airfoil bearings
DESCRIPTION
Presentation on airfoil bearings for high speed machinery.TRANSCRIPT
-
Air Foil Bearing
2011
Neuros Co., Ltd
-
2 Turbo Energy R&D Center
Air Foil Bearing
Air film is generated automatically by the hydrodynamic interaction between
viscous fluid and foil structure in a rotating sleeve.
Elasto-Hydrodynamics : Elasticity + Reynolds Eqn. for Lubrication
Running Air Film Thickness : 5 ~ 20 m
Application : Oil-Free Small & High Speed Rotor
Principle of Air Bearing Hydrodynamic Pressure Generation
U
Pressure Distribution
Velocity Distribution
-
3 Turbo Energy R&D Center
Applied Configuration
Bump Type : 2 Journal Bearings + 2 Thrust Bearings
Journal Bearings : Rotor Weight + Unbalance Load + Instability Operability
Thrust Bearings : Thrust Load + Tip Clearance Control + Power Loss Performance
Journal Bearing Thrust Bearing
-
4 Turbo Energy R&D Center
Principle
Elasto-Hydrodynamics
Semi-Empirical Method
Iterative Solution
Relaxation Factor
Hydrodynamics Reynolds Eqn Compressible Viscous Fluid Dynamics FDM : Nonlinear Pressure Distribution Geometry (by Elastic Deformation of Top Foil)
Elasticity Beam or Plate Theory Linear Elastic Deformation FEM Foil Deflection Force (by Pressure from Hydrodynamics) Journal Bearing Thrust Bearing
-
5 Turbo Energy R&D Center
Elasticity of Foil Structure
Top foils are supported by bump springs
Top foil : Geometry for hydrodynamics
Bump foil : Considered as spring with
Foil structure is designed to be in elastic range of
material Infinite life with normal operation
Bk
Top Foil
Bk E
EI
L
Bump Foil
i+1uuiiu' u'i+1
ff
m i+1m i
i+1i
Strain,
Stress,
Limit
2 (30%)
1: Rotor Weight
Limit : Elastic Range
2 : Max. Value in Running
1 (10%)
FEM Analysis of Bump
-
6 Turbo Energy R&D Center
Advantages of Air Foil Bearing
Noncontact Bearing Long Life / No. Scheduled Maintenance
Improved Performance : Low Power Loss
Low Noise and Vibration
Oil-Free Higher Reliability : Simple, No Oil Lub. System
System Weight Reduction : over 15% of Total Weight
Soft Failure : Easy to Replace
High Speed Operation : ~ 4 million DN (Others ~ 1 million DN)
Environmental Durability Low and High Temp. : Cryogenic ~ 650 C
Process Fluid Operation : Air, Neon,Helium, Xenon, Refrigerants, Liquid Oxygen, Liquid Nitrogen
More Stable Rotor Structure Larger Bearing Journal Size : D 40mm at 100,000 RPM
Increase Stiffness Property of Rotor
Bigger Critical Speed Margin
-
7 Turbo Energy R&D Center
Comparison with Other Bearings
High DN Number : D (Diameter in mm) x N (RPM)
Reliable, Long Life, Simple, and Environment-friendly
Rolling Element Bearing
Small
Low Loss
High Load
Noisy
Short Life
Limited DN
Aero Engine
Small Machine
Fluid Film Bearing
Long Life
Low Vibration
Hydrodynamic
Complex
High Loss
Limited DN
Industrial Machine
Air Foil Bearing
High Speed
Simple/Oil-less
Low Loss
Low Load
Coating
Small Rotor
ACM
Small Machine
-
8 Turbo Energy R&D Center
Rotordynamics using Air Foil Bearing
106
107
108
0
10000
20000
30000
40000
50000
60000
Ball Bearing
Air Foil Bearing
Ro
tati
on
al S
peed
, R
PM
Supports Stiffness, N/m
79%
7%
Operating Range
1st
2nd
3rd
Ball Bearing
Industrial Turbo Machine : Motor + Compressor + Turbine
Stable Critical Speed Design with Air Foil Bearing
Air Foil Bearing
-
9 Turbo Energy R&D Center
Application of Air Foil Bearing
ACM for ECS (Cabin Pressurizing/Avionics Cooling)
Small / High Speed Rotor :
-
10 Turbo Energy R&D Center
Application to Industrial Machines
Applied to Various Turbo Machines: ~ 100,000 RPM, ~ 600 C
Turbo Blowers with High Speed Motor : Advanced Application
20000 40000 60000 80000 100000 1200000
20
40
60
80
100
Potential Region
Jo
urn
al B
eari
ng
Dia
mete
r (m
m)
Rotor Speed (RPM)
Turbo Blower
Turbo Compressor
Microturbine
Cryocooler
Pathfinder
Region I
Region II
Region III
Region I : Conventional ACM, Turbo Expander Mircroturbine
Region II : Medium Turbo Compressor Microturbine
Region III : Advanced Turbo Blower
-
11 Turbo Energy R&D Center
Developed Air Foil Bearings
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6
Application Turbo Blower Cryocooler Micro Turbine NRL Motor Compressor for PEM FC
ACM for
Aircraft
Power 30 ~ 300 hp 38 kW 65 kW 200 kW 15kW Cooling 2kW
Motor PMSM PMSM PMSM PMSM PMSM -
RPM 17,000~60,000 100,000 61,300 70,000 96,000 60,000
Journal Dia. 40~90 mm 40 mm 50 mm 60 mm 25 mm 25 mm
Rotor Mass 3~26 kg 2.6 kg 12 kg 8.6 kg 0.9 kg 0.6 kg
DN 3.6 million 4 million 3 million 4.2 million 2.4 million 1.5 million
Temp. ~ 200 C ~ 200 C ~ 600C ~ 200 C ~ 200 C ~ 200 C
Fluid Air, Gas Air, Gas Air Air Air Air
-
12 Turbo Energy R&D Center
Features
Motor : 50 ~ 300 HP
PD : 0.3 ~ 1.0 kgf/cm2
TD : 58 ~ 106 C
High Efficient Compressor
High Speed Motor/Inverter
Air Foil Bearing
Cooled by Itself
Sewage Treatment
Pneumatic Conveying
Air Supply for
Chemical Process
Ventilation
Cooler
Application 1
-
13 Turbo Energy R&D Center
Application 1
-
14 Turbo Energy R&D Center
Application 2
PMSM for Neon Compressor
38 kW at 100,000 RPM
Gas Foil Bearing
-
15 Turbo Energy R&D Center
Application 3
Cogeneration System using a Microturbine : 65 kW
Life : 30,000 hrs (Time Between Overhauls)
Noise : 65dB @10m
-
16 Turbo Energy R&D Center
Application 3
Vibration Free Rotor System
Oil Free System Air Foil Bearing
Flexible Coupling Design
Critical Speeds
1st 2nd 3rd 4th 5th
Analysis 11,760 12,150 15,160 19,387 140,260
Experiment 10,300 10,650 14,970 17,970
(RPM)
Flexible Coupling Mircroturbine Rotor Assembly
-
17 Turbo Energy R&D Center
Application 4
Micro Air Compressor for PEM Fuel Cell
15 kW @ 96,000 RPM
Operating temperature : -20C to 50C
-
18 Turbo Energy R&D Center
Application 5
ACM for Aircraft POD
Cooling Capacity 2 kW
40,000 ~ 60,000 rpm
-
19 Turbo Energy R&D Center
Air Foil Bearing Test Rig 1
Journal Bearing Test Thrust Bearing Test
Air Turbine Driven : ~ 30,000 RPM
Loading by Pneumatic Device : ~ 80 kgf
Journal & Thrust Bearing Test
-
20 Turbo Energy R&D Center
Air Foil Bearing Test Rig 2
Motor Driven : ~ 120,000 RPM
Loading by Pneumatic Device : ~ 30 kgf
Journal & Thrust Bearing Test
Journal Bearing Test Thrust Bearing Test
-
21 Turbo Energy R&D Center
Air Foil Bearing Test Rig 3
Motor Driven : ~ 42,000 RPM
Loading by Pneumatic Device : ~ 80 kgf
High Temperature Environment : ~ 600 C
High Temp. Test
-
22 Turbo Energy R&D Center
Air Foil Bearing Test Rig 4
On/Off Test for Endurance of Coating : 20,000 Cycles
Rotor Mass : 2.6 kg
Motor Driven
Automation Using LabView
On/Off Test
-
23 Turbo Energy R&D Center
Endurance Test Results
Vibration (Shaft Disp.)
Journal Bearing Surface Shaft Surface
RPM Profile
-
24 Turbo Energy R&D Center
Air Foil Bearing Test Rig 5
Rotor-Bearing Simulator : Air-lubricated, Rotor Mass 13.2 kg
75kW Motor(PMSM) with Inverter : Accurate Speed Control
Axial Loading Mechanism : Pressurizing on Rotating Disk
Power Loss Evaluation by Temperature & Cooling Flow Rate
Max. 30,000 RPM and 100 kgf
Air Foil Thrust Bearings
Cooling Air In
Pressurizing Chamber
Cooling Air Out
High Speed Motor
Air Foil Journal BearingsLabyrinth Seal
LM
Guide
Pressurinzing Air In
Load Cell
Rotor-Bearing Simulator
-
25 Turbo Energy R&D Center
Air Foil Bearing Test Rig 6
Rotor-Bearing Simulator : Air-lubricated, Rotor Mass 26 kg
223kW Motor(PMSM) with Inverter
Axial Loading Mechanism
Max. 25,000 RPM and 100 kgf
Rotor-Bearing Simulator
-
26 Turbo Energy R&D Center
Lift Off Speed of Journal Bearing
Rotor Mass : 14.7 kg
Lift Off Speed : 2,000 RPM
-
27 Turbo Energy R&D Center
Endurance at Field Operation
50hp Turbo Blower : Steel Company
Field Operation : 20,000 On/Off
Cycles
-
28 Turbo Energy R&D Center
Endurance Test of FC Compressor
20hp Compressor for PEM FC
1,000,000 On/Off Cycles
-
29 Turbo Energy R&D Center
Blower : Low Pressure Compressor
Pressure Ratio : 1.3 ~ 2.0
Type
Positive Displacement Blower : Roots
Turbo Blower : Gear Box Type / High Speed Motor
Efficiency, Maintenance, Noise : Roots Type Turbo Type
Application
Air Supply : Waste Water Treatment, Power Plant Desulfurization
Raw Power Transportation : Cement Industry, Petrochemical Industry
Ventilation / Cooling / Vacuum
Roots Blower Turbo Blower
-
30 Turbo Energy R&D Center
Applications of Blower
3 ~ 10 m
Air
Blower
Waste Water Treatment
Aerobic microorganisms dissolve contaminants by blowing air into sewage
-
31 Turbo Energy R&D Center
Turbo Blower Gear Driven Turbo Blower
Low Speed AC Motor
Coupling + Gear Box + Compressor
Fluid Film Bearing
Large & Complex
Oil System & Cooling System
Periodical Maintenance (G/B, Coupling,Bearing)
High Speed Turbo Blower
High Speed Motor
Single Rotor : Compressor + Motor
Air Foil Bearing
Small & Simple
Oil Free System
Maintenance Free
-
32 Turbo Energy R&D Center
Dr. Dellacorte(NASA) visit (2007.9 / 2010.9)