Patent ID: 6037680
Filing Date: 2000-03-14
Classification: G03F,H01J,H01L,H02K

Abstract:
A linear motor comprising:a single-phase coil;a plurality of polyphase coils each of which is shorter than said single-phase coil and wound to be parallel to said single-phase coil;a first permanent magnet movable relative to said single-phase coil and said plurality of polyphase coils in an axial direction of said single-phase coil;a first yoke consisting of a ferromagnetic substance and extending through said single-phase coil in the axial direction;a second yoke consisting of a ferromagnetic substance and having, outside said single-phase coil, a portion arranged to be parallel to said first yoke, to form a closed magnetic circuit together with said first yoke and said first permanent magnet such that said closed magnetic circuit circulates magnetic fluxes from said first permanent magnet across a winding of said single-phase coil; anda second permanent magnet for connecting said first and second yokes.