The main reason is as follows : dust in lifting rail is not removed clean ; lifting rail is not at a level ; the installation of low locator is not correct ; regulate screw in lifting wheel regulates too high 趟动门钰感觉不顾滑，主要原因有：吊轨里的灰尘没清除干净吊轨不够水平下定位安装不准确和吊轮调节螺丝调节过高造成。
