How Foil Bearings Work The motor/rotor shaft is supported radiallytwo journal bearings and axially by two thrustbearings. As the shaft rotates, a wedgeformed due to the radial displacement ofshaft. Hydrodynamic action draws the workinggas into the wedge where it is locallycompressed. The pressurized section providessupport for the shaft while the layers ofprovide the compliant features of the bearingAs the shaft speed increases, a hydrodynamicfilm of gas is produced that forces the shaftlift off and become airborne eliminating anycontact between the shaft and the bearing.

Blowers with

Typical Foil Bearing

Blowers with Advanced Foil Bearings Provide HIGHER EFFICIENCY – Foil bearings allow

operation at high speeds, thus achievingimproved aerodynamic efficiency.

HIGHER RELIABILITY – Foil bearing

machines require no lubrication, and similarmachines for aircraft have demonstratedreliability up to more than 100,000 hoursoperation.

COMPACT SIZE – The ability to operate

reliably at high speed allows designs tolightweight and very compact.

OIL FREE – Foil bearing machines are

completely oil-free, and hence environmentallyfriendly.

LOW NOISE & VIBRATION – Foil bearings

provide low noise and low vibration due tometal-to-metal contact.

NO SCHEDULED MAINTENANCE – Foil

bearings do not require lubrication, resultinglower operating costs.

WIDE TEMPERATURE RANGE (4K1,255K) – Foil bearings do not encounter

problems lubricants typically cause : breakingdown at very high temperatures and becomingtoo viscous at low temperatures.

Cover Picture : High-Temperature Anode Gas Recycle Blo

R&D Dynamics Corporation designs,

develops and manufactures a complete

range of high-speed oil-free fuel cell

blowers supported on foil air/gas bearings.

As a core technology provider to the SECA

(Solid State Energy Conversion Alliance),

R&D Dynamics Corporation has been

providing high-efficiency, high-reliability,

maintenance-free, oil-free fuel cell blowers

for cathode, anode, fuel and recycle

applications.

bythrust

wedge isthe

workinglocally

providesfoil

bearing.hydrodynamic

shaft toany

High Efficiency Achieved FromOptimized Aerodynamic Blower Design

– Blower blade geometry is optimized for

high speed operation with foil bearings and

motor. Computational Fluid

Dynamics (CFD) is applied to achieve

highly efficient flow path and bladeprofiles.PMSM(Permanent Magnet SynchronousMotor) – R&D Dynamics’ PMSM provideshigher efficiency, smaller volume andhigher power density in high-speedapplications.Sensorless PMSM Drive – R&D

Dynamics’ PMSM drive provides an

Advanced Foil Bearings Provide allow

achieving

bearing

similardemonstrated

hours of

operate

be

are

environmentally

bearings

no

Foil

resulting in

tothe

breakingbecoming

Dynamics’ PMSM drive provides anoptimized sensorless vector control withhigher efficiency and compact size.

Optimized blade design using CFD

Blower

PMSM magnetic circuit design using Finite Element Analysis

the high-speed

BearingsAll fuel cell blowers come equipped withstate-of-the-art foil air/gas bearings. R&D

Dynamics Corporation has decadesexperience building high-speed turbomachinerysupported on foil bearings. Bearings aredesigned and manufactured in-house usingproprietary methods. All foil bearings are testedon journal and thrust bearing test rigs.

Performance Focused Engineering

Finite Element Analysis (FEA)All fuel cell blower designs areevaluated using FEA software. High

rotational speeds demand careful attentionstresses in the rotating assembly. In addition,rotor dynamics must be properly analyzed

Computational Fluid Dynamics(CFD) -Aided DesignAll fuel cell blower aerodynamic designsare completed using CFD analysis. High

efficiency blower geometry is obtained by usingproprietary in-house design methods whichhave been correlated with test data. CFDanalysis finalizes aerodynamic design to obtainoptimized blower flow paths and blade profiles

rotor dynamics must be properly analyzedprevent unwanted shaft critical speeds.

Testing and Design CapabilitiesAll fuel cell blowers are qualificationtested to verify adherence to strictdesign criteria. Performance is measured

using approved procedures and standardsVibration and shaft displacement are monitoredduring qualification testing to ensure longand high reliability.

High-Temperature Recycle BlowerR&D Dynamics Corporation offers hightemperature recycle blowers supportedon foil gas bearings.• Gas temperature can be as high as 850°C.• Blowers are corrosion resistant.• Motor is hermetically sealed.• Heat leakage is minimized.

Motors and DrivesAll fuel cell blowers are driven by highefficiency PMSM and sensorless drivesHigh-speed and high-efficiency PMSM andsensorless drives are designed and fabricatedin-house using proprietary methods. All motorsand drives are tested on component test rigsbefore blower assembly.

withR&D

ofturbomachinery

areusing

tested

Performance Focused Engineering

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attention toaddition,

analyzed to

Dynamics

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obtainprofiles.

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Capabilitiesqualification

strictmeasured

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supported

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R&D Dynamics Blower Models

Corrected ٭ inlet conditions : 1 atm, 15°C

*

*

high-

drives.and

fabricatedmotors

rigs

R&D Dynamics Corporation applies state-of-the-

art Computer-Aided Design and Manufacturing

(CAD/CAM).

High efficiency compressors, turbines and fans are

manufactured in-house using CNC Lathes and 5-axis Milling Machines. Other parts such as shafts,foil bearings and seals are also manufactured in-house. Outside approved subcontractors are usedfor specialized processes such as heat treatmentand plating.

Manufacturing

Quality Quality R&D Dynamics Corporation isISO 9001:2000 / AS9100 certifiedand registered.T h e in s p e c t io n s y s te m isapproved by the FAA (FederalAviation Agency). We have state-of-the-art inspection equipmentinc lud ing com pute r-con tro lled

Coordinate Measuring Machines

(C M M ) in te m p e ra tu re a n d humidity monitored rooms.

E-mail UsIn order to design and manufacture fuel cell

blowers for your specific needs, please e-mail

mktg@rddynamics.com

with the following information :

• Gas Type (including Component Mol%)• Inlet Pressure• Inlet Temperature• Gas Flow Rate• Pressure Rise (or Outlet Pressure)

Customer Satisfaction

49 West Dudley Town Road

Bloomfield, CT 06002-1316Tel.(860)726-1204 Fax.(860)726-1206

www.rddynamics.com

Copyright © 2009 R&D Dynamics Corp. All Rights Reserved.