拖拉机前轮的前部总向内收拢一定距离，称为前束。为什么要有前束呢？１．减少前轮胎的磨损为了减少转动方向盘的阻力，前轮都有一个外倾角。这样从轮胎中心做一条和轮胎平面相垂直的线，与地面交与点Ｏ。再以Ｏ向轮缘连线，这样每个前轮就构成一个以Ｏ为顶点的圆锥体（见... The front of the front of the tractor always converge inward a certain distance, called the front beam. Why do you have a toe it? 1. Reduce the front tire wear To reduce the resistance of the steering wheel, the front wheel has a camber angle. In this way, make a line perpendicular to the plane of the tire from the center of the tire, intersecting point O with the ground. Then O to the rim connection, so that each front wheel to form a cone with O as the vertex (see ...