Aerodynamic and Hydrodynamic Bearings
The most commonly used and most numerous Aerodynamic bearing in the World is the slider bearing that is used in all computer Hard Disc Drives, it is known as a Flying Head. Also the new Hard Disc Drives are using a Grooved Hydrodynamic Bearing as the main spindle bearing. The numbers of these bearings in daily use must now be numbered in millions.
The reason for the development of these bearings has been to promote operation at high rotational accuracy so that Data Tracks of the order of 30,000 Tracks Per Inch can be reliably used.
Aerodynamic and Hydrodynamic Bearings are made in a variety of different types, but all types rely on the relative velocity between the bearing surfaces to entrain the fluid into the bearing clearance and generate a pressure profile. The slider and plain cylindrical journal bearing shown below in the sketches show this latter principle.
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