Mechanical BC's - is it possible?

[fisherdvm]

If there are any engineering inventor types here, I would like their input. People laughed when a doctor suggested 30 years ago that a laser can be used in cosmetic applications, so don't laugh at me too hard.

As we all use inflatable bladder like BC's, which are simple, but have to obey the laws of physics. They gain bouyancy at the surface, and lose bouayancy at depth.

Why can't we just have a mechanical BC, that is not compressible, so that our bouyancy is more constant.

The idea is a rigid BC, using mechanical gears, and screws. A motor or a manual crank is used to increase and decrease the size of a rigid cylinder with a piston. Kinda like a syringe when you capped the end.

The force needed is simply the force required to create a vacumm or pressurize the inert gas in the cylinder. We are not adding or subtracting air, just simply increasing or decreasing the pressure in the cylinder.

The adventage of the system - no fluctuation in buoyancy due to the BC. The disadvantage, it is rigid and too many parts to break.

 

[SparticleBrane]

If there's no fluctuation of in buoyancy, then it sounds to me like you wouldn't be able to change your buoyancy at depth. Kinda defeats the purpose doesn't it?

 

[MikeFerrara]

There are probably lots of problems with the design you suggest. A couple might be keeping the moving parts sealed and the force needed to expand and contract it.

It wouldn't be too hard to add a closed loop control system to a bladder bc. I think that would get you what you want but why would you want it?

 

[dive_lover88]

i think you would need swim rings instead of weights to compansate the weight of the gears.

 

[Thalassamania]

There are devices like you describe (cylinder, worm gear, motor. etc) to control buoyancy for small ROVs. They’re coupled with a pressure transducer and control circuit and do a great job maintaining position in the water column. I guess the same thing could be done with a couple of tubes on the side of tank. It could work.

 

[oly5050user]

how would it compensate for suit compression? Lung volume changes?How would you make yourself negative to stop and work on something?How to make yourself positive on surface?

 

[dkktsunami]

BC is compensating for change of buoyancy of your body and your exposure suit. If it doesn't change size how is this going to be accomplished?

 

[Thalassamania]

If you apply the ROV concept then you'd have a "stay here" button that you'd press and it would keep you there. You'd program the control circuit to manually click off or click off automatically with a change of a few PSI (like a cruise control on a car). I guess you could use a similar control circuit with two solenoids on one of the newfangled BCs.

 

[The Chairman]

Many of us ALSO wear compressable neopreme. The extra air we add at depth compensates for this as well as other compressible areas and not just the BC.

 

[Thalassamania]

Many of us ALSO wear compressable neopreme. The extra air we add at depth compensates for this as well as other compressible areas and not just the BC.

It's just a question of how much water the system would have to displace and how fast it would have to react. Oh ... and do you trust it?

I still have the greatest confidence in the mission Dave.