pic: Gerrish Gearbox MKII

[Tytus Gerrish]

ok Brandon, here is one of my better attempts at a gear, in this cace a helicial

[Madison]

Okay, I've played with real numbers for a bit today and I've come up with this very ugly, marginally useless spreadsheet of data. It's attached to this post.

Again, this is all based on the initial equation for a differential that I mentioned earlier in the thread, but reversed for the purposes of this design.

To recap., it's:

output = (inputA + inputB) / 2

This means, of course, that our differential's range of output RPM lies from 0 to ~12,500.

Within that range, there are three distinct spheres of operation.

• In the first, found from 0 to ~2100 (coded yellow) the Chiaphua motor alone is more powerful than the output of the differential.
• From ~2200 to ~8000 RPM (coded red), the differential offers more torque than either motor could provide individually at that RPM. At best, this is ~30% more powerful than the drill and ~90% more powerful than the chiaphua as it approaches its free speed.
• From ~8000 to ~12000 (coded green) and beyond, the drill motor alone provides more torque than the differential.

Out of curiosity, I also looked at what would happen if the drill output was geared down approximately 3.5:1 so that it better matched the Chiaphua's free speed of 5500 RPM.

This is what has me most confused, now. Using the same formula, it appears as if by gearing the drill motor down, the small range where there's a benefit to the system ceases to exist. In fact, in all cases, it appears that a drill motor geared down produces more torque on its own than if it were input into this differential with the chiaphua running at its output speed.

The data for that can be found on the far right. It makes no sense to me, so perhaps there's an error somewhere. Beyond that, the original green, yellow, and red colored data seems to corroborate what Joe Johnson and Andy Baker have said -- as if they need corroborating.

[Tytus Gerrish]

Thats Because you Havent Calcuated The Hrosepower yet!

[Jnadke]

Originally posted by Tytus Gerrish
The idea of this device is to have the motors work in harmony at any powre arc and while being slowed down wile pushing Where normel 2-motor gearboxes Fight themselves

Then you have already lost, because that's what this gearbox is actually designed to do. Such a design does give benefits over using 2 motors in a spur gear configuration, but if you implement it incorrectly, it will give you less benefits.

In using the output shafts as inputs, one shaft is designed to react off the other. This is why the stall torque of such a system is twice that of the weakest motor. Once the stronger motor attempts to exert more torque, it will overpower the weaker motor, causing it to have negative speed, as Joe mentioned.

Do not fool yourself into thinking such a design is exempt from the rules of a standard 2 motor drive system.

You seem to think that you can defy the laws of Physics with this gearbox. You cannot produce more output power than the sum of the individual motors.

[Madison]

Originally posted by Tytus Gerrish
Thats Because you Havent Calcuated The Hrosepower yet!

It doesn't matter. The relationships shown between torque and angular velocity across the three distinct ranges remain true when you're calculating the power output.

In the lower range, at approximately 1250 RPM, the Diff. outputs ~180 W of power. The Chiaphua, on the other hand, outputs ~ 225 W of power.

In the middle range, at approximately 4600 RPM, the Diff. outputs ~503 W of power. The drill outputs ~334 W and the Chiaphua outputs ~ 190 W. Again, this is in line with the expectations shown in my previous spreadsheet.

Finally, in the upper range, at approximately 10500 RPM, the Diff. outputs ~272 W of power. The drill? ~435 W. Again, in line with expectation.

However, despite having written all that, those numbers seem arbitrarily high. But, the relationships I've already established should remain true. Power is, after all, a function of both torque and angular velocity.

[Gadget470]

Tytus, what I think you may not be seeing is how torque is actually there. You seem to be referencing your animation a lot. And yes, the gearbox you've designed could feasibly work. Hopefully with the new nice gears (the one you've just shown) it can be easier for some of us to understand. Even if you animate it with perfect meshing, you still can't see how much torque is coming out of the final shaft.

Relax man, we are all testing it out, physically and mathematically. It's something new, it's gotta be picked apart before it's a) crap, b) awesome, c) another design.

Nobody said you are "destroying" energy, just.. misdirecting it somewhere that you don't want it to be.

When Motor A overpowers Motor B, causing B to stall, your gearbox is basically a normal bearbox reducing Motor A's RPM, but would be less efficiant because A would be also driving B.

Your rotational energy is lost, not destroyed. It's being disapated in noise, friction, and heat. And Motor B is pulling more amps, draining the battery faster.

As has been said, If implemented correctly, this could easily be a very good design.

[Tytus Gerrish]

KRipes! Ive been back on delphi for 3 days And Instead of hearing "Oh whatsup man Long time no see" You guys have to go out and say i am breaking laws Of Physics <LOOK! its JUST A MODEL KiNKS CAN BE WORKED OUT> im working on them all the time just be patient

[George1902]

Tytus: Please don't take offense to anything written here. Your idea has gotten the attention of quite a few people. They're all just thinking it through in their own ways to see if the concept can ever be a reality.

As for me, I get a headache when I look at it for too long. It's like one of those "Magic Eye" things.

(On a partially related note, 10 points to anyone who can trace this "Magic Eye" movie quote to it's movie:

"Oh, it's a sailboat."

"Brenda?"

"Jerk!")

[Ianworld]

Good thing i found this thread. I was about to try to build something like this without knowing the short comings.

From what i can tell though the real success of this type of drive would be where you put two drills( or another pair of motors) in conjuction.

Then drive one forwards at 100% power and drive the other in the other direction at 95% power. In a simplified system this would cause one to drive at its rated 19,470 rpm and another at 95% of that or 18500. The result combines these two rpms.

It would be 19,470 minus 18500 because that one is going backwards which results in a sense a negative rpm. This gives an rpm of about 1000 with twice the torque of the weaker motor or 190% of the torque of a drill motor. All the power with a 19.5 to 1 reduction.

you can then of course put both those motors driving forward at full power together to get about 40,000 rpm at full power with 200% torque. 40 times faster than the example i showed above. The problem of course then is finding ratios in the middle that work well by providing adequate rpm's and torque.

[edit] Hours later... I built a small differential out of legos and from what i can tell the first experiment is a failure. The torque appears to be much less when one is run backwards and rpm i subtracted from one motor. The result appears to be that it slowed down as predicted by adding the rpms together BUT the torque appears to have dwindled. Unfortunatly i don't have a way to measure the torque so i can't say how much.

[Gadget470]

Tytus, as I said in my post... we aren't saying you are breaking the laws of physics. The "lost" energy, isn't really lost. It's just not where you may want it (if implemented incorrectly).

By "Lost" we mean "Not going where we want it to be"


And for My 10 Points... the movie is "Mallrats"

[Ianworld]

okay i think i've found an answer? solution? complexity? idea?

Either way its called the torsen differential. The whole point of it is to overcome the limitation of only being able to supply 2 times the torque of the weaker motor. A torsen differential which is used on the Hummer allows the motor to supply up to 6 times more torque to one output shaft than to the other output shaft. The question i have though is what happens if we use it like these other differentials are thinking of being used?

here are some links about the torsen differential:

A white paper on the Torsen differential: http://www.sonic.net/garyg/zonc/Tech...ferential.html

and Howstuffworks.com's comments on the torsen: http://auto.howstuffworks.com/differential8.htm

[Tytus Gerrish]

ErrehhH! I need asprin....
Ill work it out!

But still In spite of its disadvantages it will Combine the force of two motors over a larger power arc than any ideas ive seen yet ,wich Work! but when theyre slowed down By puching Or accelarating They will not Be as efficent as My device

[FotoPlasma]

Originally posted by Tytus Gerrish
But still In spite of its disadvantages it will Combine the force of two motors over a larger power arc than any ideas ive seen yet ,wich Work! but when theyre slowed down By puching Or accelarating They will not Be as efficent as My device

Not that I want this not to work, but just out of curiosity, do you have any pieces of mathematical proof of your statements and assertions?

[Tytus Gerrish]

Originally posted by FotoPlasma
Not that I want this not to work, but just out of curiosity, do you have any pieces of mathematical proof of your statements and assertions?

Well, I dont have the numbers BUT!, why dont you ask the people who make Dual-engined Helicopters and helicoptor engines and the gearboxex that merge their power. ie, General Eletric, Sickorsky, Alison, Lycombing ,Textron, Etc....

Dont Get me wrong The constructive critisim is good But some of you can ,Realy Push it!

[Madison]

Originally posted by Tytus Gerrish
Well, I dont have the numbers BUT!, why dont you ask the people who make Dual-engined Helicopters and helicoptor engines and the gearboxex that merge their power. ie, General Eletric, Sickorsky, Alison, Lycombing ,Textron, Etc....

Dont Get me wrong The constructive critisim is good But some of you can ,Realy Push it!

I'd bet that those people did a lot of math and analyses of things before they ever set pen to paper, so to speak.

I'm not one to throw around praise of respect lightly and I think most people aren't. Show us something that proves this concept works, either through your own calculations or by those of someone else, and you'll earn more respect.

If you don't want people to offer suggestions, criticisms, or flat out tell you that your idea sucks, don't post it online. That's the nature of the internet. You've given nobody any reason to expect that your idea he has any worth.

I see a nice picture that copy-cats something you may have seen somewhere else. It shows no appreciation for the knowledge required to pull it off. Sure, there's a potential for it to evolve into something useful, but that potential is completely meaningless unless you're willing to harness and go to the next step. Making grammatically horrendous claims that we ought to trust you and that it will work is a waste of my time.

I'm not going to blindly praise you. Show me a real reason or leave me alone. A lot of the mentors here, me being in a different, lower realm entirely, work their behind off to make sure that their students have a real grasp of the concepts at work and that they're not making stuff up and getting lucky by it. It's insulting to them that you write off their contributions with your assumptions and crass attitude.