Bearing housing shroud
View Patent ↗A turbocharger including a turbine wheel having a hub-to-tip ratio of no more than 60% and blades with a high turning angle, a turbine housing forming an inwardly spiraling primary-scroll passageway that significantly converges to produce highly accelerated airflow into the turbine at high circumferential angles, and a two-sided parallel compressor. The compressor and turbine each produce substantially no axial force, allowing the use of minimal axial thrust bearings. The bearing housing forms a shroud for the internal side of the compressor wheel.
1. A turbocharger, comprising:
a turbocharger housing including a turbine housing, a bearing housing that is integral, and a compressor housing, wherein the turbine housing is axially connected to the bearing housing, and the bearing housing is axially connected to the compressor housing, and wherein the bearing housing houses bearings;
a rotor configured to rotate within the turbocharger housing along an axial axis of rotor rotation, the rotor including a turbine wheel, a two-sided compressor wheel, and a shaft extending along the axis of rotor rotation and connecting the turbine wheel to the compressor wheel, wherein the bearings constrain the rotor from movement other than axial rotation, and wherein the compressor wheel includes a first set of compressor blades facing axially away from the turbine wheel and a second set of compressor blades facing axially toward the turbine wheel;
wherein the compressor housing forms a first shroud wall that substantially conforms to a space through which the first set of compressor blades is configured to rotate, leaving only a small gap there-between; and
wherein the bearing housing forms a second shroud wall that substantially conforms to a space through which the second set of compressor blades is configured to rotate, leaving only a small gap there-between.
2. The turbocharger of claim 1 , wherein:
the bearing housing sequentially includes a turbine-end portion, a central portion, one or more supports, and a compressor-end portion;
the turbine-end portion and central portion forms structures that support the bearings;
the compressor end portion forms the second shroud wall; and
the one or more supports extend between the central portion and the compressor-end portion.
3. The turbocharger of claim 2 , wherein:
the one or more supports are a plurality of supports that are radially separated from and circumferentially spaced around the axis of rotor rotation; and
the plurality of supports form a plurality of radial openings into the bearing housing between the compressor-end portion and the central portion.
4. The turbocharger of claim 2 , wherein the central-portion of the bearing housing is affixed directly to the compressor housing.
5. The turbocharger of claim 1 , wherein:
the bearing housing sequentially includes a first portion, and a second portion;
the first portion forms a first wall of an inlet passage configured to pass inlet air to an inlet of the second set of compressor blades; and
the second portion forms a second wall of the inlet passage.
6. A bearing housing for use with the a rotatable two-sided compressor wheel of a turbocharger, the compressor wheel having a first set of blades and a second set of blades, comprising:
an integral body sequentially including a first-end portion, a central portion, one or more supports, and a second-end portion;
wherein the first-end portion and central portion forms structures configured to support bearings;
the second-end portion forms a shroud wall that substantially conforms to a space through which the second set of compressor blades is configured to rotate, leaving only a small gap there-between; and
the one or more supports extend between the central portion and the second-end portion.
7. The turbocharger of claim 6 , wherein:
the one or more supports are a plurality of supports that are radially separated from and circumferentially spaced around the axis of rotor rotation; and
the plurality of supports form a plurality of radial openings into the bearing housing between the compressor-end portion and the central portion.
8. The turbocharger of claim 7 , wherein the central portion forms a first wall of an inlet passage configured to pass inlet air to an inlet of the second set of compressor blades, and wherein the second-end portion forms a second wall of the inlet passage.