Closed loop lubrication system for moving magnetic media

Abstract

A data storage system is described with a system for controlling the amount of lubricant being dispensed from the reservoir using a feedback loop that includes at least one sensor output for a physical parameter inside device such as temperature, humidity and fly-height. In one embodiment the lubricant reservoir housing is equipped with a movable shutter over an aperture in the lubricant reservoir housing. The area of the aperture through which the lubricant vapor can pass is controlled by moving the shutter. In another embodiment the lubricant reservoir housing is supplied with a lubricant diffusion packet such as an effusion cell or diffusion tube containing liquid lubricant. An energy source for the lubricant diffusion packet allows the temperature of the lubricant and, therefore, its vapor pressure, to be increased when the need for additional lubricant is sensed. In a preferred embodiment the output from a Quartz Crystal Microbalance (QCM) with an overcoat similar to that used on a disk is used to measure the degree of lubricant saturation inside the drive by sensing the change in the frequency of a crystal oscillator due to the lubricant adsorbing on a surface of the QCM.