Gears play a key role in our society today. Whether in modern automatic gear systems with eight or nine speed transmissions or in energy technology – when it comes to translating power into motion or motion into power, gears are the decisive components.
Gears are manufactured in various processes. But when it comes to producing large volumes of high quality fast and efficiently, hob cutting is simply indispensable. The history of hob cutting is closely linked with development at LMT Fette. In 1916, the enterprise established by Wilhelm Fette in Altona manufactured its first hob cutter. Since then, gearing experts at the company have continued to develop the latest technologies of hob cutting in the form of numerous innovations. On the occasion of our 100th anniversary, we would like to share with you an insight to our past developments, our present solutions and our future activities with these highly impressive tools.
160 years ago, Christian Schiele developed the continuous gearing process in England. He was way ahead of his time. Gearing machines were not used in industry until toward the end of the 19th century.
Wilhelm Fette manufactures his first hob cutters in Hamburg-Altona. They are already available for all module sizes M1 through M30. The workshop employed twelve people at this stage.
Wilhelm Fette grows to 500 people. A focus is attributed to the manufacture of hob cutters. The worldwide boom created by the automobile industry in particular leads to a huge demand for gear wheels.
Wilhelm Fette extends its range to studded hob cutters with teeth made from high-quality steel (High Speed Steel, HSS) are available for smaller modules. Cutter disc hobs are used for larger modules. They feature integrated supporting teeth and HSS teeth ensuring improved performance.
Wilhelm Fette is the world’s first tool manufacturer to receive a patent for toothing hobs whose special toothed profile reduces the cutting force, thereby increasing the running smoothness displayed by the cutter. By now, more than 1,000 people are employed by Fette.
Apart from HSS, Fette also offers hob cutters with brazed carbide tips for the first time. Environmental challenges are meanwhile demanding alternative energy sources thus giving rise to a new area of application: Wind Power Generation. Modern wind turbines are tested in various designs, adding a new requirement to large-module gearing.
Fette protects its HSS hob cutters from abrasive wear in the form of the first patented titanium nitride coating (TiN). Fette also registers another patent for a segmented hob cutter with inserts. It later evolves to become the Gear Runner External.
LMT Fette – member of the new founded LMT – launches the world's first coated hob cutter made of solid carbide. With an extensive tool life and cutting speeds, it is particularly suitable for large-series production in automobile production.
The requirements on efficient production are also increasing in the area of large gears, e.g. increasingly larger gear wheels for wind turbines, for which LMT Fette further develops the Gear Runner External. Thanks to a helical indexable insert solution, the machining process is smoother as it enters and exits the workpiece and indexable inserts create an improved efficiency in both tool changes and they are more user friendly.
The further development of combining three processes into one system continues to address the customers’ requirements. The ChamferCut process system patented by LMT Fette, makes it possible for the first time to perform the pre-milling, deburring and final-milling steps in a single operation. This shortens the manufacturing process, improves the customers production efficiency and provides more uptime on his machines driving cost out of his process.
In order to achieve longer tool life, LMT Fette develops the world's first nanostructured multi-layer coating for hobs in the form of Nanosphere.
As developments continue, the introduction of a new industrial standard takes place. Speedcore is introduced to the market. LMT Fette offers a new type of cutting material which permits up to 70% faster cutting speeds than HSS. This is due to the composition of the cobalt-molybdenum material which displays extremely high heat resistance thanks to special nanostructures.
LMT Fette launches Gear Runner Internal. The world’s first indexable insert hob cutter for internal gears. In terms of coating, Nanosphere 2.0 represents a new generation which further improves tool lives by up to 40%. The LMT Group also opens a global manufacturing facility for the production of hob cutters in Pune, India.
The SpeedCore hob cutter becomes more widely accepted with its improved performance characteristics. It is also available for large modules and can be fitted with the new High Temperature (HT) high-performance coating. Production has begun in an outstanding manner in Pune. In a mere 16 months, our Indian colleagues have already manufactured 10,000 hob cutters for customers around the world.
Engineering developments have already begun on the next level of performance. Designers at LMT Fette are working on the next generation of performance enhancing solutions for hob cutters. The new products will be presented for the first time to the international public at the AMB in September.
The industrial standard for gear cutting
Cutting internal gears
External gearing of maximum efficiency
Gear cutting and deburring in a single step
Reprocessing in manufacturer quality