Patent ID: 7160031

Claim:
A thrust dynamic pressure bearing, comprising: a bearing rotary side member having a first bearing surface; a bearing fixed side member having a second bearing surface, said first and second bearing surfaces being mutually opposed to each other across a gap in an axial direction, said gap being filled with lubricating oil; herringbone dynamic pressure generating grooves provided in one of said first and second bearing surfaces such that dynamic pressure of said lubricating oil is induced upon rotation of said bearing rotary side member relative to said bearing fixed side member, each of said herringbone dynamic pressure generating grooves having a middle flex part, said one of said first and second bearing surfaces constituting a pressure generating groove surface, and the other of said first and second bearing surfaces constituting a groove-facing surface; and at least one auxiliary groove provided in one of said pressure generating groove surface and said groove-facing surface, said at least one auxiliary groove communicating from an inner periphery of said one of said pressure generating groove surface and said groove-facing surface to an outer periphery of said one of said pressure generating groove surface and said groove-facing surface.