Comprehensive Analysis of Transmission Error & Misalignment Effects in a Geared-Rotor System and Its Control with Active Magnetic Bearings: Dynamic Modelling and Experimental Assessment

Gears play a crucial role in efficiently transmitting power and torque in heavy machinery industries. To prevent unexpected failures, it is essential to study and analyse gear vibration patterns. Gear defects like eccentricity, gear run-out, transmission error, and misalignment are closely associated with periodic variation of mesh stiffness and damping, which originates a family of sidebands centred on the tooth mesh frequency and its harmonics. The multi-harmonic nature of the response necessitates the need of active vibration control devices like magnetic bearings to attenuate sub and super-harmonic frequency responses.

This research proposes a novel misaligned transmission error model integrated with the phenomenon of angular shaft misalignment incorporating sideband harmonics in both the forward and backward frequencies for precise diagnosis of misalignment.

The dynamic analysis of the proposed model of a geared-rotor system is simulated numerically, and a thorough experimental investigation of a geared-rotor test rig under three alignment conditions are presented. Two active magnetic bearings (AMBs) are used as an integral component in a geared rotor system to minimise two axes transverse vibration. A PID controller is modelled and utilised to stabilize the vibration by adjusting gain parameters.

This paper uses orbital and full spectrum plots for the analysis, and also contrasts the response with and without the usage of AMBs.