Drum gear couplings are mandatory in three mobile/heavy sectors:
- Rail transit: traction gearboxes, EMU drive — high torque, shock-proof, low-maintenance priority.
- Cranes: hoist/slewing — shock loads, high torque, off-center resistance.
- Turbine (auxiliary / low-speed end): big-torque aux drives; the pure high-speed spool usually uses a diaphragm coupling.
Selection focus: peak torque × safety factor, operating temperature, explosion-proof/corrosion needs. Drawing-based orders follow shaft ends and layout.