Power steering device for automotive vehicles

摘要

An oil hydraulic power steering device of the rack and pinion type which includes a rack rod supported for lateral oscillation about a fulcrum adjacent one end thereof and a power actuator comprised of a piston secured to the rack rod, an outer cylinder, and an inner cylinder in which the piston is slidably fitted and which is floatingly supported in the outer cylinder. The device further includes a spring for normally biasing the rack rod against the pinion and a mechanism for engaging the normally free end of the rack rod while laterally displacing the rod end to increase the backlash in the rack and pinion gearing as the rack rod approaches the end of its stroke. There is no excessive pressure of contact occurring between the meshing gear teeth and the backlash is self-adjustable as the teeth wear down. The inner cylinder of the actuator is laterally movable to follow the rack rod when the latter is forced to bend while maintaining the concentric relation to the rack rod to enable the latter at all times to operate smoothly.