The turbocharger design is an assembly of stator boxes in which the turbine wheel and the compressor wheel are installed on special bearings on the common shaft. The turbine wheel is driven by exhaust gases from the engine while the compressor wheel creates an air overpressure to the engine charging line. One of the basic methods of regulation of the turbocharger is to relieve exhaust gases upstream of the turbine. The increasing trend of turbocharged engines is caused by the efforts of the manufacturers trying to achieve, among other things, also a maximum flexibility and acceleration capacity of the engine. The main tool for the achievement of these parameters is the regulated turbocharger.
It depends on the level of precision and carefulness during production of all parts, including the one-hundred-per-cent balancing of the compressor wheel and the shaft with the turbine wheel. For the reasons of high speed values (as much as 200,000 rpm), the largest wear arises on radial bearings and subsequently it is possible to register damage to the O-rings of the sealing system.
Assurance of optimum turbocharger operation conditions
If optimum operation conditions are ensured, mainly cleanness of lubrication oil, the manufacturer states the lifetime of the turbocharger bearings as high as 6,000 engine operation hours. The reality is, however, that oil is penetrating into the charging line through the turbocharger already after driving 150,000 kilometres. Upon this finding it is unconditionally necessary to carry out an overhaul of the turbocharger through the exchanging of the repair set, i.e. new bearings and seal O-rings. For this method of repair, TurboCar offers the best prices to all customers.
Legend: 1) Engine; 2) Air cooler; 3) Pressure air; 4) Oil inlet; 5) Turbine wheel; 6) Exhaust gas outlet; 7) Regulation valve flap; 8) Compressor box; 9) Air entry; 10) Suction wheel; 11) Oil outlet; 12) Exhaust gas stream
If the right operation conditions are maintained, i.e. clean through-pass oil in the turbocharger, and if the exhaust gases are not too hot, turbochargers are very reliable. The correct handling is therefore very important. After a fast drive (or a drive at a high power output) it is necessary to let the engine run before turning off still for about 2 minutes in an idling mode and thus to make it possible for the turbocharger to cool down. If this is not carried out and the engine is turned off, the oil will stop circulating and will remain in an overheated turbocharger where its over-burning may occur. The over-burnt oil then may clog its inlet and this situation may lead to a damage to the turbocharger. Turbo-diesel engines are not so vulnerable to this process because the temperature of their exhaust gases is lower than in the case of petrol engines.