| US 7,584,672 B2 | ||
| Magnetostrictive torque sensor | ||
| Song Ouyang, Hitachi (Japan); Yukio Ikeda, Hitachi (Japan); and Kouichi Sato, Hitachi (Japan) | ||
| Assigned to Hitachi Cable, Ltd., Tokyo (Japan) | ||
| Filed on Sep. 25, 2006, as Appl. No. 11/526,075. | ||
| Claims priority of application No. 2005-278244 (JP), filed on Sep. 26, 2005. | ||
| Prior Publication US 2007/0227268 A1, Oct. 04, 2007 | ||
| Int. Cl. G01L 3/00 (2006.01) | ||
| U.S. Cl. 73—862.331 | 19 Claims |
| 1. A magnetostrictive torque sensor, comprising:
a rotating shaft to rotate around a center axis, the rotating shaft comprising magnetostrictive characteristics;
a cylindrical magnetic core formed around said center axis at a predetermined distance from an outer periphery of the rotating
shaft;
a flexible substrate coil disposed on an entire inner periphery of the cylindrical magnetic core such that said flexible substrate
coil has a width in an axial direction that is equal to a width in the axial direction of said cylindrical magnetic core,
the flexible substrate coil comprising:
a first cylindrical detection coil layer formed on and occupying the entire inner periphery of the cylindrical magnetic core;
and
a second cylindrical detection coil layer formed on and occupying an entire inner periphery of said first cylindrical detection
coil layer such that said outer periphery of said rotating shaft is nearer to said second cylindrical detection coil layer
than said first cylindrical detection coil layer; and
a bridged circuit comprising said first and second cylindrical detection coil layers,
wherein a circumference of an outer surface of the flexible substrate coil and a circumference of an outer surface of the
first cylindrical detection coil layer is equal to a circumference of the entire inner periphery of the cylindrical magnetic
core.
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