Drive level slider-suspension vibration analysis and its application to a ramp-load magnetic disk drive

An experimental method employing a piezoelectric transducer and a dual channel laser Doppler vibrometer (LDV) is presented, that is capable of vibration analysis of the slider-suspension assembly in a production disk drive with minor modification. We then apply this method to a ramp-load disk drive to investigate the radial acceleration effect on slider dynamics at the beginning of radial loading motion while the suspension arm moves along the ramp structure. The results show that the slider's motion in the roll and vertical directions are strongly coupled by the radial vibration of the suspension, and that the radial acceleration at the beginning of the radial loading motion has only negligible effect on the parameters determining slider-disk contact. These parameters are the pitch, roll and loading velocities of the slider at the establishment of the air bearing, and they can be measured by the LDV during the ramp loading process by fixing the actuator and actuating the disk drive.