Machining solutions for the wind power sector

A machining and drilling centre for very large blades

JATORMAN and IK4-TEKNIKER are designing and developing a machine that shortens the duration of high precision machining operations involving wind turbine blades measuring up to 75 metres in length.

The wind power sector is very demanding and dynamic. Emerging technological developments are aimed at reducing manufacturing costs and extending wind turbine service life.

This trend has made it necessary to develop more powerful wind turbines to increase energy capture in locations characterised by average or even low wind intensities.

Higher power ratings in wind turbines, however, require taller towers and bigger blades.

To meet current market demands, therefore, companies must apply automated solutions to wind turbine assembly lines and focus more on manufacturing larger blades.

It must be pointed out, however, that the production of larger blades (measuring over 60 metres in length with maximum 4 m inner diameters) means more manufacturing difficulties will be experienced in terms of handling and accuracy.

To address this challenge, the Navarre-based engineering firm JATORMAN (specialised in handling and moving large and heavy loads) and the IK4-TEKNIKER technology centre have jointly developed a solution to design and build an innovative machine for the drilling and machining wind turbine blades.

This solution stands out because of its speed, versatility and resilience to accommodate elements of different sizes. Consequently, the equipment can automatically machine parts with a maximum length of 75 metres in length and an outer diameter of 4.2 metres with a degree of accuracy that is 40% higher than levels reported nowadays. On the other hand, machining operations can be shortened by up to 60% compared to other systems currently in use.

It is within the framework of this collaboration that IK4-TEKNIKER has carried out a study aimed at implementing a viable automation solution capable of meeting all the necessary requirements.

The organisation has also been responsible for running a simulation and sizing, 3D mechanical design, electrical design and programming.

IK4-TEKNIKER and JATORMAN researchers, moreover, have developed a pilot solution comprising a sloping base, mobile turret, rotating shaft and an arm support. These arms are two welded structures that move linearly and allow adjustments to be made according to the size of the blade and the diameter to be machined.

To the end of each arm are fitted milling, radial and axial drilling fixtures that are also equipped with a laser sensor to measure and position the blade.

IK4-TEKNIKER has opted for measuring sensors based on optical principles to measure objects without any physical contact.

A risk analysis was also performed prior to the electrical design by selecting all the elements needed to fully guarantee safety for the operator and the machine.

By using a specific type of software, the technology centre can also deliver the coding required for the controller's programme and the user's screens.

IK4-TEKNIKER and JATORMAN have worked together to commission the machine at the latter's facilities and set up the entire training scheme for technical staff.