TURBOCHARGER OUTBOARD PURGE SEAL

摘要

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.

主权项

1. A sealing system for the compressor end of a turbocharger comprising:
a rotating assembly including a shaft (20′) having axis of rotation (21′) and a compressor wheel (18′) mounted on the shaft (20′), the compressor wheel (18′) including a backface (38′); a bearing housing (23′), a portion of the shaft (20′) being received in the bearing housing (23′); one or more seals (32′) operatively positioned in an interface (400) between one or more static turbocharger elements and the rotating assembly, whereby the one or more seals (32′) minimize oil passage from the bearing housing across the interface (400); and a generally annular pressure plate (60, 81, 110) operatively positioned between the backface (38′) of the compressor wheel (18′) and the bearing housing (23′), a volume (80) being defined between at least the pressure plate (60, 81, 110) and the bearing housing (23′), the volume (80) having a restricted flow outlet passage (64, 86, 114), whereby the interface (400) is substantially isolated from the effects of a region behind the compressor wheel.