March 2022: During a planned gear unit inspection in hot rolling mill #2 at thyssenkrupp Steel Europe in Duisburg (Germany), several areas of damage were discovered on the spur gear of the output shaft on the over 90-ton main gear wheel set in finishing stand F2. There were indications that the gear unit was at risk of failing any time soon.
Only five months later, the SMS technical service team delivers a brand new wheel set – to the complete satisfaction of thyssenkrupp Steel Europe.
"What we have just seen is a remarkable team effort! On behalf of all the works staff, I would like to express my thanks for the consistently excellent and friendly collaboration. A gear unit failure would have caused significant supply bottlenecks for our internal and external customers. Every step of the way, the SMS group team members demonstrated a high degree of focused, professional expertise. The analysis and manufacturing opportunities that SMS group offer are impressive. They really helped us all – from our colleagues in the various business management teams to the mechanics in the production and shipping units," says Matthias Römer, Lead Engineer, WBW2 Machinery and Equipment at thyssenkrupp Steel Europe.
Every step of the way, the SMS group team members demonstrated a high degree of focused, professional expertise. The analysis and manufacturing opportunities that SMS group offer are impressive.
When arriving on site, the SMS team was able to verify the damage to the output gear wheel on the two-stage main gear unit that tkSE had discovered previously. The side plates had cracks, and the rim toothing had broken off at various points. The very same day, the team started work on a strategy to stabilize the defective gear unit as quickly as possible and so maintain production in the hot rolling mill, because a prolonged shutdown would have been unavoidable due to the lack of spare parts.
The detailed FEM (Finite element method) analysis of the old wheel set provided information on its structural stability. By changing the rolling parameters, and precisely monitoring and continuously analyzing the data from the Genius CM® Condition Monitoring System, it was possible to continue production of the high-quality steel grades rolled in the finishing train at thyssenkrupp Steel Europe.
Within the first five days, the SMS experts developed an engineering concept to manufacture a new output shaft as quickly as possible from available raw material as well as bar material that can be provided at short notice. In addition to a one-to-one replacement of the output shaft, a concept was developed in close cooperation with the customer to offer a complete wheel set as a more effective overall solution. The complete wheel set in SMS group's advanced gear design is capable of transmitting higher torques and thus meets the future requirements of tkSE.
"Without the existing raw materials from our raw materials store, we could never have helped thyssenkrupp Steel so quickly. Manufacturing the wheel set was a team effort involving colleagues in sales, engineering, purchasing, the Hilchenbach workshop, and field service. Huge compliments go to the various teams who did everything they could to get this 90-ton wheel set manufactured in such a short time," adds Patrick Vetter, Project Manager, Service Drive Technology, commenting on the success and commitment of the SMS team.
In just five months, SMS group supplied a complete, more powerful gear set in the SMS group advanced gear design. SMS group also provided assistance during the installation of the wheel set. For optimum power transmission, the contact pattern of the gear set was adjusted by SMS experts on site, and the gear unit was put into operation on schedule.