The excavator can rotate left and right during operation, which is inseparable from the slewing device, and the slewing ring is an important part of the slewing device, which is used to support the work ticket load and body quality of the upper body. However, when the working environment is bad and the slewing bearing operates under heavy load, the slewing bearing is prone to failure and various abnormal noises. Let's look at the case study!
Fault details:
During the construction of a Caterpillar 336d excavator not long ago, it was found that the rotary excavator always made abnormal noise
Failure cause analysis:
1 check that other actions work normally, but the engine can not run at high speed when the working device works, only at idle speed
2. The fault point is locked in the rotary motor. When rotating, the SH pipeline of the time delay valve is removed and no pressure oil is found when rotating
3 check the hydraulic diagram and find that the SH oil circuit of the vehicle is not provided by the shuttle valve, but by the main control valve after the internal working idle oil circuit is cut off. The reason why there is no pressure oil in the oil circuit is locked in the orifice
4 after disassembling and inspecting the orifice, it was found that the filter screen of the orifice had been completely blocked
Troubleshooting of abnormal sound when Caterpillar excavator does not rotate during rotation:
Heat the orifice filter screen with oxygen, burn and clean the impurities inside, and return to normal after installation
Fault analysis:
There are four situations in which the excavator makes noise when rotating
(1) There is a noise in the rotary reducer If the noise is from the rotary reducer, first check whether the reducer pin has fallen out If the pin falls out, it can be repaired If the pin does not fall out, the planetary gear or bearing of the rotary reducer may be damaged If the planetary gear or bearing is damaged, replace the damaged part and remove the debris of the damaged part; After cleaning, add new reducer oil before continuing to use
(2) There is a noise in the rotary disc If it is found that the sound is from the inside of the rolling plate, the steel ball or spacer is generally damaged, otherwise the rolling path is crushed For this, disassemble the roller disc for inspection, repair or replace the roller disc
(3) If the noise is caused by the meshing teeth between the rotary reducer and the rotary roller, it may be caused by the following reasons:
① The rotary reducer gear or the roller gear is damaged If a few teeth fall out, they can be repaired for use: if the teeth are seriously rotten, they should be replaced with new parts
② Excessive meshing clearance makes noise; The meshing clearance should be adjusted
③ The gear of the reducer is not concentric with the gear of the rotary roller disc, which makes a noise during the meshing process; Its coaxiality shall be adjusted
④ The noise is caused by excessive meshing clearance between the rotary motor and the spline teeth of the rotary reducer: the meshing teeth should be repaired or replaced.
