“uåX˜äŠÊ˜·³Ç

Gearboxes are one of the most critical components in a wind turbine, transferring power from the turbine's shaft to a generator. Roughly 80 % of modern wind turbines use gearboxes, making precision manufacturing essential to maximise power generation and efficiency.

Why precision grinding matters

Precision finishing refines the surface of the gear teeth, ensuring smooth and efficient meshing to reduce noise, friction, and premature wear. Grinding is the most reliable process for achieving the precise geometries needed for optimal gear strength and efficiency.

For wind turbines, planetary gears, ring gears, and sun gears require grinding to meet performance demands. Due to their size, discontinuous profile grinding is the only suitable finishing process.

Rising turbine sizes and gearbox challenges

Turbines with power capacities of up to 20 MW are now under development. Increased input torque places greater stress on gearboxes, leading to issues like pitting, scuffing, and wear—all of which can result in costly downtime and repairs.

According to Thalau (pictured right), high-precision finishing is key to improving efficiency and durability. “When designing grinding processes that approach the technological limit, it is important that all parts of the grinding process complement each other,” he explains.

Specialist support for gear manufacturing

Kapp Niles specialises in producing high-quality and economical solutions for finishing gears and profiles. These are machines for gear grinding and measuring as well as dressing tools, which enable gearbox manufacturers to refine their products to the highest standard.

Its product range is designed to work seamlessly together—a crucial factor given the complexity of the gear grinding process. For instance, surface quality depends on the grinding tool’s topography and how the grinding process is executed. 

By supplying optimised dressing tools alongside grinding machines, Kapp Niles ensures consistency in the finishing process.

“These solutions target the quality of the ground gears as they determine the reliability and performance of the entire turbine,” says Thalau.

Adapting to the energy transition

The global shift to renewables has increased demand for more efficient and durable wind turbine components.

However, simply scaling up gearbox size in proportion to turbine size is not feasible— for example, transporting such heavy components would be impractical. Larger turbines also exert significantly higher torque, requiring gearboxes with enhanced torque density, reaching values as high as 200 Nm/kg.

To address this, manufacturers are adapting the gear design, for example, by increasing the size of the gears or optimising material selection and heat treatment processes to improve load-bearing capacity. 

“To support our customers, we tightly monitor current challenges of the industry and initiate development of new products and solutions. In the context of the wind power industry, new solutions mainly target the quality of the ground gears as well as the productivity and cost efficiency of the manufacturing process.” 

Engineering innovation for future turbines

As turbines become larger and more complex, grinding and measuring solutions must evolve. However, technical challenges persist. For instance, larger ring gears require precise placement in grinding machines—a difficult task given their weight.

To address this, Kapp Niles has developed a machine-integrated wobble-compensation function. The system uses a measuring probe to capture the workpiece’s exact position, compensating for placement errors automatically.

The company also recognises the growing pressure on gearbox and turbine manufacturers to improve productivity and cost efficiency. Shorter grinding and setup times are in high demand, but reducing grinding times while maintaining or improving quality is a significant challenge.

Regarding automation solutions, Kapp Niles has introduced an automatic tool-changing system for its large-profile grinding machines. “An automatic tool-changing system allows the use of an optimised tool for roughing to remove bulk material, then switches to a specialised tool for finishing,” explains Thalau.

This approach enables the economic use of fine grinding tools with small grit sizes, achieving surface roughness values as low as 0.2 µm or lower.

When aiming for high precision in gear grinding, not only the grinding process and machine is of high importance, also the measuring technology is crucial. As measuring results need to be considered when setting up the grinding machine and technology, high accuracy of the measuring machine as well as reliable data exchange between measuring and grinding machine is essential. Kapp Niles plays a crucial role in this by providing gear measuring machines for components up to 6000 mm in diameter, ensuring the highest level of precision in production.

"Building our own measuring machines and software makes the exchange of measuring results with the grinding machine much more convenient and user-friendly,” says Thalau.

Trends in gear finishing and future innovations

Productivity, automation, and quality enhancement technologies—such as surface roughness optimisation—will continue to shape the industry. To address these challenges, Kapp Niles is also focusing on expanding its digital solutions, including process monitoring systems and technology assistants.

To support machine operators that are facing increasingly complex machining tasks, the company is also enhancing its user interface and integrating assistant systems to help design grinding processes and detect anomalies.

Additionally, to productively create large modifications on wind turbine gears, Kapp Niles is optimising functions for five-axes interpolated grinding to maximise feed speeds with precise geometrical accuracy.

By combining machine-integrated measuring systems with smart correction algorithms, the company aims to reduce costly rejections and improve manufacturing efficiency.

“To address future challenges in grinding applications for wind power parts, we expect that digital solutions, e.g. in the form of technology assistants or process monitoring systems will be a valuable tool. Furthermore, we are working on making the user experience as intuitive as possible, e.g. by providing user interfaces that allow easy configuration of even complex machining tasks.”

Looking ahead

As the wind industry continues to evolve, turbine gears must meet ever-increasing demands for efficiency and durability. Precision finishing is central to ensuring gearbox reliability and performance.

Kapp Niles leverages expertise across mobility, automation, and energy sectors, applying innovations from other industries to wind energy. Having supported the wind industry for almost three decades, the company remains committed to driving progress in turbine gear manufacturing for decades to come.

To learn how Kapp Niles precision gear grinding solutions can enhance your gearbox performance, please visit: