US 12,345,162 B2
Adjustable position impeller shroud for centrifugal compressors
Michael Nesteroff, Indianapolis, IN (US); Mark E. Whitlock, Indianapolis, IN (US); Nathanael Cooper, Indianapolis, IN (US); and Jonathan Acker, Indianapolis, IN (US)
Assigned to Rolls-Royce Corporation, Indianapolis, IN (US)
Filed by Rolls-Royce Corporation, Indianapolis, IN (US)
Filed on Nov. 17, 2023, as Appl. No. 18/512,672.
Prior Publication US 2025/0163820 A1, May 22, 2025
Int. Cl. F04D 29/42 (2006.01); F01D 11/16 (2006.01); F01D 11/22 (2006.01); F01D 17/12 (2006.01); F04D 29/46 (2006.01)
CPC F01D 11/22 (2013.01) [F01D 11/16 (2013.01); F01D 17/12 (2013.01); F04D 29/4206 (2013.01); F04D 29/464 (2013.01); F05D 2230/60 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A compressor assembly for a gas turbine engine, the compressor assembly comprising
an impeller arranged around an axis and configured to rotate about the axis to provide compressed air,
a shroud assembly that extends circumferentially around the impeller to direct the compressed air through the impeller, the shroud assembly includes a case mount that couples the shroud assembly to the outer case assembly, an impeller shroud which confronts the impeller, and a shroud body that extends between and interconnects the impeller shroud and the case mount,
an outer case assembly configured to support the shroud assembly at a desired axial location relative to the impeller, the outer case assembly having an outer case that extends circumferentially around the axis and a plurality of fasteners that extend into the outer case and the shroud assembly to couple the shroud assembly with the outer case, and
a plurality of locating bolt assemblies that allow adjustment of the axial location of the shroud assembly relative to the outer case and the impeller, the plurality of locating bolt assemblies extend axially into the outer case and have terminal ends that terminate at a predetermined axial location relative to the impeller and abut the shroud assembly such that the plurality of fasteners urge the shroud assembly into abutting contact with the terminal ends of the plurality of locating bolt assemblies at an axial locating surface to axially locate the shroud assembly relative to the impeller to provide a desired size of a gap between the shroud assembly and the impeller at cold build of the compressor assembly,
wherein the shroud body includes an air piston formed to define a chamber adapted to receive actuation air to selectively move the impeller shroud axially relative to the impeller to adjust the size of the gap between the shroud assembly and the impeller during use of the compressor assembly.
 
8. A compressor assembly for a gas turbine engine, the compressor assembly comprising
an impeller arranged around an axis and configured to rotate about the axis to provide compressed air,
a shroud assembly that extends circumferentially around the impeller to direct the compressed air through the impeller, the shroud assembly includes a case mount that couples the shroud assembly to the outer case assembly, an impeller shroud which confronts the impeller, and a shroud body that extends between and interconnects the impeller shroud and the case mount,
an outer case assembly configured to support the shroud assembly at a desired axial location relative to the impeller, the outer case assembly having an outer case that extends circumferentially around the axis and a plurality of fasteners that extend into the outer case and the shroud assembly to couple the shroud assembly with the outer case, and
a plurality of locating bolt assemblies that allow adjustment of the axial location of the shroud assembly relative to the outer case and the impeller, the plurality of locating bolt assemblies extend axially into the outer case and have terminal ends that terminate at a predetermined axial location relative to the impeller and abut the shroud assembly such that the plurality of fasteners urge the shroud assembly into abutting contact with the terminal ends of the plurality of locating bolt assemblies at an axial locating surface to axially locate the shroud assembly relative to the impeller to provide a desired size of a sap between the shroud assembly and the impeller at cold build of the compressor assembly,
wherein the shroud body is shaped to define a U-shaped cross section when viewed normal to the axis, the U-shaped cross section includes a concave surface exposed to a first pressure and a convex surface exposed to a second pressure wherein changes to the first and second pressures cause the shroud body to flex and move the impeller shroud axially during use of the compressor assembly.