Replaceable variable stator vane for gas turbines

摘要

A method of removing an inlet guide vane from a lower inlet casing of a compressor, the lower inlet casing adapted to be secured to an upper inlet casing at a horizontal joint, and after removal of the upper half of the inlet casing but with a rotor of the compressor remaining in place, wherein the inlet guide vane is supported between radially inner and outer walls of the lower inlet casing, and further wherein the inlet guide vane is formed with an integral stem that extends radially through the outer wall and supports a drive gear (56) on its outer end that engages an annular gear rack (64), the method including a) removing the gear 56 on the radially outer end of the integral stem of the inlet guide vane; b) shearing the inlet guide vane into two cut portions; c) removing the cut portions from inside the lower inlet casing. A new inlet guide assembly is provided for replacing the vane (10). The new assembly includes a vane (40) having a cylindrical stub at a radially inner end thereof and a relatively short integral stem (44) at a radially outer end thereof; a jack shaft (50) adapted for connection at a radially inner end thereof to a radially outer end of the integral stem (44) such that torque applied to the jack shaft (50) is transmitted to the vane (40), a radially outer end of the jack shaft (50) adapted to receive a drive gear (56). An outer stem piece (58) is seated on the jack shaft and welded to the drive gear to complete a torque transmission path from the drive gear to the vane. <IMAGE>