The APEX servo gearbox has been designed for direct attachment to popular servomotors. The power is transmitted from the motor to sun gear. The sun gear drives three planet gears, which are contained within an internal toothed ring gear. The planet gears are mounted on the planet carrier with double wall supports. The planet carrier is part output shaft. So when the sun gear rotates, it drives the three planet gears inside the ring gear. As planet gears rotate with carries and automatically the output shaft rotates.

Due to the load sharing into multiple tooth contacts, the planetary gearbox provides the highest torque and stiffness for a given envelope. The other significant advantages are simple and efficient lubrication and a balanced system at high speeds. The balanced planetary kinematics and the associated load sharing makes the planetary-type gearbox truly ideal for servo applications.