BRT快速公交从动车桥设计

车辆工程专业毕业论文，论文编号:JX889  论文字数:10312.页数:29

 摘     要
 BRT是快速公交系统（Bus Rapid Transit）的简称，是一种来源于巴西库里蒂巴介于快速轨道交通（Rapid Rail Transit，简称RRT）与常规公交（Normal Bus Transit，简称NBT）之间的新型公共客运系统，是一种大运量交通方式，通常也被人称作“地面上的地铁系统”。它是利用现代化公交技术配合智能交通和运营管理，开辟公交专用道路和建造新式公交车站，实现轨道交通运营服务，达到轻轨服务水准的一种独特的城市客运系统。
 低地板客车技术保证乘客更为快速、便捷的上下车，实现了公交客车在车站平均停留时间缩短一半。由此，城市公交客车运营速度及效率得以大幅提高，给类似北京这样人口上百万的国际大都市的公共交通带来了巨大深远的影响。快速公交系统理念为公共交通在应对日益增长的私人交通需求方面提供了一个真正可行的解决方案。得益于快速公交系统及其所应用的低地板客车技术，每天更多的市民在更短的时间内往返于市中心和城郊之间。
 本次设计首先明确概述设计动机、目的、背景以及方法等，然后介绍了BRT快速公交的特性和一些基本的情况，了解国内外BRT快速公交的发展状态，接着我们分析设计BRT快速公交前桥组成部分，主要涉及前桥大梁，主销，主销的设计。前梁采用工字形断面，可保证其质量最小而在垂向平面的刚度大、强度高。为提高其抗弯强度，其较长的中间部分相对两端向下偏移一定距离。为提高其抗扭强度，两端与拳部相接的部分采用方形断面，而靠近两端使拳部与中间部分相联接的向下弯曲部分则采用两种断面逐渐过渡的形状。中间部分的两侧还要锻造出钢板弹簧支座的加宽支承面；转向节可采用组焊式结构；主销采用圆柱实心型；转向节推力轴承承受作用于汽车前梁上的重力，为减小摩擦使转向轻便可采用滚动轴承；主销上、下轴承承受较大的径向力，采用滚针轴承结构；轮毂轴承由一对单列圆锥滚子轴承组成，刚度较大，可承受较大的负荷；左、右轮胎螺栓均采用右旋螺纹。
最后，对本次毕业设计进行了总结。
 
关键词：BRT  快速公交  低地板前桥 

Abstract
 BRT is the shortcut for Bus Rapid Transit. It was born in Brazil and has a crossfunktion between RRT (Rapid Rail Transit) and NBT ( Normal Bus Transit). For its strong capability of transition it is also called “the subway above the road”. It combines the technology like intelligence transit, modern manage systems and so on, and has exclusive road and bus station, which make it possible run like RRT system.
 Low floor technology make it more rapid and convenient when getting on and off. The time can be half time of normal way. Thus the transition can be much more effective, which can change the situation greatly in metropolis like Beijing. It provide real solution to the rising challenges. Due to the low floor technology, more and more citizen transit between urban area and suburb area every day.
  This design firstly define the background and mission. And then introduce BRT property and basic information, like the develop situation inland and foreign countries. Then I design the components like axle, steering knuckle, pin. Before the girder-shaped cross section, can guarantee its quality in the vertical plane of minimum stiffness, high strength. To improve the bending strength, its long ends down the middle part of the relative migration distance. To enhance the torsional strength, ends with the fist part of the Department of phase with square cross section, but near the ends of the Ministry to punch down the middle to link the two sections by bending part of the gradual transition of the shape. The middle part of forging a leaf spring on both sides but also widen the bearing surface bearing; steering knuckle can be used welding structure; the main use of cylindrical solid pin type; steering knuckle thrust bearing to withstand the role of gravity in the car before the beam for reduce friction bearing can be used to turn light; kingpin upper and lower bearings to withstand higher radial force, use of needle roller bearings; wheel hub bearings by a pair of single row tapered roller bearing composition, stiffness, can withstand higher load; left and right tires bolt right hand thread are used. Finally I summarize the design process.
Keywords: BRT   Low Floor   Transit

目  录
摘  要 I
Abstract Ⅱ
目  录 Ⅲ
第一章  绪 论 1
 1.1  选题的背景与意义 1
 1.1.1低地板前桥概念 1
 1.1.2 低地板公交现状及趋势 1
 1.1.3 BRT可行性分析 2
 1.2  研究内容 3
 1.3  研究的方法与技术路线 3
 1.4  本章小结 4
第二章  BRT快速公交从动车桥设计 5
第三章  前梁设计 7
 3.1  前梁载荷计算 7
 3.1.1 紧急制动 8
 3.1.2 侧滑 8
 3.1.3 越过不平路面 9
 3.2  弯矩及扭矩计算 10
 3.2.1 紧急制动 10
 3.2.2 侧滑 11
 3.2.3 越过不平路面 11
 3.3  应力计算 13
 3.4  本章小结 14
第四章  转向节设计 15
 4.1  截面系数计算 15
 4.2  弯矩计算 15
 4.3  应力计算 16
 4.4  本章小结 16
 
第五章  主销设计 17
 5.1  载荷计算 17
 5.2  弯矩计算 19
 5.3  应力计算 19
 5.4  本章小结 20
第六章 总结 21
参考文献 22
致  谢 23