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一、起重机的工作特征起重机具有短暂而重复的工作特征。各工作机构在工作时作周期性的运动,作用其上的载荷也是变化的。一个机构在工作周期内,有工作阶段和休息阶段;在工作阶段里,又分有载行程和无载行程;有载行程又分满载和不满载。有的起重机日夜三班工作,有的只工作一班,有的甚至一天只工作几次,表现出不同的工作繁忙程度。各工作机构由于短暂而重复地工作,所以起动和制动频繁,因此,都具有动力冲击作用,并且由于工作速度不同,这种冲击的程度也不一样。因为载荷的波动、繁忙的程度和冲击的程度不一样,结果是同一名义起重量的起重机,其静的和动的实际受力是不一样的。在起重机械中根据这种工作的特征,将起重机分成轻、中、重和特重四种类型,在设计计算时分别予以不同考虑。强度条件式当然
First, the crane’s working characteristics Crane has a short and repeated work characteristics. Each working organization makes periodic movements while working, and the load on it also changes. In a work cycle, an organization has a work phase and a rest phase; in the work phase, it also has a load and a no-load travel; the loaded travel is divided into full load and dissatisfaction. Some cranes work three shifts day and night, some only work one shift, and some even work several times a day, showing different levels of work. Since each working mechanism works briefly and repeatedly, it is frequently started and braked. Therefore, it has a dynamic impact, and the degree of the impact is also different due to different working speeds. Because the fluctuation of the load, the degree of busyness and the degree of impact are not the same, the result is that the crane with the same nominal weight is not the same as the actual stress of static and dynamic lifting. According to the characteristics of this kind of work, the crane is divided into four types of light, medium, heavy and special weights in the hoisting machinery, which are considered differently in the design calculation. Intensity conditional course