An Antibacklash Method for Wolfrom Reducers

Abstract

Space rotary actuators are essential components in spacecraft systems that control the orientation and position of the mechanisms. In these actuators, the gear reducers reduce the speed of the motors, increase their resolution and multiply their torque. In applications where the accuracy and repeatability are critical, an antibacklash system is required to eliminate the clearance between gears and achieve greater accuracy. Additionally, high reduction ratios are necessary for precise motion, as they allow finer positioning of the output shaft. The Harmonic Drive and the Wolfrom gearbox are common solutions for space and robotics due to their high reduction ratio and compactness. However, although the wolfrom gearbox has a greater strength-to-volume ratio, the Harmonic Drive reducer is preferred for applications that require high positioning accuracy and zero backlash due to the clearance between gears inherent to any gearbox. To address this limitation, an antibacklash system for wolfrom gearbox typology is presented and tested. The proposed solution shows a complete removal of the backlash and enough stiffness under the preloaded condition.