1. 研究目的与意义（文献综述）

1.1 the background and significance of the topic

crane is a multi-actionlifting machine that lifts heavy objects vertically within a certain range. itis also known as crown block, hang crane, crane ^[1]. the crane isone of the seven vehicle types (cars, coaches, trucks, tractors, specialvehicles, dumpers, off-road vehicles) according to the classification ofautomobile uses ^[2].

crane’s sorts arevarious, from the angle of structure and performance perspective, it can bedivided into bridge type crane、 hoisting machinery crane, cable crane,small and light lifting crane, boom type crane four types. it can also bedivided into bridge crane, arm crane, self-propelled crane, tower crane, cablecrane and so on. from the ways of lifting, the crane can be divided into threetypes: tower crane, mobile crane and mast crane. from the kinds of drive, itcan also can be divided into the centralized drive and respectively drive,respectively drive refers to the active wheels on both sides of each with anelectric motor drive, and concentrated drive is to use an electric motor todrive the active wheels on both sides of the long shaft drive ^[3].it can be seen that the kinds of crane is wide and the application field islarge.

2. 研究的基本内容与方案

2.1 the basic content and design goals

thecontent of this design is the design of 40t bridge crane's operation mechanism.

thebridge crane trolley is an important part of the bridge crane, it is anirreplaceable kind. the trolley is made up of trolley frame, trolley runningmechanism, electrical equipment above and hoist hook, etc. ^[10].among them the car’s running mechanism is the drive mechanism of the car. whatthis topic needed to solve the problem is to determine the car transmissionscheme, and on this basis, select the check all components, and determine itsfunctions, analysis method, and determine its conclusion ^[11]. thegoal is to through the graduation design it can grasp the working principle ofbridge crane, crane's structure and design method of crane trolley car, tryingto find improvements through careful research and innovation, make thestructure more perfect, scientific and reasonable. it should compliance withenvironmental friendliness, environmental adaptability, man-machinefriendliness, maintainability, safety, installation, disassembly, recyclability ^[12]. and it should contribute to the continuous improvement of thecrane trolley.

3. 研究计划与安排

1-2(the 19th and 20th weeks of the 7th semester) determine the graduation designtopic, graduation design assignment (related parameters), and campus datacollection.

3 (1week of 8 semesters) projectconception, document retrieval and completion of the report.

(2 to3 weeks of the 8th semester) externalpractice, external data collection and completion of internship report.

4. 参考文献（12篇以上）

[2]浦维达.汽车技术基础[m].上海：上海交通大学出版社，2008

[3]胡宗武.起重机课程设计[m].北京:冶金工业出版社,1983

[4] 扬长葵.起重机械[m].北京：机械工业出版社，1982