One of the main systems of a car is steering, which is a set of mechanisms that synchronize the angle of rotation of the wheels of the main axis and the position of the steering wheel. Steering requires regular diagnostics and technical inspection, the conduct of which depends on the design features and the type of assembly.
Steering purpose
The driver is required to control the position of the vehicle relative to other road users and the allocated lane while driving. To change the route or perform maneuvers, the driving mode is changed using the braking system and steering.
Elimination of lateral sliding and stabilization of the steered wheels is carried out by means of a steering drive, which returns the car to a straight course of movement after the driver stops making efforts to the steering wheel.
Steering gear
The steering system device includes the following elements:
- Steering wheel. Used to control the car and adjust the direction of its movement. Modern models are equipped with multifunctional steering wheels equipped with an airbag.
- Steering column. It transfers forces from the steering wheel to the steering mechanism and is represented by a shaft with articulated joints. Electric or mechanical locking and folding systems guarantee car theft protection and safety. The steering column is equipped with an ignition switch, a windshield wiper and lighting control elements.
- The steering mechanism transfers to the wheel drive the forces created by the driver through the rotation of the steering wheel. It is represented by a gearbox with a certain gear ratio. A driveshaft connects the steering gear to the steering column.
- The steering drive is structurally represented by levers, tips and steering rods, which transmit rotary fists effort from the steering mechanism.
- Power steering - facilitates driving and increases the force transmitted to the drive from the steering wheel.
- Additional structural elements - electronic systems, shock absorbers.
The steering and suspension of the car are closely related: the degree of response of the vehicle to the rotation of the steering wheel depends on the height and stiffness of the suspension.
Types of steering system
The steering mechanism can be divided into several categories depending on the type of gearbox:
- Rack and pinion. It is considered the most common and is installed on cars. The mechanism with the simplest design and characterized by maximum efficiency. The minus is the sensitivity to shock loads that occur during operation of the car in difficult road conditions.
- Worm. Provides a large angle of rotation of the wheels and good maneuverability of the car. The mechanism is practically not subject to shock loads, but its production is more expensive.
- Screw. By the principle of operation, it is similar to the worm type, however, it is distinguished by high efficiency and creates great efforts.
Amplifier Classification
Steering systems are divided into several types, depending on the type of installed amplifier:
- Hydraulic (Power Steering). The advantage is simplicity of design and compact size. Hydraulic steering systems are one of the most common and are installed on most modern cars. The disadvantage of this control is the need for regulation of the level of the working fluid.
- Electric (EUR). Progressive management system. The amplifier ensures the reliability of the system, fuel economy, the ability to drive a car without a driver and facilitates control settings.
- Electrohydraulic (EGUR). According to the principle of operation, the system is similar to a hydraulic amplifier. The main difference is the functioning of the pump, which is not driven by the internal combustion engine of a car, but by an electric motor.
Additional systems
The steering of modern cars are equipped with various systems:
- Active Steering (AFS). Adjusts the gear ratio depending on the speed of movement. It guarantees safe and stable movement on a slippery track due to the correction of the angle of rotation of the wheels.
- Dynamic steering It functions similarly to the active system, however, the electric motor takes the place of the planetary gear in the structure.
- Adaptive steering. A feature is the lack of a rigid connection between the wheels and the steering wheel of a car.
Steering Requirements
According to the standards, the following requirements are imposed on the steering system:
- Providing the necessary trajectory according to the parameters of maneuverability, stability and agility.
- The force exerted on the steering wheel must not exceed the specified values.
- The number of revolutions of the steering wheel from the standard position to any of the extreme must comply with the standards.
- The ability to drive a car must remain after the amplifier fails.
The normal functioning of the steering system is determined by another parameter - the total play, implying the angle of rotation of the steering wheel until the wheels turn.
The permissible total play in the steering must comply with the accepted standards:
- For minibuses and cars - 10 degrees.
- For buses and similar vehicles - 20 degrees.
- For trucks - 25 degrees.
Features of right-hand and left-hand drive
Depending on the legislation of specific countries and the type of vehicle, modern cars are divided into right-hand drive and left-hand drive. Accordingly, the steering wheel can be located both on the right and on the left. For example, VAZ steering systems are left-hand drive.
The mechanisms differ not only in the position of the steering wheel, but also in the gearbox, which is adapted to the specific side of the connection. Despite this, right-side management on the left-side can be redone.
Some types of special equipment are equipped with hydrostatic steering, which ensures the independence of the steering wheel from other elements. Such a steering system does not have a mechanical connection between the steering wheel and the drive, and the wheels are rotated using a power cylinder controlled by a metering pump.
Compared to standard mechanisms, hydrostatic steering does not require much effort to make a turn, does not have a backlash, and its layout implies an arbitrary arrangement of structural elements.
Accordingly, hydrostatic control provides both left-side and right-sided control. Thanks to this, the system can be installed on special vehicles.
Causes of System Failures
The steering mechanism, like any other elements, is prone to breakage. The causes of malfunctions can be several:
- Aggressive driving style, harsh vehicle operating conditions.
- Poor track coverage.
- Use of non-original components.
- Untimely maintenance.
- Repair work by incompetent craftsmen.
- Exceeding the operational life of the equipment.
Problems with the braking or steering systems of the car can lead to an emergency on the road.
Types of malfunctions and their symptoms
The vehicle steering system may fail over time. The appearance of breakdowns is accompanied by certain signs:
- When third-party knocking occurs, the steering gear hinge changes.
- Steering wheel vibration is eliminated by proper wheel alignment.
- When the wheels beat, their settings are changed, the components of the steering rods or the column bearings are replaced.
- Draft tips change with a backlash of more than 10 degrees.
Diagnostics and maintenance
To eliminate problems with the steering system of the car, it is important not only to regularly carry out maintenance, but also to diagnose the main components and assemblies.
Be sure to check the backlash using a special device - a backlash meter. It is advisable to check the system for jamming.
During the technical inspection, the condition of the hydraulic booster is assessed. If the oil level in the system is lower than required, then it is topped up. The steering housing is diagnosed, the level of tightening of the wedges, trunnions, cotter pin, the latter - after lubrication of the steering link.
Subsequent technical inspections involve a set of diagnostic procedures implemented using special equipment. Repair of the steering system is best done in service centers where professionals work.
Masters should check the total backlash of the mechanism using a backlash meter. For cars, it should be equal to 10 degrees.
The importance of steering performance
A vehicle is considered a source of increased danger, and therefore, to prevent accidents, the car owner is required to maintain the vehicle in good condition and regularly monitor the technical condition.
The main purpose of the steering system is to provide control of the machine. An intact mechanism guarantees safe and confident movement, which is important not only for the driver, but also for passengers.
The traffic rules indicate that it is forbidden to continue driving and operate a car with a failed steering system, in the presence of play, oil leaks from the rack.
A good control system has a significant impact on the condition of the car’s rubber: tire wear should be uniform in order to avoid loss of control, ejection while driving off the track and the occurrence of malfunctions of other vehicle components and assemblies.
Steering is one of the most important structural elements of a modern vehicle and requires regular monitoring of its condition and competent technical inspection and repair work. Driving a car with a failed steering system is prohibited in order to avoid emergency situations on the highway and to maintain the safety of the driver, passengers and other road users.