A supercharging system for an internal combustion engine controls an intake flow-passage switching valve and an exhaust flow-passage switching valve disposed in an intake flow passage and an exhaust flow passage, respectively, on the basis of a first control index which is calculated on the basis of a target boost pressure calculated on the basis of an operational state of the internal combustion engine and an actual boost pressure. The first control index is calculated from an arithmetic expression including opening degrees of the intake flow-passage switching valve and the exhaust flow-passage switching valve as variables.

A supercharging system for an internal combustion engine controls an intake flow-passage switching valve and an exhaust flow-passage switching valve disposed in an intake flow passage and an exhaust flow passage, respectively, on the basis of a first control index which is calculated on the basis of a target boost pressure calculated on the basis of an operational state of the internal combustion engine and an actual boost pressure. The first control index is calculated from an arithmetic expression including opening degrees of the intake flow-passage switching valve and the exhaust flow-passage switching valve as variables.

An aftercooler is provided comprising a housing, an outlet diverter coupled to the housing and having an outlet port, and an inlet diffuser comprising a forward wall having a peripheral rim coupled to the housing, an upper wall connected to the forward wall, a lower wall connected to the forward wall, a first side wall connected to the upper wall and the lower wall and having a first end disposed adjacent the peripheral rim and a second end disposed adjacent an inlet port of the inlet diffuser, a second side wall connected to the upper wall and the lower wall and having a first end disposed adjacent the peripheral rim and a second end disposed adjacent the inlet port, and a plurality of fins disposed within an interior volume of the inlet diffuser collectively distributing air across an outlet opening of the inlet diffuser for delivery to the housing.

A system is provided comprising an engine having a first cylinder bank and a second cylinder bank disposed in a VEE configuration, a first compressor configured to compress fluid to a first pressure, a first cooler coupled to the first compressor, the first cooler receiving the compressed fluid from the first compressor and cooling the compressed fluid, a second compressor coupled to the first cooler, the second compressor being configured to receive cooled, compressed fluid from the first cooler and compress the cooled, compressed fluid to a second pressure that is higher than the first pressure, and a second cooler coupled to the second compressor, the second cooler receiving the compressed fluid from the second compressor and cooling the compressed fluid for introduction into the pair of cylinder banks. The first compressor, the first cooler, the second compressor and the second cooler are disposed within the VEE.

A supercharging unit for an internal combustion engine has a high-pressure turbine which drives a high-pressure compressor so as to perform a rotational movement about a first axis and through which exhaust gas of the internal combustion engine flows, and having a low-pressure turbine which drives a low-pressure compressor so as to perform a rotational movement about a second axis and through which exhaust gas flows. The high-pressure turbine is arranged rotationally conjointly on a first shaft, and the high-pressure compressor is arranged rotationally conjointly on a second shaft, wherein the first and the second shaft are arranged parallel to one another and are arranged offset with respect to one another, wherein the first and the second shaft are mechanically operatively connected to one another such that the high-pressure compressor can be driven by the high-pressure turbine.

A supercharging unit for an internal combustion engine has a high-pressure turbine which drives a high-pressure compressor so as to perform a rotational movement about a first axis and through which exhaust gas of the internal combustion engine flows, and having a low-pressure turbine which drives a low-pressure compressor so as to perform a rotational movement about a second axis and through which exhaust gas flows. The high-pressure turbine is arranged rotationally conjointly on a first shaft, and the high-pressure compressor is arranged rotationally conjointly on a second shaft, wherein the first and the second shaft are arranged parallel to one another and are arranged offset with respect to one another, wherein the first and the second shaft are mechanically operatively connected to one another such that the high-pressure compressor can be driven by the high-pressure turbine.

A multi-stage turbocharging assembly is described. The multi-stage turbocharging assembly includes a high-pressure stage including a high-pressure turbine coupled with a high-pressure compressor. Additionally, the multi-stage turbocharging assembly includes a low-pressure stage including a low-pressure turbine coupled with a low-pressure compressor: Further, the multi-stage turbocharging assembly includes a casing enclosing the high-pressure stage and the low-pressure stage, wherein the casing is a single unit.

A multi-stage turbocharging assembly is described. The multi-stage turbocharging assembly includes a high-pressure stage including a high-pressure turbine coupled with a high-pressure compressor. Additionally, the multi-stage turbocharging assembly includes a low-pressure stage including a low-pressure turbine coupled with a low-pressure compressor: Further, the multi-stage turbocharging assembly includes a casing enclosing the high-pressure stage and the low-pressure stage, wherein the casing is a single unit.

A turbocharger engine includes an engine body and a turbocharger. The turbocharger includes a large turbo unit having a large turbine chamber, a large compressor chamber, and a large turbine shaft extending between the two chambers; and a small turbo unit having a small turbine chamber, a small compressor chamber, and a small turbine shaft extending between the two chambers. The large compressor chamber is disposed upstream of the small compressor chamber in an intake passage. A large turbo axis and a small turbo axis are disposed to extend generally in the same direction as an engine output axis. The large turbo unit is disposed such that the large turbo axis is non parallel to the engine output axis, and a large-compressor-chamber-side portion of the large turbo axis is closer to the engine output axis than a large-turbine-chamber-side portion thereof in a plan view in an axis direction of the cylinder.

A turbocharger engine includes an engine body and a turbocharger. The turbocharger includes a large turbo unit having a large turbine chamber, a large compressor chamber, and a large turbine shaft extending between the two chambers; and a small turbo unit having a small turbine chamber, a small compressor chamber, and a small turbine shaft extending between the two chambers. The large compressor chamber is disposed upstream of the small compressor chamber in an intake passage. A large turbo axis and a small turbo axis are disposed to extend generally in the same direction as an engine output axis. The large turbo unit is disposed such that the large turbo axis is non parallel to the engine output axis, and a large-compressor-chamber-side portion of the large turbo axis is closer to the engine output axis than a large-turbine-chamber-side portion thereof in a plan view in an axis direction of the cylinder.