Disc drive spindle motor having hydro bearing with optimized lubricant viscosity

摘要

PCT No. PCT/US96/17131 Sec. 371 Date Oct. 10, 1997 Sec. 102(e) Date Oct. 10, 1997 PCT Filed Oct. 25, 1996 PCT Pub. No. WO97/16828 PCT Pub. Date May 9, 1997A disc drive data storage system according to the present invention includes a housing, a central axis, a stationary member which is fixed with respect to the housing and coaxial with the central axis, and a rotatable member which is rotatable about the central axis with respect to the stationary member. A stator is fixed with respect to the housing. A rotor is supported by the rotatable member and is magnetically coupled to the stator. At least one data storage disc is attached to and is coaxial with the rotatable member. A hydro bearing interconnects the stationary member and the rotatable member and includes a blend of base fluids. The base fluids in the blend are selected such that one of the base fluids has a viscosity that is greater than a desired viscosity selected for the disc drive, another of the base fluids has a viscosity that is less than the desired viscosity and the blend of base fluids has a viscosity that is within a selected range of the desired viscosity.