an angle of lt 90 u00b0 with respect to the rotation axis 19 the disk shaped ring 23 ends in a second sleeve portion 24 whereby the sleeve portions 20 24 extend in parallel relationship to the rotation axis 19 but in opposite axial directions as shown in fig1 and 3 the half shells 2 3 are so interconnected that the sleeve portion 14 of the half shell 2 embraces with its outer surface area the sleeve portion 20 of the half shell 3 and the sleeve portion 18 of the half shell 2 embraces with its outer surface area the sleeve portion 24 of the half shell 3 an inwardly turned flange 25 of the sleeve portion 24 surrounds the sleeve portion 18 of the half shell 2 to thereby ensure the integrity of the interconnection of the half shells 2 3 when assembled together the half shells 2 3 confine a ring shaped interior space 28 for receiving a plurality of rolling bodies such as ball members 11 thus in the event the grinding wheel 6 has an imbalance e g an imbalance 10 at an upper circumferential position of the grinding wheel 6 as shown in fig1 the ball members 11 tend automatically to travel to a position which is opposite to the imbalance 10 as depicted in fig1 and 2 as viewed in radial direction from inside to outside the interior space 28 expands in axial direction as a consequence of the slanted transition 22 this is advantageous during assembly of the compensation disk 1 as damping fluid such as oil will not leak and is safely retained in the formed depression of the ring shaped interior space 28 in addition the ball.