The gear meshing principle, namely the conjugate surface principle, is the basic method to study the contact transmission of two conjugate surfaces. Different from the meshing principle of other types of gear transmission, the contact surface of spiral bevel gear transmission is local conjugate, strictly speaking, it is point contact conjugate. This paper will mainly study the meshing principle of spiral bevel gears and the theoretical knowledge of conjugate contact.

The tooth surface of spiral bevel gear is two moving surfaces in space. As shown in the figure, set the two surfaces as 1s and 2s, and establish the coordinate system fixed with each other on the two surfaces σ1(t)、 σ2 (t), when two surfaces contact at a point m in space, the equation shall be satisfied

This paper mainly discusses the meshing principle of gears and the curvature relationship of spatial conjugate surfaces, and briefly introduces the local conjugate contact and tooth surface curvature correction of spiral bevel gears.