Active Correction of Dynamic Mass Imbalance for a Precise Rotor

An adaptive mass imbalance correction method for a precision rotor that is formulated in frequency domain is introduced. Various imbalance correction methods are developed and successfully implemented since mass imbalance of a precise rotor has been one of the critical volume production issues for decades, especially in the data storage industry. Meanwhile the volume manufacturing tolerance of the mass imbalance has been ever tightened as the data storage density has been increasing. Recognizing the limitation of the present imbalance correction methods and the practicality of fine-tuned rotor balance for volume production, this paper delivers development of an adaptive dynamic rotor balance scheme, which is of great worth. An application of frequency-based control method popularly used for repeatable runout compensation for the mass imbalance enables reliable and accurate balancing of precision rotors. The use of least mean squares algorithm for the formulation of the control law has improved the robustness of the imbalance correction and improved manufacturing yields.