Patent ID: 7246945
Filing Date: 2007-07-24
Classification: F16C,G11B,H02K

Abstract:
1. An oil dynamic bearing having a bearing center comprising: a fixed unit; a rotary unit; and two bearing portions for rotatably supporting the rotary unit about a rotational axis, in which at least one of the opposed surfaces of the fixed unit and the rotary unit is formed with a plurality of dynamic pressure generating grooves, and an oil is held in the minuscule gap between the fixed unit and the rotary unit including a part or the whole of the dynamic pressure generating grooves; wherein the two bearing portions include: first and second taper seal portions, each of the taper seal portions having an outer pressure-side seal end portion communicating with an atmosphere and an inner pressure-side seal end portion connected separately and respectively to each of bearing far end portions of the two bearing portions, the bearing far end portion defined as one end of the bearing portion farther from selected one of the rotational axis and the bearing center of the oil dynamic bearing; and a third taper seal portion having an outer pressure-side seal end portion communicating with the atmosphere and an inner pressure-side seal end portion connected in common to each of bearing near end portions of the two bearing portions, the bearing near end portion defined as one end of the bearing portion nearer to selected one of the rotational axis and the bearing center of the oil dynamic bearing; and wherein the two bearing portions have different directions from the bearing near end to the bearing far end, and each taper seal portion has a gradually wider distance between the opposed surfaces of the fixed unit and the rotary unit at an observing point in proportion to the observing point moving from the inner pressure-side seal end portion to the outer pressure-side seal end portion.