Roller Application: roller for a coal mine and the open air, coal preparation, etc. used in carrying on a belt conveyor idlers, return idlers and buffer roller. The main purpose is to support and drive belt, reducing the running resistance, resin roller mill, and the conveyor belt sag does not exceed a certain limit, the resin roller specifications to ensure the smooth operation of the conveyor belt. Roller life with a different structure, resin roller, which is why manufacturing, manufacturing factors in the calculation of roller life is often overlooked. Ensure bearing work under ideal conditions, is entrusted the responsibility of manufacturers roll manufacturing process should ensure concentricity error and idlers cylindrical roller bearing runout within the allowable range. Roller bearing clearance in the manufacturing process should not be overlooked.