Design and Validation of a Novel Quadruple-Disk CYcloidal Compact-Cam Reducer for Robotic Applications: Q-CYC

Abstract

Reduction gearboxes play a key role in robotics actuation. Among the existing designs, cycloidal gears are gaining popularity for their efficiency, torque density, and robustness. The compact-cam architecture is a variant of the classical cycloidal drive that employs two rigidly coupled cycloidal disks to achieve high reduction ratios within a minimized radial profile. However, this design tends to suffer from low regularity, which can degrade performance in robotics applications. Building on the concept of the double disks with a phase offset to increase regularity, in this work, we present a novel Quadruple-disk CYcloidal Compact-cam (Q- CYC) reducer that applies the phase-offset principle to the compact-cam architecture. By incorporating two additional coupled disks, the proposed design enhances load distribution and motion regularity. Two open-source, 3D-printed prototypes (one implementing the conventional compact-cam transmission and one featuring the presented quadruple-disk architecture) are designed and experimentally evaluated. The analysis focuses on friction, gear play, backdriveability, and speed regularity, demonstrating that the quadruple-disk design offers significant improvements. Therefore, the results validate the effectiveness of the proposed approach in addressing known performance limitations of cycloidal compact-cam reducers, reducing gear play and improving both speed regularity and backdrivability.