With the many commercial gearboxes on the market, it’s vital that you 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 critical for accurate and repeatable movement. Planetary gearboxes fit the bill for servo applications.
High-precision helical planetary gearboxes are an excellent choice for applications that need precision and reliability. Planetary gearboxes 
have very low backlash servo motor gear reducers ratings (typically ranging from someone to nine arc-min), and when sized correctly provide a service life of over 20,000 hours with virtually no maintenance. Helical planetary gears also provide very silent and better operation in comparison with competitive products.
Precision gearboxes are carefully machined to high tolerances – think clockmaker, not blacksmith. They provide power densities that translates to small bundle size and efficiencies of 90% and greater.
Servomotors often drive loads directly without the need for a gearbox, however in many applications it’s beneficial to make use of a gearbox between your motor and load.
One main reason to use a gearbox is torque multiplication. It lets designers use smaller sized servosystems that consumes much less energy. Rather than buying relatively huge servodrives and motors, developer can use smaller elements, saving space and money.
Output torque increases in direct proportion to the apparatus ratio, and top speed of the output shaft decreases. If an application can withstand the decreased speed, a relatively small servosystem can supply high torque.
Gearboxes can also address inertia mismatches. For high performance servosystems — those with high dynamic responses or low overshoot, for instance – the ratio between the reflected load inertia and engine inertia should be only practical, preferably under ten-to-one. A precision gearbox decreases the reflected inertia by the square of the decrease ratio. For instance, using a 25:1 gearbox decreases the load’s reflected inertia by one factor of 625, a substantial improvement.