US 12,392,251 B2
Diametrically expandable/collapsible piston seal
Jason B. Husband, South Glastonbury, CT (US); Canio Michael Hoffarth, Wadde, AZ (US); and Philip Andrew Varney, Coventry, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RAYTHEON TECHNOLOGIES CORPORATION, Farmington, CT (US)
Filed on Jul. 6, 2023, as Appl. No. 18/348,285.
Prior Publication US 2025/0012197 A1, Jan. 9, 2025
Int. Cl. F01D 11/00 (2006.01)
CPC F01D 11/006 (2013.01) [F01D 11/005 (2013.01); F05D 2230/60 (2013.01); F05D 2240/55 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A gas turbine engine comprising:
a rotor having a seal surface;
a shaft rotatable about an engine central axis, the shaft having an annular seal channel that opens to the seal surface;
a seal for sealing against the seal surface, the seal having first and second opposed axial faces, the seal having channels formed therein, radially inner and outer faces, and an annular groove that opens at the radially inner face, the channels are axial through-channels that open at each of the first and second opposed axial faces, and the channels define a tortuous seal wall with interconnected spring ligaments such that the seal is elastically diametrically expandable for installation clearance around the shaft and, once on the shaft, elastically diametrically collapsible into the annular seal channel; and
a flexible sealant disposed in the channels and the annular groove, the flexible sealant sealing the channels with respect to flow between the first and second opposed axial faces.