Patent ID: 7823887
Filing Date: 2010-11-02
Classification: F04D,F16J

Abstract:
1. A seal for sealing between components of a rotary machine at an annular sealing interface where opposing surfaces of the components define an enclosed or partially enclosed seal volume, of generally predetermined shape, configuration and orientation, between relatively high pressure and low pressure zones, the seal being in the form of a ring of pliable material and defining a plurality of cavities arranged to accept deformed material to allow deformation of the material of the seal into the cavities, the seal including a base having an annular radially inner limb, an annular radially outer limb spaced radially outwardly from the inner limb and a web extending between ends of the radially inner and outer limbs such that the base is generally U-shaped in axial cross-section, an annular skirt which forms an extension of the inner limb and which extends generally longitudinally beyond the radially outer limb, which has radially inner and outer peripheral surfaces, and which is generally wedge shaped, the skirt tapering from a relatively thicker cross-section to a relatively thinner cross-section at a taper or free end thereof, which is intended to be positioned at a high pressure zone of the seal volume, in which said cavities alternate with land areas, the cavities and land areas being distributed peripherally, the land areas being in the form of elongate longitudinally oriented fingers which extend longitudinally from a back of the base between the radially inner and outer limbs beyond the radially outer limb to the free end of the skirt such that circumferentially spaced longitudinally extending cavities are provided between the land areas, cross-sectional surfaces through the land areas at respective radii decreasing progressively from a surface of the skirt to cause a compressive force, required to cause deformation of the land areas, to increase exponentially with an exponent larger than 1, the outer limb sloping towards the skirt away from the base and the land areas being chamfered towards their free ends.