Research on Dynamic Characteristic of the Rotors Connected by the Misaligned Gear Coupling

The misalignment of gear coupling is the most commonly observed fault in industry fields. It can cause great harm. In order to find out its physical mechanism and dynamic charactersic, a new Finite Element Modal of misaligned rotor-bearing system with gear coupling is presented in this paper. By considering the forces and moments which applied on rotor in two typical misaligned conditions, i.e. parallel and angular misalignment, the dynamic equation is established. Through simulation and dynamic analysis of two-span rotor system with misalignment, quantitive relationship between the misalignment and steady-state response is obtained. Meanwhile, an investigation on phase of twice rotational speed freqency (2X) reveals that in parallel misaligned condition, the phases of two sides of coupling are same, while in angular misalignment condition the phases are opposite (almost 180°difference). This feature can be used as an important reference when confirming a misalignment fault.