Patent ID: 7753590

Claim:
A bearing unit comprising: a radial bearing for bearing in a circumferential direction of a shaft, the radial bearing having an outer peripheral surface that has a circular sectional shape as viewed in the axial direction; a thrust bearing for bearing one end in a thrust direction of said shaft; a housing provided on the outside of said radial bearing and said thrust bearing, said housing filled with a viscous fluid, the housing having an inner peripheral surface that has a cross-sectional shape that, as viewed in the axial direction, is defined by at least one of a plurality of intersecting arcs and a plurality of substantially straight intersecting lines, such that intersections of the at least one of the plurality of intersecting arcs and the plurality of intersecting lines are vertices of the cross-sectional shape of the inner peripheral surface; a seal member united with said housing so as to contain said radial bearing and said thrust bearing in a sealed state, said seal member having a shaft passing hole through which said shaft is passed; and a passage for discharging air present inside said housing, said passage formed between said inner peripheral surface of the housing and said outer peripheral surface of the radial bearing and bounded in part by a vertex of the inner peripheral surface of the housing, and said passage providing communication between said one end and the other end in said thrust direction of said shaft projecting from said radial bearing, wherein a cross-sectional shape of said passage is a shape including at least one acute angle, the acute angle being on a plane parallel to the cross-sectional shape of the passage.