Patent ID: 6939047

Claim:
A dynamic pressure bearing device comprising: a rotary shaft; a dynamic pressure bearing member for supporting the rotary shaft; two radial dynamic pressure bearing parts formed in an axial direction in a radial opposing region of an inner circumference surface of the dynamic pressure bearing member to an outer circumference surface of the rotary shaft; a thrust dynamic pressure bearing part formed in a thrust opposing region of an end surface in the axial direction of the dynamic pressure bearing member to an end surface in the axial direction of a rotary member rotating with the rotary shaft; a lubricating fluid continuously filled in a bearing space comprising the two radial dynamic pressure bearing parts and the thrust dynamic pressure bearing part; and a bypass passage for pressure release for communicating between a space, which is positioned between one of the two radial dynamic pressure bearing parts and the thrust dynamic pressure bearing part, and a space positioned on an outer side in the axial direction of the other radial dynamic pressure bearing part, retaining the lubricating fluid, communicating with the other radial dynamic pressure bearing part.