Patent ID: 9685850
Date: 2017-06-20
CPC Classifications: F16K,H02K

Claim:
1. A voice coil motor comprising: an outer magnet array constructed by arranging radially magnetized magnets of ring-shape and axially magnetized magnets of ring-shape to be axially adjacent to each other in a manner that magnetic poles of the radially magnetized magnets and the axially magnetized magnets are altered by substantially 90 degrees in a cross-section including a center axis of the outer magnet array; an inner magnet array constructed by arranging radially magnetized magnets of ring-shape and axially magnetized magnets of ring-shape to be axially adjacent to each other, the radially magnetized magnets having magnetic poles which are directed in the same directions as those of the outer magnet array, and the axially magnetized magnets having magnetic poles which are directed in directions opposite to those of the outer magnet array; an outer cylindrical member for supporting an outer periphery of the outer magnet array; an inner cylindrical member for supporting an inner periphery of the inner magnet array; a side member for connecting at least one axial end of the outer cylindrical member and that of the inner cylindrical member; and a coil arranged axially movably in an annular space between the outer magnet array and the inner magnet array to be actuated axially when current is supplied to the coil, wherein each of the axially magnetized magnets of the inner magnet array is formed of a monolithic magnet having ring-shape, wherein each of the radially magnetized magnets of the inner magnet array is formed of a plurality of split magnets divided in a circumferential direction, wherein a fixing means is provided to fix the radially magnetized magnets and the axially magnetized magnets of the inner magnet array in an axially clamped manner, and wherein the voice coil motor further comprises a non-magnetic tube which continuously surrounds outer peripheries of the radially magnetized magnets and the axially magnetized magnets of the inner magnet array.