| 摘要 |
PROBLEM TO BE SOLVED: To provide a torque detector capable of restraining detection errors of a torque from being generated, caused by moisture absorption in a magnetic ring, and of detecting accurate torque. SOLUTION: An outer circumferential face of the second magnetic ring 5 of a green compact, comprising a powdery magnetic material, is coated with a moisture-proof layer 54 of a nonmagnetic substance using a thermal shrinkage tube. The second hygroscopic magnetic ring 5 is thereby restrained from absorbing moisture, and the detection errors of the torque are restrained from being generated caused by moisture absorption of the magnetic ring 5. The moisture-proof layer 54 is independent of an impedance change of the first excitation coil 7, because the moisture-proof layer 54 is the nonmagnetic substance. As a result, the accurate torques applied onto the first and second rotary shafts 2, 3 are detected by a magnetic circuit, constituted of the first and second magnetic rings 4, 5 and the first excitation coil 7. That is, reliability is enhanced in the torque detector A. COPYRIGHT: (C)2008,JPO&INPIT
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