Abstract: A turbocharger (10) with a heat shield (60) positioned between the turbine wheel (30) and the bearing housing (20), wherein the heat shield defines a gap (70) between the turbine wheel (30). The heat shield (60) and is provided with at least one rib (80) extending into the gap. In this gap, in the case of a conventional flat heat shield, the turbine wheel backface may act in the manner of a centrifugal pumping, pumping gas out from within the gap, creating a region of reduced pressure adjacent the outboard side of the turbine shaft bearing, drawing oil out the shaft bearing and into the space between the turbine wheel backface and the heat shield. The inventive heat shield has raised structures designed to interfere with the rotational and centrifugal flow of gas in the gap between heat shield and turbine wheel backface, thus prevent oil bypass.

Abstract: A turbocharger (10) with a heat shield (60) positioned between the turbine wheel (30) and the bearing housing (20), wherein the heat shield defines a gap (70) between the turbine wheel (30). The heat shield (60) and is provided with at least one rib (80) extending into the gap. In this gap, in the case of a conventional flat heat shield, the turbine wheel backface may act in the manner of a centrifugal pumping, pumping gas out from within the gap, creating a region of reduced pressure adjacent the outboard side of the turbine shaft bearing, drawing oil out the shaft bearing and into the space between the turbine wheel backface and the heat shield. The inventive heat shield has raised structures designed to interfere with the rotational and centrifugal flow of gas in the gap between heat shield and turbine wheel backface, thus prevent oil bypass.