An embodiment device includes an auxiliary brake including a retarder selectively operated to consume an output of a transmission to generate a braking force and an engine brake selectively operated to increase a flow resistance of an exhaust gas discharged from an engine to generate a braking force, a gas flow volume controller configured to open or close flow paths of an engine intake line and an engine exhaust line, and a controller configured to compare a first braking force difference with a predetermined reference braking force when the auxiliary brake is operated during coasting traveling and to determine and control an opening rate of the gas flow volume controller based on the first braking force difference and an engine speed when the first braking force difference is less than the reference braking force.

An embodiment device includes an auxiliary brake including a retarder selectively operated to consume an output of a transmission to generate a braking force and an engine brake selectively operated to increase a flow resistance of an exhaust gas discharged from an engine to generate a braking force, a gas flow volume controller configured to open or close flow paths of an engine intake line and an engine exhaust line, and a controller configured to compare a first braking force difference with a predetermined reference braking force when the auxiliary brake is operated during coasting traveling and to determine and control an opening rate of the gas flow volume controller based on the first braking force difference and an engine speed when the first braking force difference is less than the reference braking force.

In one aspect, a method for controlling an internal combustion engine system including an exhaust gas recirculation (EGR) valve and a variable-geometry turbocharger (VGT) having a compressor and a turbine includes receiving a plurality of requests for the internal combustion engine system. The method also includes predicting a plurality of expected states of the internal combustion engine system based on the plurality of requests and generating sets of candidate control points for actuating the EGR valve and the VGT based on the plurality of expected states. The method further includes selecting a set of candidate control points that avoids a surge condition of the compressor and based on the selected set of candidate control points, generating commands for actuating the EGR valve and the VGT.

In one aspect, a method for controlling an internal combustion engine system including an exhaust gas recirculation (EGR) valve and a variable-geometry turbocharger (VGT) having a compressor and a turbine includes receiving a plurality of requests for the internal combustion engine system. The method also includes predicting a plurality of expected states of the internal combustion engine system based on the plurality of requests and generating sets of candidate control points for actuating the EGR valve and the VGT based on the plurality of expected states. The method further includes selecting a set of candidate control points that avoids a surge condition of the compressor and based on the selected set of candidate control points, generating commands for actuating the EGR valve and the VGT.

A method for controlling a speed of a turbocharger that is in operative connection with a compressor, the steps including: provision of a setpoint for the speed of the turbocharger on the basis of a model-based precontrol for a calculation of a desired boost pressure ahead of the turbocharger; determination of an actual value for the speed of the turbocharger; control of an actuator of the turbocharger in order to compensate for the difference between the desired value and the actual value for the speed of the turbocharger. A main signal and a subsidiary signal are provided during the determination of the actual value for the speed of the turbocharger, wherein the main signal and the subsidiary signal are combined in order to validate the actual value for the speed of the turbocharger.

An exhaust gas turbocharger assembly includes a turbocharger, an actuator, and a bolted connection for releasably securing the actuator housing on a housing flange of the turbocharger housing. The bolted connection includes a through opening, an aperture bounded at the circumference by an internal thread made of a metal, and a fit bolt with a bolt body which merges axially into a bolt head. The bolt body has a first axial body section with an external thread formed in a manner complementary to the internal thread of the aperture, and a second axial body section arranged axially between the bolt head and the first body section. The fit bolt engages through the through opening of the actuator housing in the internal thread of the aperture with the external thread to clamp the actuator housing between the housing flange of the turbocharger housing and the bolt head of the fit bolt.

An exhaust gas turbocharger assembly includes a turbocharger, an actuator, and a bolted connection for releasably securing the actuator housing on a housing flange of the turbocharger housing. The bolted connection includes a through opening, an aperture bounded at the circumference by an internal thread made of a metal, and a fit bolt with a bolt body which merges axially into a bolt head. The bolt body has a first axial body section with an external thread formed in a manner complementary to the internal thread of the aperture, and a second axial body section arranged axially between the bolt head and the first body section. The fit bolt engages through the through opening of the actuator housing in the internal thread of the aperture with the external thread to clamp the actuator housing between the housing flange of the turbocharger housing and the bolt head of the fit bolt.

A control method for use in an engine braking maneuver for an internal combustion engine (ICE) system including a turbocharger having a variable-nozzle turbine (VNT), the ICE system further including an exhaust flap disposed in an exhaust line downstream of the variable-nozzle turbine. Prior to closing the exhaust flap, the VNT vanes are first parked in a fully open position. After the exhaust flap closes, the vanes are pivoted to a fully closed position and are continuously urged against a hard stop as long as the exhaust flap is closed. Termination of engine braking entails pivoting the vanes back to the fully open position, whereupon the exhaust flap is opened.

A control method for use in an engine braking maneuver for an internal combustion engine (ICE) system including a turbocharger having a variable-nozzle turbine (VNT), the ICE system further including an exhaust flap disposed in an exhaust line downstream of the variable-nozzle turbine. Prior to closing the exhaust flap, the VNT vanes are first parked in a fully open position. After the exhaust flap closes, the vanes are pivoted to a fully closed position and are continuously urged against a hard stop as long as the exhaust flap is closed. Termination of engine braking entails pivoting the vanes back to the fully open position, whereupon the exhaust flap is opened.

A turbocharger includes a first housing configured to house a turbine impeller, a second housing configured to rotatably support a rotating shaft to which the turbine impeller is fixed, and a variable capacity mechanism configured to surround the turbine impeller and to guide a fluid to the turbine impeller. The variable capacity mechanism has a nozzle ring that faces the second housing. A first pin and a second pin extend between the second housing and the nozzle ring and are attached to one of the second housing and the nozzle ring. The other of the second housing and the nozzle ring is provided with a first guide in which an end portion of the first pin is disposed and a second guide in which an end portion of the second pin is disposed.