升降货梯在使用一段时间后，容易出现杂音，设备出现尖叫声的主要原因：

1、升降货梯滑块磨损严重或润滑状况较差，因非正常使用造成丝杆变形，使丝杆螺母运动过程发生抖动。
Zhejiang Huoti slider badly worn or poor lubrication conditions, because of the non-normal use screw deformation, so that the screw nut jitter occurs during exercise.

2、螺母磨损严重，升降货梯导轨工作面有杂质双柱举升机的保险装置包括哪些内容包括上、下限位行程开关、安全螺母、同步保险装置、三角带超负荷打滑、托臂自锁、二级臂限位螺钉、托盘限位套。
Nuts badly worn, Zhejiang rail freight elevator impurities Face Lift safety device includes two columns which includes upper and lower position limit switch, safety nut, synchronous safety device, belt slippage overload, corbel self-locking, two limit screw arm, tray limit sets.