| 摘要 |
PROBLEM TO BE SOLVED: To lead the magnetic flux of a sufficient density and a direction appropriate to a magnetic response sensor for rectification control. SOLUTION: A supporting base body 26, provided with a series of magnetic response sensors 24, is mounted inside a housing 14H of a DC motor within a plane which is orthogonally crossed with the axis of a shaft 12S provided with magnets 22 for rectification. A ferromagnetic magnetic flux concentration member 30 roughly in a flat disk shape provided with an annular rim 32, provided with spokes 34 turned to the inner side of a radial direction is mounted to the supporting base body 26. Respective spokes 34 are provided with a clearance 36 in the radial direction, sensors 24 are housed in the clearance 36 in the radial direction, and the clearance 36 divides the spokes into two sections or forms a surrounding a recessed part provided with a side bar, extended along the side edge of the spoke. The magnetic flux concentration member 30 conducts the magnetic flux which originates from one pole to the respective sensors 24 and returns it to the other pole, so as to make the respective sensors 24 exposed to the effects of the magnetic flux originating from one of the magnets 22 for the rectification almost at all times, when the shaft is rotated. |
