Questions to ask yourself before you start :

What positioning do we want ?

A cylindrical recess with total immobilization.

What constraint tool can we use ?

Attachment
which makes the designated constraint elements coincide with complete immobilization (adjustable).
 

 Pre-position the bearing instances using the move tool .
 

 Select in the tree the constraint element of the axis (defined in the preparation phase) corresponding to the end circle of the axis, then while holding down the Ctrl key, select in the tree the constraint element of the first wheel instance corresponding to the circle of the wheel bore,  then apply the constraint.
 

 Proceed in the same way with the second instance of the wheel in order to constrain it to the other end of the axle.
Result

A recap video will be available at the end of this cycle.