초록 ▼

Circumferentially extending sealing segments (45) are disposed about a rotary component (16) and have seal face (34) carrying a plurality of labyrinth seal teeth (36) and a brush seal (37). The segments are movable between large and small clearance positions relative to the rotor at start-up and ste

Circumferentially extending sealing segments (45) are disposed about a rotary component (16) and have seal face (34) carrying a plurality of labyrinth seal teeth (36) and a brush seal (37). The segments are movable between large and small clearance positions relative to the rotor at start-up and steady-state operating conditions, respectively. In one form, springs (31) bias the segments radially outwardly at start-up and steam pressure displaces the segments to the small clearance positions at steady-state operations. In a further embodiment, springs bias the segment for movement to the small clearance position, the extent of movement being determined by thermal expansion of centering rings mounting the segments to the stationary components.

대표청구항 ▼

[ What is claimed is:] [1.]1. For use in a machine having a component rotatable about an axis, a stationary component about said axis, and supports carried by said stationary component about said axis, a variable clearance packing ring comprising:a packing ring segment about said axis, said segment

[ What is claimed is:] [1.]1. For use in a machine having a component rotatable about an axis, a stationary component about said axis, and supports carried by said stationary component about said axis, a variable clearance packing ring comprising:a packing ring segment about said axis, said segment having an arcuate seal face in opposition to the rotatable component, at least a first arcuate flange extending in an axial direction and a brush seal extending from said arcuate seal surface toward said rotatable component and having a plate on at least one side thereof;an element engageable by one of the supports and engaging said first flange at a first location therealong for maintaining said segment seal face and brush seal in a first clearance position relative to the rotating component;said element having a coefficient of thermal expansion greater than a coefficient of thermal expansion of said segment, said element engaging said first flange at a second location therealong in response to relative thermal expansion of said segment and said element, enabling said segment for displacement radially inwardly relative to said element to locate said seal face and said brush seal in a second clearance position relative to the rotating component and radially inwardly of said first clearance position.