| 摘要 |
PURPOSE:To make a transmission auxiliary member and a final step reduction gear easily separable at the time of trouble happening in a driving source, by inserting a shear pin into an interval between a pin hole installed in the final step reduction gear of a reduction gear mechanism to be combinedly connected to the driving source in a power steering and another pin hole installed in the steering force transmission auxiliary member. CONSTITUTION:At the time of normal steering, when a steering wheel is rotated, a power assist corresponding to detecting output of a torque sensor detecting the torque given to a steering shaft is given to this steering shaft from a motor 21 via a pinion gear 32, a reduction gear 25, a final step reduction gear 26 and a yoke 30 of a universal joint. On the other hand, when a burnout in the motor 21 or an engagement failure in gears, etc., is produced and manual steering force increases, shearing force to be added to a shear pin 28 grows larger. And, when this shearing force becomes more than the specified value, this shear pin 28 is cut off, whereby mechanical transmission between a steering force transmission auxiliary member 27 and the final step reduction gear 26 is intercepted, thus the steering shaft is made rotatable by hand. |
