Voice coil motor

Abstract

Abstract PURPOSE:To remove the variation of an output based on leakage flux by connecting a center pole and one end of a yoke surrounding the center pole with a rear yoke and mounting an auxiliary yoke in a space formed by a permanent magnet fitted at the other end of the yoke. CONSTITUTION:A ring 2 made of copper or aluminum having low permeability is fixed around a center pole 1 consisting of a bar-shaped ferromagnetic substance. One end of the center pole 1 and one end of a yoke 3 composed of a ferromagnetic substance surrounding the periphery of the center pole 1 are connected by a rear yoke 4 consisting of the ferromagnetic substance to constitute a core, and a permanent magnet 5 is mounted on the inside of the other end of the yoke 3 to shape a pole air gap 6. An auxiliary yoke 8 composed of the ferromagnetic substance is connected to the rear yoke 4, and an auxiliary ring 9 having low permeability consisting of copper, aluminum or the like is disposed on the center pole 1 side. A movable coil 7 in length larger than the length of the air gap is arrange in the pole air gap 6. Accordingly, leakage flux on the inside and outside of the pole air gap section 6 is equalized, thus removing the nonuniformity of generating force by the position of the coil 7, then shortening the positioning time.

Inventors

• 👤 Kenji Edakawa
• 👤 枝川　憲二

Bibliographic Details