Electric steering actuator

摘要

In an electric steering actuator comprising an electric motor having a hollow output shaft, a steering shaft passed through the hollow center of the output shaft of the electric motor, and a ball-screw mechanism provided between the output shaft and the steering shaft for converting the rotary movement of the output shaft into a longitudinal movement of the steering shaft, a rotation preventing mechanism is provided for preventing the rotation of the steering shaft around its axial line. The rotation preventing mechanism comprises a guide pin extending in the casing in parallel with the axial line of the steering shaft, and a fork member engaging the guide pin between two prongs thereof. Because the rotation preventing mechanism can be formed by using a guide pin made of a stock steel or other metallic member, such as a cold finished steel bar, the manufacturing cost can be reduced. Furthermore by using a fork member defining an open slot for engagement with the guide pin, the assembling process is simplified, thereby reducing the manufacturing cost. In particular, by interposing a plastic slider between the pin and the fork member, metallic noises are avoided, and a smooth operation is ensured at a low cost.