一、起重機(ji)的(de)供電(dian)特(te)點

交(jiao)流起(qi)(qi)重(zhong)機(ji)電(dian)(dian)(dian)源由公共的(de)(de)交(jiao)流電(dian)(dian)(dian)網供電(dian)(dian)(dian)，由于(yu)(yu)起(qi)(qi)重(zhong)機(ji)的(de)(de)工作是經(jing)常移動的(de)(de)，因(yin)此(ci)其(qi)與(yu)電(dian)(dian)(dian)源之間(jian)不能采用固定(ding)連接(jie)方式(shi)，對(dui)于(yu)(yu)小型(xing)起(qi)(qi)重(zhong)機(ji)供電(dian)(dian)(dian)方式(shi)采用軟電(dian)(dian)(dian)纜(lan)供電(dian)(dian)(dian)，隨(sui)著大車或小車的(de)(de)移動，供電(dian)(dian)(dian)電(dian)(dian)(dian)纜(lan)隨(sui)之伸展和疊卷。對(dui)于(yu)(yu)一般橋(qiao)式(shi)起(qi)(qi)重(zhong)機(ji)常用滑(hua)線和電(dian)(dian)(dian)刷供電(dian)(dian)(dian)。三(san)(san)相交(jiao)流電(dian)(dian)(dian)源接(jie)到沿車間(jian)長度(du)方向架(jia)設(she)的(de)(de)三(san)(san)根(gen)主滑(hua)線上，再通過電(dian)(dian)(dian)刷引到起(qi)(qi)重(zhong)機(ji)的(de)(de)電(dian)(dian)(dian)氣設(she)備上，首入駕(jia)駛室中(zhong)的(de)(de)保(bao)護盤上的(de)(de)總電(dian)(dian)(dian)源開關，然(ran)后再向起(qi)(qi)重(zhong)機(ji)各電(dian)(dian)(dian)氣設(she)備供電(dian)(dian)(dian)。對(dui)于(yu)(yu)小車及其(qi)上的(de)(de)提升機(ji)構(gou)等電(dian)(dian)(dian)氣設(she)備，液壓支柱供應，則經(jing)位于(yu)(yu)橋(qiao)架(jia)另一側的(de)(de)輔(fu)助滑(hua)線來供電(dian)(dian)(dian)。

滑線(xian)通常(chang)用(yong)角鋼(gang)、圓(yuan)鋼(gang)、V形鋼(gang)軌來制成。當(dang)電流值很(hen)大(da)或(huo)滑線(xian)太長時，為減少滑線(xian)電壓降，常(chang)將(jiang)角鋼(gang)與(yu)鋁排逐斷(duan)并聯，以減少電阻值。在(zai)交流系統中，圓(yuan)鋼(gang)滑線(xian)因趨(qu)膚效應的影響，只(zhi)適用(yong)于(yu)短線(xian)路(lu)或(huo)小電流的供電線(xian)路(lu)。

二、電路構成

10t交流(liu)橋(qiao)式(shi)起(qi)重機(ji)(ji)電(dian)(dian)(dian)(dian)氣控(kong)制(zhi)的(de)全電(dian)(dian)(dian)(dian)路(lu)如圖8－10所示(shi)。10t橋(qiao)式(shi)起(qi)重機(ji)(ji)只有一(yi)個吊鉤，但大車采用(yong)分(fen)別(bie)(bie)驅(qu)動(dong)(dong)(dong)，所以共用(yong)了四(si)臺(tai)繞線(xian)轉(zhuan)子異步(bu)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)拖動(dong)(dong)(dong)。起(qi)重電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)M1、小車驅(qu)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)M2、大車驅(qu)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)M3和M4；分(fen)別(bie)(bie)由(you)三只凸輪控(kong)制(zhi)器控(kong)制(zhi)：QM1控(kong)制(zhi)M1、QM2控(kong)制(zhi)M2、QM3同步(bu)控(kong)制(zhi)M3與M4；R1～R4分(fen)別(bie)(bie)為四(si)臺(tai)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)轉(zhuan)子電(dian)(dian)(dian)(dian)路(lu)串(chuan)入(ru)的(de)調速電(dian)(dian)(dian)(dian)阻器；YB1～YB4則分(fen)別(bie)(bie)為四(si)臺(tai)電(dian)(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)的(de)制(zhi)動(dong)(dong)(dong)電(dian)(dian)(dian)(dian)磁鐵(tie)。三相電(dian)(dian)(dian)(dian)源由(you)QS1引入(ru)，液壓支柱價格(ge)，并由(you)接觸器KM控(kong)制(zhi)。過(guo)(guo)流(liu)繼(ji)電(dian)(dian)(dian)(dian)器KI0～KI4提供(gong)過(guo)(guo)電(dian)(dian)(dian)(dian)流(liu)保(bao)護(hu)(hu)，其中(zhong)(zhong)KI1～KI4為雙線(xian)圈式(shi)，分(fen)別(bie)(bie)保(bao)護(hu)(hu)M1、M2、M3與M4；KI0為單(dan)(dan)線(xian)圈式(shi)，單(dan)(dan)獨串(chuan)聯在主(zhu)電(dian)(dian)(dian)(dian)路(lu)的(de)一(yi)相電(dian)(dian)(dian)(dian)源線(xian)中(zhong)(zhong)，作總電(dian)(dian)(dian)(dian)路(lu)的(de)過(guo)(guo)電(dian)(dian)(dian)(dian)流(liu)保(bao)護(hu)(hu)。

該電(dian)路(lu)(lu)(lu)的(de)控(kong)制(zhi)(zhi)原(yuan)理(li)已在分(fen)析圖(tu)2-6時介紹(shao)過，不同的(de)是(shi)凸輪控(kong)制(zhi)(zhi)器QM3共有(you)17對觸點(dian)，比QM1、QM2多了五對觸點(dian)，用于控(kong)制(zhi)(zhi)另(ling)一臺電(dian)動機的(de)轉子(zi)電(dian)路(lu)(lu)(lu)，因此可(ke)以(yi)同步控(kong)制(zhi)(zhi)兩臺繞線轉子(zi)異步電(dian)動機。下面主(zhu)要介紹(shao)該電(dian)路(lu)(lu)(lu)的(de)保護(hu)電(dian)路(lu)(lu)(lu)部分(fen)。

起(qi)重機司機操(cao)作時(shi)，應遵守(shou)下列(lie)技術(shu)要(yao)求：

1、不(bu)得利用極(ji)限位置限制器停車；

2、不得在(zai)有(you)載荷的情(qing)況下調整起升、變幅機構的制動器；

3、吊(diao)運(yun)時，不得從人的上空通過，吊(diao)臂下(xia)不得有人；

4、起重(zhong)機工作時不得進行檢查和維(wei)修(xiu)；

5、所吊(diao)重(zhong)物(wu)接近或(huo)達(da)到額定起重(zhong)能(neng)力時，吊(diao)運前應檢查制動器，液壓支柱制造商，并用小高度、短行程試(shi)吊(diao)后，再平穩地吊(diao)運；

6、無(wu)下降極(ji)限位置限制器的起重機，東(dong)營液(ye)壓支(zhi)柱，吊鉤在工作(zuo)位置時(shi)，卷筒上的鋼絲繩必(bi)須(xu)保持有設計(ji)規(gui)定的安全圈數；

7、起重(zhong)機工作時，臂(bei)架、吊具、輔具、鋼絲繩、纜(lan)風(feng)繩及重(zhong)物等，與輸電線的距離不(bu)應小于下表的規(gui)定。

螺栓擰得太緊

工(gong)程機械(xie)在拆裝過程中，很多(duo)部位的(de)螺(luo)栓都是(shi)有(you)規(gui)定轉矩要求(qiu)的(de)，比如傳動箱、汽缸蓋、輪轂、連桿和前橋(qiao)等部位，擰緊力矩在說明(ming)書中都有(you)專(zhuan)門規(gui)定，切(qie)不可隨意改(gai)變。

但(dan)是(shi)很(hen)多使用人(ren)員都誤認為緊(jin)一些會更安全，但(dan)是(shi)擰得(de)太(tai)緊(jin)會造成螺釘或螺栓折斷(duan)，也可能由于螺紋滑扣而(er)引起(qi)故障(zhang)。

8.輪胎氣壓太高

輪式工程機械的(de)輪胎充氣壓(ya)力是(shi)決定其使(shi)用壽命和工作效率(lv)的(de)重要(yao)因(yin)素。

輪胎氣壓過(guo)高(gao)或過(guo)低都(dou)會(hui)影響其使用壽命，同時也不(bu)利于安全(quan)行車，尤其是在炎熱的(de)夏季。

科(ke)學(xue)的充氣(qi)標準(zhun)應該是：以輪胎的標準(zhun)氣(qi)壓為(wei)基準(zhun)，隨(sui)著氣(qi)溫的變(bian)化，對輪胎氣(qi)壓略有調整才對。

例如(ru)：夏(xia)季應比冬季低(di)(di)5%-7%，因考(kao)慮到夏(xia)季氣溫(wen)高，氣體受熱，壓力，相反冬季必須(xu)達(da)到標準氣壓或(huo)略低(di)(di)一(yi)點。