Patent ID: 9598961
Date: 2017-03-21
CPC Classifications: F01D,F04D,F05D

Claim:
1. In a gas turbine engine, a rotor including a plurality of turbine disks for supporting rows of blades, a torque tube located on a compressor side of the turbine disks, and a seal disk located between the torque tube and a first stage turbine disk, a spindle bolt structure comprising: a spindle bolt extending through the turbine disks and disposed offset from a rotational axis of the turbine disks; the seal disk including an upstream axial face and an opposing downstream axial face, and a bolt hole extending between the upstream and downstream axial faces; the spindle bolt extending through the bolt hole and including a bolt shoulder engaged on the seal disk within the bolt hole; a pilot region formed on the spindle bolt and located within the bolt hole for effecting a reduction in fretting fatigue of the spindle bolt, the pilot region including a circumferential pilot ridge located in the bolt hole adjacent to the downstream axial face of the seal disk and a circumferential trough portion located between the bolt shoulder and the pilot ridge, the trough portion defining a trough diameter that is less than a diameter of the bolt shoulder and that is less than a diameter of the pilot ridge.