Direct damping of an armature plate used in a spring-loaded brake

Objectives
In drive systems, spring-loaded brakes are commonly used to slow down, stop and lock the drive system. They are located at the B-side of electric motors. While braking, the armature plate is pressed against the rotating friction lining by spring elements. To release the brake, an electro magnet rescinds the spring forces. The fast movement of the armature plate leads to strong impacts with the friction lining and the housing of the electric motor. This results in a vibration of the brake-system and the emission of perceivable noise.

Procedure
Using the results of the AMFIDS-project, AM technologies have been used to integrate damping structures into the armature plate of a spring-loaded break. A segmented, ring shaped cavity was integrated into the armature plate consisting of eight single cavities. The powder was left inside the cavities to act as a particle damper. Further, lattice structures were integrated into the cavities to support the manufacturing process as well as to allow thinner walls. The cavity is divided into segments to achieve a better absorption of the impact forces. After manufacturing, the armature plat by laser melting process and a following turning operation experimental tests were carried out to evaluate the effect of the integrated damping structure. Therefore, the sound pressure level was measured and compared for the shift operation of the brake system.

Achievements
By integrating damping structures the mean sound pressure level could be reduced by 7.86 dB(C). This is a significant reduction in the emitted noise of the brake system and shows the tremendous potential of direct manufactured function integrated damping structures.