Continental engineers used an optimal combination of two tried-and-tested timing belt technologies to develop the belts. Back in 2018, the company invested around 2 million in a new facility at the site in Lower Saxony to meet the Chinese company’s annual demand for over 100 kilometres of drive belts.
An efficient alternative
Goldwind is one of the few providers in the market to use a drive without a gearbox to adjust the blades, which is becoming vital to be able to respond flexibly to changing wind strengths. “Goldwind relies on timing belts,” says Rolf Marwede, who heads Continental’s location in Dannenberg. “There are some advantages to this. For instance, the system is less complex and therefore less prone to vibrations and disturbances at the top of the nacelle. Our belts are also extremely low-wear and durable.”
The belts do not require any oil for lubrication and are very low-maintenance overall and also largely corrosion-resistant. In offshore wind turbines in particular, this last point presents a major advantage over conventional metal designs that are permanently exposed to salty sea air. “In comparison with gearbox solutions, a simpler design that uses drive belts is also more cost-effective and more efficient in the long term,” Rolf adds. If there is a defect, the system can also be repaired very quickly because only the belt needs to be replaced, not the whole gearbox.
The best of two worlds
For Goldwind, it was important to develop a low-maintenance and simpler alternative to the conventional gearbox system. The chosen belt solution was an exact match for these requirements and is based on Continental’s Synchrodrive technology. Galvanized steel cords are integrated into the belt’s interior and coated with polyurethane, which furnishes both the teeth and the back of the belt and forms an outstanding connection with the tension member. Polyurethane is particularly abrasion-resistant.
The two opposing impact directions of the steel cords and their strands result in neutral running properties, making the belts extremely resilient. It is not uncommon for there to be around 12 million reverse bending cycles. But what makes the belts used by Goldwind so unique is the special fabric, which is manufactured at Continental’s location in Northeim. The drive belts make use of Synchrochain technology expertise for this application.
“The fabric reduces wear and absorbs noise and also provides a much more stable structure for the timing belt. This enables us to significantly improve the belt’s performance yet further,” explains Rolf. The fabric reinforces the teeth and improves run-in behavior, which in turn boosts efficiency. “Ultimately, we have brought together two product groups to develop the ideal solution for Goldwind’s application.”
Future production expansions
Continental manufactures the belts for Goldwind at its Dannenberg site, which is a competence centre for the production of polyurethane belts within the company. The technology company installed a new facility for this very purpose last year. The hall out of which the facility operates, which was newly built in 2017, offers space for further production expansion.
“At a single location, we can not only offer Synchrodrive and Synchrochain belts, but also combine both product types with each other such as for Goldwind which has never been done before.”
Other energy sources
In addition to drive belts, the company supplies the wind turbine manufacturer with mounting elements, films for reducing wind resistance, and hydraulic lines.
Wind is an unlimited resource. Wind turbines are considered clean, with the wind power they provide being the ideal complement to other energy sources. By the end of 2019, wind turbines with a total output of around 650 gigawatts had been installed around the world. By way of comparison, 40 gigawatts would be enough to supply electricity to every household in Germany. With installed power of well over 200 gigawatts, China is by far the world’s largest wind market.
Continental develops pioneering technologies and services for sustainable and connected mobility of people and their goods. Founded in 1871, the technology company offers safe, efficient, intelligent and affordable solutions for vehicles, machines, traffic and transportation. In 2019, Continental generated sales of 44.5 billion and currently employs about 240 000 people in 59 countries and markets.
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