US Patent 8251658 Tip cap for turbine rotor blade

A turbine rotor blade with a spar and shell construction, and a tip cap that includes a row of teeth and slots extending from a bottom side that engage with similar shaped teeth and slots on a tip end of the spar to secure the tip cap to the spar against radial displacement. The tooth on the trailing edge end of the tip cap is aligned perpendicular to the pressure side wall of the blade in the trailing edge region in order to minimize stress due to the teeth wanting to bend under high centrifugal loads. To reduce stress, some of the teeth include a cutback to shorten the teeth in places where high stress levels would occur.