Practical test – Eco Gear in the bucket-wheel excavator

• 06 Jun 2015

The bucket-wheel excavator “288” was built by Krupp Industry Technologies in 1978. It is in use in the open pit Garzweiler of the RWE Power AG. Bucket-wheel excavator “288” and its 7 siblings belong to the largest excavators of the world. In autumn 2006 its gear was changed to the high-performance gear oil ADDINOL Eco Gear. So far the gear oil masters its practical test without any ifs and buts.

The bucket-wheel excavator mines 240,000 tons of brown coal or 240,000 m³ overburden every day. Its weight of more than 13,000 tons corresponds to the weight of 13,000 VW Golf. With 240 metres it is as long as two and a half football fields. The height amounts to 96 metres. The bucket-wheel itself has a diameter of 21.6 metres. 18 buckets dig into the ground and the coal. The large main drive of the bucket-wheel is filled with 2,800 litres gear oil. The gear rim of the large bucket gear wheel has 532 teeth in total.

The loads on the gear are enormous: pushes and vibrations as well as dirt, coal dust, varying temperatures and humidity. During a large inspection of the gear in September 2006 evident damages were discovered on the gear teeth – not unusual considering the loads but the extent of the damages was not harmless. Apparently the used gear oil was not up to the specific loads of the excavator. After detailed consultations between the RWE Power AG and the application technology of the ADDINOL Lube Oil GmbH the gear was changed to ADDINOL Eco Gear 460 M.

ADDINOL Eco Gear contains the active substance combination Surftec®. It adapts to changing load conditions in the toothing and prevents pitting and micro-pitting. The sharp edges of already existing pittings are rounded off resulting in a wear-free and friction-reduced run. Progressive metal abrasions are transformed into regressive ones.

In spring 2007 the next inspection was carried out. The condition of the tooth flanks had not worsened. The high-performance gear oil had passed its first practical test. Sharp edges of the old pittings had been rounded off; smoothening of the pittings had already started. The gear runs stable and trouble-free. To be on the safe side lubricant analyses are carried out in regular intervals – until today with positive results.

« înapoi la știri