Can a Car Alternator be Submerged in Oil for Underwater Power Generation?

In summary, the Alternator will be submerged in oil to help it turn and charge the batteries. It is unknown if the Alternator's bearings can handle the force, and it is unknown what the speed of the propellor will be.
  • #1
derek-CT
2
0
Hi

I need to build a 12V alternator inside a pressure casing that will be driven by a propellor. This will be mounted on the rear on an oceanographic sensor platform that will be towed behind a ship on a long cable with the ship's forward motion providing the spinning of the prop, for the alternator to charge batteries (very low gassing) and run electronics.

The ship's speed will vary between 2 and 10knots. The ideal current output would be between 6 and 10 Amps. Ideal operating depth would be 1000m to allow "sinking" when the ship slows.

I envisage a small car alternator inside a pressure casing. The problem is the link shaft through the case to connect the alternator to the prop.

I can o-ring seal it, but at depth the pressure on the o-rings will "pinch" the shaft.

There are also magnetic couplings, as a last resort.

My question...

anyone have any experience in running a car alternator submerged in light oil? If I can fill the casing with oil, I won't have to do such radical shaft sealing.

Thanks in advance.

Derek
 
Engineering news on Phys.org
  • #2
I don't have any experience running an alternator submerged in oil, but my gut instinct would be that any kind oil around the alternator would severly impead its ability to turn at a speed sufficient to generate the required amps.

Jim
 
  • #3
The first thing that pops into my head is whether or not the windings and associated coatings are made to be submerged. I have seen plenty of oil cooled generators so this is nothing new, but using something that is normally air cooled may cause a bit of a problem. I'll have to ask around to see if anyone I know knows the answer to that.

Can you tell me what the size of the shaft is and what the max rotational speed is? I would like to take a look at the sealing of the shaft too.
 
  • #4
Thanks for the replies...

>Can you tell me what the size of the shaft is and what the max rotational speed is? I would like to take a look at the sealing of the shaft too.

If we use a standard car alternator, we will have to extend the shaft to penetrate the casing. I guess work on a 13mm (1/2") diameter, with a small outboard engine prop.

Have not done sums on prop pitch and speeds needed to produce 6 to 10A, as first need to see if whole sealing concept will make the idea feasible.

I'm geared up to produce o-ring sealed cases that survive 6000m, but penetrating with a spinning shaft at 1000m is a challenge.

Other issues are if a car alternator's bearings will handle the pulling force on the shaft will the drag of the prop.

Thanks.

Derek
 

What is an oil filled 12V alternator?

An oil filled 12V alternator is an electrical device that converts mechanical energy into electrical energy. It is filled with oil to provide lubrication and cooling for its internal components.

How does an oil filled 12V alternator work?

An oil filled 12V alternator uses a rotating magnetic field created by a rotor and stationary coils of wire to produce an alternating current (AC). This AC is then converted to direct current (DC) by a rectifier and used to charge the vehicle's battery and power the electrical systems.

What are the benefits of using an oil filled 12V alternator?

An oil filled 12V alternator has several benefits including better cooling and lubrication for its internal components, higher efficiency, and longer lifespan compared to air-cooled alternators.

How do you maintain an oil filled 12V alternator?

To maintain an oil filled 12V alternator, it is important to regularly check the oil level and change it as recommended by the manufacturer. It is also important to keep the alternator clean and free of debris to ensure proper functioning.

Can an oil filled 12V alternator be repaired?

In most cases, an oil filled 12V alternator can be repaired if it is not functioning properly. This typically involves replacing worn or damaged parts such as the brushes, bearings, or diodes. However, if the damage is extensive, it may be more cost-effective to replace the alternator entirely.

Back
Top