3D 프린팅 기법을 이용한 하모닉 드라이브(Harmonic Drive) 설계 및 응용 분석

초록

Harmonic drives have attracted increasing attention with the development of materials, parts, and related equipment. Harmonic drives exhibit high deceleration, high accuracy, and light weight. The stiffness of flexible splines according to the radial load is studied using a commercial FEM program to design the structure of the flexible spline and finite element to improve the weight and price competitiveness of harmonic drives. In addition, several studies have measured and compared friction coefficients based on 3D printed tread patterns. However, owing to the characteristics of plastic materials, a decrease in stiffness in the radial direction is inevitable. To prevent a decrease in stiffness in the radial direction, we designed and manufactured flex splines with a wrinkle shape. Through structural analysis, the reaction force and stiffness in the radial direction were determined. In addition, the maximum angle of the mound was derived by theoretical calculations, and the performance of the harmonic drive was compared with the results obtained in the mound experiment. Structural analysis shows that the shape of wrinkles decreased the stress and reaction force and increased the safety factor in comparison with that of the circular shape. During performance verification through continuous experiments, the developed harmonic drive showed continuous performance similar to that of an actual tank model. It is expected that the flex spline with a compliant spring and wrinkle shape will prevent a decrease in the radial stiffness.

키워드