Thursday, December 20, 2012

Hardware knowledge: cutting the crankshaft causes and countermeasures -hardware, crankshaft, bearings

Crankshaft caused by cutting and countermeasures: crankshaft erosion, especially by the crank pin and bearing oil film between the failure to develop an effective, so that the crank journal and bearing a direct result of the conflict. Erosion occurs when crankshaft, they run the white smoke that offers various metal boom and even the crankshaft and the bearing will not lead to turn the lock. It should therefore be the cause of their not correctly analyze and assess.
/> 1, poor quality oil: 1) poor quality oil. Using oil quality and viscosity grade level or lower varieties are mixed with the oil, allowing power consumption below the usual oil, oil mixing process using a lot of dust and diesel engine operating temperature is too high because oil oxidation metamorphosis. Oxidative degradation of the oil black, dull, higher concentration, using two fingers, rotate the oil, may feel dust and other contaminants. If he is found on the current situation with oil, it must change with time. 2) dilution of the oil. As part of the diesel engine fuel injection pump lubrication with forced lubrication, and Oil Road once. The fuel oil pump seal failures chamber diesel oil is diluted, deterioration of engine oil. Seeps more than the broken set or trachoma flow holes in the cooling water in oil oil is more slender. The top diesel can (cylinder head level, valve body, the cylinder head housing), whether steam or droplets. If, in order to increase the use of oil, decreased concentration, reducing viscosity, and the oily residue oil is represented in the mixed fuel. Import the valve door />
2, not enough oil reserves, oil is lower pressure: pioneer insufficient oil stocks, oil pressure, insufficient flow of the diesel engine lubricating oil, and then can not be guaranteed crankshaft journal and bearing lubricant between the films. The amount of oil in the oil pan and oil pressure gauge reading and check out additional checks whether the blockage of oil pipelines, exits and other anomalies.
/> 3, crankshaft journal and the bearing clearance too large or too small: 1) crankpin and has its own too much space, which can lead to low oil pressure, does not constitute sufficient film oil. 2), the crankshaft bearing journals and is very small, because the gap between the crank pin and thickness of oil film bearing is inadequate or movie. If the gap is too big or too time available micron check table quantities cylinder bore journal bearing, bearing size, where the distance is calculated, can also be measured directly using a feeler gauge distance.
/> 4, crankshaft and cylinder geometry of super-diversity: 1) the larger crankshaft concentricity tolerance, so that the journal and the bearing clearance is less or no gap, lack of lubrication or no lubrication film. 2) The cylinder block main bearing bore concentricity tolerance, which is in the neck and shaft bearing gap is too small or no gap, insufficient lubrication or no lubrication film. 3) The cylinder and main bearing bore perpendicularity what crankpin spindle collar gap is too small or no gap, insufficient lubrication or no lubrication film. Overhauled used in new machines or diesel engines will not be long in the case and often generate the phenomenon. Determine the geometry of the part tolerance firsthand shake to switch to diesel crankshaft (not effort), and then connecting rod of pine-cylinder diesel engine main bearing caps and unloading of the cap, then turn the crankshaft. Change depending on the size of the torque of the rotating crankshaft, to indicate different (but the difference in size too, need the disintegration of diesel engines to submit to specific content).