Abstract: A compressor stage or a turbocharger having a compressor stage having an inducer shroud with two or more vents. A first vent is provided with a second vent upstream thereof, allowing for outflow during surge conditions and inflow during choking conditions. Surge line characteristics may be varied by selectively locating the position of the first and of the second vents, and by selectively determining the effective width of the vents. The vents may be circumferential slots, and may be slanted. An outer shroud is provided forming a venting chamber for recirculation of gas into the gas intake. A third vent may be provided to vent the diffuser.

Abstract: A torsional vibration damper having two inertia members. A first inertia member is coupled to a hub by elastomer. A second inertia member is positioned within an annular cavity and is surrounded by a liquid of high viscosity. Under the influence of torsional vibrations relative movement arises between the hub and first inertia member, the hub and the second inertia member, and the first and second inertia members. The latter relative motion inhibits the attainment of resonance by either of the two inertia members.