Fault Analysis And Application Research Of LW900K Loader Exhaust Gas Turbocharger

At present,the loaders in Chinese construction machinery are applied to various fields of national production,and gradually develop toward high power,high efficiency and large tonnage.In order to adapt to the market demand,Xugong Group has developed and designed the new LW900 K wheel loader through extensive market research and absorption of imported advanced design and manufacturing technology.According to the production needs,Yunnan Phosphate Group Co.,Ltd.purchased 10 sets of LW900 K new wheel loaders from Xugong Group,which were put into use in the four major mining areas of the Group,and two sets of Jianshan Phosphate Mine Branch,which are mainly responsible for product loading.The commissioning of two new loaders has greatly improved the loading capacity of the product mines and effectively solved the production bottleneck.Later,one of the loader engine turbochargers was broken and the new supercharger was replaced.However,since then,the engine loaders of the two loaders have been damaged,which has seriously affected the handling of ore and increased operating costs.By using software analysis,combined with the installation structure of QSM11 engine on LW900 K loader,the emphasis is placed on the analysis and search of engine supercharger oil lubrication.After the fault source is preliminarily determined,the stop test is further done for the fault source.It is proved that one of the main reasons for the burnout of the turbocharger is short of oil,and the turbocharger has a very high working speed,the wear of the rotating shaft and floating bearing is aggravated,and the rotating inertia of the rotor group is too large to stop in time.The shaft is twisted under rotating torque,which leads to the failure of the turbocharger.The second reason is that the filter hole of the crankcase absorber is blocked and there is no work of breathingUse,will cause engine crankcase to produce high temperature,high pressure.The high pressure exhaust produced by the crankcase can not be discharged in time.It enters the turbocharger shaft in the reverse direction from the oil return pipe of the supercharger.Because of the gas disturbance,foam oil is produced in the oil channel of the turbocharger rotor group.The lubricating oil can not establish effective lubricating oil film on the rotor shaft surface.Due to the high rotational speed of the supercharger,the large moment of inertia of the rotor shaft and the serious wear of the shaft diameter of the rotor shaft,the axial diameter of the turbocharger is broken under the action of the shearing torque caused by the rotating torque and vibration,thus leading to the early invalidation of the whole turbocharger.In view of the fault reasons,the installation position of QSM11 engine oil filter on LW900 K loader was redesigned,the built-in respirator was changed into the external breathing apparatus,the corresponding materials were purchased,and the installation was carried out.