Active magnetic dampers for controlling lateral rotor vibration in high-speed rotating shafts

摘要

High-speed rotating machinery frequently operates supercritically, traversing self-excited resonance during startup and shutdown. The rotor's peak radial displacement often occurs during this critical transition, thus defining minimum clearances between the rotor and stator. Squeeze film dampers (SFDs) are frequently used to reduce lateral rotor vibration (LRV), but their passive nature imposes design and performance limitations. An alternate approach, the subject of this paper, employs active magnetic dampers (AMDs) to overcome the inherent tradeoffs associated with squeeze film dampers. This paper details the design, fabrication and experimental demonstration of an AMD for reducing LRV in a high-speed rotating shaft through its critical speed. A finite-element method (FEM) model of a highspeed flexible shaft with an AMD mounted proximal to a compliant bearing support is developed and parameterized using test data. Different actuator locations are evaluated using the FEM model, revealing that the primary mechanism for LRV reduction is the moment exerted about the compliant bearing. Performance of a SFD is simulated for comparison, revealing that the AMD more effectively reduces LRV. Peak radial deflection is reduced by an average of 79% through the shaft's first critical speed.