Abstract: A centrifugal compressor is modified by forming a bypass between the leading edge of the compressor diffuser and a point downstream from the throat of the diffuser. The bypass may be unidirectional or bi-directional. In a bi-directional embodiment, an operable flow range of the compressor can be widened in both directions of a compressor map, i.e., extending both the surge and choke margins of a compressor at the expense of normal operating efficiencies. In a unidirectional bypass embodiment the flow range may be increased only in one direction, but there is no diminishment of efficiency of the compressor at normal operating conditions. The modification provides a simple expedient for increasing flow range without a need to redesign a compressor.

Abstract: A centrifugal compressor is modified by forming a bypass between the leading edge of the compressor diffuser and a point downstream from the throat of the diffuser. The bypass may be unidirectional or bi-directional. In a bi-directional embodiment, an operable flow range of the compressor can be widened in both directions of a compressor map, i.e., extending both the surge and choke margins of a compressor at the expense of normal operating efficiencies. In a unidirectional bypass embodiment the flow range may be increased only in one direction, but there is no diminishment of efficiency of the compressor at normal operating conditions. The modification provides a simple expedient for increasing flow range without a need to redesign a compressor.

Abstract: A method of sealing at least a first seal surface to a second seal surface comprises the steps of placing a flexible ring member between the first and second seal surfaces and juxtaposing the first and second seal surfaces. The flexible ring member is compressed between the first and second seal surfaces. Thereafter, the flexible ring member is expanded into at least one of a first recessed area in the first seal surface and a second recessed area in the second seal surface, with at least one of the first and second recessed areas having a plurality of spaced apart pressure points that contact the ring member. This method of sealing assures that when the O-ring (flexible ring) permanently sets over time, it takes the shape that makes the seal effective for a long time under high temperature, high pressure.

Abstract: An improved boreless compressor wheel and method for making same by utilizing an internally threaded nut member. The compressor wheel is either cast about the nut, or includes a cup friction welded to the compressor wheel, and carrying the nut member.

Abstract: A compressor wheel assembly for turbochargers and the like comprises a compressor wheel including a boreless hub formed integrally as by casting with a circumferential array of aerodynamically contoured centrifugal impeller blades. The wheel hub is secured at its base by inertia welding to a thrust spacer sleeve having an internally threaded bore for threaded reception of a rotatable shaft. In use of the compressor wheel assembly, the absence of a bore within the wheel hub substantially improves wheel fatigue life.