軸承在設備中的應用相當廣泛,軸承壽命極其關鍵。據統計,旋轉機械的故障中軸承的損壞故障約占30%,而這些根源很簡單,例如貨物列車脫軌事故,據調查發現軸箱中的一個軸承過熱(如圖1),導致車軸斷裂,造成車廂傾覆、交通中斷數小時,事故損失巨大。
軸承故障損傷根源分析:
軸zhou承cheng是shi大da部bu分fen設she備bei的de核he心xin部bu件jian,一yi旦dan軸zhou承cheng失shi效xiao,設she備bei就jiu會hui停ting止zhi,找zhao到dao根gen源yuan以yi避bi免mian事shi故gu再zai次ci發fa生sheng就jiu顯xian得de尤you為wei重zhong要yao。實shi際ji上shang,軸zhou承cheng一yi旦dan受shou損sun,它ta就jiu會hui逐zhu漸jian惡e化hua直zhi到dao無wu法fa工gong作zuo,那na時shi故gu障zhang發fa生sheng的de所suo有you證zheng據ju可ke能neng都dou被bei破po壞huai了le。
如圖2 揭示了損傷從小到大的整個過程,外部顆粒(汙染物)進入軸承,運動中產生凹痕(汙染物被壓入滾道)。凹ao痕hen邊bian緣yuan會hui升sheng高gao,所suo以yi凹ao痕hen看kan起qi來lai像xiang個ge坑keng。滾gun道dao局ju部bu幾ji何he形xing狀zhuang發fa生sheng改gai變bian,使shi得de這zhe個ge區qu域yu無wu法fa形xing成cheng良liang好hao油you膜mo把ba接jie觸chu表biao麵mian分fen離li開kai來lai,結jie果guo造zao成cheng材cai料liao疲pi勞lao。更geng初chu是shi表biao麵mian出chu現xian裂lie縫feng,更geng後hou是shi受shou損sun區qu域yu剝bo落luo,隨sui著zhe繼ji續xu運yun轉zhuan,剝bo落luo不bu斷duan加jia劇ju。到dao後hou來lai,受shou損sun區qu域yu變bian得de如ru此ci之zhi大da,更geng初chu的de受shou損sun點dian(即凹痕)完全消失。此時對受損軸承進行檢查,已很難發現問題的根源:即可能由於密封不好致使汙染物進入軸承。
每種故障都有其特有的特性,通過觀察損傷狀況有可能確定故障根源。下麵中華軸承網(簡稱:華軸網)分享相關軸承損傷類型和軸承損傷的根源
1、磨損
磨損是滾動軸承更常見的故障之一,通常是由異物引起研磨損傷、擦傷、槽痕、圓周線痕或碎屑汙染,分磨耗磨損和粘滯磨損兩大類。
磨mo耗hao磨mo損sun是shi由you於yu軸zhou承cheng內nei部bu有you微wei小xiao異yi物wu,它ta們men可ke能neng是shi來lai自zi外wai部bu或huo內nei部bu的de汙wu染ran顆ke粒li,比bi如ru齒chi輪lun帶dai來lai的de金jin屬shu微wei粒li或huo碳tan化hua物wu。這zhe些xie顆ke粒li將jiang磨mo損sun或huo研yan磨mo滾gun道dao和he滾gun動dong體ti,在zai圓yuan錐zhui滾gun子zi軸zhou承cheng中zhong,滾gun子zi端duan麵mian和he內nei圈quan擋dang邊bian的de磨mo損sun程cheng度du遠yuan比bi滾gun道dao嚴yan重zhong,這zhe種zhong磨mo損sun將jiang造zao成cheng軸zhou向xiang遊you隙xi或huo內nei部bu間jian隙xi擴kuo大da,進jin而er降jiang低di軸zhou承cheng壽shou命ming,導dao致zhi軸zhou承cheng偏pian心xin。此ci外wai,磨mo損sun也ye會hui影ying響xiang軸zhou承cheng所suo在zai機ji器qi的de其qi他ta零ling件jian。汙wu染ran物wu能neng進jin入ru軸zhou承cheng內nei部bu,通tong常chang是shi密mi封feng圈quan嚴yan重zhong磨mo損sun或huo失shi效xiao(或沒有)。潤滑劑分析可能會發現汙染物的來源,從而有助於找到解決問題的方法。
粘滯磨損主要發生在輕負荷、潤滑不良、滾gun動dong體ti速su度du差cha較jiao大da從cong而er產chan生sheng滑hua動dong的de接jie觸chu表biao麵mian。例li如ru,滾gun動dong體ti從cong無wu載zai區qu進jin入ru承cheng載zai區qu的de過guo程cheng,滾gun動dong體ti在zai無wu載zai區qu失shi速su,當dang重zhong新xin進jin入ru承cheng載zai區qu時shi獲huo得de加jia速su。這zhe將jiang導dao致zhi潤run滑hua膜mo撕si破po、滑動、發(fa)熱(re),導(dao)致(zhi)材(cai)料(liao)可(ke)能(neng)從(cong)滾(gun)動(dong)體(ti)轉(zhuan)移(yi)到(dao)滾(gun)道(dao)或(huo)從(cong)滾(gun)道(dao)轉(zhuan)移(yi)到(dao)滾(gun)動(dong)體(ti)上(shang)。早(zao)期(qi)階(jie)段(duan),外(wai)觀(guan)是(shi)發(fa)光(guang)表(biao)麵(mian),但(dan)很(hen)快(kuai)它(ta)就(jiu)變(bian)成(cheng)無(wu)光(guang)表(biao)麵(mian),或(huo)多(duo)或(huo)少(shao)帶(dai)有(you)粘(zhan)上(shang)的(de)材(cai)料(liao)。
2、疲勞
疲勞的表現形式是剝落,即軸承材料出現麻點或脫落,剝落更初發生在滾道或滾動體上。
laizigundaobiaomianxiadepilaoshicailiaoehua,shiyougundaobiaomianxiafangdejiaobianyingliyinqi,gengzhongdaozhicailiaoshuaibian。gengchushichuxianliefeng,liefengsuizhouchenggongzuomanmanfazhan,dangliefengfazhandaobiaomianshi,jiufashengboluo。
來lai自zi表biao麵mian的de疲pi勞lao通tong常chang由you潤run滑hua不bu足zu引yin起qi。潤run滑hua劑ji的de作zuo用yong是shi建jian立li油you膜mo,把ba滾gun道dao與yu滾gun動dong體ti分fen隔ge開kai來lai。當dang潤run滑hua不bu良liang時shi,會hui發fa生sheng金jin屬shu與yu金jin屬shu的de接jie觸chu。表biao麵mian凸tu凹ao不bu平ping(突出部分)xianghujianqie,daozhibiaomianchuxianjianqieyingli。youyucailiaopilao,chuxianxiaoliefeng,ranhoushiweiboluo。gengchuyouyubiaomiancucaodujiangdile,suoyibiaomiankenenghenmingliangguanghua,danshiruguochixufazhanxiaqu,biaomianjiuhuibiandewuguang,biaomianposuihuiyuelaiyueduo,chuxianmadian。
3、機械腐蝕
浸jin蝕shi通tong常chang是shi由you於yu軸zhou承cheng座zuo內nei溫wen度du變bian化hua,內nei部bu空kong氣qi冷leng凝ning,水shui份fen不bu斷duan積ji聚ju而er成cheng。而er濕shi氣qi或huo水shui時shi常chang從cong破po損sun或huo不bu適shi當dang的de密mi封feng圈quan進jin入ru軸zhou承cheng,由you於yu軸zhou承cheng滾gun道dao和he滾gun動dong體ti表biao麵mian精jing度du極ji高gao,極ji易yi受shou到dao濕shi氣qi與yu水shui的de腐fu蝕shi。相xiang比bi其qi它ta損sun壞huai過guo程cheng,發fa生sheng得de較jiao快kuai,能neng發fa展zhan到dao材cai料liao深shen處chu導dao致zhi軸zhou承cheng嚴yan重zhong損sun傷shang。空kong氣qi濕shi度du過guo高gao或huo用yong手shou指zhi觸chu摸mo滾gun道dao,都dou能neng導dao致zhi這zhe種zhong類lei型xing的de腐fu蝕shi。因yin此ci做zuo好hao防fang護hu非fei常chang重zhong要yao。潮chao濕shi腐fu蝕shi通tong常chang發fa生sheng在zai靜jing止zhi狀zhuang態tai,處chu於yu深shen處chu的de鏽xiu會hui導dao致zhi軸zhou承cheng早zao期qi損sun壞huai。
摩(mo)擦(ca)腐(fu)蝕(shi)的(de)根(gen)源(yuan)是(shi)兩(liang)個(ge)承(cheng)載(zai)麵(mian)之(zhi)間(jian)的(de)微(wei)移(yi)動(dong)。大(da)多(duo)數(shu)情(qing)況(kuang)下(xia),這(zhe)種(zhong)摩(mo)擦(ca)腐(fu)蝕(shi)發(fa)生(sheng)在(zai)軸(zhou)承(cheng)外(wai)徑(jing)和(he)軸(zhou)承(cheng)座(zuo)之(zhi)間(jian)和(he)軸(zhou)承(cheng)孔(kong)和(he)軸(zhou)之(zhi)間(jian),微(wei)移(yi)動(dong)主(zhu)要(yao)由(you)滾(gun)動(dong)體(ti)經(jing)過(guo)時(shi)產(chan)生(sheng)的(de)循(xun)環(huan)負(fu)荷(he)引(yin)起(qi)。配(pei)合(he)不(bu)好(hao)、軸zhou彎wan曲qu或huo接jie觸chu麵mian有you缺que陷xian,都dou能neng導dao致zhi或huo加jia速su摩mo擦ca腐fu蝕shi的de發fa生sheng。空kong氣qi能neng進jin入ru沒mei有you保bao護hu的de表biao麵mian,加jia速su腐fu蝕shi的de發fa展zhan。形xing成cheng的de氧yang化hua鐵tie,體ti積ji要yao比bi純chun鋼gang大da得de多duo,造zao成cheng材cai料liao變bian大da,應ying力li升sheng高gao,甚shen至zhi對dui軸zhou承cheng滾gun道dao也ye是shi這zhe樣yang,從cong而er導dao致zhi過guo早zao性xing的de表biao麵mian下xia疲pi勞lao。摩mo擦ca腐fu蝕shi容rong易yi造zao成cheng軸zhou承cheng圈quan開kai裂lie。
假(jia)硬(ying)化(hua)也(ye)是(shi)一(yi)種(zhong)摩(mo)擦(ca)腐(fu)蝕(shi),發(fa)生(sheng)在(zai)滾(gun)動(dong)體(ti)和(he)滾(gun)道(dao)間(jian)的(de)接(jie)觸(chu)區(qu)域(yu),是(shi)循(xun)環(huan)振(zhen)動(dong)引(yin)起(qi)的(de)塑(su)性(xing)接(jie)觸(chu)麵(mian)微(wei)移(yi)動(dong)和(he)回(hui)彈(dan)所(suo)致(zhi)。由(you)於(yu)它(ta)是(shi)發(fa)生(sheng)在(zai)軸(zhou)承(cheng)靜(jing)止(zhi)和(he)承(cheng)載(zai)時(shi),所(suo)以(yi)損(sun)傷(shang)出(chu)現(xian)在(zai)滾(gun)動(dong)體(ti)節(jie)圓(yuan)處(chu)。根(gen)據(ju)振(zhen)動(dong)的(de)強(qiang)度(du)、潤滑條件和負荷,腐蝕和磨損可能同時發生,在滾道上形成淺凹陷。通常,振動會導致潤滑劑的局部缺失、金(jin)屬(shu)與(yu)金(jin)屬(shu)接(jie)觸(chu)和(he)磨(mo)耗(hao)磨(mo)損(sun)。凹(ao)陷(xian)處(chu)外(wai)觀(guan)通(tong)常(chang)變(bian)得(de)無(wu)光(guang),經(jing)常(chang)褪(tui)色(se),有(you)時(shi)因(yin)為(wei)發(fa)生(sheng)潮(chao)濕(shi)腐(fu)蝕(shi)而(er)略(lve)帶(dai)紅(hong)色(se)。偶(ou)爾(er)凹(ao)陷(xian)處(chu)呈(cheng)現(xian)光(guang)亮(liang)表(biao)麵(mian),可(ke)能(neng)主(zhu)要(yao)是(shi)因(yin)為(wei)仍(reng)有(you)潤(run)滑(hua)劑(ji),還(hai)沒(mei)有(you)發(fa)生(sheng)磨(mo)耗(hao)磨(mo)損(sun)。假(jia)硬(ying)化(hua)損(sun)壞(huai)能(neng)導(dao)致(zhi)球(qiu)軸(zhou)承(cheng)的(de)球(qiu)麵(mian)出(chu)現(xian)空(kong)洞(dong),滾(gun)子(zi)軸(zhou)承(cheng)出(chu)現(xian)線(xian)條(tiao)。
4、電腐蝕
當電流通過軸承時,將會通過滾動體在內、外圈間傳導,可能出現過高電壓造成的損傷。接觸表麵發生的過程與電弧焊(小接觸麵上的高密度電流)類似,材料被加熱到回火至融化等不同程度。在材料被回火、再硬化或融化的地方,外觀出現大小不一的褪色區。在材料融化的地方,形成大約0.1mm 至 0.5mm 的坑。
同tong樣yang,電dian流liu泄xie漏lou也ye能neng造zao成cheng損sun傷shang,電dian流liu泄xie漏lou來lai自zi通tong過guo軸zhou承cheng的de雜za散san電dian流liu,而er雜za散san電dian流liu通tong常chang是shi由you頻pin率lv變bian化hua引yin起qi的de。主zhu要yao的de可ke見jian損sun傷shang是shi凹ao槽cao,形xing似si洗xi衣yi板ban圖tu案an。這zhe些xie凹ao槽cao的de形xing狀zhuang,在zai球qiu軸zhou承cheng呈cheng接jie觸chu橢tuo圓yuan,在zai滾gun子zi軸zhou承cheng呈cheng接jie觸chu線xian,滾gun動dong體ti通tong常chang出chu現xian均jun勻yun的de褪tui色se。相xiang比bi過guo高gao電dian壓ya損sun傷shang,在zai電dian流liu泄xie漏lou中zhong,電dian流liu通tong過guo的de區qu域yu更geng大da,結jie果guo電dian流liu密mi度du變bian小xiao,損sun傷shang溫wen度du也ye較jiao低di。因yin此ci主zhu要yao的de可ke見jian損sun壞huai是shi回hui火huo效xiao應ying,即ji軸zhou承cheng表biao麵mian變bian軟ruan。當dang用yong高gao倍bei放fang大da鏡jing觀guan察cha損sun傷shang部bu位wei,通tong常chang也ye能neng看kan到dao坑keng。
5、塑性變形
靜jing態tai負fu荷he或huo衝chong擊ji負fu荷he可ke產chan生sheng過guo載zai,從cong而er導dao致zhi塑su性xing變bian形xing,在zai滾gun道dao上shang形xing成cheng凹ao痕hen。通tong常chang安an裝zhuang不bu當dang是shi產chan生sheng此ci問wen題ti的de根gen源yuan,即ji在zai軸zhou承cheng圈quan上shang用yong力li不bu當dang,從cong而er在zai滾gun動dong體ti上shang產chan生sheng衝chong擊ji負fu荷he。碎sui屑xie造zao成cheng的de凹ao痕hen是shi因yin為wei外wai部bu顆ke粒li(汙染物)進jin入ru軸zhou承cheng,被bei滾gun動dong體ti壓ya入ru滾gun道dao。凹ao痕hen的de大da小xiao和he形xing狀zhuang取qu決jue於yu顆ke粒li的de性xing質zhi。凹ao痕hen處chu滾gun道dao的de幾ji何he形xing狀zhuang被bei破po壞huai,潤run滑hua受shou到dao影ying響xiang。表biao麵mian出chu現xian應ying力li,疲pi勞lao導dao致zhi表biao麵mian過guo早zao剝bo落luo。
搬ban運yun造zao成cheng的de凹ao陷xian是shi由you於yu軸zhou承cheng表biao麵mian被bei硬ying的de尖jian銳rui物wu體ti碰peng壞huai。由you於yu軸zhou承cheng表biao麵mian精jing度du極ji高gao,當dang局ju部bu過guo載zai,比bi如ru軸zhou承cheng掉diao落luo地di上shang,就jiu可ke能neng會hui在zai表biao麵mian磕ke出chu凹ao痕hen,從cong而er讓rang軸zhou承cheng無wu法fa工gong作zuo。
6、破裂和開裂
受壓破裂是因為局部過載或應力過高,造成應力集中超過了材料的抗拉強度所致。常見是野蠻拆裝軸承 (衝擊)huoyuanzhuizuohuochentaoningdetaijin。dangyonglangtouheyingzaozhijieqiaodazhouchengquan,kenengdaozhixingchengweixiaodeliefeng。dangzhouchengtourushiyongshi,zhouchengquankenengyouxiaopiantuoluo。eranzhuangshiyuanzhuizuohuochentaoningdetaijin,jieguozhouchengquanchuxiankanglayingli(圓周應力),當軸承投入使用時產生裂縫。
pilaopoliekaishiyuwanquzhuangtaixiayinglichaoguopilaoqiangdushi。gengchuchuxianyitiaoliefeng,ranhoubuduanzengduo,genghouzhenggezhouchengquanhuobaochijiakailie。dangshiyongjinpeiheshikenengchuxianpilaopolie,yinweijinpeihekenengchanshenghengaodeyuanzhouyingli。ranhoujiaobianyingliheyuanzhouyingligongtongzuoyong,zaochengzhouchengquandeguozaopilao,zhenggequanliekai。
熱開裂產生於兩個表麵相互嚴重摩擦時,產生的摩擦熱導致裂縫,通常與滑動方向成直角。
很hen多duo軸zhou承cheng故gu障zhang都dou可ke以yi避bi免mian。深shen入ru的de軸zhou承cheng損sun傷shang根gen源yuan分fen析xi可ke以yi找zhao到dao問wen題ti根gen源yuan,通tong過guo采cai取qu適shi當dang的de措cuo施shi,能neng提ti前qian避bi免mian故gu障zhang再zai次ci發fa生sheng,降jiang低di故gu障zhang成cheng本ben。