| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a center takeoff type motor assisted power steering device capable of employing a layout in common with that of hydraulic type power steering devices, and preventing offset load from being applied to a rack shaft. SOLUTION: An electric motor 11 is arranged in a position which is away from the end part 2a of a rack shaft 2 in the direction of extension of the rack shaft 2, on the side far from a pinion 3. When a ball screw shaft 19 parallel to the rack shaft 2 is rotated-driven by the electric motor 11, a ball nut 20 is moved integrally with the rack shaft 2. Since the electric motor 11 is not placed on the rack shaft 2 or the pinion shaft, span L1 from a center position C across the width of the car body to the pinion 3, or span L2 from the end part 12a of an input shaft 12 to the rack shaft 2 is the same as that of hydraulic type power steering devices. Since the ball nut 20 fixed to the rack shaft 2 is to be engaged with the ball screw shaft 19 or a rack housing 4, torsion of the rack shaft 2 due to a tie rod 5 can be prevented.</p> |
