If a large amount of powder enters the internal bearing, the powder will bond with the ultrafine vertical mill lubricating oil and become a viscous and extremely poorly fluid powder-oil mixture. Not only will it not have any lubrication effect on the bearing, it will also increase the weight. The wear of the bearing makes the temperature of the roller bearing rise abnormally.When it is found that powder enters the inside of the bearing and causes an abnormal increase in the temperature of the bearing, the oil seal should be replaced immediately, and the quality of the ultrafine vertical mill lubricating oil should be reviewed to ensure that it has not deteriorated. If too much powder accumulates inside the bearing and the powder-oil mixture cannot be discharged with the oil outlet, the inner end cover of the bearing can be opened at this time, and the powder-oil mixture can be discharged by means of compressed air or hydrogen injection, and then refilled.