I 摘要 本文首先介绍了起重机的概念和分类，在国内外的发展概况，以及起重机的现代设 计方法。接着对桥式起重机的特点、分类以及构造进行了详细的叙述。其中，本次设计 的是桥式起重机小车的主起升机构，主起升机构的起重量大，是用以起吊重物的机构。 它是桥式起重机的重要组成部分。本次设计的起升机构选用闭式的传动方案，在选用的 半齿联轴器及带制动轮的半齿联轴器中用一根高速浮动轴联接，并且为了防止在运作中 高速浮动轴突然断裂而制动不了卷筒，另外选用了制动器来制动卷筒；选择合适的减速 器以及电动机等。 由于现代工业的迅速发展和国内外市场竞争的加剧，起重机在现代化生产过程中的 应用越来越广，作用也越来越大，对起重机的要求也相应的越来越高了。因此起重机的 设计方法需不断的充实、完善，使设计出的起重机更符合实际使用工况，更注重功能化、 经济性和可靠性。 本次的毕业设计运用多种起重机的现代设计方法，特别是运用计算机辅助设计 （CAD）的方法，在计算机上将桥式起重机起升机构的设计图纸CAD化，大大提高了设计 的效率，节省时间。 关键词 桥式起重机；小车；起升机构；设计II Abstract This paper first introduces the concept of a crane and the cranes classification, the developments at home and abroad, and the cranes modern design methods. Then it describes in detail in the features、the classification and the structure of the bridge crane. In which, this time is designing the main hoisting mechanism of the small car of the bridge crane, the main hoisting mechanism from hoisting weights, which is used for hoisting heavy objects . It is an important component of the bridge crane. The design of the hoisting mechanism chooses the closed transmission programme, in the selection of the semi-gear coupling and the semi-gear coupling with break round using a high-speed floating-axis connection, and in order to prevent the operation of the high-speed floating-axis suddenly rupture that can not brake the reel, in addition to choose brakes to brake the reel; then chooses a suitable motor and reducer, and so on. Because of the rapid development of modern industry and the market competition intensifies at home and abroad, crane is used more widely in the modernization of the production process , the role of the crane is growing, also the corresponding requirements of the crane increase. So the design of the crane needs to constantly enrich and improve, that the designed crane can more meet the actual use conditions, and pay more attention to functional, economic and reliability of the crane. This graduation design uses a variety of the cranes modern design methods, in particular the computer-aided design methods（CAD）, in addition, making the hoisting mechanism of the bridge crane in the CAD design drawings way with the computer, greatly improve the efficieney of the design and save time. Keywords bridge crane small car hoisting mechanism designI 目 录 1 绪论 .1 1.1 概论 .1 1.2 起重机的分类 .1 1.3 国内外起重机的发展概况和发展动态 .2 1.4 起重机的现代设计方法概述 .3 2 桥式起重机 .7 2.1 桥式起重机的特点 .7 2.2 桥式起重机的分类 .7 2.3 桥式起重机的构造 .8 2.4 桥式起重机小车的特征 .9 3 基本参数的确定 .11 3.1 基本参数 .11 3.2 桥式起重机主起升机构主要参数确定 .12 4 起升机构的传动方案 .13 4.1主起升机构传动方案的类型 .13 4.2主起升机构传动方案的确定 .17 5 起升机构主要零部件的计算 .18 5.1 钢丝绳的选择 .18 5.1.1钢丝绳所受最大静拉力的计算 .18 5.1.2选择钢丝绳 .19 5.2 滑轮、卷筒的计算 .19 5.2.1滑轮、卷筒最小直径的确定 .