摘要工程起重机是各种工程建设广泛运用的重要起重设备，是用来对物料进行起重、运输、装卸或安装等作业的机械设备，在工业和民用建筑中作为主要施工机械而得到广泛运用。它对减轻劳动强度、节省人力，降低建设成本，提高施工质量，加快建设速度，实现工程施工机械化起着十分重要的作用。目前我国是世界上使用工程起重机最大的国家之一。69997

相对于其他起重机，汽车起重机不仅具有移动方便，操作灵活，易于实现不同位置的吊装等优点，而且对其进行驱动和控制的液压系统易于实现改进设计。随着液压传动技术的不断发展，汽车起重机已经成为各起重机生产厂家主要发展对象。近年来，随着工程建设规模的扩大，起重安装工程量越来越大，吊装能力、作业半径和机动性能的更高要求促使起重机发展迅速，具有先进水平的塔式起重机和汽车起重机已成为机械化施工的主力。

本主题主要针对的功能、 组成和工作特点的汽车起重机，结合使用的起重机在国内和国外目前的现状以及发展趋势，设计中型汽车起重机可以适应内、 国际工程施工 (QY20) 传动系统。当设计传动系统、 明确设计任务和设计要求;

毕业论文关键词： 汽车起重机；传动系统；减速器；

Design of QY20 truck crane drive system

Abstract Crane is widely used in all kinds of engineering construction of important lifting equipment, is used for lifting, transportation, loading and unloading of materials or the work of mechanical equipment such as installation, in industrial and civil buildings and are widely used as the main construction machinery. In recent years, with the enlargement of the scale of engineering construction, lifting work quantity is more and more big, the hoisting capacity, higher requirements to the crane operational radius and maneuver performance development is rapid, with advanced levels of the tower crane and crane has become the main mechanical construction.

 Relative to other cranes, crane has not only mobile and convenient, flexible operation, easy to realize the advantages of different location of hoisting, and carries on the drive and control of hydraulic system is easy to realize design improvements. With the continuous development of hydraulic transmission technology, truck crane crane manufacturers have become the main development object.

This topic mainly aimed at the function, composition and the working characteristics of truck crane, combining the use of the crane at home and abroad present situation and development trend, design a medium-sized truck crane can adapt to domestic and international engineering construction (QY20) drive system. When designing the machine drive system, the clear design task and design requirements; 

Keywords ：　Drill Machine; Draw Equipment; Speed Reducer;　

目录

摘　要 I

Abstract II

目录 III

第一章 绪论 6

1.1起重机械在国民经济中的作用及其工作特点 6

1.2国内汽车起重机的发展趋势以及发展概况 7

1.3国外汽车起重机发展概况及发展趋势 8

1.4本课题的研究内容与意义 10

  1.5小结 10

第二章QY20汽车起重机的总体结构 11

2.1 汽车起重机的总体结构 11

  2.2 小结