Rolling steel is a tough process, the rolling machines being subjected to aggressive conditions such as high temperatures, severe mechanical impacts and permanent contact with water. The machines need, therefore, to rely on high technology, highly resistant components to withstand the tough working conditions, and avoid the unplanned production outages that result in financial losses. For example, Gerdau’s steel mill produces 12- thousand tons of rolled steel per month, an unexpected 2- hour interruption in the production process, would result in the loss of 120-tons of rolled steel.
Unfortunately, production outages were a common problem for GERDAU, as the majority of motors installed in the plant were quite old and did not provide the necessary features to sustain reliability. In particular, the motors were not equipped with adequate shaft sealing systems. This allowed water to penetrate into the motor bearings, shortening their life.
To solve this problem, the existing motors have been replaced by new, high technology Roller Table motors, designed and manufactured by WEG based upon Gerdau’s requirements. These motors ensure higher productivity, improved efficiency and deliver lower maintenance costs.
The Roller Table motors are designed with features that enable them to operate with complete reliability, despite contact with corrosive agents, such as water, steam, dust, high temperatures, and despite being subjected to a high number of start-ups and frequent rotation reversals. The features include radial fins, and IPW66 degree of protection, together with WEG’s innovative W3Seal sealing system for added protection against water ingress.
Since the Roller Table motors were delivered, in late 2008, they have proved themselves, performing reliably and fully meeting Gerdau’s expectations. As a result, Gerdau is benefiting from far greater certainty in its operations, because the company no longer faces the previous production shut-downs resulting from electric motor failures.