scope:

Automated machines use servomotors to perform complex motions. Planetary gearheads are frequently used in conjunction with servomotors to match the inertias, lower the speed, boost the torque, and at the same time provide a mechanical interface for pulleys, cams, drums and other mechanical components. This paper covers topics such as: reasons why planetary gear systems are chosen for "servo applications"; what influences the planetary servo gear positioning accuracy and repeatability; rating practices to establish a "comparability" of different torques; and, an introduction of a simple method to determine the required gearbox torque rating for a servo-application based on motor torque data.