Causes and preventive measures of abnormal vibration of front axle of L180F loader

1. malfunction

When the 1 Volvo L180F loaders are running 8000h, the front part of the loader has abnormal sound, which is carefully detected

Now, the abnormal sound comes from the front axle differential of the loader and the suspected parts of the front axle knocking on the front axle housing. It is presumed that the front axle gear is worn or broken. After opening the oil drain plug of the front axle lubricating oil, it is found that the flowing gear oil contains iron filings.

2. front axle structure

The loader axle transmission route for the front drive shaft, a driving bevel gear, a driven bevel gear, differential, half shaft, a half shaft to transmit power to the wheel reducer, half axis, the sun gear, planetary gear, planetary gear, wheel hub, as shown in figure 1.

3. cause analysis of trouble

All the front axles of the loader were disassembled and found that the teeth of the active bevel gears had pitting corrosion and fatigue wear, and the teeth of the individual gears were peeled off. The analysis shows that the gear of the active bevel gear is damaged and causes vibration and collision during operation, and sounds of the front axle housing are knocked out.

The failure forms of gear drive include 4 kinds of pitting corrosion, adhesion, abrasion and gear fracture. The pitting of the active bevel gear is pitting and the metal is flaking off. The initial failure is pitting. When pitting occurs, fatigue cracks occur on the tooth surface. The crack phenomenon is gradually serious and penetrates the surface hardening layer, and gradually reaches the deep layer, and finally causes the tooth top to peel off.

When the top of the driving bevel gear is peeled off, the meshing clearance of the main and passive bevel gears increases, and the driving surface of the driving gear is unstable and has an impact. On the one hand, the impact causes abnormal sound; on the other hand, it increases the alternating contact stress caused by the meshing of adjacent teeth, and accelerates the wear of adjacent teeth.

The main reasons for tooth surface wear are the following 5 points:

First, the quality of gear processing is poor, two is unreasonable gear assembly gap, three is overload when loader operation, four is improper operation, and five is maintenance is not in time.

The analysis shows that the quality of gear machining is poor, which is characterized by insufficient gear hardness, poor accuracy and poor finish. The gap between the gears is unreasonable, mainly because of too large or too small assembly gap. When these 2 problems arise, usually in the early use of loaders, the front axle will appear heating, noise increases, and gear wear and so on. The loader has used 8000h, so it belongs to this kind of reason.

4. preventive measures

The loading quality of the Volvo loader is 9t, such as long overload operation, which will cause the main and passive bevel gear load of the front axle to be too large, which will lead to wear of the main and passive bevel gears due to oil film damage. If the driver in the driving process, frequently in the forward and backward blocking switch between, even loader in advance not to be stopped or replace the back gear, will cause a great impact on the main axle, a driven bevel gear, which leads to tooth wear. If the maintenance of the loader is not in place, the lubrication oil will be lost or the quality will be reduced, and the front axle gear will be accelerated to wear.

Our company has many L180F and L220E type Volvo loaders. In order to prolong the service life of these loaders, we have adopted the following 4 measures:

First, strictly control the operation intensity of loaders, and strictly forbid overloading.

Two, according to the loader use time to its front, back, bridge and other important parts of the demolition and inspection, and found that hidden trouble in time out.

Three, regular replacement of the front and rear axle gear oil, often check the main and passive bevel gear whether abnormal sound, to judge the main and passive bevel gear gap.

Four is the main drive axle oil drain plug to plug with magnetism, to absorb iron debris, preventing the metal debris into the oil, causing accelerated wear of tooth surface.

By adopting the above measures, the fault of the front and rear axles of the model loader is obviously reduced, the gear damage is not happened again, and a large amount of maintenance funds is saved for the company, and the economic benefits are indirectly created.