加熱爐鼓風機電機由變頻器驅動，在運行過程中遇到負載端軸承加熱的問題。兩臺鼓風機電機在(zai)運行(xing)半年內(nei)(nei)，電(dian)(dian)機負載(zai)端軸(zhou)承(cheng)(cheng)嚴重加熱(re)。軸(zhou)承(cheng)(cheng)內(nei)(nei)的潤滑(hua)脂熔化，軸(zhou)承(cheng)(cheng)在(zai)短時間內(nei)(nei)鎖定，電(dian)(dian)機堵塞跳閘，導(dao)致(zhi)加熱(re)爐停止，對生產產生很(hen)大(da)影響。之(zhi)后，檢查發現軸(zhou)承(cheng)(cheng)箱內(nei)(nei)沒有潤滑(hua)脂，軸(zhou)承(cheng)(cheng)加熱(re)變黑，內(nei)(nei)外有摩擦板條燒(shao)損圖案。根(gen)據這種情(qing)況，我們判(pan)斷軸(zhou)承(cheng)(cheng)電(dian)(dian)流是電(dian)(dian)機負載(zai)端軸(zhou)承(cheng)(cheng)加熱(re)的主要原因。

1　軸承電流的(de)原因和危害

感應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)中始終存在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。在(zai)(zai)(zai)正弦波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的(de)(de)(de)驅動下(xia)，由于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)轉子(zi)(zi)槽尺寸(cun)的(de)(de)(de)偏(pian)差、磁(ci)性材料定向(xiang)性能的(de)(de)(de)變(bian)(bian)化或(huo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)的(de)(de)(de)三相(xiang)不平(ping)衡、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)磁(ci)通(tong)(tong)量的(de)(de)(de)不平(ping)衡，軸電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)產(chan)生(sheng)在(zai)(zai)(zai)轉子(zi)(zi)軸上(shang)。軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)幅(fu)值小，危(wei)害(hai)小。由變(bian)(bian)頻(pin)(pin)(pin)器驅動，由于(yu)原理的(de)(de)(de)不同(tong)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)(de)危(wei)害(hai)大大增(zeng)加。通(tong)(tong)用變(bian)(bian)頻(pin)(pin)(pin)器多(duo)用PWM逆變(bian)(bian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路采用高(gao)頻(pin)(pin)(pin)功率(lv)元件IGBT等(deng)(deng)(deng)等(deng)(deng)(deng))，在(zai)(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)上(shang)得到類(lei)似正弦的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)波(bo)形。三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)基波(bo)分量的(de)(de)(de)產(chan)生(sheng)矢量為(wei)(wei)零(ling)(ling)，但實際上(shang)每時每刻三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)矢量不為(wei)(wei)零(ling)(ling)，三相(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不平(ping)衡。共(gong)模電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)范圍等(deng)(deng)(deng)于(yu)變(bian)(bian)頻(pin)(pin)(pin)器直流(liu)(liu)側電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，頻(pin)(pin)(pin)率(lv)等(deng)(deng)(deng)于(yu)逆變(bian)(bian)器開關頻(pin)(pin)(pin)率(lv)。共(gong)模電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)通(tong)(tong)過(guo)(guo)固(gu)定轉子(zi)(zi)之(zhi)間的(de)(de)(de)靜電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)耦合在(zai)(zai)(zai)轉子(zi)(zi)軸上(shang)，產(chan)生(sheng)相(xiang)同(tong)頻(pin)(pin)(pin)率(lv)的(de)(de)(de)軸電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。一般變(bian)(bian)頻(pin)(pin)(pin)器逆變(bian)(bian)器側載波(bo)頻(pin)(pin)(pin)率(lv)高(gao)，在(zai)(zai)(zai)10kHz以(yi)上(shang)，定子(zi)(zi)和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)纜(lan)的(de)(de)(de)頻(pin)(pin)(pin)率(lv)過(guo)(guo)高(gao)，產(chan)生(sheng)非常高(gao)的(de)(de)(de)頻(pin)(pin)(pin)率(lv)dv/dt增(zeng)加波(bo)形畸(ji)變(bian)(bian)。由于(yu)靜電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)蓮花，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)各部分之(zhi)間有不同(tong)大小的(de)(de)(de)分布電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)，產(chan)生(sheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)的(de)(de)(de)零(ling)(ling)序(xu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路，通(tong)(tong)過(guo)(guo)軸承的(de)(de)(de)地(di)面(mian)放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)產(chan)生(sheng)軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。通(tong)(tong)常，軸承球漂浮在(zai)(zai)(zai)潤(run)滑脂形成的(de)(de)(de)油(you)膜中。當油(you)膜因某種原因損(sun)壞或(huo)過(guo)(guo)大時，潤(run)滑膜起絕緣作用dv/dt軸承電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)通(tong)(tong)過(guo)(guo)油(you)膜放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，放(fang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)在(zai)(zai)(zai)軸承內外環和球上(shang)燃燒(shao)。長期運行將發展成摩擦板圖案，提高(gao)軸承溫度，熔化潤(run)滑脂，使軸承運行更(geng)差。

2　共模電流路徑

由于靜電(dian)蓮花，電(dian)機(ji)各部分(fen)之(zhi)間有(you)或大(da)或小的(de)(de)分(fen)布電(dian)容，產生電(dian)機(ji)轉(zhuan)(zhuan)子(zi)上共模電(dian)流(liu)的(de)(de)釋放路徑。大(da)多數共模電(dian)流(liu)通過定子(zi)-外(wai)殼(ke)-地(di)板-變頻(pin)(pin)器外(wai)殼(ke)的(de)(de)路徑，少數通過定子(zi)-轉(zhuan)(zhuan)子(zi)-轉(zhuan)(zhuan)子(zi)-軸(zhou)(zhou)(zhou)承(cheng)-外(wai)殼(ke)-地(di)板-變頻(pin)(pin)器外(wai)殼(ke)的(de)(de)路徑。當變頻(pin)(pin)器接地(di)與電(dian)機(ji)外(wai)殼(ke)之(zhi)間的(de)(de)阻(zu)(zu)抗高于變頻(pin)(pin)器外(wai)殼(ke)與負載(zai)(zai)之(zhi)間的(de)(de)阻(zu)(zu)抗時，也會帶來軸(zhou)(zhou)(zhou)向延伸電(dian)流(liu)。通過定子(zi)-外(wai)殼(ke)-旋轉(zhuan)(zhuan)軸(zhou)(zhou)(zhou)-負載(zai)(zai)端軸(zhou)(zhou)(zhou)承(cheng)（電(dian)機(ji)）-旋轉(zhuan)(zhuan)軸(zhou)(zhou)(zhou)-軸(zhou)(zhou)(zhou)承(cheng)（負載(zai)(zai)）-地(di)板-變頻(pin)(pin)器外(wai)殼(ke)的(de)(de)電(dian)路釋放，不僅會危(wei)及電(dian)機(ji)負載(zai)(zai)端軸(zhou)(zhou)(zhou)承(cheng)，還(huan)會危(wei)及負載(zai)(zai)軸(zhou)(zhou)(zhou)承(cheng)和旋轉(zhuan)(zhuan)軸(zhou)(zhou)(zhou)器。后雙共模電(dian)流(liu)通過電(dian)機(ji)軸(zhou)(zhou)(zhou)承(cheng)，第 二種方式(shi)造成更大(da)的(de)(de)危(wei)害。

3　軸(zhou)承電流抑 制的(de)常見措施

抑 制軸(zhou)承(cheng)電(dian)流的(de)方(fang)法(fa)有很多，比(bi)如在變(bian)頻器的(de)導(dao)出側(ce)安裝正弦(xian)波濾波器，以提高(gao)導(dao)出電(dian)流的(de)波形；絕緣電(dian)機一(yi)端的(de)軸(zhou)承(cheng)切斷電(dian)機轉軸(zhou)和軸(zhou)承(cheng)的(de)環流；在電(dian)機輸(shu)出軸(zhou)上安裝接地碳刷(shua)，以抑 制軸(zhou)通過負(fu)載接地的(de)延伸(shen)電(dian)流。這些方(fang)法(fa)可以抑 制相(xiang)應(ying)的(de)方(fang)法(fa)。

4　風機負載端軸承損壞過程(cheng)分析

基于上(shang)述(shu)軸(zhou)(zhou)(zhou)承(cheng)(cheng)電流的(de)原(yuan)理，結合電機的(de)運行狀態，闡(chan)述(shu)了(le)軸(zhou)(zhou)(zhou)承(cheng)(cheng)的(de)損(sun)壞(huai)和(he)(he)(he)故障是一個過程(cheng)。軸(zhou)(zhou)(zhou)承(cheng)(cheng)電流是主要原(yuan)因(yin)。同時，機械(xie)振動和(he)(he)(he)潤滑(hua)脂(zhi)(zhi)消耗是次要原(yuan)因(yin)，促(cu)進了(le)軸(zhou)(zhou)(zhou)承(cheng)(cheng)電流的(de)產(chan)生(sheng)，并(bing)在一定(ding)程(cheng)度(du)上(shang)加(jia)(jia)劇了(le)危害(hai)。風機電機投(tou)入使(shi)用后，由于軸(zhou)(zhou)(zhou)承(cheng)(cheng)間隙對(dui)稱大威脅，因(yin)為(wei)軸(zhou)(zhou)(zhou)承(cheng)(cheng)間隙對(dui)稱，潤滑(hua)充分，潤滑(hua)油膜(mo)對(dui)稱。隨著潤滑(hua)脂(zhi)(zhi)消耗的(de)增(zeng)加(jia)(jia)，負載端振動的(de)增(zeng)加(jia)(jia)首先(xian)導致負載端軸(zhou)(zhou)(zhou)承(cheng)(cheng)間隙的(de)增(zeng)加(jia)(jia)，軸(zhou)(zhou)(zhou)承(cheng)(cheng)電壓的(de)嚴(yan)重(zhong)(zhong)滲透和(he)(he)(he)放(fang)電，軸(zhou)(zhou)(zhou)承(cheng)(cheng)電流的(de)增(zeng)加(jia)(jia)，導致負載端軸(zhou)(zhou)(zhou)承(cheng)(cheng)內部通道的(de)電燃燒、溫度(du)升高和(he)(he)(he)潤滑(hua)脂(zhi)(zhi)液化(hua)，直到軸(zhou)(zhou)(zhou)承(cheng)(cheng)嚴(yan)重(zhong)(zhong)損(sun)壞(huai)和(he)(he)(he)熱損(sun)壞(huai)。因(yin)此，我們認為(wei)應該使(shi)用各種方(fang)法來減少和(he)(he)(he)抑 制軸(zhou)(zhou)(zhou)承(cheng)(cheng)電流。絕緣軸(zhou)(zhou)(zhou)承(cheng)(cheng)和(he)(he)(he)其他方(fang)法暫時不被考慮，因(yin)為(wei)它很難實現。

5　應對策略和實際(ji)效果

采取以下(xia)措施減(jian)少電機發熱和燃(ran)燒。

（1）重新校(xiao)準電機(ji)和負(fu)載，澆筑電機(ji)安裝(zhuang)平臺基礎，增加地(di)(di)腳厚(hou)度，提高電機(ji)地(di)(di)腳剛度，減少(shao)運(yun)行(xing)振(zhen)動；

(2)電機(ji)負載端(duan)軸(zhou)承(cheng)(cheng)(易潤(run)潤(run))在線(xian)潤(run)潤(run)設(she)備Easylube），該設(she)備可以(yi)用(yong)螺(luo)釘固定(ding)在負載軸(zhou)承(cheng)(cheng)的注油(you)孔上。它(ta)使(shi)(shi)用(yong)鋰(li)電池(chi)供電，并(bing)使(shi)(shi)用(yong)全智(zhi)能(neng)芯片和(he)特殊的檢測(ce)設(she)備來控制內部(bu)電機(ji)。它(ta)通過齒輪組驅動(dong)螺(luo)桿和(he)壓板來驅動(dong)活(huo)塞(sai)，并(bing)根據(ju)設(she)定(ding)周期每天分(fen)配(pei)油(you)杯中的潤(run)滑(hua)脂。它(ta)定(ding)期和(he)定(ding)量地(di)(di)注入(ru)軸(zhou)承(cheng)(cheng)，這(zhe)是一個很(hen)好的改進和(he)潤(run)濕(shi)。根據(ju)實際(ji)測(ce)量，在同一環(huan)境下，在線(xian)注油(you)后，負載軸(zhou)承(cheng)(cheng)溫(wen)度(du)降低(di)7℃。根據(ju)電機(ji)軸(zhou)承(cheng)(cheng)潤(run)滑(hua)脂的消耗，設(she)置不同的周期：新電機(ji)、新軸(zhou)承(cheng)(cheng)、環(huan)境溫(wen)度(du)低(di)、設(she)置時間(jian)長、運行時間(jian)長、軸(zhou)承(cheng)(cheng)損壞或環(huan)境溫(wen)度(du)高的設(she)置周期短。這(zhe)種(zhong)靈活(huo)的使(shi)(shi)用(yong)可以(yi)有(you)效地(di)(di)確保軸(zhou)承(cheng)(cheng)有(you)足夠的潤(run)滑(hua)，避免潤(run)滑(hua)脂消耗后的惡性(xing)循環(huan)；

(3)使用10個電機(ji)外殼(ke)和(he)負(fu)載機(ji)械設備mm2上述銅電纜連接(jie)后接(jie)地，與變頻器外殼(ke)和(he)接(jie)地線連接(jie)，電位(wei)相同。這樣可以有效降(jiang)低(di)電機(ji)轉子-外殼(ke)-電機(ji)負(fu)載端軸(zhou)承(cheng)-軸(zhou)-負(fu)載側軸(zhou)承(cheng)-接(jie)地電路的軸(zhou)延電流，降(jiang)低(di)負(fu)載端軸(zhou)承(cheng)的加(jia)熱；

(4)安裝在變頻器輸出側dv/dt濾波器可以減少變頻器輸出電流中的波形畸變，提高電機和電纜的使用壽命，減少(shao)電機和電纜的使用(yong)壽命(ming)dv/dt降(jiang)低軸(zhou)承的峰(feng)值電壓(ya)dv/dt通過峰(feng)值電壓(ya)抑(yi) 制軸(zhou)承電流的產生；

(5)縮短電機軸承的維護周期，每運行4000小時(約6個月)后取出電機，拆卸后檢查軸承的磨損情況，徹 底清(qing)洗并注入脂肪，磨損嚴重時及時更換。

6　結語

通過上述(shu)措施的(de)綜(zong)合實施，電機(ji)(ji)運行(xing)平(ping)穩，完全濕潤(run)，電機(ji)(ji)軸承溫升保持(chi)在可(ke)接受范圍內，電機(ji)(ji)跳閘(zha)設備故(gu)障(zhang)不(bu)再發生，為加熱(re)爐(lu)的(de)生產(chan)創造了良好(hao)的(de)條件。