Eli5: How does water not get inside ships or submarines through the motor shaft?

709 views

Eli5: How does water not get inside ships or submarines through the motor shaft?

In: 112

13 Answers

Anonymous 0 Comments

If water has a path, with pressure and time it will leak. Everything leaks. Solid metal impurities diffuses straight through solid metal, not quickly though. So we apply many different methods, sometimes in combination, to reduce leakage.

Looking up seals and packings for valve stems, large rotor shafts, turbine shafts, or just boat motor methods. Common ones are flanges and plates with complex paths, redirecting the pressure of the water back on itself, stuffing compressed material around the shaft so it squeezes the water back out, and using pressurized oil to create a seal against the water. Nothing will do the job for ever, maintenance is always needed, vibrations and wear will create an uneven surface over time and water will channel down those paths. It all depends on how long you can go before major repairs and what stresses you will be putting on the system. Sometimes just letting it leak and running a little pump and collection tank constantly is a fine solution.

You are viewing 1 out of 13 answers, click here to view all answers.