| 摘要 |
<p>The invention relates to a power-assisted steering device for a vehicle, of the kind comprising a steering wheel and steering column coupled to a steering device such as a rack and pinion arrangement, the auxiliary assisting means being hydraulically operated and including a hydraulic cylinder acting on the rack. The steering column comprises two parts which are capable of limited angular displacement in response to steering movements, and the assisting device has a fluid distributor which is sensitive to this angular displacement. This distributor comprises an axially-stacked assembly having a first stator, a first rotor plate integral in rotation with one of the two parts of the steering column, a second rotor plate integral in rotation with the other part of the steering column, and a second stator, the rotor plates having a series of hydraulic passages for feed and return of the pressurized hydraulic fluid. In order to eliminate or reduce axial thrust of the plates and stators resulting from pressure differentials occurring during operation, according to the invention at least one pressure balancing or equilibration channel is provided in at least one of the rotors. This eliminates the need for thrust bearings in the assembly and thereby reduces the cost of the device.</p> |
