THE SELF-ACTING, SUBAMBIENT FOIL BEARING IN HIGH-SPEED, CONTACT TAPE-RECORDING WITH A FLAT HEAD

The mechanics and tribology of a flat head for high-speed, contact tap e recording is presented. Experiments performed on a ''row-bar'' of th in-film disk heads where the tape is wrapped only on the edge opposite to the heads showed very stable contact for a wide range of tape spee ds and very low wear. A model of the interface showed that a self-acti ng, subambient air bearing forms near the leading wrapped corner This suction is caused by the expansion of air into the diverging gap on th e upstream side of the head-tape interface, which is unique to this wr ap geometry, and it is responsible for the stability and low contact p ressures. A bidirectional version of a flat head geometry is analyzed via modeling and suggestions are made for that design. This work also showed strong evidence of a threshold of contact pressure below which wear becomes negligible.