GAS DYNAMIC PRESSURE BEARING

PURPOSE:To provide a gas dynamic pressure bearing having little change of the friction coefficient under the relatively high face pressure, having no constraint on the posture when a motor is operated, capable of keeping the bearing friction torque small at the time of a start even when starts and stops are frequently repeated, generating no dust from the bearing, and capable of being used in the clean environment. CONSTITUTION:A gas dynamic pressure bearing is constituted of the receiving member of a main shaft 5 integrated with the first and second thrust plates 2, 3 in direct contact with both ends of a radial bearing member 1 and a radial sleeve 4 while the inner periphery 4a and both end faces 4b, 4c are faced and cooperated with the outer periphery 1a of the radial bearing member 1 and the mating faces 2a, 3a of the first and second thrust plates. A dynamic pressure generating groove C is provided on either one of both end faces 4b, 4c of the radial sleeve 4 or the mating faces 2a, 3a of the first and second thrust plates, and a uniform amorphous carbon hydride (a-C:H) film (b) is provided on at least one of opposite sliding faces of the gas dynamic pressure bearing.