Tc. Fu et Db. Bogy, SLIDER VIBRATIONS INDUCED BY RAMP-SUSPENSION INTERACTION DURING THE RAMP LOADING PROCESS, IEEE transactions on magnetics, 30(6), 1994, pp. 4170-4172
In our previous experimental investigation of the ramp loading process
for a 2.5 inch ramp-load disk drive employing a two beam laser Dopple
r vibrometer, we observed that the slider's approach velocity was not
controllable because of a vibrating motion that became excited as the
suspension moved down the ramp. Here we study the source of this vibra
tion and observe that it becomes excited each time when the slider rea
ches a certain Location above the disk, and its amplitude is sometimes
reduced at slower actuation speeds. By analyzing the frequency spectr
a of the slider's pitch, roll and vertical translation during loading,
we found that the vibration was primarily comprised of the last two m
odes. This motion was found to be correlated with the shape of the ram
p. Modification of the ramp profile effectively reduced the vibration,
resulting in a controllable approach velocity and a substantial reduc
tion in slider-disk contacts during loading.