Wind turbine blade having at least one longitudinal hollow element that defines an aerodynamic outer surface and an inner cavity having an inner surface. The blade also comprises at least one spar (1), disposed in the inner cavity and bonded to the inner surface by at least two bonding surfaces (13) located on bonding surfaces (2) of the spar (1). The spar (1) comprises, on at least one bonding zone (2), at least three fibre fabric layers (3) and at least one central core (4) and at least one lateral core (5) disposed between the at least three fibre fabric layers (3). This makes it possible to increase the resistance to shear stresses in the adhesive bond of the spar (1) to the inner surface of the longitudinal hollow element and decrease the required amount of adhesive.

A method of coating an area of a wind turbine rotor blade comprises: defining an area to be coated on a surface of the blade, applying a first plurality of strips of masking tape to the surface of the blade proximate a first edge region of the defined area such that each strip is arranged adjacent to at least one other strip of said first plurality of strips, spraying a coating layer onto the defined area up to an innermost strip such that the innermost strip defines an edge of the coating layer, removing the innermost strip(s) to expose an uncoated region of the defined area between the edge of the coating layer and an innermost remaining strip and spraying a further coating layer over the previous coating layer and over the uncoated region up to said innermost remaining strip.

Wind turbine blade having at least one longitudinal hollow element that defines an aerodynamic outer surface and an inner cavity having an inner surface. The blade also comprises at least one spar (1), disposed in the inner cavity and bonded to the inner surface by at least two bonding surfaces (13) located on bonding surfaces (2) of the spar (1). The spar (1) comprises, on at least one bonding zone (2), at least three fibre fabric layers (3) and at least one central core (4) and at least one lateral core (5) disposed between the at least three fibre fabric layers (3). This makes it possible to increase the resistance to shear stresses in the adhesive bond of the spar (1) to the inner surface of the longitudinal hollow element and decrease the required amount of adhesive.

An integral ring gear and torque arm for a wind turbine gearbox and method of manufacturing same includes forming the ring gear and the associated gear housing as a single part using the same material, e.g., using a casting process. Further, the ring gear defines an inner circumferential surface having a plurality of gear teeth. Thus, the method also includes applying a coating material to the gear teeth of the ring gear via an additive manufacturing process, such as cold spraying, so as to increase a hardness of gear teeth.

An integral ring gear and torque arm for a wind turbine gearbox and method of manufacturing same includes forming the ring gear and the associated gear housing as a single part using the same material, e.g., using a casting process. Further, the ring gear defines an inner circumferential surface having a plurality of gear teeth. Thus, the method also includes applying a coating material to the gear teeth of the ring gear via an additive manufacturing process, such as cold spraying, so as to increase a hardness of gear teeth.