Patent ID: 8702394
Filing Date: 2014-04-22
Classification: B22C,F04D,F05D

Abstract:
1. A turbocharger comprising: a compressor housing having an air inlet and an air outlet; and a centrifugal compressor wheel mounted for rotation within the compressor housing, the compressor wheel being comprised predominantly of titanium, and comprising a hub defining an axis of rotation, and a plurality of backswept blades carried on a surface of the hub and defining air passages between adjacent blades, the compressor wheel being defined by investment casting using a compressor wheel pattern comprising backswept pattern blades defining pattern air passages between adjacent pattern blades, the compressor wheel pattern being formed by introducing a sacrificial material into a die comprised of a plurality of die inserts, wherein each of the pattern air passages is defined by at least a first die insert and a second die insert which can be pulled from between the pattern blades without deformation of the first and second die inserts or pattern blades, and automatically extracting the die inserts radially or along a curve to expose the compressor wheel pattern, wherein an extraction direction of the first die inserts is different than an extraction direction of the second die inserts.