Torque sensor assembling method, torque sensor and electric power steering device

A torque sensor comprising;

• a torsion bar rotationally disposed in a housing;
• a first outer coil portion fixed at the housing;
• a second outer coil portion fixed at the housing;
• a first inner coil portion fixed at the torsion bar;
• a second inner coil portion fixed at the torsion bar;
• a first resolver having the first outer coil portion and the first inner coil portion and fixed at one end side of the torsion bar, the first resolver adjusted to detect a rotational angle of the torsion bar based upon a change of a mutual inductance between the first outer coil portion and the first inner coil portion;
• and
• a second resolver having the second outer coil portion and the second outer coil portion and fixed at an other end side of the torsion bar, the second resolver adjusted to detect a rotational angle of the torsion bar based upon a change of a mutual inductance between the second outer coil portion and the second inner coil portion,
• wherein an angle difference between a circumferential directional angle of the first outer coil portion and a circumferential directional angle of the second outer coil portion is substantially equivalent to an angle difference between a circumferential directional angle of the first inner coil portion and a circumferential directional angle of the second inner coil portion such that a torque applied to the torsion bar is detected based upon a difference between the angle detected by the first resolver and the angle detected by the second resolver.

An electric power steering device provided with a torque sensor assembled by a method including the steps of:

• fixing a first inner coil portion at one end side of a torsion bar, the first inner coil portion being rotatable with the torsion bar;
• fixing a second inner coil portion at an other end side of the torsion bar, the second inner coil portion being rotatable with the torsion bar;
• measuring an angle difference between a circumferential directional angle of the first inner coil portion and a circumferential directional angle of the second inner coil portion;
• fixing a first outer coil portion and a second outer coil portion, of which circumferential angle difference is substantially equivalent to the measured angle difference between the first inner coil portion and the second inner coil portion, at a housing;
• and
• rotatably disposing the torsion bar fixed with the first inner coil portion and the second inner coil portion in the housing, characterized in that the torque sensor is
• connected to a steering shaft rotated in response to an operation of a steering wheel.

An electric power steering device provided with a torque sensor including:

• a torsion bar rotationally disposed in a housing;
• a first outer coil portion fixed at the housing;
• a second outer coil portion fixed at the housing;
• a first inner coil portion fixed at the torsion bar;
• a second inner coil portion fixed at the torsion bar;
• a first resolver having the first outer coil portion and the first inner coil portion and fixed at one end side of the torsion bar, the first resolver adjusted to detect a rotational angle of the torsion bar based upon a change of a mutual inductance between the first outer coil portion and the first inner coil portion;
• and
• a second resolver having the second outer coil portion and the second outer coil portion and fixed at an other end side of the torsion bar, the second resolver adjusted to detect a rotational angle of the torsion bar based upon a change of a mutual inductance between the second outer coil portion and the second inner coil portion,
• wherein an angle difference between a circumferential directional angle of the first outer coil portion and a circumferential directional angle of the second outer coil portion is substantially equivalent to an angle difference between a circumferential directional angle of the first inner coil portion and a circumferential directional angle of the second inner coil portion such that a torque applied to the torsion bar is detected based upon a difference between the angle detected by the first resolver and the angle detected by the second resolver, characterized in that the torque sensor is connected to a steering shaft rotated in response to an operation of a steering wheel.