Ball screw thread shoot integrated electromechanical steering-unit for motor car, has ball recirculation device provided at nut, where number of balls is aligned on length of ball travel path according to partial filling coefficient

摘要

The steering-unit has a ball screw thread shoot comprising a ball screw (1) that is engaged with a ball circulating nut (2) over balls. A ball recirculation device (6) is provided at the ball circulating nut for interconnecting end regions of a ball track space, so that a circulation of balls (5) is carried-out along a ball travel path that passes through the ball track space and the ball recirculation device. A number of balls of a ball-filling is aligned on length of the ball travel path according to a partial filling coefficient whose value lies in a range between 0.8 and 0.95.