Waɗanne abubuwa ne suka shafi ɗaukar nauyi?

Dalilin ɗaukar fitarwa shine sanya zoben ciki na ciki ko zoben waje wanda ya kafe tare da shaft ko kwasfa, don kauce wa ɓatanci na sihiri ko jujjuyawa akan shimfidar juna.

Wannan nau'in zamiya mara kyau (wanda ake kira creep) zai haifar da dumama mara kyau, sanya kayan farji (wanda zai sa hoda baƙin ƙarfe ya mamaye mamayewar ciki) da rawar jiki, wanda zai sa ɗaukar nauyin ya kasa taka rawa.

Sabili da haka, don ɗaukar nauyi, saboda juyawar kaya, gabaɗaya ya zama dole a bar zobe tare da tsangwama, don ya zama an daidaita shi da shaft ko harsashi.

Tolearamar girma na shaft da gidaje

An daidaita girman haƙurin shaft da ramin gidaje na tsarin awo ta hanyar GB / t275-93 "rollaƙƙarfan birgima da shaft da dacewa da gidaje". Za'a iya ƙayyade fitowar ɗaukar kaya da shaft ko gidaje ta zaɓin haƙuri mai girma.

Zaɓin ɗaukar nauyi

Zaɓin ɗaukar fitarwa gabaɗaya ana aiwatar da shi bisa ga ƙa'idodi masu zuwa.

Dangane da shugabanci da yanayin nauyin da ke aiki a kan ɗaukar kuma wane gefen na zoben ciki da na waje suke juyawa, za a iya raba kayan da kowane zoben ke ɗauke da su zuwa lodi mai juyawa, tsayayyen kaya ko mara nauyi. Matsakaiciyar fitarwa (fitarwa ta dace) ya kamata a karɓa don ɗaukar nauyi mai juyawa da ɗaukar mara nauyi, kuma sauyin miƙaƙƙen motsi ko ƙwanƙwasa ƙarfi (ƙyallen shiga) tare da ƙaramar yarda za a iya amfani da shi don zobe ɗauke da tsayayyen nauyi.

Lokacin ɗaukar kaya yana da girma ko ɗaukar vibration da tasirin tasiri, dole ne a ƙara tsangwamarsa. Lokacin da aka yi amfani da ɓoyayyen ɓarauniya, akwatin ɗaukar nauyi na bakin ciki ko gami mai haske ko akwatin ɗaukar roba, dole ne a ƙara tsangwama.

Lokacin da ake buƙatar juyawa mai girma, dole ne a yi amfani da madaidaiciyar haɗakar ɗaukar nauyi, kuma za a inganta madaidaitan ƙwanƙolin ƙira da rami mai ɗaukar akwatin don kauce wa tsangwama mai yawa. Idan katsalandan yayi yawa, za'a iya shafan geometry na zoben zoben ta hanyar daidaiton yanayin yanayin shaft ko akwatin ɗauka, saboda haka yana lalata daidaito na juyawar.

Idan zobba na ciki da na waje wadanda ba masu rarrabuwa ba (kamar su zurfin tsaga mai tsalle) suna yin aiki a tsaye, zai zama ba shi da matukar wahala a girka kuma a kwance abubuwan. Zai fi kyau a yi amfani da dacewa mai ƙarfi a gefe ɗaya na zoben ciki da na waje.

1) Tasirin kayan kayyaki

Za'a iya raba nauyin ɗaukar zuwa cikin zoben juyawa na ciki, nauyin juyawar waje da nauyin mara kwatance gwargwadon yanayinta. Alaka tsakanin ɗaukar kaya da dacewa na iya koma zuwa daidaitaccen daidaitaccen daidaito.

2) Tasirin girman kaya

Arkashin aikin ɗaukar radial, an matse radius na zobe na ciki an faɗaɗa shi, kuma da'irar tana daƙarin ƙaruwa kaɗan, don haka za a rage tsangwama na farko. Za'a iya lasafta rage tsangwama ta hanyar mai zuwa:

nan:

⊿ DF: rage tsangwama na zobe na ciki, mm

d: aringauke da diamita na ciki, mm

B: Faɗin zoben ciki na ciki, mm

Fr: radial load, n {KGF}

Co: matsakaiciyar darajar nauyi, n {KGF}

Sabili da haka, lokacin da nauyin radial ya kasance mai nauyi (fiye da 25% na ƙimar CO), daidaitawa dole ne ya fi na na haske nauyi.

Game da tasirin tasiri, dacewa dole ne ya zama mai ƙarfi.

3) Tasirin yanayin ƙarancin yanayi

Idan anyi la'akari da gurɓataccen filastik na fuskar dusar kankara, ingancin tsangwama yana shafar ingancin aikin injin saman, wanda za'a iya bayyana shi ta hanyar mai zuwa:

[nika shaft]

⊿deff = (d / (d + 2)) * ......d ...... (3)

[juya shaft]

⊿deff = (d / (d + 3)) * ......d ...... (4)

nan:

Deff: tsangwama mai tasiri, mm

D: tsangwama a bayyane, mm

d: aringauke da diamita na ciki, mm

4) Tasirin yanayin zafi

Gabaɗaya magana, yawan zafin jiki mai ɗauka ya fi zafin jiki kewaye yayin juyawa mai motsi, kuma zafin zoben ciki ya fi zafin jiki shaft lokacin da ɗaukar kewaya tare da kaya, don haka tasirin tsangwama zai ragu ta fadadawar zafi.

Idan bambancin zafin jiki tsakanin yanayin ciki da kwasfa na waje ⊿ T ne, ana iya ɗauka cewa bambancin zafin tsakanin zoben ciki da kuma shaft a farfajiyar saduwa ya kai kimanin (0.01-0.15) ⊿ t. Sabili da haka, ana iya lasafta tsangwama ⊿ DT wanda ya haifar da bambancin zafin jiki ta hanyar dabara 5

⊿dt = (0.10 zuwa 0.15) *t * α * d

≒ 0.0015⊿t * d * 0.01 ...... (5)

nan:

DT: rage tsangwama da ya haifar da bambancin zafin jiki, mm

T: banbancin zafin jiki tsakanin cikin kayan ɗaukar ciki da kewaye da harsashi, ℃

α: lineirgar haɓakar haɓakar linzamin ƙarfe shine (12.5 × 10-6) 1 / ℃

d: aringauke da diamita na ciki, mm

Sabili da haka, lokacin da zafin jiki mai ɗaukar nauyi ya fi ƙarfin zafin jiki na ɗaukar nauyi, dacewa dole ne ya zama m.

Bugu da kari, saboda banbancin bambancin zafin jiki ko coefficient na mikakke fadada tsakanin zoben waje da bawon waje, wani lokacin tsangwama zai karu. Sabili da haka, ya kamata a mai da hankali ga yin amfani da zamiya tsakanin zoben waje da farfajiyar haɗin gidan don kaucewa haɓakar zafin jikin shaft.

5) Matsakaicin matsakaicin ciki na ɗaukar hali wanda ya haifar da dacewa

Lokacin da aka shigar da ɗaukar hoto tare da dacewar tsangwama, zobe zai fadada ko raguwa, don haka ya haifar da damuwa.

Lokacin da damuwa ta yi yawa, wani lokacin zobe zai karye, wanda ke buƙatar kulawa.

Matsakaicin matsin lamba na ciki wanda aka samar ta hanyar daidaitawa za a iya lissafa shi ta hanyar dabara a Tebur 2. A matsayin darajar tunani, matsakaicin tsangwama bai wuce 1/1000 na ƙwanƙolin shaft ba, ko matsakaicin stress da aka samo daga lissafin lissafi a Tebur na 2 bai fi 120MPa {12kgf / mm2} ba.

Matsakaicin matsakaicin ciki na ɗaukar hali wanda ya haifar da dacewa

nan:

: stressarfin damuwa, MPA {kgf / mm2}

d: aringauke da diamita na ciki (ƙirar diamita), mm

Di: diamita mai zagaye ta tsere mai tsayi, mm

Kwallan Ball Di = 0.2 (D + 4d)

Diler mai ɗaukar hoto Di = 0.25 (D + 3d)

Deff: tsangwama mai tasiri na zobe na ciki, mm

Yi: radius na ramin rami, mm

De: tsaran tseren tsere na waje, mm

Kwallan Ball De = 0.2 (4D + d)

Gilashin ɗaukar hoto De = 0.25 (3D + d)

D: aringauke da diamita na waje (diamita bawo), mm

Deff: tsangwama mai tasiri na zobe na waje, mm

DH: diamita na waje na harsashi, mm

E: Yanayin roba shine 2.08 × 105Mpa {21200kgf /


Post lokaci: Dec-18-2020