专业英语16-19.docx

16.Couplings
Vocabulary:
coupling[]联接器
couple[]连合,连接
adjacent[]邻近的
semipermanent[]非永久性的
restore[]恢复
emergency[]紧急情况
exceptional[]异常的
plant[]工厂、车间、设备
propeller[]螺旋推进器
rigid[]刚性的
flange[]凸缘、法兰
attach[]缚上,系上
alignment[]对准、同轴
misalignment[]不对准、不同轴
rabbet[]槽口,榫头
projection[]凸出物
snugly[]紧贴地
deflect[]偏斜
interfere[]妨碍
intensity[]强度
flexibility[]挠性
shock[]冲击
spatial[]空间的
resilient[]有回弹力的
springy[]有弹性的
compensate[]补偿
Text:
Acouplingisadeviceforconnectingtheendsofadjacentshafts.Inmachineconstruction,couplingsareusedtoeffectasemipermanentconnectionbetweenadjacentrotatingshafts.Theconnectionispermanentinthesensethatitisnotmeanttobebrokenduringtheusefullifeofthemachine,butitcanbebrokenandrestoredinanemergencyorwhenwornpartsarereplaced.
Thereareseveraltypesofshaftcouplings;theircharacteristicsdependonthepurposeforwhichtheyareused.Ifanexceptionallongshaftisrequiredforalineshaftinamanufacturingplantorapropellershaftonaship,itismadeinsectionsthatarecoupledtogetherwithrigidcouplings.Acommontypeofrigidcouplingconsistsoftwomatingradialflanges(disks)thatareattachedbykey-drivenhubstotheendsofadjacentshaftsectionsandboltedtogetherthroughtheflangestoformarigidconnection.Alignmentoftheconnectedshaftsisusuallyeffectedbymeansofarabbetjointonthefaceoftheflanges,i.e.,ashortcylindricalprojectiononthefaceofoneflangefitssnuglyinacircularrecessonthefaceoftheotherflange.
Inconnectingshaftsbelongingtoseparatedevices(suchasanelectricmotorandagear-box),precisealigningoftheshaftsisdifficultandaflexiblecouplingisused.Thiscouplingconnectstheshaftsinsuchawayastominimizetheharmfuleffectsofshaftmisalignment.Flexiblecouplingsalsopermittheshaftstodeflectundertheirseparatesystemsofloadsandtomovefreely(float)intheaxialdirectionwithoutinterferingwithoneanother.Flexiblecouplingscanalsoservetore