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The procedure of 3-D finite element meshing for skewed rotor induction motors has been developed. In this method, the mesh distortion caused by the rotor-node rotation for skew modeling is reduced using the iterative node displacement and element swapping. The advantages and necessity of the proposed method are confirmed by comparing the conventional mesh-generation method and motor experiments. It is revealed that the accuracy of the calculated loss is considerably deteriorated by the distorted mesh and it is significantly improved by the proposed mesh-generation procedure.

A novel flying height-attitude testing system was developed based on white-light interferometry. Flying heights at three desired locations on the slider surface can be determined simultaneously with this system and, thus, slider attitude can be fully determined from the measurement results. Load and unload processes were systematically studied with this system and some details were revealed.

The current design of magnetic-disk head sliders needs an extra margin of flying height for manufacturing tolerance or environmental variation. To reduce this margin, we have developed active-head sliders. These sliders carry an unimorph piezoelectric microactuator, and their flying height can be controlled. After simulating the piezoelectric deflection of the actuator and flying characteristics of air-bearing surfaces, we designed two types of active-head sliders (five-pad type and four-pad type) and fabricated them by silicon microelectromechanical system (MEMS) processing. In tests, the sliders flew over a glass disk, and the observed stroke of the actuator (30 nm/5 V) was considered large enough to control the flying height. The large area at the rear end of the four-pad-type slider structure is sufficient to carry conventional read/write heads. Moreover, the slider fabrication process will not destroy the heads. We, thus, conclude that the active-head sliders can be applied for practical use easily, and their flying height will be significantly lower than that of conventional disk head sliders.

We investigated the friction force between the trailing edge of the center pad or rail of negative pressure sliders and the textured disk surface as a function of flying height at reduced air pressure. In addition, we proposed the simple contact model and compared experimental friction force with calculated contact force to evaluate the influence of slider design parameters on the contact force. Results show that the contact force is significantly influenced by the pitch air-bearing stiffness, the distance between the pivot point and the contact point, and the interference pitch angle defined as the difference between the flying pitch angle on the smooth glass disk and the contact pitch angle on the textured disk.