A turbo compressor of an exhaust gas recirculation of an internal combustion engine, with a compressor housing, a compressor rotor, a shaft that is coupled to the compressor rotor and mounted in the compressor housing, a piston ring seal to prevent an exhaust gas blow-by flow in the direction of bearings, and a labyrinth seal, which seen in the direction of the exhaust gas blow-by flow, is positioned upstream of the piston ring seal.

A rotating group for a supercharger includes a driving shaft and rotor assembly including a driving shaft connected to a driving rotor. A driven shaft and rotor assembly include a driven shaft connected to a driven rotor. The driving rotor is in intermeshing engagement with the driven rotor to rotate in a pair of transversely overlapping cylindrical chambers defined in a rotor housing of the supercharger. A driving shaft bearing is disposed in a bottom plate to radially and axially support the driving shaft for rotating the driving rotor in the rotor housing at a first predetermined axial location of the driving rotor from the bottom plate. A driven shaft bearing is disposed in the bottom plate to radially and axially support the driven shaft for rotating the driven rotor in the rotor housing at a second predetermined axial location of the driven rotor from the bottom plate.

A supercharging device for an engine is provided, which includes a supercharger provided to an intake passage of the engine, an actuator configured to drive the supercharger, and a controller including a processor configured to control the actuator to drive the supercharger when an operating state of the engine is in a given supercharging range, and to stop the supercharger when the operating state is in a non-supercharging range. The controller causes the actuator to forcibly drive the supercharger in the non-supercharging range when a temperature of the supercharger is lower than a preset temperature, and prohibits the forcible drive of the supercharger when a rotation speed of the supercharger during the forcible drive of the supercharger is lower than a preset rotation speed.

A supercharging device for an engine is provided, which includes a supercharger provided to an intake passage of the engine, an actuator configured to drive the supercharger, and a controller including a processor configured to control the actuator to drive the supercharger when an operating state of the engine is in a given supercharging range, and to stop the supercharger when the operating state is in a non-supercharging range. The controller estimates an amount of condensate accumulated in an oil pan, and the controller causes the actuator to forcibly drive the supercharger when the estimated amount of condensate is more than a preset amount, even if the operating state is in the non-supercharging range.

An engine includes a variable compression-ratio mechanism adapted to change a compression ratio of an engine and a supercharger adapted to supply a compressed air to the engine. An engine control device that controls the engine controls the variable compression-ratio mechanism by setting target compression ratio such that the higher responsiveness of a supercharging pressure rise by the supercharger is, the lower the target compression ratio is.

A control apparatus for an internal combustion engine with a supercharger includes a boost-pressure detector. When first boost pressure control to control the supercharger such that a boost pressure reaches a target pressure starts, starts, the target pressure is set to an initial target pressure, gradually at a first rate, and then gradually increased to a steady-state target boost pressure at a second rate smaller than the first rate if the boost pressure is equal to or higher than a threshold pressure. Second boost pressure control is performed such that the boost pressure reaches a steady-state target boost pressure. Inhibiting/allowing circuitry is configured to inhibit execution of the first boost pressure control and allow execution of the second boost pressure control if the boost pressure is lower than the steady-state target boost pressure and if the steady-state target boost pressure is lower than the threshold pressure.

An engine includes a variable compression-ratio mechanism adapted to change a compression ratio of an engine and a supercharger adapted to supply a compressed air to the engine. An engine control device that controls the engine controls the variable compression-ratio mechanism by setting target compression ratio such that the higher responsiveness of a supercharging pressure rise by the supercharger is, the lower the target compression ratio is.

A method of controlling an engine system equipped with a supercharger may include determining a target value of boost pressure, depending on an rpm of an engine and then determining whether the supercharger is in an operable region, deducing a target rpm of the supercharger, based on a reference value previously input into the controller and a current state value of a vehicle input into the controller, when it has been determined in the operating-region determination that the supercharger is in the operable region, setting a maximum value, in the target rpm deduced in the target-rpm deduction, to a drive rpm of the supercharger, and verifying whether the set drive rpm is greater than or equal to a predetermined reference value previously input into the controller, and driving the supercharger at the set drive rpm, by closing the bypass valve to open the supercharger path.

A supercharged internal combustion engine has a supercharger operable to selectively supply a mass of air from below through above atmospheric air pressure according to the operating requirements of the engine. The supercharger has a shuttle combined with a throttle valve that controls the mass of air directed to an air mass bypass opening and supplied to the internal combustion engine. The shuttle has rollers that ride on rails that allow the shuttle to move to open and close the air mass bypass opening in communication with a casing that directs a mass of atmospheric air and a bypass mass of air interfused with the mass of atmospheric air to an air mass inlet of the supercharger.

For example, during an acceleration transient period of time during which a demand load is raised, a supercharging pressure is raised before a mechanical compression ratio is lowered and an internal combustion engine falls in a high load state. At this time, there is a possibility that a generation of knocking and an excessive rise in a cylinder inner pressure occur. This possibility is a task to be solved. The internal combustion engine includes: a variable compression ratio mechanism which is capable of modifying the mechanical compression ratio; a turbo charger (2) which supercharges intake air utilizing an exhaust energy; and an exhaust bypass valve (7) which adjusts a supercharging pressure as a supercharging pressure adjustment mechanism. The mechanical compression ratio is detected by a control shaft sensor (34) and the supercharging pressure is limited on a basis of this mechanical compression ratio.