Magnetostrictive drive module.

摘要

The drive modules (10) of a magnetostrictive transducer are fabricated from interleaved permanent magnet disks (2) (samarium cobalt) and high-strain, low-permeability magnetostrictive lanthanide alloy (Terfenol-D) disks (1) to form a stack (11) of such interleaved materials of substantially uniform magnetic field distribution in the stack. Two such stacks (11) in side-by-side relationship provide a series-aiding magnetic circuit completed through high-permeability flux return pole pieces (4) at their ends thereby providing a substantially uniform magnetic field distribution in the stack (11). Each stack (11) has longitudinally-extending and electrically-insulated planar cuts and each flux return pole piece (4) is a laminate of thin sheets of high-permeability electrically-insulated steel to reduce eddy current losses resulting from the AC field. The steel sheets are constrained by a nonmagnetic end-block (5) into which the steel sheets are inserted and bonded. AC coils (3) surround the stacks (11) to provide the AC field.