, designer can use smaller components, saving space and cash.
Output torque improves in direct proportion to the gear ratio, and top rate of the result shaft decreases. If an application can withstand the reduced speed, a relatively small servosystem can supply high torque.
Gearboxes can also address inertia mismatches. For powerful servosystems — people that have high powerful responses or low overshoot, for instance – the ratio between the reflected load inertia and electric motor inertia should be only practical, ideally under ten-to-one. A precision gearbox servo motor gear reducers decreases the reflected inertia by the square of the reduction ratio. For instance, using a 25:1 gearbox reduces the load's reflected inertia by one factor of 625, a substantial improvement.