CHAPTER 3 - PART 2 - CHASSIS - STEERING MECHANISM

The steering mechanism allows the motor vehicle's direction of travel to be changed by adjusting the angle of the steered wheels. In cars, these are usually the front wheels, which turn to the left or right when the driver turns the steering wheel. During a turn, each wheel follows a different path, but all these paths share the same centre, called the turning centre.

In modern motor vehicles, the steering system often uses hydraulic, electrohydraulic or electric assistance to reduce the effort required to turn the steering wheel. In electric power steering systems, the assistance force is controlled electronically and can vary according to the motor vehicle's speed and driving conditions.

Components of the steering mechanism:

• steering wheel: is mounted on the steering column and allows the driver of the motor vehicle to control its direction of travel. The steering wheel's rotational motion is transmitted through the steering column to the steering gear. In the steering gear, this motion is converted into lateral movement of the rack, to the left or right. Tie rods are fitted at the ends of the rack and transmit motion to the wheels through the steering knuckles;

• steering column: transmits the steering wheel's rotational motion to the steering gear. It includes:
  • steering shaft: the rotating component of the steering column, which may incorporate one or two universal joints, depending on the design;
  • mounting system: secures the steering column to the body and allows the shaft to rotate in bearings;

• steering gear: is one of the main components of the steering system. It converts the rotational motion transmitted by the steering shaft into linear motion to the left or right through the toothed rack;
• tie rods: are connecting links that transmit motion from the steering gear to the components that turn the steered wheels.