Composite blade and method for molding composite blade

A composite blade formed by laying up composite layers containing reinforcing fiber and resin, the composite blade comprising:

• a blade root mounted in a blade groove;
• an airfoil extending from the blade root to a front end side;
• and
• a metal patch mounted between the blade groove and the blade root, and bonded to the blade root,
• wherein the blade root is a laminate with the laid-up composite layers and includes:
• airfoil laminates continuous from the airfoil, the airfoil laminates being bonded together at the airfoil and being separated from each other at the blade root,
• a blade root inner laminate mounted on the inner side of each of the airfoil laminates, and
• a blade root outer laminate mounted on the outer side of each of the airfoil laminates,
• wherein the reinforcing fiber is oriented in the blade root inner laminate and the blade root outer laminate so that a linear expansion coefficient of the blade root is approximate to a linear expansion coefficient of the metal patch, and
• wherein when a direction extending from the side of the blade root to the front end side is defined as a length direction and a direction perpendicular to the length direction is defined as a width direction in a mounting surface of the blade root on which the metal patch is mounted, the metal patch includes cuts formed at predetermined intervals in the width direction.

A method for molding a composite blade formed by laying up composite layers containing reinforcing fiber and resin, wherein the composite blade includes:

• a blade root mounted in a blade groove,
• an airfoil extending from the blade root to a front end side, and
• a metal patch mounted between the blade groove and the blade root and bonded to the blade root, and
• wherein the blade root is a laminate with the laid-up composite layers and includes:
• airfoil laminates continuous from the airfoil, the airfoil laminates being bonded together at the airfoil and being separated from each other at the blade root,
• a blade root inner laminate mounted on the inner side of each of the airfoil laminates, and
• a blade root outer laminate mounted on the outer side of each of the airfoil laminates,
• the method comprising:
• a set process of placing the metal patch on a forming mold for molding the blade root;
• a laying-up process of laying up the composite layers on the metal patch and forming the airfoil laminates, the blade root inner laminate, and the blade root outer laminate;
• and
• a hardening process of heating and hardening the airfoil laminates, the blade root inner laminate, and the blade root outer laminate, and
• at the laying-up process, the reinforcing fiber is oriented in the blade root inner laminate and the blade root outer laminate so that a linear expansion coefficient of the blade root is approximate to a linear expansion coefficient of the metal patch,
• wherein when a direction in which the airfoil extends is defined as a 0° direction, orientation ratios of the reinforcing fiber oriented in ±45° directions in the blade root inner laminate and the blade root outer laminate are higher than 30% and lower than 60%.