槽形托辊一般由两个侧托辊和一个平托辊组成，槽角度一般为30度，对于可拆卸式的带式输送机，槽形托辊的三个托辊互相铰接在一起，故称铰接托辊。平行托辊一般为一个长辊，它安装在承受压力的下端故称下托辊。
The troughed idler is generally composed of two side idler and a flat idler, and the groove angle is generally 30 degrees. For the detachable belt conveyor, the three rollers of the troughed idler are hinged to each other, so it is called the articulated idler. The parallel idler is generally a long roller, which is installed at the lower end under pressure, so it is called the lower idler.