阿特拉斯工程师定级液压4

Workassignments1.Whatarethefourmostcommontypesofsystemforenergytransfer?能量传输的四种形式是Answer:________________________________________________________________________________________________________________________________________________________________________________________________________________________________2Whatthreepartsareinallsystemsofenergytransfer?Writethenamesineachrespectivebox!能量传输系统的三个组成部分是什么，写下它们的名字3Whatismeantbythetermhydraulics液压这个词的意思是什么?Answer:________________________________________________________________________________________________________________4.Inwhichthreeformscanallsubstancesoccur物质有哪三种状态?Answer:________________________________________________________________________________________________________________________________________________________________________5.Whenarehydraulictransmissionsystemssuitableorunsuitable?Makenotesbelow,bepreparedtojustify.液压传动系统何时适用何时不适用，根据下面的条件进行判断Whenthedistanceisshortorlong?传输距离近还是远时？_______________________________________________Whenlargeforcesareneeded?需要很大的力时？_______________________________________________Whentheenvironmentalrequirementsarehigh?环境要求高时？_______________________________________________6.Whichtechnologyisusedfrequentlytoobtainlongsignaldistances(i.e.alongwaybetweentheleverandvalveinahydraulicsystem?)为了实现长距离的信号控制经常应用什么技术（如液压系统中控制杆和阀时间的距离很远时）Answer:_____________________________________________________________7.Whyiscleanlinesssoimportantwhenworkingonhydraulicsystems?对液压系统工作时为什么洁净度是如此重要？Answer:_____________________________________________________________8.Statetwoadvantagesofhydraulicmotorscomparedwithothermotors!写出液压马达和其它马达相比的两个优点Answer:_____________________________________________________________9.Statetwoadvantagesofhydrauliclinearmotors(i.e.cylinders)comparedwithothertypesoflinearmotor!写出直线液压马达（油缸）和其它直线马达相比的2个优点Answer:__________________________________________________________________________________________________________________________Workassignments1Trytoanswerthefollowingquestionswithoutlookingatthepreviouspage!1TheunitforforceisdesignatedbyN,whatdoesNstandfor?力的单位定义为N，N代表什么？Answer:_________________________.2Howistheconceptofpressuredefined?压力（压强）是如何定义的？ٛweightperunitofarea单位面积上的重量ٛforcepernewton力每牛顿ٛforceperunitofarea单位面积上的力3Whatisthebasicunitforpressurecalled?压强的基本单位是什么？Answer:_________________________4Whichletterisusedtodesignatepressure?压强用什么字母标示？Answer:_________________________ٛ5Howisworkdefined?功是如何定义的？ٛforcexdistance力x距离ٛforcextime力x时间ٛpressurexdistance压强x距离6Whichletterisusedtodesignatework?功用什么字母来表示Answer:_________________________7Whatisthebasicunitforpoweroutput?输出功率的基本单位是什么Answer:_________________________8Howispoweroutputdefined输出功率是如何定义的?a)†forceperunitoftime单位时间的力b)†pressureperunitoftime单位时间的压力c)†workperunitoftime单位时间的功Workassignments2Trytoanswerthefollowingquestionswithoutlookingatthepreviouspage!1.Whatiscompressibilityameasureof?可压缩性是测量什么的Howeasilyagasmouldsitselfaccordingtothesurroundings依照环境温度气体成型的难易程度Howmuchasubstancecanbepressedtogether物体可压缩的多少Howmuchforceahydraulicfluidcantransfer液压油可传递的力的大小2.WhenthepistonispresseddownwithforceFapressurearisesinthefluid.Whereisthepressuregreatest?当以力F压下活塞，瓶内的液体压力增加，那个地方的压力最大？Answer:____________________________3Whichofthefluidsisstatic?那一个是静态的液体4Whereinthelinesystemistheflowspeedgreatest?PutanXintherightbox!管路中那一点的流速最大，在相应的方块中标X!5.Whatisvolumeflowrate?什么是流量thevolumeoffluidpassingviaacross-sectioninthelineperunitoftime单位时间流过管子横截面的液体的体积thespeedwithwhichthefluidpassesthroughtheline液体流过管子的速度thetimeittakesforacubicmetreoffluidtopassviaacross-sectionoftheline1立方米液体通过管子横截面所需要的时间6Withwhichunitsshouldvolumeflowratebestated?流量的单位是Answer:______________________________7Whatfactorsdeterminehydraulicpoweroutput?决定液压输出功率的因素是什么Answer:______________________________8Statethefourfactorsthatincreasethefrictioninahydraulicsystem!写出4个增大液压系统摩擦力的因素Answer:______________________________AB9.HydrauliccylinderAhasthreetimesaslargeapistonsurfaceareaascylinderB.WithhowmuchforcedoescylinderAact?Thepressuretobothcylindersisequallyaslarge液压油缸A的活塞面积是油缸B的3倍，要在油缸A上施加多大的力才能使两个油缸内的压强相同？Answer:___________________________________10.Supposethatyouknowamotor'storqueandatwhatspeedthemotordevelopsthetorque.Whatcanyoucalculatewiththatinformation?假设你知道马达的力矩和马达产生力矩时的转速，根据这些信息你可以计算出什么？Answer:___________________________________11Whatistherelationshipcalledbetweenthepoweroutputthatisinputintoahydraulicsystemandthehydrauliceffectiveoutput?液压系统的输入功率和液压系统的有效输出功率之间的关系是什么？Answer:___________________________________Workassignments1.Ahydrauliccylinder(jack)shouldbeabletoliftacarthatweighs1250kg.Whatforceisrequired?一个液压油缸（千斤顶）要能够举起一个重1250KG汽车，需要多大的力Showthecalculationsbelow!写下计算过程Answer:_____________________________________2.Whatisthepressureofthehydraulicfluidifthecylinderisloadedwitha500kgload?Thepistonareais0.5dm2.假设油缸负载重物为500kg，活塞的面积是0.5dm2,液压油的压力是多少Showthecalculationsbelow!写下计算过程Answer:_____________________________________3.Whatisthepressureofthehydraulicfluidifthecylinderisloadedwith200kg?Thepiston'sdiameteris6cm.