Rotary pressure seal structure and method for reducing thermal stresses therein

Abstract

A rotary member for restricting the flow of high temperature gas from a first cavity, intermediate rotating and stationary members of a gas turbine engine, and a second cavity, includes a central disc bore segment having an inner circumference and an outer circumferential seal segment. A closed cavity is formed by a portion of the rotating member and a portion of the rotating seal disc, with the inner circumference of the central disc bore segment positioned in a predetermined spaced relation with respect to the rotating member, forming a gap therebetween. The closed cavity contains at least one aperture adjacent the outer circumferential seal segment. A portion of the high temperature gas flows through the aperture into the closed cavity, then exits the closed cavity through the gap formed between the inner circumference of the central disc bore segment and the rotating member. The gap in effect presents a constriction which causes a concomitant increase in the velocity of the gas through the gap. The high temperature gas, flowing at a relatively high velocity across the inner circumference of the central disc bore segment reduces the temperature differential between the inner circumference and the outer circumferential seal segment thereby reducing thermal stresses in the rotary seal.

Dependencies are inferred from the claim text.