Patent ID: 6952324

Claim:
A disc drive storage system comprising: a housing having a central axis; a stationary member that is fixed with respect to the housing and coaxial with the central axis; a stator fixed with respect to the housing; a rotatable member that is rotatable about the central axis with respect to the stationary member; a rotor supported by the rotatable member and magnetically coupled to the stator; at least one data storage disc attached to and coaxial with the rotatable member; an actuator supporting a head proximate to the data storage disc for communicating with the disc; and a hydro bearing interconnecting the stationary member and the rotatable member and having working surfaces separated by a lubricating fluid comprising one or more base fluids and at least one additive, wherein the at least one additive reduces the rate of viscosity decrease of the base fluid as a function of increasing temperature, and wherein a percent power reduction for the lubricating fluid at temperatures below about 10° C. is higher than a percent stiffness reduction at temperatures above about 70° C.