Patent ID: 8820752
Filing Date: 2014-09-02
Classification: F01D,F02C,F05D,F16J

Abstract:
1. An intershaft seal assembly interposed between an inner shaft and an outer shaft about a common axis within a turbine engine so as to separate a low pressure side from a high pressure side comprising: (a) a pair of annular end rings disposed about and directly contacts said inner shaft; (b) an annular seal element formed by at least two seal segments, each said seal segment has an inverted “T”-shaped cross section, said seal segments disposed between said annular end rings so that a portion of said inverted “T”-shaped cross section extends above said annular end rings in direction of said outer shaft, each said seal segment includes a pair of shoulders which extend from said seal segment between said annular end rings and said inner shaft; (c) at least one resilient element which biases said seal segments away from said inner shaft toward said outer shaft; (d) an annular spacer ring disposed about and directly contacts said inner shaft, said annular spacer ring disposed between and attached to said annular end rings, said annular seal element disposed about said annular spacer ring; (e) a pair of carriers disposed between said annular end rings about said annular seal element, said carriers directly contact said annular spacer ring; (f) at least two counterweights oppositely disposed about said seal segments, each said counterweight attached to one said carrier and contacts one said shoulder, said counterweights substantially negate forces acting on said seal segments outward toward said outer shaft; and (g) a plurality of hydrodynamic grooves disposed along an inner annular surface of said outer shaft, said hydrodynamic grooves direct fluid onto an outer surface along each said seal segment when said outer shaft rotates, said fluid forms a thin-film layer which separates said seal segments from said outer shaft.