RETRACTABLE VANE DIFFUSER FOR COMPRESSORS

摘要

A retractable vane diffuser system (36) for a compressor stage (12) of a turbocharger with selectively retractable vanes (38). The retractable vane diffuser system (36) includes a retractable vane (38) or a set of vanes (40) that can extend into a flow path (34) of a diffuser (18) to help control airflow and change the operating characteristics of the compressor stage (12), such as improving surge margin or improving peak stage efficiency. The vanes (38) can retract preferably with a vane ring (44) into a cavity (42) of a wall (30 or 32) of the diffuser (18) when operation as a vaneless diffuser is desired to maximize flow, such as to slow onset of diffuser stall or surge. The retractable vane diffuser system (36) combines superior pressure ratio, efficiency, and lower mass air flow operating characteristics of a diffuser having vanes with higher mass airflow capacity of a vaneless diffuser.

主权项

1. A turbocharger having a compressor impeller (14) and a turbine wheel connected by a rotating shaft, the improvement comprising a retractable vane diffuser system (36) including:
a diffuser (18) defined by a hub wall (30) and a shroud wall (32) forming a flow path (34) for air as it leaves the compressor impeller (14); and a vane (38) retractable into the hub wall (30) or the shroud wall (32).