A valve device for exhaust gas recirculation in the exhaust gas system of a motor vehicle that is driven by an internal combustion engine. In order to create a valve device that can be used as an EGR check valve in which a pressure loss relative to known designs is reduced even with small valve geometries, it is proposed for the valve device to comprise a valve body that is embodied as a separate part that is mushroom-shaped or umbrella-shaped and is axially guided in a supporting plate in a region through which the gas flows axial, rests with its umbrella against the supporting plate in a way that seals the region through which the gas flows in a closed position, and has an end stop for an open position.

In accordance with one aspect of the present disclosure, a turbocharger includes a compressor having a compressor wheel, a turbine provided within a housing, and an exhaust gas recirculation (EGR) flow path. The EGR flow path includes a first fluid connection in the housing and located in proximity to the turbine, a second fluid connection located in proximity to a trailing edge of the compressor wheel, an EGR control valve disposed between the first fluid connection and the second fluid connection, the EGR control valve configured to selectively operate the turbocharger in a low-heat mode having an EGR up to 50% and an operational mode having an EGR rate typically less than 35%.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

A hot gas exhaust recirculation valve includes a housing containing a duct for conducting gases, a drive chamber, and a valve stem which is mounted in the housing. The valve stem can be displaced in its longitudinal direction thereof and extends from the drive chamber into the duct. The end of the valve stem that is situated in the drive chamber is coupleable to a drive device. A closing body is fastened to the other end of the valve stem. The closing body is situated in the duct and has a closed position in which it separates an upstream section of the duct from a downstream section of the duct. A sealing ring surrounds the valve stem and is arranged between the duct and the drive chamber. The valve stem is supported within two bearing bushings that are spaced apart from each other, between which the sealing ring is arranged.

A hot gas exhaust recirculation valve includes a housing containing a duct for conducting gases, a drive chamber, and a valve stem which is mounted in the housing. The valve stem can be displaced in its longitudinal direction thereof and extends from the drive chamber into the duct. The end of the valve stem that is situated in the drive chamber is coupleable to a drive device. A closing body is fastened to the other end of the valve stem. The closing body is situated in the duct and has a closed position in which it separates an upstream section of the duct from a downstream section of the duct. A sealing ring surrounds the valve stem and is arranged between the duct and the drive chamber. The valve stem is supported within two bearing bushings that are spaced apart from each other, between which the sealing ring is arranged.

Provided is a resin bush capable of slidably supporting a shaft when the bush has been fitted in a housing; particularly, a resin bush suitable for use in an environment in which the effects of a difference in thermal expansion coefficients are likely to be prominent, such as a high-temperature environment, even when the housing and the shaft are made of a material such as a metal that has a different thermal expansion coefficient from that of the resin bush. In the resin bush (1), which is molded by extrusion molding, a slit (12) is formed from one axial end surface (11a) towards another axial end surface (11b). A recessed section (13) for a gate (a gate position), which is provided to the one axial end surface (11a), is provided in a position that is deviated from being symmetrical with the slit (12), at least with respect to a center axis O of a bush body (10). The resin used for the material of the bush (1) is a resin having excellent heat resistance and chemical resistance, such as PPS resin or a PEEK resin.

Provided is a resin bush capable of slidably supporting a shaft when the bush has been fitted in a housing; particularly, a resin bush suitable for use in an environment in which the effects of a difference in thermal expansion coefficients are likely to be prominent, such as a high-temperature environment, even when the housing and the shaft are made of a material such as a metal that has a different thermal expansion coefficient from that of the resin bush. In the resin bush (1), which is molded by extrusion molding, a slit (12) is formed from one axial end surface (11a) towards another axial end surface (11b). A recessed section (13) for a gate (a gate position), which is provided to the one axial end surface (11a), is provided in a position that is deviated from being symmetrical with the slit (12), at least with respect to a center axis O of a bush body (10). The resin used for the material of the bush (1) is a resin having excellent heat resistance and chemical resistance, such as PPS resin or a PEEK resin.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.