VDMA

JAN-FEB 2018

Best of Germany 2014 - Mining Equipment and Mining Technology

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VDMA 17 2018 • VDMA MINING SUPPLEMENT In addition to increases in productivity, automation increased equipment availability and reduced in-panel parts usage, specifi- cally replacement of conveyor flights, shear pins and conveyor con- nectors, also known as dog bones. Over three panels, longwall sys- tem availability increased from 91% to 96.5%. The data collected, however, does not distinguish between mechanical availability and mine attributable delays, such as repair time and parts availability. The use of variable frequency drive (VFD) technology in long- wall applications is a recent trend that has already made a pos- itive impact on many installations. Using VFD technology and an innovative low-speed, high-torque motor, Caterpillar is working to step up longwall face conveyor performance even more. The permanent magnet synchronous motor (PMSM) combined with the VFD promises multiple benefits, such as higher productivity and reduced total cost of ownership through low maintenance and high mechanical availability. The drive system also features an extensive automation pack- age, programmable for the application. It can be adapted to special applications or geological situations (roof falls, geological faults, etc.). Because the torque motor delivers max torque at any speed, the automation system can adjust speed to optimize production, reduce electricity consumption, and minimize wear on components such as sprockets and flight bars. The automation system is combined with enhanced condition monitoring to make sure that the machinery is protected and can run at maximum output. All of the necessary data is linked to a database to support predictive and condition-based maintenance. The High Torque Drive system is built around the low-speed mo- tor, which delivers the same high torque at all speeds. The convert- er-controlled torque motor operates at speeds between 0 and 300 rpm versus 1,500 rpm for induction motors. Lower speed reduces inertia acting on the output shaft by a factor of eight and enables the system to react quickly, which translates to little or no damage to the gearbox and conveyor chain in the event of a conveyor blockage. In addition to soft start and stop, the High Torque Drive delivers very fast acceleration. The variable conveyor chain speed can be efficiently adapted to the production conditions — resulting in less wear on the conveyor. The system also is about 5% more efficient than conventional drives. The improved system efficiency means lower energy consumption and reduced cooling requirements. The new drive system consists of two main components — a variable frequency converter and the motor-gearbox combination. As compared to previous systems, a medium-voltage converter-con- trolled torque motor replaces the AC induction motor. The control principle of the drive is direct torque control — the most advanced AC-drive control technology available. High torque even at low speeds enables using only one gear stage, which results in smaller dimensions while retaining the same torque capabilities as systems that are as much as 20% larger. The low speed of the motor also reduces wear and extends service intervals. WE PROUDLY INTRODUCE OUR NEWEST PRODUCT EICKHOFF SL SHEARER SERIES Highest reliability combined with state of the art automation features make work at coal faces the most productive and safest ever. Eickhoff SL Shearer series represent the apex of longwall shearer technology. Even in difficult applications and harshest mining conditions, the most powerful and reliable solutions are attained through Eickhoff. We continually demonstrate why longwall operators rely on us. Experience has no substitute · Eickhoff since 1864 WWW.EICKHOFF-INTERNATIONAL.COM: AUSTRALIA · BELORUSSIA · CHINA · GERMANY · POLAND · RUSSIA · SOUTH AFRICA · USA In addition to soft starts and stops, Cat's High Torque Drive system reduces AFC wear.

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