Abstract: A rotary machine has a rotor and a surrounding stator. The rotor has an outer surface with an upstream larger-radius first section, a downstream smaller-radius second section, and an intervening third section which has an area facing in a direction other than perpendicular or parallel to the axis of the rotor. In one example, the area includes a first convex area and a second concave area. The machine also has a first brush seal with bristles whose free ends are positioned near the second section, and the machine may also include a second brush seal with bristles whose free ends are positioned near the first section and with a front plate having a ledge projecting away from its corresponding bristles.

Abstract: A brush seal segment useful, when circumferentially arrayed with other such segments, to seal the gap between a rotor and a surrounding casing of a rotary machine such as a gas or steam turbine. Brush-seal bristles are positioned between a brush-seal back plate and a brush-seal front plate with the free end of each bristle extending beyond the edges of the plates. The front plate has a portion extending to the edge of the front plate with the portion spaced apart from the bristles. In one example, the portion has an array of through holes. In another example, the portion has a ledge projecting generally away from the bristles.