Posted By nextmg

Radiator Fan: working principle

Today I want to talk about the principle of operation of the radiator fan. Its blades are arranged so that the air supply was more massive cooling and thus more effective. For this purpose the blades of the fan which is not less than four, are in general pulley at a certain angle to the field rotation.

The type of the drive depends on the type of radiator fan. Exist: mechanical; electrical; hydromechanical.

The mechanical drive of the fan heatsink

Radiator fan-driven – from the crankshaft via a belt drive, made a permanent drive. In this embodiment, there is a serious flaw, such as a high expenditure on motor to force the fan to rotate. Therefore, from such a drive fan manufacturers cars abandoned almost completely.

The electric radiator fan drive

Fan drive with a radiator has its principle of operation, perhaps the most common in modern auto industry. This cooling mechanism includes an electric motor and control system. Sam elektrodvizhok powered from vehicle on-board network. Intelligent control system itself calculates the radiator fan operation, focused on the degree of temperature rise. In many modern cars already there is a function of the fan overrun managed. This is done so that when the vehicle is stopped and turned off the engine, the engine would have blasted the fan. “Ostuzhennoy” mode the control system will select their own, relying on the degree of heating of an automobile engine.

The scheme of inclusion of the fan of the motor vehicle engine cooling system 2107:

Driving the motor until the engine cooling fan radiator fan Hydromechanical drive

Such drive the car fan can be represented by a hydraulic coupling or a viscous clutch. Regarding the latter, then there is a constant drive shaft carried knee. Coupling may be blocked silicone fluid that is inside it. From the engine heat engine speed increases, the clutch can be blocked in whole or in part, and it will launch the fan mechanism. The hydraulic clutch is in the oil, which amount depends on the degree of heat. When will the desired change in the coupling of content, it is again blocked, and the cooling mechanism starts automatically.

As for the typical fan-by-wire control circuit, it comprises the following elements:

Coolant temperature sensor, which detects the coolant temperature. I must say that such sensors on a car can be a little. One is mounted on the radiator outlet, and another inlet. Based on the difference between the performance of these sensors will be fan control.

The relay of the fan is turned on.

The electronic engine control unit.


In addition to drive the fan, automakers use other input devices. In this list there are: air flow meter and the engine speed sensor. Indicators of these sensors is also very important, as the basis of these, more accurately determined by engine operation.

These signals enter the electronic engine control unit. Once the information is processed, can be activated radiator fan relay ON.

In those vehicles, which are equipped with a trailer hitch, or air conditioner is usually installed just 2 fan that can operate either separately or simultaneously. Each car fan there is his inclusion of the relay.

In the modern world are increasingly began to use instead of the inclusion of the fan relay is the fan control unit. Through it provides an economical and efficient operation of the cooling device.