US Patent 7293957 Vane platform rail configuration for reduced airfoil stress

A vane assembly for a gas turbine engine is disclosed having lower thermally induced stresses resulting in improved component durability. The stresses in the vane assembly airfoils are lowered by increasing the flexibility of the vane platform and reducing its resistance to thermal deflection. This is accomplished by placing an opening along the innermost vane assembly rail that reduces the effective stiffness of the platform, thereby lowering the operating stresses in the airfoils of the vane assembly. A removable seal is then placed in the opening in order to prevent undesired leakages, while maintaining the benefit of the increased platform flexibility.