Gas turbine spindle bolt structure with reduced fretting fatigue

摘要

A spindle bolt structure is provided in a gas turbine engine, and includes a pilot region located within a bolt hole extending through a seal disk. The pilot region includes a circumferential pilot ridge located adjacent to a downstream axial face of the seal disk and a circumferential trough portion located between a bolt shoulder and the pilot ridge. The trough portion defines a trough diameter that is less than a diameter of the bolt shoulder and less than a diameter of the pilot ridge. The bolt shoulder and pilot ridge are formed with an applied compressive residual stress and are positioned for engagement with the seal disk.

主权项

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.