In its final press release that reported on the successful conclusion of Husum Wind 2023, the organizer highlighted CNC Onsite’s precision flange milling service for 10-meter offshore wind turbine flanges. Only three wind turbine products were mentioned in the Husum Wind press report on innovations and other highlights. Wind turbine flanges are becoming larger with 8-meter flanges on the market. The tolerances between the two flange faces must be to within two millimeters. CNC Onsite’s solution can offer that precision.
Reported by the German Wind Energy Association (BWE) news portal Windindustrie in Deutschland (English: Wind industry in Germany), the news item details that CNC Onsite has partnered with We4Ce, a Dutch wind turbine rotor blade bushing expert, to jointly develop a blade root repair solution. The solution, which was presented at Husum Wind 2023, makes use of CNC Onsite’s mobile precision machine that drills out the damaged bushings and reinserts new replacement bushings, also called inserts, supplied by the Dutch partner.
Conducted onsite in the wind park, the repair service meets the need from wind turbine owners for efficient repairs that keep CO2 emissions at a minimum. Up until now, the whole wind turbine blade was transported for repair or was completely replaced. What is the cause of wind turbine blade root bushings damage? The article in German explains:
The Bundesverband WindEnergie (BWE) represents the wind energy industry in Germany and has more than 20,000 members.
North American Clean Energy is a printed magazine that reaches nearly 60,000 readers, most of them renewable professionals located in North America, including Canada. Covering CNC Onsite’s new blade root bushing repair service, North American Clean Energy focused on the logistics side of the story. Soeren Kellenberger, sales director of CNC Onsite, authored the article exclusively for the magazine, which explains the process of CNC Onsite’s blade root repair. The portable precision machine is aligned to the wind turbine blade and then drills away the damaged rotor blade bushings from the composite material at the blade root end. After that, an additional drilling process ensures that the new parts – the rotor bushings – can be inserted, precisely aligned with the previous insert. The rotor bushing is then fastened using bonding material. More information in the article, which also explains why root bushings at the blade root break.
The Fastener and Fixing magazine, an English language publication that reaches some 50,000 professionals in the fastener sector worldwide, including the wind turbine industry. The magazine included the launch at WindEnergy Hamburg of CNC Onsite’s world premiere, a wind park blade root repair service for damaged threaded inserts, sometimes called root bushings with threads, which are located at the root of the wind rotor blade and connects the turbine blades with the nacelle (the hub itself is connected to the turbine’s main shaft). The magazine reported that the threaded bushings, also called rotor blade inserts, are important for joining the blades to the hub. Over time, when blades are older, these can loosen. There are different reasons why threaded bushings of the wind turbine blade root connection can loosen and become damaged. One is microcracks that form and worsen over time and then allow contaminants into the polymer material.
Motion&Drives, an international power transmission and motion control magazine, reported on CNC Onsite’s invention – a blade root connection repair solutions developed with We4Ce. The technical engineering readers of the news portal were able to learn about the blade root repair solution, which offers precision drilling of damaged blade root bushings. The service is carried out on-site directly in the wind park itself. Normally the rotor blades would have to be sent to the blade manufacturer for repair which takes away important downtime if not to say waiting times. This saves logistics and also it saves on CO2 emissions. Transporting a rotor blade is also associated with high costs and special approvals. The solution offers cost-efficient repair of blade root connection damage, a problem older wind turbine can experience.
The news portal North American Windpower (NAW) informs likely 100,000s professionals in the wind energy generation and distribution sector in the North America. As NAW highlights technical product advancements, the story on CNC Onsite’s new precision machine called “Goliath” that can mill 10-meter flanges of tower bases, monopiles and transition pieces (TP). Offshore flanges require flange faces that are accurate to within two millimeters. This means the gap between the two wind turbine flanges must not exceed 2 mm.
The printed and online publication Windtech International explains technical advancements in a way that is easy to understand. CNC Onsite was invited by the publication to author a piece on its patented yaw ring repair service. The solution consists of two patents, one for the portable design of machine as it can be dissembled, and one for the actual drilling out of the damaged yaw ring teeth. The CNC precision machine was designed to work sideways, as there is not enough working space around the yaw ring. When the teeth break in a wind turbine yaw ring gears this can be problematic as the yaw ring is used to turn the rotor blades according to the wind direction. Broken yaw ring teeth means the wind turbine is not working as efficiently as it could. But repairing a yaw ring is complex, which is why in the past, before this onsite mobile repair solution was launched, the whole yaw ring was replaced. Such a procedure requires logistics, like cranes to remove the nacelle or transport of the new yaw ring. CNC Onsite’s new repair service is an alternative to replacing the whole wind turbine yaw ring. The article explains the technical process and the steps involved when repairing the yaw ring. Windtech International is a subscription magazine.
Windsystemsmag.com shows CNC Onsite’s invention for a yaw ring system that could extend wind turbine life, is how the portal reported the yaw ring repair solution developed by CNC Onsite. The article included a technical drawing from the patent, using it to illustrate where the yaw ring is located on a wind turbine.
Background: The toothed yaw ring is a gear that engages with various motors mounted on the nacelle to align the rotor blades with the direction of the wind. The causes of damage to the yaw ring gear teeth include unpredictable wind conditions but can also include uneven loads over a sustained period of time. Often several turbines within the same wind park are affected. This could mean that the wind park were affected by specific same events. Unfortunately, these cannot be predicted in advance.
The yaw ring is a crucial component for gaining maximum power production from a wind turbine, The yaw ring is sometimes also referred to as “yaw gear rim”. The yaw ring gear is complex to replace. The costs of a yaw ring replacement can be so prohibitive that owners of older wind turbines experiencing yaw ring gear damage instead decide to scrap the whole unit.
Windpower Engineering & Development is a news portal focusing on technical news for wind professionals. The news portal selected CNC Onsite’s repair method for inclusion on the main website www.windpowerengineering.com, highlighting its on-site merits, calling it an “in-turbine” method for repairing damaged teeth on a yaw ring gear. As many of the readers are professional wind turbine engineers and technicians, the portal underlined the partent associated with CNC Onsite’s yaw ring repair method. Also, the article stressed that it was a method “for repairing, not replacing” yaw rings on wind turbines on site. This emphasis is necessary, since the development was driven by the fact that damage to the teeth of the yaw ring gear often will end up in the replacement of the whole yaw ring gear. This would mean that the whole nacelle would be taken down, using cranes for example, which is a significant logistics exercise with high costs for the wind turbine owner.