Crankshaft cracks of diesel generator sets mostly occur at the end of the connecting rod journal or the junction of the crankshaft arm and the shaft journal. The inspection methods include magnetic flaw detection method, hammer method, powder stain method, lime milk method, etc.
Inspection method one for crankshaft cracks and fractures of diesel generator sets: magnetic flaw detection method
Use a magnetic flaw detector for inspection. First, magnetize the crankshaft of the generator set with a magnetic flaw detector, and then sprinkle iron powder on the part that needs to be inspected, while gently tapping the crankshaft with a small hand hammer. At this time, pay attention to observation, if there are cracks, there will be clear crack lines in the middle of the accumulation of iron powder.
Inspection method two for crankshaft cracks and fractures of diesel generator sets: hammering method
First remove the oil stains adhered to the surface of the crankshaft of the diesel generator set, then soak the entire crankshaft with kerosene or diesel, take it out and wipe it clean, and then support the two ends of the crankshaft on the wooden frame, and tap each side with a small hammer. Crank arm. If it emits “锵,锵” (coherent sharp metal sound), it means that there is no crack; if it emits “wave, wave” (incoherent, short dumb metal sound), it means that there is a crack. Then, use your eyes or use a magnifying glass to observe the areas that are prone to cracks nearby. If you find oil stains or a black line, the cracks are located.
Inspection method three for crankshaft cracks and fractures of diesel generator sets: powder stain method
Wash the crankshaft of the diesel generator set with kerosene or diesel oil, and then apply a layer of talcum powder evenly on the surface of the crankshaft. Then tap the crankshaft arm with a small hand hammer. If the crankshaft has cracks, oil stains will leak out from the cracks and generate electricity. The talc on the surface of the crankshaft turned yellowish brown.
Inspection method four for crankshaft cracks and fractures of diesel generator sets: lime milk method
Wash the crankshaft of the diesel generator set and soak it in hot oil (oil) for about 2h, let the oil enter the cracks, take it out and wipe dry, spray the “lime emulsion” onto the crankshaft with a spray gun to dry it [lime emulsion is clean chalk and The ratio of the mixture of alcohol is (1:10)~(1:12)]. Or use a gas welding flame to heat the spray layer on the crankshaft to 70-80°C. At this time, the chalk absorbs the oil stored in the crack, and this part of the chalk becomes dark, showing the shape of the crack.
Post time: Jul-13-2021