Optimising the “finishing touches”

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energy

Optimising the “finishing touches”

Wind power boom: thyssenkrupp rothe erde relies on optimised Starrag Dörries CONTUMAT vertical turning and grinding machine

Since 2008, thyssenkrupp rothe erde has received six Dörries CONTUMAT vertical turning and grinding machines from Starrag. Satisfied with the results, the world market leader in large-diameter anti-friction bearings, which are used in wind turbines, among other things, ordered the same model again – but with two modified and optimised supports.

Without them, many wind turbines would not be turning; these are large-diameter anti-friction bearings and rings from thyssenkrupp rothe erde, which are used in the drives of nine out of ten wind turbine manufacturers worldwide. The industrial company is continuously working on improvements in order to maintain and expand this leading global position.

Continuous optimisation and innovation are therefore part of everyday life, and thyssenkrupp rothe erde Germany GmbH in Lippstadt, which manufactures large-diameter anti-friction bearings, is playing an important role here. The finishing of the bearings is now carried out on seven Dörries CONTUMAT vertical turning and grinding machines.

Nine out of ten wind turbine manufacturers worldwide use large-diameter anti-friction bearings and rings from thyssenkrupp rothe erde in their drives.

“ The new Dörries CONTUMAT vertical turning and grinding machine fits in with the current trend towards ever larger wind turbines and thus larger anti-friction bearings.” - Hubert Erz

Designed for growth

In 2021, the company took delivery of a larger Dörries CONTUMAT VC 6300/500 MC F So, which has also proven to be an instrumental addition.

Dipl.-Ing. Hubert Erz, Senior Consultant Sales Renewables at Starrag: “Despite a fundamental satisfaction with the familiar machine concept, the experts in Lippstadt understand that new technological challenges require modifications.” The plant in Lippstadt therefore ordered the machine with some important new technical details that Starrag has improved.

For example, the portal of the machine is designed to be larger than is currently required. The newly installed base supports a base table which holds a magnetic chuck with a diameter of 5,000 mm. The base table can, however, be extended to 6,000 mm by means of ring segments, which allows it to support a larger magnetic chuck. “The machine can be adjusted in size,” explains Erz. “It therefore fits in with the current trend towards ever larger wind turbines and thus larger anti-friction bearings.” For future machines, there is even conversations of an extension to 7,000 mm.

Although the basic machine configuration corresponds to the predecessor model, the supports have been completely revised at the customer’s request. Starrag installed a new grinding support on the left with a centrally positioned motorised grinding spindle. Instead of a separate motorised drilling spindle, the turning/drilling support on the right-hand side was fitted with an integrated drilling spindle with HSK 100-A tool holder, which sits between the two turning tool holders from Kennametal. Customer advisor Erz: “We have designed the tool holder of the right-hand support in such a way that the modular size KM63 turning tools and the rotating HSK 100 tools can be picked up directly from a pick-up magazine, meaning an additional drilling unit is no longer required.”

Optimisation based on shop floor feedback

Feedback from operating personnel was also the impetus for numerous improvements. Starrag changed the dressing position, for example, to eliminate the previous bottleneck to the protective cover. Now grinding wheels of all types up to a diameter of 650 mm can be easily dressed on the left and right. “It is a significantly optimised, universal dresser,” emphasises Erz. “The multiple dressing positions allow operators to precisely adjust the dressing process to the grinding operation.” Another point of criticism concerned the machine enclosure. Starrag therefore commissioned a new manufacturer for the complete enclosure, whose construction and assembly, according to Erz, are distinguished by “the fact that the company delivers the enclosure ready for assembly and pre-tested and sets it up very efficiently”.

Focus on grinding support: Dr Matthias Töfke, Head of Series Production (left) at thyssenkrupp rothe erde, and his TB9 Operations Manager, Henning Brinkhus, in the working area of the new Dörries Contumat vertical turning and grinding machine.

“ The multiple dressing positions allow operators to precisely adjust the dressing process to the grinding operation.” - Hubert Erz

This optimisation was not only well received by management in Lippstadt, Erz reports after an on-site visit:“Machine operators Eduard Abt and Walerij Fabrizius, who have been using the predecessor machines for years, also responsed positive and satisfied.”