A novel wave generator design of harmonic drive based on non-uniform rational B-splines

Abstract

This paper proposes a novel design for the wave generator in harmonic drives using non-uniform rational B-splines. The approach allows for greater flexibility and precise control over the wave generator profile by adjusting the number and the position of the control points. The purely kinematic error and the caterpillar effect are briefly introduced. A finite element model is employed to validate the mechanical properties. Different wave generator profiles, created with varying numbers of control points (four, five, and six), are analyzed regarding curvature, kinematic error, caterpillar effect, and mechanical performance. Results show that the proposed design significantly reduces purely kinematic errors and improves stress distribution compared to traditional elliptical cam designs, enhancing engagement and overall system performance. This innovative method offers a more efficient and adaptable solution for optimizing harmonic drives.