Acoustic Noise and Vibration Reduction of Coreless Brushless DC Motors with an Air Dynamic Bearing

Title & Authors
Acoustic Noise and Vibration Reduction of Coreless Brushless DC Motors with an Air Dynamic Bearing
Yang, lee-Woo; Kim, Young-Seok; Kim, Sang-Uk;

Abstract
This paper presents the acoustic noise and mechanical vibration reduction of a coreless brushless DC motor with an air dynamic bearing used in a digital lightening processor. The coreless brushless DC motor does not have a stator yoke or stator slot to remove the unbalanced force caused by the interaction between the stator yoke and the rotor magnet. An unbalanced force makes slotless brushless DC motors vibrate and mechanically noisy, and the attractive force between the magnet and the stator yoke increases power consumption. Also, when a coreless brushless DC motor is driven by a $\small{120^{\circ}}$ conduction type inverter, high frequency acoustic noise occurs because of the peak components of the phase currents caused by small phase inductance and large phase resistance. In this paper, a core-less brushless DC motor with an air dynamic bearing to remove mechanical vibration and to reduce power consumption is applied to a digital lightening processor. A $\small{180^{\circ}}$ conduction type inverter drives it to reduce high frequency acoustic noise. The applied methods are simulated and tested using a manufactured prototype motor with an air dynamic bearing. The experimental results show that a coreless brushless DC motor has characteristics of low power consumption, low mechanical vibration, and low high frequency acoustic noise.
Keywords
Coreless BLDC motor;Slotless BLDC motor;Air dynamic bearing;Stator yoke;Mechanical-vibration;Acoustic noise;Power consumption;$\small{180^{\circ}}$ conduction type inverter;
Language
English
Cited by
1.
The Derivation of the Stability Bound of the Feedback ANC System That Has an Error in the Estimated Secondary Path Model, Applied Sciences, 2018, 8, 2, 210
2.
Analysis and design of a coreless permanent-magnet machine considering the winding shape by using a lumped equivalent magnetic circuit model, The European Physical Journal Applied Physics, 2014, 66, 2, 20902
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