| 摘要 |
<p>PURPOSE:To prevent the deterioration of the return of a handle by connecting an electric motor for generating assisting steering force to a steering system via a speed reduction mechanism for reducing the rotation of the electric motor and a clutch mechanism which is engaged only at the time of rotation of the electric motor. CONSTITUTION:When an electric motor 16 is started at a defined rotating speed, a driving shaft 24 is rotated via a speed reduction mechanism 18 and a rotor 33 is integrally rotated with the driving shaft 24. As the rotor 33 is rotated in a clutch case 20, a highly viscous oil sealed in a space part is forcedly moved between two faces in close proximity to each other by means of blades 34 due to the rotation of the rotor 33, generating an inner pressure proportionate to the rotating speed of the rotor 33 in the space part. This inner pressure acts on a pressurizing piston 31 frictionally engaging a clutch mechanism 17 in accordance with the inner pressure, to transmit the rotating torque of the electric motor to a pinion shaft 15.</p> |
