Patent ID: 8995703
Filing Date: 2015-03-31
Classification: H02K,H04R

Abstract:
1. A permanent magnetic motor system for driving a loudspeaker voice coil, the permanent magnetic motor system having: a first part and a second part, wherein the first and second parts are spaced apart to define a volume between the first and second parts for receiving the voice coil, the voice coil being movable along a voice coil axis, the first and second parts each having at least one respective permanent magnet, wherein all permanent magnets contained within the first part and the second part are magnetised in a direction perpendicular to the voice coil axis, the permanent magnets having respective faces that face towards one another across the volume, the permanent magnets being arranged with opposite poles facing one another across the volume, such that lines of magnetic flux pass across the volume from the face of one permanent magnet to the face of the other permanent magnet, each permanent magnet having first and second sidewalls that extend in a direction away from the volume, and which form upper and lower faces of the permanent magnet when the system is oriented with the voice coil axis being vertical, wherein the first sidewall slopes towards the second sidewall in a direction away from the volume, the first and second parts each having a respective guide member for channelling lines of magnetic flux in a return path from one permanent magnet to the respective opposing permanent magnet of the other part, wherein the guide members are not permanent magnets.