防爆起重機的故障分析及改造方案

1、 故障原因分析

    防(fang)爆(bao)起(qi)重(zhong)機(ji)采(cai)用(yong)的(de)是(shi)直(zhi)流(liu)盤(pan)式(shi)製(zhi)動(dong)器(qi)，屬(shu)於(yu)常(chang)閉(bi)製(zhi)動(dong)器(qi)，斷(duan)電(dian)時(shi)製(zhi)動(dong)器(qi)閉(bi)合(he)

，起(qi)製(zhi)動(dong)作(zuo)用(yong)，通(tong)電(dian)時(shi)製(zhi)動(dong)器(qi)打(da)開(kai)，以(yi)便(bian)電(dian)機(ji)轉(zhuan)動(dong)，主(zhu)要(yao)由(you)整(zheng)流(liu)模(mo)塊(kuai)、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)xuanyongshuangdianyazhengliumokuai。shuangdianyazhengliumokuaideyingyongkejidagaishanzhidongqixianquangongzuodexingneng
，jianshaozhidongqixianquandefare。shuangdianyazhengliumokuairengcaiyongdanxiangqiaoshizhengliudianlu

，bingcaiyongkeguanduandedianzikaiguandianlulaishixianjiangyagongneng。dangzhidongqidakaihou
，zhidongqixianquanbuxuyaotaidadeweichidianliushi
，qizhengliushuchudianyajiangweiquandianyadeyiban
，zheyangjiujianshaolezhidongqixianquandewensheng，zengjialezhidongqixianquandeyunxutongdianshijian，tigaozhidongqixianquangongzuodekekaoxing。qiyuanlirutu1：

 

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)增(zeng)大(da)盤(pan)式(shi)直(zhi)流(liu)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)內(nei)阻(zu)。為(wei)更(geng)進(jin)一(yi)步(bu)提(ti)高(gao)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)工(gong)作(zuo)性(xing)能(neng)，在(zai)采(cai)用(yong)雙(shuang)電(dian)壓(ya)整(zheng)流(liu)模(mo)塊(kuai)為(wei)製(zhi)動(dong)器(qi)線(xian)圈(quan)供(gong)電(dian)的(de)同(tong)時(shi)，采(cai)用(yong)了(le)增(zeng)大(da)製(zhi)動(dong)器(qi)線(xian)圈(quan)內(nei)阻(zu)的(de)方(fang)式(shi)來(lai)降(jiang)低(di)製(zhi)動(dong)器(qi)線(xian)圈(quan)繞(rao)組(zu)的(de)電(dian)流(liu)
，在(zai)保(bao)證(zheng)足(zu)夠(gou)大(da)的(de)電(dian)磁(ci)吸(xi)力(li)以(yi)使(shi)製(zhi)動(dong)器(qi)打(da)開(kai)的(de)前(qian)提(ti)下(xia)，將(jiang)主(zhu)起(qi)升(sheng)電(dian)機(ji)製(zhi)動(dong)器(qi)線(xian)圈(quan)的(de)內(nei)阻(zu)由(you)原(yuan)來(lai)的(de)264Ω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)xuanyongyeyatuiganzhidongqi。yeyatuiganzhidongqishikaotuiganzhongdediandongjidaidongyepianlunxuanzhuan，shiyouyechanshengxiangshangdetuili，bahuosaigantaiqi
，congerdakaizhidongqi。duandianhou，zaizhidongjiazhudanhuangdezuoyongxia，shituigantuihuiyuanlaideweizhi。yeyatuiganzhidongqicaiyongsanxiangjiaoliudian，wuzhengliuhuanjie，shengqulezhengliumokuai，zaidianyuanfangmiankekaoxingjiaozhiliupanshizhidongqiyaogao
，ciwai
，yeyatuiganzhidongqizhidongmocapianzhijieyongtongmaodinganzhuangzaizhidongwakuaishang
，bizhiliupanshizhidongqimocapianyongjiaozhanjie，jianquankekao，youyiguancha，yingjichulishidakaijiaoweifangbianshengshi(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。