Abstract: The portable abrasive tool comprises a flat motor composed of a rotor having a coil disk in the form of a disk on which multiple coil pieces are arranged in the circumferential direction about the output shaft when seen in the direction of the axis line of the output shaft and a stator having magnets arranged in the manner that the magnetic flux passes through the coil disk in the direction of the axis line of the output shaft, and an abrasive part connected to one end of the output shaft of the flat motor.

Abstract: A driving apparatus includes a first magnet, second magnet, stator, first coil, second coil, first bearing, second bearing and rotor. The first and second magnets respectively have a magnetized portion in which S pole and N pole are alternately magnetized. The rotor has a magnetic pole portion opposite to each magnetized portion. The stator fixes the first magnet and second magnet to the same axis to rotatably support the rotor. The first coil magnetically excites a portion where the magnetic pole portion of the rotor faces the first magnet. The second coil magnetically excites a portion where the magnetic pole portion of the rotor faces the second magnet. Thereby, a driving apparatus is provided which stabilizes the quality by simplifying the configuration of a rotor and makes it possible to realize high speed of rotation and improvement of response speed by decreasing the moment of inertia of a rotor.

Abstract: A stepper motor device has a stator and a rotor. The rotor comprises: a shaft; a rotor core associated with the shaft; and a magnet fixed to the rotor core. The stator comprises: a stator shell; a yoke disposed within the shell; a coil wound about the yoke and an end plate magnetically connecting the yoke to the stator shell. The coil is located beside the magnet in the axial direction of the motor. The stator has a number of salient poles, and the salient poles are arranged to face the magnet across a small air gap. The coil creates magnetic poles in the salient poles with a common polarity.

Abstract: An axial gap coreless motor includes a stator including a stator yoke having a surface and being composed of a plurality of laminated layers of silicon steel sheets secured together, a wiring substrate having a surface and being disposed on the stator yoke surface, and a plurality of coreless coils annularly disposed on the wiring substrate surface; and a rotor including a rotor magnet having a plurality of circumferentially arranged magnetic poles, wherein the rotor is rotated relative to the stator such that the rotor magnet axially confronts the coreless coil over an air gap.

Abstract: A driving apparatus includes a first magnet, second magnet, stator, first coil, second coil, first bearing, second bearing and rotor. The first and second magnets respectively have a magnetized portion in which S pole and N pole are alternately magnetized. The rotor has a magnetic pole portion opposite to each magnetized portion. The stator fixes the first magnet and second magnet to the same axis to rotatably support the rotor. The first coil magnetically excites a portion where the magnetic pole portion of the rotor faces the first magnet. The second coil magnetically excites a portion where the magnetic pole portion of the rotor faces the second magnet. Thereby, a driving apparatus is provided which stabilizes the quality by simplifying the configuration of a rotor and makes it possible to realize high speed of rotation and improvement of response speed by decreasing the moment of inertia of a rotor.