Abstract: A turbocharger rotating assembly (125) includes a shaft (20) rotatably supported in a bearing housing (123) via bearings (26, 128), a compressor impeller (18) mounted on the shaft (20), and an oil flinger (122) disposed on the shaft (20) between the bearings (26, 128) and the compressor impeller (18). The turbocharger (100) further includes an insert (134) disposed in the shaft-receiving axial bore (120) so as to surround the oil flinger (122), and a purge seal (160) operatively positioned in an interface (131) between the insert (134) and the oil flinger (122), whereby the purge seal (160) is configured to minimize oil passage from the bearing housing (123) into the interface (131). An annular cavity (150) encircles the radially outward-facing surface (138) of the insert (134), the cavity (150) forming a portion of a fluid path configured to deliver pressurized fluid to the interface (131).

Abstract: A turbocharger rotating assembly (125) includes a shaft (20) rotatably supported in a bearing housing (123) via bearings (26, 128), a compressor impeller (18) mounted on the shaft (20), and an oil flinger (122) disposed on the shaft (20) between the bearings (26, 128) and the compressor impeller (18). The turbocharger (100) further includes an insert (134) disposed in the shaft-receiving axial bore (120) so as to surround the oil flinger (122), and a purge seal (160) operatively positioned in an interface (131) between the insert (134) and the oil flinger (122), whereby the purge seal (160) is configured to minimize oil passage from the bearing housing (123) into the interface (131). An annular cavity (150) encircles the radially outward-facing surface (138) of the insert (134), the cavity (150) forming a portion of a fluid path configured to deliver pressurized fluid to the interface (131).

Abstract: The propensity for oil leakage around the clearance seals of a rotating turbocharger assembly can be minimized by the addition of a variety of sealing systems using an externally pressurized cavity formed between the backface of the compressor wheel and the bearing housing. In one implementation, a pressure plate can be provided. In another embodiment, labyrinth seals can be provided. In addition to these various sealing arrangements, external pressurized air or internally supplied charge air can be selectively supplied to the space behind the pressure plate or labyrinth seal to maintain an inward directed pressure gradient across the seal interface regardless of operating conditions.