Dovetail structure of fan

摘要

The invention provides a dovetail structure of a fan which attaches the fan 20 having an inlet hub diameter smaller than an outlet hub diameter to a portion around a discoid disc 10 rotationally driven by a turbine. The disc 10 has a plurality of main dovetail grooves 12 extending in parallel to an axis 1 of a rotation axis from a leading edge to a trailing edge thereof. The fan 20 has a main dovetail portion 22 fitted to the main dovetail groove 12, and a sub engagement portion 24 for supporting a front centrifugal force. Further, the dovetail structure is provided with a spin cone 30 engaging with the sub engagement portion 24 so as to be capable of transmitting the front centrifugal force to the disc 10.