| 摘要 |
<p>PROBLEM TO BE SOLVED: To freely rotate a steering wheel even when an electric motor and/or a steering control system is broken down by using a small-sized and lightweight clutch having a simple structure. SOLUTION: In this electric power steering device 10, the clutch 40 permitting only transmission of turning effort from the electric motor 20 to a power transmission device 21 is provided between the electric motor 20 and the power transmission device 21. The clutch 40 is provided with a driving plate 41 integrally rotating with the electric motor 20, a driven plate 43 integrally rotating with the power transmission device 21, and an intermediate plate 42 placed between the driving plate 41 and the driven plate 43 and capable of being displaced to axial direction. A ball 53 is provided between ball pressing and holding surfaces 51A and 52A of the driving plate 41 and the intermediate plate 42 facing to each other. A distance between the ball pressing and holding surfaces 51A and 52A is brought closer toward outside along radial direction. A ball abutting part 51B abutting onto the ball 53 along rotational direction of the driving plate 41 is formed on the ball pressing and holding surface 51A of the driving plate 41.</p> |
