ROURKELA, SEP 4
The Dynamic Quality Circle (QC) group of the Plate Mill Department at Rourkela Steel Plant (RSP) has effectively addressed and eliminated delays caused by failures of the Groove Roll Gearbox Bridge. Their innovative project, titled “Elimination of Delay Due to Groove Roll Gearbox Bridge Failure,” has led to significant improvements in operational efficiency.
The Plate Mill depends on 12 groove rolls to feed slabs into the mill: 8 rolls on the entry side, including 1 idle roll, and 4 rolls on the delivery side. These rolls are powered by three gearboxes. The Dynamic QC group pinpointed Groove Roll Gearbox-2, located near the mill’s work roll, as particularly prone to failures. The bridge supporting the gearbox’s output gear train often cracked at the welded joint due to uneven load conditions from the mill. These failures damaged both input and output gears, resulting in substantial delays of 10 to 12 hours to restore the gearbox to operational status.
Upon investigation, the Dynamic QC group — consisting of SK Swain (Deputy Manager and Facilitator), JC Bisoi (MOMT and Group Leader), K Berik (OCT, Deputy Leader), RP Hembrom (OCT), SK Behera (Operator), S Sahoo (ACT), and Anand Ekka (ACT) — discovered that while the outer sides of both bridges inside the gearbox were welded to the walls, the inner sides lacked vertical support.
To address this issue, the team fabricated and welded two 20 mm thick plates into the blank spaces between the bridges. These plates were vertically welded to the bridges and the bottom of the gearbox, effectively transforming the two separate bridges into a single, robust structure. This modification ensures that uneven loads from the mill are now evenly distributed between the bridges, preventing the stress points that previously caused weld cracks.
This innovative initiative has completely eradicated delays due to bridge failures, significantly.
