Issues Related to Smooth Grinding of Crankshafts of Natural Gas Generator Sets

The smooth grinding process of the crankshaft of the natural gas generator set is one of the key processes to ensure the quality of the repair. When the outer surface of the timing gear journal and the flange of the flywheel is used as the reference for smooth grinding and paste, the curvature must be corrected before grinding. The swing difference of the middle main journal before grinding must not be greater than o. 3 mm. If the bending is not corrected in advance, after weaving, the crankshaft will generate a new axis that intersects the original flywheel flange and the timing gear axis, changing the radius of gyration, destroying the dynamic balance force, shortening the service life, and increasing the wear of related parts. The noise of the hour gear is also loud, and the rear oil seal leaks, which increases the unbalanced rotating mass of the engine.

Strictly ensuring that the size of the crankshaft journal fillet radius of the natural gas generator set meets the requirements of the drawing is one of the key issues in the quality of repair. However, the general auto repair shop does not pay enough attention to this. The grinding wheel is rarely ground, and the fillet radius of the smooth grinding is often less than the specified size. According to statistics, the fillet radius is less than 2.5 mm, and its fatigue strength is only less than 80% of the fillet radius of 2.5 mm. Since the grinding wheel for grinding the crankshaft is often trimmed with the grinding wheel fillet corrector attached to the grinder to make the ground fillet size meet the requirements, there has been no broken shaft since the vibration surfacing was put into production.

During the operation of natural gas generator sets, due to the complex forces and working conditions of the crankshaft, the sliding speed of each friction surface is very high, and the heat dissipation conditions are poor. Therefore, the main journal and connecting rod journal of the crankshaft will inevitably be worn during operation. Moreover, the wear is uneven, which is mainly manifested by the roundness of the journal, the cylindricity exceeding the standard value and the strain. The most worn part of the connecting rod journal is generally on the inner side of each journal, that is, on the side of the crankshaft centerline, so that the journal is out of round; and the part that wears into a cone is generally on the side where impurities adhere to the lubricating oil passage. On the side and the place where the force is large. The wear parts of the crankshaft main journal _ vary according to the degree of strengthening of the engine, the number of cylinders, the length of the crankshaft and the counterweight of the balance weight, and the wear of the journal should be more even than that of the connecting rod journal. Practice has shown that the wear of the connecting rod journal is faster than the wear of the main journal, but the main journal wear is more serious than the wear of the connecting rod journal.

Inspection and treatment methods for natural gas generator sets. According to the law of wear of each journal, the worn part can be found out, and the roundness and cylindricity can be measured with the outside diameter micrometer in order to determine the repair level and grinding size of the crankshaft.

The smooth grinding process of the crankshaft is one of the key processes to ensure the quality of the repair. When the outer surface of the timing gear journal and the flange of the flywheel is used as the reference for smooth grinding and paste, the curvature must be corrected before grinding. The swing difference of the middle main journal before grinding must not be greater than o. 3 mm. If the bending is not corrected in advance, after weaving, the crankshaft will generate a new axis that intersects the original flywheel flange and the timing gear axis, changing the radius of gyration, destroying the dynamic balance force, shortening the service life, and increasing the wear of related parts. The noise of the hour gear is also loud, and the rear oil seal leaks, which increases the unbalanced rotating mass of the engine.

Strictly ensuring that the size of the crankshaft journal fillet radius meets the requirements of the drawings is one of the key issues in repair quality. However, the general auto repair shop does not pay enough attention to this. The grinding wheel is rarely ground, and the fillet radius of the smooth grinding is often less than the specified size. According to statistics, the fillet radius is less than 2.5 mm, and its fatigue strength is only less than 80% of the fillet radius of 2.5 mm. Since the grinding wheel for grinding the crankshaft is often trimmed with the grinding wheel fillet corrector attached to the grinder to make the ground fillet size meet the requirements, there has been no broken shaft since the vibration surfacing was put into production.

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Post time: Sep-30-2021