Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Hisaaki Yano

Keigo Kusaka

Takafumi Asada

Takao Yoshitsugu

Koji Hirata

Yoshihito Watanabe

Koichi Fujimoto

With a hydrodynamic bearing device, a first gap Gis formed between a shaftand a sleeve. A second gap Gis formed between a sleeve capand the sleeve, and holds a lubricant. A thrust bearing memberis disposed near the inner peripheral surface of a center holeof the sleeve cap. A third gap Gis formed between the thrust bearing memberand the sleeve cap, and is open to the atmosphere. A fourth gap Gis formed between the thrust bearing memberand the sleeve. The lubricantcirculates along a circulation passage that includes a communicating path, the first gap Gand the second gap G

Hydrodynamic bearing device, and spindle motor and information apparatus equipped with same

A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Hydrodynamic bearing device, spindle motor and hard disk driving apparatus having the hydrodynamic bearing device

Growing community of inventors

Ehime, Japan

Hisaaki Yano