用平衡滑轮补偿的单臂起重机是水平变幅起重机的一种。它与四连杆起重机相比,虽然臂架下面的空间有所减少,最小幅度也大一点,但它的水平性可接近四连杆起重机,而变幅时速度变化比较小。它的主要优点是构造简单,可使臂架系统的重量减轻30%左右,因而用钢量少,造价便宜,加工的工艺性也比四连杆式好。从钢丝绳的磨损来看,它比用滑轮组补偿好。由于它具有这些优点,近年在大起重量、大幅度的高架起重机里应用得越来越多。 One-arm cranes compensated by balance wheels are a type of horizontal luffing crane. Compared with the four-link crane, although the space below the boom is reduced and the minimum amplitude is larger, it is nearly horizontal to the four-link crane with less change in amplitude during the luffing. Its main advantage is the simple structure, can reduce the weight of the boom system about 30%, so less steel, low cost, process technology is better than the four-link. From the rope wear point of view, it is better than using pulley block compensation. Because of these advantages, it has been applied more and more in large lifting and large-scale overhead cranes in recent years.