Turbocharger Knowledge Center

1.Take you to the details of turbochargers

Turbocharger structure and descriptione2

Three dimensional diagram of turbocharger

Turbocharger 3D disassembly diagram

The turbocharger is installed on the exhaust pipe of the engine, directly in contact with the exhaust gas of the internal combustion engine up to 600~850°C, and the rotation under the calibration condition is as high as 60,000 ~ 160,000 RPM, so it must be used and maintained in strict accordance with the manual of the engine manufacturer or the recommendations of the turbocharger manufacturer. The turbocharger with air release valve takes into account high and low speed performance, low speed torque, strong climbing ability and rapid acceleration. The vent valve is connected to the air outlet of the turbocharger which opened and closed by the boost pressure. After the exhaust valve is opened, part of the engine exhaust gas does not enter the exhaust pipe directly through the turbine, so as to control the increased pressure, limit the explosion pressure in the cylinder, and prevent the mechanical load of the engine from exceeding the allowable value.

B.How a turbocharger works

Turbocharger is the use of high temperature and high pressure exhaust gas discharged by the engine, the exhaust gas expands and does work in the turbine, drives the turbine to rotate and at the same time drives the coaxial compressor impeller to rotate at high speed, a large number of fresh air through the rotation of the compressor impeller is inhaled and compressed, into the engine cylinder, due to the increase in the charging volume, the air density increases, so as to make more fuel fully combusted and greatly increases the power of the engine under the condition of constant size.

C.The advantages of the turbocharger

1. Improve the power of the engine; 

2. Improve engine fuel economy; 

3. Improve engine emissions; 

4. Play the role of plateau power recovery.

D.Main components of turbocharger

1. Shell system; 

2. sealing system; 

3. wheel, shaft system; 

4. heat insulation system; 

5. Thrust system;

6. Fastening system; 

7. Bearing system; 

8. Bypass valve system.

(1)Shell system

(2)Wheel and shafting system

                   

(3)Thrust system                                                       (4)Shaft bearing system

(5)Sealing system

(6)Heat insulation system                           (7)Fastening system                                             (8)Bypass valve system

2.Turbocharger use and maintenance knowledge

1). Before installing the turbocharger, check whether there is debris in the inlet and exhaust pipes; Whether the air filter is clean and intact; Whether the inlet and return pipelines are clean and smooth; Whether the oil filter is clean and intact; Whether the oil deteriorates and becomes dirty; Whether the gaskets of the inlet and exhaust connection ports are damaged.

 2). When installing a new turbocharger or starting a long-discontinued turbocharged engine, an appropriate amount of clean CD lubricating oil should be injected into the turbocharger oil inlet hole, and the rotor assembly should be turned by hand to fully lubricated the bearing

3), after starting the engine, it is not allowed to run at full load immediately, the turbocharged engine should first idle for 3 to 5 minutes before stopping, so that the turbocharger is pre-lubricated to prevent the turbocharger oil shortage to resulting in bearing death.

4), turbocharged engine oil must use CD supercharged oil, it is recommended to use lubricating oil: 20W/50CD or 15W/40CD in summer, 10W/40CD or 5W/40CD in winter

5), regular maintenance of the air filter, so as not to make the compressor impeller of the turbocharger negative pressure too large,which will lead to turbocharger over-temperature working and resulting in oil leakage.

6), regular maintenance of the oil filter, so that the oil is not too dirty (impurity particles in the oil < 0.015mm, the filter element in the breakdown state), resulting in serious wear of the turbocharger bearing sleeve and thrust bearing.

7). In the inlet of the compressor housing and the exhaust gas inlet of the turbine box, no foreign matter is allowed to exist, otherwise the impeller and turbine will be broken.

8), turbocharger with bypass valve, its opening pressure has been adjusted by the manufacturer, can not be adjusted at will, so as not to cause engine performance decline, serious damage to the turbocharger.

9). It is strictly prohibited to use the operation method of "acceleration → flameout → neutral sliding"

3.Turbocharger maintenance:

1). Regular maintenance: check whether the pipe connection between the air filter and the compressor inlet is firm and sealed, and whether there is air leakage and oil leakage,prevent foreign matter from entering the compressor impeller; Check whether the connection bolts and clamp bolts between the turbocharger and the engine inlet and exhaust pipe are firm and whether there is air leakage; Check whether the connecting bolt at the inlet and return oil pipe joint of the turbocharger is firm. The inlet and return oil pipe must be clean and unblocked, and no dirt is allowed to block the pipe. Check the quality of lubricating oil and pay attention to whether the oil is too dirty or deteriorated.

2).Timely maintenance: regular replacement of lubricating oil, the engine every 150 ~ 200 hours or after driving 5000 kilometers, the lubricating oil should be replaced; The engine should be cleaned once every 100 to 150 hours. (If the filter element is damaged, it must be replaced immediately); Hold the locking nut at the end of the compressor impeller with your fingers, push and pull axially, and feel the axial clearance should be within 0.08 ~ 0.25mm; Radial swing up and down, feel radial gap should be in the range of 0.3 ~ 0.6mm.

4.Turbocharger common failure mode:

1.Oil leakage at the compressor end of the turbocharger; 

2. Oil leakage at turbocharger vortex end; 

3. Turbine and impeller of turbocharger rub shell; 

4. The turbine and impeller of the turbocharger are damaged by foreign bodies; 

5. Turbine and impeller of turbocharger are damaged due to casting reasons; 6, the turbocharger rotor shaft is broken.

1.Oil leakage at the compressor end of turbocharger:

Inspection method: 

If the turbocharger compressor end oil leakage under the circumstance that the axial and radial clearance in good condition,there will be oil traces in the air outlet of the compressor, which is manifested as oil leakage traces in the connecting hose of the compressor air outlet on the engine. There is a large amount of dust attached to the surface of the impeller and the air inlet.

liability determination: 

If the axial and radial clearance of the turbocharger is good, the steel wheel of the impeller is not damaged, and the rotation is flexible, the oil leakage occurs. In the case of excluding other influencing factors of the engine, it is preliminatively concluded that the sealing ring failure causes the oil leakage, and the factory is responsible for the problem. If the oil leakage is caused by engine related factors such as poor intake, it is the user's responsibility, please exclude the engine influence factors in time.

2.turbocharger vortex end oil leakage:

Inspection method: When the axial and radial clearance of the turbocharger is good ,the turbine and impeller are not damaged, there is oil leakage at the turbocharger turbine end, usually there will be oil stains on the turbine surface, the engine will emit blue smoke, and there is oil in the exhaust gas.

Liability determination:

1) If the axial and radial clearance of the turbocharger is good, and the rotation is flexible,the turbine end oil leakage occurs.

In the case of excluding other factors affecting the engine, the initial conclusion is that the sealing ring failure caused the oil leakage, and the factory is responsible;

2).if the engine idle time is too long caused turbocharger vortex oil leakage, the user is responsible. 

The turbocharger itself has no quality problems, please clean the oil stain at the turbine end in time, and operate according to the idle time specified by the turbocharger.

3.Turbocharger turbine and impeller rub shell

Inspection method: Remove the faulty turbocharger from the engine, hold both ends of the rotor with your fingers and shake it. 

If the axial clearance of the rotor is ≥0.12mm, or the radial clearance of the rotor is ≥0.40mm, the impeller is not flexible when rotate by hand, and there is stuck or shell friction; There are significant friction marks on the turbine and impeller.

Liability determination:

1.if the oil or oil circuit dirty, oil coking caused turbocharger core parts of abnormal wear, rotor shaft axial and radial clearance deviation from the process value, resulting in turbine and impeller rub shell lead to turbocharger broken. This is user's responsibility.

2.if the inlet pipe and compressor cavity dust or short circuit lead to turbocharger core parts abnormal wear, turbine and impeller rub shell caused damage to the turbocharger is the user's responsibility.

Dirty oil or oil circuit, poor oil quality cause a lot of impurities and coke in the thrust bearing oil hole, oil groove accumulation, thrust bearing wear seriously.

3. If the rotor shaft is burned or worn due to non-operation according to the regulations (immediately blast the throttle after starting, repeat hot stop or do not idle for 3~5 minutes after starting and before stopping; Or "acceleration → flameout → off-gear coasting".). user is responsible for the damage of turbocharger.

4, if due to insufficient oil or low oil pressure lead to the turbocharger core oil shortage, rotor shaft ablation, floating bearings and thrust bearings lack of oil dry grinding, parts damage.These may make fit clearance of turbocharger is larger than the process value. The user is responsible for the damage of the turbocharger.

5, oil cleaning or machine filter element no blockage, no lack of oil but the turbocharger shell and other faults, it is the quality of the turbocharger parts.

The rotor shaft is seriously ablated, and the contact part with the floating bearing is seriously dry wear marks.                

Seal sleeve ablated, rot.

4.The turbine and impeller of the turbocharger were damaged by foreign bodies

Inspection method: Remove the faulty turbocharger from the engine, check the damage of the turbine and impeller, whether there is a foreign body impact trace, whether there is a foreign body in the inlet and exhaust of the turbocharger.

1.The end of the compressor impeller is damaged by foreign matter, which is caused by foreign matter entering the compressor housing from the intake pipe or air filter

2.The turbine radial is damaged by foreign matter, which is caused by foreign matter entering the turbine housing from the diesel exhaust pipe. Liability determination: If the turbine and impeller wheel damage not quality problem of the turbocharger itself. it is the user's responsibility.

The end of impeller is broken by foreign matter

5.The turbine and impeller of turbocharger are damaged due to casting reasons

Inspection method: 

Remove the faulty turbocharger from the engine, check the damage of the turbine and impeller, and determine whether it is the quality of the wheel blades themselves.

1.A single blade of the compressor impeller falls off, or split from the middle or the back part of the impeller, and there are obvious casting cold insulation defects.

2.A single blade of the steel wheel turbine falls off or there is a blade fracture.

Responsibility determination: 

The turbine and impeller blade damage caused by the casting quality problem of the turbocharger itself is the responsibility of the factory.

Turbine wheel and impeller wheel damaged due to casting problems

6.The rotor shaft of turbocharger broken

Inspection method: 

Remove the broken shaft turbocharger and observe around the fracture of the rotor shaft: 

the rotor shaft is blue, the surface of floating bearing with black oil, the surface of the thrust bearing is dry, the oil quality is dirty,many impurities, and the rotor shaft is broken.

Turbocharger internal lack of oil, resulting in hardening of the rotor shaft, long-term use in poor working conditions, the rotor shaft burst.

Responsibility: 

If the shaft is broken due to the core oil shortage or other problems caused by the rotor shaft ablation, it is the user's responsibility.

5.common faults and solution

Common fault phenomena										Fault cause	solution
Engine power is not enough	Engine oil consumption is too large	Generator exhausts and gives off black smoke	Generator emits blue smoke	Fuel oil consumption of the generator is too high	The operating noise of the booster increases	The booster has a periodic sound	The booster has an unusual sound	Compressor side sealing ring leakage	Turbine side sealing ring leakage
▲	▲	▲	▲	▲				▲		The air filter is blocked and stained	Clean or replace the engine manufacturer recommended air filter
▲	▲	▲	▲	▲	▲	▲	▲	▲		Compressor inlet pipe is blocked or damaged	Remove obstructions or replace damaged parts
▲		▲			▲		▲			Compressor to engine intake pipe blocked, damaged	Remove obstructions or replace damaged parts
▲		▲			▲		▲			Engine intake pipe is blocked and damaged	Refer to the engine manufacturer's manual to remove obstructions or replace damaged parts
					▲		▲			Air leakage and damage of air filter to compressor inlet pipe	Replace fasteners, seals, gaskets, or tighten fasteners
▲	▲	▲	▲	▲	▲					Air leakage and damage of compressor to engine inlet manifold	Replace fasteners, seals, gaskets, or tighten fasteners
▲	▲	▲	▲	▲	▲					Air leakage between engine intake manifold and cylinder head intake port	Replace fasteners, seals, gaskets, or tighten fasteners by referring to the engine manufacturer's manual
▲	▲	▲	▲		▲			▲		Exhaust Exhaust pipe The exhaust pipe and main pipe are blocked	Refer to the engine manufacturer's manual to remove obstructions
▲		▲			▲		▲	▲		Refer to the engine manufacturer's manual to remove blockages	Replace the gasket, tighten or replace the fastener

					▲		▲			Exhaust pipe leak behind turbo outlet	Refer to engine manufacturer's manual to remove obstruction or replace exhaust pipe.
	▲		▲					▲	▲	Turbocharger oil return pipe clogged, poor oil return	Clear obstruction or replace damaged return oil pipe.
	▲		▲					▲	▲	Turbocharger intermediate lubricant coking and/or sludge accumulation	Refer to the engine manufacturer's manual, change the engine oil and oil filter recommended by the engine manufacturer, repair or replace the turbocharger
	▲		▲		▲		▲	▲	▲	Oil level in engine sump too high/low
▲		▲		▲						High-pressure fuel injection pump or injector failure or abnormal condition	Refer to the engine manufacturer's manual to replace or adjust the high-pressure fuel injection pump or injectors, and repair the engine if necessary.
▲		▲		▲						Incorrect engine timing mechanism	Refer to the engine manufacturer's manual to find the cause and repair the engine if necessary.
▲	▲	▲	▲	▲				▲	▲	Worn engine piston rings or cylinder liner, outgassing	Refer to the engine manufacturer's manual to find the cause and repair the engine if necessary.
▲	▲	▲	▲	▲				▲	▲	Engine intake valve or piston coking	Refer to the engine manufacturer's manual to find the cause and repair the engine if necessary.
▲	▲	▲	▲	▲	▲	▲	▲	▲	▲	Diffuser blade or compressor impeller fouling	Send the turbocharger to a  service station to find the cause; clean, repair or replace the supercharger.
▲	▲	▲	▲	▲	▲	▲	▲	▲	▲	Turbocharger broken	Send the turbocharger to service station to find the cause of the damage and correct it, repair or replace the turbocharger
	▲		▲					▲	▲	Engine crankcase gas pressure too high	Refer to the engine manufacturer's manual to clear the blockage