Patent ID: 7862237

Claim:
A hydrodynamic bearing, comprising: a shaft; a sleeve provided with a bearing hole having a closed end of one end and an open end at the other end and wherein the shaft is inserted into the bearing hole so as to be capable of relative rotation; a cover configured to cover an end face and an outer peripheral surface of the sleeve at the open-end side thereof and at a distance forming a gap; a connecting channel configured to connect a space region at the closed-end side of the sleeve and a gap region between the cover and the open-end side of the sleeve; a lubricant retained in a space in the vicinity of the sleeve and including the space between the cover and the sleeve; a sleeve end face gap section configured to be formed in order that the lubricant moves from the connecting channel to the bearing hole between the cover and an end face at the open-end side of the sleeve and including an introducing gap section formed in close proximity to an opening section of the connecting channel; a vent hole configured to be formed in a space between an inner peripheral surface of the cover and an outer peripheral surface of the sleeve so as to connect with outside air and connected to the introducing gap section; and a first lubricant reservoir section configured to be formed between the inner peripheral surface of the cover and the opposing outer peripheral surface of the sleeve by forming a depression in one of the sleeve and the cover, or both thereof so as to provide a space larger than the end face gap section, capable of storing the lubricant therein, and shaped such that a gap between the inner peripheral surface of the cover and the outer peripheral surface of the sleeve grows larger as a distance from the vent hole in a circumferential direction decreases.