Patent ID: 7677122

Claim:
A steering angle sensor assembly for a vehicle, comprising: a rotary plate that is provided between a steering wheel and a steering column and rotated together with the steering wheel by rotating the steering wheel; a planetary gear train comprising a plurality of planetary gears disposed on an inscribed surface of the rotary plate, the planetary gears having diameters different from each other, the planetary gears being rotatably supported by supporting pins, and the planetary gears meshing with a sun gear formed on an inner periphery of the rotary plate; a circuit board that is provided to correspond to the inscribed surface of the rotary plate and covers the planetary gear train while the supporting pins pass through the circuit board, the circuit board detecting measurement signals used to calculate an absolute angle of the steering wheel on the basis of the intensity of a magnetic force corresponding to the rotation of the planetary gear train, processing the measurement signals, and transmitting the processed measurement values to an ECU; and a cover that is provided toward the steering column, the circuit board being fixed to an inner surface of the cover and the rotary plate being rotatably provided to the cover, wherein the rotary plate is formed as a first ring plate encompassing one side of the circuit board and the planetary gear train, the rotary plate, having at a center portion, an inner circular pipe portion that protrudes toward the cover, wherein the cover is formed as a second ring plate encompassing another side of the circuit board and a planetary gear train, the cover having at, a circumferential portion, an outer circular pipe portion that protrudes toward the rotary plate, and wherein the circuit board and the planetary gear train are positioned within an arc shaped space defined between the inner circular pipe portion and the outer circular pipe portion.