The idler (guide wheel) of bulldozer and some hydraulic excavators also functions as a roller, which can increase the contact area between the crawler and the ground and reduce the specific ground pressure. Most of the wheel surfaces of the idler are smooth, with a shoulder ring in the middle as the guide, and the ring surfaces on both sides can support the chain and the roller. The shoulder ring in the middle of the idler (guide wheel) should have sufficient height and the slope on both sides should be small. The smaller the distance between the guide wheel and the nearest roller, the better the guiding performance. Special heat treatment process results in longer life, the greatest degree of under heavy road, prevent fragmentation. Use low and high-double seal makes it life lubrication, it is suitable for standard and special temperature application.
The idler is composed of collar, idler shell, shaft, seal, o-ring, bushing bronze, lock pin plug, the idler is applicable to special model of crawler type excavators and bulldozers from 0.8T to 100T. It is widely applied in bulldozers and excavators of Caterpillar, Komatsu, Hitachi, Kobelco, Kubota, Yanmar and Hyundai etc, have different manufacturing technology, like casting, welding and forging, use precision processing technology and special heat treatment technique to reach best wear-resistance and have maximum extent loading capacity as well as anti-cracking. 
The function of an idler is to guide the track links into running smoothly and to prevent dislocation, idlers also carry some weight and therefore increasing groud pressure. There is also an arm in the center which supports the track link and guides the two sides. The smaller the distance between the idler and track roller, the better the orientation, our products are according to the standard of OEM to manufacture.