1. Inspection and maintenance items
The main inspection items of slewing mechanism include: whether the lubrication of slewing reducer is normal. Whether slewing bearing, swivel joint and turntable work normally. Whether the torque of bolts and nuts at all parts meet the requirements. The main maintenance items include lubrication of slewing bearing and internal gear and replacement of lubricating oil for slewing reducer.
2. Lubrication of rotary reducer
Interval for changing gear oil: the rotary reducer should be lubricated with corresponding matching gear oil. The first maintenance and oil change cycle of the new machine is 250h, and the later oil change interval is 1000h. Each oil change of 20t excavator needs 3.4L gear oil.
Steps of changing gear oil: first, park the excavator on the flat ground, run the diesel engine at low speed and no load for 5 minutes, and then shut down. Secondly, remove the drain plug at the end of the drain pipe, and install the drain plug again after the old gear oil is drained. Again, remove the oil cap and add gear oil until the oil level is between the marks on the oil dipstick. Finally, replace the filler cap. If the excavator has been working for a period of time, it should wait until the gear oil settles before discharging and replacing.
3. Lubrication of slewing bearing
Lithium grease should be added to slewing bearing and friction surface every 250h. The lubrication steps are as follows: first, park the excavator on the flat ground, lower the bucket to the ground, turn off the automatic idle switch, shut down the engine after 5 minutes of low-speed and no-load operation with diesel engine, if the diesel engine does not run for several minutes at low-speed and no-load, the turbocharger may be damaged. Next, add grease to the slewing ring grease fitting until the grease overflows from the slewing ring seal. The capacity of the grease is about 0.3L. Please do not over fill the grease. Finally, start the diesel engine, lift the bucket off the ground, rotate the upper car for 1 / 8 turn, lower the bucket to the ground, and then add grease to the next slewing bearing filling point. According to the above method, one lubricating point can be filled every 1 / 8 turn of the upper car, and the lubricating grease filling of the rotary mechanism can be completed after 4 times of filling.
4. Rotary gear meshing surface lubrication
The meshing surface of rotary gear should be added with lithium grease every 500h. The preparation for lubrication of the meshing surface of the meshing gear of the slewing mechanism is the same as that of the slewing bearing. The specific steps are as follows: open the upper tool box cover, remove the cover plate of the grease container, add about 0.5kg of grease, and then install the cover plate. Note: there must be grease on the tooth tips of all internal meshing gears of slewing bearing, and there must be no pollution. If the grease has been contaminated, remove the contaminated grease and replace it with clean grease.
