Patent ID: 8360712
Filing Date: 2013-01-29
Classification: F01D,F04D,F05D,F16J

Abstract:
1. A seal assembly for a turbomachine, the turbomachine comprising a stationary housing and a rotor rotating about an axis, the seal assembly comprising: at least one arcuate plate coupled to an interior surface of the stationary housing and positioned in a radial plane; a circumferentially-segmented packing ring disposed intermediate to the rotor and the plate, wherein the packing ring is positioned to move along the plate in a radial direction; a plurality of arcuate teeth disposed intermediate to the packing ring and the rotor, wherein a clearance of each tooth decreases progressively going from an upstream side of the turbomachinery to a downstream side of the turbomachinery, wherein the progressive decrease in the clearances of the teeth creates a passive feedback in the hydrostatic forces generated by differential pressure across the seal assembly, such that as a tip clearance decreases, outward radial forces cause the packing ring to move away from the rotor and as the tip clearance increases, inward radial forces cause the packing ring to move toward the rotor; and a biasing member disposed intermediate to the arcuate plate and the packing ring and coupled to both.