许多沿轨道运行的起重机械,例如桥式和门式起重机,都有较大的跨度(L=20～40米)。对于这类起重机,主动轮如采用单独的电气传动,则在许多情况下,起重机工作时其桥架会发生相当大的歪斜。歪斜的结果是增大了轮缘和轨道接触处的摩擦力,因而增大了轮缘和轨道的磨损。当起重机歪斜很厉害时,车轮也可能打滑。在一系列桥式起重机上进行的观察表明,起重机歪斜 Many orbital hoists, such as bridge and gantry cranes, have large spans (L = 20 to 40 meters). For such cranes, the active wheels, such as with separate electric drives, will, in many cases, cause considerable skew to the cranes during their operation. Askew results in increased friction between the rim and the track contact, thereby increasing the wear of the rim and the track. When the crane is awkward, the wheels may slip. Observations on a series of overhead traveling cranes showed that the crane was skewed