防爆起重機是某施工工地用於大型設備的卸車、安裝、調試、duijiedengzuoyedeguanjianshebei。gaiqizhongjijuyoujiegoufuza，suochuhuanjingelie，weihubaoyangnandudadengtedian。zhidongzhuangzhishigaishebeideguanjianbujian，qikekaoxingzhijieguanxidaodiaozhuanggongzuodeanquan。zaijin5年的使用期間，該防爆起重機製動器共出現故障26次，占吊裝設備故障總量的56.6％。製動器出現故障的主要部位是製動器線圈、整流模塊和摩擦片3部分，其中最易出問題的是整流模塊和製動器線圈。為此，對起重機的製動器進行了技術改造。
1 故障原因分析
fangbaoqizhongjicaiyongdeshizhiliupanshizhidongqi，shuyuchangbizhidongqi，duandianshizhidongqibihe，qizhidongzuoyong，tongdianshizhidongqidakai，yibiandianjizhuandong，zhuyaoyouzhengliumokuai、直流線圈、摩擦片、製動盤和製動彈簧組成。
(1)吊車連續運行時間長而得不到充分散熱，將導致製動器溫升過高，絕緣材料失效而致使線圈匝間短路，從而燒毀製動器線圈；
(2)製動器線圈過載燒毀時產生的過電流擊穿了整流模塊的二極管；另一方麵是自身質量不過關，主要原因是印刷板質量差，元器件篩選不過關等因素也可能導致整流模塊的燒毀；
(3)由(you)於(yu)製(zhi)動(dong)器(qi)調(tiao)整(zheng)的(de)間(jian)隙(xi)小(xiao)，電(dian)動(dong)機(ji)運(yun)行(xing)中(zhong)不(bu)能(neng)避(bi)免(mian)摩(mo)擦(ca)片(pian)與(yu)製(zhi)動(dong)盤(pan)問(wen)的(de)摩(mo)擦(ca)，電(dian)動(dong)機(ji)多(duo)次(ci)長(chang)時(shi)間(jian)運(yun)行(xing)後(hou)，將(jiang)使(shi)摩(mo)擦(ca)片(pian)溫(wen)度(du)升(sheng)高(gao)，粘(zhan)接(jie)膠(jiao)因(yin)過(guo)熱(re)失(shi)效(xiao)，致(zhi)使(shi)製(zhi)動(dong)器(qi)摩(mo)擦(ca)片(pian)粘(zhan)接(jie)處(chu)開(kai)裂(lie)，加(jia)速(su)了(le)電(dian)動(dong)機(ji)和(he)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)發(fa)熱(re)，並(bing)伴(ban)隨(sui)異(yi)常(chang)噪(zao)聲(sheng)。長(chang)時(shi)間(jian)運(yun)行(xing)將(jiang)導(dao)致(zhi)電(dian)動(dong)機(ji)和(he)製(zhi)動(dong)器(qi)線(xian)圈(quan)絕(jue)緣(yuan)的(de)損(sun)壞(huai)，燒(shao)毀(hui)電(dian)動(dong)機(ji)或(huo)製(zhi)動(dong)器(qi)。
2 改造方案
(1)選(xuan)用(yong)雙(shuang)電(dian)壓(ya)整(zheng)流(liu)模(mo)塊(kuai)。雙(shuang)電(dian)壓(ya)整(zheng)流(liu)模(mo)塊(kuai)的(de)應(ying)用(yong)可(ke)極(ji)大(da)改(gai)善(shan)製(zhi)動(dong)器(qi)線(xian)圈(quan)工(gong)作(zuo)的(de)性(xing)能(neng)，減(jian)少(shao)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)發(fa)熱(re)。雙(shuang)電(dian)壓(ya)整(zheng)流(liu)模(mo)塊(kuai)仍(reng)采(cai)用(yong)單(dan)相(xiang)橋(qiao)式(shi)整(zheng)流(liu)電(dian)路(lu)，並(bing)采(cai)用(yong)可(ke)關(guan)斷(duan)的(de)電(dian)子(zi)開(kai)關(guan)電(dian)路(lu)來(lai)實(shi)現(xian)降(jiang)壓(ya)功(gong)能(neng)。當(dang)製(zhi)動(dong)器(qi)打(da)開(kai)後(hou)，製(zhi)動(dong)器(qi)線(xian)圈(quan)不(bu)需(xu)要(yao)太(tai)大(da)的(de)維(wei)持(chi)電(dian)流(liu)時(shi)，其(qi)整(zheng)流(liu)輸(shu)出(chu)電(dian)壓(ya)降(jiang)為(wei)全(quan)電(dian)壓(ya)的(de)一(yi)半(ban)，這(zhe)樣(yang)就(jiu)減(jian)少(shao)了(le)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)溫(wen)升(sheng)，增(zeng)加(jia)了(le)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)允(yun)許(xu)通(tong)電(dian)時(shi)間(jian)，提(ti)高(gao)製(zhi)動(dong)器(qi)線(xian)圈(quan)工(gong)作(zuo)的(de)可(ke)靠(kao)性(xing)。其(qi)原(yuan)理(li)如(ru)圖(tu)1：
圖1 雙電壓整流模塊電氣原理圖
1、過電壓保護 2、半波整流 3、電子開關 4、時間控製 5、全波整流
(2)zengdapanshizhiliuzhidongqixianquandeneizu。weigengjinyibutigaozhidongqixianquandegongzuoxingneng，zaicaiyongshuangdianyazhengliumokuaiweizhidongqixianquangongdiandetongshi，caiyonglezengdazhidongqixianquanneizudefangshilaijiangdizhidongqixianquanraozudedianliu，zaibaozhengzugoudadediancixiliyishizhidongqidakaideqiantixia，jiangzhuqishengdianjizhidongqixianquandeneizuyouyuanlaide264Ω增大到304Ω。降低了製動器線圈繞組的電流，從而最大限度改善了電機製動器的性能，經測試，現製動器線圈通電1 h(采用原整流模塊，線圈輸入直流電壓34 V)，製動器線圈溫升隻有80℃，且不再上升，達到了穩定溫升。
(3)選用液壓推杆製動器。液ye壓ya推tui杆gan製zhi動dong器qi是shi靠kao推tui杆gan中zhong的de電dian動dong機ji帶dai動dong葉ye片pian輪lun旋xuan轉zhuan，使shi油you液ye產chan生sheng向xiang上shang的de推tui力li，把ba活huo塞sai杆gan抬tai起qi，從cong而er打da開kai製zhi動dong器qi。斷duan電dian後hou，在zai製zhi動dong架jia主zhu彈dan簧huang的de作zuo用yong下xia，使shi推tui杆gan退tui回hui原yuan來lai的de位wei置zhi。液ye壓ya推tui杆gan製zhi動dong器qi采cai用yong三san相xiang交jiao流liu電dian，無wu整zheng流liu環huan節jie，省sheng去qu了le整zheng流liu模mo塊kuai，在zai電dian源yuan方fang麵mian可ke靠kao性xing較jiao直zhi流liu盤pan式shi製zhi動dong器qi要yao高gao，此ci外wai，液ye壓ya推tui杆gan製zhi動dong器qi製zhi動dong摩mo擦ca片pian直zhi接jie用yong銅tong鉚mao釘ding安an裝zhuang在zai製zhi動dong瓦wa塊kuai上shang，比bi直zhi流liu盤pan式shi製zhi動dong器qi摩mo擦ca片pian用yong膠jiao粘zhan接jie，既ji安an全quan可ke靠kao，又you易yi觀guan察cha，應ying急ji處chu理li時shi打da開kai較jiao為wei方fang便bian省sheng時shi(手動即可打開)。由於采用了防爆措施，製動器仍滿足改造前的防爆要求。