ELECTRODYNAMIC HEAD WITH NANODISPERSED MAGNETIC LIQUID Russian patent published in 2010 - IPC H04R9/06 

FIELD: physics.

SUBSTANCE: electrodynamic head has a diffuser holder, a diffuser, a speech coil, a magnetic system consisting of a permanent magnet, two flanges, a core and a working gap filled with nanodispersed magnetic liquid. The edges of the core and flange are rounded. The surfaces of the core and flange in contact with the nanodispersed magnetic liquid have a non-magnetic electroconductive coating. On the surface of the core there is an annular groove at a distance from the core which is equal to the width of the flange. There is a short-circuited ring in the groove which is made from high-electroconductivity material. The shape of the cross-section of the short-circuited ring coincides with the shape of the cross-section of the annular groove of the core. The outer surface of the ring is on the same level as the surface of the non-magnetic electroconductive coating of the core, and on the surface of components which form the inner cavity of the magnetic system, core, flanges and permanent magnet there is an electroconductive coating.

EFFECT: high reliability and longer service life of the dynamic head, increased power with preservation of overall dimensions and reduced distortions.

8 cl, 5 dwg