Patent ID: 8474433

Claim:
An engine braking method for an internal combustion engine having an air intake path and an exhaust gas path, a turbocharger comprising a turbine in the exhaust gas path and a compressor in the intake path, the turbine comprising a turbine wheel rotatably disposed in a turbine housing, the compressor comprising a compressor impeller rotatably disposed in a compressor housing, the turbine wheel and compressor impeller being connected by a turbocharger shaft, a bearing housing disposed between the compressor and turbine for housing a bearing assembly to support the turbocharger shaft in rotation, at least one first seal between a compressor end of the shaft and the bearing housing, the method comprising: operating the engine in an engine braking mode by activating an exhaust gas brake to impede the flow of exhaust gas in the exhaust gas path when the engine throttle is closed, thereby generating an exhaust gas back-pressure in the exhaust gas path; diverting at least a portion of the exhaust gas during engine braking mode from the exhaust gas path in order to increase the pressure gradient across the at least one first seal in the direction from the bearing housing to the compressor housing.