Vim li cas Engineers xaiv Sintered Bearings: Cov hmoov Metallurgy Advantage

Kev Tshawb Fawb Tom Qab Sintered Bronze Bearings

 

Kev tsim kev tshawb fawb tom qab sintered bronze bearings yog nyob ntawm kev tswj xyuas cov khoom siv hlau uas ua rau cov hlau xoob xoob mus rau hauv cov khoom ua haujlwm nrog kev tsim cov porosity. Cov txheej txheem zoo kawg no pib nrog cov khoom siv raw thiab xaus nrog cov khoom sib xyaw uas muab lubrication zoo ib yam thoob plaws hauv nws lub neej ua haujlwm.

 

Hmoov metallurgy: Hloov Hlau rau hmoov thiab rov qab

Hmoov metallurgy ua lub hauv paus ntawm sintered bearing ntau lawm, pib nrog hlau hmoov tsim. Cov neeg tsim khoom siv atomized bronze hmoov uas muaj tooj liab nrog 9-11% tin. Cov hmoov tau muab sib xyaw nrog cov khoom ntxiv, suav nrog cov roj nplaum uas pab nrog cov txheej txheem compaction. Cov sib tov ces mus los ntawm txhua yam compaction nyob rau hauv tuag presses ntawm pressures li ntawm 200 mus rau 1,500 MPa raws li qhov xav tau kawg ceev.

Qhov "ntsuab" txav mus rau txheej txheem sintering tom qab compaction. Lub voj voog hluav taws xob no ua kom sov cov khoom mus txog 820 ° C hauv qhov chaw tswj hwm ntawm nitrogen thiab hydrogen (feem ntau hauv qhov piv ntawm 70: 30). Qhov kub nyob qis dua cov hlau melting point tab sis mus txog siab txaus ua rau muaj zog-state diffusion. Cov hlau hais fuse ua ke ntawm cov ntsiab lus sib txuas thaum lub sijhawm tseem ceeb no thiab tsim kom muaj ib qho khoom tsis tau ntxeem tau uas ua rau nws qhov ruaj khov.

 

Microstructure ntawm Sintered Materials: Porosity los ntawm Tsim

Sintered bronze bearings feature txhob txwm porosity uas ua haujlwm rau lub hom phiaj, tsis zoo li cov khoom hlau. Cov kabmob no feem ntau muaj qhov porosity ntawm 15% thiab 25% los ntawm ntim. Qhov no feature teev cov ntaub ntawv sintered sib nrug los ntawm cam khwb cia hlau thiab cuam tshuam rau lawv txhua yam, thermal, thiab functional zog los ntawm ntau.

Cov kabmob lub microstructure muajinterconnected poresuas tsim ib lub network thoob plaws hauv cov khoom. Lub network no tso cai rau cov roj nplua nyeem kom txav mus los hauv cov qauv kev coj tus kheej. Cov yam ntxwv ntawm hmoov, compaction siab, thiab sintering tej yam kev mob txiav txim qhov loj thiab faib ntawm cov pores. Lub porosity nyob twj ywm "qhib" thaum tswj kom zoo, uas txhais tau hais tias cov pores txuas es tsis muaj nyob raws li cov voids cais.

Lub porosity txo cov neeg kho tshuab lub zog piv rau cov khoom hlau tab sis ua rau cov bearings muaj txiaj ntsig los ntawm kev ua kom nws tus kheej lubrication.^[2]. Cov kws tshaj lij tuaj yeem kho qhov porosity feem pua ​​raws li qhov xav tau ntawm daim ntawv thov, nrhiav qhov sib npaug ntawm lub zog thiab cov kev xav tau lubrication.

 

Roj Impregnation Txheej Txheem: Tsim Tus Kheej Lubrication

Cov ntxeem tau bronze bearing mus los ntawm cov roj impregnation tom qab sintering. Cov txheej txheem tseem ceeb no hloov nws mus rau hauv tus kheej-lubricating tivthaiv. Cov kabmob nkag mus rau hauv lub tshuab nqus tsev qhov chaw uas huab cua tawm hauv qhov hws ua ntej immersion hauv cov roj tshwj xeeb. Cov roj sau tsawg kawg yog 90% ntawm cov pore ntim los ntawm kev ua haujlwm capillary.

Cov kabmob ua haujlwm los ntawm lub tshuab lubrication tshwj xeeb thaum lub sijhawm ua haujlwm. Lub tshav kub los ntawm kev sib hloov ntawm ncej tiv thaiv cov kabmob nto ua rau cov roj ntws tawm ntawm lub qhov hws mus rau cov kabmob-shaft interface. Qhov no tsim ib zaj duab xis nyias nyias ntawm cov khoom txav. Cov roj rov qab mus rau hauv qhov pores los ntawm kev ua haujlwm capillary thaum cov kabmob txias thaum lub sijhawm tsis ua haujlwm, tswj xyuas lub voj voog txuas ntxiv.^[2].

Cov roj ncig tsim dab tsi engineers hu ua "tswj kev ua haujlwm". Loaded aav tso roj thaum lub sij hawm ua hauj lwm thaum unloaded cheeb tsam absorbed rov qab. Qhov no tsim ib lub tshuab lubrication perpetual uas ua haujlwm yam tsis muaj kev saib xyuas. Cov kabmob ntawm tus kheej no tuaj yeem ua haujlwm tau zoo rau 3,000-5,000 xuab moos yam tsis xav tau lubrication ntxiv.

 

Cov Khoom Siv Khoom Uas Txhim Kho Kev Ua Haujlwm

Sintered bearings tau txais lawv cov kev ua tau zoo heev los ntawm cov khoom siv tshwj xeeb uas tuaj ntawm covhmoov metallurgy txheej txheem ntau lawm. Cov khoom no muab cov khoom sintered loj zoo dua li niaj zaus cam khwb cia lossis machined Cheebtsam hauv ntau yam kev siv.

 

Uniform Strength Distribution vs. Cast Materials

Cov txheej txheem hmoov metallurgy tsim cov txheej txheem zoo dua li cov txheej txheem casting. Castings feem ntau muaj teeb meem vim molten alloy ntsiab tsis txias sib npaug. Qhov no ua rau muaj qhov sib txawv ntawm lub zog, qhov ntom ntom, thiab thermal zog thoob plaws hauv cov khoom. Cov khoom kawg kuj tuaj yeem kis kab mob thaum cov hlau molten reacts nrog cov ntaub ntawv peev thaum casting.

Sintered Cheebtsam yog txawv. Lawv muaj qhov sib xyaw ua ke ntawm txhua theem tsim khoom. Cov hmoov hlau hmoov kis tusyees ua ntej compaction thiab nyob rau hauv qhov chaw thaum sintering. Qhov no tsim kom muaj qhov sib xws microstructure uas muaj zog dua, nyuaj dua, thiab tiv taus ntau dua los hnav thoob plaws tag nrho.

Cov txheej txheem sintering muab kev tswj xyuas zoo dua ntawm cov khoom siv microstructure dua li forging lossis casting. Kev tshawb fawb tau pom tias cov khoom ua tau zoo sintered tuaj yeem ua tau 2-10 npaug zog dua li cov hlau cam. Lub zog yuav qis dua vim qhov porosity, tab sis nws kis tau tusyees thoob plaws ib feem. Qhov no ua rau kev ua haujlwm nyob rau hauv load ntau dua kwv yees.

 

Dimensional Stability nyob rau hauv kub hloov pauv

Sintered bearings yeej ci thaum nws los ua kom lawv cov duab ntawm qhov sib txawv kub. Cov khoom no ua kom nruj me ntsis kam rau ua nrog tsawg distortion ua tsaug rau lawv txoj kev tsim khoom tshwj xeeb.

Ob yam tseem ceeb tsim qhov kev ruaj ntseg no. Cov pores muab qhov chaw rau me ntsis thermal expansion yam tsis hloov tag nrho qhov ntev. Cov txheej txheem microstructure tseem nthuav dav thiab sib cog lus sib npaug ntau dua li cov ntaub ntawv pov tseg, uas tiv thaiv kev sib tsoo thiab kev ntxhov siab.

Qhov kev ruaj ntseg no pab ntau heev thaum kub hloov thaum siv. Cov qauv txhuas oxide txo qis los ntawm 17.6% thaum lub sij hawm sintering ntawm 1600 ° C tab sis tseem khaws 98.3% txheeb ze ntom ntom nrog qhov zoo sib xws. Cov khoom siv hlau nyob ruaj khov txawm tias thaum sintered saum 2500 ° F (1370 ° C).

Zoo dua qhov qhov tseeb yog los ntawm kev tswj cov tshuaj ntxiv. Silicon nitride ntxiv rau cov qauv hloov kho boron pab tiv thaiv kev cuam tshuam ntau dhau thaum sintering.

 

Hnav Resistance yam ntxwv ntawm Common Alloys

Koj tuaj yeem tau txais sintered bearings nyob rau hauv sib txawv alloy sib tov, txhua tus nrog nws tus kheej hnav-tiv taus nta:

Bronze-raws li Alloys: Tsis tu ncuasintered tooj liab(90% tooj liab, 10% tin) tiv taus hnav zoo thiab kav ntev, ua rau nws yog qhov kev xaiv zoo tshaj plaws rau kev siv feem ntau. Ntxiv graphite rau tooj liab-based composites pab lawv ua haujlwm zoo dua nrog kev sib txhuam tsawg thiab nyob ruaj khov ntawm ntau qhov kub thiab txias.

Leaded Bronze: Cov alloys no muaj 14-16% txhuas thiab li ntawm 20% tsawg tin dua li tus qauv 90-10 bronze. Lawv tsim kev sib txhuam tsawg dua thiab tiv thaiv galling zoo dua thaum lubricant khiav qis. Kev sim ua pov thawj tias cov ntaub ntawv no tuaj yeem siv sijhawm ntev dua 7-10 npaug ntawm cov hlau dov hauv qee qhov xwm txheej (Pv = 6-12 MPa·m / sec).

Copper-Iron Combinations: Cov alloys pauv ceev txwv kom zoo dua compressive zog. Lawv ua haujlwm zoo rau kev poob siab thiab hnyav hnyav. Ntxiv 1.5% cov pa roj carbon monoxide pub rau cov ntaub ntawv no tau txais kev kho cua sov kom ncav cuag Rockwell C65 hardness, ua rau lawv cuam tshuam-resistant.

Hlau-Based Alloys: Cov nqi no tsawg dua tab sis tseem ua cov bearings zoo, uas ua rau lawv nrov hauv tsheb. Lawv tuav cov roj ntau dua vim qhov porosity ntau dua thiab tiv taus hnav zoo, txawm tias lawv muaj qis dua PV txwv.

Lub sintering kub plays lub luag haujlwm tseem ceeb hauv kev hnav. Ultra High-Temperature Sintering (UHTS) saum toj no 2500 ° F (1370 ° C) tsim me me, nthuav tawm pores thoob plaws hauv cov khoom. Qhov no ua rau qhov chaw muaj zog, tawv dua, thiab tiv taus hnav dua li cov txheej txheem sintering li niaj zaus.

 

Self-Lubricating Sintered Bearings: Lawv Ua Haujlwm Li Cas

 

Self-lubricating sintered bearings ua hauj lwm los ntawm ib tug zoo kawg nkaus kaw-voj lubrication system uas khiav tsis muaj kev pab sab nraud. Cov khoom no saib xyuas lawv tus kheej lubrication los ntawm cov txheej txheem tshwj xeeb uas hloov mus rau kev ua haujlwm.

 

Capillary Action Mechanism

Lub hwj chim ntawm tus kheej-lubricating sintered bearings los ntawm lawv cov kev sib txuas cov qauv ntxeem tau, uas muaj 10% mus rau 35% ntawm tag nrho cov kabmob ntim. Cov pores no tsim ib qho kev sib txuas sib txuas thoob plaws hauv cov khoom siv thiab ua haujlwm raws li cov roj reservoirs. Thawj qhov ntim ntawm cov voids no tshwm sim los ntawm lub tshuab nqus tsev impregnation, qhov twg huab cua tawm hauv qhov hws ua ntej cov roj nkag mus. Cov phab ntsa ntxeem tau ces rub thiab tuav cov roj los ntawm lub zog capillary - tib yam txheej txheem uas ua rau cov kua nce siab tiv thaiv lub ntiajteb txawj nqus hauv qhov chaw nruj.

Qhov no capillary feature tsim dab tsi engineers hu ua "khiav-hauv" saum npoo ntawm zawv zawg txheej. Koj yuav pom kev sib txhuam qis txawm tias ua ntej cov kabmob hits nws qhov chaw qab zib. Lub microstructure ua zoo li daim txhuam cev uas khaws thiab tso cov roj nplua nyeem raws li xav tau thoob plaws hauv nws lub neej.

 

Roj tso tawm thaum ua haujlwm

Cov kabmob tso tawm cov roj rau ntawm nws qhov chaw los ntawm ntau lub tshuab thaum nws pib khiav. Thaum tshav kub kub los ntawm kev sib txhuam ntawm cov ncej thiab cov kabmob ua rau cov roj nthuav dav. Qhov kev nthuav dav no thawb qee cov roj tawm ntawm lub qhov hws mus rau qhov chaw zawv zawg.

Kev sib hloov ntawm ncej tsim ib qho "tswj kev ua haujlwm" tib lub sijhawm. Qhov kev txiav txim no ua rau cov cheeb tsam tsis zoo nyob rau hauv cov roj lubricating zaj duab xis thiab rub ntau cov roj los ntawm cov kabmob lub cev mus rau saum npoo. Ua ke, cov nyhuv ntawm cov twj tso kua mis thiab thermal expansion tsim cov roj tiv thaiv zaj duab xis ntawm cov ncej thiab cov kabmob tiv thaiv kev sib cuag ntawm cov hlau-rau-hlau.

Cov kabmob xav tau kev sib hloov ua haujlwm kom zoo. Koj xav tau kev kub ceev thiab kev sib hloov tas mus li kom ua tiav cov yeeb yaj kiab lubricating ntawm cov kabmob nto.

 

Reabsorption Thaum lub caij txias

Lub voj voog tus kheej lubricating txuas ntxiv thaum kev sib hloov nres thiab cov kabmob txias. Cov roj ntau dhau rov qab mus rau cov qauv ntxeem tau los ntawm kev ua haujlwm capillary thaum kub poob. Qhov no reabsorption nres cov roj los ntawm kev tsim los yog poob.

Cov kabmob rub rov qab cov roj uas raug yuam tawm ntawm qhov chaw thauj khoom thaum lub sijhawm ua haujlwm. Qhov kev sib pauv tas li - cov roj tawm thaum lub sijhawm ua haujlwm thiab rov qab mus rau hauv lub sijhawm so - tsim kom muaj lub voj voog lubrication tsis kawg. Cov txheej txheem ua kom cov roj nplua nyeem sib npaug thoob plaws qhov zawv zawg, yog li kev ua haujlwm tseem muaj zog txawm tias cov zawv zawg txheej hnav.

 

Kev ntsuas kev ua tau zoo: PV Factors thiab Load Limits

 

Cov kws ua haujlwm saib xyuas cov kev ntsuas kev ua tau zoo los xaiv cov kabmob sintered uas haum rau kev ua haujlwm sib txawv. Cov kev ntsuas tsis zoo no pab txiav txim siab txog kev txwv kev ua haujlwm nyab xeeb thiab tiv thaiv kev ua tsis tiav thaum ntxov.

 

Nkag siab txog PV Factors hauv Kev Xaiv Bearing

PV yam tseem ceeb ua lub luag haujlwm tseem ceeb hauv kev xaiv cov kabmob sintered. Koj xam nws los ntawm kev muab cov kabmob load (P) hauv phaus ib square inch ntawm qhov projected bearing cheeb tsam los ntawm qhov nrawm nrawm (V) hauv ko taw ib feeb. Qhov no muab peb qhov Performance index ntawm kev sib txhuam kub ntawm cov kabmob uas cuam tshuam ncaj qha rau nws ntev npaum li cas. Standard porous bearings feem ntau muaj qhov siab tshaj plaws PV tus nqi ntawm 50,000. Cov neeg tsim khoom pom zoo kom ua haujlwm tsis tu ncua ntawm 20,000 kom txuas ntxiv lub neej kev pabcuam yam tsis muaj lubrication ntxiv. Thrust bearings xav tau kev ceev faj ntxiv nrog qhov siab tshaj plaws PV ntawm 10,000.

Cov kabmob lub neej ua haujlwm tawm tsam nws tus nqi PV - siab dua PV txhais tau tias lub neej ua haujlwm luv dua. Qhov no yog vim li cas cov engineers feem ntau xaiv qhov qis dua PV qhov tseem ceeb thaum tsim los ua kom cov khoom siv ntev dua.

 

Static vs. Dynamic Load Capacity

Static load tshwm sim thaum bearing nto tsis txav mus rau ib leeg. Cov ntaub ntawv muaj zog dhau los ua qhov tseem ceeb txwv rau hauv cov xwm txheej no. Qhov txwv tsis pub thauj khoom zoo li qub qhia tau hais tias lub zog uas hloov pauv cov kabmob bore txoj kab uas hla los ntawm ib nrab ntawm tag nrho cov kev kam rau siab.

Dynamic load cuam tshuam nrog kev txav uas hnav cov kabmob. Sintered bearings feem ntau muaj dynamic load ratings ntawm ib feem peb ntawm lawv qhov zoo li qub load ntsuam xyuas. Qhov kev txo qis no qhia tau hais tias qhov kev txav mus tas li cuam tshuam li cas rau cov kabmob.

 

Kev txwv ceev ntawm cov khoom sib txawv Sintered

Txhua sintered muaj pes tsawg leeg muaj nws tus kheej ceev txwv. Bronze-based cov ntaub ntawv cia koj khiav ntawm qhov nrawm dua. Hlau-raws li kev sib xyaw ua lag luam qee qhov nrawm kom zoo dua compressive zog. Tus qauv sintered bearings feem ntau khiav ntawm qhov nrawm mus txog 1000 ko taw ib feeb.

 

Temperature Effects ntawm Kev Ua Haujlwm Ciam Teb

Kub kub hloov pauv li cas sintered bearings ua. Feem ntau cov ntxhia-based lubricating roj ua haujlwm zoo tshaj plaws ntawm 0-80 ° C. Kev ua tau zoo poob qis dua 80 ° C, poob mus txog 60% ntawm cov nqi ib txwm muaj.

Kub kuj hloov pauv li cas roj txav hauv cov qauv ntxeem tau. Cov cua sov ua kom cov roj nthuav dav thiab ntws yooj yim los ntawm lub qhov hws mus rau qhov chaw bearing. Cov kub txias ua kom cov roj thicker, uas yuav txwv tsis pub lubrication kom zoo thaum pib.

 

Sib piv Sintered Bearings vs Pob Bearings

 

Cov engineers yuav tsum nkag siab txog qhov sib txawv ntawm cov sintered thiab pob bearings kom ua tiav qhov siab tshaj plaws. Cov kabmob no tuaj nrog lawv tus kheej qhov zoo uas ua rau lawv zoo tagnrho rau qhov chaw ua haujlwm tshwj xeeb.

 

Kev sib txhuam coefficient

Pob bearings thiab sintered bearings qhia cov yam ntxwv sib txawv. Kev sib txhuam coefficients ntawm pob bearings yog qis, xws li 0.0008 txog 0.0035 nyob ntawm seb hom. Sintered bearings muaj kev sib txhuam ntau dua tab sis ua rau nws los ntawm lawvroj-impregnated qauvuas ua rau lawv lubricated. Kev sib txhuam coefficient hauv sintered bearings nce raws li cov roj depletes, uas ua rau lawv xaiv tsis zoo rau kev siv ceev ceev yam tsis muaj lubrication zoo.

Pob bearings yog koj thawj koom ruam zoo tshaj plaws kom txo qis zog vim tias lawv yob es tsis txhob swb zoo li sintered bearings. Tab sis sintered bearings yuav yog qhov kev xaiv zoo dua hauv kev ua haujlwm nres thiab mus. Lawv tus kheej-lubricating nta tiv thaiv cov teeb meem nplaum nplaum uas koj feem ntau pom hauv pob bearings uas tsis zoo lubricated.

 

Lub suab nrov thiab vibration yam ntxwv

Sintered bearings khiav ntsiag to dua li pob bearings, tshwj xeeb tshaj yog nyob rau hauv high speeds. Pob bearings tsim suab nrov vim lawv cov ntsiab lus dov sib cuag. Cov suab nrov yuav nce ntxiv thaum lub pob bearings ncav cuag qhov kawg ntawm lawv lub neej.

Pob bearings xa ntau kev co los ntawm cov tshuab tshuab. Kev tshawb fawb qhia tau hais tias kev vibration ntau dhau tuaj yeem ua rau lub neej luv luv thiab ua rau lawv nrov nrov. Cov zawv zawg txav hauv sintered bearings pab lawv nqus kev co zoo dua. Qhov no ua rau lawv muaj kev xaiv zoo rau cov ntawv thov uas lub suab nrov yuav tsum tau khaws cia.

 

Yuav Tsum Tau Saib Xyuas: Teem caij vs. Kev Kho Tus Kheej

Cov kev tu ncua ntawm cov bearings no txawv heev. Pob bearings xav tau lubrication tsis tu ncua kom khiav tau zoo thiab zam kev ua tsis tiav thaum ntxov. Sintered bearings khaws cov roj hauv lawv cov qauv ntxeem tau, uas tsim kom muaj lub cev lubricating uas xav tau kev saib xyuas me ntsis.

Koj xav tau cov kws tshaj lij los tshawb xyuas cov pob bearings thaum lub sijhawm ua haujlwm. Sintered bearings tseem ua haujlwm txawm tias lawv pib ua tsis tiav. Lawv feem ntau ua suab nrov es tsis txhob txeeb kiag li - tsis zoo li cov pob bearings uas yuav kaw tsis tau ceeb toom.

 

Lifespan nyob rau hauv ntau yam kev ua haujlwm

Pob bearings kav ntev dua nyob rau hauv high-speed thiab high-load tej yam kev mob. Kev ua haujlwm ib puag ncig ua lub luag haujlwm tseem ceeb hauv kev ua haujlwm zoo npaum li cas. Sintered bearings ua tau zoo hauv kev ua haujlwm tsis tu ncua, nruab nrab-ceev. Pob bearings kov pib-nres thiab rov qab ua haujlwm zoo dua.

Kub muaj feem cuam tshuam ntev npaum li cas ob hom kabmob kav ntev. Pob bearings ua haujlwm zoo thoob plaws qhov dav ntawm qhov kub thiab txias, ob qho tib si siab thiab qis. Sintered bearings ua haujlwm zoo tshaj plaws txog li 85 ° C. Tshaj ntawd, lawv poob lawv lub peev xwm los lubricate sai dua.

 

Xaus

Sintered bearings sawv cev rau kev ua tiav hauv engineering uas sib txuas cov hmoov metallurgy nrog nws tus kheej lub peev xwm lubricating. Lawv cov qauv ntxeem tau ua rau 10% mus rau 35% ntawm tag nrho cov ntim thiab tsim kom muaj kev sib txuas ntawm cov kev sib txuas uas ua kom muaj lubrication tsis tu ncua.

Cov kabmob tshiab no tseem nyob ruaj khov ntawm qhov sib txawv ntawm qhov kub thiab txias thiab tswj lub zog sib npaug thoob plaws hauv lawv cov qauv. Thaum lawv cov kev sib txhuam coefficient tshaj cov pob bearings, lawv tus kheej-lubricating qhov ua rau lawv zoo meej rau cov ntawv thov uas xav tau kev tu me me thiab kev ua haujlwm ruaj khov.

Cov txheej txheem tsim khoom cia siab rau qhov tseeb ntawm metallurgical precision thiab tshwj xeeb sintering kub ntawm 800 ° C thiab 850 ° C. Qhov no tsim cov kabmob uas muaj kev ntseeg siab ntawm PV yam txog li 50,000. Standard bronze compositions nrog 90% tooj liab thiab 10% tin muab kev tiv thaiv zoo heev tiv thaiv hnav thiab corrosion. Cov khoom no ua rau lawv muaj txiaj ntsig hauv qhov chaw tsim khoom ntim ntau.

Engineers pom sintered bearings 'cov txiaj ntsig xav tau. Lawv ua haujlwm ntsiag to, xav tau kev saib xyuas me ntsis, thiab ua tau raws li qhov nruab nrab ceev thiab thauj khoom. Ua ke nrog nws tus kheej lubrication, cov yam ntxwv no ua rau lawv xaiv zoo tshaj plaws thaum ua haujlwm zoo ib yam, tsis muaj kev saib xyuas tsis muaj teeb meem ntau dua li qhov siab tshaj plaws lossis lub peev xwm thauj khoom.