Analysis Of Performance Fuel Pump Leakage Problems And Measures To Solve Them

Analysis Of Performance Fuel Pump Leakage Problems And Measures To Solve Them

0The main function of the performance fuel pump, also known as the low-pressure fuel transfer pump, is to provide sufficient pressure and relatively constant fuel to the high-pressure pump at a given pressure and delivery volume under various working conditions of the diesel engine. It is a key component of the fuel supply system and its performance has a direct impact on the starting performance and power of the diesel engine. In this paper, we will take the performance fuel pump leakage fault of a certain model as an example to analyze.

1 performance fuel pump structure form and working principle

2 Failure conditions

2.1 Description of fault phenomena

2.2 Inspection of faulty parts

3 Failure cause analysis

According to the fault phenomenon analysis, the cause of the performance fuel pump leakage was the wear of the oil seal by metal debris generated by the active gear bore. The direct cause of the gear churning is the tilt of the main gear shaft, which is not perpendicular to the bottom surface of the gear cavity, causing the gear to rotate abnormally in the gear cavity, resulting in yawing. Possible reasons for the tilt of the active gear shaft: one is the performance fuel pump. There is a problem with the performance fuel pump itself; two is connected with the performance fuel pump transmission mechanism there are problems. Based on this a performance fuel pump leakage fault tree is established.

3.1 Problems with the performance fuel pump itself

3.1.1 Skeleton oil seal problems

3.1.2 Pump body problems

3.1.3 Pump cover problems

3.1.4 Problems with the perpendicularity of the active gear end face to the active shaft

3.1.5 Cleanliness issues

3.2 performance fuel pump drive train problems

3.2.1 Design issues

3.2.2 Assembly problems

3.2.3 Quality issues of the components concerned

4 Trial validation

5 Solutions

5.1 Inspection and acceptance control

Strictly control the shape and position tolerances of the shell ① 0.05 back and the middle 0.0641 to prevent the aggravation of the tilt of the active gear shaft during the long-term operation of the performance fuel pump, which will lead to hidden quality problems.

5.2 Processing control

When machining the sleeve part of the gear cavity of the pump body, ensure the critical dimensions such as perpendicularity and roughness of the end face and the sleeve to avoid offsetting of the gear during installation, which can lead to deflection failure.

5.3 Assembly control

Avoid the phenomenon of strain and stagnation of each part in the assembly, and make corrections and adjustments in time to eliminate any consequences.

5.4 Cleanliness control.

Ensure the parts are clean and free of burrs, and ensure the cleanliness of each part in the process of assembling the performance fuel pump to prevent foreign objects from entering the pump body and causing grinding between the bushings of the gear cavity and the shaft. By taking the above improvement measures, the performance fuel pump oil leakage problem can be completely solved.

This article is quoted from Hebei Huabei Diesel Engine Co.