Due to the "air cooling" mode, water cooling channels, water cooling filters and other equipment are reduced, occupying less space, and the maintenance rate is lower, further improving the production efficiency. "We used a 90kw motor before, and there was a situation where the overpressure material could not be started. After the manual unloading starts, it is manually loaded. At present, Jiaxuan 75kw permanent magnet roller is used, which has excellent heavy-load starting performance. The first application of Jiaxuan permanent magnet roller in Kailuan, from February 20 18 to the present maintenance 15000 hours. According to the feedback from the field staff, eight bearings were changed to two bearings, which reduced the maintenance and greatly improved the energy saving rate of the 3 15kw dual-drive permanent magnet drum.