Patent ID: 8876384

Claim:
A hydrodynamic bearing assembly comprising: a shaft; a sleeve having a shaft hole formed therein so that the shaft is rotatably inserted thereinto; first dynamic pressure generation grooves provided in at least one of an outer surface of the shaft and an inner surface of the sleeve and having a herringbone pattern including repeated V-shaped grooves in which upper and lower wings are provided so as to generate dynamic pressure in a lubricating fluid filling a bearing clearance formed between the shaft and the sleeve at the time of rotation of the shaft; and second dynamic pressure generation grooves provided in at least one of an outer surface of the shaft and an inner surface of the sleeve and having a herringbone pattern including repeated V-shaped grooves in which upper and lower wings are provided so as to generate dynamic pressure in a lubricating fluid filling a bearing clearance formed between the shaft and the sleeve at the time of rotation of the shaft, wherein the first dynamic pressure generation grooves have a part of the V-shaped grooves of which the upper wing is longer than a lower wing among a plurality of V-shaped grooves, and the second dynamic pressure generation grooves are disposed below the first dynamic pressure generation grooves in an axial direction and have a part of the V-shaped grooves of which the lower wing is longer than an upper wing among a plurality of V-shaped grooves.