Rolls-Royce unveiled the latest addition to its range of marine thrusters[ds_preview], with the launch of a new azimuth thruster powered by permanent magnet (PM) technology. The launch followed a programme of sea trials in which a pair of thrusters demonstrated efficiency savings of 7–13% depending on ship speed, and in comparison to azimuth thrusters powered by a conventional diesel-electric system. According to Helge Gjerde, Senior Vice President for Propulsion/Commercial Marine, other benefits include more power through a propeller of the same diameter, reduced noise and vibration, and scope to remove and maintain PM thrusters without the need for a dry-docking.
The permanent magnet motor consists of two main parts – a stator that carries a number of electrical coil windings, and a rotor fitted with a number of very strong permanent magnets. A rotating magnetic field is created by the stator which interacts with the fields of the permanent magnets on the rotor, which generates force to drag the rotor around, providing the mechanical power.
