Steering mechanism with planetary gear system and drive for impressing specific hand torque on the steering wheel
A motor vehicle steering mechanism is provided and includes a steering wheel fixedly connected to a steering column, a steering pinion meshing with a rack, a planetary gear system connected to the steering column and the steering pinion, wherein during a normal trouble-free driving operation the housing of the gear system is freely rotatable; an angle sensor detects the position of the steering column and/or steering wheel and generates a signal representative thereof, wherein a first drive applies torque directly to the steering column, and a second drive acts on the steering pinion or rack. The signal from the angle sensor is an input signal for an electronic control system that controls the second drive. A torque adjuster controls the first drive such that a hand torque corresponding to a driving situation is Produced for achieving a defined driving sensation for the driver on the steering wheel.
1. A motor vehicle steering mechanism, comprising:
a steering wheel fixedly connected to a steering column;
a steering pinion that meshes with a rack;
a planetary gear system having an input side connected to said steering column and an output side connected to said steering pinion, wherein said planetary gear system has a housing that during a normal trouble-free driving operation is freely rotatable;
an angle sensor for detecting the position of at least one of said steering column and said steering wheel and for generating a signal representative of such position;
a first drive for direct application of torque to said steering column;
a second drive for acting on said steering pinion or said rack;
an electronic control system for controlling said second drive, wherein the signal from said angle sensor is an input signal for said control system; and
a control means for controlling said first drive such that a hand torque corresponding to a driving situation is produced for achieving a defined driving sensation for a driver on said steering wheel.
2. A steering mechanism according to claim 1 , wherein a brake means is provided for effecting at least one of decelerating and stopping said housing of said planetary gear system.
3. A steering mechanism according to claim 1 , which includes means for positively or frictionally blocking a movement of said housing of said planetary gear system upon disruption of said first drive or of components associated therewith.
4. A steering mechanism according to claim 1 , which includes means for blocking a relative movement between said housing of said planetary gear system and said steering column, or between said housing and said steering pinion, upon disruption of said first drive or of components associated therewith.
5. A steering mechanism according to claim 1 , wherein a torque sensor M is provided for detecting a hand torque impressed upon said steering wheel and for generating a representative signal.
6. A steering mechanism according to claim 5 , wherein said control means is in the form of a torque adjuster that controls said first drive on the basis of at least one of said signal from said angle sensor and the signal from said torque sensor M.
7. A steering mechanism according to claim 6 , wherein further vehicle condition parameters form input quantities for said torque adjuster.
8. A steering mechanism according to claim 1 , wherein said first drive is a hollow shaft motor having a rotor that is fixedly connected with said steering column.
9. A steering mechanism according to claim 1 , wherein said first drive drives said steering column by means of least one of an intermediate gear mechanism and belts.
10. A steering mechanism according to claim 9 , wherein said belts are toothed belts.
11. A steering mechanism according to claim 1 , wherein a further redundant drive is provided for producing hand torque in the event of failure or malfunction of said first drive.