The United States of America As Represented by the Administrator of the

The United States of America As Represented by the United States

The United States of America As Represented by the Administrator

Lawrence P Ludwig

Robert C Bill

William F Hady

A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a yieldingly deformable porous material covered with a thin ductile layer. A mounting fixture surrounds the backing.

Composite seal for turbomachinery

A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polyimide and graphite fiber composite.

Circumferential shaft seal

A circumferential shaft seal comprising two sealing rings held to a rotating shaft by means of a surrounding elastomeric band. The rings are segmented and are of a rigid sealing material such as carbon or a polymide and graphite fiber composite.

A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing is a compliant material covered with a thin ductile layer. A mounting fixture surrounds the backing.

A seal assembly is provided for reducing the escape of fluids from between a housing and a shaft rotatably mounted in the housing. The seal assembly comprises a pair of seal rings resiliently connected to each other and disposed in side-by-side relationship. In each seal ring, both the internal bore surface and the radial face which faces away from the other seal ring are provided with a plurality of equi-spaced recesses known as Rayleigh step pads. The seal faces referred to are located adjacent a seating surface of the housing. Under normal operating conditions, the seal assembly is stationary with respect to the housing, and the recesses generate lift, keep the assembly spaced from the rotating shaft and allow slip therebetween. Due to expansion of the shaft resulting from rubbing contact with the seal assembly, the seal assembly can seize on the shaft, and slip will then occur between the radial faces and the housing. The shaft will subsequently cool down due to the reduction or elimination of rubbing contact between the shaft and the seal assembly, and the seal assembly will heat up with resultant thermal expansion due to rubbing contact with the housing. As the seal assembly expands, slipping once again occurs between the seal assembly and the shaft. Thus, the seal ring assembly provides thermal stabilization. Preferably metallic bands are shrunk fit about each of the seal rings which are comprised of carbon graphite, so as to match the coefficient of expansion of a metallic shaft and the seal assembly.

Shaft seal assembly for high speed and high pressure applications

A gas path seal suitable for use with a turbine engine or compressor is provided. A shroud wearable or abradable by the abrasion of the rotor blades of the turbine or compressor shrouds the rotor blades. A compliant backing surrounds the shroud. The backing may be made of corrugated sheets or the like with adjacent layers having off-set corrugations, with axes of the folds parallel to the rotor axis. The sheets may be bonded together at points of contact by brazing, welding or the like. In another embodiment a compliant material is covered with a thin ductile layer. A mounting fixture surrounds the backing.

This application discloses a dirt separator and excluder for removing entrained debris from gas turbine shaft seals. A helical groove pattern is constructed on the rotating shaft with the pumping pattern such that it tends to pump seal pressurizing gas toward the gas turbine seal. A second helical groove pattern is provided on the stationary housing or counter rotating member coaxial with the shaft, and this pattern is designed to provide pumping in the direction opposite from that of the groove pattern on the shaft. Gas with entrained debris entering this grooved area will be subjected to high centrifugal forces due to the swirl motion induced by the groove pattern and the rotation of the shaft. This debris is centrifuged outwardly into the outer groove pattern on the housing or counter rotating member. Since the outer groove pattern has a pumping direction opposite from that of the seal, dirt is pumped away from the seal and can be collected in a suitable debris trap remote from the seal location.

Counter pumping debris excluder and separator

An improved fluid seal for a rotating shaft is provided which includes an inner annular ring or runner adapted to be secured to the rotating shaft and a composite sealing ring which is keyed to the inner ring and includes a radial sealing surface. An outer, nonrotating, annular ring or housing which is concentrically disposed with respect to the runner and sealing ring, includes a radial sealing surface which sealingly engages the sealing surface of the sealing ring. A circular wave spring, which is anchored to the housing and is disposed between the composite sealing ring and a snap ring secured to the housing, provides an axial force which forces the two sealing surfaces into sealing contact. The waves of the spring act as individual hydrodynamic bearings, and the axial force is transmitted across an oil film. This eliminates rubbing contact and the need for a separate thrust bearing.

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Fairview Park, OH, United States of America

Lawrence P Ludwig