World first planetary gearbox customisation

When a mining operation in Mpumalanga found that one of its planetary gearboxes on a high torque conveyor was failing, it called SEW-EURODRIVE for a solution. Leveraging the latest intelligent technology, the solution was a pioneering innovation providing a cost-effective replacement that will ensure reliable performance. Business development manager, Greg Lewis says the application at the mine demanded a customised and carefully considered approach.
The application itself was in the plant where a steel-belt transfer conveyor moved extremely slowly, with the four metre diameter head pulley turning just one revolution every 25 minutes,” says Lewis. “Two planetary gearboxes drove 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 the gearbox unavailable, the mine came directly to SEW-EURODRIVE. The drive specialist already had a good relationship with the mine, and had 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 had to run together, at exactly the same speed and torque. Any variation in the speeds was 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,” he explains. “At this high torque level, any misalignment or desynchronisation can affect the foundation, and potentially cause catastrophic failure.”

With the expert input of SEW-EURODRIVE’s mechatronics engineers, the solution used the company’s MOVI-C technology in a way never been done before. The new planetary gearbox supplied by the company matched the torque of the original gearbox, ensuring that they turned at precisely the same speed. The solution involved removing the existing base plate and providing a new drop-in solution with a SEW-EURODRIVE planetary gearbox designed to match the current infrastructure in the plant.

“The technology on our planetary gearbox constantly changed the torque to match the existing equipment,” adds Lewis. To prove this intelligent design, SEW-EURODRIVE built a small-scale working mockup for the customer to witness. Together with its own customised base-plate, the model arrangement was taken to site and demonstrated, to the customer’s satisfaction. The mockup was so successful that SEW-EURODRIVE colleagues around the world asked to see it.Solar Damper,Lithium battery,Solar tracker actuator,Solar Tracking Controller,solar energy system for home

The project was designed and delivered by SEW-EURODRIVE as a complete solution, from the fully customisable panels to the electronics and the installation of the gearbox. The installed unit was an XP planetary gearbox with a shrink disc, with a primary X-series gearbox as a further reduction unit to achieve the required ratio.

“We engineered the steel base to fit onto the existing concrete foundation, without any modifications required from the customer’s side,” he says. At about 1,7 m in height – and measuring 2,1 m wide and long – the gearbox itself was sizeable, weighing about 6 tons. Moving at 0,07 rpm, it moved the steel belt that carried a fine cake of raw chrome material.

“There are not many companies who can produce a solution to meet these very slow revolutions,” Lewis says. “This project has been particularly rewarding as it demonstrates our capability in matching another footprint, and eliminated the need for the customer to break down existing structures and build new ones.”Solar Damper,Lithium battery,Solar tracker actuator,Solar Tracking Controller,solar energy system for home

The unique requirements of the project meant extensive onsite engagement with the customer and detailed measurement of plant requirements. SEW-EURODRIVE’s engineers in Johannesburg generated the working drawings from which global counterparts within the group could begin manufacturing the unit in Germany.

The customer was so happy with this creative solution that its other plants may well be looking at similar replacements. “We are already assisting with our full service technicians, and we can provide experts in electronics, mechanical engineering and mechatronics, as the need arises,” he says. “The electronics in this solution will allow the mine to implement a range of enhancements in the future, including safety features and monitoring of operations.”Solar Damper,Lithium battery,Solar tracker actuator,Solar Tracking Controller,sol