Liability determination after serious damage to oil pump

After the oil pump is damaged, you must first check the appearance, interior and related phenomena of the oil pump. When the following phenomena occur, you can determine the corresponding reasons by summarizing them:

1. Bearing damage: When the oil pump is seriously damaged, as long as the bearing is confirmed to be damaged, it can be regarded as caused by improper installation, because the bearing is damaged first after being stressed, and the parts are damaged later. Once the bearing is damaged, the shaft will swing at high speed. Swinging may cause damage to other parts;

If the bearing of the new pump is damaged first, but the other parts are still intact, this is caused by misalignment or hard knocking when installing the oil pump. When a double-acting vane pump works normally, the pump exerts no force on the shaft, and the bearings hardly wear. Generally, they can be used for 10-15 years without breaking down. The only difference between the bearings and ordinary bearings is the noise, and the difference in life is relatively small.

2. There is rust in the inner tank: When the oil pump is seriously damaged, there will only be rust in the pump. It can always be regarded as caused by water entering the oil, because when the oil is normal, rust will never occur.

3. Poor oil quality: When the oil pump is seriously damaged, as long as there are dirt, debris and foreign matter in the oil pump body or the pump core turns black, it can be considered to be caused by poor oil quality.

4. The mandrel is broken: Try to check the fracture location. If the material or heat treatment is not good, the damage point should be the weakest link, that is, the smallest diameter or the spline. If it does not break at the weakest point, it should be regarded as installed. Improper, coaxiality deviation is too large, sometimes the pump core is worn and the resistance increases or the pressure is too high, the shaft will break. Shaft breakage is actually a kind of mechanical protection.

5. The stator has edges: caused by poor oil absorption.

6. Material inspection of damaged parts: The material composition, metallographic structure, hardness, etc. should be inspected. At the same time, the sequence and causal relationship of the damaged parts should be analyzed, and the cause can eventually be found.

The five major killers in the use of vane pumps mentioned above are universal to a certain extent. Together with the existence of other improper use factors, among many oil pump failures, the failure rate caused by users' poor methods and lack of technology accounts for a large proportion. A high proportion, and the judgment of the cause of the failure, along with the difference in personal technical quality, has led to quality disputes with the manufacturer. This article has certain guiding significance for quality disputes and reasonable use.