Device for measuring rotational speed using an optical fiber sensor
First Claim
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1. A device for measuring the rotational speed of a shaft coupled to a toothed wheel that is rotationally driven by the shaft comprising:
- a magnet being placed in the vicinity of the toothed wheel, an optic fiber having two ends and a central portion, one of the ends being connected to a light source, the other end being connected to light analysis means, the central portion being supported by a magnetostrictive material located in a magnetic field produced by the magnet said optic fiber being subjected to stresses generated by a said magnetostrictive material in response to said magnetic field.
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Abstract
A device for measuring the rotational speed of a shaft. A toothed wheel is connected to rotate with the shaft within a magnetic field. A birefringement optic fiber is connected to a light source, and passes through the magnetic field. A magnetorestrictive material is supported in contact with the optical fiber and produces stress on the optical fiber in response to magnetic flux variations. Light emerging from the optical fiber is analyzed with respect to its change in phase to determine the periodic variation in the magnetic field caused by the toothed wheel.
27 Citations
26 Claims
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1. A device for measuring the rotational speed of a shaft coupled to a toothed wheel that is rotationally driven by the shaft comprising:
- a magnet being placed in the vicinity of the toothed wheel, an optic fiber having two ends and a central portion, one of the ends being connected to a light source, the other end being connected to light analysis means, the central portion being supported by a magnetostrictive material located in a magnetic field produced by the magnet said optic fiber being subjected to stresses generated by a said magnetostrictive material in response to said magnetic field.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A device for measuring the rotational speed of a shaft coupled to a toothed wheel which rotates within a magnetic field comprising:
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a light source; a birefringement optic fiber connected at one end to said light source extending through said magnetic field; a magnetostrictive material supported in contact with said optical fiber for producing stresses in said optical fiber in response to magnetic flux variations induced in said magnetic field by said toothed wheel; and means for analyzing connected to a remaining end of said optic fiber for measuring changes in phase of said light in response to changes in stress applied to said optic fiber. - View Dependent Claims (23, 24, 25, 26)
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Specification