Voice coil motor and direct-acting servo valve using the voice coil motor

摘要

A voice coil motor 2 using a Dual Halbach Magnet Array has an outer magnet array 5 and an inner magnet array 6, wherein the inner magnet array 6 comprises axially magnetized magnets 6A, 6C and 6E and radially magnetized magnets 6B and 6D. Each of the axially magnetized magnets 6A, 6C and 6E of an inner magnet array 6 is formed of a monolithic magnet having ring-shape, whereas each of the radially magnetized magnets 6B and 6D of the inner magnet array 6 is formed of a plurality of split magnets divided in a circumferential direction. A fixing means 13 is provided to fix the radially magnetized magnets 6B and 6D and the axially magnetized magnets 6A, 6C and 6E of the inner magnet array 6 in an axially clamped manner.