| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a gear of a speed reduction mechanism generates a tooth hitting sound caused by backlash due to a road surface when a vehicle runs on a bad road, thereby generating noise, in an electric power steering system decelerating the rotation of an electric motor by the speed reduction mechanism and amplifying an output to perform torque assist. SOLUTION: An input shaft 3 and an output shaft 5 continuous to a steering wheel 2 are mutually connected through a first torsion bar 4. A pinion shaft 7 engaged with a rack bar 9 and the output shaft 5 are mutually connected through a second torsion bar 6. The transmission of vibration given to the pinion shaft 7 through wheels and the rack bar 9 to the output shaft 5 is suppressed. A tooth hitting sound between a worm shaft 15 and a worm wheel 16 can be suppressed. |
