| 摘要 |
1. Servo steering mechanism for an automotive vehicle, comprising : a fixed steering housing (10) containing a pinion (12) to be connected to an input control member (14) of the mechanism and cooperating with a rack structure (11) comprising means (70, 72) for connection to a linkage (73) of steerable wheels of the vehicle ; a fluid pressure servo assembly comprising at least one fixed piston (44) at the extremity of a piston rod (43) extending from one extremity (41) of a casing (40) mounted to the fixed housing, into the interior of the casing, and a movable cylinder (32) disposed coaxially within a portion of the cylindrical body of the rack (11) and delimiting with the piston (44) a pressure chamber communicating with a actuating valve means (20), characterized in that the rack structure is comprised of a rack body (11) slidingly guided in the steering housing (10), the cylinder (32) being mounted to the rack body (11) and comprising a portion extending coaxially beyond the rack body and having and external extremity (33) comprising a sealing ring (56) slidingly cooperating with the piston rod (43) to define with the piston an annular chamber (60), and in that the actuating valve means is a distributor valve means (20) actuatable by the input control member to admit selectively a pressure fluid in the one or the other of said chambers. |
