The first gearless drive system for a conveyor outside Germany, says ThyssenKrupp, will be part of the order to deliver an overland conveyor system for Xstrata Copper’s Antapaccay mine in Peru. ThyssenKrupp commissioned the Siemens Industry Solutions Division for the supply of the electrical drive system. In comparison to conventional drive solutions, these gearless drives have not only a higher efficiency, availability, and reliability, but also lower maintenance requirements. The conveyor system is due to be commissioned in 2012.The overland conveyor at Antapaccay will transport copper ore over a distance of some 6.5 km from the mine to the processing plant. The belt will be 1,372 mm wide, travel at 6.2 m/s, and is designed to transport about 5,260 t/h of material. The Siemens drive system for the overland conveyor comprises of two slow- speed synchronous motors – each with a total power of 3,800 kW – and the associated Sinamics SL150 cycloconverters. Each motor is connected directly to the drive pulley.This gearless drive solution has a number of advantages over the combination of high speed motor and gearbox usually used on conveyor systems. The size of the motor is not limited by the size of gearbox available, thus eliminating the necessity to install multi-motor drives. The power required to drive a belt can be provided by just one drive per belt pulley. This enables the size of the electrical room to be reduced, saving space and weight.The elimination of a whole series of mechanical and electrical components increases the reliability and efficiency of the overall system by between 3 and 4%. The maintenance requirements of the drive system are also substantially lower. Gearbox maintenance work alone can amount to up to 5% of the original investment volume – each year. Lubrication and gearbox cooling systems, together with their maintenance, are also obsoleted for this solution.The gearless drive system for the Antapaccay mine overland conveyor system is the second of its type. The first conveyor system to run with gearless drives was installed in 1986 by ThyssenKrupp (formerly O&K) and Siemens in the Prosper-Haniel mine belonging to Deutsche Steinkohle, and it achieves an availability of over 98%.