Air-gap effect on single axis vibration of electromagnetic braking using eddy current on bearing cage

Abstract

An electromagnetic braking system using eddy current experiment was conducted to study the behavior of the system in terms of vibration. Brake disc used which is Al6061 has a displacement in z-axis direction which occurred because of the repulsive force generated on both sides of the disc as drag force from electromagnetic braking. This study aims to analyze the vibration behavior when braking occurred in different initial speeds of DC motor and different air gap cases. Smaller air-gap will produce high braking torque due to the increasing of magnetic field density. The higher the force generated, the vibration of the disc may illustrate different behavior of the vibration in the structure. Test rig was developed using sensor of accelerometer and data acquisition of NI-DAQ with the use of Dasylab for the measurement and instrumentation purposes. Findings shows that the electromagnetic braking force generated in smaller air-gap between electromagnetic poles and rotating conductive disc during the braking using eddy current has damped the vibration occur in the structure of bearing cage.