A modular bearing with internal piezoshunt damping

When a piezoelectric transducer is incorporated in a mechanical structure, it is possible to damp the structural vibrations of the base structure by passive energy dissipation in the electrical domain [1]. Due to the strong electromechanical coupling in piezoelectric elements, the mechanical energy can be efficiently converted to electrical energy. By shunting the piezoelectric element to a passive electric circuit, a part of the induced electrical energy can be dissipated. This principle is applied in a bearing to obtain noise and vibration reduction in rotating machinery. A ring-shaped module is developed with two perpendicular piezoelectric transducers, which can be mounted around a regular existing bearing. When the piezoelectric transducers are shunted to an appropriate electric impedance, damping will be introduced in the rotating machinery. Compared to an active solution, the increased robustness, the lower price and the ease of implementation are the main benefits of passive shunt damping.