| 摘要 |
A steering shaft (3) is composed of an upper shaft (6), a lower shaft (7), an input shaft (8), and an output shaft (9). The upper shaft (6), the lower shaft (7), and the input shaft (8) can rotate together, and the input shaft (8) and the output shaft (8) are relatively rotatably coupled to each other via a torsion bar (11). The rotational position of a rotor (21) coupled to the output shaft (9) is calculated based on the detected rotational position of the lower shaft (7) and a steering torque detected based on the amount of relative rotational displacement of the input shaft (8) and the output shaft (9). Thus, it is not necessary to include a rotor rotational position detecting unit for detecting the rotational position of the rotor within the electric motor, which reduces the size of the electric motor.
|
