Periodically inject grease of slewing ring rail. General ball bearing once every 100 hours refueling operation, roller bearing oiling every 50 hours, special working conditions, such as tropical, high humidity, dust, large temperature difference and the continuous work, should reduce the cycle of the lubrication. Machine shut down for a long time before and after must also infuse new grease. Filled with grease lubrication, always roll tao, until oozes out from the sealing tape. And in filling grease, slowly turn the rotary bearing, the grease filling evenly.