1. track roller, lower roller, bottom roller
The track roller pass excavator or bulldozer weight on to ground, it will be impacted when excavator is driving rough terrain, so track roller load force large, worse working condition even on dusty situation, sometime in the water. So the track roller is required sealed good.
2. carrier roller, top roller, upper roller
The carrier roller hold up track group, adjust track group tension.
3. sprocket roller/ segment group
the hydraulic excavator power is passed on to track group by travelling motor and sprocket, so the sprocket must match track link and driving smoothly.
4. front idler roller
front idler is used for guide track group correct turning, prevent derailment or deviation. most idler support excavator weight same as track roller. this will expand track group touching ground, decreased press. the distance between idler and nearest track roller is more smaller, the guidance of idler roller for track group is better.
5. track group, track assy, track shoe assy
the track group is including track chain, track shoe, track bolt and nut. track chain have dry type, lubricate type, salt type, sealed and greased type. the width for track shoe can be different, and the track shoe is wider, and pressure will be smaller.