Abstract
A method of designing hypoid gear drives in which transmission errors are robust against misalignment under a loaded state was investigated for the purpose of reducing gear noise caused by the final drive unit of vehicles. The effect of the lengthwise curvature of a hypoid gear on transmission error under load was predicted by using a newly developed tooth contact analysis (TCA) technique. The effect of the lengthwise curvature was also examined by evaluating transmission errors under a loaded state in a machine that had provisions for displacing the pinion and gear in the P, G and E directions. It was confirmed that a face-hobbed gear design makes transmission error robust against displacement error along the pinion axis. An example is shown where transmission error under load was reduced successfully by taking advantage of this transmission error characteristic of facehobbed hypoid gears. Furthermore, this paper proposes a method of designing robust tooth surface modifications on the basis of the Quality Engineering Method. It was confirmed that the proposed method provides a hypoid gear surface that keeps transmission error at a low level under load.
