Shaft Couplings and Thrust Bearings
Flexible and rigid couplings, torsional couplings and separate thrust bearings, for shaft lines where the gearbox is not carrying the thrust or the torsional behaviour needs changing.
Features
- Flexible couplings accommodate small misalignment and reduce transmitted vibration; they do not license a poorly aligned shaft line.
- Torsional couplings change the stiffness of the driveline and are one of the ways a resonance inside the operating range is moved out of it.
- A separate thrust bearing takes propeller thrust into the hull instead of into the gearbox, which is usual on larger installations.
- Coupling bolts, fits and sealing are part of the specification because a slipping or mis-fitted coupling damages both shaft and flange.
- Alignment tolerance is stated in the installation instruction and checked with dial gauges cold and warm.
Specifications
| Figure | Typical range | Unit | Why it matters |
|---|---|---|---|
| Coupling type | flexible / torsional / rigid | decides what misalignment and torsion it accommodates | |
| Permissible misalignment | 0.1 - 0.5 | mm | the tolerance the alignment is checked against |
| Shaft diameter | 60 - 200 | mm | fixes bore, keyway or taper fit |