*As a newbie in physics I imagine this device and I would like to know why it can't increase its energy.*

**The device:**

I imagine 7 gears in rotation around blue axis in clockwise. Each gear has a mass $m$. In the same time, gears are turning at $w2$ around themselves. One clockwise next one counterclockwise like gears. But like I have 7 gears (odd number), 2 gears rotate in the same direction (2 red gears at bottom). I know 2 red gears at bottom can't turn like gears but I don't want gears but friction, it's possible to imagine a part of gear with rough surface only and study the device during a little while. So, between these gears I would like only friction. This friction give heating and forces $F1$ and $F2$, others gears give forces too, $F3$, $F4$ etc. I try to draw all forces but maybe I'm wrong. 

**G1 can have mass or not**

To draw forces, I'm starting from forces F1 and F2 and after I draw forces at right and at left in the same time, until I arrive at G1 (I'm not sure).

1/ G1 has mass. If energy is constant I can say that a torque on a gear is equal to the torque on blue axis. 

![enter image description here][1]

2/ G1 don't have mass. The same conclusion than 1/

![enter image description here][2]

3/ With 2 red disks only (not others gears), there is the same torque on disk, a torque on blue axis, but there is heating too. The heating seems to be an extra energy if I compare to 1/ and 2/

![enter image description here][3]

So, if in cases 1/ or 2/ the sum of energy can be constant, how it can be constant in the case 3/ ? 

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**The cycle is:** 

1. Friction is OFF. I launch gears at $w1$ and $w2$ without friction between red/red gears, this step need the energy $E$. 
2. I set friction ON between red/red gears  
3. I count all energies (heating too), $E$ must be constant. **I'm interesting about the transcient analysis** when there is friction between red/red gears. From time $t=0$ to $t=t_x$, **with $t_x$ very small**.


How $E$ could be constant?



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**Note:** 

I need to press 2 red gears at bottom for have friction, but I don't drawn these forces.

I guess no friction elsewhere than red/red gears surface. 

I don't believe in perpetuum mobile but I imagine devices, and like puzzles to resolve, I try to understand how the sum of energy is conserved, like that I learn physics in the same time. It's like a game for me.


  [1]: https://i.sstatic.net/1CPKB.png
  [2]: https://i.sstatic.net/Dn2uD.png
  [3]: https://i.sstatic.net/6qZCW.png