System and method for detecting an axial position of a shaft
First Claim
1. A method for detecting a position of a shaft, the method comprising:
- providing a shaft comprising a hardened outer metallic layer having a first hardness level with a generally uniform radial depth;
forming a first strip extending in a generally longitudinal direction in the hardened outer metallic layer, the first strip having a second hardness level different from the first hardness level;
forming a second strip in the hardened outer metallic layer having the second hardness level, the first strip and the second strip spaced apart from each other over a longitudinal region;
sensing an angular difference between a first magnetic field associated with the first strip and a second magnetic field associated with the second strip; and
referencing an established relationship between a position of the shaft and the angular difference between the magnetic fields associated with the first strip and the second strip to detect a position of the shaft with respect to a reference point.
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Accused Products
Abstract
A shaft comprises a hardened outer metallic layer having a first hardness level with a generally uniform radial depth. A first strip extends in a generally longitudinal direction in the outer metallic layer. The first strip has a second hardness level different from the first hardness level. A second strip in the outer metallic layer has the second hardness level. The first strip and the second strip are spaced apart from each other over at least a longitudinal region. A sensor senses an angular difference between a first magnetic field associated with the first strip and a second magnetic field associated with the second strip. A data processor references an established relationship between a position of the shaft and the angular difference between magnetic fields associated with the first strip and the second strip to detect a position of the shaft with respect to a reference point.
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Citations
17 Claims
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1. A method for detecting a position of a shaft, the method comprising:
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providing a shaft comprising a hardened outer metallic layer having a first hardness level with a generally uniform radial depth; forming a first strip extending in a generally longitudinal direction in the hardened outer metallic layer, the first strip having a second hardness level different from the first hardness level; forming a second strip in the hardened outer metallic layer having the second hardness level, the first strip and the second strip spaced apart from each other over a longitudinal region; sensing an angular difference between a first magnetic field associated with the first strip and a second magnetic field associated with the second strip; and referencing an established relationship between a position of the shaft and the angular difference between the magnetic fields associated with the first strip and the second strip to detect a position of the shaft with respect to a reference point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A system for detecting a position of a shaft, the system comprising:
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a shaft comprising a hardened outer metallic layer having a first hardness level with a generally uniform radial depth; a first strip extending in a generally longitudinal direction in the hardened outer metallic layer, the first strip having a second hardness level different from the first hardness level; a second strip in the hardened outer metallic layer having the second hardness level, the first strip and the second strip spaced apart from each other over a longitudinal region; a sensor assembly for sensing an angular difference between a first magnetic field associated with the first strip and a second magnetic field associated with the second strip; and a data processor for referencing an established relationship between a position of the shaft and the angular difference between the magnetic fields associated with the first strip and the second strip to detect a position of the shaft with respect to a reference point. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification