中英文文献翻译液压传动系统设计与计算文档格式.docx

中英文文献翻译液压传动系统设计与计算文档格式.docx

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Chart1.1displacementscirculationchart

1.1.2speedscirculationchartv—t（orv—L）

Intheprojectthehydrauliccylindermovementcharacteristicmayinduceisthreekindoftypes.Thechart1.2isthreekindoftypeshydrauliccylindersv—tchart,thefirstkindoflikechart1.2centersolidlinesshow,thehydrauliccylinderstartstomaketheuniformacceleratedmotion,thenuniformmotion,

Chart1.2speedscirculationchart

Finallyuniformretardedmotiontoendpoint;

Thesecondkind,thehydrauliccylinderprecedingpartlymakestheuniformacceleratedmotionintheoveralltravellingschedule,inanotheronepartlymakestheuniformretardedmotion,alsotheaccelerationvalueisequal;

Thethirdkind,thehydrauliccylinderonemostabovemakestheuniformacceleratedmotionintheoveralltravellingschedulebyasmalleracceleration,thenuniformdeceleratestothetravellingscheduleendpoint.V—tchartthreevelocitycurve,notonlyclearlyhasindicatedthreekindoftypeshydrauliccylindersmovementrule,alsoindirectlyhasindicatedthreekindofoperatingmodesdynamicperformance.

1.2mechanicalanalyses

1.2.1hydrauliccylindersloadsanddutycyclechart

1.2.1.1hydrauliccylindersloadstrengthcomputations

Whentheoperatingmechanismmakesthestraightreciprocatingmotion,thehydrauliccylindermustovercometheloadiscomposedbysixparts

（1.1）

Intheformula:

FcInordertoresistancetocutting;

FfInordertofrictiondrag;

FiForinertiaresistance;

FgForgravity;

FmInordertosealtheresistance;

FbInordertodraintheoiltheresistance.

1.2.1.2hydrauliccylinderscycleofmotionvariousstagesoverallloadstrength

Thehydrauliccylindercycleofmotionvariousstagesoverallloadstrengthcomputation,generallyincludesthestartacceleration,quicklyenters,thelaborenters,quicklydrawsback,deceleratesappliesthebrakeandsoonseveralstages,eachstageoverallloadstrengthhasthedifference.

（1）startstheaccelerationperiod:

Bynowthehydrauliccylinderorthepistonwereinfromstaticenoughtostartsandacceleratestothecertainspeed,itsoverallloadstrengthincludingguiderailfrictionforce,packingassemblyfrictionforce（accordingtocylindermechanicalefficiencyηm=0.9computation）,gravityandsoonitem,namely:

　　　　（1.2）

（2）faststage:

（1.3）

（3）thelaborentersthestage:

　　　（1.4）（4）decelerates:

（1.5）

Tothesimplehydraulicsystem,theabovecomputationprocessmaysimplify.Forexampleusesthesingleproportioningpumptosupplytheoil,onlymustcalculatethelabortoenterthestagetheoverallloadstrength,ifthesimplesystemusesthelimitingpressuretypevariabledisplacementpumporapairofassociationpumpsfortheoil,thenonlymustcalculatethefaststageandthelaborentersthestagetheoverallloadstrength.

1.2.2oilmotorsload

Whentheoperatingmechanismmakestherotarymotion,theoilmotormustovercometheoutsideloadis:

（1.6）

1.2.2.1operatingdutiesmomentofforceMe.Theoperatingdutymomentofforceispossiblyadefinitevalue,alsopossiblyasnecessarychanges,shouldcarryontheconcreteanalysisaccordingtothemachineworkingcondition.

1.2.2.2frictionmoments.Inordertorevolvethepartjournalplacefrictionmoment,itsformulais:

　（1.7）

Gisrevolvesthepartweight（N）;

Fistherubbingfactor,whenthestartforthefactor,afterthestartformovestherubbingfactor;

Risthejournalradius（m）.

1.2.2.3momentofinertiaMi.Themomentofinertiawhichinordertorevolvethepartaccelerationordecelerateswhenproduces,itsformulais:

（1.8）

εIstheangleacceleration（r/s2）;

istheaccelerationordeceleratesthetime（s）;

Jisrevolvesthepartrotationinertia（

）,

Inordertorotatetheparttheflywheeleffect（

）.

Eachkindmaylookup<

MachinedesignHandbook>

Accordingtothetype（1.6）,separatelyfiguresouttheoilmotorinaoperatingcyclevariousstagesloadsize,thenmaydrawuptheoilmotorthedutycyclechart

2determinationshydraulicsystemmainparameter

2.1hydrauliccylindersdesigncalculations

2.1.1initiallydecidesthehydrauliccylinderworkingpressure

Inthehydrauliccylinderworkingpressuremainbasiscycleofmotionvariousstagesbiggestoverallloadstrengthdetermined,inadditionbelow,butalsoneedstoconsiderthefactor:

2.1.1.1eachkindofequipmentdifferentcharacteristicandusesituation.

2.1.1.2considerationseconomiesandtheweightfactor,thepressureelectslowly,thenpartsizebig,theweightisheavy;

Thepressurechooseshighsomewhat,thenpartsizesmall,theweightislight,buttothepartmanufactureprecision,thesealingpropertyrequestshigh.

Therefore,thehydrauliccylinderworkingpressurechoicehastwoways:

One,electsaccordingtothemechanicaltype;

Two,accordingtocutstheloadtoelect.

Ifthetable2.1,thetable2.2shows.

Thetable2.1pressestheloadtochoosetheexecutionfiletheworkingpressure

Load

/N

＜5000

500～10000

10000～20000

20000～30000

30000～50000

＞50000

Workingpressure

/MPa

≤0.8～1

1.5～2

2.5～3

3～4

4～5

＞5

Thetable2.2pressesthemechanicaltypetochoosetheexecutionfiletheworkingpressure

Mechanicaltype

Enginebed

Farmmachinery

Projectmachinery

Grinder

Aggregatemachine-tool

DragonGatedigsthebed

Broachingmachine

a≤2

3～5

≤8

8～10

10～16

20～32

2.2oilmotorsdesigncalculation

2.2.1computationsoilmotordisplacement

Underoilmotordisplacementaccordingtothetypedecidedthat,

（2.1）

Tistheoilmotorloadmomentofforce（N·

m）;

Foroilmotorimportandexportpressuredifference（n/m3）;

istheoilmotormechanicalefficiency,thecommongearandtheplungermotortakes0.9~0.95,theleafblademotortakes0.8~0.9.

2.2.2computationsoilmotorneedsthecurrentcapacityoilmotorthemaximumcurrentcapacity

　　　（2.2）

istheoilmotordisplacement（m3/r）;

istheoilmotorhighestrotationalspeed（r/s）.

3hydraulicpressurepartschoice

3.1hydraulicpumpsdeterminationswithneedthepowerthecomputation

3.1.1.1determinesthehydraulicpumpthebiggestworkingpressure.Thehydraulicpressurepumpingstationmusttheworkingpressuredetermination,mainlyactsaccordingtothehydrauliccylinderintheoperatingcyclevariousstagestohavemosttremendouspressurep1,inadditiontheoilpumplosesSigmaDeltaptheoilmouthtothecylinderplacealwayspressureΣΔp,namely

（3.1）

loses,thepipelineincludingtheoilaftertheflowvalveandotherpartslocalpressuresalongtheregulationlossandsoon,beforesystempipelinedesign,mayactaccordingtothesimilarsystemexperiencetoestimate,commonpipelinesimplethrottlevalvevelocitymodulationsystemΣΔpis（2~5）×

105Pa,withthevelocitymodulationvalveandpipelinecomplexsystem

is（5~15）×

105Pa,

alsomayonlyconsiderflowsaftervariouscontrolvalvespressureloss,butignoresthecircuitryalongtheregulationloss,variousvalvesratedpressurelosesmaysearchesfromthehydraulicpressureparthandbookortheproductsample,Alsomayrefertothetable1.3selections

Thetable3.1iscommonlyused,thelowpressureeachkindofvalvepressureloses（Δpn）

Valve

Δpn（×

105Pa）

Cone-wayvalve

0.3～0.5

3～8

Crossvalve

1.5～3

2～3

3.1.2determinesthehydraulicpumpcurrentcapacityqB

Pumpsthecurrentcapacity

basisfunctionalelementoperatingcyclemustthemaximumcurrentcapacity

andthesystemdivulgesthedetermination

3.1.2.1Atthesametimewhenmorethanhydrauliccylindersmovement,thehydraulicp