Large slewing bearings are commonly found in large machinery and equipment, such as bucket turbines. During the production and operation of this kind of large-scale equipment that is not easy to move, due to a large number of working conditions, it is inevitable that parts will fail. The large slewing bearing is an important part of the bucket wheel machine, and the wear of the slewing bearing during work is common. A kind of failure, according to the understanding, share typical examples of wear failures of slewing bearings on bucket turbines, as well as bearing maintenance processes and related matters.

1. Wear condition of large slewing bearing
During the maintenance of the bucket turbine, the overhaul of the slewing bearing is an important part. During the overhaul, it was found that due to the poor condition of the lubrication system and the poor sealing condition, residues entered the bearing track, and at the same time, there were dots at the contact position of the rollers, and Circular wear marks.

2. Analysis of the causes of wear of slewing bearings
The large-scale slewing bearing in the bucket turbine has a relatively large load bearing strength, and long-term operation will cause great damage to the bearing. The reasons for the failure of the slewing bearing during the working process of the bucket turbine are probably as follows:

(1) The slewing bearing of the bucket turbine has been used for a long time, and there are some small problems in the maintenance process that have not been paid attention to. Over time, the accumulation of problems will lead to major failures;

(2) During the working process of the bucket turbine, the overhaul and maintenance of the bucket turbine were not timely, so that some minor problems in the working process of the bucket turbine were not reported for maintenance in time, and the maintenance and cleaning of the bucket turbine was not in place, which made the bucket turbine slewing bearing. There is a lot of dust inside, which affects the rotation of the bearing and causes the failure of the slewing bearing;

(3) During the transfer process of the bucket wheel machine, the overloaded transfer of goods will damage the working performance of the bucket wheel machine, thereby causing the work failure of the bucket wheel machine.

3. Maintenance steps of bucket turbine slewing bearing
For a large and difficult-to-handle mechanical equipment like a bucket wheel, when it breaks down and decides to overhaul, it must be prepared for the overhaul work. The bucket wheel is different from other small mechanical equipment, and the overhaul is not good. It can extend the time to continue the maintenance, it cannot leave the transfer work for too long, and the transfer work of the power plant and the wharf will face the threat of paralysis. In most cases, it is not practical to introduce a new bucket wheel , so the maintenance time can only be shortened, and the preparations before the maintenance should be done well.

(1) Preparations before maintenance of bucket turbine slewing bearing
First, the slewing bearing of the failed bucket turbine is jacked up by a hydraulic jack, so that the horizontal shaft of the slewing bearing can be pulled out for inspection and maintenance. When using the jack to lift the slewing bearing, pay attention to fixing the base of the jack to avoid serious accidents caused by the slewing bearing slumping due to the jack being skewed. Therefore, in the preparation process, the jack is fixed, and then a stable support or pier is established as required. The workpiece supported by columns, etc., must be guaranteed that after the bucket turbine is put into work, the built brackets and piers will not affect its normal operation. , which saves both cost and time.

(2) Carry out disassembly and maintenance work
After the disassembly process of the bucket wheel machine has been established, it is necessary to ensure that there is enough space around the maintenance to store the parts removed from the bucket wheel machine. 1. Remove the coal drop, central cable, and inner and outer protective covers of the gears of the bucket turbine and release the oil in the oil tank. Open the oil tank to disassemble the bearing bolts. Take out the slewing bearing through the workpiece created in the preparation work, and troubleshoot it. Analyze and then repair.

(3) Installation of slewing bearing
Install the repaired slewing bearing on the bucket turbine. Strictly check the connecting bolts of the inner and outer rings of the slewing bearing during the installation process. The bolts that do not meet the safety requirements must be replaced with new ones that meet the safety requirements. After installation, for the oil tank with thin steel plate, in order to ensure the toughness of the oil tank, try to replace it with a new oil tank after the oil tank is opened, because the welded oil tank is very prone to failure after long-term use, in order to avoid secondary failures Therefore, try to replace the oil tank with a new one to reduce the number of failures of the bucket turbine. When putting the installed bucket wheel machine into operation, it must be tested first, and then it can be put into work after passing the test.

4. Matters needing attention when the slewing bearing is overhauled
First of all, pay attention to the lubrication effect of the bearing raceway during the maintenance process of the slewing bearing. For a huge slewing bearing, if the lubrication effect of the narrow and long raceway is not good, not only the dust accumulated in the raceway will affect the operation of the bearing for a long time, and the rolling It is difficult for the lubricating oil added to the track to have the desired effect. In this way, even if the slewing bearing is repaired, when it is put into use, the bearing will be worn again due to the poor lubricating effect of the raceway. There will be failures, so we must pay attention to the lubrication and cleaning of the bearing raceway, pay attention to the method of adding lubricating grease, and minimize the wear of the bearing.

Secondly, in addition to the impact of the lubrication effect of the raceway on the slewing bearing of the bucket turbine, the upper body of the bucket turbine has a deviation in the balance moment, which makes the bearing wear in the raceway more serious. Therefore, during maintenance, pay attention to the upper part of the body. Heavy correction to reduce the deviation of the balance moment of the upper body of the bucket turbine.

Finally, pay attention to the installation of local tempering belts on the inner and outer rings of the bearing. Resolutely do not install the tempering belts on the inner and outer rings. They must be installed staggered from each other to reduce the bearing capacity of the bearing and reduce the wear of the tempering belt during the operation of the bearing. .