US Patent 10094224 Rotor blade and fan

A rotor blade main body includes multiple first composite sheet groups and multiple second composite sheet groups which are provided in a blade thickness direction. Each first composite sheet group includes multiple composite sheets which are stacked one on another from a blade thickness center side toward a dorsal surface. Each second composite sheet group includes multiple composite sheets which are stacked one on another from the blade thickness center side toward a ventral surface. A composite direction of orientation directions of fibers in the multiple composite sheets in each of the sheet groups inclines by 20 degrees to 45 degrees from a span direction.