Special Turbo Training

Turbocharger Training

New Plant Charleston

(Opened July 2006) 200K units capacity

by 2008

USA - Columbus21 People

USA - Memphis6 People

USA - Charleston298 people510k Capacity 2005610k by 2008

Brazil - Sao Paulo25 People60k capacity 200670k by 2008

Holland - Amersfoort10 People

India - Pune45 People

China Wuxi386 People 390K capacity 2005 506K by 2006

India - Dewas180 People300k Capacity 2005390k by 2006

UK - Huddersfield895 People425k Capacity 2005-onwards

A Global Presence with Increasing Capacity

Huddersfield

- Headquarters- Customer Account Teams- Technical Centre- Manufacturing- Aftermarket

UK

Columbus

Customer Account Teams Charleston

Manufacturing Memphis

Aftermarket

USA

Dewas

Customer Account Teams Manufacturing Aftermarket Service Support

Pune

Customer Account Teams Service Support

India

Wuxi

Customer Account Teams Technical Centre Manufacturing Aftermarket

Shanghai

Customer Account Teams

China

Guarulhos (Sao Paulo)

Customer Account Teams Manufacturing Aftermarket

Brazil

Agenda

Why turbocharger

What is turbocharger

How it works

Balancing

Failure diagnosis

Why Turbocharger

Power developed by an engine is related to air consumption.

More Air MASS (+ fuel) = More Power

++ OO22 == POWERPOWER

Why Turbocharger

Engine Power

OO22

Excess Fuel Added to EngineExcess Fuel Added to Engine

Why Turbocharger

Adding Extra Fuel

Increase the size of engineIncrease the size of engineor turbocharge?or turbocharge?

4cyl 4litre4cyl 4litre80HP80HP

247 kg247 kg

6cyl 6litre6cyl 6litre120 HP120 HP344 kg344 kg

4cyl 4litre Turbo4cyl 4litre Turbo122 HP122 HP286 kg286 kg

Why Turbocharger

Increasing Engine Size

EngineEngine

SuperchargerSupercharger

AirFilter

275hp

Theoretical increase200hp to 275hp

Uses 50hp X

Actual225hp

Why Turbocharger

Supercharging

Less OLess O2 2 at high altitude isat high altitude isinsufficient to burn all the fuel.insufficient to burn all the fuel.Low power and black smokeLow power and black smoke.

Turbocharger rotates fasterTurbocharger rotates fasterto increase delivery of Oto increase delivery of O2 2 to engine.to engine.Clean emissions and powerClean emissions and power

Why Turbocharger

Altitude Compensation

Major Components of a Turbocharger

Bearing Housing

Compressor Wheel

Turbine Housing

Turbine Wheel

Compressor Cover

Applications

Small, for 3 to 6 litre engines Used on light duty truck, compressors, small

plant and light duty generators.Mid Range, for 6 to 9 litre engines

Used on local delivery truck, buses, off highway vehicles and plant and agricultural equipment.

Some products in the Indian market

How a turbocharger works ?

How turbocharger works

How a Turbocharger Works

The Turbine End

The Compressor End

The Oil Supply


The turbine housing is boltedto the exhaust manifold of theengine.

The waste exhaust gasses are used to rotate the turbine wheelwhich is housed in the turbinecasing. Turbine temperaturesup to 760 deg C

The turbine wheel is connectedto a common shaft which in turnrotates a compressor wheel.


As more gas passed throughthe turbine housing, the fasterthe turbine wheel rotates.

As the turbine wheel increases inspeed, so does the compressorwheel. This creates a sucking process and pulls air into the compressor cover from the atmosphere (filtered).

The faster the wheels spin the,the more air is sucked in.


As the air is sucked into the compressor cover, it is forcedthrough a diffuser area.

This compresses the air and forces it into the engine

This process causes the air to increase in temperature, up to 200 degrees C

How a turbochager works


The oil used in a turbocharger is the same as that used for your engine.

The oil is used as both a lubricantand a coolant.

The oil is fed under pressure intothe bearing housing, through thejournal bearings and thrust system.

Bearing System

Journal Bearings fully floating bearings - allows higher clearances, so higher oil

flows for cooling oil film thicknesses of 0.008 to 0.015 mm leaded bronze allow high degrees of imbalance

Thrust Bearing taper land bearing phosphor bronze or sintered iron thrust loads of 100 - 2000 N (size dependent) typical oil film thickness 0.008 - 0.015mm

Has to withstand high temperatures, hot shut down, soot loading in the oil, contaminants, oil additives, dry starts.

A wastegate mechanism functions, by allowing some of the exhaust gas to bypass the turbine thus limiting turbo speed & boost pressure.

Typically the wastegate valve is only opened at high engine speeds & loads (used to prevent turbo speed or boost pressure from exceeding safe levels).

Turbocharger Basics Wastegates

Wastegate Turbocharger

A typical wastegate mechanism consists of a flap valve mounted in the side of the turbine casing.

This is operated by a pneumatic actuator, attached to a control rod.

The actuator contains a return spring (which keeps the valve closed at low boost pressure) and a diaphragm which drives a piston on the end of the control rod.

Boost air (either directly from the engine, or via a control valve) is admitted to the cavity above the diaphragm.

When the boost pressure force exceeds the spring pre- load force, the piston pushes the control rod, which opens the wastegate valve.


Wastegate Mechanism: Actuator-linkage-valve

Wastegate Check

Apply 3 bar (300 kPa) air pressure to ensure that the wastegate actuator is not leaking or stuck.

Check for air leakage

What max. temperatures do we see at the

turbine end

A) 400 deg CB) 680 deg CC) 760 deg CD) 220 deg C

ANSWER C

QUIZ

Balancing

The Importance of Balance

Balancing: Introduction

To enable the bearing system to survive at the turbochargers high rotational speeds. HX25W 200k rpm = 3333 rev/sec H1C/HX35 140k rpm = 2333 rev/sec H1E/HX40 130k rpm = 2166 rev/sec H2/HX50 115k rpm = 1916 rev/sec

To increase the durability and lifetime of a turbocharger in service.

To reduce the noise emitted from the turbocharger.

To enable the turbo to meet the requirements of today's high performance diesel engines.

Balancing:

Why Balance?

Turbine Wheel Turbine Wheel NoseNose

Turbine Blade Tip

Balancing:

Component Balance

Turbine Wheel Turbine Wheel BackfaceBackface

Impeller NoseImpeller Nose

Impeller Impeller DiameterDiameter

BackfaceBackfaceBalancingComponent Balance

Turbine WheelTurbine Wheel ImpellerImpeller

Thrust SpacerThrust Spacer

Oil SlingerOil Slinger

LocknutLocknut

BalancingRotor Balance

Turbocharger Balancing

Very fine balancing of the rotating assembly of a turbocharger is critical, due to extremely high operating speeds (max speeds on some models are close to 200,000 rpm).High out-of-balance levels can lead firstly to increased noise, then reduced durability, and in extreme cases even early-life catastrophic failure.Traditionally, Heavy-Duty and Mid-Range turbochargers have relied on component balancing of the rotor elements (impeller, shaft & wheel, etc), followed by rotor-balancing (see below). Rotor balancing is usually low-speed (400rpm max.), hence does not induce any shaft bending due to imbalance couples or other dynamic rotor effects. It also uses solid metal rollers in place of the turbo bearings, hence also does not replicate the characteristics of the conventional turbo bearing system (elasticity, damping, hydrodynamics, etc).

Turbocharger Balancing

In order to reduce turbo-to-turbo variance, and satisfy our OE customers needs for ever-improving NVH requirements, Holset has moved from rotor-balancing, to core-balancing (see picture) on many of our products.This involves measuring the out-of-balance forces of a turbocharger or core assembly (assembled bearing housing & rotor components), typically air-jet driven. This runs at higher speeds (3000 to 5000 rpm). It includes some rotor & bearing system effects, but runs below the speed where oil-film damping will influence the results.Also, since a turbo which passes this test does not need to have its rotor touched again (unlike rotor-balanced units which have to be disassembled & reassembled into the bearing housing), then final product quality can be much more tightly-controlled.

Low Speed Core Balance process

Turbocharger BalancingHolset has implemented a further development of core-balancing, in which the turbocharger is run across almost its whole speed range, and has also been extended to single plane balance correction by metal removal on the impeller nut.This high-speed core-balancing is called VSR (Vibration Sorting Rig) at Holset. This has now become a requirement on some of our O.E. products, where very fine control of turbocharger noise levels is necessary, and is now standard practice on many of our Mid-Range products.[Note: While we are currently maintaining equivalent rotor-balance data for all turbos in our Service spec. sheets, this will probably become unacceptable on some models, in the near future].

High Speed Core Balance process

(VSR)

High Speed Vibration Measurement Method -

VSRManufactured by Turbo Technics in Northampton, UK.Approx 150 Turbo Technics VSR machine running within the turbo industry, primarily within pass car aftermarket, but now seeing demand within main line production also.Uses cold compressed air driveMeasures the once per rev turbine housing vibrationSpeed range up to 250,000rpm dependant on turbocharger model, max speed for Holset MR product is around 110,000 rpm

Mk IV Holset VSR machine

MkIV HSCB process (VSR) Holset Mid Range product WW - includes metal removal on impeller lock nut

HSCB metal removal & effects on

unbalance vs speedHY35 VSR Traces

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General Vibration SpecificationSensitive ApplicationVibration Specification

Vibration Level Before CorrectionVibration Level After Correction

Metal Removal on impeller nut Holset VSR

Rotor System Resonance Modes

Second Rigid Body ModeCylindrical Mode

First Rigid Body ModeConical Mode

First Flexural Mode

Relationship between

Unbalance & Speed

Unbalance phase angle

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1st Rigid Body Mode

2nd Rigid Body Mode

1st Flexural Mode

Turbocharger Failure Analysis

TURBOCHARGER FAILURE ANALYSIS

Turbocharger Failure Analysis

The purpose of analyzing a failed turbocharger is to determine the root cause of failure.

We also need to determine who is responsible.

We need to prevent a reoccurrence - whether it is a HOLSET problem or a customer / end user problem.

If the problem is HOLSETS we need to fix it.

If the problem is the customers we need to work with and support them, to ensure it doesnt happen again.

Reported Faults

Leak oilBrokenLow powerNoisyGas leakageSeizedHigh oil consumptionBroken shaftSmoke

How can we determine the root cause of the problem?

Disassembly & Inspection

Check for damage to the external surfaces,concentrating on the flange areas where incorrect fitting of pipes or adaptors, may have caused damage.


Check for compressor end foreign object damage by looking in theintake.

AIR INTAKE

Foreign Object Damage Compressor End

Damage to the blade tipsCause : Rags,wrenches,nuts,screws,parts from the intake filter.


Check the turbine intake for signs of solid objects. Note! Except in severe cases the turbine housing needs to be removed (in order to inspect the blade tips).

TURBINE INLET

Foreign Body Turbine End


Check the overall appearance corresponds with the data supplied. (i.e. claim data is 10,000kms, but turbo appears to have been in use for much longer .

Check axial and radial clearances. Clearances can be found in theHolset Service Data Sheet (current version can be downloaded from www.Holset.co.uk - Parts & Service section)


Remove the compressor housing

Remove the core assyfrom the turbine housing

Remove the turbine housing and compressor cover and check for any wheel touches or rubs on the profile.


Remove the compressor wheel and check for signs of excessive oil on the backface.This could be due to oil carryover past the compressor seal ring. Check condition of the seal ring when removed.The most common cause of oil leakage, is a blocked air intake filter.


Remove the shaft & wheel,check for any heat discolouration and any wear on the shaft.


Remove the circlip

Remove the oil seal plate

Remove the O-ring seal

Check for damage to the O-ring seal


Remove the oil slinger from the oil seal plate.

Check for wear or score marks in the bore.

Remove the seal ring


Remove the thrust bearing and thrust collar,check for blockage of the oil feed holes ( a common cause of thrust failure ). Check for heat discolouration and scoring marks of both the bearing and collar.

If excessive radial clearance was found it is likely that the journal bearings will also be damaged.

Silicone Applied to Oil Inlet Gasket

Do not use silicone

Foreign Body Blocking the Oil Supply to

the Thrust Bearing

Silicone blocking oil to the thrust bearing

Blocked Thrust Bearing

Foreign object blocking the oil feed to the thrust system

Cause :Silicone from the oilfeed pipe fitting.Cleanliness duringservice intervals,filters and oil.


Remove the compressor-end outer circlipand remove the journal bearing. Look for scoring marks on both the outside (OD) and inside (ID) diameters, this can be caused by oil contamination ( dirt ) in the oil.

Remove the turbine-end bearing. This bearing will normally be a much darker colour than the compressor bearing (due to higher operating temperature).

Oil Dirt Ingress

Cause : Service intervals overdueCleanliness during servicePoor quality oilPoor quality filters

Oil Dirt Ingress

Shaft wear from oil dirt ingress

Oil Contamination

New bearing Contaminated bearing

Check the colour of the bearing, a natural darkening with age is acceptable. A duller,powdery surface is an indication of engine coolant in the oil - the same appearance will normally also be found on the thrust bearing.

Oil Delay Bronze particleson the shaft

Causes :Restricted oil feed pipes.Low oil level in the sumpBlocked oil filterLong periods on Non useLack of priming

Oil Starvation

Cause : Oil pump failureBroken oil feed pipeNo oil in engine.

Hot Shutdown - Overheating

Cause: Hot shutdown of the engine, poor quality lub. oil, infrequent service intervals, check for heavy carbon deposit in the bearing housing.

Hot Shutdown

Check for sign of heavy carbon deposits in the bearing housing,on the shaft & wheel piston ring boss area. This can be the cause of hot shutdowns, lack of maintenance or poor quality oil.

Laquering of the shaft is also common in cases of hot shutdown failures.

Hot Shutdown - Overheating

Time (Time (secssecs))00 3603606060 120120 180180 240240 300300

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C Hot Shut DownHot Shut Downfrom Peak Torquefrom Peak Torque

3 min Idle3 min Idle

2 min Idle2 min Idle

1 min Idle1 min IdleTemp Limit of Temp Limit of CD OilCD Oil

Failure Diagnosis:Hot Shutdown

Excessive Engine Temperatures

Delamination of thedividing wall and erosion of the gas entry.

Turbine housing cracked.

Cause : Incorrect fuel/air ratio, caused by blocked airintake filter, or overfuelling, etc.

Oil Leakage

External - Common Causes :

Loose / Damaged oil inlet and oil drain fittings.

If fitting a new gasket and tightening the fittings does not stop the leak,then look for a damaged oil line or leaking centre housing.

Internal Compressor & Turbine - Common Causes :Restriction in the turbo oil drain will force oil past the split ring seals at both the turbine and compressor ends.Oil leakage at both ends simultaneously is a good indicator that this may be the problemEngine blow by pressure - which can be due to the engine crankcase vent being blocked by damage,plugging or icing.

Oil Leakage - Compressor

THIS WILL NOT DAMAGE THE TURBO UNLESS THE THRUST BEARING FAILS.

Typical cause is a blocked air intake filter or collapsed intake pipe.

Compressor End Oil Leakage

Oil Leakage

Balance - Related Failures

Balance failures due to a manufacturing problem (hence Holset Responsibility) usually occur in very early life. (i.e. most within 500 km).If a balance failure occurs in late life - it is normally caused by wheel foreign-object damage, turbo overspeed or tampering)

Balance failure causes: Parts misalignedRotor parts replaced without check-balancingIncorrect parts used.

Noise

Causes of noisy turbo complaints High level of rotor imbalance

(if very early life - i.e. less than 1k km, most likely a Holset issue - if later in life, look for foreign-object damage or bearing damage which caused a wheel rub, etc).

Turbocharger bearing housing joints - loose screws, V clamps. (A/Mktturbos fitted,OE orientation factory set ).

Check for signs of leakage/damaged jointing surfaces.

Air or exhaust leaks on external turbo flanges Look for soot on the turbine inlet and exhaust flanges, check if

fasteners are loose , or surfaces damaged.

Non-turbocharger issues (water pump, fan belt, etc, etc).

Oil Leakage

WARNING - DO NOT operate the engine if you suspect any oil has collected in the engine intake or charge cooler.Drain and clean before engine start up to avoid engine runaway after full warm up

Any Questions?

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Special Turbo Training

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Transcript of Special Turbo Training