| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing device with a sensor that can output a rotational state signal of high-resolution that is tolerant of external magnetic flux. SOLUTION: The bearing device comprises: a bearing 12 in which balls 20 are arranged between an inner ring 16 and an outer ring 18; a rotating member 22 supported by the inner ring 16; a cylindrical member 26 supported by the outer ring 18 and surrounding an outer peripheral surface of the rotating member 22; two pairs of detection coils 28 to 34 disposed on the cylindrical member 26; and a rotational state detector for detecting the rotational state of the rotating member 22 based on the output of each of the detector coils 28 to 34. The rotating member 22 is composed of a magnetic material, and a plurality of grooves 24 that extends in the axial direction are formed in the rotating member 22. A plurality of rows of windows 36 to 42 are formed in the cylindrical member 26, and the windows 36 to 42 of each row are surrounded by each of the corresponding detector coils 28 to 34. Differential signals are output from the detection coils 28 and 30 and the detection coils 32 and 34, the differential signals are converted into biphase signals in the rotational state detector, and an angle of the rotating member 22 is determined from that ratio. COPYRIGHT: (C)2008,JPO&INPIT
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