A root bushing for a wind turbine rotor blade, a wind turbine rotor blade, a wind turbine and a method for manufacturing a wind turbine rotor blade for a wind turbine

A root bushing (9) for a wind turbine rotor blade (5), wherein the root bushing (9) has a cylindrical shape with longitudinal grooves (15). The root bushing has the advantage that a bonding area between the root bushing and the fiber composite material is enlarged in comparison to known cylindrical root bushings.