Abstract: A turbocharger includes a foil bearing assembly mounted in a center housing between a compressor and a turbine of the turbocharger. The bearing assembly forms a unit installable into the center housing from one end thereof, and the center housing is a one-piece construction. The bearing assembly includes a foil thrust bearing assembly disposed between two foil journal bearings. The journals foils are mounted in annular bearing carriers fixedly mounted in the center housing. A radially inner portion of a thrust disk of the thrust bearing assembly is captured between a shaft and a shaft sleeve of the turbocharger. The center housing defines cooling air passages for supplying cooling air to the foil bearings, and optionally includes a water jacket for circulating engine coolant through the center housing.

Abstract: A compressor impeller for use with a boreless turbocharger is provided in accordance with this invention. The compressor impeller comprises an integral hub projecting axially therefrom that includes a partial bore therein that extends from an open to a close bore end. The bore includes a threaded portion that is configured to accommodate threaded engagement with an end of a common shaft disposed through a turbocharger housing and attached at an opposite end to a turbine wheel. The hub is specially configured so that the threaded portion has a relatively increased wall thickness when compared to a remaining portion of the bore disposed between the threaded portion and the end of the bore. The bore is configured providing a section having a reduced wall thickness, between the threaded portion and the bore closed end, for purposes of providing a preferential stress relief mechanism.

Abstract: A buffer chamber and outlet guide provide an air path from an intake passage in a compressor housing to an upstream position relative to an intake port of the compressor. Surging is minimized during low airflow conditions while cyclic forces on the blades of the impeller are minimized during high airflow conditions. By providing an air path through the buffer chamber and outlet guide, ribs or other supporting structures are eliminated within the air pathway through the intake port and intake passage within the compressor housing.

Abstract: A buffer chamber and outlet guide provide an air path from an intake passage in a compressor housing to an upstream position relative to an intake port of the compressor. Surging is minimized during low airflow conditions while cyclic forces on the blades of the impeller are minimized during high airflow conditions. By providing an air path through the buffer chamber and outlet guide, ribs or other supporting structures are eliminated within the air pathway through the intake port and intake passage within the compressor housing.

Abstract: A compressor impeller for use with a boreless turbocharger is provided in accordance with this invention. The compressor impeller comprises an integral hub projecting axially therefrom that includes a partial bore therein that extends from an open to a close bore end. The bore includes a threaded portion that is configured to accommodate threaded engagement with an end of a common shaft disposed through a turbocharger housing and attached at an opposite end to a turbine wheel. The hub is specially configured so that the threaded portion has a relatively increased wall thickness when compared to a remaining portion of the bore disposed between the threaded portion and the end of the bore. The bore is configured providing a section having a reduced wall thickness, between the threaded portion and the bore closed end, for purposes of providing a preferential stress relief mechanism.

Abstract: A turbocharger having an electric motor for assisting spin up of the rotor employs a shaft carrying the turbine and compressor impeller with a unitary pinned semi-floating bearing supporting the shaft and a spacer collar carrying the electric motor magnet. The unitary bearing has integral thrust faces engaging a hub of the turbine wheel and the spacer collar. A reduced diameter of the shaft received in the spacer collar allows the collar to engage a greater diameter bearing land allowing the attachment of the compressor impeller with a nut on the shaft extending through a bore in the impeller to firmly engage the impeller, spacer collar and bearing land of the shaft to fix the rotor length. The pinned semi-floating bearing with integral thrust faces provides enhanced reaction moments for negative spring forces created by the electric motor in operation and the additional length of the rotor created by the motor.

Abstract: Lubricating oil leakage in a turbocharger is reduced through the use of a gland seal having multiple channels in the gland face formed by ribs extending radially in a spiral or herringbone pattern for enhanced maximum pumping effect and minimized hoop stress related fatigue failures.

Abstract: Turbocharger fatigue life monitors comprise at least one sensor that measures an actual operating condition of the turbocharger, e.g., turbine rotational speed or turbine inlet temperature. The device comprises a central processing unit for receiving information from each sensor and processing the information, using programs and predetermined turbocharger information, e.g., turbocharger material and stress data stored in one or more storage device in communication with the central processing unit, to provide an actual probability of turbocharger failure. The central processing unit compares the calculated probability of turbocharger failure to a predetermined specified probability of turbocharger failure stored in a storage device to determine whether turbocharger service is needed.

Abstract: An annular vane diffuser is disposed within a compressor housing of a turbocharger and employs a wave-type compression spring interposed between the vane diffuser and a backplate to provide a desired pressure loading on the vane diffuser to urge the vanes against the wall of the compressor housing forming one side of the diffuser. The vane diffuser constructed in this manner maintains contact with the compressor housing during turbocharger operation as it moves axially relative to the backplate, thereby providing improved diffuser efficiency.