The steering system is one of the most basic in the device of the car. This is a set of mechanisms that synchronize the position of the steering wheel and the angle of rotation of the front steered wheels. The main function for any vehicle is the ability to turn and maintain the direction set by the driver.
Device
Structurally , the car steering consists of a pair of main components. As for the mechanisms, they can be implemented in different ways.
The steering wheel is necessary for control. The driver through it indicates the direction in which the car is moving. In modern cars, the steering wheel can be additionally equipped with keys and controls to control multimedia, navigation systems. If the driver replaces the multimedia system in the future, you must purchase a steering adapter to set up the radio from the steering wheel. There is also an airbag inside the element.
Next in the system is the steering column. What is it for? It is necessary to transfer the force that the driver applies to the steering wheel on the mechanism. The part is a shaft with a hinge. More often it is a small cardan. Often steering columns provide safety in the event of theft. So, the design is equipped with mechanical or electrical interlock systems. Also on the column is the ignition, levers for turning turns, turning on the lights, windshield wipers.
The steering mechanism receives force from the column shaft and then transforms it into a turn of the wheels. The design of the steering mechanism is a gearbox with a certain gear ratio.
The system also has a drive. This is a system of rods and tips that take the force from the shaft and then transfer it to the tips and the rotary system of the steered wheels.
In most steering system designs, there is an amplifier. It can be hydraulic or electric. It is necessary to increase the rotational forces that go from the steering wheel to the wheels. Additional elements can also be distinguished - these are shock absorbers or dampers, as well as various elementary systems.
Steering gears: types
Depending on which gearbox is installed in this or that car, the steering gear can be rack, worm or screw. We will consider each of them separately.
Rack and pinion
This is a widespread device, which is equipped with most modern cars. The main element is the rack and pinion. The latter is constantly engaged with the gear rack, and it is located on the steering shaft.
The principle of operation of this mechanism is as follows. When you turn the steering wheel, the gear rack moves left or right. Steering rods move with it, which are connected to the tips, and those, in turn, with steering knuckles. Thus, the wheels of the car can be rotated to the angle necessary for the driver.
The rack and pinion mechanism is quite simple, while it is characterized by high efficiency and rigidity. But with all the advantages, the steering rack is very sensitive to loads, especially to shock loads from driving on road bumps. Also, due to its construction, it is prone to vibrations. The steering rack is most often found on front-wheel drive cars, where the front suspension is an independent type.
Worm
This steering mechanism is based on a globoid worm. This is a worm shaft having a variable diameter. It is connected to the steering shaft. Also in the design there is a roller. A steering bipod is mounted on the roller shaft, which is mechanically connected to the steering rods.
During the rotation of the steering wheel, the roller runs around the worm, thereby driving the steering bipod. The latter as a result moves the drive rod. Due to this, the steering wheels are turned in the direction necessary for the driver.
This option is less susceptible to any load, including shock. In addition, large turning angles and better maneuverability for the car are provided. But there are also disadvantages. So, the worm mechanism is more complex in terms of manufacturing, and therefore more expensive. For the normal functioning of the mechanism, many connections are required, which requires periodic and complex adjustment.
This design can be found on cars with enhanced cross-country performance, as well as with dependent suspension of a pair of steered wheels. Another mechanism is found on small trucks and buses. Worm steering was installed on VAZs of classic models.
Screw mechanism
The following elements are combined in this decision. This is a screw that is mounted on the steering shaft, a nut that moves along the screw, a gear rack on the nut, a sector connected to the rack, and also a bipod. The latter is located on the shaft of the gear sector. Of the features we can distinguish the nut-screw connection. Here it is made using a large number of small balls. Balls can significantly reduce the friction between moving parts and thereby reduce the wear rate.
The principle of operation of the mechanism resembles the work of a worm system. When the driver acts on the steering wheel, the shaft is set in motion, and with it the screw that moves the nut rotates. In this case, the balls move inside the mechanism. The nut moves the gear sector when exposed to the rail. The steering wheel moves along with the sector.
This steering is more efficient than worm gear. The system is installed on executive cars, heavy trucks and various bus models.
Power steering
All of the above systems required some effort. To facilitate the operation of cars, as well as to ensure that the ride brings emotions and a good mood, the engineers created a device that allows you to drive a car with little or no effort. This device is called an amplifier. Today, most cars are equipped with such a system.
There are hydraulic, electric, hydroelectric power steering. Pneumatic mechanisms can also be distinguished.
Power steering
This is one of the structural elements of the control system. Here, when the steering wheel is rotated, the main force is generated by a hydraulic drive.
The simplest amplifier is a pump driven by a crankshaft. This solution has a performance directly proportional to the engine speed. This meets the needs of driving. If the speed is maximum, then minimum gain is required and vice versa.
This system works as follows. When driving straight, the steering pump circulates the hydraulic fluid. When the steering wheel turns, the torsion bar spins. The process is accompanied by a rotation of the spool relative to the distributor sleeve. Channels open and fluid enters one of the cavities in the ram. Fluid from another cavity goes into the tank. A piston in the power train moves the rail. The force is transmitted to the steering rods, which leads to the rotation of the steered wheels.
When cornering takes place at low speeds, the amplifier works at peak performance. Based on the signals from the sensors, the computer increases the speed of the pump. The working fluid flows more intensively into the cylinder of the power mechanism. Due to this, the force required to turn the steering wheel is reduced.
Electric power: features
A steering device of this type is more complicated. There are tons of sensors here. The system consists of an electric motor and mechanical elements. The most common designs with two gears, as well as with a parallel drive. This amplifier is often located in the same unit with the steering system mechanism.
When the driver turns the steering wheel, the torsion bar is twisted or unscrewed. This is measured by the sensor - the current torque and angle of rotation are taken into account. Also takes into account the speed of movement. All these numbers are sent to the computer, which calculates the required effort. By changing the current strength, the force on the rail of the mechanism changes.
Conclusion
These are all the steering systems of modern cars that exist today. Perhaps engineers will come up with more efficient solutions in the future. In the meantime, enough power steering.