Variable geometry turbine nozzle

Abstract

The invention is concerned with an improvement in a movable vane assembly of the type used in a gas turbine engine or compressor for interaction with a gas stream comprising a plurality of radially aligned vanes, generally of an air foil configuration, circumferentially arranged within an annular passage formed by a housing, said vanes being supported for rotation about their radial axis to vary the effective cross-sectional area of said annular passage, a plurality of rotatable gear means connected for rotation with said aligned vanes and a ring gear having teeth means adapted for simultaneous engagement with the teeth means of said rotatable gear means such that rotation of said ring gear causes rotation of said vanes. In one sense the improvement comprises a support for the ring gear supportingly connected to the first housing inwardly radially and coaxial with the ring gear, the support comprising an annular ring having longitudinally extending slot means therein. In another sense, the improvement is in a movable vane assembly as set out above which includes an outer shroud supportingly connected to the housing and an inner shroud radially inwardly spaced from the outer shroud. In this other sense, the improvement comprises a plurality of circumferential thrust segments having a well therein generally centrally thereof, adjacent of said segments having overlapping means, said segments fitting together to form a close fitting shroud for the inner ends of said vanes; a plurality of extending members, one proceeding inwardly radially along the rotational axis from each of said vanes, said extending member each being rotatably located within a respective one of said well and a collar extending from said inner shroud inwardly radially of said shroud in supporting relation thereto. In yet another sense the removable vane assembly includes a plurality of link means for actuating the ring gear and the improvement comprises using as each of said link means a pin with an eccentric flange extending centrally therefrom and including as part of said ring gear a plurality of recesses which mate with said eccentric flanges whereby said pins are removable from said ring gear using a single wrench.