Abstract: A rotor arrangement has a rotor-section and a circumferential moveable seal around the rotor-section. The arrangement being such that, for a given rotation rate, the rotor-section is subject to an associated radial growth and a corresponding related axial displacement, relative to the seal. The rotor-section is provided with an axially-varying profile for off-setting said radial growth of the rotor-section, adjacent the circumferential seal, at said given rotation rate.

Abstract: A rotor arrangement comprising a rotor-section and a circumferential moveable seal around the rotor-section, the arrangement being such that, for a given rotation rate, the rotor-section is subject to an associated radial growth and a corresponding related axial displacement, relative to the seal, wherein the rotor-section is provided with an axially-varying profile for off-setting said radial growth of the rotor-section, adjacent the circumferential seal, at said given rotation rate.

Abstract: A sealing arrangement for sealing a leakage gap between relatively moveable parts in a flow path between a region of high fluid pressure and a region of low fluid pressure comprises a sealing member having an upstream surface, a downstream surface, a radially outer surface and a radially inner surface, the sealing member being in communication with a housing via a resilient element. The resilient element is fixedly joined to the upstream surface of the sealing member such that during operation both the radial force induced on the sealing member by fluid flowing axially into and circumferentially over the radially inner surface and the axial force induced on the sealing member because of a pressure difference across the sealing member is resisted by the resilient element.

Abstract: A sealing arrangement for sealing a leakage gap between relatively moveable parts in a flow path between a region of high-fluid pressure and a region of low fluid pressure comprises a sealing member having an upstream surface, a downstream surface, a radially outer surface and a radially inner surface, said sealing member being in communication with a housing via resilient means. The resilient means is fixedly joined to the upstream surface of the sealing member such that during operation both the radial force induced on the sealing member by fluid flowing axially into and circumferentially over the radially inner surface and the axial force induced on the sealing member because of a pressure difference across the sealing member is resisted by the resilient means.

Abstract: An annular seal comprising a mass of bristles (10) packed together in a layer axially adjacent to an annular backing plate (12). The bristles (12) and backing plate (14) are mounted on and extend from a radially outer member (4) towards and around a cylindrical inner member (2). The outer (4) and inner (2) cylindrical members rotate relative to each other about an axis (1). The bristles (10) co-operate with the inner cylindrical member (2) to form a seal thereagainst. An expansion ring (18) is disposed radially inwardly of the backing plate (14) and is mounted in substantially the same plane from the backing plate (14) via a suitable mounting arrangement (16) which is arranged to permit radial movement of the expansion ring (18) relative to the backing plate (14) and the operational position of the inner cylindrical member (2).