1,MC pulley kulephera mawonekedwe ndi kusanthula chifukwa　

　　MC nayiloni chuma amakhala polyamide mankhwala ndipo tichipeza covalent ndi maselo zomangira, mwachitsanzo intra-maselo womangidwa ndi covalent zomangira ndi yapakati-maselo womangidwa ndi maselo zomangira.Kapangidwe kazinthu kameneka kamakhala ndi ubwino wosiyanasiyana monga kulemera kopepuka, kukana kuvala, kukana dzimbiri, kutchinjiriza, etc. Ndi pulasitiki yaumisiri yomwe imagwiritsidwa ntchito kwambiri [1].　

　　Pulley ya MC nayiloni yogwiritsidwa ntchito pakhomo la chishango cha Tianjin Metro Line 2 idzakhala ndi mitundu iwiri ya kulephera pakapita nthawi: (1) kuvala pamphepete mwa kunja kwa pulley;(2) chilolezo pakati pa mphete yamkati ya pulley ndi kunyamula.

Zifukwa za mitundu iwiri yomwe ili pamwambayi ikulephera, kusanthula kotsatiraku kumachitika.　

　　(1) Thupi lachitseko silili lolondola, ndipo malo a pulley adzakhala olakwika panthawi yogwira ntchito, zomwe zidzachititsa kuti m'mphepete mwa kunja muveke, ndipo mphamvu ya mkati mwa pulley ndi kubereka zidzawonekera mbali zosiyanasiyana za kupsinjika kwa danga.　

　　(2) njanji si yowongoka kapena pamwamba silathyathyathya, kuchititsa kuvala kunja.　

　　(3) Chitseko chikatsegula ndi kutseka, chitseko chotsetsereka chimayenda, gudumu lotsetsereka limakhala ndi katundu wa cyclic kwa nthawi yayitali, zomwe zimayambitsa kutopa, gudumu lamkati la pulley limakhala lopunduka ndipo kusiyana kumapangidwa.　

　　(4) chitseko pa mpumulo, pulley wakhala akunyamula kulemera kwa khomo kutsetsereka, kwa nthawi yaitali kunyamula katundu wokhazikika, chifukwa cha zokwawa mapindikidwe.　

　　(5) Pali kuuma kusiyana pakati pa kubala ndi pulley, ndipo nthawi yaitali extrusion kanthu adzatulutsa mapindikidwe ndi chifukwa kulephera [2].　

　　2 MC pulley kuwerengera moyo　

　　MC nayiloni pulley ndi polima dongosolo la zipangizo zomangamanga, mu ntchito yeniyeni ntchito, ndi kutentha komanso udindo wa katundu, dongosolo maselo a mapindikidwe osasinthika, amene pamapeto pake kumabweretsa chiwonongeko cha zinthu [3].　

　　(1) Poganizira za kutentha: ndi kusintha kwa kutentha mkati mwa chilengedwe, mgwirizano wotsatirawu ulipo pakati pa zinthu zakuthupi za zida zamagulu ndi nthawi yolephera, zomwe zimafotokozedwa ngati ntchito ya　

　　F (P) = Kτ (1)　

　　pomwe P ndi mtengo wakuthupi ndi wamakina;K ndi zomwe zimachitika nthawi zonse;τ ndi nthawi yokalamba.　

　　Ngati zinthuzo zatsimikiziridwa, ndiye kuti mtengo wa P wa magawo akuthupi azinthu izi umatsimikiziridwa, ndipo zotsimikizika zamphamvu ndi kupindika zimayikidwa pamwamba pa 80%, ndiye kuti ubale pakati pa nthawi yovuta ndi K nthawi zonse ndi.　

　　τ=F(P)/K (2)　

　　Kukhazikika kwa K ndi kutentha kwa T kumakwaniritsa ubale wotsatirawu.　

　　K=Ae(- E/RT) (3)　

　　kumene E ndi mphamvu yotsegula;R ndiye mpweya wabwino wokhazikika;A ndi E ndi zokhazikika.Kutenga logarithm ya mafomu awiri omwe ali pamwambapa masamu ndikusintha mapindidwe, timapeza　

　　lnτ = E/(2.303RT) C (4)　

　　Mu equation yomwe yapezedwa pamwambapa, C ndiyokhazikika.Malingana ndi equation yomwe ili pamwambayi, imadziwika kuti pali mgwirizano wabwino wofanana pakati pa nthawi yovuta ndi kutentha .Kupitiliza ndi kusinthika kwa equation yomwe ili pamwambapa, timapeza.　

　　lnτ=ab/T (5)　

　　Malinga ndi chiphunzitso cha kusanthula manambala, zosinthika a ndi b mu equation pamwambapa zimatsimikiziridwa, ndipo moyo wovuta pa kutentha kwautumiki ukhoza kuwerengedwa.　

　　Tianjin metro line 2 kwenikweni ndi siteshoni yapansi panthaka, chifukwa cha ntchito ya chitseko cha chishango ndi kuwongolera mphete, kutentha komwe pulley imakhala yokhazikika chaka chonse, kuyesedwa potenga mtengo wapakati wa 25.°, titatha kuyang'ana tebulo, tikhoza kupeza = -2.117, b = 2220, kubweretsa t = 25° mu (5), tikhoza kulowaτ = 25.4 zaka.Tengani chitetezo cha 0.6, ndikupeza mtengo wachitetezo wazaka 20.3.　

　　(2) kulemedwa pa kusanthula moyo kutopa: kusonyeza pamwamba kuganizira kutentha kwa pulley moyo mawerengedwe, ndi ntchito kwenikweni, pulley adzakhalanso ndi udindo wa katundu, mfundo yake ndi: polima molecular kapangidwe pansi. Zochita zakusinthana kwa katundu zinapanga kusinthika kosasinthika ndi kusinthika kwa mawonekedwe a maselo, ogwira ntchito pamakina omwe amagwira ntchito ya unyolo wa maselo, kupanga kasinthasintha ndi kupotoza, kupanga mapangidwe a siliva ndi shear band siliva, kuwonetsera kutopa, ndi kudzikundikira kwakukulu. chiwerengero cha alternating mkombero Mumakonda, chitsanzo siliva pang'onopang'ono kukodzedwa, kupanga mng'alu, ndi lakuthwa anakulitsa, ndipo potsiriza zinachititsa kuti fracture wa zinthu kuwonongeka.　

　　Mu kuwerengera moyo uku, kusanthula moyo kumachitika pansi pazikhalidwe za malo abwino, mwachitsanzo, njanjiyo ndi yathyathyathya ndipo khomo la thupi limakhala lathyathyathya.　

　　Choyamba, ganizirani za kuchuluka kwa katundu pa moyo: chitseko chilichonse chotsetsereka chimakhala ndi ma pulleys anayi, pulley iliyonse imagawana gawo limodzi mwa magawo anayi a kulemera kwa chitseko, mutayang'ana kuti chitseko chotsetsereka ndi 80kg, mphamvu yokoka ya chitseko ingapezeke: 80.× 9.8 = 784 N.　

　　Kenako gawanani mphamvu yokoka pa pulley iliyonse monga: 784÷ 4 = 196 N.　

　　M'lifupi mwa chitseko chotsetsereka ndi 1m, ndiye kuti, nthawi iliyonse chitseko chikutsegulidwa ndi kutsekedwa kwa 1m, ndiyeno kuyeza m'mimba mwake mwa pulley ndi 0.057m, akhoza kuwerengedwa ngati kuzungulira kwake: 0.057× 3.14 = 0.179m.　

　　Kenako chitseko chotsetsereka chimatsegulidwa kamodzi, kuchuluka kwa matembenuzidwe omwe pulley akuyenera kupita atha kutengedwa: 1÷ 0.179 = 5.6 kutembenuka.　

　　Malinga ndi zomwe dipatimenti Yoyang'anira Magalimoto amaperekedwa, kuchuluka kwa magalimoto kumbali imodzi ya mwezi ndi 4032, yomwe ingachokere ku kuchuluka kwa kuthamanga patsiku: 4032÷ 30 = 134.　

　　m'mawa uliwonse siteshoni amayesa chitseko chophimba pafupifupi 10, kotero chiwerengero chonse cha sliding khomo mayendedwe patsiku ndi: 134 10 = 144 nthawi.　

　　khomo lotsetsereka kamodzi, pulley kuti atembenuke 11.2, khomo lotsetsereka tsiku limakhala ndi 144 switch cycle, kotero chiwerengero chonse cha pulley chimayenda tsiku: 144× 5.6 = 806.4 kutembenuka.　

　　Pamphuno iliyonse ya pulley, tiyenera kukhala pansi pa kuzungulira kwa mphamvu, kuti tipeze mphamvu yake pafupipafupi: 806.4÷ (24× 3600) = 0.0093 Hz.　

　　Pambuyo poyang'ana deta, 0.0093 Hz mafupipafupi awa akufanana ndi chiwerengero cha maulendo pafupi ndi infinity, kusonyeza kuti nthawi zambiri katunduyo ndi wotsika kwambiri, apa sakuyenera kuganizira.　

　　(3) lingaliraninso za kupsinjika kwa moyo: mutatha kusanthula, kulumikizana pakati pa pulley ndi njira yolumikizirana pamtunda, pafupifupi dera lake: 0.001.1× 0.001.1 = 1.21× 10-6m2　

　　Kutengera kupanikizika kwa metric: P = F / S = 196÷ 1.21× 10-6 = 161× 106 = 161MPa　

　　Mukayang'ana tebulo, kuchuluka kwa mikombero yofanana ndi 161MPa ndi 0.24×106;malinga ndi nambala yozungulira pamwezi nthawi 4032, kuchuluka kwa zozungulira pachaka zitha kupezeka: 4032×12 = 48384 nthawi　

　　Ndiye titha kupeza kukakamizidwa uku kofanana ndi moyo wa pulley: 0.24× 106÷ 48384 = zaka 4.9