United Technologies Corporation

Sundstrand Corporation

John Craig Lentz

Edward S Blain

Peter D Waters

David B Wigmore

A compressor impeller for an Auxiliary Power Unit (APU) includes a hub including a plurality of splitter blades interposed between a plurality of main blades. Each of the plurality of splitter blades and the plurality of main blades include a first surface and a second surface. The first surface and the second surface of the plurality of splitter blades are defined as a set of X-coordinates, Y-coordinates and Z-coordinates set out in Table S-1 and S-2 scaled by a desired factor. The X-coordinate being in an axial direction, the Y-coordinate being in a first radial direction and the Z-coordinate being in a second radial direction transverse to the first radial direction. Each of the plurality of splitter blades includes a contour between the tip and the leading edge. An auxiliary power unit and method are also disclosed.

Auxiliary power unit impeller blade

A refrigeration system (10) having a compressor rotor (20) rotatably supported by a plurality of hydrodynamic bearings (22 and 24) lubricated by oiless pressurized liquid refrigerant and pressurizing refrigerant which flows to a condenser (34) providing liquid refrigerant which flows to an evaporator (68) in fluid communication with the condenser and the compressor in accordance with the invention includes a refrigeration circuit (36) coupled to the compressor, for providing pressurized refrigerant to the hydrodynamic bearings from the compressor and to the evaporator; a bearing pump (26), coupled to the refrigerant circuit and to the condenser, for providing pressurized refrigerant to the refrigeration circuit; a first temperature sensor (101) sensing a temperature Tsink of a heat exchange fluid at the condenser and providing a temperature signal representative of the temperature Tsink of the heat exchange fluid at the condenser; a second heat exchange sensor (103) sensing a temperature Tsource of a heat exchange fluid at the evaporator and providing a temperature signal representative of the temperature Tsource of the heat exchange fluid at the evaporator; and a controller (28 ), coupled to the temperature sensors, for controlling activation of the compressor and bearing pump as a function of the temperature signals to provide for three modes of operation with the first mode of operation being activation of only the compressor, the second mode of operation being activation of the bearing pump and the compressor and the third mode of operation being activation of only the bearing pump.

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Poway, CA, United States of America

John Craig Lentz