Examples of Marine Couplings.
| Diameter of shaft | 23⁄8 | 9¾ | 127⁄8 | 16½ | 22½ | 23 |
|---|---|---|---|---|---|---|
| Diameter of flange | 6 | 19 | 24 | 32 | 35 | 38 |
| Thickness of flange | 1 | 2¾ | 31⁄8 | 4¼ | 6 | 5 |
| Diameter of bolts | ¾ | 2¾ | 211⁄16 | 3½ | 4¼ | 4¼ |
| Number of bolts | 3 | 6 | 6 | 8 | 9 | 8 |
| Diameter of bolt circle | 41⁄8 | 141⁄8 | 1813⁄16 | 25 | 28¾ | 303⁄8 |
All the above dimensions are in inches.
Exercise 23.—Select one of the couplings from the above table, and make the necessary working drawings for it to a suitable scale.
The cast-iron flange coupling is shown in fig. 24. In this kind of coupling a cast-iron centre or boss provided with a flange is secured to the end of each shaft by a sunk key driven from the face of the flange. These flanges are then connected by bolts and nuts as in the marine coupling.
To ensure the shafts being in line the end of one projects into the flange of the other.
In order that the face of each flange may be exactly perpendicular to the axis of the shaft they should be 'faced' in the lathe, after being keyed on to the shaft.
If the coupling is in an exposed position, where the nuts and bolt-heads would be liable to catch the clothes of workmen or an idle driving band which might come in the way, the flanges should be made thicker, and be provided with recesses for the nuts and bolt-heads.
Fig. 24.