A recirculation system for a power system is disclosed. The recirculation system may determine, according to a sequence for individually activating a plurality of turbochargers of an engine, that a designated turbocharger of the plurality of turbochargers is to be activated. The recirculation system may cause a recirculation valve of a recirculation line to open to increase an airflow between an intake manifold and a compressor of the designated turbocharger.

Compressors and methods for operating compressors are provided. In one example, a compressor is provided that comprises a ported shroud including a first port positioned upstream of a leading side of a rotor and a second port positioned downstream of the leading side of the rotor. The compressor also includes a muffler arranged in the ported shroud and comprising a plurality of projections, each of the plurality of projections radially extend from a base of the muffler and include an aperture extending through the base.

Compressors and methods for operating compressors are provided. In one example, a compressor is provided that comprises a ported shroud including a first port positioned upstream of a leading side of a rotor and a second port positioned downstream of the leading side of the rotor. The compressor also includes a muffler arranged in the ported shroud and comprising a plurality of projections, each of the plurality of projections radially extend from a base of the muffler and include an aperture extending through the base.

A centrifugal compressor according to an embodiment includes a compressor impeller, a compressor housing, a suction-surface-side member disposed on a suction surface side of the compressor impeller, and a piezoelectric vibrator disposed in at least one of the compressor housing or the suction-surface-side member. The compressor housing and the suction-surface-side member have wall surfaces defining a space surrounded by the compressor housing and the suction-surface-side member. The wall surface of the at least one of the compressor housing or the suction-surface-side member is at least partially vibratable by operation of the piezoelectric vibrator.

A centrifugal compressor according to an embodiment includes a compressor impeller, a compressor housing, a suction-surface-side member disposed on a suction surface side of the compressor impeller, and a piezoelectric vibrator disposed in at least one of the compressor housing or the suction-surface-side member. The compressor housing and the suction-surface-side member have wall surfaces defining a space surrounded by the compressor housing and the suction-surface-side member. The wall surface of the at least one of the compressor housing or the suction-surface-side member is at least partially vibratable by operation of the piezoelectric vibrator.

A cylinder head assembly for an internal combustion engine includes a cast cylinder head having at least one oil gallery, a turbocharger housing integrally cast with the cylinder head, and a turbocharger cartridge assembly configured to be inserted into the turbocharger housing and including at least one bearing rotatably supporting a shaft coupled between a compressor wheel and a turbine wheel. A lubricant supply system having a lubricant passage formed within the turbocharger housing is configured to supply oil from the at least one oil gallery to the turbocharger cartridge assembly to lubricate the at least one bearing.

A cylinder head assembly for an internal combustion engine includes a cast cylinder head having at least one oil gallery, a turbocharger housing integrally cast with the cylinder head, and a turbocharger cartridge assembly configured to be inserted into the turbocharger housing and including at least one bearing rotatably supporting a shaft coupled between a compressor wheel and a turbine wheel. A lubricant supply system having a lubricant passage formed within the turbocharger housing is configured to supply oil from the at least one oil gallery to the turbocharger cartridge assembly to lubricate the at least one bearing.

The present invention includes: a turbine wheel 24 that is attached to a rotating shaft 14 and that has a plurality of turbine blades in the circumferential direction; scroll passages 15Aa, 15Ab that are formed in a spiral shape on the outside of the turbine wheel 24, and that are formed by being divided into a plurality of sections in the circumferential direction, the passages communicating with each other at the position of the turbine wheel 24 disposed between respective tongue sections 15Ac, 15Ad; and threads 51 that are provided on an back facing surface 41 disposed so as to oppose the back surface of the turbine wheel 24, the back surface being on the axially opposite side from the turbine blade side, and the linear parts extending from starting points 51a near the tongue sections 15Ac, 15Ad toward the rotating shaft 14 side so as to control the passage of fluid between the back surface and the back facing surface 41.

The present invention includes: a turbine wheel 24 that is attached to a rotating shaft 14 and that has a plurality of turbine blades in the circumferential direction; scroll passages 15Aa, 15Ab that are formed in a spiral shape on the outside of the turbine wheel 24, and that are formed by being divided into a plurality of sections in the circumferential direction, the passages communicating with each other at the position of the turbine wheel 24 disposed between respective tongue sections 15Ac, 15Ad; and threads 51 that are provided on an back facing surface 41 disposed so as to oppose the back surface of the turbine wheel 24, the back surface being on the axially opposite side from the turbine blade side, and the linear parts extending from starting points 51a near the tongue sections 15Ac, 15Ad toward the rotating shaft 14 side so as to control the passage of fluid between the back surface and the back facing surface 41.

An engine assembly including an internal combustion engine configured to be received in an engine compartment and a heat exchanger having a first conduit fluidly connected to a fluid circuitry of the engine and a second conduit fluidly connecting an interior of the engine compartment to its environment. The first conduit is in heat exchange relationship with the second conduit. The assembly further includes a forced air system operable in use to provide an air flow from the environment to the outlet via the second conduit of the heat exchanger and the engine compartment. The assembly further includes a selector valve configurable to selectively fluidly connect an air intake of the internal combustion engine with the interior of the engine compartment in a first valve position and with the environment in a second valve position. A method for supplying air to an internal combustion engine is also discussed.