We4Ce, a Dutch supplier of rotor blade bushings, has filed an international patent for its Re-FIT bushings for on-site repair in wind parks. With the new repair method, the rotor blade is dismounted and repaired on-site. The damaged bushings are extracted and replaced using precision machining. The patent covers the bonding method and design.
An inlet tube placed into the hollow of the bushing infuses epoxy resin into the extremities of the bushing where a proprietary steel resin dispenser has been fixed. The resin is then evenly distributed around the outside of the bushing using vacuum processing, allowing the bonding material to flow uniformly up towards the flange of the bushing. The chosen diameter of the circular dispenser aids in the centring and precise placement of the component.
According to the company, the solution becomes viable for wind parks with more than ten damaged blade roots. This calculation includes the setup costs and use of a specialised CNC on-site machine for drilling out the damaged inserts.
