Abstract: A compressor wheel (10) for a turbocharger having a prestressed hub (16) with an interference fit insert sized to provide the predetermined stress at zero rotational speed. The predetermined prestress then results in a reduced operating stress level during high speed rotation of the wheel, reducing the potential for reaching failure level stresses in operation and increasing wheel life.

Abstract: The present invention is embodied in a heat exchanger, which allows differential thermal expansion of its elements while providing a bypass seal. In at least one embodiment, the heat exchanger includes, a shell for containing a first gas, a core positioned within the shell, and a seal positioned between the core and the shell. The seal allows at least some differential expansion between the shell and the core while restricting the flow of the first gas past the seal. This allows a space for expansion of the core to exist between the core and the shell, while preventing the first gas from bypassing the core by traveling through the expansion space. As such, the seal forces the first gas to pass through the core, greatly increasing heat transfer from the first gas to the core. Preferably, the seal is mounted to the core at a position at least adjacent to the free (moveable) end or ends of the core. The seal can be folded into several layers such that the folds abut both the core and the shell.

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: An Exhaust Gas Recirulation (EGR) valve is integrated onto a turbocharger by providing an EGR outlet in a flange in the volute of the turbine housing and a mating valve assembly extending from a mating flange with an elbow. The outlet direction of the elbow is adjustable to a plurality of directions by positioning the mating flange relative to the EGR outlet flange.

Abstract: An enhanced bearing system for turbochargers incorporates a thrust collar centrally mounted on the rotating shaft interconnecting the turbine and compressor and a thrust bearing centrally located within the center housing to constrain the thrust collar. Central placement of the thrust collar allows journal bearings and journal seals to be placed immediately adjacent the turbine and compressor wheel attachment points on the shaft enhancing the shaft motion characteristics and sealing capability.

Abstract: A vane and post arrangement for a variable geometry turbocharger employs vanes having a hole in a first end surface receiving a post extending from a surface of the nozzle in the turbine housing. A second end surface on each vane incorporates an extending tab which is received in a respective slot in a unison ring for rotation of the vanes on the posts upon movement of the unison ring.

Abstract: A combination bearing supporting a shaft interconnecting the turbine and compressor wheels of a turbocharger incorporates a dual film floating journal bearing, a squeeze film damper and ball bearing carrier, and a ball bearing assembly. An angular contact ball bearing with an outer race mounted in the carrier rolls on an inner race mounted against a should on the shaft. The squeeze film damper and ball bearing carrier is pinned to preclude axial or rotational movement. A thrust collar is sandwiched between the ball bearing inner race and the compressor wheel to carry thrust loads.