Eickhoff is also a leader in the production of coking plant machines and locomotives through its subsidiary, Schalker Eisenhütte. It also manufactures a wide range of vendor parts at its own foundry. A further major pillar is gear manufacturing, where a strong position has been established in the manufacture of wind turbine transmission systems. Eickhoff Bergbautechnik GmbH specialises in the development, construction and manufacture of shearer loaders, continuous miners and roadheaders for mining and tunnelling.
In coal mining, the shearer loaders from Bochum work at the forefront of the coalface. A coal seam is divided into faces and the coal is then extracted from the individual sections. Where faceworkers previously operated, today it is the shearer loaders which cut and convey the coal. This type of machine is up to 20 metres long, 3.75 metres high and weighs up to 165 tonnes. It moves up and down the coalface on the conveyor. At the front end, the shearer loader has rotating cutting cylinders with chisels, which cut a coal strip out of the seam in a forward movement. The Eickhoff SL 1000 shearer loader with an installed total power of 2590 kW, can cut at a height of up to 7.10m. The recovered coal falls behind the cutting cylinder into the chain conveyor, on which the coal is continuously transported away.
Eickhoff does not only build high-performance shearer loaders. In 2010, the company received the BAUMA innovation prize for what is currently the most intelligent mining machine in the world. Efficient computers and communications systems as well as state-of-the-art sensor technology and infrared cameras, radar and vibration probes enable the Eickhoff SL 750 EiControlPlus shearer loader to identify underground obstacles and barriers between coal and surrounding rock autonomously. This has made it possible for the first time to realise the idea of an automatic longwall mining operation where workers can concentrate on monitoring functions in a safe environment.
Eickhoff mining machines are serviced worldwide by over 100 field service technicians. They are also on site when an Eickhoff loader is installed for the first time. A new shearer loader is initially assembled above ground at the customer and subsequently disassembled again. This allows employees to familiarise themselves with every detail of the machine. This can take up to two weeks and is followed by assembly below ground. Assembly at the coal face can take up to two weeks. Assembly ultimately depends on the local conditions as it is not always possible to transport the entire machine to the coal face. Sometimes, it has to be installed in individual units, which extends the assembly time. Before the shearer loader is finally put into operation, test runs are carried out and the machine is modified to suit the prevailing conditions if necessary.
In the start-up phase, the shearer loaders are monitored by Eickhoff service technicians and initial maintenance is carried out with the operator. The service technicians also provide technical support for subsequent maintenance if required or offer a maintenance service.
Experts with the necessary specialised knowledge provide mechanical and electrical maintenance on site. In countries such as China or Russia, the teams are further supported by interpreters. The operating instructions of the machines specify maintenance intervals on a shift, daily, weekly or monthly basis. Monthly maintenance requires about six hours and additional preparation time. The compulsory programme for this includes lubricant analysis for the gear and hydraulic oils.
The shearer loaders have gears for power transmission to the cutting elements and traction drives. Hydraulic oils assist operation of the supporting arms and canopy. High-temperature greases are used for the lubrication of electric motors and high-performance greases for bearings exposed to vibrations and water. Like other hydraulic equipment in underground mining, Eickhoff uses the prescribed fire-resistant, HFC hydrous hydraulic fluids. As the working conditions in mines are extreme, not least due to the high level of dust that needs to be contained with water, Eickhoff protects the hydraulic system against solids contamination with special filters. The systems are provided with return flow filters and pressure filters as well as a clogging indicator to show when replacement is necessary. HFC hydraulic oil change intervals depend on the duration of use and condition of the oil. Contaminants and wear particles play a crucial role, as does the necessary water content of the HFC hydraulic oil, which should be between 35% and 50%.
These and other significant parameters are reliably monitored at the OELCHECK laboratory with lubricant analyses typical for HFC oils. For timely analyses, samples mainly from European customers of Eickhoff are monitored by OELCHECK. Reference samples from other countries are also sent to OELCHECK time and again. These are carefully examined at the laboratory in Brannenburg, For the purpose of quality assurance, own laboratory results are often compared with the values of foreign laboratories or the values are re-examined by the diagnostic specialists at OELCHECK. This enables Eickhoff service technicians to assess the condition of lubricants and machinery worldwide in accordance with harmonised standards.
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