KAPP NILES KNG 12

The KAPP NILES KNG 12 is a CNC profile gear grinding machine from KAPP NILES GmbH & Co. KG, engineered for the production grinding of large external spur and helical gears in the mining, steel, cement, energy, and heavy industrial gearbox sectors. The KNG series represents KAPP NILES' capability at the large end of the profile gear grinding spectrum, with the KNG 12 accommodating gears up to approximately 12,000 mm (12 meters) pitch diameter — among the largest gear grinding capacities available from any manufacturer worldwide.

KAPP NILES is headquartered in Coburg, Germany, and is part of the KAPP Group, which has produced precision gear cutting and gear finishing machines since 1953. The company operates across the full spectrum of gear manufacturing technology — from small-diameter high-precision CBN grinding for automotive transmissions to large-capacity profile grinding for industrial giants. The KNG series occupies the top of this capability range, serving the segment of industry that requires hard finishing of the largest gears manufactured: mill drives, kiln drives, marine reduction gearboxes, large wind turbine drives, and heavy industrial planetary gearboxes.

Profile gear grinding — the process used by the KNG 12 — uses a formed grinding wheel whose cross-section matches the tooth space profile of the workpiece gear. The wheel is plunged or traversed into each tooth space in sequence, with an indexing rotation between teeth. For very large gears, this sequential process is practical because the alternative (continuous generating grinding with a worm wheel) becomes mechanically impractical at diameters above approximately 2-3 meters. The KNG 12 uses highly accurate CNC-controlled multi-axis motion to position and traverse the grinding wheel precisely through each tooth space, with dressing cycles maintaining the wheel's profile between operations or between teeth as required.

The machine operates on a table-and-column architecture appropriate for gears of this size — the workpiece gear, which may weigh tens or hundreds of tonnes, is mounted on a large rotary table while the grinding column traverses the tooth flanks. CNC multi-axis control coordinates grinding wheel feed, dressing, workpiece rotation (indexing and slow-roll for tooth profile generation), and coolant management. KAPP NILES' WOP-based control allows gear parameters to be entered directly, with automatic program generation for the grinding cycle.

The KNG 12 is a highly specialized machine serving a small but technically critical market: the manufacturers of the world's largest precision gears. These include manufacturers of ball mill and SAG mill ring gears for mining and mineral processing, kiln drive gears for cement and lime production, sugar mill drive gears, large marine reduction gearboxes, and the main drives for large ship engines and propellers. For these applications, there is no alternative to large-capacity profile gear grinding — the gears are too large for any other hard finishing process — and KAPP NILES' KNG series is one of a very small number of machines worldwide with the capacity to perform this work.