| 摘要 |
PURPOSE:To perform gear ratio change control with high reliability by coupling a ring gear rotating round a sun gear with an input shaft supporting a planet gear rotatably through a spring to constitute a set of planetary gearing mecha nism, and by installing a ring gear control means having a viscous clutch in continuity with this planetary gearing mechanism. CONSTITUTION:A steering gear ratio changing device according to the present invention consists of an input shaft 24 in continuity with a steering wheel 17, an output shaft 14a arranged coaxially therewith, a sun gear supported thereby, a ring gear 26 rotating round the sun gear 25, and a set of planetary gearing mechanism 21 consisting of a planet gear 29 meshing with the gears and supported by the input shaft 24 rotatably. Therein a C-spring 31 is installed to couple rotatably the ring gear 26 and the input shaft 24 supporting the planet gear 29 by giving a load with respect to the rotating direction. Thus a ring gear control means consisting of a viscous clutch 60, control pressure generating means 70, ring gear displacing means is installed in continuity to perform gear ratio change control. |
