| 摘要 |
PROBLEM TO BE SOLVED: To provide a steering device for an automobile having a variable transmitting ratio mechanism with a simple structure at low cost, advantageous from a fail-safe point of view. SOLUTION: The variable transmitting ratio mechanism is provided between a steering wheel and a steering gear device. The variable transmitting ratio mechanism is composed of: a case 51; first and second bevel gears 511, 512 pivotally supported in the case 51 and engaged with each other; a rack gear 54 engaged with the bevel gear 512; a motor 52; and a ball screw mechanism 53 converting the rotation of the motor 52 to the parallel movement of the rack gear 54. The rotation of the steering wheel is inputted to the bevel gear 511, and the rotation of the case 51 is output to a steering dirigible road wheel side. The amount of the rotation of the steering wheel is output from an output shaft 510 being increased/decreased by the rotation of the motor 52. In case of the failure of the motor 52, the rotation of the steering wheel is hardly transmitted to the motor 52 due to the ball screw mechanism 53. COPYRIGHT: (C)2004,JPO |
