Motor with aerodynamic pressure bearing mechanism

A motor that is used for rotating a scanning member for scanning with a laser light or a fan for blowing wind, the motor being attached to a rotating axis and provided with an aerodynamic pressure bearing mechanism, the mechanism comprising:

• said rotating axis;
• a fixed member having a surface facing the surface of the rotating axis with a predetermined bearing clearance;
• and herring bone grooves composed of N number of grooves placed on the surface of the rotating axis at regular intervals in the rotational direction and configured to generate dynamic pressure within said bearing clearance during rotation,
• wherein said herring bone grooves are composed of N number of grooves, and the respective grooves are disposed at an intake angle β (0<β≦90°) towards the center in the axial direction of the rotating axis with the edge of one end part in the axial direction of said rotating axis as one end of the grooves and at a ratio α between the length of said grooves in the axial direction and the axial diameter of the rotating axis being in the range of approximately 0.2 to 0.8, wherein said grooves are composed of N number of grooves at positions where maximal pressure values of dynamic pressure variation in said bearing clearance caused during rotation at a rotation frequency of M (40<M≦60:
• krpm for units) in an environment in which the ambient temperature is approximately 60° C. or less and the ambient humidity is approximately 60% RH appear, and at intervals such that N number of minimal pressure values appearing in alternation with said maximal pressure values are equal to or lower than 1.7 atm.