| 摘要 |
<p>PURPOSE:To adapt a bearing to high speed rotation by providing a layer of continuous pores having porosity smaller than that of a graphite backing on the surface of the backing with continuous pores having a specific porosity to form a static pressure air bearing so as to eliminate seizure and spots on a shaft. CONSTITUTION:A porous air bearing 1 is made by forming SiC layers 2 (e.g. porosity 3%) on a graphite backing 3 (e.g. porosity 6%, average pore diameter 10mum) and by providing a metal cover 4. When air is put into an air hole 5 from a compressor as shown by an arrow A and flows through the SiC layer 2 that is the outer layer as shown by an arrow B, the pressure becomes high, and it is reduced in the graphite backing 3 as its porosity is high and an air sump is generated. The pressure of the air becomes high in the inner SiC layer 2 again and the air spouts out to the shaft surface as shown by an arrow C. Even if an air hammer is generated in the air entering the bearing, effect on the amount of spouted air and air pressure is small since the inside of the bearing is an air sump, which gives stable bearing rigidity suited for high speed rotation.</p> |
