Abstract: Unreliable sealing will lead to lubrication failure of the roller, which results in quick rising of rotational resistance and even turning blocked, is one of the most important failure reason of the belt conveyor used in coal mine. In order to solve the problem of excessive rotation resistance and service life of the roller conveyor belt, a roller prototype is designed and manufactured on the basis of nano magnetic liquid seal and lubrication principles. The test was carried out under different conditions between the magnetic liquid sealed & lubricating (MLSL) roller and the traditional roller, to compare their working performance. The results show that under the normal environment and the determined load, the rotational resistance of the MLSL roller is reduced by 45% compared with the traditional roller, and the average reduction is 17%. Under the normal environment and the determined belt speed, the maximum reduction of rotational resistance of the MLSL roller compared with the traditional roller is 73%, and the average value is 54%. In the simulated underground coal dust environment, the rotational resistance of the MLSL roller is reduced by 26% compared with the traditional roller. After spraying by the coal slurry water for 24 hours, the rotational resistance of the traditional roller is increased by 7 times. However, the rotational resistance of the MLSL roller is substantially unchanged. It is proved that the roller with magnetic liquid sealing and lubrication structure has excellent performances such as low rotation resistance and high anti-water performance under different test conditions, which can provide powerful technical support for the development of low-energy, high-reliability and long-life roller for belt conveyors.

Key words: roller, belt conveyor, magnetic liquid, sealing, lubrication, rotational resistance