A modern car cannot be imagined without an effective control system, and the key element here is the power steering. A few decades ago, drivers of sports cars and heavy trucks could boast of developed muscles of the hands, because to twist the "ram" without the help of technology was a real test. Today, even a child can easily turn the wheels of a parked car with one finger, which has become possible thanks to the introduction of various reinforcement systems.
The evolution of these mechanisms has come a long way from simple hydraulic circuits to complex electronic complexes with artificial intelligence. Understanding how it works power-pilotIt is necessary not only for engineers, but also for every car owner who wants to avoid expensive repairs. Depending on the design, these systems can dramatically affect driving patterns, fuel consumption and the feeling of feedback on the road.
In this article, we will discuss in detail the main types of amplifiers, their design features and hidden nuances of operation. You will learn why some drivers prefer a heavy steering wheel, while others appreciate the weightlessness of control in the parking lot. We will also touch on maintenance issues that will help prolong the life of the node and avoid sudden breakdowns on the way.
Hydraulic power steering: classics of the genre
Hydraulic power steering, or GURGFor a long time it remained an uncontested standard for the mass automotive industry. The principle of its operation is based on the circulation of liquid under high pressure, which is created by a pump driven by an internal combustion engine through a belt transmission. When you turn the steering wheel, a special distributor directs the flow of oil into one of the cylinder cavities, pushing the piston and making it easier to turn the wheels.
The main advantage of such a system is its ability to transmit to the steering wheel a natural sense of the road, the so-called "feedback". The driver feels the wheel resistance and road surface, which allows you to assess the situation more accurately. However, hydraulic pump It works constantly while the engine turns, which creates a parasitic load on the engine and increases fuel consumption, albeit slightly.
⚠️ Attention: In systems with GUR, it is categorically impossible to keep the steering wheel in an extreme position for a long time. The pressure in the system reaches peak values, which can lead to rupture of hoses or failure of the pump ossels.
Maintenance of hydraulics requires regular monitoring of the level and condition of the fluid. Over time, the oil loses its properties, is saturated with wear products and water, which leads to corrosion and bullying in the nodes. If you hear a hum when you turn the steering wheel, this is the first signal that GOOR pump Or the fluid itself needs attention.
- 🛑 Constant load on the engine even on a straight road.
- 💧 Risk of leakage of hydraulic fluid due to ageing of rubber bands.
- 🔧 Relative simplicity of design and repairability.
- 🛣️ Great sense of the road at high speeds.
Power steering: the digital era
With the advent of modern environmental standards and the development of electronics, hydraulics came to replace the power steering (ERM). This system lacks fluid, pump and belts. Instead, the force is created by an electric motor that can be mounted on the steering shaft, in the steering column, or integrated directly into the steering rack. Motor control is taken over by an electronic unit that analyzes the speed of rotation of the steering wheel and the speed of the car.
The main advantage of ESD is energy efficiency. The electric motor consumes current only at the time of turning the wheels, and on a straight road the system is completely switched off, saving fuel. In addition, the lack of hydraulics eliminates the risk of leaks and makes it easier to implement functions such as: parking assistant Lane Keeping Assist, when the car drives in the lane.
Diagnostics of EUR often require the connection of an OBD-II scanner to read the error codes of the torque sensor.However, electric power generators have their critics. Many drivers complain about the “vatality” of the steering wheel and the lack of honest feedback, especially on older or budget models. Electronics can artificially weight the steering wheel on the track and make it easier in the city, but these algorithms don't always perfectly mimic the physics of a road spot. However, the reliability of modern electric motors The gearboxes are high enough, provided the on-board network is in good condition.
Why is EUR often put on small cars?
Manufacturers love EUR for the simplicity of the layout in the hood space and the ability to fine-tune the effort in a software way, without replacing the "iron".
Electrohydraulic amplifier: hybrid solution
electrohydraulic amplifier, or egourIt is an attempt to combine the reliability of hydraulics with the economics of electrics. Externally, the system is similar to a conventional GUR: there is also a liquid, rake and hydraulic cylinder. The key difference is the source of pressure: instead of a mechanical pump, an electric pump is installed on the belt, which is turned on only by command of the control unit.
This design allows you to maintain a pleasant feeling of the road, characteristic of hydraulics, but get rid of the constant power take-off from the engine. EGUR can often be found on premium cars of previous years or on heavy SUVs, where pure electrics can not cope with heavy loads without a significant increase in size.
Despite the apparent advantages, electrohydraulic It has its weaknesses. The system remains complex, combining the disadvantages of both worlds: liquid can flow, the pump wears out and electronics can fail. In addition, electric pumps often operate at very high pressure, which places increased demands on the quality of seals.
- ⚡ Fuel savings compared to the classic GUR.
- 💦 Preservation of the hydraulic feel-effect of control.
- 🏗️ Complexity of design and high cost of components.
- 🔋 Dependence on the voltage of the onboard network.
Comparative table of system characteristics
To better navigate the differences, it is worth considering the summary data on the main parameters. Each system has its own niche application, and the choice depends on the priorities of the manufacturer and the class of the car.
| Parameter | GUR (Hydraulica) | EUR (Electro) | EGUR (Electrical hydraulics) |
|---|---|---|---|
| Power source | Engine (belt) | The power grid | The power grid |
| Fuel consumption | Above (constant load) | Below (only in the corner) | Medium/Low |
| Feedback | Great, natural. | Artificial, software dependent | Good, close to hydraulics. |
| Service | Replacement of fluid, belts | Minimum | Replacement of fluid, electrical control |
| Risk of breakdown | Leaks, pump wear and tear | Sensor failure, motor failure. | Combined |
When buying a used car, be sure to check for under-hood stains in the area of the steering rack - this is a sure sign of problems with GUR or EGUR.
Diagnosis and typical malfunctions
Regardless of the type of system installed, it is subject to wear. In hydraulic amplifiers, the most common problem is the wear of the ossels and the appearance of backlashes in the pump. Drivers notice this by the appearance of knocks when the steering wheel is rotating or a characteristic howl. If the level of liquid in the tank falls, and oil stains appear under the car, slow down with repairs. steering-rail You can't.
In electrical systems, things are different. Here most often fail to torque sensors or the electric motor itself. Symptoms are the lighting of the malfunction lamp on the dashboard, spontaneous steering or complete lack of effort. Sometimes the problem lies not in the node itself, but in poor mass contact or generator voltage surges.
⚠️ Warning: If a red steering malfunction light is lit on the panel, the movement is dangerous to continue. The steering wheel can become completely jammed or unliftable at a critical moment.
Diagnosis should begin with a visual examination and checking the level of fluids. For EUR, computer diagnostics is required, which will show error codes. Do not ignore the squeaks or clicks - these are the first bells preceding a serious breakdown. bearing Or gear gears.
☑️ Check-up steering.
Choosing oil and hydraulics maintenance
For owners of cars with GUR and EGUR, the question of choosing working fluid is especially acute. Oil performs not only the function of pressure transfer, but also lubricates rubbing vapors, and also removes heat. Using the wrong liquid or mixing different types (e.g. mineral and synthetic) can cause rubber seals to swell and the system to fail quickly.
Manufacturers often specify the specification of the liquid in the instructions, for example, ATF Dexron ordnance Pentosin. Before adding always check with the tolerances indicated on the cover of the tank.
Replacement of liquid is recommended every 60-80 thousand kilometers or once every 3-4 years, even if the manufacturer claims "pouring for the entire life." Old oil loses its viscosity and anti-corrosion properties, turning into an abrasive mixture that kills an expensive pump.
Timely replacement of liquid in the GUR is the cheapest way to avoid replacing the entire steering rack assembly, the cost of which can reach half the cost of a used car.
Why is the GUR pump buzzing?
The pump buzz usually indicates cavitation – air entering the system or low fluid levels. Also, the sound can occur due to wear of the bearings of the pump shaft or contamination of the mesh in the tank.
Can I drive with a faulty ESD?
Technically, the car will remain manageable, but it will take much more effort. However, it is not recommended to operate a machine with a burning lamp of an EUR error, since the system can behave unpredictably at high speed.
How often should I change the fluid in the hydraulic booster?
The optimal replacement interval is every 60,000 km of run or every 3 years. If the liquid has darkened and smells burnt, the replacement should be made immediately.