Patent ID: 7498700

Claim:
A linear drive system comprising: a pair of first and second opposing mobile units, a plurality of permanent magnets on the first mobile unit which are divided from each other in a stroke direction of the first mobile unit, one or more armature coils on the second mobile unit which face the permanent magnets, wherein, when an electric current is passed through the armature coils, an electromagnetic interaction between the armature coil current and magnetic fluxes of the permanent magnets produces a thrust force used for relative movement between the first and second mobile units, and a magnetic member on the second mobile unit in a position corresponding to either a maximum point or a vicinity of the maximum point of a magnetic force of the permanent magnets when the second mobile unit is in a neutral position, wherein a pair of flux loops passes through the magnetic member symmetrically in the center of the magnetic member, so that when the first and second mobile units move from the neutral position, the magnetic force of the permanent magnets acts in the stroke direction on the magnetic member.