Patent ID: 7510330

Claim:
A hydrodynamic bearing comprising: a bearing sleeve; a rotational shaft supported for rotation by said bearing sleeve; a bearing gap formed between said bearing sleeve and said rotational shaft; lubricating oil contained within said bearing gap; at least one hydrodynamic pressure-generating groove formed at an inner peripheral surface of said bearing sleeve; an oil reservoir further comprising a gradually expanding section located in a position distanced from said at least one pressure-generating groove and a first larger inner diameter section located adjacently to said gradually expanding section; a second larger inner diameter section located immediately below an opening of said bearing sleeve; and an oil-repelling peripheral groove located between said first larger inner diameter section of said oil reservoir and said second larger inner diameter section, wherein an opening of said oil-repelling peripheral groove gradually widens towards the inside of said bearing sleeve, wherein a first side surface of said oil-repelling peripheral groove forms an oil splash back wall surface, wherein said lubricating oil is filled to a position where a non-operational fluid level of said lubricating oil is located within said first larger inner diameter section, and wherein a configuration of said first side surface of said oil-repelling peripheral groove prevents overflow and scatter of said lubricating oil beyond said first side surface of said oil-repelling peripheral groove even when an external force is received by said hydrodynamic bearing.