Investigation about Torque Fluctuation of Single Thread Worm Gear for EPS

Abstract

We had proposed the worm gear with new tooth profile for Electric Power Steering (EPS) which could make the worm wheel diameter small. This new tooth profile was derived by solving subject of the fundamental factor which reduced efficiency from a viewpoint of meshing, the strength, and the friction of the worm gear. In this paper, in order to reducing torque fluctuation in a high torque of stationary steering about this new tooth profile, from a view point of load distribution of worm gear, new modification method of this new tooth worm gear was found out. Verifying the effect of this modification, the gear was actually manufactured, and by measuring torque fluctuation of worm gear, the torque fluctuation was verified to reduce in spite of single thread worm gear.