Right Time, Right Size

Aug. 19, 2009
The wind energy market offers particular opportunities for forgers, and for one machine builder with a specialized ring-sizing technique.

One of the handful of industrial markets to offer manufacturers any encouragement in the past two years has been wind-energy, and the opportunities there include numerous openings for forgers and their products.

Forged components are critical to wind turbine construction and efficient operation. Seamless rolled rings used in many wind turbine designs measure up to 6 meters in diameter, and may weigh as much as 13 tons.

Radial ring expanders specially developed by a Dutch manufacturer are drawing attention to the particular processing demands of these products. “The deformation is obtained by overloading the metal ring beyond the elasticity limits,” explains Fontijne Grotnes. “The part to be expanded is positioned around the outer periphery of the forming dies. By the movement of the cone the dies are pushed outwards and stretch the metal part beyond its yield point.”

Fontijne Grotnes expanders are widely used by forgers for sizing rings of all dimensions and materials, to achieve tight tolerances for internal diameter and ovality. The Fontijne approach measures the ring inside diameter during and shortly after expansion. (The method also can be used to measure the still-hot ring after the expansion stage.)

By maintaining tight tolerances and product consistency, the method helps to reduce machining and saves production time and material costs. In mechanical terms, the technique makes it possible to produce rings that exceed material strength by up to 20%.

For wind turbine production, Fontijne Grotnes offers an expander for sizing seamless rolled rings used for slewing bearings. These essential components allow the turbine to rotate efficiently while remaining in line with the wind. Other applications for seamless rings in turbine design involve the blade bearings, yaw bearings, tower flanges, and wind gearboxes.

Fontijne Grotnes is marking its centennial anniversary this year. The company also produces other metal forming equipment, such as expansion and shrinking machinery, roll formers, special forming equipment for domestic appliance drums, and a wide range of equipment used to produce wheel components, pipe, nuclear reactor parts, and platen presses. It states that “craftsmanship, commitment, and the ability to innovate” are its core value, and credits the technical knowledge of its employees along with its 100 years’ experience for the quality of its products and services.