Turbine blade attachment stress reduction rings

摘要

A turbine or compressor disk assembly comprises a plurality of blades attached to a central hub by means of the blade root of each blade engaging a corresponding slot in the hub. According to the principles of the present invention, a turbine or compressor disk assembly includes one or more locally bulging regions extending axially away from the surface of the disk in the vicinity of the bottom contact plane of the disk attachment firtree. The locally bulging regions reduce the peak Macke stress in the disk bottom fillet and blade attachment root. In an illustrative embodiment, two locally bulging regions are incorporated into the disk and the corresponding blades, one of which extends forward from the leading edge of the disk and the other of which extends rearward from the trailing edge of the disk. The rearward locally bulging region has an exaggerated extension which allows the stress reduction ring to form an aft flow discourager as well as functioning to reduce peak stress.