The smooth grinding of the crankshaft of gas-fired generator set is one of the key processes to ensure the repair quality. When taking the cylindrical surface of timing gear journal and flywheel flange as the reference for smooth grinding and paste loading, the curvature must be corrected before grinding. The runout of the middle main journal before grinding shall not be greater than o.3mm. If the bending is not corrected in advance, after weaving and cutting, the crankshaft will produce a new axis intersecting with the original flywheel flange and the axis of the timing gear, which changes the turning radius, destroys the dynamic balance force, shortens the service life, intensifies the wear of relevant parts, the noise of the timing gear is also large, and the rear oil seal leaks, increasing the unbalanced rotation quality of the engine.

严格保证天然气发电机组曲轴轴颈圆角半径的尺寸符合图纸要求，是修复质量的关键性问题之一。但一般汽车修理厂对此并没有足够的重视，砂轮很少修磨，光磨的圆角半径常小于规定的尺寸。有资料统计，圆角半径小于2，5毫米，其疲劳强度只及圆角半径为2．5毫米的80％以下。由于对光磨曲轴的砂轮，经常用磨床附属的砂轮圆角校正器修整，使磨得圆角尺寸符合要求，所以自振动堆焊投产以来，没有发生过断轴现象。

Strictly ensuring that the dimension of the fillet radius of the crankshaft journal of the natural gas generator set meets the requirements of the drawing is one of the key problems in the repair quality. However, the general automobile repair shop does not pay enough attention to this. The grinding wheel is rarely polished, and the fillet radius of smooth grinding is often less than the specified size. According to statistics, if the fillet radius is less than 2 or 5mm, its fatigue strength is only less than 80% of that of 2.5mm. Since the grinding wheel for smooth grinding of crankshaft is often trimmed with the grinding wheel fillet corrector attached to the grinder to make the grinding fillet size meet the requirements, there has been no shaft fracture since the vibration surfacing was put into operation.

天然气发电机组在工作中，曲轴由于受力和工作条件复杂，各摩擦表面滑动速度很高，散热条件又差，因此，曲轴的主轴颈和连杆轴颈在工作中不可避免地要产生磨损，而且磨损是不均匀的，其主要表现为轴颈出现圆度，圆柱度超过标准值和拉伤。连杆轴颈磨损的部位，一般在各轴颈的内侧面上，即靠曲轴线一侧，使轴颈失圆；而磨损成锥形的部位，一般在润滑油道杂质附着的一侧和受力大的部位上。曲轴主轴颈_的磨损部位，按发动机的强化程度、气缸数、曲轴长度和平衡块的配重不同而各异,而且相对于连杆轴颈磨损要均匀些。实践表明,连杆轴颈的磨损比主轴颈磨损要快，但是，主轴颈磨损比连杆轴颈磨损所造成的后果要严重。

In the operation of natural gas generator set, due to the complex stress 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 in the operation, and the wear is uneven, which is mainly manifested in the roundness of the journal, the cylindricity exceeding the standard value and strain. The most worn part of the connecting rod journal is generally on the inner side of each journal, that is, the side close to the centerline of the crankshaft, which makes the journal out of round; The parts worn into a cone are generally on the side where impurities in the lubricating oil passage adhere and on the parts with large stress. Crankshaft main journal_ The wear parts vary according to the strengthening degree of the engine, the number of cylinders, the length of the crankshaft and the counterweight of the balance weight, and the wear is more uniform relative to the connecting rod journal. Practice shows that the wear of connecting rod journal is faster than that of main journal, but the consequence of main journal wear is more serious than that of connecting rod journal.

天然气发电机组检验与处理方法。根据各轴颈磨损规律查找出磨损部位,可用外径测微器测量其圆度和圆柱度以便确定曲轴的修理级别和磨削尺寸。

Inspection and treatment methods of natural gas generator set. Find out the worn parts according to the wear law of each journal, and use the outer diameter micrometer to measure its roundness and cylindricity, so as to determine the repair level and grinding size of the crankshaft.

曲轴的光磨加工情况，是保证修复质量的关键工序之一。以正时齿轮轴颈和飞轮突缘的外圆表面作为光磨装-膏基准时，必须先校正弯曲度再进行磨削，磨前中间主轴颈的摆差不得大于o．3毫米。如果不预先校正弯曲，织削以后将会使曲轴产生与原来飞轮突缘和正时齿轮轴线交叉的新轴线，改变了回转半径，破坏了动平衡力，缩短使用寿命，加剧有关零件的磨耗，正时齿轮的响声也大，后油封漏汕，增加了发动机的不平衡旋转质量。

The smooth grinding of crankshaft is one of the key processes to ensure the repair quality. When taking the cylindrical surface of timing gear journal and flywheel flange as the reference for smooth grinding and paste loading, the curvature must be corrected before grinding. The runout of the middle main journal before grinding shall not be greater than o.3mm. If the bending is not corrected in advance, after weaving and cutting, the crankshaft will produce a new axis intersecting with the original flywheel flange and the axis of the timing gear, which changes the turning radius, destroys the dynamic balance force, shortens the service life, intensifies the wear of relevant parts, the noise of the timing gear is also large, and the rear oil seal leaks, increasing the unbalanced rotation quality of the engine.

严格保证曲轴轴颈圆角半径的尺寸符合图纸要求，是修复质量的关键性问题之一。但一般汽车修理厂对此并没有足够的重视，砂轮很少修磨，光磨的圆角半径常小于规定的尺寸。有资料统计，圆角半径小于2，5毫米，其疲劳强度只及圆角半径为2．5毫米的80％以下。由于对光磨曲轴的砂轮，经常用磨床附属的砂轮圆角校正器修整，使磨得圆角尺寸符合要求，所以自振动堆焊投产以来，没有发生过断轴现象。

Strictly ensuring that the dimension of the fillet radius of the crankshaft journal meets the requirements of the drawing is one of the key problems in the repair quality. However, the general automobile repair shop does not pay enough attention to this. The grinding wheel is rarely polished, and the fillet radius of smooth grinding is often less than the specified size. According to statistics, if the fillet radius is less than 2 or 5mm, its fatigue strength is only less than 80% of that of 2.5mm. Since the grinding wheel for smooth grinding of crankshaft is often trimmed with the grinding wheel fillet corrector attached to the grinder to make the grinding fillet size meet the requirements, there has been no shaft fracture since the vibration surfacing was put into operation.