Face gear transmission is a kind of gear transmission in which cylindrical gears mesh with bevel gears. Angle between two wheel axes γ = At 90 °, the teeth of bevel gear will be distributed on a plane, that is, face gear. Straight teeth and helical teeth are commonly used in foreign face gear transmission. They have been applied in helicopter split transmission system. Compared with the existing bevel gear transmission mode, it can reduce the weight of gearbox by 40% and increase the bearing capacity by 35%. It is of great significance to improve the thrust weight ratio and reliability of helicopter transmission system. At present, the domestic Helicopter Power Research Institute, manufacturing enterprises and relevant universities have begun to track and research the spur and helical gears.
Arc tooth surface gear transmission is a new transmission form, which is meshed between staggered shaft arc tooth cylindrical gear and arc tooth surface gear. At present, Northwest University of technology is studying the design and processing of arc gear, and has achieved phased results. On the basis of establishing the mathematical model, the author uses the reverse modeling technology to establish the three-dimensional CAD model of arc gear, which lays a foundation for further performance analysis and NC machining simulation of arc gear.
Arc tooth surface gear is a new type of gear. When using reverse technology to design free-form surface, first analyze the function of the surface in the actual work, and then select the corresponding design method according to the needs. For example, the working tooth surface is the meshing surface, and its surface quality directly affects the meshing performance and NC machining simulation. Therefore, when constructing the working tooth surface, we should not only strictly control the distance error between the surface and the point cloud, but also make the change of surface curvature continuous. The tooth root transition surface is a non meshing surface, which mainly affects the bending stress of the tooth root and has low requirements for the surface quality. When constructing the surface, the requirements of tooth surface error and surface continuity can be relaxed appropriately.