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在我厂生产的WY80液压挖掘机中,履带驱动轮与减速器联接的高强度螺栓(图1),松动现象时有发生。究其螺栓强度和制造质量毋庸置疑,原因何在呢?一、松动原因分析1.对螺松进行理化试验。检验结果为:材质为45号钢,硬度HB225～242,抗拉限σ_b=760～820N/mm~2,屈服限σ_s=550～600N/mm~2,没有性能等级标记。而国标GB3098.1-82《紧固件机械性能》规定8.8级螺栓HB240～310,σ_b=800～1000N/mm~2,σ_s=640～660N/mm~2,并强调有性能等级标记。显然,装机使用的高强度螺栓达不到设计要求。2.对螺栓进行强度校核。按减速器的最大输出扭矩和机器原地转弯时土壤对驱动轮产
In the WY80 hydraulic excavator produced by our factory, the high-strength bolts (Figure 1) connected with the track drive wheel and the decelerator loosely occur from time to time. There is no doubt about the strength of bolts and the quality of manufacturing, why? First, the reasons for loosening 1. Physiochemical tests on Loosen. The test results are as follows: steel No. 45, hardness HB225 ~ 242, tensile strength σ_b = 760 ~ 820N / mm ~ 2, yield strength σ_s = 550 ~ 600N / mm ~ 2. The national standard GB3098.1-82 “Fastener Mechanical Properties” provides 8.8 bolts HB240 ~ 310, σ_b = 800 ~ 1000N / mm ~ 2, σ_s = 640 ~ 660N / mm ~ 2, and emphasizes the performance level markings. Obviously, the installation of high strength bolts can not meet the design requirements. 2. Check the strength of the bolt. According to the maximum output torque reducer and the machine turns the ground when the driving wheel production