The abnormal wear of the bush is due to these causes!

So, what role does a bush play in the engine components? How can abnormal wear and burned bush damage an engine?

The back pad of the bearing bush is usually made of steel or bronze and coated with a friction alloy layer. When a high horsepower and high torque engine is in operation, the shaft tile and crankshaft will form a relative high speed sliding between them and bear a huge shock load, and need to rely on the oil film produced by the crankshaft and crankshaft bush gap to lubricate and support them, and transfer the heat generated by the friction to make their engines work properly.

In simple terms, between the shaft and the crankshaft need to have a very thin film of oil to play a lubricating role, and this film is actually the oil lubrication effect, so as to prevent the engine crankshaft, piston and other parts of the hard friction. You should know that this liquid lubrication friction is the most ideal working condition for the shaft, both to cool the shaft, but also to avoid direct contact between the shaft bush and the shaft to produce dry friction.

 

Despite the design and production efforts to achieve good lubrication of the bearings, however, in the actual operation of the engine, may be affected by driving habits, speed, working conditions and oil quality and other changing factors, the shaft bush can not always operate under ideal working conditions, often in a semi-liquid, semi-dry friction state, always do not have sufficient lubrication, so in the absence of oil, the shaft bush wear will be unusually serious.

Especially for high horsepower and high torque engines, once the mechanical and thermal loads are too high, the oil supply is insufficient or there are impurities or abnormal viscosity of the lubricant, it will be difficult to form an effective lubricant film between the crankshaft and the shaft bush, thus leading to dry friction between the crankshaft and the shaft bush.

When the wear of the shaft tile exceeds the permissible limit, it should be serviced at a service station. Otherwise, the high temperature generated by abnormal friction may melt the alloy layer on the surface of the shingle, intensifying the dry friction between the bush and the crankshaft, which will cause damage to the bush and.

 

Causes of abnormal wear of shaft bush

Diesel engine lack of oil, lubrication, cooling strength is not enough.

Water or diesel oil mixed with the oil reduces the lubricating properties of the oil.

The oil is not clean, mixed with small particles of impurities.

The temperature of diesel oil is too high, which makes the oil viscosity too low and the oil pressure drops.

Incorrect oil quality selection, oil non-compliance or long term use of engine oil without replacement makes it difficult to form a good lubricating oil film, causing mechanical friction or corrosive wear. It is important to know that the quality of the engine oil will directly affect the normal operation of the internal parts of the engine.

Due to the long-term use of diesel engines, the crankshaft journals have great wear, their roundness and cylindricity exceed the permissible range, and the lubrication performance is reduced.

The engine is in a long-term overload working condition, the lubricating oil temperature is too high, the viscosity drops, the impact load between the shaft bush and the crankshaft increases, causing abnormal wear of the shaft bush.

Before starting the diesel engine, there is no pre-lubrication and there is not enough oil on the lubricating surfaces. Or in the case of oil temperature is too high to stop, bearing clearance can not keep the oil film, after starting again, causing these friction surface dry friction, so that the surface of the crankshaft and bearing bush abnormal wear.

The oil filter used does not meet the requirements, the oil filter is not effective or has high resistance.

Due to oil pump failure, or lubrication line leakage.

Diesel engine oil temperature is too low, on the sudden increase in speed and load, the establishment of the oil film is not uniform, will also cause abnormal wear of the bush.

When the ambient temperature is below 0 degrees Celsius in winter, the engine is started quickly and forcibly into work without sufficient preheating.

 

How to avoid abnormal wear of bearing bush

So how do we try to avoid these situations? First of all, in terms of lubrication, add enough oil to meet the requirements, and regularly clean the oil filter and replace the filter element, while eliminating the hidden danger of diesel engine oil leakage.

Further ensure that the diesel engine main oil passage, crankshaft oil passage and all lubricating oil passages are smooth, and ensure that the lubricating oil is clean and replaced regularly.

When the diesel engine oil and water temperature is low, do not suddenly increase the throttle and raise the speed. When the oil temperature is too high, do not stop immediately (usually need the oil temperature below 60 degrees). In addition, reduce long-term overload conditions and try to keep the oil temperature within the limit, too high oil temperature will reduce the oil viscosity.

 

Keep engine parts clean to prevent carbon, fuel and cooling water from entering the lubrication system. At the same time, use qualified shafts and bearing bush, and regularly overhaul and maintain them, and replace any abnormally worn shafts. In addition, ensure that journals and shafts have the required clearance and adequate oil supply.