| 摘要 |
<p>PURPOSE: To impede axial movement of a driving shaft so as to positively prevent generation of noise by imparting pre-load to both rolling bearings for supporting the driving shaft, from the axial direction by a pre-load imparting member. CONSTITUTION: Steering torque generated by a steering wheel is transmitted to a pinion by a steering shaft 3, and a rack meshed with this pinion is axially moved to change a wheel steering angle. A worm 9 and a worm wheel 10 are provided in order to transmit torque of a steering assist force generating motor 8 to the steering shaft 3. A driving shaft 50 rotated by the motor 8 is supported by a pair of rolling bearings 62, 63, but in this case, an annular pre-load imparting part 65 surrounding the driving shaft 50 and having an external thread part 65a formed at the periphery is interposed between the motor 8 and the bearing 63 on the motor 8 side. Pre-load is thereby imparted to both bearings 62, 63 from the axial direction so as to eliminate axial movement of the driving shaft 50.</p> |
