Fig. 1 shows the concept of Free Drive in Differential use.
A - input axle, C , C' - output axles.
Satellite A is input inner. Satellite B is outer . Dew to Cardan drive, B has two rotating axles B and A (C,C'). This allows output axle C rotate with not fixed speed = r(A) + r(B).
Where r(A) - B rotating around axle A, r(B) - B rotating around its own axle.
The band of transmission ratio A/B ÷ 1. Where A,B - number of teeth.
All wheels rotates independently to each other.
There is no sleeping effect.
No need in blocking.
No need in intermediate differential between front and rear axles
Fig. 2 shows Free Drive 1 without Cardan drive.
Fig. 3 shows another form of Free Drive.
Fig. 4 shows Free Drive 3 without Cardan drive.
Input and output can be replaced each other - Fig.5.
P.S. because the transmitting ratio is free it could be known in practice only. And maybe this Free Drive is something more
- CVT ?