Low stresses but enormous displacements

Hi,

I am currently trying to Simulate a Wheelhub for a Formula Student Car in Altair Hyperworks. But the Problem is that my Analysis shows Stresses of around 140 MPa which is totally acceptable for Aluminum but the Displacement has a Value of 1-4 Kilometers. 

The Wheelhub is constrained with Rigid-Elements on the Surfaces for the Bearings. These are Connected to Constraints allowing movement in the Moment-Directions and on one Bearing in the Y-Direction. The Rigids have no dof.

When I locked all dof´s on the constraints and allowed the movements in the Rigid-Elements, the Displacement became realistic. But the Results should be the same in both Cases or am I getting this wrong? 

Or is there any other Reason why the Displacement reaches these High-Values?