Unit7
Hydraulic Excavators
液压挖掘机
7．1Overview概述communism
7.1.1Basic Concept基本概念
An excavator is an engineering vehicle consisting of an articulated arm(boom,stick),bucket and cab mounted on a pivot(a rotating platform)atop an undercarriage with tracks or wheels. Their design is a natural progression from the steam shovel.
挖掘机是一种由铰接臂杆（动臂和斗杆）、铲斗和安装于履带或轮式底盘上的转盘（一种旋转平台）所组成的工程机械（车辆）。挖掘机是在蒸汽铲的基础上自然发展起来的。
The history of heavy excavating machinery began in1835when the dipper shovel was invented to excavate hard soil and rock and to load trucks.Of cour,with the invention of gasoline-and diel-powered vehicles,construction equipment became even more adaptable.Most construction equipment is powered by diel engines,although electric-power,battery power,and propane tanks are ud on specialized equipment.
重型挖掘机的历史始于1835年，当时发明了拉铲式挖掘机用于开挖坚硬的土石方及装载卡车。当然，随着汽油机和柴油机车辆的发明，工程机械也变得越来越适用。虽然在一些专用设备上使用了电力驱动、蓄电池驱动和丙烷气罐，然而大多数工程机械仍然依靠柴油机驱动。
Design modifications are driven by customer demand.As of2000,the two primary areas where customers would like to e more improvements are in the ea of operation and the operator's comfort.The need for simple operation is forced by the fact that there are fewer skilled operators in the marketplace.And operations and reliability are both improving becau of the
continuing integration of electronics,automation,better engine technology,and on-board diagnostics.It
is now up to the manufacturers to cost-effectively incorporate improvements.
客户要求推动着设计的改进。自从2000年以来，客户所期望改进的两个主要方面为操作方便性和操作舒适性。操作简单的要求迫于在市场中很难找到熟练操作人员的事实。由于电子技术、自动化、高性能发动机技术、在线诊断技术的不断集成，操作性和可靠性均得到了不断的改进。目前，制造商在进行各种成本效益方面的改进。
face to face
7.1.2Applications应用helpme
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1.digging and loading挖掘装载；
2.stonework石方工程；
3.mining engineering采掘工程；
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4.port operation港口作业；reed college
6.t ake down old buildings建筑拆除；
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8.under water operation水下作业；
9.pipe laying铺设管道；
10.hoisting heavy object起吊重物；11.breaking pavement破碎路面；12.clear up side slope整理边坡；13.watercour clearance疏通水道；14.removal treatment清理作业
7.1.3Types类型
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1.mini type excavator微型挖掘机；
2.small type excavator小型挖掘机；
4.large type excavator大型挖掘机；
5.wheel excavator轮式挖掘机；
6. large type shovel（face excavator）大型正铲挖掘机；
7.Ultra high demolition hydraulic excavator 超高层建筑物拆除液压挖掘机；
8.river channel dredging excavator河道疏浚挖掘机；
9. telescopic boom excavator伸缩臂式挖掘机；10.wetlands excavator湿地挖掘机；11.wheel backhoe loader轮式挖掘装载机；12.radio controlled excavator无线控制型挖掘机
7.2Components and Features组成与特点
7.2.1Overall Structure总体结构
1.diel engine and hydraulic system柴油机及液压系统；
2.undercarriage行走支承机构；
自学英语的方法
3.swing mechanism回转机构；
4.work equipment asmbly工作装置总成；
monday的音标5.steering and operating system转向操纵系统
7.2.2Major Components主要部件
7.2.2.1Diel Engine and Hydraulic System柴油机及液压系统
