Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% nitrogen, and a balance of iron. Molybdenum, niobium, and tungsten are excluded. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 980° C.

Abstract: An exhaust gas variable geometry turbine assembly can include a number of pivotable vanes that define throats within an exhaust gas nozzle where each of the pivotable vanes includes a corresponding post, where each of the pivotable vanes is made of a first alloy that includes a first amount of nickel by mass, where each of the corresponding posts is made of a second alloy that includes a second amount of nickel by mass and where the second amount of nickel by mass exceeds the first amount of nickel by mass.

Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.5% to about 1.5% tungsten, about 0.2% to about 0.8% molybdenum, about 0.2% to about 0.8% niobium, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% nitrogen, and a balance of iron. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 1020° C.

Abstract: An exhaust gas variable geometry turbine assembly can include a number of pivotable vanes that define throats within an exhaust gas nozzle where each of the pivotable vanes includes a corresponding post, where each of the pivotable vanes is made of a first alloy that includes a first amount of nickel by mass, where each of the corresponding posts is made of a second alloy that includes a second amount of nickel by mass and where the second amount of nickel by mass exceeds the first amount of nickel by mass.

Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% niobium, about 0.2% to about 0.8% nitrogen, and a balance of iron. Molybdenum and tungsten are excluded. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 980° C.

Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.5% to about 1.5% tungsten, about 0.2% to about 0.8% molybdenum, about 0.2% to about 0.8% niobium, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% nitrogen, and a balance of iron. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 1020° C.

Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% nitrogen, and a balance of iron. Molybdenum, niobium, and tungsten are excluded. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 980° C.

Abstract: Disclosed is an austenitic stainless steel alloy that includes, by weight, about 22% to about 28% chromium, about 3.5% to about 6.5% nickel, about 1% to about 6% manganese, about 0.5% to about 2.5% silicon, about 0.3% to about 0.6% carbon, about 0.2% to about 0.8% niobium, about 0.2% to about 0.8% nitrogen, and a balance of iron. Molybdenum and tungsten are excluded. The alloy is suitable for use in turbocharger turbine housing applications for temperature up to about 980° C.

Abstract: A variable geometry turbocharger employs multiple vanes in the turbine inlet with a unison ring and integral cast wall in the turbine housing forming the nozzle walls. An actuator rotates the unison ring through a rack and pinion driven crank shaft to move the vanes through a range of vane positions that extends between a hard-stop closed position and a hard-stop open position, and that includes a reference position corresponding to a desired flow condition. A variable geometry turbine controller uses a sensor indicating the actuation position of the actuator to guide the operation of the vanes to the reference position. The controller intermittently directs the actuator to force the vanes to the hard-stop closed and hard-stop open positions, and uses sensor information from those positions to reestablish the reference-position information that the actuator uses to guide the actuation of the vanes.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.

Abstract: An exemplary vane fronting surface for a variable geometry turbine includes a white layer that comprises nitrides. Such a layer may be formed using gas nitriding. As described, trials demonstrate that such nitriding reduces friction between a vane fronting surface and vanes of a variable geometry turbine. Consequently, nitriding can enhance longevity and controllability of a variable geometry turbine.

Abstract: A variable-nozzle turbocharger includes a turbine housing and a center housing, and a generally annular nozzle ring and an array of vanes rotatably mounted to the nozzle ring such that the vanes are rotatably adjustable for regulating exhaust gas flow to the turbine wheel. An elastically deformable member is disposed between a radially inwardly facing surface of the nozzle ring and a radially outwardly facing surface of the center housing, the elastically deformable member having a radially inner surface contacting the radially outwardly facing surface of the center housing and having a radially outer surface contacting the radially inwardly facing surface of the nozzle ring so as to radially center the nozzle ring relative to the center housing.

Abstract: A variable-nozzle turbocharger includes a cartridge containing a variable vane mechanism connected between the center housing and the turbine housing. The cartridge comprises an annular nozzle ring supporting an array of rotatable vanes, an insert having a tubular portion sealingly received into the bore of the turbine housing and having a nozzle portion extending radially out from one end of the tubular portion and being axially spaced from the nozzle ring with the vanes therebetween, and a plurality of spacers connected between the nozzle portion of the insert and the nozzle ring. The turbine housing has a surface that directly contacts a surface of the nozzle ring that axially faces the insert for axially locating the nozzle ring relative to the turbine housing. A radial gap is defined between the turbine housing and the nozzle ring to allow radial movement of the nozzle ring relative to the turbine housing.

Abstract: A variable geometry turbocharger employs multiple vanes in the turbine inlet with a unison ring and integral cast wall in the turbine housing forming the nozzle walls. An actuator rotates the unison ring through a rack and pinion driven crank shaft to move the vanes through a range of vane positions that extends between a hard-stop closed position and a hard-stop open position, and that includes a reference position corresponding to a desired flow condition. A variable geometry turbine controller uses a sensor indicating the actuation position of the actuator to guide the operation of the vanes to the reference position. The controller intermittently directs the actuator to force the vanes to the hard-stop closed and hard-stop open positions, and uses sensor information from those positions to reestablish the reference-position information that the actuator uses to guide the actuation of the vanes.

Abstract: A vane assembly includes vanes each having an axle and an arm immovably connected with the vane prior to assembling the vane assembly. The vane, axle, and arm can be an integral one-piece structure formed by casting, machining, or metal injection molding. The axles engage apertures in a nozzle ring and are rotatable in the apertures about axes of the vanes. An actuator ring is assembled with the nozzle ring and is rotatable relative thereto. The actuator ring defines connecting elements that connect with cooperative connecting elements on the vane arms. Rotation of the actuator ring causes the vanes to rotate for adjusting the angles of the vanes. During assembly, the motion of inserting the axles into the apertures is also effective for placing the arms in position for connection with the actuator ring.

Abstract: An exemplary vane fronting surface for a variable geometry turbine includes a white layer that comprises nitrides. Such a layer may be formed using gas nitriding. As described, trials demonstrate that such nitriding reduces friction between a vane fronting surface and vanes of a variable geometry turbine. Consequently, nitriding can enhance longevity and controllability of a variable geometry turbine.