Finite element modelling and stress analysis of helical gear teeth

Abstract

Because of the lower dynamic load, the noise level during operation and the demand for lighter and smaller automotive transmissions, helical gears have become the subject of attention. The three-dimensional way of calculating the root stresses of helical gears gives realistic results. This paper explains about the geometry of helical gears by simple mathematical equations, the load distribution for various positions of the contact line and the stress analysis of helical gears using the three-dimensional finite element method. A computer program has been developed for the stress analysis of the gears. Root stresses are evaluated for different positions of the contact line when it moves from the root to the tip. To check the validity of the present program, the changes in the trend of the maximum root stress values at various places of the tooth along the face width have been compared with the experimental results from other literature. A parametric study is made by varying the face width and the helix angle to study their effect on the root stresses of helical gears. Based on this investigation the effect of helix angle and face width on the root stresses of helical gears has been clarified for different positions of the contact line.