Method and apparatus for lifetime prediction of gas lubricated interfaces in data storage devices

An apparatus, for increasing the surface wear rate associated with the relative tangential motion between two normally proximate surfaces, said surfaces being surfaces of a magnetic recording head, and disk media, respectively, and said surfaces being separated, or tending to be separated, by a thin layer, or partial layer, of gas entrained between the surfaces due to said motion taking place in an atmosphere of said gas, and said device comprising:

• a. a means for initiating and maintaining said relative tangential motion in a controlled manner, which includes a spindle capable of rotation, and a means for clamping the disk media to said spindle, and
• b. a means for keeping the surfaces normally proximate, and
• c. a means for containing, and maintaining the purity of, the gaseous atmosphere surrounding the interface, and
• d. a means for generating ultrasonic pressure waves in said gaseous atmosphere, with a frequency, or frequency range, which is chosen, or tuned, so as to achieve resonance of, or resonance involving, the thin layer, or partial layer, of gas between said surfaces, and
• e. a means for directing said ultrasonic pressure waves to impinge upon said layer, or partial layer, of gas between the surfaces, and
• f. a means for indirect measurement of the extent of interface wear or degradation during operation of the apparatus.

A magnetic disk drive information storage device, including:

• a) a single magnetic disk or plurality of magnetic disks, arranged concentrically about the axis of rotation of a common spindle, and
• b) a plurality of magnetic recording heads, mounted on an actuator which controls the radial position of the recording heads with respect to circular tracks of data which are written on the disk surfaces, and
• c) a motor which turns the spindle and causes the disks to co-rotate, thereby creating relative tangential motion between the disk surfaces and the magnetic recording heads, and
• d) a plurality of gas bearings formed due to said relative tangential motion, said gas bearings being located at the interface between each magnetic recording head and the disk surface adjacent to the same magnetic recording head, and
• e) an electronic means for causing data to be written and read from the surfaces of the disk during operation, and for controlling said actuator and said motor, and
• f) a means for enclosing or filtering the gaseous atmosphere which surrounds the magnetic recording heads and the disk surfaces, and
• g) a means for generating ultrasonic sound in said gaseous atmosphere during normal operation of the device, with a frequency range which includes one or more resonance frequencies of said gas bearings, and
• h) a means for directing said sound to impinge upon, or have increased intensity in, regions of said atmosphere which include said gas bearings, so that the frequency and intensity of physical contact between the heads and disk surfaces is increased during periods of normal operation, and the usable lifetime of the device is thereby reduced for testing purposes.