轮机英语unit25Anchorwindlassa

Lesson25AnchorwindlassandMooringwinch锚机和绞缆机,Anchorhandlingequipment,Thewindlass（锚机）istheusualanchorhandlingdevicewhereonemachinemaybeusedtohandlebothanchor.,Amorerecentdevelopment,particularlyonlargevessels,isthesplitwindlasswhereonemachineisusedforeachanchor.,Oneunitofasplitwindlass(分离式锚机）isshowninFig.25-1.,Therotatingunitsconsistofacablelifter(锚链轮）withshapedsmug（凸起）togriptheanchorcable（锚链）,amooringdrum（绞缆筒）forpayingout（放松）orlettinggo（放出）ofmooringwiresandawarpendforwarpingduties.,Eachoftheseunitsmaybeseparatelyengaged（啮合）ordisengagedbymeansoradogclutch（牙嵌离合器）,althoughthewarpendisoftendriveninassociationwiththemooringdrum.,Aspurgear（正齿轮）assemblytransmitsthemotordrivetoshaftwherethevariousdogclutchesenablethepowertake-off.,Separatebandbrakes（独立式刹车）arefittedholdthecablelifterandthemooringdrum（绞缆筒）whenthepowerisswitchedoff.,Thecablelifterunit（锚链轮）,showinFig.25-1,ismountedsoastoraiseandlowerthecablefromthespurlingpipe（锚链管）,whichisatthetopandcenterofthechainorcablelocker（锚链舱）.,Detailsofthesnugs（卡块）usedtogripthecableandbandbrake（带式刹车）canbeseen.,Anchorcapstans（起锚绞盘）areusedinsomeinstallationswherethecablelifterrotatesaboutaverticalaxis.,Onlythecablelifterunitislocatedondeck,thedrivingmachinery（驱动机械）beingonthedeckbelow.,Awarpingendorbarrelmaybedrivenbythesameunitandispositionednearthecablelifter.,Theefficientworkingoftheanchorwindlassisessentialtothesafetyoftheship.Ananchorwindlasscanexpecttofulfill（满足）thefollowing:,1.Thewindlasscablelifterbrakesmustbeabletocontroltherunninganchorandcablewhenthecablelifterisdisconnectedfromthegearduring“lettinggo”（放锚）.,Averagecablespeedsvarybetween5-7m/secduringthisoperation,2.Thewindlassmustbeableheaveacertainweightofcableataspecifiedspeed（额定转速）.,This“fullload”dutyofthewindlassvariesbutiscommonlybetween4and6timestheweightofoneanchor,thespeedofhaulbeingatleast9m/minupto15m/min.,3.Thebrakingeffort（刹车效果）obtainedatthecableliftermustbeatleastequalto40percentofthebreakingstrengthofthecable.,Mostanchorhandingequipmentsincorporate（包含）warpendsformooringpurposes（系泊）andlinespeedsofupto0.75to1.00m/secarerequired.,Themostconventionaltypesofequipmentinuseareasfollows.,Windlasses,Thisequipmentisself-contained（独立的）andnormallyoneprimemoverdrivestwocableliftersandtwowarpends（绞缆端）,thelattermaynotbedeclutchable（离合装置）and,ifso,rotatewhenthecableliftersareengaged.,Thereissomevariationindetaildesignofcableliftersandintheirdrives.,Duetothelowspeedofrotationrequiredofthecablelifterwhilstheavinganchor,(345r/min)ahighgearreduction(齿轮减速机构）isneededwhenthewindlassisdrivenbyahighspeedelectricofhydraulicmotor.,Thisisgenerallyobtainedbyusingahighratiowormgear（涡轮）followedbyasinglestepofspurgears（单级正齿轮）betweenthewarpendshaftandcablelifters.,Alternatively,multistepsofspurgearsareused.,Capstans（起锚机）withthistypeofequipmentthedrivingmachineryissituatedbelowdeckandthecableliftersaremountedhorizontallybeingdrivenbyverticalshafts.,Mooringwinches,Mooringwinchesprovidethefacilityfortensioningthewireuptothestallingcapacity（堵转转矩）ofthewinch（绞车）,usually1.5timesfullload（全负荷）,thereaftertheloadisheld（握持）bytheprimemoverbrakeorbarrelbrakewhenthepowerisshutoff.,Thewinchcannotpayoutwireunlessthebrakeisoverhauled（超越）orrecoverwireunlessmanuallyoperated,thuswiresmaybecomeslack.,Themajorityofautomaticmooringwinches（自动系缆机）arespurgeared（正齿轮）toimprovethebackwardefficiencyofthegeartrainforrendering,thegearing（齿轮机构）andbearingsbeingtotallyenclosedandlubricatedfromtheoilsump.,Onlargermooringwincheswhereabarrelbrakeisfitted,itisnowcommonpracticetodesignthebraketowithstandthebreakingstrengthofthemooringwire.,Wormgeared（涡轮蜗杆）automaticmooringwinchesareuncommon,asthemultistart（多次起动）featurerequiredtoimprovegearefficiencyreducesthemainadvantageofthewormgeari.ethehighgearratio（传动比较高）.,Wincheswithvariousarrangementsofbarrelsaretheusualmooringequipmentusedonboardships.,AmooringwinchisFig.25-2wherethevariouspartscanbeidentified.,Thewinchbarrelordrumisusedforhauling（收紧）inorlettingoutthewiresorropeswhichwillfastentheshiptotheshore.,Thewarpendisusedwhenmovingtheshipusingropesorwiresfastenedtobollards（系缆桩）ashoreandwraparoundthewarpendoftilewinch.,Theconstructionofamooringwinchwillnowbeexamined,againwithrespecttoFig.25-2.,Themotordriveispassedthroughaspurgeartransmission（直齿轮传动机构）,aclutchandthustothedrum（卷筒）andwarpend.,Asubstantial（坚实的）framesupportstheassemblyandabandbrakeisusedtoholdthedrumwhenrequired.,Thecontrolarrangementsforthedrivemotorpermitforwardorreverserotationtogetherwithaselectionofspeedsduringoperation.,Modernmooringwinchesarearrangedasautomaticselftensioningunits（自动张紧装置）.,Theflowofthetides（潮）orchanges