Inspection and Repair of Piston in Diesel Generator Set 1

Starlight Power Generation Equipment has previously analyzed common faults of diesel generator sets for everyone, so what should be done if these faults occur? How to prevent these failures? Today, Starlight Power Generation Equipment has organized the inspection, selection, and repair methods for the pistons of diesel generator sets for everyone, hoping to be helpful.

1. Piston appearance inspection

(1) Visual inspection method. Use the naked eye or a magnifying glass to observe the outer surface of the piston of the diesel generator set for cracks; Whether there are burrs and scratches: The color of the skirt (white is better, other color differences).

(2) Knocking method. Gently tap the piston skirt of the diesel generator set with a hammer to judge the sound. If the sound is hoarse and there is no tail sound, it indicates cracks and should be replaced; If the sound is clear and crisp, it indicates that the piston has no cracks.

2. Measurement of piston skirt

The maximum wear, taper, and out-of-roundness of the piston skirt of a diesel generator set can be measured with an outside micrometer or dial indicator.

It is worth noting that when measuring pistons, the front and rear and left and right values should be measured at the upper, middle, and lower parts of the piston skirt. The difference between the maximum and minimum longitudinal diameters of the diesel generator set pistons is measured as conicity, and the difference between the maximum and minimum cross-sectional diameters is measured as out of roundness. Then, compare them according to the technical requirements of the instructions to see if they can continue to be used.

3. Inspection of radial clearance between piston skirt and cylinder wall. The radial clearance between the piston skirt and cylinder wall of diesel generator sets is clearly specified by each machine. The inspection method is to select a thickness gauge with an appropriate length and thickness that is equal to the measured clearance. The piston is turned upside down and the thickness gauge is placed on the piston skirt. At the same time, the cylinder is installed (at this time, the piston is not equipped with a piston ring, and if used, the old piston and cylinder should be placed in the place with the greatest wear). After being in place, the thickness gauge is pulled out and pulled out by hand, A slight resistance is appropriate.

4. Inspection and adjustment of compression chamber height

(1) The definition of compression chamber height The so-called compression chamber height refers to the distance (gap) between the piston crown and the cylinder head when the piston reaches the top dead center, also known as the compression chamber clearance.

When repairing diesel generator sets, if cylinder liners, connecting rods, connecting rod bearings, piston pin bushings, cylinder pads, and other components have been replaced or repaired, the height of the compression chamber should be checked and adjusted.