Detection Method for Camshaft of Diesel Generator

The camshaft of a diesel generator is subjected to periodic impact loads. The contact stress between the cam and the follower is high, and the relative sliding speed is also high. Camshafts are usually forged from high-quality carbon steel or alloy steel, and can also be cast from alloy cast iron or ductile iron. The journal and cam working surface are polished after heat treatment.

The detection method for diesel generator camshaft is as follows:

1. Check the wear of the camshaft journal. First, clean the camshaft thoroughly, and then measure it directly with an outer diameter micrometer. The measurement points are shown in the figure. If the wear exceeds the specified allowable range, the camshaft should be replaced. The diameter of the camshaft journal is 33.934-33.950mm (according to Iveco diesel generator data).

2. Check the fit clearance between the camshaft journal and the bottom hole.

Measure the inner diameter of the shaft neck bottom hole with an inner diameter micrometer, and then measure the corresponding size of the camshaft neck with an outer diameter micrometer. The difference between the two is the fitting clearance.

The inner diameter of the camshaft journal bottom hole is 33.989-34.014mm, and the fit clearance of the camshaft journal bottom hole is 0.039-0.080mm (data from Iveco diesel engines).

3. Check the curvature of the camshaft axis. Place the camshaft on a V-shaped frame or between the two top pins of the lathe with the two end journals as the support points. Then, use the measuring head of a dial gauge to press against the journal, slowly rotate the camshaft, observe the reading on the gauge, and record the maximum and minimum values of the gauge needle runout. The difference between the two is the curvature, as shown in the figure. If it is greater than 0.04mm, it should be replaced.

4. After the wear of the camshaft journal exceeds the limit, it can be repaired with anchor plating. After repair, it is necessary to ensure the fit clearance between each journal and the bushing.

5. The working surface of the cam should be free from detachment, pits, pitting, or damage. The wear of the cam profile shall not exceed 0.15mm, and if it exceeds this limit, it must be replaced.

6. Check the lift of the cam. The positioning method of the camshaft is the same as above. Place the pointer of the dial gauge against the convex surface of the camshaft for direct measurement. If the measured value exceeds the allowable value, it should be replaced. For example, the intake and exhaust valve cam lift of the 8140.07 diesel engine is 1.05mm, while the intake and exhaust valve cam lift of the 8140.27 diesel engine is 0.9mm.

In addition, there should be no scratches or scratches on the camshaft journal and cam, otherwise the camshaft should be replaced.

Dingbo Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, please feel free to send email to sales@dieselgeneratortech.com we will pay highly attention on your question.