Another wiew on gravity wheel - vacuum controlled under-water wheel

[Low-Q]

Hi,

I have made a drawing here. It contains four containers which has an altering volume of vacuum. To decrease or increase a volume of vacuum takes the equal amount of energy regardless of the initial volume.
If the containers was filled with air, it would take much more energy to decrease volume than increasing the volume.

The altering volume in the containers are controlled by spokes attached to a rod or axis outside the axis of the main wheel where the containers are attached. The pull force on each spoke are equal regardless of container position - this due to the vacuum inside the containers. So there is in sum, no forces at all required to alter the volume inside them. Vacuum is vacuum, hence force equals counterforce.

That said, what will happen if we put this wheel under water?

Will the container with most volume rise, the one with no volume go down?

Will the wheel find its rest at the very position in the drawing, or will it continue to rotate (counter clockwise in this case)?

Please discuss

Br.

Vidar

[Hankinator]

Vidar,

Looks interesting.  Long ago a similar idea was discussed inside a thread here: http://www.overunity.com/index.php?topic=388.0. Post #23

Instead of using a cam or offeset hub to displace the water it's proposed to use weights as close to the axis as possible.  I think these ideas are brothers.

I have been slowly working on a build of this.  It's very difficult to prototype.  Everything has to be sealed water tight and a suitable sized water container has to be found for testing.  This makes the scale I can build and test inside the house fairly small.

Your idea interests me.  Any next steps to a build in mind?

Keep us posted.

Thanks,

Hankinator

[Low-Q]

This is just an idea that crossed my mind in a hurry. I have to calculate any time- and distance issues in one round of the wheel to determind if there is a good idea building one. Time of travel, plus the Net density of left versus right side of the wheel, plus the amount of time during one round the density differences are present, must be calculated. One direct thought of an obstacle is the effect of the spokes and how they interfere with the energy required to pull out the membrane on different places in the wheels position. I will however assume that the energy spent to decrease and increase the volume in the boxes during one revolution are cancelled out, but some friction must be taken into account. If the thing works, it will be a matter of engineering how to reduce friction to a minimum, so the total torque is sufficient to make it work even with small friction.

The buoyancy of the highest and lowest box should be equal, but the force to achieve the same volume will be less at the highest box than the lowest one. This might be the "key" to a non working device. However, the spokes are fixed, and the question is if this wheel will just cog a bit, but if the sum of forces is zero during one round (As it in, my mind, should be), cogging should not be an issue to stop the device from working.

I think this is an interesting approach to a gravity wheel.

As a start one can try to use medical injectors and lubricate them with silicon oil to reduce friction. They are capable of sustaining total vacuum for a long time - just to test out the idea.

br.

Vidar

[Low-Q]

I have done some calculations if I use medical injectors. I have a pair of those, and the friction in them are quite low if I lubricate them with silicone oil. If I manage to make a system that makes at max 10ml of emty volume, and a diameter of approx 50cm, I will have an average torque of 0,025Nm with two small 10ml medical injectors. It takes at about 50g to move the piston in the medical injector due to friction. Devided by the relationship between length of stroke and the total radius, the energy required to move the pistons should be less than the energy coming out of the torque in the wheel. This experiment should work - if I haven't missed something.

Br.

Vidar

[TinselKoala]

Unfortunately it will take slightly more force to pull the 10 cc of vacuum at the bottom of the wheel than the vacuum will return at the top. This is because of the additional pressure of the water column. So the system won't move on its own.

Besides, buoyancy is just gravity under water. Consider the case of a big globule of water floating in zero-g. Now introduce a bubble into the center (with your medical syringe?)  Will the bubble "float" to the surface by buoyancy? Of course not. (It will eventually reach the surface, but not by buoyancy.) Buoyancy is an effect of gravity, nothing more or less. So, if we can agree that gravity wheels can't work, because gravity is a conservative field, by extension, buoyancy wheels can't work either, no matter how clever the mechanism.
In fact, the drag of pushing stuff through the water is very difficult to overcome in a system that could only produce forces on the order of a tenth of a quarter-Newton--even if it could produce that torque.

I am always ready to be proven wrong...so when you build it, keep me posted on the progress.