Hydraulic seal and piston rod guide.

摘要

An automotive power steering unit (10) has a shaft guiding and sealing assembly which includes a guide bushing (30) received within the open end (21) of a cylinder (12) with an inside surface (35) forming a close fit with the piston rod (15) to provide guidance and support for the rod. An annular seal (50) is carried on an inner end of the bushing (30) within the cylinder and has an outer static sealing lip (62) which engages the cylinder wall and an inner dynamic portion (58) which engages the rod (15). A portion of the bushing forms an anti-extrusion backing wall (55) which supports the seal from excessive bending under hydraulic pressure. A retainer snap ring (40) retains the bushing in place and supports the bushing against dislodgment by reason of force impact of the tie rod ball housing against the bushing in one extreme steering lock position of the steering mechanism.