Abstract: An oil-drain device for a thrust bearing includes: a rotor shaft; a collar member mounted to an outer periphery of the rotor shaft; a thrust bearing supporting the rotor shaft in an axial direction; and an oil-drain space forming member defining an oil-drain space through which lubricant oil leaking from a sliding portion of the thrust bearing flows, between the thrust bearing and the oil-drain space forming member. The oil-drain space includes: an oil-drain channel defined between a first end surface of the thrust bearing and a first end surface of the oil-drain space forming member, surrounding the flange portion of the collar member; and an oil-drain port formed below the oil-drain channel, for discharging the lubricant oil flowing through the oil-drain channel outside the oil-drain space.

Abstract: A rotary machine is provided with: a flange section protruding in the radial direction of a rotating shaft which rotates about an axis and rotating together with the rotating shaft; a stationary bush disposed at a distance in the direction of the axis from the flange section, surrounding the outer peripheral surface of the rotating shaft, and provided in a housing supporting the rotating shaft so as to be immovable in the direction of the axis relative to the rotating shaft; and a rotation bush which is disposed between the flange section and the stationary bush so as to be sandwiched there between in the direction of the axis, covers the outer peripheral surface of the rotating shaft, and is rotatable relative to the rotating shaft and the housing while floating in fluid. The rotation bush has, on the surface thereof which faces the direction of the axis, a land surface and a tapered surface which is continuous with the land surface.

Abstract: An object is to provide a floating bush bearing device including a circumferential groove over the entire circumference of an outer peripheral surface of a floating bush while ensuring that a pressing force is applied by lubricant oil to the floating bush to reduce oscillation, as well as a turbocharger provided with the bearing device.