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Ball Bearing Turbocharger – Technology development Christopher Mitchell
Ball Bearing Turbocharger –
Technology development
Christopher Mitchell
Schaeffler Symposium 2014 Christopher Mitchell 1
Introduction
Megatrend
Legislation
95 g/km in 2020
Commercial
Oil price, Cost minimisation
Consumer
Performance and Efficiency
Average CO2 Emissions Drivers
CO2 Reduction /
Efficiency Improvement
Schaeffler Symposium 2014 Christopher Mitchell 2
Development Target
Schaeffler Symposium 2014 Christopher Mitchell 3
Sub-Trends & Main Technologies
Megatrend
CO2 Reduction /
Efficiency Improvement
Legislation
95 g/km in 2020
Commercial
Oil price, Cost minimisation
Consumer
Performance and Efficiency
Drivers Average CO2 Emissions
Schaeffler Symposium 2014 Christopher Mitchell 4
Sub-Trends & Main Technologies
Main Technology
Down-Sizing Down-Speeding Driving Resistance Comprehensive
Measurements
Subtrends
￭ Thermal Management
￭ Electrification Ancillary
Components
￭ Lightweight
Construction
￭ Low Friction
Lubrication / Materials
￭ Low rpm provision of
power
￭ Optimised
Transmission e.g.
￭ Continuously
Variable
Transmission
￭ Dual Clutch
Transmission
￭ Forced Induction/
Boosting
￭ Stratified DI / HCCI
￭ Variable Valve Train
Megatrend
CO2 Reduction /
Efficiency Improvement
Schaeffler Symposium 2014 Christopher Mitchell 5
Forced Induction Concepts
Schaeffler Symposium 2014 Christopher Mitchell 6
Forced Induction
Gottlieb Wilhelm Daimler (1824 – 1900) Patent DRP 34926 1885
Grandfather Clock Design
[Utilising Gear Driven Precompression]
Schaeffler Symposium 2014 Christopher Mitchell 7
Turbocharger - Origin
Alfred Büchi (1879-1959) Patent CH 35 259A 1905
Exhaust Driven Precompression
Schaeffler Symposium 2014 Christopher Mitchell 8
Ball Bearing Guided Turbo Charger
Schaeffler Symposium 2014 Christopher Mitchell 9
Schaeffler Ball Bearing Cartridge
Anti-Rotation Slot
Squeeze Film Land
Oil Jet
Ceramic Balls
Metallic Cage
Turbine Inner Ring
Outer Ring Compressor Inner Ring
Schaeffler Symposium 2014 Christopher Mitchell 10
Stationary Ball Bearing Benefits F
riction p
ow
er
loss [
W]
Speed [Hz]
Operational Power Loss of Bearing System
400 600 800 1000 1200 1400 1600 Sourc
e: H
oneyw
ell
Tu
rbo T
echnolo
gie
s
Plain bearing
Ball bearing
~50% reduction
Schaeffler Symposium 2014 Christopher Mitchell 11
Transient Ball Bearing Benefits
Sourc
e: H
oneyw
ell
Tu
rbo T
echnolo
gie
s
Plain bearing Ball bearing Plain bearing Ball bearing
Schaeffler Symposium 2014 Christopher Mitchell 12
Friction Mechanisms
Film Bearing Rolling Bearing
Schaeffler Symposium 2014 Christopher Mitchell 13
Flow Regimes
Optimally Flooded Completely Flooded
Schaeffler Symposium 2014 Christopher Mitchell 14
Optimial Lubricant Flow
Completely Flooded
Optimally Flooded Power Loss [W]
Schaeffler Symposium 2014 Christopher Mitchell 15
Turbo Charger Cartridge Power Loss
0
10
20
30
40
50
60
min.
measurement
max.
measurement
analysis
Po
wer
loss [
W]
viscous friction
circumferrential gap
load dependent
friction
catalogue
supplement for fully
floodedcatalogue speed and
viscocity
experiment (max)
Schaeffler Symposium 2014 Christopher Mitchell 16
1-D Fluid Dynamics
Investigation on Lubricant Availability throughout Operating Conditions
Optimization of Lubricant Supply Paths
Oil Jets into Bearing
Squeeze Films
Oil Drain
1-D Simulation Model Investigated Geometry
Schaeffler Symposium 2014 Christopher Mitchell 17
Dynamic Bearing Behaviour
Contact Forces Differential Speed
Contact Pressure Contact Angle
Schaeffler Symposium 2014 Christopher Mitchell 18
CABA3D – Bearing Interior Dynamic Simulation
Ball and Cage Dynamic Behavior
Contact Forces (vs. Race and vs. Cage)
Spin/Roll; Ball Excursion, …
Shaft displacement y
Shaft d
ispla
cem
ent
z
Schaeffler Symposium 2014 Christopher Mitchell 19
BEARINX – Linear Rotor Dynamics
Eigenmodes
Eigenfrequencies
Campbell Diagrams Shaft speed
Eig
en
fre
quen
cie
s
x
y
z x
y
z
Schaeffler Symposium 2014 Christopher Mitchell 20
FEA and Multi-Body-Structure
Modal Reduction for the Simulation Platform
Pre-Tension Force
Axial Contact
Installation Effects
Contact & Centrifugal Forces
Schaeffler Symposium 2014 Christopher Mitchell 21
Schaeffler Simulation Platform – System Dynamics
Fully Integrated Development Process
￭Direct Integration of Nonlinear BEARINX Subsystem into Full System Dynamic Model
￭ Component Know-How vs. System Know-How
BEARINX®
Waterfall Diagram Simulation Platform
Schaeffler Symposium 2014 Christopher Mitchell 22
Combined FEM-CFD Analysis
CFD Model
FEM Model
Schaeffler Symposium 2014 Christopher Mitchell 23
Temperature of Bearing Parts
Tem
pera
ture
Schaeffler Symposium 2014 Christopher Mitchell 24
Real World Data
￭ Applicable to existing hardware
￭ Compatible with low viscosity
engine oil
￭ Cold start improvement + 80%
￭ Drive away torque improved
￭ Transient response - 41%
to boost
@ 1500rpm
￭ Engine rated power increase + 5%
￭ Engine torque increase + 10% @ ISO soot
￭ "Kick-down" performance + 2%
Data source: Honeywell
Fuel Economy Performance
Performance Convenience
￭ Friction power loss - 50% in the bearing system
￭ Fuel consumption - 2.5% (dir. cor. to CO2
emission)
Schaeffler Symposium 2014 Christopher Mitchell 25
Summary
Main Technology
Down-Sizing Down-Speeding Driving Resistance Comprehensive
Measurements
Subtrends
￭ Thermal Management
￭ Electrification Ancillary
Components
￭ Lightweight
Construction
￭ Low Friction
Lubrication / Materials
￭ Low rpm provision of
power
￭ Optimised
Transmission e.g.
￭ Continuously
Variable
Transmission
￭ Dual Clutch
Transmission
￭ Forced Induction/
Boosting
￭ Stratified DI / HCCI
￭ Variable Valve Train
Megatrend
CO2 Reduction /
Efficiency Improvement
~ + 5% Power increase
~ + 20% Torque increase
~ - 2.5% CO2 Emission
Superior cold start behaviour
Superior transient response
Turbocharger Ball Bearing
We can't solve problems by using the same kind of thinking
we used when we created them.
” ‟
Albert Einstein
1879-1955
[Turbo charging is,] briefly spoken,
open the throttle today, are ready to go tomorrow.
” ‟
Walter Röhrl
Rallye Champion
1980 and 1982
