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.

A shut-off member for a turbocharger for an internal combustion engine includes a first channel, a second channel, and a wall that separates the first channel from the second channel. A shut-off member opening is formed in the wall that connects the first channel and the second channel. The shut-off member opening is selectively openable and closable by a shut-off member body. A cooling channel is disposed in the wall and at least partially surrounds the shut-off member opening.

A turbocharger engine includes a dual stage turbocharger in which a first turbo unit is disposed on the upstream side of a second turbo unit on an exhaust passage. The turbocharger is disposed in such a manner that a second turbine shaft of the second turbo unit is far from an engine output shaft than a first turbine shaft of the first turbo unit in a plan view in an axis direction of a cylinder. Further, a second turbine is rotated clockwise around an axis thereof in a side view when the turbocharger is viewed from the side of the turbine, and an intra-turbine passage is disposed on the side of an engine body than the second turbine shaft.

A vehicle with a turbocharged engine, including an engine body, an intake passage, an exhaust passage, a turbocharger, and a radiator. The radiator is provided with a cooling unit for cooling an engine coolant, and an upper tank into which the coolant is introduced after cooling the engine body. The turbocharger is provided with a turbine provided to the exhaust passage, a compressor provided to the intake passage, a coupling shaft coupling the turbine to the compressor, and bearings supporting the coupling shaft. The turbine is provided with an impeller for being rotated by introduced exhaust gas, and a turbine casing. The turbocharger is oil-cooled, and cooled by a lubricant. The turbine casing is formed from a sheet metal. The coupling shaft extends horizontally, and a height of an axial center of the shaft is above a height of an upper end of the upper tank of the radiator.

A shut-off member for a turbocharger for an internal combustion engine includes a first channel, a second channel, and a wall that separates the first channel from the second channel. A shut-off member opening is formed in the wall that connects the first channel and the second channel. The shut-off member opening is selectively openable and closable by a shut-off member body. A cooling channel is disposed in the wall and at least partially surrounds the shut-off member opening.

An engine system includes an intake passage, a non-deactivation exhaust passage, a second exhaust manifold, a first turbocharger including a first turbine rotated by exhaust gas flowing via the first exhaust manifold, a second turbocharger including a second turbine rotated by exhaust gas flowing via the second exhaust manifold, an exhaust outlet, a main intake circulation passage in communication with the intake passage via a compressor of the first turbocharger such that supercharging air is supplied to the intake passage, a sub intake circulation passage in communication with the main intake circulation passage via a compressor of the second turbocharger such that supercharging air is supplied to the main intake circulation passage, and a deactivation valve disposed on the sub intake circulation passage between the compressor of the second turbocharger and the main intake circulation passage so as to selectively open/close the sub intake circulation passage.

A supercharged internal combustion engine has cylinder groups with plural cylinders and plural exhaust gas turbochargers. Exhaust gas can be fed to at least one first exhaust gas turbocharger from first outlet valves of the cylinders of the first and second cylinder groups via at least one first exhaust manifold. Exhaust gas can be fed to at least one second exhaust gas turbocharger from second outlet valves of cylinders of the first and second cylinder groups via a second exhaust manifold. At low rotational speeds and/or in part load and/or non-steady state operation, exhaust gas can be fed via the first exhaust manifolds that are connected to the first outlet valves per cylinder group to a turbine of the first exhaust gas turbocharger in flows that can be divided in the inflow region of the turbine, while the second exhaust gas turbocharger is inactive.

An air boost system for a two-cycle engine, such as an EMD engine, which operates with a gear-driven turbo-supercharger. The turbo-supercharger is undersized for the engine, such that it is insufficient to provide air flow for a target air-fuel ratio above a pre-determined mid-load threshold. An additional turbocharger is installed in parallel with the turbo-supercharger, such that the intake manifold may receive air intake from only the turbo-supercharger or from both the turbo-supercharger and the turbocharger. In operation, the turbocharger is active only at loads above the predetermined load threshold.

A system and methods are described for a turbocharged engine, comprising powering the engine using a first operating cylinder, supplementing the power using a second switchable cylinder, deactivating the second switchable cylinder responsive to a load below a first threshold, and closing a first shut-off valve downstream of a compressor during the partial deactivation to prevent a first turbocharger from imparting a delivery action into a second compressor during the partial deactivation. Embodiments are further described wherein a bypass line in a second exhaust line further serves as a short-circuit line to prevent the second compressor from imparting a delivery action against the closed first shut-off valve. A variable valve timing is then included to further optimize the combustion process during the partial deactivation.

An exhaust casing for use with a turbocharger includes a hollow body that has two mutually opposed large walls, which extend along first and second major dimensions of the hollow body and are spaced apart by a minor dimension of the hollow body, the hollow body defining a plenum and an inlet nozzle opening into the plenum along the minor dimension of the hollow body. The casing further includes an outlet nozzle opening from the plenum along one of the major dimensions of the hollow body.