Bearing device and exhaust turbine turbocharger

Abstract

The present invention improves the drainability of lubricating oil. The present invention comprises: a rotating shaft (); a journal bearing that is provided to the rotating shaft () and rotationally supports the rotating shaft (); a bearing housing part that houses the journal bearing; and a drain oil space chamber () that acts as an oil drainage passage that communicates with the bearing housing part, is provided along the periphery of the rotating shaft (), and is formed to open downward. Within a region that is in and above a horizontal plane H that passes through the center of the rotating shaft (), the smallest cross-sectional area of the oil drainage passage in a radial-direction cross-section thereof is on the anterior side in the rotational direction of the rotating shaft () with respect to a vertical plane P that passes though the center (O) of the rotating shaft (), and the largest cross-sectional area of the oil drainage passage in the radial-direction cross-section is on the posterior side in the rotational direction of the rotating shaft () with respect to the vertical plane that passes through the center (O) of the rotating shaft ().