Steer-by-Wire Steering Damper With Variable Feedback Torque

The patent applies the dynamics principle by making the shear surface area between the rotor and stator variable rather than constant. As the steering wheel rotates, the overlapping area between the rotor shear surface and stator shear surface changes dynamically, causing the viscous damping torque to vary with steering angle. This dynamic variation accurately simulates the road feel characteristics that would be experienced in a mechanical steering system.

The patent implements parameter changes by varying the effective shear surface area parameter throughout the steering rotation range. The damping torque is directly proportional to the shear surface area, so by designing the rotor and stator with specific geometric profiles, the shear area parameter changes as a function of steering angle, thereby producing a feedback torque profile that accurately represents road conditions.

The patent achieves variable shear surface area through dynamic geometric configuration of the rotor and stator components. The rotor includes a shear surface with a specific profile, and the stator includes a corresponding shear surface, such that their overlapping area varies naturally as the rotor rotates relative to the stator. This dynamic interaction produces the desired variable feedback torque without requiring complex control mechanisms.

The patent replaces complex mechanical feedback mechanisms with a viscous damping system. Instead of using mechanical linkages or variable geometry mechanisms to adjust feedback torque, the invention uses the fluid dynamic properties of viscous damping fluid between variable-area shear surfaces. This substitution achieves accurate road feel simulation while maintaining relatively simple structural implementation.