VARIABLE CLEARANCE PACKING RING SEGMENT ASSEMBLY AND TURBINE DIAPHRAGM

PROBLEM TO BE SOLVED: To provide a method and a device for a variable clearance packing. SOLUTION: A packing ring segment assembly 15 for seals a gap between two regions 34, 36 of an article comprises a sealing portion 22 including radially inwardly directed teeth 26 and a dovetail mounting portion 20. The dovetail mounting portion comprises a hollowed out portion 216 including a biasing member 236 internal to the dovetail mounting portion. The biasing member is coupled to the dovetail mounting portion and configured to engage a pair of annular shoulders of a dovetail groove 23 in the article such that the packing ring segment assembly is biasing radially outward at relatively low differential pressure between the two regions. At a relatively high differential pressure between the two regions, the differential pressure overcomes the radial biasing member forces and urges the sealing portion radially inward. The dovetail portion is movable in a first direction. COPYRIGHT: (C)2008,JPO&INPIT