Investigation of the thermal stiffness and thermal tooth profile modification of spur gears

Abstract

This paper first proposed the concept of thermal stiffness of gears and then calculated thermal stiffness using the finite element method and the analytical method, respectively. After that, based on the thermal stiffness, the thermal tooth profile modification of gears was studied. The results showed that the meshing thermal stiffness of tooth pair under the thermo-elastic coupling is a serial connection of elastic stiffness and modified thermal expansion stiffness. In addition, the meshing thermal stiffness of tooth pair decreases compared with the meshing elastic stiffness in the entire meshing region. There is only one intersection point of the distribution curves of the single tooth thermal stiffness and elastic stiffness along the meshing line. In the tooth root side of the intersection point, the thermal stiffness is larger than the elastic stiffness, and it is opposite in the tip side of the intersection point. It can be concluded from the thermal tooth profile modification parameters that the maximum amount of profile modification is the thermo-elastic coupling deformation of point B or D, with the modification index being 1.33.