Modern Mining February 2024

ENERGY SOLUTIONS

SA mine gets world-first planetary gearbox customisation from SEW-EURODRIVE When a mining operation in South Africa’s Mpumalanga province found that one of its plan etary gearboxes on a high-torque conveyor was failing, it called SEW-EURODRIVE for a solu tion. Leveraging the latest intelligent technology, the solution is a pioneering innovation providing a cost-effective replacement that will ensure reliable performance. Greg Lewis, Business Development Manager Projects for SEW-EURODRIVE, says the application at the mine demanded a customised and carefully considered approach.

“ T he application itself was in the plant where a steel-belt transfer conveyor moves extremely slowly – with the 4 metre diam eter head pulley turning just one revolution every 25 minutes,” says Lewis. “Two planetary gear boxes drive the pulley, with one on each side, and the mine had been facing the pending failure of one of these, which needed to be replaced.” With the original installer of that gearbox unavail able, the mine came directly to SEW EURODRIVE, he explains. The drive specialist already has a good relationship with the mine and has provided most of the power transmission items on the site. “One of the key challenges was that the mine required only the one gearbox to be replaced at that stage,” Lewis says. “It is important to understand that in this application the two gearboxes must run together at the same speed and torque. Any varia tion in the speeds is not an option.” SEW-EURODRIVE was able to match one of its units very closely with the unit being replaced, but there was still a very slight difference in the ratios.

This led to a 0,001 difference in the revolutions per minute.

“While this may sound insignificant, it makes a difference when the gearbox torque is a couple of hundred thousand Nm’s,” he says. “At this high torque level,

Greg Lewis, Business Development Manager Projects for SEW EURODRIVE.

any misalignment or desynchronisation can affect the foundation and potentially cause catastrophic failure.” With the expert input of one of SEW-EURODRIVE’s in-house mechatronics engineers, the solution uses the company’s MOVI-C technology in a way that has never been done before. The new plan etary gearbox supplied by the company will match the torque of the original gearbox – ensuring that they turn at precisely the same speed. The solution involves removing the existing base plate and providing a new, drop-in solution with an SEW-EURODRIVE planetary gearbox – designed to match the current infrastructure in the plant. “The technology on our planetary gear box constantly changes the torque to match the existing equipment,” he said. To prove this intelligent design, SEW-EURODRIVE built a small-scale working mock-up for the customer to witness. Together with its own customised base-plate, the ‘model’ arrange ment was taken to site and demonstrated to the customer’s satisfaction. The mock-up was so successful that SEW-EURODRIVE colleagues around the world asked to see it, so they could learn from the achievement. It was also a show piece at the company’s exhibition stand at the 2022 Electra Mining Africa event just outside Johannesburg. Lewis explains that the project was

SEW-EURODRIVE leveraged its extensive experience to provide a world first planetary gearbox customisation to a local mine.

28  MODERN MINING  February 2024