Core Application Areas & Bearing Types

1. Cutterhead Main Drive Bearings (Core): Primarily employ triple-row cylindrical roller combination slewing bearings (internal/external teeth), bearing immense radial forces, bidirectional axial forces, and overturning moments; ROOS-LAIS provides custom oversized versions with reinforced raceways and high-purity bearing steel; Suitable for Earth Pressure Balance (EPB), Slurry Pressure Balance (SLS) shields, and hard rock TBMs. Typically incorporates multiple labyrinth seals + lip seals + pressure lubrication systems to resist ingress of mud/water and sand/gravel.

2. Screw Conveyor (Excavation System): Utilises self-aligning roller bearings, tapered roller bearings, and sealed cylindrical roller bearings; ROOS-LAIS's wear-resistant + extended-life design accommodates low-speed heavy-load operation, frequent start-stop cycles, and silt backflow conditions; some models incorporate sand discharge chamber structures.

3. Cylinder/Hinge Sealing Points: Thrust roller bearings, angular contact ball bearings; designed to withstand axial thrust and eccentric loads; requiring low friction, impact resistance, and reliable sealing.

4. Gearbox/Motor End: Precision cylindrical roller, deep groove ball, and angular contact bearings; ensuring transmission efficiency and rotational precision; ROOS-LAIS offers low-noise models with extended lubrication intervals.

Key Technical Features and Operational Countermeasures

- Materials: Bainite/carburised bearing steel with plasma-sprayed tungsten carbide coating on raceways, achieving hardness up to HV1200+, significantly enhancing wear resistance;

- Lubrication: Extreme-pressure lithium-based/calcium sulfonate composite grease with automatic metered injection, forming a high-pressure oil film for contamination resistance;

- Clearance Optimisation: Minimal clearance in soft soil to prevent seizure; medium/large clearance in hard rock to absorb impacts;

- Customisation: Non-standard dimensions and load verification tailored to shield diameter (3m–15m+), geological conditions, and excavation speed.

Typical Engineering Applications

- Urban metro tunnels (soft soil/composite strata);

- River/sea-crossing tunnels (high hydrostatic pressure, long-distance excavation);

- Mountain railway/road tunnels (hard rock, high impact loads);

- Urban utility tunnel jacking projects.

ROOS-LAIS operates primarily as a bespoke supplier within shield bearing applications rather than a provider of standardised components. Project implementation requires collaborative load simulation, service life calculations, and coordinated seal/lubrication system design with the main equipment manufacturer. On-site installation and maintenance practices significantly impact ultimate service life.