This paper introduced the rule of selecting the type of flying shears, driving system, cutting positon and electromotors; It emphatically described the viewpoint that gear driving system of flying shear should eliminate backlish mechanism while leaving suitable backlish.

In recent years, the requirement of these fields, such as aeronautic, aerospace and robot, demands more on the accuracy, vibration, noise and reliability in the gear driving system.

Modeling and modal analysis for the torsional vibration of multi-stage gear transmission system;

Utilizing the correlated theory of parallel engineering and graph theory,let the relationship of precision design among every component parts of the gear transmission system be connected together to establish the relationship model.

For mechanical fault in the gear transmission system difficult to diagnosis,an improved clustering method was presented based on the DBSCAN(Density-based spatial clustering of application with noise) by using the concept of grid processing.

Aim\ To probe into fundamental problems in fault diagnosis of gear transmission systems.

On the basis of experimental investigation, an empirical model of the relation between the increment of fatigue strength due to low amplitude load strengthening and the critical load of transmission gears is worked out.