Ball screw for electromechanical steering system of vehicle, has threaded spindle comprising helical ball tracks at outer circumference, and balls that are in contact with ball tracks, where ball tracks have variable thread pitch

摘要

The ball screw has a ball nut (1), and balls (3) guided at the ball nut. A threaded spindle (2) comprises helical ball tracks (4, 5) at an outer circumference, where the threaded spindle is a section of a steering rod. The balls are in contact with the ball tracks. The ball tracks have variable thread pitch and uniform slope characteristic. The balls are provided between roles (6), which are rotatably mounted at pins (7) in the ball nut. The roles have a profile adapted to spherical shape. An axis of rotation of the roles runs parallel to a longitudinal axis of the threaded spindle.