Hydraulic fan drive system

The technical specialists of NHC Power Components in cooperation with the Casappa company specialists have developed and introduced in series production the variants of the hydraulic fan drive of the cooling system for diesel and gas engines of the following models:YaMZ 53624, YaMZ 536, YUCHAI, MMZ, Deutz 1013, Daimler E-3,4,5, EEV, MAN 0836 LOH 64, WEICHAI WP7.NG, Mercedes M906LAG, Cummins ISB6. Cummins ISL340, Cummins L8.9.

A set of hydraulic fan drive of the engine cooling system is supplied by our company to the production lines of bus production of Russian Buses (GAZ Group), MAZ plant, Volgabus Volzhsky and other manufacturers.


During development of vehicle cooling systems NHC Power Components Close Corporation in cooperation with Casappa company implemented multiple and flexible approach in choosing an optimal solution.

The use of hydraulic fan drive system has a number of significant advantages in comparison with traditional solutions for engine cooling system. 


  • Fan speed control
  • Changing the direction of rotation
  • Energy saving - low noise level
  • Flexibility in use and long service life
  • Multiple control - reduced dimensions

Engine cooling fan drive system operation concept.

At the optimum combustion temperature in a diesel engine emission levels are significantly reduced. To maintain this temperature, the fan drive system is ideal for monitoring and maintaining the speed of the fan impeller, depending on the parameters read from the engine sensors.

The most optimal and flexible is exactly the hydraulic fan drive system of the radiator.

The complex, built on the basis of a hydraulic drive, allows to change the rotational speed of the fan impeller of the cooling system depending on the temperature read from the sensors of the engine.

Engine cooling fan drive system works as follows: a gear pump driven by an internal combustion engine supplies the working fluid to a gear motor that rotates the fan impeller which in it’s turn cools down the water cooler, oil heater and intercooler (charge-air cooler/aftercooler). The gear motor has a built-in proportional safety valve that allows the fan to rotate independently of the rotation speed of the internal combustion engine. It protects the hydraulic fan drive system from pressure spices and emergency shutdown. In the absence or interruption of the current in the circuit, the fan rotates at maximum speed, which prevents the engine from overheating. Also there is an electronic control unit, oil, water and charge-air temperature sensors, electrical harness, high pressure hoses and hoses, hydraulic tank with return filter and filling breather in the engine cooling hydraulic fan drive system. The electronic control unit reads out the temperature sensors value and, according to these readings, controls the proportional solenoid of the safety valve. Filters installed in the tank prevent the hydraulic fan drive system from pollutants of the working fluid and maintain the purity of oil at the required level.


Common view of fan drive system of engine cooling system:

1 – hydraulic pump; 2 –  motor; 3 – electronic control unit (ECU) (is not indicated on picture 1); 4 – return filter; 5 – filling breather; 6 – engine; 7 – hydraulic tank; 8 – tube; 9 – hose; 10 – high-pressure hose.