Rotary bearings are generally single-ring seals, but also multi-ring seals. On the one hand, the seal of rotary bearings is to prevent grease from leaking out. On the other hand, it is to prevent dust, impurities and water from intruding into the bearing and affecting its normal operation. Because the slewing bearings mostly work under heavy load and low speed, the sealing type of bearings adopts two kinds of structures: rubber seal ring and labyrinth seal. The rubber sealing structure has been widely used because of its simple structure, small occupancy space and reliable sealing performance, but its shortcoming is that the rubber sealing lip tends to age early and lose its sealing property at high temperature, so labyrinth seal is suitable for slewing bearing working at high temperature.
In the course of using, the sundries on the surface of the slewing bearing should be removed frequently, and the sealing strip of the slewing bearing should be checked whether it is aged, cracked, damaged or detached. If one of them happens, the sealing strip should be replaced in time to prevent the loss of sundries and grease entering the raceway. After replacing, the corresponding grease should be applied to avoid rolling body. And raceway lamarcation dead or rust.