Experimental evaluation of a head assembly by using a piezoelectric tripod shaker

A piezoelectric tripod shaker and a seek-acceleration simulator system developed to evaluate the dynamic characteristics of a head assembly in a hard disk drive and to investigate the effects of vibration during the seek period are discussed. This shaker has three orthogonally placed piezoelectric devices that use flexible mechanisms to avoid interference from each other´s vibration. The shaker has a displacement of 4 μm, a frequency range of 10 kHz, and a mode isolation of over 20 dB. Experimental results of a head assembly, with a standard mini slider shaken in various directions, show that the sway mode (f3 mode) of the lateral (Y-shake) acceleration is dominant. The flying-height fluctuation is obtained during the seed period by using the seek-acceleration simulator system