一、小车三条腿的概念所谓小车三条腿,即小车的四个车轮只有三个接触轮道,另外一个车轮悬空或轮压甚小。桥式起重机的小车车架与桥架(大车)相比,其跨度小而刚性很大,所以三条腿的现象在小车上是常见的。尤其是5吨和10吨的双梁桥式起重机,小车轨距一般仅1400～2000毫米, First, the concept of three-car car The so-called car three legs, the car’s four wheels only three contact wheel, another wheel vacant or wheel pressure is very small. Compared with the bridge (cart), the overhead crane’s trolley frame has small span and high rigidity, so the three-legged phenomenon is common on the trolley. In particular, 5 tons and 10 tons of double-girder overhead crane, trolley gauge is generally only 1400 ~ 2000 mm,