| 摘要 |
In a ball nut type steering gear for a motor vehicle having two trains of balls confined within passageways formed by the helical grooves in a threaded shaft and a ball nut which surrounds the threaded shaft, two major diameter portions disposed in spaced-apart relation are formed in the threaded shaft. When the motor vehicle travels straight ahead, the balls are rollingly engaged in the helical grooves in the major diameter portions of the threaded shaft and the ball nut, and there is no play between the grooves and the balls which are engaged in the grooves. However, when the steering wheel is manipulated, the balls are rollingly engaged in the helical grooves in portions of the threaded shaft which are smaller in diameter than the major diameter portions of the threaded shaft, and there is play of a certain extent between the balls and the helical grooves. |
