Rare Earth Magnet Basics / Glossary of Magnet Terms / VCMs (Voice Coil Motors)
- VCMs (Voice Coil Motors)
- Original, voice coil motor referred to the linear actuators that drive the coils of speakers, but recently the motors for driving hard disk drive (HDD) heads are also called voice coil motors. Voice coil motors for hard disk drives usually have a structure that places a coil between two magnet sheets and drive the suspension arm with the force generated by the magnetic field and the current flowing in the coil. The detection head is mounted on the suspension arm. (See the page with the magnet application examples.) One or two neodymium rare earth magnet sheets are used in voice coil motors for various hard disk drives. With recent hard disk drive size reductions, voice coil motors themselves are becoming smaller, so stronger yet smaller rare earth magnets are required.
