Patent ID: 7425783

Claim:
A linear motor comprising a stator portion having coil portions fixedly arranged in series in a moving direction and a mover portion having one or more magnets and combined so as to be movable in said moving direction due to interaction with magnetic flux generated with said coil portions, said linear motor characterized in that said stator portion has, as said coil portions, coil portions of N phases (N is an integer of 3 or more) to be fed with currents having a phase difference from one another, the coil portion of each phase has, as each pair, a first coil wound clockwise and a second coil wound counterclockwise, wherein said first and second coils in each pair are arranged adjacent to each other in the moving direction and connected in series and the plurality of pairs of said first and second coils are arrayed in the moving direction, and further, an extending length of said first coil and said second coil is set to 360 degrees, wherein the coil portion of the second phase is disposed so as to shift in the moving direction by (360/N) degrees with respect to the coil portion of the first phase, the coil portion of the third phase is disposed so as to shift in the moving direction by (360/N) degrees with respect to the coil portion of the second phase, and the coil portion of the N-th phase is disposed so as to shift in the moving direction by (360/N) degrees with respect to the coil portion of the (N−1)-th phase, said coil portions of the N phases being disposed so as to be layered together, said magnet is combined with said coil portions of the N phases and a length of said magnet in the moving direction is set to half or less of a wavelength of magnetic flux generated with said coils, and a first magnetoelectric conversion element is attached to said mover portion at a position away from the center of said magnet in the moving direction by a predetermined distance and the currents to said respective coil portions are controlled based on an output of said first magnetoelectric conversion element.