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大多数的现代发动机具有悬挂曲轴、铸焊结构的机体—曲轴箱。这种机体制造工艺性好,并保证发动机的金属消耗量低。但是这种结构在主轴承支座窗孔处,尤其在窗孔轮廓到主轴承螺母支承面的过渡圆弧处存在着很高的拉应力,它是由悬挂曲轴主轴承螺栓的预紧力产生的。在这些部位还有很大的缸内燃气压力产生的交变拉应力。支座窗孔的过渡圆弧处存在很高的静态拉应力,是因为该处抵抗塑性变形的能力低,结果使曲轴支承圆角处的变形增大,而在交变载荷的作用下这导致疲劳裂纹的出现。为此,在具有铸焊机体的ⅡДP49(6ЧH26/26)新型直列式柴油机上,对不同外形的主轴承支座和不同的
Most modern engines have crankshafts, cast-welded structures - the crankcase. This body is made of good workmanship and guaranteed low engine metal consumption. However, this structure has a very high tensile stress at the bearing hole of the main bearing, especially at the transition arc of the profile of the window hole to the bearing surface of the main bearing nut, which is generated by the preload of the main bearing bolt of the suspension crankshaft of. There is also a great amount of alternating tensile stress in these locations caused by gas pressure in the cylinder. There is a high static tensile stress at the transitional arc of the bearing window because of its low ability to resist plastic deformation, with the result that the deformation of the crankshaft bearing fillet increases, which results under alternating loads Fatigue cracks appear. To this end, cast iron body with Ⅱ D P49 (6ЧH26 / 26) new inline diesel engine, different shapes of the main bearing support and different