Tunnel Boring Machines
Slewing bearings in tunnel boring machines (TBM)
Large and heavy triple-row roller slewing bearings are commonly used as the primary bearing in the drill head. The rollers must be capable of withstanding tremendous axial forces and are therefore equipped with cages.
The positioning of tubbing segments during tunnel construction can be achieved with the assistance of crossed-roller slewing bearings. Additionally, bearings may be outfitted with steel sheets or a steel labyrinth to protect the sealings from dirt and debris.