Causes of Abnormal Sound in Operation of Shangchai Generating Unit

After the diesel generator set started, the upper part of the body that heard the first and second cylinders has a very sharp, high-pitched metal knocking sound; when the diesel engine speed suddenly drops from high speed to low speed, it can hear a kind of “when, when.” The metal knocks, what's going on here? This kind of failure is generally caused by the excessively advanced fuel supply angle of the diesel generator set or excessive wear of the connecting rod bushing. The specific content of the full power to make an introduction.

First, after the diesel generator sets start, the abnormal sound of the body causes:

1. The clearance between the piston pin and the small copper bushing of the connecting rod is too large.

2, the piston pin and pin seat hole too loose.
 

Second, troubleshooting methods:

1. Take off the side covers of the first and second cylinders and transfer the diesel flywheel so that the pistons of the first and second cylinders are respectively at the bottom dead center of the compression stroke.

2. Hold the middle position of the connecting rod by hand and shake it back and forth to observe whether the piston pin has a swaying feeling. As a result, it is found that the second cylinder piston pin has a swaying feeling and there is a metal collision sound.

3. Disassemble the cylinder head and take out the piston rod assembly. It is found that the copper bushing of the connecting rod is seriously worn and causes abnormal noise.

4. After replacing the connecting rod bushings, assemble the piston connecting rod assembly and cylinder head according to the assembly requirements and sequence, and then adjust the valve clearance.

5. After the preparatory work of the diesel generator is completed, the diesel engine is started to check and it is found that the metal knocking sound disappears, the diesel engine runs smoothly, and the fault is eliminated.

The above is the cause of abnormal noise and the troubleshooting method for the generator unit after the start of the Shangchai generator set. It is hoped that the above introduction can bring users reference.