Centrally-driven ball mills adopts large-sized double-row self-aligning roller bearing instead of Babbitt alloy bearing with lubrication. After technical improvement, bearing service life becomes longer, sealing becomes better, convenient disassembly and cleaning, and equipped with manual timing refuel, bearing is in good lubrication condition, is much simple and reliable than sliding bearing lubrication system. Considering the production load, the bearing is large size bearing, its capacity is much higher than ball mill at full load condition, so under normal circumstances, bearing service life is longer than mill equipment. Double-row self-aligning roller bearing reduces the friction resistance and static resistance, moreover, with the hydraulic coupling and gear wheel accelerator, power consumption fall by 10.7% – 40.5% than conventional grinding machines, energy saving effect is remarkable. Only with energy-saving, within two or three years you can recover ball mill input costs.