Abstract
To meet the demands such as energy saving and smaller power source equipment in buildings, Mitsubishi has developed high-speed elevators introducing a new system, which employs the helical gear type traction machine and the VVVF control, first in the world. This paper describes the basic design concept concerning fatigue stress, impact stress, pitting, wear and vibration of the helical gear that is an important part to the traction machine and introduces the outline of the results of the development.