Abstract: A cavity is defined between the rotating and stationary parts of a gas turbine engine through which cavity air is circulated. Upstream and downstream seals are disposed at opposite ends of the cavity for regulating the circulation of air flowing into and out of the cavity. A cooling air circuit for the engine rotor is provided which channels air from the stationary portion of the engine to the rotor through the cavity therebetween. The rotor air cooling circuit includes an inducer chamber where the cooling air is accelerated and transferred to the engine rotor. The inducer chamber is defined by two additional seals which, in conjunction with the other cavity seals define chambers upstream and downstream of the central inducer chamber. A bypass circuit directs the air circulated within the upstream chamber directly to the downstream chamber (bypassing the inducer chamber) so that the coolant air flowing through the inducer chamber is not contaminated with the air circulated between the engine rotor and stator.

Abstract: A method of enhancing or prolonging the low cycle fatigue life of the bore area of a rotating disk. The method comprises the step of prestressing the bore area by heating the web/rim area of the disk, while moderately overspeeding the disk. The heating can be accomplished with the use of induction heating coils which are disposed adjacent the web/rim area of the disk. This method, unlike prior art prestressing methods, is simple to perform, is cost effective, and does not compromise the disk or the design of the assembly of which the disk is a component.

Abstract: Both the disk and the blade retainer have a radially inward extending flange which axially abuts the other. A U-clip ring with its open side disposed radially outward is placed over the two flanges to hold them axially together and means is provided to maintain the U-clip ring in its holding position. In a preferred embodiment, the ring is constructed with its side farthest from the disk having a substantially greater radial height than that of the side closest the disk, and the circumferential length of the U-clip is so sized that there is a relatively small gap between its ends when it is in the installed position. With these features, the ring will remain in its assembled position without any other holding means. Removal can be effected by first radially moving one end of the ring inwardly with respect to the other and then axially moving it until it clears the other end.