A bearing device for a turbocharger according to one embodiment of the present invention includes: a rotational shaft; a journal bearing device including a compressor-side journal bearing and a turbine-side journal bearing; a bearing housing including a compressor-side bearing supporting portion, a turbine-side bearing supporting portion, and a bearing housing main body; and a lubricant oil guide member extending along a circumference direction of the rotational shaft, at an outer circumference side of at least one of the compressor-side bearing supporting portion and the turbine-side bearing supporting portion. When a virtual line extending vertically downward from a rotational center CL of the rotational shaft is defined as a reference line VL in a state where an oil discharge port is orientated downward, the lubricant oil guide member extends from the reference line VL along the circumference direction toward each of one side and another side of the reference line VL over a predetermined angle θ about the rotational center CL of the rotational shaft.

A turbocharger according to an embodiment of the present invention includes a rotating shaft, a compressor, a turbine, a compressor-side floating bearing and a turbine-side floating bearing that rotatably support the rotating shaft, and a bearing housing that houses the compressor-side floating bearing and the turbine-side floating bearing, the bearing housing being internally provided with a turbine-side oil feeding passage through which oil to be fed to the turbine-side floating bearing flows and a compressor-side oil feeding passage through which oil to be fed to the compressor-side floating bearing flows. A ratio of an oil feeding pressure for oil at an outlet of the compressor-side oil feeding passage to an oil feeding pressure for oil at an outlet of the turbine-side oil feeding passage is configured to be higher than 1.0 and lower than 1.5.

A copper-zinc alloy contains 59.0 to 65.0% Cu, 2.5 to 4.0% Mn, 1.2 to 2.5% Al, 0.5 to 2.0% Si, 0.2 to 1.0% Fe, 0 to 1.0% Pb, 0 to 1.5% Ni, 0 to 0.2% Sn, balance Zn and unavoidable impurities. The zinc alloy has excellent temperature resistance and surfaces produced by machining have a considerably reduced surface roughness.

A leak resistant compliant bushing includes a body having a first end, a second end, an outer surface and an inner surface defining a passage. The outer surface and the inner surface extending between the first end and the second end and define an axial axis. A first plurality of channels extends into the body from the first end. Each of the first plurality of channels includes a terminal end that is spaced from the second end. A second plurality of channels extend into the body from the second end. Each of the second plurality of channels extend between adjacent ones of the first plurality of channels and include a terminal end section that is spaced from the first end.

A bearing assembly for a charging apparatus. The bearing assembly comprises a bearing housing and a shaft. The bearing assembly further comprises a compressor-side bearing bushing and a turbine-side bearing bushing which together support the shaft inside a bearing bore of the bearing housing. The compressor-side bearing bushing is configured differently than the turbine-side bearing bushing.

A bearing element includes an inner surface (54) configured to receive a cylindrical shaft (18). The inner surface (54) includes a smooth profile having a plurality of sections (502). Each section (502) having a taper portion (506) between a first arc-span point (512) and a second arc-span point (514), a constant-radius portion (508) between the second arc-span point (514) and a third arc-span point (516), and a transition portion (510) between the third arc-span point (516) and a fourth arc-span point (518). An inner-surface radius dimension (520) changes from an inner-diameter major dimension to an inner-diameter minor dimension at the taper portion (506) and back at the transition portion.

A bearing element includes an inner surface (54) configured to receive a cylindrical shaft (18). The inner surface (54) includes a smooth profile having a plurality of sections (502). Each section (502) having a taper portion (506) between a first arc-span point (512) and a second arc-span point (514), a constant-radius portion (508) between the second arc-span point (514) and a third arc-span point (516), and a transition portion (510) between the third arc-span point (516) and a fourth arc-span point (518). An inner-surface radius dimension (520) changes from an inner-diameter major dimension to an inner-diameter minor dimension at the taper portion (506) and back at the transition portion.

The invention relates to a bearing unit for a turbocharger rotor. The bearing unit comprises a bearing housing and a bearing bush which is arranged in a central bore for radially mounting a turbocharger rotor in the bearing housing. In the region of a first axial end, the bearing bush has a radially outwardly extending projection. The projection is designed to interact with the bearing housing as an anti-rotation safeguard for the bearing bush.

The invention relates to a bearing unit for a turbocharger rotor. The bearing unit comprises a bearing housing and a bearing bush which is arranged in a central bore for radially mounting a turbocharger rotor in the bearing housing. In the region of a first axial end, the bearing bush has a radially outwardly extending projection. The projection is designed to interact with the bearing housing as an anti-rotation safeguard for the bearing bush.

A semi-floating bearing (multilobe bearing) including: an annular main body through which a shaft is inserted; and a radial bearing surface formed on an inner peripheral surface of the main body, the radial bearing surface including a plurality of arc surfaces having different curvature centers and disposed adjacent to each other in a circumferential direction of the main body, and a minimum distance Ra between a central axis of the shaft and the arc surface, a curvature radius Rb of the arc surface, and a radius Rs of the shaft satisfying relationships expressed by the following Formulas (1) and (2). Ra/Rs≥1.001 . . . (1), (Rb−Ra)/0.9≤(Rb−Rs)≤(Rb−Ra)/0.6 . . . (2) provided that Ra is the minimum distance between the central axis of the shaft and the arc surface, Rb is the curvature radius of the arc surface, and Rs is the radius of the shaft.