To counter complexity of spiral bevel gear geometry

this paper presents a mathematical model for calculating the steady bulk temperature field of spiral bevel gears based on the thermal transferring theory. Firstly

the mesh generation of finite element of the tooth of spiral bevel gear is discussed by using the 8-nodes three-dimensional finite element. Secondly

the authors develop the functional of the steady bulk temperature field of spiral bevel gear through the agency of variation principle and a method for calculating friction heat flow on the meshing tooth surface. Thus

the solution of steady bulk temperature field can be transformed into solving linear algebraic equations. Finally

this paper gives a calculating example and discusses the effect of a lot of factors （such as thermal physical parameters

geometric parameters and working conditions

etc.） on steady bulk temperature field of spiral bevel gear. The calculation results in this paper are in agreement with steady bulk temperature field of spiral bevel gear given in . It shows that this method presented by authors is reasonable and effective.