The excavator can rotate left and right during operation without the slewing device, and the slewing bearing 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 relatively poor, and the slewing bearing is under heavy load operation, the slewing bearing is prone to failure and various abnormal noises. Let's take a look at the case study!
Failure details:
A Caterpillar 336D excavator recently discovered that there was always abnormal noise when the excavator was rotating
Failure analysis:
1 Check that other actions are working properly, but the engine cannot work at high speed when the working device is working, only idling.
2 The fault point is locked in the rotary motor part.When the SH line of the delay valve is removed during the rotation to perform the rotation action, it is found that no pressure oil comes out.
3 Looking at the hydraulic diagram, it is found that the SH oil circuit of the car is not provided by the shuttle valve, but is provided by the internal idling oil circuit of the main control valve after being cut off. .
4 After dismantling the orifice, it was found that the orifice filter was completely blocked.
Carter excavator can not rotate when there is abnormal noise troubleshooting:
Heat the orifice filter with oxygen, burn the impurities inside and clean it, and return to normal after installation.
Failure analysis:
There are sounds when the excavator rotates and it is divided into the following four cases
(1) There is a noise in the rotary reducer. If it is a noise from the rotary reducer, first check whether the pin of the reducer has fallen out. If the pin falls out, it can be repaired. If it does not fall out, then The planetary gear or bearing of the rotary reducer may be damaged. If the planetary gear or bearing is damaged, the damaged parts should be replaced and the fragments of the damaged parts should be removed; after cleaning, add new reducer oil to continue using.
(2) There is a noise in the rotating roller. If it is found that the noise is from the roller, usually the steel ball or the separator is damaged, otherwise the raceway is crushed. For this, the roller should be disassembled to check, repair or replace the roller .
(3) The sound is caused by the meshing teeth of the rotary reducer and the rotary roller, which may be caused by the following reasons:
①The gears of the rotary reducer or the teeth of the rolling disc are damaged. If it is a small number of lost teeth, it can be repaired and used: if the rotten teeth are serious, new parts should be replaced
② The meshing gap is too large to make a noise; the meshing gap should be adjusted.
③The gear teeth of the reducer are not concentric with the teeth of the rotating roller, and they make a noise during the meshing process; the coaxiality should be adjusted
④ The noise is caused by the spline tooth meshing gap between the rotary motor and the rotary reducer is too large: the tooth should be repaired or replaced.
