Transmission Mechanism Combining Self-Excited Vibrations and One-Way Clutches

Abstract

We propose a new transmission mechanism that is compatible with high-speed downsizing motors. This mechanism adopts the “pulse drive transmission” (PDT) principle. Similar to the electrical switching converter, the PDT principle allows variable velocity ratios regardless of geometry (cf. the radius relationship is essential for the gear principle as the geometry). According to this similarity, the PDT principle is expected to maintain low inertia even at large velocity ratios and to increase the amount of transmitted power by the dependence of transfer frequency on rotational velocity. Thus, the PDT principle is suitable for high-speed motors. This study employed self-excited vibration in the PDT principle to eliminate the engagement controls that caused problems at high speed in a previous study. Simulations and prototype tests demonstrated that the proposed mechanism, combining self-excited vibrations by magnetic nonlinear springs and one-way clutches, achieves the desired behavior based on the PDT principle and is capable of power transmission at several velocity ratios and rotational speeds. In particular, performance evaluations under steady-state operations showed that the maximum input torque, maximum power transmission, and maximum efficiency were 20.9 ± 0.18 N m, 1.0 kW, and 79.8%, respectively.