The turbocharger is mainly composed of several parts, which are the shell (including the turbine shell and the pressurized impeller shell) and the rotor (including the turbine and the impeller). The exhaust gas drives the turbine to generate power, which drives the impeller to compress air), intermediates (internal lubricating oil channels and bearings, which dissipate heat and reduce friction), sealing rings (which seal), pressure relief valves (at the moment of oil intake, since the engine is no longer needed to generate as much power), So there is no need for a large amount of air into the cylinder and at this time the supercharger because of inertia rotation still produce pressure, at this time it is necessary to release the pressure relief valve, prevent parts from damage because of too much pressure).
When really working, because the impeller compressed air will raise the air temperature, too high intake temperature will reduce the efficiency of the engine, so the intercooler that cools the air is also needed to assist the work.