Lubricating grease should be added regularly to the slewing bearing. Add once for every 100 hours in operation for ball type slewing bearing; while for roller type slewing bearing, it should be added once for every 50 hours in operation. For special working environments such as tropical areas, dusty areas and places where the temperature is very different or it works continuously, lubricating cycles should be shortened. New lubricating grease must be added adequately for a machine before and after being long-term out of use, and each time it must be filled fully when pouring lubricating grease, until it leaks from sealing place. The slewing bearing must be rotated evenly when pouring lubricating grease, so as to make it be packed evenly. Keep the tooth surface of the slewing bearing clean, often remove the greasy dirt on the tooth surface and apply new lubricating grease. The pre-tightening force of the bolt must be checked after the slewing bearing is operated for 100 hours and once for every 500 hours afterwards, so as to keep enough pre-tightening force for the bolt. The operation situation of the slewing bearing should be observed constai1tly in use and it must be stopped immediately if abnormal noises, striking, sudden power increasing are found, so as to remove fault, and dismantle and examine if necessary. lt is prohibited to rinse the slewing bearing when it is in use, so as to prevent water from entering into the rolling track of the slewing bearing, and hard objects are prohibited to be put close to the intermeshing area of the gear. Often check the sealing condition of the slewing bearing. Sealing tape should be changed in time if it is damaged, so as to prevent foreign objects from entering into the inside.