I changed the problem, because I understood my error I forgot a force. It's the same problem with one motor.
A motor drives two disks on a support. The support is turning clockwise at w1. Disks turn at w at start. The motor M gives a force F and a counterclockwise torque Fd/2 to the red disk. The motor M gives a force F and a counterclockwise torque Fd/2 to the magenta disk. The images shows rings but it's disks. There is friction at points A and B between disks, the force of friction is F/2.
1) Draw all forces
2) Calculate the torque on each disk
3) Calculate the torque on the support
The Attempt at a Solution
1) I drawn all forces:
I noted all forces but:
The color shows where goes the force, magenta -> to the magenta disk, red -> to the red disk, blue -> from the motor M to the support. Prime forces, like F4 -> F4' are forces that must be reported to the axis.
I'm not sure about my forces !
2) Each disk receives a torque +FR/2-F(R-d)/2=Fd/2 from other disk and -Fd/2 from a motor. So the torque on each disk is 0.
3) If my forces are correct there is no torque on the support from disks. But the motor gives a clockwise torque Fd/2, so the support receives a clockwise torque Fd.
Is it correct ?
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