Many users did not know enough about the installation of the slewing ring, often resulting in improper operation of the slewing ring due to installation errors or inaccuracies, such as inflexible rotation, abnormal sound, etc., today led by Xuzhou Jieheng Slewing Bearing Co., Ltd. Xiaobian Learn how to install slewing rings and slewing bearings so that everyone can reduce problems and mistakes in installing slewing rings.
First, before installing the slewing ring, it is necessary to inspect the mounting surface of the main machine. It is required that the supporting member should have sufficient strength, the connecting surface should be machined, and the surface should be smooth and free of debris and burrs. For those that cannot be machined to achieve the required flatness, special plastics with high injection strength can be used as fillers to ensure the accuracy of the mounting plane and to reduce vibration. The slewing ring of the slewing bearing has a hardened soft zone, which is marked with S on the end face of the ferrule. When installing, the flexible tape should be placed in the non-load zone or in the non-recurrent zone (the plug hole is always located in the soft zone. ).
Second, when installing a slewing ring, radial positioning should be performed first, cross-tighten the mounting bolts, and check the rotation of the bearing. In order to ensure smooth bearing transmission, the gears should be inspected before the mounting bolts are tightened. When tightening the bolt, there should be enough pre-tightening force, and the pre-tightening force should be 70% of the yield limit of the bolt material. The mounting bolts should be equipped with flat washers. It is forbidden to use spring washers. After the installation of the slewing bearing is completed, it is put into operation. After 100 hours of continuous operation, it is required to fully check whether the pre-tightening torque of the mounting bolt meets the requirements. The above inspection is repeated once every 500 hours of continuous operation.
Third, the slewing ring should be filled with an appropriate amount of grease after installation, and should be filled with side slewing bearings so that the grease is evenly distributed. After a period of working time, the slewing ring bearing will inevitably lose a part of the grease. Therefore, the slewing ring bearing should be replenished once every 50 to 100 hours in normal operation. For slewing bearings that operate in high temperature environments or in dusty conditions, the period for adding lubricating grease should be appropriately shorter. When the machine is to be shut down for storage, it must also be filled with sufficient grease.
4. During the transportation process, bearings should be placed horizontally on the vehicles. Measures should be taken to prevent slipping and prevent vibration. If necessary, add auxiliary supports.
5. Bearings should be placed horizontally on a dry, ventilated, and flat site. Storage should be isolated from chemicals and other corrosive materials. If multiple sets of bearings need to be stacked and stacked, three or more equal-height wooden spacers should be placed uniformly in the circumferential direction between each set, and the upper and lower spacers should be placed in the same position. Bearings that need to continue to be stored beyond the rust-proof period should be cleaned and rust-proofed again.
Six, flat installation, the installation surface should be smooth, to remove all the excess material such as paint residues, beads, burrs and so on. Be careful not to let the solvent penetrate the inside of the slewing ring during cleaning, and do not use solvents that damage the sealing material. The mounting surface should be dry and free of lubricant before assembly. Measures should be taken to protect workers and the environment. The roughness of the mounting surface of the mounting bracket is not greater than Ra=12.5, 6.3μm. The flatness error of the mounting surface must detect the circumferential error and radial error. The circumferential flatness tolerance value has a corresponding standard value range with the diameter of the slewing bearing raceway.
Seven, the slewing bearing inner and outer ring raceways have a soft band, should be placed on both sides of the main load plane. That is, it is offset 90 degrees from the main load area. There is a blockage or “S” mark at the soft band. In addition, check the match between the slewing bearing and the mounting surface. Usually, feeler check is used. If the fit is not good, use appropriate materials to fill. After the slewing bearing is installed, it is forbidden to carry out welding work on the bearing.
Eight, strong bolt
(1) Selection of mounting bolts: Use the specified mounting bolts and washers. Also note: Do not use full-threaded bolts. Do not use old bolts, nuts, and washers. Do not use open washers such as spring washers.
(2) Selection of bolt pre-tightening torque: The pre-tightening force of ordinary metric bolts is recommended to be 0.6-0.7 times the bolt yield strength. It is recommended to use hydraulic fastening devices for bolts larger than M27. The preload should not exceed 85% of the yield strength.
(3) Fastening bolts: The slewing ring should be installed under no load conditions. Note: Apply a bit of oil on the thread of the bolt to ensure a uniform balance of friction. Do not use glue on the bolt loose parts. Pre-tightening bolts: It should be pre-tightened in three steps. The three-step forces are 30%, 80% and 100% respectively.
Nine, adjust the backlash of the gear, when installing the slewing bearing of the tooth, it is very important to adjust the backlash of the gear correctly. The feeler can be adjusted with a feeler gauge at the highest point of the radial runout of the gear, or it can be made of pressed wire or other suitable method. If the backlash is not within the specified value, the movable pinion changes the center distance. After setting, turn the slewing ring at least one full revolution to confirm that there is no other tooth high point. Check the backlash clearance after the slewing ring is finally fixed. The highest point of the radial runout of the gear is marked with green paint in the tooth gap.
Ten, first lubrication
(1) Raceway lubrication: In order to ensure adequate lubrication, grease should be re-primed on the drawings or product instructions before initial use. Pay special attention to all the grease nipples one by one. It is best to turn the grease while rotating the slewing ring until you see the grease squeeze out of the seal.
(2) Gear lubrication: When the gear is lubricated, the tooth surface should be clean. It is recommended to use a clean brush to brush the grease on the gear.
The above are some issues that need special attention in the installation process of the slewing ring. I hope it can be useful to you. For more information about slewing bearings, please pay attention to Xuzhou Jieheng Slewing Ring Information Center, or call us directly at 0516-83310721.