Turbomachine interstage seal assembly

In an axial flow turbomachine having an annular array of stator vanes with inner shroud segments secured to said vanes, a rotor disc radially inwardly of said shroud segments and supporting an annular array of rotor blades disposed axially adjacent said stator vanes, and a seal assembly disposed between said inner shroud segments and said rotor disc, said assembly comprising:

• a pair of opposed flange members extending radially inwardly from said shroud segments, and separated a predetermined axial dimension, with each of said flange members defining radially extending slots;
• a pair of seal ring holding members disposed within the axial dimension between said opposed flange members, each holding member having a face defining an axially extending key portion for receipt within an aligned slot in said flange with said face abutting said flange, and an opposite terminal end, with said terminal ends of each pair being axially spatially separated a predetermined distance;
• a seal ring comprising a sealing member for facing contact with said rotor disc and means for mounting said sealing member on said holding members, said mounting means in cooperation with said seal ring holding members providing complimentary track and channel engagement, said mounting means further defining a radially extending portion disposed between the opposed terminal ends of said seal ring holding members to limit the axial movement of each holding member to less than the axial dimension of the key portion;
• whereby, after the seal ring is circumferentially slid into position on said seal holding members, said keys of said seal holding members are prevented from axial disengagement from within the slots of said flanges;
• and,
• means for attaching the seal ring to at least one of said seal holding members to prevent circumferential movement of one with respect to the other.