The steering system is one of the essential operating devices of the car. Here, modern steering systems enable precise changes in direction while driving or maneuvering. In this article, you will learn how the steering system in the car is structured and how it works. You will also get an overview of the different steering parts.

The car’s steering system – structure and design

In the car, the steering system influences the direction of travel and makes the use of the vehicle possible in the first place. In addition to the desired change of direction, the steering system in the car today must meet many other requirements. The steering systems installed have therefore been continuously perfected and adapted to new requirements throughout the history of automotive engineering, including not only a precise change of direction but also good directional stability of the front wheels. The steering system’s smoothness also increases comfort. However, the principle of the steering system has changed little over the decades. The change in direction is still determined by the turning of the wheels on the steering axle.

Structure of the steering system in a car

In cars, the steering axle is usually located at the front of the vehicle. Here, the steering acts exclusively on the front wheels, through which the steering angle of the vehicle is determined. Only a few vehicles also have steered wheels on the rear axle to improve driving dynamics. The driver determines where the car is headed by turning the steering wheel. The steering wheel is firmly connected to the steering column, which makes positive contact with the steering gear. The only difference is in vehicles with steer-by-wire technology. Here, the steering column is only connected to the transmission if the electric steering fails.

The modern rack-and-pinion steering system

Almost all modern passenger cars today have rack-and-pinion steering. At the heart of this type of steering is a steering gear with special technology. A steering pinion connected to the steering column engages a rack that moves over the steering wheel when the column is turned. Other types of steering are rarely used in today’s cars. One exception is off-road vehicles, which require particularly robust components and steering arms. Steering systems with spindles or recirculating ball steering systems are also still sometimes found in classic cars.

Hydraulic power steering in passenger cars

Nowadays, almost every newly built car has power steering. This type of steering simplifies steering at low speeds and when maneuvering the vehicle. The wheels change direction with only a small amount of force on the steering wheel. Power steering in vehicles can be implemented both electrically and hydraulically. In many cases, passenger cars are equipped with hydraulic steering. An electrically or mechanically driven servo pump generates the pressure required for steering assistance.

Electric power steering and steering gear

More and more cars are being equipped by the manufacturer with electric power steering. Instead of a hydraulic system with a servo pump, electric motors take over the function of steering assistance here. Depending on the design, the power acts on the steering column or the steering gear. Electric power steering systems contain fewer components that can wear out and become defective at some point. As a result, this type of power steering is considered more reliable in the long term. A mixture of both systems is represented by electrohydraulic steering systems with electric power pumps.

Steering components at a glance

Modern steering systems in cars are made up of numerous different components. For the steering to work reliably and precisely, all components must be correctly matched and function optimally. The following is an overview of the different steering components.

• Steering wheel: The steering wheel enables the driver to determine the direction of travel. The steering movement exerted here is transmitted to the steering column, which is coupled to the component.
• Steering column: The steering column provides a positive connection between the steering wheel and the steering gear. In the event of an accident, the column deforms to reduce the risk of injury.
• Steering gear: The steering gear transmits the steering movements to the steering linkage. It converts the rotational movement of the steering into a pushing movement via a toothed rack.
• Track rod: The track rod transmits the steering movement from the steering gear to the steering knuckles. To allow the front wheels to compress, the component has a ball head.
• Steering knuckle: The steering knuckles act as wheel carriers in the steering system. They can be pivoted in the steering direction and connect the wheels to the vehicle via the wheel hub.
• Power steering pump: This pump is part of the steering system with hydraulic power steering. The component provides a steady flow of hydraulic oil for steering operation.
• Servo reservoir: The servo reserv oir acts as an expansion reservoir and supply reservoir for the hydraulic oil of the power steering system. In addition, servo fluid can be topped up here if required.
• Steering angle sensor: Modern vehicles often have a steering angle sensor. The sensor records the steering angle via the position of the steering column and sends the data to a control unit.
• Universal joint: A universal joint translates the rotational movement of the steering column into a different angle. Universal joints also allow directional changes within the steering column.
• Steering damper: The steering damper dampens forces occurring in the steering system. Like steering arms, this component is nowadays mostly installed only in off-road vehicles and commercial vehicles.

Function of the steering system in the vehicle

The steering system in a car has the function of directly implementing the driver’s directional commands. This influence on the direction of travel is achieved by changing the steering angle of the wheels. In vehicles with independent suspension, the front wheels are independently spring-mounted on the vehicle. However, the special design of the steering system with movable tie rods means that the steering angle can still be changed at any time.

When the driver turns the steering wheel

If the driver wants to change the direction of the car, he turns the steering wheel. The turning motion exerted by the driver is transmitted from the driver to the steering column. This in turn is connected to the steering gear. The circular motion of the column is thus transmitted via the steering pinion to the rack in the transmission. If necessary, the power steering assists the driver’s steering movements, making the steering particularly easy to operate. In the steering gear, the interaction between the gearwheel and the rack ensures that rotary motion is converted into sliding motion. The components within the steering gear shift in the direction in which the driver wants to steer the car. The steering linkage transmits this movement to the steering knuckles or steering levers, which shift the position of the front wheels. The vehicle thus immediately changes the direction of its travel.