如上图中曲线关系可得，星轮对两台车的作用力是有周期性的，即台车在尾部弯道时，开始对星轮的作用力是逐渐增大后又减小，在回程道上达到最大时进而产生起拱。

当台车运行到尾部星轮脱离啮合时，两台车接触端面错位，以锯齿形向头部运动，这种现象称为起拱。长时间以起拱姿态运行，会致使台车产生下滑或者瞬间冲击下落，逐渐形成间隙，导致烧结机漏风，严重时甚至会造成停机事故。

As shown in the curve relationship in the above figure, the force of the star wheel on the two cars is periodic, that is, when the car is in the tail curve, the force on the star wheel starts to increase and then decreases, and in the return journey When the road reaches its maximum, arching occurs.When the trolley runs to the end of the star wheel disengaged, the contact end faces of the two trolleys are misaligned and move toward the head in a zigzag shape. This phenomenon is called arching. Running in an arching posture for a long time will cause the trolley to slide down or fall in an instant, and gradually form a gap, which will cause the sintering machine to leak air, and even cause a shutdown accident in severe cases.