Hitachi GST Assigned Patent

Hitachi Global Storage Technologies BV, Amsterdam, The Netherlands, has been assigned a patent (8,189,291) for "conical fluid dynamic bearings having improved stiffness for use in hard-disk drives."

The co-inventors are Chiaoping Ku, Fremont, CA, Fu-Ying Huang, San Jose, CA, Lidu Huang, Danville, CA, and Hitoshi Shindo, San Jose, CA

The abstract of the patent published by the U.S. Patent and Trademark Office states: "Approaches for a fluid dynamic bearing (FDB) system for use within a hard-disk drive. A fluid dynamic bearing (FDB) system may comprise an upper conical bearing and a lower conical bearing that are both disposed along a stationary shaft on which a magnetic-recording disk is rotatably mounted. The upper conical bearing and the lower conical bearing may have different cone angles, diameters, and/or lubricants to produce a desired difference in stiffness between the first conical bearing and the second conical bearing. By adjusting characteristics of the fluid dynamic bearing (FDB) system to achieve the desired bearing stiffness ratio, the tendency for the magnetic-recording disks to experience a sustained vibration when the hard-disk drive receives a mechanical shock is reduced. By preventing the magnetic-recording disks from sustained vibration after a mechanical shock, data may be written to and read from the magnetic-recording disks with greater reliability."

The patent application was filed on Oct. 22, 2010 (12/910,488).