头部驱动滚筒或尾部改向滚筒的轴线与输送机中心线不垂直，造成输送带在头部滚筒或尾部改向滚筒处跑偏。滚筒偏斜时，输送带在滚筒两侧的松紧度不一致，沿宽度方向上所受的牵引力Fq也就不一致，成递增或递减趋势，这样就会使输送带附加一个向递减方向的移动力Fy,导致输送带向松侧跑偏，即所谓的"跑松不跑紧".
The axis of the head driving roller or the tail reversing roller is not perpendicular to the conveyor center line, which causes the conveyor belt to run off at the head roller or the tail reversing roller. When the drum is skewed, the tightness of the conveyor belt on both sides of the drum is not the same, and the traction force FQ along the width direction is not the same, which is increasing or decreasing. In this way, a moving force FY in the decreasing direction will be added to the conveyor belt, resulting in the conveyor belt running to the loose side, that is, the so-called "running loose or running tight"
其调整方法为：对于头部滚筒如输送带向滚筒的右侧跑偏，则右侧的轴承座应当向前移动，输送带向滚筒的左侧跑偏，则左侧的轴承座应当向前移动，相对应的也可将左侧轴承座后移或右侧轴承座后移。尾部滚筒的调整方法与头部滚筒刚好相反。经过反复调整直到输送带调到较理想的位置。在调整驱动或改向滚筒前最好准确安装其位置。
The adjustment method is as follows: for the head drum, if the conveyor belt deviates from the right side of the drum, the bearing pedestal on the right side shall move forward, and if the conveyor belt deviates from the left side of the drum, the bearing pedestal on the left side shall move forward, and correspondingly, the bearing pedestal on the left side can also move backward or the bearing pedestal on the right side. The adjustment method of the tail roller is just opposite to that of the head roller. Adjust repeatedly until the conveyor belt is in a better position. It is better to install the driving or reversing drum accurately before adjusting it.