Isolated reverse turbine system for gas turbine engines

A reversible gas turbine engine, in combination:

• a gas generator for discharging working fluid into an annular flow channel;
• a power turbine affixed to an output shaft which is rotatably mounted downstream of said gas generator, for rotating said output shaft in one direction;
• means coupled to the inlet of said power turbine and to the exhaust of said gas generator for diverting said working fluid away from the inlet of said power turbine;
• said means being annular and mounted coaxially with said turbine, and, said means further comprising:
• a plurality of radially movable diverter blocks, each of said blocks comprising a segment of an annular ring and having an upstream face of streamlined cross-section, each of said diverter blocks further being shaped in a manner such that when fully inserted radially inward into said annular flow channel, said diverter blocks form a closed annular ring that completely blocks said flow channel;
• an anchor post, having a flared end, perpendicularly affixed to the downstream face of each of said diverter blocks with said flared end facing downstream;
• a pair of parallel alignment faces formed onto the sides of each of said diverter blocks, said alignment faces running a portion of the length of said diverter blocks in a radial direction;
• a plurality of fixedly mounted radial slide-ways, each of said slide-ways configured for slidable insertion of a corresponding diverter block, whereby said diverter blocks are constrained to move only in a radial direction by said alignment faces and said anchor posts;
• a first drive means coupled to said diverter blocks for radially moving said diverter blocks into or out of said annular flow channel;
• a plurality of circumferentially spaced flaps hingedly mounted on the outer wall of said annular flow channel, one of said flaps being provided for each of said diverter blocks, and each of said flaps being movable only in a radially outward direction and configured to permit said diverter blocks to move into and out of said annular flow channel when said flaps are opened;
• and
• a second drive means for opening and closing said flaps in unison;
• a reverse turbine, having at lease one stage, affixed to said output shaft downstream of said power turbine for rotating said output shaft in an opposite direction, said reverse turbine being oriented in such a manner that its exhaust end faces the exhaust end of said power turbine;
• means coupled to said diverting means and the inlet of said reverse turbine for transferring said working fluid therebetween;
• a shut-off valve mounted within the downstream portion of said transferring means, for restricting the working fluid flow therethrough;
• exhaust blocking means slidably mounted between the exhaust of said power and said reverse turbines and configured so that said exhaust blocking means can selectively block the exhaust end of one or the other of said turbines, or can be positioned at some point therebetween;
• and
• exhaust means coupled to said exhaust blocking means for collecting the working fluid from the exhaust of either or both of said turbines and discharging it therefrom.