General System Description

Fig. 1 Turbocharger system:

Fig. 2 Turbo compressor operation:

Turbocharging provides improved charging on the induction stroke, which produces more effective combustion of the mixture and an increase in power output. Effectively the engine achieves performance that is comparable to that of a larger engine, while maintaining the advantages of a smaller engine, Fig. 1.
Turbocharging is achieved by means of a turbo-compressor. This unit utilizes the exhaust gases from the engine to drive the compressor. Exhaust gas flows through a turbine wheel mounted on the same shaft as the compressor impeller. Energy from the exhaust gas velocity is thus transferred to the compressor located in the induction system. The impeller acts on the inducted air causing an increase in charging pressure in the combustion chamber, Fig. 2.
This system increases torque at engine speeds during normal driving conditions, in contrast to those designed to increase performance only at full throttle. The turbine shaft rotates at high speeds and must be very accurately balanced. The shaft rotates in floating sliding contact bearings. These bearings utilize high pressure oil as the contact surface for the shaft. A special line supplies lubricating oil from the pump. Oil is returned to the sump through a large bore pipe. Sealing between the shaft and the bearing housing consists of sealing rings installed in grooves.