How to properly create rotation

Hi Everyone,

my project is to model a planetary ball mill, and I have some big problem with the rotation of the disk and cylinders. 

These elements should rotate in the opposite direction (as in the picture); however, if the speeds of the disk and cylinders are close to each other, the movement of the cylinders slows down or stops altogether. 
This problem does not occur when I change the rotation to the same direction. I think there's something wrong with the reference system but I can't find the error.

I will be grateful for help.

Iwona