VespelOnly by DuPont

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® DuPont registered trademarkAU

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VESPEL®

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ContentsVespel® parts and shapes 5

Properties 6-7

Properties into benefits 8-9

Transmissions 10 -11

Electrical motors 12 -13

Brakes 14

Fuel systems 15

Turbo chargers and exhaust gas return systems 15

Other equipment 16

Opportunities 17

Summary of typical properties of Vespel® SPPolymide Resins 18

The Vespel® offering 19

VESPEL®

Under bonnet

• Fuel systems•Turbocharger• EGR• Vacuum pumps• Ignition• Starter• Belt tensioner

Transmissions

• Automatic gear boxes• Clutches

3

Electrical motors

• Window lift• Windscreen wiper• Sunroof• Wing mirror adjuster• Seat adjuster• Steering wheel height

adjuster

Brake systems

• ABS• Wear pad sensors

4

Global company

Finished-parts supplier

Proven applications intransmissions andelectrical motors

ISO 9001 certified and several customer

certifications

Cost effective andinnovative design

Continuous R&Dinvestment

More than 15 years in the automotive

industry

Understanding of technical, quality andsupply requirements

Testing facility for seal rings, bushings

and washers

Partnership with car manufacturer

suppliers

Specialists in wear and friction

components

VESPEL® PARTS ANDSHAPES

VESPEL®

5

PROPERTIES...

Excellent compressive properties

- High elastic limit- Non brittle- High deformation capability

Insulation

- Thermal- Electric

Wear and friction problemsolver

- Low CF- Low wear rate- Constant CF

Machinability

- Similar to brass- Quality 7 tolerances achievable

Chemical compatibility

- With oil- With solvents- With fuels (diesel/gasoline)

Temperature resistance

- No melting point- No Tg- Continuous use 290°C, excursions to 480°C

Polymer

- Light weight- Dampens vibration

Impact resistance

High PV capability with orwithout lubrication

- PVvalue (dry) = 12 MPa m/s- PVvalue (lubricated) = 40 MPa m/s- Instantaneous PVlimit (lubricated) = 140 MPa m/s

Electrical insulation

- Parts retain their good electricalproperties at high temperatures

...I

NT

O B

EN

EF

ITS

Tem

pera

ture

resi

stan

ce

- No

mel

ting

poin

t- N

o Tg

- Con

tinuo

us u

se 2

90°C

, ex

curs

ions

to 4

80°C

Po

lym

er

- Lig

ht w

eigh

t- D

ampe

ns v

ibra

tion

Imp

act

resi

stan

ce

Hig

h P

V c

ap

ab

ility

wit

h o

rw

ith

ou

t lu

bri

cati

on

- PV

valu

e (d

ry) =

12

MP

a m

/s- P

Vva

lue

(lubr

icat

ed) =

40

MP

a m

/s- I

nsta

ntan

eous

PV

limit

(lubr

icat

ed) =

14

0 M

Pa

m/s

- W

ork

s su

ccess

fully

in

th

eh

ott

est

are

as

of

the e

ng

ine

- W

ith

stan

ds

all

car

ass

em

bly

pro

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es

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an

be o

verm

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lded

- S

afe

ty

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eig

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ts

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ois

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ed

uct

ion

- S

uit

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or

hig

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req

uen

cyvib

rati

on

- R

esi

sts

imp

act

- C

an

ru

n w

ith

ou

t lu

bri

cati

on

- R

ed

uct

ion

of

con

tact

are

a,

i.e. p

art

siz

e

- In

crease

d s

afe

ty m

arg

in in

case

of

mis

use

- P

art

s w

ill r

un

dry

sh

ou

ld

lub

rica

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n f

ail

- Lo

wer

warr

an

ty c

ost

s

Ele

ctri

cal in

sula

tio

n

- Par

ts re

tain

thei

r goo

d el

ectri

cal

prop

ertie

s at

hig

h te

mpe

ratu

res

6

PR

OP

ER

TIE

S..

.

- E

asy

ass

em

bly

- N

o b

reakag

e

- S

ealin

g c

om

plia

nce

- C

an

pro

tect

oth

er

com

po

nen

ts

- Lo

ng

er

life

- R

elia

bili

ty

- R

ed

uce

d p

ow

er

con

sum

pti

on

- R

ed

uce

d w

arr

an

ty c

ost

s

- Fast

pro

toty

pin

g

- C

om

ple

x g

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metr

ies

an

d t

igh

tto

lera

nce

s ach

ievab

le w

ith

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nd

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mach

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g

- N

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orr

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on

- W

ork

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ccess

sfu

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co

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ctw

ith

all

au

tom

oti

ve c

hem

icals

Exce

llen

t co

mp

ress

ive

pro

pert

ies

- Hig

h el

astic

lim

it- N

on b

rittle

- Hig

h de

form

atio

n ca

pabi

lity

Th

erm

al in

sula

tio

n

- Can

pro

tect

oth

er c

ompo

nent

s

Wear

an

d f

rict

ion

pro

ble

mso

lver

- Low

CF

- Low

wea

r rat

e- C

onst

ant C

F

Mach

inab

ility

- Sim

ilar t

o br

ass

- Qua

lity

7 to

lera

nces

ach

ieva

ble

Ch

em

ical co

mp

ati

bili

ty

- With

oil

- With

sol

vent

s- W

ith fu

els

(die

sel/g

asol

ine)

In the last few decades, automaticgearboxes and transmissions haveincreasingly replaced manual devicesin cars, trucks, tractors and off-roadvehicles.

Driving comfort, optimization ofengine torque output, fuel saving andnew pollution regulations have nowbecome the driving force in the auto-motive industry.

Thrust washersWith its very high PVlimit of 12MPa.m/s in dry conditions coupledwith good compressive properties,Vespel® has been successful in appli-cations such as thrust washers inhydraulic transmissions and also insplit flywheels (clutches) coupledwith manual gearboxes. Vespel®

washers (with outside diameters ofup to 90 mm) have proved theirsuperior performance in tractor, truckand car transmissions by working in anormal oil mist environment andreaching PVs of up to 40 MPa.m/sand speeds of 7000 rpm. They caneven accept instantaneous PVs of 140MPa.m/s during gear changes in aforced lubrication environment.

The flexibility of Vespel® means thatwhen the loading and speed condi-tions are known the design can opti-mize contact area (outside and insidediameters). Features can also beadded to centre the part or to preventrotation in order to select the slidingsurface.

The design of hydraulic units is com-plex as it has to take into considera-tion such aspects as: leakage control,sealing, vibrations, high loads &speeds, high temperatures generatedby friction, durability and reliability.In certain extreme conditionsmechanical components, normallylubricated by the surrounding oil,may have to run dry, generatingexcess heat and leading to failure.

The introduction of Vespel® as wearand friction components such asThrust Washers, Seal Rings andValve Seats, has increased both per-formance and lifetime. At the sametime overall costs can be reduced by:

• easier assembly of seal rings

• elimination of forced lubrication

• elimination of heat treatment onmating material

• wider tolerances on machined mating surfaces

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VESPEL®

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Radial grooves, which can be manu-factured without additional machining,facilitate lubrication and thereforeincrease PVlimit. Vespel® thrustwashers resist static load without creepand impacts, and avoid the seizingoften seen with metal/metal solutions.

Seal ringsVespel® seal rings operating inside thetransmission work dynamically,mainly in the radial direction but alsosometimes in an axial linear direction.Their function is to provide a sealbetween the shaft and the housing atgiven pressures and speeds so thatclutches, i.e. gears, can be actuated.

A small leakage is neverthelessrequired here in order to lubricateother components such as needlebearings and gears, and also to avoidhigh surface temperatures. Lifetimeand reliability are very important as they both influence the shifting operations.

Vespel® seal rings are designedaccording to customers requirementsof speed, pressure, temperature,desired leakage rate, mating materialand allowable wear.

Some of today's existing and provenVespel® applications are:

• Tractor transmissions at speeds ofabout 2,500/3,000 rpm diameters upto 80 mm and pressures of 12 bars.

• Passenger car automatic gearboxesat speeds of 7,000 rpm for diametersup to 52mm and pressures of 12 bars.

• Automotive continuous velocitytransmissions (CVT) at speeds up to10,000 rpm for diameters about20mm and pressure of 20 bars.

Valve seatsThe reduction and control of oil leak-age within the transmission is animportant issue. The sealing compli-ance and resilience properties of

Vespel® make it the ideal material forvalve seats. They can be easily press-fitted into the housing and can elimi-nate the need for an "O" ring.Operating successfully in pressures of20 MPa, Vespel® valve seats havedemonstrated a high level of resis-tance to the abrasive action of metalparticles in dirty hydraulic oil whileproviding a reliable sealing perfor-mance over time while resistingimpact.

Seal ring gap type and dimensionsare calculated to provide appropriateleakage at the given temperatures andpressures. Wear can be minimized byoptimizing the contact area. With theiroutstanding chemical and creep resis-

tance,Vespel® seal rings are neitherattacked by hot oil nor extrudedbetween shaft and housing due topressure and heat.

Compared to other materials theassembly of Vespel® seal rings is easyand can be automated. The inherentflexibility of Vespel® makes seal ringseasy to open without breakage whileits toughness avoids deformationwhen inserting on the shaft.

With hydraulic pressure, seal ringswill then conform to the housing,without creeping, to provide sealing.

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Parts such as bushings, washersandthrust plugsworking in electricalmotors have to withstand axial andradial loads coupled with speed.

The wear and friction characteristicsof Vespel® have helped electricalmotor manufacturers to simplify theirdesign while improving performanceand life.

The search for comfort and safety in the automotive industry has lead toincreased numbers of electric motors.

These are now widely used to makedriving more pleasant (window lift,sunroof, central locking, air condi-tioning actuation, seat, mirrors & steering adjustment) and safer (windscreen wipers, idle and exhaustcontrols, differential locking).

Increasing regulations and specifica-tions for equipment such as starter-motors and fuel pumps place greaterdemands on mechanical wear andfriction components.

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VESPEL®

VESPEL®

EL

EC

TR

ICA

LM

OT

OR

S

BushingsUsed in all kinds of electrical motors,Vespel® bushings can run with orwithout lubrication depending on theapplication. A "straight" bushingdesign is adapted to radial loading buta "flanged" design can additionallybear axial loads and therefore elimi-nate the need for a washer.

Parts can easily be press-fitted intothe housing while maintaining verygood control of the inside diameter.In addition, the high PVcapabilityenables the length of the bushing tobe reduced.

In these types of application, a lowand constant coefficient of friction isrequired as well as wear and creepresistance.

The various Vespel® graphite filledgrades provide cost effective solutions.

plugs are parts that are directly fittedinto the rotor shaft with a slight interference.

Like washers, these parts have to takeaxial loads, and resist creep and wear.

Depending on the application, a lowor relatively high coefficient of fric-tion may be required, and unfilled SP1 or SP21 filled with graphite are the usual preferred choices.

During very severe use, Vespel® thrustplugs will not melt and thereforeguarantee the function.

WashersWashers take the axial load in electri-cal motors which means that whileproviding wear and friction resistanceas bushings do, they also have towithstand impact.

Due to the small loading area of suchcomponents, both pressure and veloc-ity conditions can be high, generatingexcessive frictional heat.

The creep resistance and the PVcapa-bility of Vespel® washers guaranteelong and reliable life of the equipment.

Noise, often generated by metallicparts running against each other, iseliminated.

Thrust plugsSpecifically used in windscreen wipers,window lift, sunroof, seat adjusting,differential lock motors, etc.,thrust

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11

Braking is the most important func-tion in a vehicle today and the mainemphasis is on safety.

Anti-lock braking systems regulatethe brake fluid pressure applied ateach wheel to avoid skidding andoptimize braking.

Wear pads are equipped with electricalsensors that detect when the liningmaterial is worn and alert drivers viaa light on the dashboard.

The properties of Vespel® enable it toresolve the technical problems in bothareas.

Anti-lock brakingsystemsUsed as valve components, (seats,balls) Vespel® parts provide excellentsealing due to their outstanding com-pressive behaviour. They also resisthigh impact and improve responsetime with their light weight.

Wear padsVespel® sensors are installed into themetallic support of brake pads. Thesensor insulates, both thermally andelectrically, the wire which connectsto a brake wear warning light.

Here the material has to provide alow and constant wear rate, withoutmelting; and without depositing anyfilm on the disc that would damage itby modifying the electrical contact.

VESPEL®

BR

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Gasoline and diesel injection systemsrequire supply and injection pumps.Depending on fuel type and function,they have different working pressuresand designs, but all need wear andfriction and/or sealing components thatcan guarantee life and performance.

Vespel® has excellent chemical com-patibility with various types of fuelswithout excessive swelling, whichensures the success of Vespel® partssuch as bushings, seal rings, bandsprings and valve seats.

12

Turbo chargers are characterized byvery high running speeds and hightemperatures. Turbo chargers aredevices where Vespel® can demon-strate its properties.

As ball bearing retainers, Vespel®

can improve response time of the turbocharger through low weight andinertia.

As wastegate bushings, Vespel® canprovide the required sealing withoutwear and abrasion of the shaft.

Similar benefits under these conditionshave been provenin Exhaust GasReturn (EGR) systems.

FUEL SYSTEMS

TURBO CHARGERS

Vespel® parts have a unique combina-tion of properties which has enabledthem to be used in a wide variety ofautomotive applications.

For example:

• Vacuum pump vaneswhere out-standing wear behaviour guaranteessealing without abrasion of housings,often in soft metal

• Engine belt tensionerswhich provide wear and friction character-istics while eliminating matingmaterial wear debris.

• Rubbing blocksin ignition distribu-tors to actuate breaker points, whichguarantee constant wear rate andresistance to vibrations at high temperature.

• Door hinge bushingswhich sur-vive paint oven temperatures andcleaning fluids while providing reli-ability of operation if there is anyloss of lubricant.

• Gear stick rollersfor automatic and manual transmissions whichhave low wear during intensive useconditions.

13

VESPEL®

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QU

IPM

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Besides all applications describedpreviously, many other opportuni-ties can be seen for Vespel® in areassuch as:

14

A

B

B

A

C

D

E

• Wheel disc nuts (B)• Steering systems (C)• Air conditioning (D)• Suspension systems (A)• High temperature engine

applications (E)

• Intake and exhaust systems (E)

• Piston rings (E)• Shock absorbers (A)

OP

PO

RTU

NIT

IES

15

Temp. Method Unit SP1 SP21 SP22 SP211 SP221 SP262Properties °C ASTM * *

Tensile strength, ultimate 23 D 1708 MPa 72.4 62 48.3 51.7 38.6 37.9260 36.5 30.3 26.2 24.1 19.3

Elongation, ultimate 23 D 1708 % 7.5 5.5 2.5 5.5 3.5 1260 7 5.2 2 5.3 0.7

Flexural strength, ultimate 23 D790 MPa 82.7 82.7 62.1 68.9 55.1260 44.8 48.3 37.9 34.5 31

Flexural modulus 23 D790 MPa 2482 3171 4826 2758 3445260 1448 1792 2758 1379 2205

Compressive strength 23 D695 MPaat 1 % strain 24.1 22.8 24.1 14.5 14.5 40at 10 % strain 112.4 104.8 93.8 75.8 78.6at 0.1 % offset 33.1 33.8 25.5 27.6

Impact strength, Izod, 23 D256 J/m 42.7 42.7notchedImpact strength, Izod, 747 320unnotched

Coefficient of frictionPV = 0.875 MPa.m/s 0.29 0.24 0.3 0.12 0.1PV = 3.5 MPa.m/s 0.12 0.09 0.08 0.05Max. PV MPa.m/s 12 10 3.6 3.6 12Wear rate at PV0.875 MPa.m/s m/s 10-10 17 - 85 6.3 4.2 4.9

Thermal conductivity 40 W/m.°C 0.29 0.46 0.89 0.42 2.53

Coefficient of linear µm/m.°C 50 41 27 41 26 13thermal expansion

Water absorption, D570 % 1.0 - 1.3 0.8 - 1.1equilibrium, 50% RH

Specific gravity D792 1.34 1.42 1.56 1.46 1.74

Deformation under load 50 D648 % 0.2 0.17 0.14 0.29 0.3

* Some values for the new compositions SP221 and SP262 are preliminary or have been extrapolated from initial test data .For more technical details related to the product compositions or to your typical application, refer to the Vespel® Design Handbook and con-tact your Local Sales Engineer.

Summary of typical properties of Vespel® SP polymide resins

VESPEL®

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Technical team • Handling your technical enquiries

• Assisting you with your developments

• Design & testing

• CAD, FEA

• New composition developments

Marketing team • Local qualified field engineers in

direct contact with customers

• Quoting in EU-currencies

• Wide knowledge of applications

• Product development support

Vespel® offer• Supply of finished parts

• Sites in USA, Japan and Europe

• Centralized services in Mechelen(Belgium)

• Quality ISO 9001

• Door-to-door delivery

• Tool design and parts production

• Machining services available

AMSTERDAM

BRUSSELS

LEUVEN

AACHENKÖLN

NAMUR

LUXEMBOURG

ZAVENTEM

MECHELEN

LIEGE

HASSELT

ANTWERPENGENT

E17

E19E1

9

E411

E411

E40

E313E17

E40

E40

CHARLEROI

PARIS

LILLE

KORTRIJK

BRUGGE

OOSTENDE

®

Requests for further information fromcountries not listed should be sent to:

Du Pont de Nemours (Belgium)Vespel® ProductsA. Spinoystraat 6B-2800 MechelenTel. ++32-15-44 10 11Fax: ++32-15-44 14 08

VespelOnly by DuPont

®

®

Printed in Switzerland H-00000 07/97

This information corresponds to our current knowledgeon the subject. It is offered solely to provide possiblesuggestions for your own experimentations. It is notintended, however, to substitute for any testing youmay need to conduct to determine for yourself thesuitability of our products for your particular purposes.This information may be subject to revision as newknowledge and experience become available. Since wecannot anticipate all variations in actual end-useconditions,DuPont makes no warranties and assumesno liability in connection with any use of this infor-mation. Nothing in this publication is to be consideredas a license to operate under or a recommendation toinfringe any patent right. Caution: Do not use in medicalapplications involving permanent implantation in thehuman body. For other medical applications, see"DuPont Medical Caution Statement", H-51459.