Laminate structure for a flange connection of a wind turbine rotor blade, connecting element, wind turbine rotor blade and method for manufacturing a laminate structure

A laminate structure for a flange connection of a wind turbine rotor blade, the laminate structure comprising:

• at least one connecting element including a bushing and a core element;
• said bushing having a first end defining a bore hole with an inner thread configured to accommodate a connection bolt;
• said bushing having a second end including a bushing runout defining an inner recess;
• said inner recess being funnel-shaped;
• said core element including an inner portion, a middle portion, and an outer portion;
• said outer portion tapering at an end opposite to said inner portion;
• said inner portion having a shape corresponding to said inner recess;
• a first laminate layer wrapped around said inner portion and said middle portion of said core element;
• and,
• said core element with said first laminate layer wrapped around said inner portion and said middle portion being inserted into said inner recess with said inner portion such that said first laminate layer is arranged between said core element and said bushing runout.

A connecting element for a flange connection of a wind turbine rotor blade, the connecting element comprising:

• a bushing having a first end and a second end;
• a core element;
• said first end of said bushing defining a bore hole with an inner thread configured to accommodate a connection bolt;
• said second end of said bushing having a bushing runout defining an inner recess;
• said inner recess being funnel-shaped;
• said core element including an inner portion, a middle portion, and an outer portion;
• wherein said outer portion tapers at an end opposite to said inner portion;
• said inner portion having a shape corresponding to said inner recess;
• a first laminate layer wrapped around said inner portion and said middle portion of said core element;
• and,
• said core element with said first laminate layer wrapped around said inner portion and said middle portion being inserted into said inner recess with said inner portion such that said first laminate layer is arranged between said core element and said bushing runout.

A method for manufacturing a laminate structure for a flange connection of a wind turbine rotor blade, the method comprising:

• providing a bushing, the bushing defining, at a first bushing end, a bore hole with an inner thread configured to accommodate a connection bolt, and, at a second bushing end, a bushing runout defining an inner recess, wherein the inner recess is funnel-shaped;
• providing a core element having an inner portion, a middle portion, and an outer portion, wherein the inner portion has a shape corresponding to the shape of the inner recess and the outer portion tapers at an end opposite to the inner portion;
• wrapping a first laminate layer around the inner portion and at least a part of the middle portion of the core element;
• inserting the core element into the inner recess with the inner portion such that the first laminate layer is arranged between the core element and the bushing runout;
• and,
• infusing the first laminate layer with resin and curing the resin.