AutoCAD Inventor :: Applying Sliding Connection For Wheel On Rail

I'm trying to apply the right constraint in stress analysis environment.

How would I apply the right constraint? And to which face of the wheel or axle should I apply the constraint to get right results.

If I'm applying the sliding connection to the face of the wheel in z direction, the model will stop stress analysis with an error of "not enough constraints"

if I apply the sliding constraint to the inside of the wheel on the surface of the circle, I get the result as attached. I get 0 reaction in the Z direction which is wrong and should be zero reaction in x direction. How do I get it right?

The correct way to me would be a constraint that would only take forces in the -Y direction, same direction as gravity.

The wheel should not have any other reaction than in the Y direction. Hoe do I define that constraint? In my model the wheel are free to rotate on the axle.

I'm attaching both the general arrangement and the reaction report.