Patent ID: 7366636
Filing Date: 2008-04-29
Classification: B62D,G01D

Abstract:
1. A device for detecting rotational angle of a rotor, the device comprising: a main gear rotated integrally with the rotor and including an n number of teeth; a first detection gear including an m number of teeth engageable with the main gear and rotated together with the main gear; a second detection gear including an L number of teeth engageable with the main gear and rotated together with the main gear, wherein L is greater than m; a first detection means for detecting rotational angle α of the first detection gear within a cycle set in accordance with a predetermined angle; a second detection means for detecting rotational angle β of the second detection gear within the cycle; and a rotational angle calculating means for calculating a rotational angle θ of the rotor using the rotational angle α of the first detection gear within the cycle detected by the first detection means and the rotational angle β of the second detection gear within the cycle detected by the second detection means; wherein the rotational angle calculating means calculates a first rotational angle θ the rotational angle calculating means calculates a second rotational angle θ the rotational angle calculating means calculates the integer i indicating the number of cycles completed by the first detection gear in relation with the rotational angle α based on i=(θ the rotational angle calculating means calculates the rotational angle θ of the rotor based on θ=m/n×(α+iΩ) using the calculated integer i.